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55813190 | The objective of this research was to obtain optimum condition of eugenol production from clove oil using a central composite design method. The main process occured in the eugenol production was saphonification and neutralization processes. In order to optimize these processes, the ratio of NaOH/clove oil and temperature were studied as design variables i.e. ratio of NaOH/clove oil=1:2.5-1:3.5 while temperature was varied between 40 and 60oC. The yield of eugenol was considered as the main response in of this experiment. The result showed that the optimum condition was achieved when the temperature and the ratio of NaOH/clove oil were 50oC and 2.75:1, respectively and the yield was 39.17%. | 1 |
55813190 | Introduction Since the production of clove oil has reached 250 tons in 2011, Batang regency has been considered as one of the largest producers of clove oil in Indonesia (Widayat et al, 2011).The clove oil is mostly extracted from part of clove plants (Eugenia caryophyllata thunb) such as leaves, flower, and stem.The quality of cloves oil is determined by the content of phenol compound, especially eugenol (BSN, 2010) which is still considered as the main problem of clove oil in Indonesia.Currently, the clove oil still has high content of eugenol and it is higher than the National Indonesian Standard (SNI).It has been reported that most of clove oil at small medium entrepreneurship (SME) in Batang Regency have eugenol contents up to 80% (Widayat et al, 2014) .Besides eugenol, the clove oil is also determined by β-Caryophyllene, an impurities that decrease the clove oil quality (Widayat et al, 2014). Figure 1.The molecule structure of eugenol However, besides it is resulted from side product of clove oil, eugenol has potential for industries.Eugenol or Phenol, 2-methoxy-4-(2-propenyl) (Figure 1) is the main component of clove oil and it is colourless, has spicy taste and special odour which therefore it was mostly used for fragrance and flavour industries.The eugenol is also mostly utilized in the perfume industries, flavor concentrates and in the pharmaceutical industries as an antiseptic and anesthetic drug.Oyedemi et al. (2009) reported that eugenol is efficient for the metabolic activity of bacteria Listeria monocytogenes, Streptococcus pyogenes, Escherichia coli and Proteus vulgaris.Furthermore, Cheng et al. (2008) has utilized this compound and sinamaldehid as an anti-fungal for the type of fungus and Laetiporus sulphureus, which is considerable used as activity inhibitory.Shelly et al. (2010) used eugenol derivative such as methyl eugenol to effectively increase the fertility of insects.Sadeghian et. al., (2008) had utilized eugenol derivatives to inhibit the activity of the enzyme 15-lipogenase which is involved in many diseases such as asthma and lung cancer.The results showed that these compounds could inhibit the performance of the enzyme 15-lipogenase.Furthermore, Chami et al. (2004) also have tested eugenol as anti fungus Candida albicans.Vidhya and Devaraj (2011) experienced eugenol for inducing lung cancer, which showed inhibitory phenomena in lung cancer. The price of clove oil is determined by its purity, the clove oil with purity under 70% will have price of Rp 120.000,00/ kg, while the clove oil with purity 98 % have price of 500.000/kg.Therefore, extraction and separation of eugenol from clove oil is an essential step to obtain such valuable product.According to USP (United States Pharmacopeia) standard, eugenol product must have purity higher than 98 %. Another aspect for increasing eugenol contents is by implementation of chelating agent to reduce the darkness.The chelating agents that mostly used are as citric acid and sodium EDTA (Marwati et al, 2005).Commonly, this process can increase eugenol contents up to 80%.Another process for separation of eugenol from clove oil is by using saponification and distillation as well as fractionation.In this method, sodium hydroxide will be reacted with clove oil and then was neutralized by adding sulphuric acid or hydrochloride acid.The eugenol product then is separated using decantation and distillation process.This process could increase eugenol contents up to 82,6 % (minimum) (Anny, 2002;Sukarsono et al, 2003).However, the optimization is still required to estimate the associated variables in eugenol production.Therefore, the objective of this research was to conduct optimization of eugenol production from clove oil using neutralization process and fractional distillation by using Response Surface Methodology (RSM). | 2 |
55813190 | Procedure The experiments began with oil density measurement and specific volume of clove leaf oil.Prior to experiment, clove oil was purified using citric acid (Widayat et al, 2014).A 150 ml of clove oil and NaOH were added under specified ratios of variables.The saponification reaction occurred for 45 minutes, and then followed by decantation for 1 day.The formed soaps were then neutralized with hydrochloride acid and were reacted for 5 minutes.This process was continued by decantation for 15 minutes.The eugenl product ws purified by using distillation for 1.5 hours.The final product was collected and was measured for its volume and refractive index.The concentration of products was also analyzed by using GC and data was analyzed by using STATISTICA. Where: X 1 = Coded variables for ratio of oil to NaOH X 2 = Coded variables for temperature Y = Yield of eugenol (%) | 5 |
55813190 | Data Analysis The responses of this experiment were density, viscosity and eugenol concentration.The eugenol concentration was analyzed by using gas chromatography at Malang Polytechnic Laboratory.The liquid product was analysed by using gas chromatography (HP 5890, with HP 608 column) equipped with FID detector.The operating condition used helium as gas carries with flow rate of 20 ml/minute, temperature of 100-200 o C with temperature gradient 5 o /minute and initial time 5 minute.Detector temperature was 275 o C. The product was analysed with internal standard methods.6 μL eugenol standard solutions was added with internal standard (benzyl alcohol) 6 μL and 1 ml of solvent.The solution injected on GC equipment and conducted in triple runs.The response of detector was calculated with sample area divided internal standard area.The yield of eugenol was calculated according to Eq 1. | 6 |
55813190 | Chromatography Analysis Fig. 3 shows the chromatogram analysis of methanol(solvent), benzyl alcohol and eugenol with retention time of 3.39; 10.04 and 18.36 minute, respectively.According to this chromatogram, the eugenol contents in the product were varies between 75.10 to 96.00%.This result showed that the euogenol producton could achieve higher concentration of eugenol from clove oil. Figure 3a shows a chromatogram of eugenol and internal standard and Figure 3.b for sample product and both figures show similarities, although there was a small shift of retention time. | 7 |
55813190 | Response Surface Methods The results of statistic analysis was performed by developing mathematical model, t test, analysis of variance, pareto analysis as well as model validation.The polynomial equation of multi linear regression was proposed by following form: Where: Y = predicted response β 1, β 2 = linear coefficient for 1, 2 variable β 11, β 22 = squared term coefficient for 1,2 variable The variable or coefficients were obtained by determining the multi linear regression by using STATISTICA software.Through this software, the coefficients were obtained and showed by Eq 3. This equation represents correlation between yield of eugenol and realted parmeters to obtain the yield.However, this variable of X1 and X2 are still in coded variable.The real values of condition process must be determined inversely. In Eq 3, it is shown that the values of coefficient for X 1 and X 2 are negative.This leads to the fact that if the ratio of oil to NaOH (X 1 ) and temperature (X 2 ) increase then the yield of eugenol will decrease (for X 1 and X 2 >0).In addition, the interaction between X1 and X2 and also quadratic variable are positive, which means that the increase of both variables will also increase of the eugenol yield.The complete statistical analysis of coefficient by using multivariate variables in Eq 3 is shown by Table 2. Variance of mathematical model was analyzed and the results presented in Table 3. Table 3 can also be used to determine whether the independent variables simultaneously significant effect on the dependent variable.The degree of confidence was 0.05 (Bos et al, 2005;Lazic, 2004)).The parameters have F value more than p for all parameters except for X1 quadratic variable (F value = 0.0113 p=0.9221) and interaction variable(F=0.1759and p= 0.2953).The results of variance analysis support the t-test in Table 2 for X1 and X2 variable (single variable). It also shows that the mathematical model already in optimum condition (maximum / minimum) no stripes ascend and mathematical model can be used directly for optimization.Pareto diagram can be a help to assist determination of the most important parameter in the process (Lazic ,2004).Pareto diagram (Figure 4) show that a linear variable X2 has the smallest value.Therefore this variable can be neglected due to no having effect in the process.All histogram of variables don't cross the line p = 0.05.Pareto chart show quadratic variable of X22 which has a histogram near to line p = 0.05.This proofs that quadratic variable X22 has the most effect in the eugenol yield .This condition can be increased for obtaining the optimum condition.Figure 5 shows optimum condition in term of a surface response graph that consists of x and y axis as independent variable (X 1 and X 2 ) and z-axis as dependent variable or yield of eugenol (Y). Figure 5 has a minimum poin meaning that the process is already minimized.Mathematical model described by equations 3 was validated with experiments data (Figure 6). Figure 6 also shows that the mathematical model has lower significant regression value (R 2 =0.764).However, such value is still suficient to obtain the optimum condition. In Table 4, the critical value of dimensionless numbers for each variable.Critical dimensionless value obtained for X1 (ratio clove oil to sodium hydroxide) is -0.0109 and X2 (temperature) 0.3095.X1 and X2 critical value is substituted to equation 6 to obtained yield of eugenol.Yield of eugenol in minimum condition is 39.17%. | 8 |
55813190 | Discussion The clove oil has been purified and separated from its eugenol contents.Eugenol which is one of indicator for quality of clove oil has been considered also as an important product for food industries.The result shows that 75-96% eugenol can be extracted from cloe oil by using separation method of saphonification, and distillation. The Surface Response Method (SRM) has been employed for optimization and analysis of production and purification of eugenol from clove oil by using neutralization and fractionation distillation.The minimum yield was obtained as 39.17% under X 1 (ratio clove oil to sodium hydroxide) is -0.0109 (equal to 2.75:1) and X 2 (temperature) of 0.3095 (equal to 55 o C).The regression coefficient for the mathematical model was achieved at R 2 = 0.7642. The further research is required to increase the eugenol purity and yield.Conventional steam distillation is typically considered the best way to obtain essential oils including eugenol from clove oil.However, this method produces varying eugenol product qualities dependent upon the temperature, pressure and time used for distillation.An important point regarding steam distillation of eugenol oils is that the temperature involved in the process changes the molecular composition of the plant matter.However, in practice most essential oils including eugenol are obtained by distillation at rather elevated temperature, in order to optimize the yield.Other alternative were proposed to use process intensification through microwave, ultrasound or supercritical fluid extraction and distillation.However, their economical feasibility must also be considered.Further action is also required to investigate the eugenol risk to human in term of their use for food. | 9 |
54718100 | An experiment was conducted to investigate the effect of Butylated Hydroxy Anisole (BHA), Butylated Hydroxy Toluene (BHT), Pentoxifylline (PTX), Theophylline (TPY) and Theobromine (TBR) on cold protection ability of Murrah buffalo semen at room (22-25°C) and refrigerated temperature (4-7°C). Each semen sample was divided into six parts of equal volume and sperm concentration; the first was kept as a control and the remaining five were treated with BHA, BHT, PTX, TPY or TBR. Sperm motility, abnormal spermatozoa, live-dead count, hypo-osmotic swelling and acrosomal integrity were studied at room and refrigerated temperature for various incubation periods viz.; 0, 4, 8, 12 and 24 h at room and 0, 12, 24, 36, 48, 60 and 72 h at refrigerated temperature. Significant improvement in sperm motility, live-dead count, hypo-osmotic swelling and acrosomal integrity were observed in BHT, PTX and TPY fortified extender at room and refrigerated temperature for various incubation periods. From the present study it could be concluded that cold protection ability of buffalo semen can be improved through the addition of BHT followed by PTX and TPY. ( | 1 |
54718100 | INTRODUCTION Buffaloes in the Asian continent play an important role as a producer of milk, draught power, dung and other value added products.Their contribution to the national milk grid in India is around 50% in spite of the fact that the population of buffaloes is less than half of the total cattle population.Reproduction is the central trait in animal production throughout the world.High reproduction capacity increases economic efficiency in milk and meat production.Buffalo semen is known for its poor quality and freezability which is well documented in the literature (Roy et al., 1962;Sengupta, 1963).Motility as well as fertility of spermatozoa can be improved by incorporating various motility enhancing agents like pentoxifylline (PTX) (Yovich et al., 1984;Sikka et al., 1995), or antioxidants (Irvine, 1996;Perinaud et al., 1997).PTX increases cAMP level by a methylxanthine inhibition of phosphodiesterase and thus improves motility, capacitation and acrosome reaction (Yovich et al., 1984;Sikka et al., 1995).This increase in cAMP causes activation of protein kinase and phosphorylation of endogenous protein.Motility of spermatozoa is increased due to utilization of increased energy production by accelerating glycolysis and TCA cycle activity (Haesungcharern and Chulavatnatol, 1973). The antioxidants check the chemical breakdown of substrate resulting from oxidation.Antioxidant preservatives neutralize the free radicals that initiate and help propagate these reactions.The maintenance of sperm membrane phospholipids together with the susceptibility to peroxidation depends on adequate antioxidant properties, which reduce the risk of damage to spermatozoa and probably their lack of survival during storage (Strzeżek et al., 1999;Strzeżek, 2002).Thus, a deficiency of these fractions can affect the overall protection of the spermatozoa from oxidative damage, which can have a negative effect on sperm motility and fertilization. Among methyl xanthines, caffeine, PTX, Theobromine (TBR) and Theophylline (TPY) have been used.Methyl xanthine supplementation has resulted in better seminal characteristics in fresh and cryopreserved spermatozoa viz., Toluene (BHT), Pentoxifylline (PTX), Theophylline (TPY) and Theobromine (TBR) on cold protection ability of Murrah buffalo semen at room (22-25°C) and refrigerated temperature (4-7°C).Each semen sample was divided into six parts of equal volume and sperm concentration; the first was kept as a control and the remaining five were treated with BHA, BHT, PTX, TPY or TBR.Sperm motility, abnormal spermatozoa, live-dead count, hypo-osmotic swelling and acrosomal integrity were studied at room and refrigerated temperature for various incubation periods viz.; 0, 4, 8, 12 and 24 h at room and 0, 12,24,36,48,60 and 72 h at refrigerated temperature.Significant improvement in sperm motility, live-dead count, hypo-osmotic swelling and acrosomal integrity were observed in BHT, PTX and TPY fortified extender at room and refrigerated temperature for various incubation periods.From the present study it could be concluded that cold protection ability of buffalo semen can be improved through the addition of BHT followed by PTX and TPY.(Key Words : Buffalo Semen, Sperm Motility, Non-Eosinohilic, Butylated Hydroxy Anisole, Butylated Hydroxy Toluene, Pentoxifylline, Theophylline, Theobromine) motility and curvilinear velocity (Chauhan et al., 1983).The addition of methyl xanthine to sperm suspension seems to improve sperm function leading to better sperm fertilizing ability (Chauhan et al., 1983). Therefore, this study was an endeavour towards the improvement of chilled buffalo semen by using Butylated hydroxy anisole (BHA), Butylated hydroxy toluene (BHT), PTX, TPY and TBR as sperm motility promoting factors. | 2 |
54718100 | MATERIALS AND METHODS Four healthy Murrah buffalo bulls, 2.5 to 5.0 years of age with body weight varying from 300 to 700 kg and maintained under identical nutrition and management conditions at the National Dairy Research Institute, Karnal, India, were selected randomly from the herd for the study.Vaccination and deworming were done regularly as per the farm schedule. | 3 |
54718100 | Semen collection and evaluation The bulls were washed before taking to the site of collection.Semen was collected (Walton, 1945) using an artificial vagina (AV) of 12 inches size "Danish Model" with smooth lining, over a male dummy bull once a week.On each collection, two ejaculates were taken in succession, (Foster et al., 1970) and each ejaculate was preceded by a period of sexual preparation consisting of at least two false mounts separated by about one minute restraint.The second ejaculate was collected about 15 minutes after the first.Immediately after collection, each ejaculate was placed in a water bath at 30°C and examined for various physical attributes viz.volume, mass activity, sperm motility and sperm concentration. Semen volume was collected in a 15 ml graduated metal free glass tube (0.1 ml accuracy).Mass motility was assessed just after the semen collection.Gross swirl rating (GSR) of undiluted semen was performed within one min of collection.Two 10 μl aliquots of undiluted semen were placed separately on a warmed slide located on a stage warmer (37°C) and scored on a scale of 0-4 using a 10X objective lens on a phase contrast microscope (Nikon Eclipse E600, Tokyo, Japan).Motility was expressed qualitatively on a motility scale (0-4) as described by Matharoo et al. (1985).Semen with +3 or below grade was used for further processing.Manual progressive motility and percentage motile spermatozoa were determined by placing 100 μl of undiluted semen into pre-warmed tubes containing 900 μl of Tris buffer and mixing.Twenty microliters of diluted semen was placed on a warmed glass slide (37°C) and allowed to spread uniformly under the cover slip.Strength of motility rating was scored using 200× magnification with a phase contrast microscope (Nikon Eclipse E600, Tokyo, Japan) equipped with a 37°C-heated stage.Percent progressive motility (0-100%) was measured at five representative areas of the slide.The average of the five scores for each category was recorded.If the difference between two consecutive counts exceeds 10 percent, two new counts were performed. | 4 |
54718100 | Experimental design A total of 9 double ejaculates was taken from 4 Murrah buffalo bulls (MU) making a total of 72 ejaculates.Every ejaculate was divided into six parts, each containing an equal volume and number of sperm, before room and refrigerated temperature incubation, and subjected to the following treatments: Each semen sample was diluted with PBE at 30 million sperm/ml after adding the aforementioned sperm motility enhancers. Live-dead count : Semen samples were kept at 37°C for 30 min before analysis.Forty microlitre (μl) of neat semen was mixed in a micro-centrifuge tube with 400 μl eosinnigrosine staining solution.The suspension was kept for one minute at room temperature (27°C).Then, a 12 μl droplet was transferred by pipette to a labelled microscope slide (pre-warmed to 37°C) where it was smeared.Duplicate smears were made from each sample, allowed to air dry at room temperature and examined directly.About 200 sperm were assessed at a magnification of 1,000× under oil immersion with a high-resolution 100× bright field objective (not phase contrast).Sperm that were white (unstained) were classified as non-eosinophilic and those that showed any pink or red colouration were classified as dead, with the sole exception of sperm with a slight pink or red appearance restricted to the neck region ('leaky necks'), which were assessed as eosinophilic. Morphological abnormality : The same slide which was made for eosin-nigrosine staining was used for calculating morphological abnormality.A drop of oil was applied to the cover-slip and the semen was examined at 1,000× under a DIC (differential interference contrast) microscope.If the preparation was too thick, examination was difficult because many sperm heads were laid on their edges rather than flat.Each cell, even in thin preparations, was usually not totally in one focal plane and it was necessary therefore to focus up and down slightly on each cell.About 200 spermatozoa were counted in different fields and the percentage of abnormal spermatozoa was calculated as follows: ( ) Hypo-osmotic swelling test (HOST) : The hypo-osmotic swelling test was performed according to the methods described by Correa and Zavos (1994).Sperm tail curling was recorded as an effect of swelling due to influx of water.A total of about 200 spermatozoa were counted in different fields at 400× magnification under a DIC microscope.The total proportion of swollen spermatozoa was calculated by dividing the number of reacted cells by the total spermatozoa counted in the same area and multiplying the figure by 100.The proportion of swollen spermatozoa from a control sample was subtracted from this value. These spermatozoa were classified into four different classes according to the presence of the following swelling patterns (Takahashi et al., 1990), namely, A, No swelling, no membrane reaction; B, Swelling of tip of tail; C, Different type of hairpin-like swelling pattern or swelling of mid-piece and D, Complete tail swelling.Spermatozoa displaying B, C or D were considered positive for the HOST test. Acrosome integrity : Staining was carried out as described by Hancock (1952).A thin smear of extended semen was prepared on a non-greasy, clean and dry slide.The smear was air-dried at room temperature for at least 10 minutes in a current of warm air.The smear was fixed by immersion in buffered formal saline (10 percent) for 15 minutes, then washed in running tap water for 15-20 minutes and dried.Again the slide was immersed in buffered Giemsa solution for 90 minutes, rinsed briefly in distilled water and dried.The dried smears were studied at 1,000× under a light microscope using oil immersion without a cover glass.Each time about 200 spermatozoa were counted for acrosomal status after staining. | 5 |
54718100 | Statistical analysis The data were subjected to analysis of variance to study the effect of treatments on different physical and morphological attributes of semen during various intervals of storage.The following statistical models were used for ANOVA as described by Snedecor and Cochran (1989) and the significant difference between two parameters was evaluated through LSD. Where, Y ijk = k th observation of j th stage or interval of preservation, μ = Overall mean, I j = the effect of j th stage or interval of preservation, (EI) ij = The effect of (ij th ) additive-interval or stage interaction, e ijk = The Random Error, NID (0, σ 2 e) Descriptive statistics (SAS 8.2) were performed on the data to determine normality. | 6 |
54718100 | Performance of additives at room temperature (22-25°C) A comparative study of performance of various additives at room temperature was carried out and the data are shown in Table 1 to 3. Sperm motility (per cent) : Analysis of data revealed significant (p<0.05)differences in individual motility between additives at various hours of incubation in buffalo bull semen. Sperm motility (%) was higher in BHT, PTX, TPY and TBR than in BHA and the control group at 0 hour in MU bull semen (Table 1).For the remaining periods, motility (%) was significantly (p<0.01)greater in BHT, PTX and TPY than in the Control (C), BHA and TBR for MU bull semen.Overall, results showed a significant deterioration in motility after each preservation stage.Motility was found to be better preserved in extender fortified with BHT, PTX and TPY. Non-eosinophilic count (per cent) : Non-eosinophilic count was significantly (p<0.05)higher in BHT, PTX and TPY than in TBR, BHA and C groups at 0 h in cattle bull semen (Table 1). TPY gave a significantly (p<0.05)better result compared to BHA, PTX and TBR in terms of noneosinophilic count (%) at 0 h in MU bull semen (Table 1).BHT, PTX and TPY supported the sperm non-eosinophilic count significantly (p<0.05)better than all other additives in MU bull semen after 24 h of incubation. Overall, results showed a significant deterioration in non-eosinophilic count after each preservation stage.Damage to spermatozoa was found to be least in extender fortified with BHT, PTX and TPY. Sperm abnormalities (per cent) : Tail abnormality (per cent) was the most prominent out of various types of abnormalities in Murrah bull semen (Table 2).There was no difference in various additives in head abnormality (per cent) for most of the periods, except for 24 h in MU bull semen.All additives resulted in significantly (p>0.05) less head abnormality (per cent) than the control group at 0 h.Head abnormality in BHT, PTX and TPY was significantly (p<0.01)less than the control in MU bull semen after 24 hours of incubation.No difference in mid-piece abnormality (per cent) was observed between additives at any incubation period, except for BHT and TPX in MU which were significantly (p<0.05) less than the control after 24 h of incubation.The tail abnormality (per cent) was significantly (p<0.01)less in BHT, PTX and TPY in MU bull semen.As tail abnormality (per cent) constituted the major portion of total abnormality (per cent), so the same trend was visible in total abnormality (per cent) as in the tail abnormality (per cent). Overall, the results showed a significant increase in spermatozoal tail and total abnormality after each preservation stage, however, the head and mid-piece abnormalities were largely unaffected.Tail and total abnormality was found to be least in extender fortified with BHT, PTX and TPY. Acrosomal Integrity (per cent) : Initially, acrosomal integrity (per cent) in BHA, BHT, PTX, TPY and TBR was significantly (p<0.01)higher than the control when used as semen additive in PBE for the extension of SW, KF and MU semen (Table 3). BHT, PTX and TPY addition resulted in significantly (p<0.05)better acrosome integrity than for the control, BHA and TBR addition in bovine bull semen after 24 h of incubation.Overall, results showed a significant deterioration in intact acrosome (per cent) after each preservation stage.From the results, it was evident that spermatozoa acrosome integrity was best preserved in extender fortified with BHT, PTX and TPY after 24 h of storage. Hypo osmotic swelling test (per cent) : There was no difference in HOST (%) value of different additives at 0 h in MU bull semen (Table 3).BHT, PTX and TPY were significantly (p<0.01)better than C, BHA and TBR in MU bull semen. Overall, results showed a significant deterioration in plasma membrane integrity (per cent) after each preservation stage.The plasma membrane integrity as measured by HOST was found to be better preserved in extender fortified with BHT, PTX and TPY. | 7 |
54718100 | Performance of additives at refrigerator temperature (4-7°C) A comparative study of performance of various additives at refrigerator temperature was carried out and the data are shown in Table 4 to 6. Sperm motility (per cent) : Initially sperm motility (per cent) of MU bull semen was significantly (p<0.05)higher in PBE fortified with BHT, PTX and TPY than in BHA, TBR and control groups at refrigerator temperature (Table 4).BHT, PTX and TPY were significantly (p<0.05)better than BHA, TBR and control groups in MU bull semen after 72 h of incubation. Overall, the results showed a significant deterioration in motility after each preservation stage.Motility was found to be better preserved in extender fortified with BHT, PTX and TPY. Non-eosinophilic count (per cent) : No difference in any of the additives for non-eosinophilic count was manifested in MU bull semen at 0 h of refrigerator temperature (Table 4).BHT, PTX and TPY supplemented groups were significantly (p<0.05)superior to the control group in MU bull semen after 12 h of incubation at refrigerator temperature.Subsequently for all periods of incubation, non-eosinophilic count was significantly (p<0.01)higher in BHT, PTX and TPY supplemented groups than in BHA, TBR and control groups in MU bull semen. Overall the results indicated that PBE fortified with BHT, PTX and TPY could support the preservation of livability of spermatozoa to the maximum extent in storage at refrigerator temperature (4 to 7°C). Sperm abnormalities (per cent) : Tail abnormality was the most prominent in MU bull semen (Table 5). There was no significant (p>0.05)difference between head and mid-piece abnormality of any of the additives for any period of incubation at the refrigerator temperature under study.The tail abnormality was significantly (p<0.05)lower in PBE fortified with BHT, PTX and TPY than in control groups up to 72 h of incubation at refrigerator temperature in MU bull semen.As the tail abnormality constituted the major portion of total abnormality, so the same trend was found in total abnormality.Overall, the results showed a significant increase in spermatozoal tail and total abnormality after each preservation stage at refrigerator temperature (4 to 7°C), however, the head and mid-piece abnormalities were largely unaffected.Tail and total abnormality was found to be significantly (p<0.05) less in extender fortified with BHT, PTX and TPY. Acrosomal Integrity (per cent) : Initially there was no significant difference among any of the additives in acrosomal integrity for MU bull semen (Table 6).But this trend was changed subsequently when BHT, PTX and TPY were significantly (p<0.05)better than control, BHA and TBR groups in MU bull semen after 72 h of incubation at refrigerated temperature. Overall, the results showed a significant deterioration in the acrosome integrity up to 48 h, thereafter there was not much degradation of integrity.From the results, it was evident that spermatozoal acrosome integrity was best preserved in PBE fortified with BHT, PTX and TPY in MU bull semen after 72 h of storage. Hypo osmotic swelling test (per cent) : There was no difference for HOST (per cent) among the various additives initially in MU bull semen (Table 6). But this trend was changed between periods of incubation where reaction of sperm to hypotonic medium was significantly higher in PBE fortified with BHT, PTX and TPY than control, BHA or TBR fortified groups with variable degree of significance (p<0.01 to 0.05). Overall, the results showed a significant deterioration in the plasma membrane integrity up to 48 h, thereafter there was not much degradation of integrity.After 72 h of storage, it was evident that the plasma membrane integrity as measured by HOST was best preserved in PBE fortified with BHT, PTX or TPY in MU bull semen. | 8 |
54718100 | DISCUSSION Mammalian spermatozoa are extremely sensitive to oxidative damage (Lucy, 1972).Lipid peroxidation plays an important role in spermatozoon ageing, shortening life-span and affecting the preservation of semen for artificial insemination (Alvarez and Storey, 1982).Maintenance of sperm membrane phospholipids and susceptibility to peroxidation depends on adequate antioxidant, which reduces the risk of damage to spermatozoa and increases their survival chances during storage (Strzeżek et al., 1999;Strzeżek, 2002).Thus, a deficiency of these fractions can affect the overall protection of the spermatozoa from oxidative damage, which can have a negative effect on sperm motility and fertilizing ability.The process of peroxidation induces structural changes, particularly in the acrosomal region of the sperm cell, a fast irreversible loss of motility, deep change in metabolism and a high rate of intracellular component release (John and Mann, 1977a).In vitro studies have shown BHA and BHT to act as free radical scavengers which protect cell membrane against lipid peroxidation (Beconi et al., 1993).During the process of freezing, spermatozoa have to undergo cold shock which increases their susceptibility to lipid peroxidation (John and Mann, 1977b;John et al., 1979;Pursel and Park, 1985).Stimulatory effects of methyl xanthine on capacitation and acrosome reaction have also been demonstrated.Overall, the addition of methyl xanthine to sperm suspension seems to improve sperm function leading to better sperm fertilizing ability (Chauhan et al., 1983).Similar results were also observed in the present study while fortifying the PBS for dilution of bovine semen with PTX and TPY.However, desirable results could not be achieved by fortification of PBE with BHA and TBR.Killian et al. (1989) hypothesized that BHT serves as a scavenger of free oxygen radicals, associated with the diluent and sperm, to minimize damage to the sperm motility apparatus and membranes, and which also may affect motility indirectly.Graham and Hammerstedt (1992) reported that BHT with no egg yolk present reduced sperm motility, but addition of egg yolk in BHT-treated sperm improved motility, and lipid vesicles in milk and egg yolk (Hu et al., 2006) interacted synergistically with BHT to protect spermatozoa from cold shock.Anderson et al. (1994) reported that the use of BHT improved viability of frozen and thawed sperm and inactivated lipid containing viruses.In the present study also, BHT fortification in PBE for extension of bovine bull semen has improved the viability of sperm. Methyl xanthine supplementation resulted in better seminal characteristics in fresh and cryopreserved spermatozoa viz., motility and curvilinear velocity (Chauhan et al., 1983).Fayed and Hattab (1991) observed that supplementation of TPY (0.5 ng/ml) improved the keeping quality of chilled semen up to 5 days.PTX may be added to boost the motility of the sperm (Aitken et al., 1993).PTX increases the duration of activity of spermatozoa by increasing the level of cyclic adenosine monophosphate (cAMP) or by reducing the decomposition of cAMP (Perry and Higgs, 1998) by stimulating the enzyme adenylate cyclase (AC stimulator).Thus, in the present study, improved motility was observed in bovine bull semen after fortification of PBE with BHT, PTX and TPY. Sperm abnormalities (per cent) are one of the most significant indicators of subsequent fertility in a bull (Saacke, 1990).Disturbance in spermatogenesis gives rise to morphological abnormalities.The relationship between sperm morphology and fertility has been evaluated in several studies.Abnormal sperm morphology has been correlated with reduced fertility in cattle (Sekoni and Gustafsson, 1987;Barth and Oko, 1989;Correa et al., 1997;Thundathil et al., 2000) and buffalo (Sengupta and Bhela, 1988).Bull fertility depends upon morphologically normal spermatozoa being present in the ejaculate (Tharwat, 1998) and is hardly affected if abnormal spermatozoa do not exceed 15-20 per cent (Pant et al., 2002).In particular, the occurrence of abnormal sperm head morphology is associated with lower fertility in the bull (Saacke and White, 1972;Sekoni and Gustafsson, 1987).However, a number of other studies have shown no correlation between sperm morphology and fertility (Bratton et al., 1956;Linford et al., 1976) with clear associations between normal bull sperm morphology and fertility continuing to remain elusive (Johnson, 1997).In the present study the increase of abnormality (per cent) is mainly in the tail which suggests that osmolality change in the media may be responsible for this increase as suggested by Joshi et al. (2006).The additives responsible for resisting change in the morphology of spermatozoa are BHT, PTX and TPY. The addition of methyl xanthine to sperm suspension seems to improve sperm function leading to better sperm fertility (Chauhan et al., 1983).These authors found that when BHT-treated ram sperm were subjected to cold shock, acrosome damage was reduced, and the percentage of motile sperm was higher than for untreated sperm.Similarly, in the present study, methyl xanthine inclusion in the PBE for extension of bovine bull semen resulted in reduced acrosome damage. Antioxidant preservatives (like BHA, BHT and methyl xanthines) are used to stop auto-oxidation that causes a chain reaction in the unsaturated fatty acids in oils and lipid, and help in slowing down the oxidation of fats and oils.Oxygen reacts preferentially with antioxidants rather than oxidizing fats or oils, thereby protecting them from spoilage.BHA is a synthetic analogue of vitamin E and acts by reducing oxygen radicals and interrupting the propagation of oxidation processes.However, in the present study, BHA has not shown its motility enhancer role. BHT is an organic soluble molecule which modifies the properties of lipid bilayers and membrane of sperm cells (Hammerstedt et al., 1978).BHT readily incorporates into sperm membranes and prevents membrane damage after exposure to cold (Anderson et al., 1994).Use of spin labels and electron spin resonance techniques suggests that BHT acts on membranes to increase fluidity and to render them less susceptible to cold shock (Anderson et al., 1994).These reports explain the superiority of BHT as an additive over others as evidenced from the present results.Thus, future prospects for use of fortified PBE for the preservation of MU bull semen could be recommended as also supported from the results of acrosome integrity testing.Similarly, Hammerstedt et al. (1978) found that sperm from bulls and rams treated with 0.5 mM BHT were protected from membrane damage during cold shock.Addition of 0.5 mM BHT to whole milk extender during semen processing did not affect bull non-return rates (Anderson et al., 1994). PTX, TPY and TBR are methylxanthine phosphodiesterase inhibitors which reduce super oxide anions responsible for DNA apoptosis when used in a concentration of 3.6 mM (Maxwell et al., 2002).In the present study, TBR was not able to perform well as a semen additive, unlike PTX and TPY.Similarly, Vega (1997) reported that addition of PTX (6.0 mM) prolonged the viability of post-thaw bovine semen.Apart from modulation of sperm function, a protective effect on sperm membrane by PTX has been demonstrated (Vega, 1997).This effect may be ascribed to neutralization of reactive oxygen species (ROS) and reduction of lipid peroxidation (Vega, 1997).The use of BHT improved viability of frozen and thawed sperm and inactivated lipid containing viruses (Anderson et al., 1994).In the present study, BHT, PTX and TPY being oxygen radical scavengers, supported the preservation of viability of spermatozoa, in agreement with other studies.So, further studies should be carried out to standardize the optimum concentration of TBR to be incorporated in PBE for extension of Murrah bull semen in order to obtain its maximum benefit. | 9 |
86380370 | To gain knowledge of the fat characteristics of walnut varieties in different production areas of Shanxi Province, kernel oil content and its fatty acid composition of 6 walnut varieties were analyzed by using soxhlet extraction method and gas chromatography. The experiment sites were Yicheng and Tunliu. Yicheng has 800 m of altitude and 11 oC of annual mean temperature while Tunliu has 1100 m of altitude and 9.3 oC of annual mean temperature. The results indicated between Yicheng and Tunliu County, the most variety’s oil content was increased with increasing of altitude, but had no significant difference (64.9% > 64.3%, P > 0.05). Both the content of oleic acid and linoleic acid showed a significant difference between Tunliu and Yicheng, and there is a negative relationship between the contents of oleic and linoleic acid. Annual mean temperature has an obvious influence on α-linolenic acid (ALA) content of walnut. The content of ALA from Yicheng with higher annual mean temperature is higher than that from Tunliu with lower annual mean temperature. The nutrition analysis showed that Tunliu’ walnut kernel has a lower saturated fatty acids (SFA) (7.6% < 8.2%, P < 0.05) and a higher unsaturated fatty acids (UFA) (92.5% > 91.8%, P < 0.05) compared to Yicheng, respectively, but the polyunsaturated fatty acids (PUFA) content of Yicheng was higher than that of Tunliu (76.3% > 68.5%, P < 0.05), and its ratio of N-6/N-3 was also better compared to Tunliu (5.4:1 < 5.9:1). These results showed that with the different altitude and annual mean temperature, the walnut nutrition of fat is also different. Higher altitude and lower annual mean temperature can help to produce oleic-rich walnut while lower altitude and higher annual mean temperature is helpful for the higher content of ALA in walnut kernel. | 1 |
86380370 | Introduction Walnut kernel contains around 60-70% of oil, and can be praised as "the oil store on the tree" (Li et al., 2009).Walnut is a rich source of energy for life.People prefer plant oils to animal fat due to concerning about animal cholesterol (Pyorala, 1987).Plant oils don't contain any animal cholesterol; but it contains a large amount of unsaturated fatty acids (UFA) that benefit human health.The UFA content of walnut oil is more than 90%. To obtain the perfect nutrition characteristics of fatty acid composition of walnut, a lot of investigations have been done about variety (Wang et al., 2004;Chen et al., 2007;Wu et al., 2007).However, the results are not quite consistent even the same cultivars.It is reported that the external site conditions including altitude, air temperature, average annual relative humidity, longitude, may affect the single fruit kernel weight, accumulation of saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) during the plant growing season (Zhang et al., 2011;Li Guo et al., 2007;Xu et al., 2009).In order to gain knowledge of the fat characteristics of walnut in different production areas, the effect of production area on walnut oil quality is necessary to be investigated.Shanxi belongs to mountainous region which develops different climate conditions.Moreover, its total plant area of walnut is also large (Cheng, 2011), so we selected Shanxi as experimental site to determine the effect of producing region of walnut on oil quality. | 2 |
86380370 | Materials Walnut samples were collected at Yicheng County and Tunliu County, in Shanxi province of China during 8-9, 2012.The condition data of the two sites were shown in According to the method 3-5 g of walnut kernel powder was weighted, wrapped with filter paper and laid in Soxhlet extractor.A 50-60 ml solvent of petroleum ether (60-90 ºC) was added and refluxed for 8h.The oil content of walnut kernel was determined gravimetrically after complete evaporation of solvent to the dryness at 45 ºC using a rotary evaporator. | 3 |
86380370 | Analysis of Fatty Acids by Gas Chromatography 20-30mg of walnut oil was weighted and esterified through sodium methoxide.Fatty acid methyl esters were analyzed on a Lufen company gas chromatograph GC6500 with flame-ionization detector.The glass column packed with 20% DEGS on Chromsorb (4 mm i.d.× 1.1 m length) was employed; N2 was used as a carrier gas; the column temperature was 190 ºC and the injector and detector temperatures were 250 ºC.The content of fatty acid was obtained by calculating the peak area percentage method.Figure 1 is the typical fatty acid chromatography of Liaoning No.1 walnut oil from Tunliu County. | 4 |
86380370 | Analysis of Oil Content and Fatty Acid Content of Walnut in Different Production Areas 6 varieties of walnut were selected to inspect the effects of two different production areas (Tunliu and Yicheng) on walnut oil content and fatty acid content.Figure 2 showed that the oil content of the same varieties from Tunliu was more than that of Yicheng except Zhonglin series (No.1 and No.3), but the average value of Tunliu was a little higher than that of Yicheng (64.9% > 64.3%).The factors (Li et al., 2010) influencing oil content includes genetic quality, seed maturity, and fruiting number, etc.In our study these factors were controlled to be as similar as possible.However, there are still some of differences of climatic conditions such as altitude and yearly precipitation.Altitude has a positive effect on walnut single fruit kernel weight and kernel percent (Zhang et al., 2011), but it can be considered with water factor as far as the oil content.Altitude of Tunliu is about 1100m more than 800 m of Yicheng, and the yearly precipitation is also higher than that of Yicheng.During fruit development, the moisture of soil was higher in Tunliu of high altitude than that in Yicheng of lower altitude, and water help to the nutrition absorption for the synthesis of oil, which was seen in most of variety except for Zhonglin No.1 and Zhonglin No.3. Figure 2. The oil content of walnut with increasing of altitude Frost-free period means plant growth period, but even the frost-free period in Yicheng was approximate to one month longer than that in Tunliu, there was not obvious increment in oil content.This indicated that the synthesis of oil can be related with altitude and water rather than plant growth time.The pH value of soil can have different influences on oil content due to walnut variety.Zhonglin series including Zhonglin No.1 and Zhonglin No.3 were suitable in milder alkaline soil of Yicheng, while higher pH value of soil of Tunliu was more suitable for the most of varieties.Tree-oil crops preferred calcareous soils (Li et al., 2010) where higher pH value of soil was usually seen.However, the content of oil of the most varieties from Tunliu was more than that from Yicheng.It was found that the climate played a more important effect on walnut compared to soil (Cao, 1994).From the view of climate, the oil content of higher altitude was more than that of lower altitude, but the difference was insignificant (P > 0.05).This might be due to the little sample number. From Tables 2-3, there was no difference in main composition kinds of fatty acid.But there was significant difference in oleic content, the major monounsaturated fatty acid (MUFA) in walnut; the average content from Tunliu was more than that from Yicheng as far as MUFA (23.8% > 15.0%, P < 0.05).On the contrary, linoleic acid content of Tunliu was less than that of Yicheng, (58.4% < 64.2%, P < 0.05).Higher altitude can produce the higher oleic acid content, especially with lower annual mean temperature.An extremely negative correlation is observed between the contents of oleic and linoleic acid in cameillia oleifera fruit trees (Wang et al., 2008) and this same relationship was also proved existed in walnut trees in our results.This phenomenon probably rises from the saturate conversion of the two fatty acids of same carbon chain length.Although the samples are from two different production areas, the content relationship between oleic acid and linoleic acid appears to be same.Therefore, the differences of oleic and linoleic acid from two production areas can be considered as one index of fatty acid to compare.Our results showed that Tunliu is suitable for MUFA-rich or oleic-rich walnut, in other words, Yicheng is suitable area for linoleic acid-rich walnut. | 5 |
86380370 | Comparison of Nutrition Characteristics of Walnut From Two Production Areas The nutrition characteristics of walnut fatty acids was compared on Tables 4-5.Tunliu has a lower of SFA (7.6% < 8.2%, P < 0.05) and a higher UFA (92.5% > 91.8%, P < 0.05) compared to Yicheng, respectively, but the polyunsaturated fatty acids (PUFA) content of Yicheng was higher than that of Tunliu (76.3% > 68.5%, P < 0.05), and its ratio of N-6/N-3 was also better compared to Tunliu (5.4:1 < 5.9:1).Air temperature has a positive effect on PUFA amount (Li et al., 2007).Annual mean temperature of Yicheng (11.0 ºC) was higher than that of Tunliu (9.3 ºC).However, there was no difference in PUFA/SFA.This indicated that the unsaturated conversion of the two fatty acids of same carbon chain length are confined to definite unsaturated acids rather than saturate acids, despite of the difference of annual mean temperature in two production areas.There was a significant difference of α-linolenic acid content (ALA) between Yicheng and Tunliu.The content of ALA of every variety from Yicheng was higher than that of Tunliu correspondingly (Figure 3).And then the average of α-Linolenic acid was also more than that of Tunliu (12.1% > 10.2%, average value).Annual mean temperature can affect the synthesis of ALA.With the annual mean temperature the content of ALA increases (Li et al., 2007).In our study, higher annual mean temperature of Yicheng (11.0 ºC) had an increased amount of ALA compared to Tunliu (9.3 ºC).This result can be explained for the differences of annual mean temperature in production areas.Higher annual mean temperature was always accompanied with longer frost-free period and illumination time, and these climate conditions can be also helpful to ALA biosynthesis. Figure 3. ALA content of walnut between Tunliu and Yicheng ALA is the precursor of synthesize EPA (eicosapentaenoic acid) and DHA (Docosahexaenoic acid), and have also physiologically active like decreasing blood lipid, decreasing blood pressure, antithrombosis and preventing and curing athrosclerosis, etc.For the appropriate ratio of the N-6 to N-3 fatty acids (Simopoulos, 2002) also needs an important increase in ALA concentration.So it is strongly advised that the higher annual mean temperature should be considered to produce the ALA-rich walnut. | 6 |
85002311 | The effect of blocking the ultraviolet (UV) solar radiation using a UV-absorbing low density polyethylene (PE) film on tomato crop yield and fruit quality was evaluated in a two-year study in two arched roof greenhouses located in Central Greece. The UV-A and UV-B radiation transmission values of the greenhouse covered by the UVabsorbing PE film during the first year were 0.4% and 1.2%, respectively and increased to 0.8% and 1.3% in the 2nd year, while the respective values in the greenhouse covered by a traditional PE film were 20.7% and 12.5% during the 1st year and 28.7% and 26.7% during the 2nd year. Under the UV-absorbing film the number of insect injured fruit was reduced and the marketable yield was similar or higher than that under the common PE film, while fruit quality characteristics (size, shape), nutritional value (ascorbic acid and lycopene) and organoleptic quality (pH, titratable acidity and total soluble solids) were similar under both covering materials. Moreover, the reduction of incoming UV radiation had an appreciable effect on fruit skin color, indicating an effect on pigments other than lycopene. Additional key words: fruit quality; insects; polyethylene; transmission; ultraviolet radiation; UV-stabilizers. | 1 |
85002311 | Lycopene content and ascorbic acid are crucial quality parameters (Giuntini et al., 2005) but while ascorbic acid is present in all vegetables (Davey et al., 2006); lycopene is found only in red tomato and watermelon [Citrullus lanatus (Thunb.)]fruit (Bramley, 2000).Lycopene is considered one of the most important carotenoids in European and North American diet (Giuntini et al., 2005) and has attracted considerable interest as a health promoting phytochemical (Tadmor et al., 2005). The aim of this work was to study the effects of UV-absorbing greenhouse covering films on fruit yield and quality characteristics of a common tomato cultivar (Solanum lycopersicum L., cv.Belladonna) in Greece. | 2 |
85002311 | Greenhouse facilities and plant material The experiments were conducted during spring and summer 2003 and 2004 (transplanting at the end of February until July) in two similar arched roof greenhouses, N-S oriented, located at the University of Thessaly farm (39°22'N 22°44'E, altitude 85 m), on the continental area of Eastern Greece.The geometrical characteristics of each greenhouse were as follows: eaves height of 2.9 m; ridge height of 4.1 m; total width of 8 m; total length of 20 m; ground area of 160 m 2 , and volume of 524 m 3 .The greenhouses were equipped with two continuous side roll-up windows located at a height of 0.6 m above the ground with a maximum opening area of 27 m 2 (two vents of 15 m length × 0.9 m opening height) for both vents.A flap roof window was also located longitudinally on the whole greenhouse roof (20 m long) with 0.9 m maximum opening height (18 m 2 opening area).The vents were controlled automatically via a controller (Macqu, Geometions SA, Athens, Greece) and opened in steps; they began to open when greenhouse air temperature exceeded 22°C, and reached their maximum aperture when temperature reached 25°C. | 3 |
85002311 | Introduction Greenhouses create an ideal environment not only for crop but also for pest and disease development.Chemicals pest and disease control are common practice for fresh vegetable protection.As an alternative, many growers use insect proof screen use, placing them in the ventilators.Thus, screening reduces ventilation (Katsoulas et al., 2006;Teitel, 2007) making the high internal temperature of Mediterranean greenhouses during summer even worse. A complement to using insect screens is the use of a UV-absorbing film for greenhouse covering, which creates a light environment unfavourable to harmful insects.UV-absorbing films do not only block insect pests but also reduce spread of insect-borne viruses (Raviv & Antignus, 2004).Furthermore, UV-absorbing films can reduce crop diseases caused by a range of fungi that use UV as an environmental cue for sporulation (Nigel et al., 2005). It is well documented that UV-absorbing films suppress several foliar diseases (Raviv & Antignus, 2004), but their impact on crop yield and quality still needs investigation.In Israel, no significant differences were found on growth, yield, maturation time and fresh and dry weight values of tomatoes (Solanum lycopersicum L.) grown under UV-absorbing films (Raviv & Antignus, 2004).In studies carried out in Spain, an increase in tomato yield was reported when UV-absorbing films were used (González et al., 2004;Monci et al., 2004).Kittas et al. (2006) compared the effect of UV-absorbing films on eggplant (Solanum melongena L.) crop behaviour and production.In the absence of UV radiation eggplants were taller (21%), with a larger leaf area (17%) and produced more marketable fruit yield.The adoption of UV-absorbing films by growers as an alternative technique to chemical pest and disease control seems promising as long as fruit yield and quality and concomitantly the anticipated economic return is not negatively affected. In terms of nutritional quality, it is well established that light affects lycopene content (Cox et al., 2003) as well as ascorbic acid (Giuntini et al., 2005) and other compounds that contribute to fruit composition.Some authors report that UV radiation affects plant secondary metabolism by restricting the production of UV-absorbing compounds including flavonoids and other phenolics (Allen et al., 1998;Caldwell et al., 2003).These compounds significantly affect fruit composition and therefore fruit nutritional quality.Effects of UV-absorbing covers on tomato quality or 18°C during the day and interrupted it at 16°C during the night or at 20°C during the day.Greenhouse soil was covered by a white on black plastic sheet. One greenhouse was covered by a common low density PE film (C-PE, Plastika Kritis S.A., Heraclion, Crete, Greece) and the second one by a UV-absorbing PE film (UV-PE, Plastika Kritis S.A., Heraclion, Crete, Greece).Both films had 180 μm thickness and equal amounts of infrared, diffusion and ethyl-vinyl-acetate additives but had different UV-absorbers content in the main PE master batch formation, which resulted in differences in UV radiation transmissivity. The tomato crop (Lycopersicon esculentum, cv.Belladonna) was transplanted on 22/02/2003 and 25/02/2004, at the stage of 5-6 true leaves in bags filled with perlite at a density of 2.4 plants m -2 .Fertigation was automatically controlled by a computer with set points for electrical conductivity of 2.1 dS m -1 and pH of 5.6.Plants were pruned to one stem, topped after the 7 th truss and treated equally with fungicides [chlorothalonil (72-75% wettable powder, wettable granules, concentrating liquid suspension)] and miticides [clotentezine (50% concentrating liquid suspension) and propargite (30% wettable powder) for Tetranychus eggs and adults respectively] application when deemed necessary.A beehive of bumblebees Bombus terrestris (L.), was installed in each greenhouse to facilitate pollination.Plants in each greenhouse were divided into four blocks having 90 plants each. | 4 |
85002311 | Measurements The following climatic data were recorded outside (on a meteorological mast) and inside (centre) of each greenhouse using sensors calibrated before the experimental period: air temperature, relative humidity, global solar radiation (model Middleton EP08-E, Brunswick Victoria, AUS), photosynthetically active radiation (model LI-190SA; Lincoln, NE, USA), UV-B radiation (290-315 nm, model SKU 430, Sky instruments LTD, UK) and UV-A radiation (315-380 nm, model SKU 420, Sky instruments LTD, UK).Each sensor was scanned every 30 s and averaged every 10 min using a Delta-T data logger system (model DL3000, Delta-T devices, Cambridge, UK). PE film spectral transmittance measurements were made in the laboratory on three samples per PE film taken before their installation in the greenhouses using a LI-COR portable spectroradiometer (model LI-1800, LI-COR, Lincoln, NE, USA) equipped with a 10 W glass halogen lamp and an external integrating sphere (model LI-1800-12S, LI-COR, Lincoln, NE, USA) (Kittas & Baille, 1998). Fruit harvesting took place twice a week, at the light red stage of maturity, according to the classification of Grierson & Kader (1986).Harvested fruit from 24 selected plants in each greenhouse were weighed, their dimensions were measured and the total production was calculated.Fruit were sorted into marketable and rejected production.The rejected production was due to (i) physiological problems, including small fruit (weight < 100 g), fruit with defects, breaks, scars, blossomend rot and other physiological disorders; and (ii) insects damage (was assessed in the scale 1 -5: 1 = none, 2 = slight, 3 = moderate, 4 = severe, 5 = extreme).The most prevalent insect causing fruit injuries was thrips (Frankliniella occidentalis).Thrips number was monitored every week by means of 12 blue sticky HORIVER ® traps (25 × 10 cm) and measurements on ten tomato plants (top, middle, bottom leaves) in each greenhouse (Vatsanidou et al., 2009). Two measuring procedures were used for fruit skin colour measurements.The first one was applied both years (2003,2004) recording colour of all harvested mature fruit.The second one, applied only during 2004 experimental period, included measurement of fruit on the vein for colour evolution evaluation through the six maturity stages (green, breaker, turning, pink, light red and red).Forty two non-shaded, randomly selected fruit of the same truss with uniform shape and size were labelled in each greenhouse and their colour was measured every 1 to 3 days, according to severity of colour change, from green maturity stage until fully ripe fruit.Colour was measured by a Miniscan TM XE Plus (Hun-terLab, Hunter Associates Lab, Inc., Reston, VA, USA) tristimulus colour analyzer and colour around fruit equatorial region was recorded (6 measurements per fruit).Measurements were reported in the L*, a*, b* system [CIELAB, L* varies between light (L* = 100) and dark (L* = 0), a* varies between green (a* = -50) and red (a* = 50), and b* varies between yellow (b* = 50) and blue (b* = -50) colour].Chroma and hue (h°) values were also calculated (McGuire, 1992). Fresh fruit were macerated in a blender for titratable acidity, total soluble solids, ascorbic acid and lycopene determinations.Total soluble solids (TSS) content was measured using a refractometer (model PR-1, Atago, Tokyo, Japan).Titratable acidity was measured by titra-tion with 0.1 N NaOH to pH 8.2 and results were expressed as % citric acid.Ascorbic acid was extracted in 1% oxalic acid and measured with reflectoquant ascorbic acid test strips (RQflex 10 Reflectoquant, Merck KGaA, Darmstadt, Germany) in a reflectometer (model 116970 Reflectometer Merck KGaA, Darmstadt, Germany).Lycopene was extracted by homogenizing 1 g sample with 25 mL of acetone in a centrifuge tube shaken in the dark.Absorbance at 503 nm was measured by means of a spectrophotometer and lycopene content was calculated using the molecular extinction coefficient of 17.2 • 10 4 L mol -1 cm -1 and expressed as mg per 100 g fruit weight (Mencarelli & Saltveit, 1988). | 5 |
85002311 | Greenhouse microclimate The average transmission coefficients for PAR, UV-A and UV-B radiation, as calculated by the ratio of inside to outside measured value of each parameter during 2003 experimental period were 74.3%, 20.7% and 12.5% in the C-PE greenhouse and 75.5%, 0.4% and 1.2%, in the UV-PE covered greenhouse, respectively.The values changed during the replicate experimental period of 2004 to 73.0%, 28.7% and 26.7% in the C-PE greenhouse and to 72.7%, 0.8% and 1.3% in the UV-PE greenhouse.These results indicate that the UV radiation absorbing properties of the UV-PE film were maintained for two summer seasons after its placement in the greenhouse.In addition, measurements conducted in the laboratory concerning films' spectral transmittance revealed that both films had similar radiation properties in blue (400-500 nm) and green to red (500-700 nm) spectrum regions during both years (data not shown).Thus, any differences that may have emerged on crop yield and fruit quality characteristics could be ascribed to differences of the covering materials in UV-radiation transmittance.According to Krizek et al. (2005) plant productivity of greenhouse crops is greatly influenced by the amount of UV radiation, photosynthetically active radiation (PAR) and IR transmitted through the covering material of these structures which is not the case in our tested films since their transmittance in blue, green to red and PAR radiation regions was the same. Air temperature and vapour pressure deficit (VPD) data during 2003 experimental period are presented in Table 1.Temperature and VPD values followed a similar pattern during the experimental period in both greenhouses.Similar values were also found during 2004 replicate experimental period (data not shown). The UV-radiation energy flux corresponds to about 3.8% of the total solar radiation energy flux outside the greenhouse (Robaa, 2004).Considering that the films tested differ in UV transmission by about 28%, the difference in the incoming solar energy flux is expected to be about 1% (= 28% × 3.8%), which, | 7 |
85002311 | VPD i (kPa) UV-A (kJ m -2 day -1 ) Effects of UV-absorbing covers on tomato quality for an average temperature of 20°C, may induce a 0.2°C temperature difference between the two greenhouses. Consequently, the only difference between the environments of the two greenhouses could be considered the quality of light. | 8 |
85002311 | Fruit yield No significant differences (p ≥ 0.05) were found between the two greenhouses in total yield, fruit number, marketable mean fruit weight and non-marketable fruit production ought to physiological problems (meaning zipper, blossom end rot, cutface, sunscald, small size).Under the UV-PE greenhouse, a significant decrease of fruit with insect injuries was observed during both years (Table 2).This could be explained by the significantly lower number of thrips observed in the UV-PE greenhouse, as indicated by the significantly lower number of thrips caught in the sticky traps in the UV-PE greenhouse (Table 3).It has also been observed that under UV-absorbing films some crops such as tomato (González et al., 2004;Monci et al., 2004), eggplant (Kittas et al., 2006) and lettuce (Nigel et al., 2005;Diaz et al., 2006) show better performance and yield. The majority of the reports that concern the effect of UV-absorbing films on crop, focus on pest and disease control.They measure the efficiency of UVabsorbing films on insect population and its impact on marketable yield, although Antignus et al. (1996) mention that the effect of UV-absorbing films on crop yield due to a decrease of virus transmission may be higher than the effect on yield due to reduced insect population.Park et al. (2007) found that the number of marketable fruit decreased as thrips density increased and they also suggest that thrips fruit damage should not be evaluated in terms of yield loss, but in terms of the percentage of damaged fruit.They stated that thrips caused direct damage to fruit by feeding on and laying eggs in the developing fruit causing darkness and malformation.Similar impacts on crop yield were also observed in the present study.Rheinländer et al. (2006) stated that between thirteen species of insects and mites found on tamarillo leaves and fruit, most of these were not likely to cause any damage on fruit (e.g.spiders, lacewings ladybirds and beetles) and declared that thrips was the only insect which could cause such scarring. The cosmetic scars that were observed in the harvested fruits of the present study were similar to those presented by Rheinländer et al. (2006), according to which thrips was the major cause for fruit damages.It was found that, compared to the C-PE greenhouse, thrips' population was 70% lower in the UV-PE than in the C-PE greenhouse, during the total experimental period and that the percentage of harvested fruit affected by thrips (injury score > 2), varied from 5% to 25% during both experimental periods. | 9 |
85002311 | Fruit quality Tomato specific fruit weight (g mL -1 ) was similar in the two greenhouses ranging from 1.08 to 1.16 and from 0.93 to 0.95 for 2003 and 2004 experimental periods, respectively.Fruit shape parameters, which are components of fruit quality according to the European Commission (1983), were similar in both greenhouses (Table 4). Table 2. Marketable yield, fruit number per greenhouse area, fruit weight and rejected production due to physiological problems such as zipper, blossom end rot, cutface, sunscald, small size, and insect damage in the tomato crop grown under the greenhouse covered by the UV-absorbing (UV-PE) and the common polyethylene (C-PE) film during the two experimental periods.Values [mean ± SE (standard error)] followed by different letters within year are significantly different (p ≤ 0.05) | 10 |
85002311 | Year Greenhouse Total yield (kg m -2 ) In fruit shape formation, pollinators play a major role (Al-Attal et al., 2003).As fruit shape parameters did not differ among UV environments of the present work it could be assumed that bumblebees' activity was not affected by the UV-absorbing film. Total soluble solids (TSS), ascorbic acid, lycopene content, pH and titratable acidity values were similar under both PE-films (Table 4).TSS were increased with time as truss number also increased under both greenhouses (Fig. 1).Similar results have been also reported by Bertin et al. (2000)The influence of low UV-B radiation levels on ascorbic acid, lycopene (Giuntini et al., 2005) and TSS content (Krizek et al., 2006) depends on tomato genotype and accordingly, the results of the present study may be valid only for the tomato cultivar studied.The non significant differences in fruit ascorbic acid and TSS content that was found in the present study may indicate a neutral reaction to UV radiation reduction of the specific cultivar tested. Colour values (L*, hue, chroma) of harvested fruit were similar under both greenhouses and experimental periods (Fig. 2A, B and C, data for 2004 are not shown).The fruit colour is mainly attributed to the β-carotene and lycopene content (Grierson & Kader, 1986).Since lycopene content was similar under both greenhouses (Table 4) it could be assumed that the observed colour differences are attributed to the differences in β-carotene content.Hue colour parameter could be used as an objective colour index for vine ripened tomato fruit (Lopez-Camelo & Gomez, 2004).In the present work, hue values did not show any difference (Figs.2B, 2E) between the two greenhouses and accordingly, it could be concluded that tomatoes produced under the UV-PE greenhouse are not inferior of those produced under the C-PE covered greenhouse.Lastly, on the vein colour evolution evaluation through the six maturity stages (green, breaker, turning, pink, light red and red) showed that fruit under the UV-PE greenhouse had significantly higher chroma values than under the C-PE during light red and red maturity stages (Fig. 2F).These differences could be attributed to differences in synthesis rate of others than lycopene pigments. It could be concluded that use of UV-absorbing greenhouse covering films that modify the UV radiation light environment leads to reduction of number of insect injured Effects of UV-absorbing covers on tomato quality fruit and to similar or higher marketable yield, while fruit quality characteristics (size, shape), nutritional value (ascorbic acid and lycopene) and organoleptic quality (pH, titratable acidity, total soluble solids) are not affected.Therefore, UV-absorbing films can be considered as an effective practice in tomato crop protection from insect, without negative effects on fruit quality attributes. | 11 |
17069677 | Introduction In connection with ongoing synthetic work, we needed access to good acylating reagents based on isonicotinic and picolinic acids. Acylations with isonicotinoyl and picolinoyl chlorides were found to be troublesome, because the acid chlorides are only prepared or available as the corresponding hydrochlorides, which are only sparingly soluble in inert solvents. A further complication was, that upon reaction with polyamines such as poly(propyleneimine) dendrimers incomplete reactions occurred due to extensive salt formation. Therefore we turned our attention to the so called active esters [1]. | 2 |
17069677 | Results and Discussion Searching the literature we found references to the p-nitrophenyl esters of isonicotinic [2,3] and picolinic acid [2,3,4], which have been used for the synthesis of potent antagonists of the luteinizing hormone-releasing hormone (LHRH) [4,5]. The only other ester reported was the pentachlorophenyl ester of isonicotinic acid [6], however in the latter case, no experimental details were given. All the procedures were based on the DCC coupling of the acids with the corresponding phenol, however especially in the case of picolinic acid the coupling reaction was hampered by the well known rearrangement of the intermediate O-acylureas to N-acylureas [2]. This problem could be solved by performing the coupling reaction in CH 2 Cl 2 , but again no experimental details were given [2]. We were primarily interested in obtaining the more reactive [1] N-hydroxysuccinimidyl and pentafluorophenyl esters, and since DCC-coupling mainly gave the corresponding N-acyl-N,N'-dicyclohexylureas, the present method was developed. Reaction of the corresponding pyridinecarboxylic acid with SOCl 2 catalyzed by DMF [7] at room temperature gives the acid chlorides as their hydrochlorides. These were reacted with 4-nitrophenol, pentafluorphenol and N-hydroxysuccinimide in THF with triethylamine as base to give the corresponding active esters. The compounds prepared are shown Table 1. | 3 |
17069677 | Experimental General 1 H-and 13 C-NMR spectra were obtained using a Varian Gemini 300 NMR or a Varian Unity 400 NMR. Mass spectra were obtained using a Jeol JMS-HX 110 A Tandem Mass Spectrometer. IRspectra were recorded on a Perkin Elmer 1760 X. All melting points are uncorrected. The elemental analyses were performed by Mrs. Karin Linthoe, Department of Organic Chemistry, University of Copenhagen. All chemicals were used as received. | 5 |
17069677 | Isonicotinoylchloride hydrochloride Thionylchloride (60 mL) was added carefully to a stirred mixture of isonicotinic acid (24.6 g; 0.2 mol) and DMF (1 mL). A lively gas evolution started, and after 30 minutes all of the acid had gone into solution and the temperature had risen to about 40°C. Excess thionyl chloride was removed in vacuo, and diethyl ether (200 mL) was stirred into the residue. The crude product was filtered, washed with diethyl ether and dried in vacuo at 40°C. Yield: 35.0 g (98%) of white crystals sufficiently pure for the preparation of the activated esters. | 6 |
17069677 | Isonicotinic acid pentafluorophenyl ester To a stirred suspension of isonicotinoylchloride hydrochloride (8.9 g; 0.05 mol) and pentafluorophenol (9.2 g; 0.05 mol) in THF (100 mL) was added triethylamine (20 mL; 0.14 mol) over 10 minutes. The suspension was stirred at room temperature for 12 hrs, filtered and concentrated in vacuo. The residue was dissolved in hexane (300 mL), treated with activated carbon and filtered. The hexane was removed to give the pentafluorophenyl ester as a slightly brownish oil, which crystallized to give a creme colored solid melting 52-54°C. Yield: 14.0 g (97%); 1 | 7 |
104388387 | Introduction Meat is a substance that is rich in protein and lipid, and is rather susceptible to oxidation. During events such as meat processing (i.e., storing, cooking and drying), protein oxidation can occur frequently. As a result, the quality of meat products is reduced through phenomena such as the loss of juiciness and reduced cooking yield. [1,2] Therefore, it is of great importance to control protein oxidation and reduce lipid oxidation in meat products. In the past, synthetic antioxidants have traditionally been used to prevent the oxidation of proteins and lipids in food products. However, recent consumer concerns have been focused on the potential of synthetic antioxidants in being carcinogenic. As a result, interest has developed in the use of natural antioxidants in food products and garnered attention from the scientific community. Among various natural antioxidants, plant-derived antioxidants have been widely used in recent years. [3,4] Antioxidants found in plant extracts are primarily phenolic compounds. These extracts provide promising antioxidant properties through their capacity to regulate intra-cellular hydrogen supplies and metal-ion chelation potentials. [5] Polyphenols have widely been used to inhibit the oxidant modification of meat products. However, while the potential of polyphenols to act as antioxidants in meat products has proven to be effective in delaying lipid oxidation, the same is not true concerning protein oxidation. In some studies, phenolic acids have been found to accelerate carbonylation and sulfhydryl loss. For example, green tea extracts increased thiol loss and protein polymerization in Bologna-type sausages prepared from UV-irradiated pork. [6] Furthermore, beef patties treated with polyphenol-rich willowherb extracts resulted in reduced lipid oxidation, but accelerated protein carbonylation and discoloration. [7] Rosemary and oregano essential oils were found to retard thiol loss, whereas garlic essential oil promoted thiol loss and myosin cross-linking formation in pork patties during chill storage. [8] In protein-rich foods, phenolic substances can interact with proteins through covalent bonds and non-covalent bonds, thereby altering the structure of proteins, leading to functional changes. [9] The oxidation of processed muscle foods was inevitable due to loss of tissue integrity during meat processing and through endogenous prooxidants in fresh muscles. When these phenolic compounds are oxidized, they produce quinones when added to the meat product formulations. Quinones may be associated with the oxidation of proteins during meat processing or cooking. [10] N-nitrosamines (NAs) are potentially carcinogenic, mutagenic and teratogenic effects to various animals and humans. [11] There are three primary ways of human interaction with NAs: foods, other environmental sources and internal endogenous synthesis. NAs are formed from primary, secondary amines and nitrosating agents in foods such as fish and meat. Therefore, it is essential to reduce or completely inhibit the formation of NAs. The degradation and oxidation of proteins into small molecules may be the reason for the formation of NAs. [12,13] The chemical changes (oxidation, nitrosation and proteolysis) of meat proteins during digestion lead to a decrease in their nutritional value. [14] To clarify the mechanisms of NAs formations, the model system has commonly been used to investigate the different processing parameters or precursors. Although meat proteins are an important reactant in NAs formation, the potential effects of protein oxidation on NAs formation has rarely been reported. Although there have been some studies on the use of phenolic compounds to inhibit MP oxidation, few reports have studied the effects of phenolic compounds on NAs in the oxidation systems. In general, plant polyphenols include catechins, epicatechin, procyanidins, chlorogenic acid and caffeic acid. Epicatechin alias: 2-(3,4-dihydroxyphenyl)-2,3,4-trihydro-3,5,7-trihydroxychromene, has two hydroxyl groups at the ortho position of the aromatic ring. Epicatechin is a phenolic compound with the potential to protect products against oxidative/nitrative stress. The purpose of this investigation was to study the protective effects of epicatechin on the protein structure characteristics, water distribution of protein gel, and NAs formation. | 2 |
104388387 | Materials Fresh pork meat from the Longissimus muscle of pig carcasses (24-hours postmortem) was bought from a local supermarket (Suguo, Nanjing, Jiangsu, China). Individual loin chops (weighing~100 g) were packaged and stored in a freezer (−18ºC) until use within one month. In the present study, the chemicals were of reagent grade, and purchased from Aladdin Industrial Corp. or Sigma-Aldrich Co. | 3 |
104388387 | MP extraction and sample preparation MP extraction: MP was prepared according to methods of Park & Xiong [15] and Feng et al. [16] with some modifications. About 400 g of meat was chopped into small sections. The isolation buffer containing 20 mM of sodium phosphate, 0.1 M of NaCl, 2 mM of MgCl 2 , and 2 mM of EGTA at pH 7.0 was used for the MP extraction. Then 50 g of meat and 200 g of isolation buffer were homogenized using an Ultra Turrax dispersing instrument (T18-Digital, IKA, Staufen, Germany) in an ice bath. After filtration through four layers of gauze, the homogenate was spun twice at 2000 × g for 15 min at 4°C. Subsequently, the pellets were washed twice with 4 L of a 0.1 M NaCl solution. Afterwards, the collected pellets were washed again with 4 L of 20 mM PBS (pH 7.0). The concentration of the obtained protein was measured by the Biuret method. Oxidative treatments with epicatechin: MP suspensions were prepared with 15 mM piperazine-N,N´bis (2-ethanesulfonic acid) (PIPES) buffer containing 0.6 M of NaCl at pH 6.25. Six different reaction mixtures (protein concentration, 40 mg/mL) were prepared with epicatechin (0, 0.1, 0.2, 0.5, 1 and 2 mM). Samples with or without epicatechin were oxidized at 4ºC for 12 hours using a hydroxyl radical generation system (10 μM of FeCl 3 , 100 μM of ascorbic acid, and 1 mM of H 2 O 2 ). [17] Oxidation was stopped by adding a Trolox C/EDTA mixture (1 mM). A nonoxidized and epicatechin-free MP suspension was used as the control. | 4 |
104388387 | Changes of protein side chain structure Sample carbonyl contents were analyzed using the 2,4-dinitrophenylhydrazine (DNPH) colorimetric method. [18] Briefly, the carbonyl groups were reacted with DNPH to produce protein hydrazones in acidic conditions. The absorbance was measured at 370 nm with an absorption coefficient of 22,000 M −1 cm −1 in order to calculate the carbonyl content. Total sulfydryl content and free sulfydryl content were measured using absorbance at 412 nm with 5,5ʹ -dithio-bis (2-nitrobenzoic acid) (DTNB) used as an indicator. [19] The total sulfhydryl group was measured with a solution containing urea (8 M urea, 0.086 M Tris, 0.09 M glycine, 4 mM EDTA, pH 8.0), and the free sulfhydryl group was determined using a solution without urea(0.086 M Tris, 0.09 M glycine, 4 mM EDTA, pH 8.0). A molar extinction coefficient of 13,600 M −1 cm −1 was used to calculate sulfydryl content. Surface hydrophobicity was measured using data obtained from absorbance at 595 nm with the bromophenol blue (BPB) binding method. [20] Tryptophan fluorescence was determined using an F-4600 fluorescence spectrophotometer (Hitachi, Japan). MP suspensions (0.1 mg/mL) were excited at 283 nm, with the emission spectra recorded from 300 to 400 nm. | 5 |
104388387 | Gelation properties MP suspensions (5 g, 40 mg/mL in 15 mM PIPES) were transferred into glass vials. These were covered with aluminum foil, heated in a water bath from 20ºC to 80ºC at 1ºC/min increments, and were then maintained at 80ºC for 20 minutes. After heating, the formed gels were immediately chilled in an ice bath for 30 minutes and then the juice was removed from the surface of the gels. Cooking yield was calculated using the following formula, in which W gel and W sol are the weight of the gel and the original solution, respectively. The water holding capacity (WHC) of the samples was measured using the method described by Kocher and Foegeding. [21] Exactly 5 g of gel was placed in a centrifuge tube and centrifuged at 10,000 × g for 10 minutes at 4ºC. Then, WHC was calculated as the percentage of the retained weight of a gel after centrifugation relative to its initial weight. Gel whiteness was determined using a CR-400 chroma meter (Konica Minolta, Osaka, Japan). Color analyses were performed using the CIE coordinates (L*, a*, and b*). Whiteness value was calculated as: Dynamic rheological testing was measured during the heat-induced gelation with a model AR1000 rheometer (TA Instruments, West Sussex, U.K.) in an oscillatory mode equipped with parallel plate geometry (40 mm diameter). Gelation was induced by heating the protein emulsion from 20 to 90°C at a rate of 2°C/min. Changes in the storage modulus (G') were monitored continuously. | 6 |
104388387 | NDEA in an oxidized protein solution The formation of NDEA was measured on according to the report with slight modifications. [13,24] MP suspensions (10 mg/mL), diethylamine (50 mM) and sodium nitrite (5 mM) were mixed into a 50 mM phosphate buffer (pH 3.0, a simulated gastric acid system) (all concentration was final). Two series reactions were carried out in stoppered conical flasks. The reactions of one group were set for 4 h at 37°C, while the other group was set for 1 h at 80°C. After the reaction, the mixtures were mixed with 5 mM of sulfanilic acid to stop the reaction, and centrifuged at 3,000 × g for 5 min at 4°C . The clear liquid on the upper section of the tube was immediately subjected to HPLC analysis for nitrosamines, targeting NDEA. An HPLC unit (Agilent 1260, CA, USA) equipped with an Agilent UV detector was employed. Liquid chromatography separation was carried out on a ZORBAX SB-C18 column (150 cm × 4.6 mm, 5 μm) and peaks were detected at 230 nm. An elution program was used with a mixture of 35% methanol and 65% water at a flow rate of 1 mL per minute. A linear relationship was obtained over a range of the concentration between 0.1 and 10.0 μg/mL. The obtained correlation coefficients (R 2 ) were greater than 0.99. | 7 |
104388387 | Statistical analyses The entire experiment was replicated three times on different occasions. Statistical treatments were performed with SPSS version 18.0 (SPSS Inc., Chicago, IL). One way analysis of variance (ANOVA) was applied to assess the significance by means of Duncan's multiple range tests. The statistical significance was set at p < 0.05. All results were calculated as the means and standard deviations. | 8 |
104388387 | Carbonyl content Carbonyl levels are a well-known index for the level of protein oxidation in meat products during processing. [2,25] The carbonyl content of the control MP was 1.08 nmol/mg protein (Table 1) which was close to the report of freshly prepared MP as described by Cao and Xiong. [26] Oxidation significantly increased the carbonyl content of samples (3.63 nmol/mg protein) when compared to the control MP (p < 0.05). The presence of epicatechin significantly inhibited the formation of the carbonyl, especially at a large epicatechin dose of 2 mM (1.14 nmol/mg protein), which was near to the control MP. Epicatechin was oxidized into a quinine derivative in this oxidation system. This study was in accordance with those previous reports in which phenolic compounds inhibited protein carbonyl content, such as quercetin [27] ，rosmarinic acid [28] and EGCG. [29,30] Total and free sulfydryl groups MP is rich in sulfydryl groups, which are susceptible to attack by reactive oxygen species and can then convert to intra-and intermolecular disulfide bond linkages. [10] As shown in Table 1, the total sulfydryl group content of control MP was 109.63 nmol/mg protein. About 6.6% total sulfydryl group (p > 0.05) was lost when MP samples were exposed to hydroxyl groups. Compared to the control MP, the total sulfydryl group contents were significantly lower in the absence of epicatechin. Furthermore, the total sulfydryl group levels exhibited an epicatechin dose dependent decrease. Compared to the control MP, about 44% total sulfydryl group (p < 0.05) was lost when MP samples were exposed to hydroxyl groups and 2 mM epicatechin. The free sulfydryl group levels in oxidized MP had the same transformation tendency as the total sulfydryl group levels. This could be explained by the formation of thiol-quinone adducts. These observed results are in accordance with previous reports. Cao & Xiong observed that chlorogenic acid had no protection on thiol groups, and high chlorogenic acid revealed the lowest sulfydryl content. [26] Surface hydrophobicity It is generally believed that the amount of protein binding BPB can be used as an estimator of protein hydrophobicity estimation. The surface hydrophobicity of the oxidized MP was significantly higher (p < 0.05) than that of the control ( Table 1). The surface hydrophobicity of the oxidized MP significantly decreased in the presence of EC (p < 0.05), especially in a large dose (2 mM). This decrease of surface hydrophobicity with increased epicatechin may be due to protein aggregation caused by the addition of epicatechin. The decrease was consistent with the change trend of carbonyl content. This study was consistent with other previous reports which indicate that phenolic compounds inhibit the surface hydrophobicity. [29] It is also shown that phenolic compounds can protect protein side-chain groups. | 9 |
104388387 | Intrinsic tryptophan fluorescence As shown in Figure 1, when compared with the control MP, the intensity of tryptophan fluorescence from oxidized MP was significantly decreased indicating that the protein was denatured. The inclusion of epicatechin promoted the loss of intrinsic fluorescence, especially at the concentration of 2 mM epicatechin. This was consistent with the change seen in surface hydrophobicity, indicating that oxidation leads to further expansion and possible interactions of protein side chains and phenolic compounds. The fluorescence characteristic of tryptophan was particularly sensitive to the polarity of tryptophan microenvironment. It was widely used as a measure index of protein tertiary structure. Similar results were obtained when binding chlorogenic acid to MP [26] or epigallocatechin (EGC) to β-lactoglobulin. [31] In the process of protein oxidation, non-covalent and covalent interactions involving proteins, as well as possible quinone-protein interactions, eventually lead to modifications of proteins in primary, secondary and tertiary structures. | 10 |
104388387 | Gel properties The cooking yield, WHC and whiteness of myofibrillar protein gels are summarized in Table 1. Cooking yield was slightly reduced when treated with epicatechin, but this had no significant effect on the cooking yield with or without epicatechin in the hydroxyl radical generating system (p > 0.05). The results of this study may be influenced by the amount of epicatechin addition. In the present study, the amount of epicatechin utilized was low. The WHC of the MP gels increased significantly (p < 0.05) as the epicatechin concentration increased from 0 to 2 mM. This indicates that epicatechin can increase the WHC of the gel, allowing it to be used in meat processing for improving the quality of meat products. The addition of epicatechin at 0.1 mM had no effect on gel whiteness (p > 0.05), while epicatechin from 0.2 to 2 mM reduced gel whiteness (p < 0.05). The reduction in whiteness was possibly due to the chelation of ferric iron and epicatechin oxidation. The storage modulus (G') are used to represent the amount of recoverable energy stored in the elastic gel ( Figure 2). The oxidized MP had a final G' significantly higher than the control, suggesting that oxidation promoted protein interactions. The G' of the MP emulsion gel treated with 2 mM epicatechin was higher than 0 mM epicatechin, suggesting that epicatechin did not prevent the crosslinking induced by heating under oxidative stress. This was consistent with previous research on MP treated with EGCG. [29] The LF-NMR technique is an alternative method for assessing water distribution and mobility during protein gel formation. Figure 3 shows the T 2 relaxation time distribution of MP gels. The calculated relaxation times, T 21 , T 22 and T 23 , correspond to the combined water, immobilized water, and free water in the gel, respectively. [32] Table 2 shows the effect of epicatechin induced modification on the proportions of P 21 , P 22 and P 23 of MP gels. The proportions of P 21 were not significantly (p > 0.05) affected by oxidation and epicatechin. The oxidation treatment resulted in a lower P 22 when compared with the control MP gels (p < 0.05). P 22 was slightly increased with increasing epicatechin concentration from 0 to 2 mM, corresponding to the results of WHC in this study. Tea polyphenols may increase the exposure of sensitive side chain groups and enhance the reaction between proteins and phenolic compounds. This hastened the formation of protein gelation, which is retained in the MP network. [33] For P 23 , the peak area was increased significantly (p < 0.05) by oxidation. The peak area was decreased with increasing epicatechin concentration from 0 to 2 mM (p > 0.05), thus indicating that phenolic compounds can protect the oxidized protein. These findings suggest that oxidation decreased the presence of immobilized water in the gel，while phenolic compounds have a tendency to increase the occurrence of immobilized water. In addition, compared to the oxidized MP, gels with high epicatechin had much higher immobilized water content. This proved that phenolic compounds can be good antioxidants and inhibit protein oxidation, reduce the loss of WHC, and improve the hydration of the proteins. [34] NDEA analyses Previous studies have shown that NAs can be formed in cured meat and fish: N-nitrosodimethylamine (NDMA), NDEA and the other NAs. [12,13,35] According to the classification of carcinogenic compounds, NDMA and NDEA fit in the group of probable carcinogens, whereas other NAs fall into the group of possible carcinogens. [36] Previous studies have also shown that only the level of NDEA was high in most samples, which is easy to measure by HPLC. [13,24] Therefore, NDEA was specifically measured in the present study. The representative chromatogram of NDEA by HPLC was shown in Figure 4. NDEA can achieve a good symmetrical peak shape under test conditions with good accuracy and precision. The retention time of standard and sample was the same in this study. The levels of NDEA in the stimulated nitrite curing solution are shown in Figure 5. The content of NDEA in the solution for 4 h at 37°C increased when the epicatechin content increased from 0 to 1 mM, attaining the maximum quantity of NDEA (4.88 µg/mL). However, when epicatechin content was 2 mM, the amount of NDEA production decreased to zero. The content of NDEA in the solution for 1 h at 80°C solution increased when the epicatechin content increased from 0 to 0.5 mM, attaining the maximum quantity of NDEA (10.22 µg/mL). However, when epicatechin content was at 1 or 2 mM, the amount of NDEA production decreased near to zero. Overall, the amount of NDEA formation was first increased to a certain amount, and subsequently rapidly decreased. The formation trend of NDEA was consistent under different temperature treatments. This study also showed that epicatechin concentration higher than 2 mM can completely inhibit the formation of nitrosamines. Choi et al. reported that green tea had a strong inhibitory effect on the nitrosation of secondary amines under gastric conditions. [37] However, since they used green tea at high concentrations, and not at low concentrations, they were not able to observe the promoting effects of green tea on the formation of NAs. Other studies reported both the promoting and inhibiting effects of green tea on NAs formation in vitro, which was similar to that in the present study. [38] From these results, we considered that the promoting and inhibitory effects of epicatechin on the information NDEA might depend on the concentration of epicatechin and nitrite. Furthermore, Nakamura and Kawabata also studied that the nitrosation reaction could be inhibited by other polyphenols, such as flavonols, flavones and isoflavones. [39] Masuda also investigated the effects of eight chemicals in catechins on the formation of nitrosomorpholine. Resorcinol and phloroglucinol, which have an A-ring model structure, accelerated the formation of nitrosomorpholine at a low concentration, and inhibited it at a high concentration. [38] A conceivable mechanism was for the catalysis of nitrosation by some of phenolic conpounds. Nitroso derivatives may be formed by further reaction with the nitrite to generate a more powerful nitrosating agent, which could be a nitrosoquinone oxime derivative. Its reaction with the nitrosatable substrate produces the nitroso compounds. This mechanism indicates that increasing amounts of catalytically active phenolic compounds lead to higher concentrations of nitroso intermediates. This mechanism could explain the optimum ratio for nitrite to phenolic compound. Accordingly, a large excess of phenolic compounds would inhibit nitrosation, because the nitrosating agent would be completely used up in forming the catalyst agent and none would be left to continue the catalytic reaction. Although we confirmed that the A-ring structure in catechins affected the formation of NAs, the mechanisms have yet to be clearly clarified. In the present study, the heating temperature at 37°C was representative of gastrointestinal temperature. Meanwhile, the heating temperature at 80°C was representative of the processing for most instant meat products. However, further studies are needed to determine whether high temperatures (100 degrees or higher) could increase the contents of NAs or form other types of NAs. | 11 |
104388387 | Correlation coefficients between NDEA and protein oxidation variables The correlation coefficients between NDEA, protein oxidation variables and gel properties are shown in Table 3. NDEA was significantly correlated with free sulfhydryl content, which is consistent with the results reported by Sun. [40] In addition, carbonyl production or total sulfhydryl reduction was significantly correlated (p < 0.01 or p < 0.05) to that of surface hydrophobicity, suggesting that MP fraction oxidation processes might affect each other. WHC and whiteness were extremely and significantly correlated with free and total sulfhydryl content (p < 0.01), suggesting that protein oxidation affects gel properties. Overall, the significant correlation between the content of NDEA and protein oxidation systems when reacted with nitrite suggests that the oxidative formation of carbonyls and oxidative breakage of sulfhydryls with possible deamination contributed to the production of the secondary amine compounds in the manufacture of cured meat. | 12 |
54598076 | Chromium compounds are widely used in modern industry. Many of these compounds are dumped into the surrounding environment. Membrane technology is more efficient and effective than conventional methods for waste treatment. The research objective was to make a membrane separation process that can be applied to Cr(VI). Membranes were made from chitosan and silica rice husks. Variations of chitosan and silica rice husk used (g) are 2:1 (A1), 2:2 (A2), 3:1 (B1), and 3:2 (B2). The membrane was made by using an inverted phase technique. Results of SEM characterization of membranes showed that B2 has the largest pores at 2.58 μm. The FTIR characterization results indicate the presence of crosslinking between chitosan with silica rice husk with the appearance of Si-O adsorption band at wavelength 1122980/cm. A1 membrane, with the smallest pore size has the greatest rejection value towards Cr(VI) which is 70%. The result of this research showed that the composite membrane of silica rice husk was effective enough to adsorb metal Cr(VI) with an average adsorption capacity of 1665.85 mg/g. | 1 |
54598076 | Introduction The increase in industrial activity in Indonesia has had an effect on increasing environmental pollution.Pollution of water, air, soil and the disposal of hazardous and toxic waste (B3) is a problem that must be faced by communities living around the industrial area.Heavy metals, a type of B3 waste, are toxic and carcinogenic [1].Metal Cr(VI) is a heavy metal that is commonly found in electroplating industrial waste and is hazardous to health and the environment. Many methods have been used to process waste metal Cr(VI) including adsorption methods such as chromium with activated biomass sludge as an adsorbent [2], reduction methods with the compound KI as a reductor of Cr(VI) [3] and adsorption with straw [4].However, none of these waste treatment methods are effective in treating wastewater.The method now widely used to treat wastewater is membrane technology because the process is very simple, energy efficient, retains the material and does not use additional chemicals [5].In this study, composite membranes made of chitosan are mixed with silica rice husk. Rice husk is an abundant material because Indonesia is a country that produces rice husks.The rice husks contain silica.Based on research conducted, the content of silica (SiO 2 ) in the rice husk is quite high, ranging from 87-90% [6]. Chitosan is a polymer that has been widely used as a membrane material.Chitosan has the ability to adsorb metals by forming complexes with metals so chitosan can be used to treat waste metal [7].Chitosan membrane has a dense structure so it has very small porosity.For that reason chitosan is combined with silica to form pores that are more effective in screening waste.Particles of silica are ideal porogens for producing porous chitosan membranes with controlled porosity and good mechanic properties [8]. The purpose of this research was to make membrane filtration from chitosan composited with silica rice husks.Furthermore, the membrane is tested for its ability to adsorb metal Cr(VI) from artificial waste. | 2 |
54598076 | Methods The main materials used in this study were rice husk and chitosan.Rice husk is taken from the rice mills around IPB at Darmaga campus.Chitosan was purchased from the Fisheries Faculty of the Department of Technology, IPB, with 74.25% degree of deacetylation. Making silica rice husk was conducted in three stages i.e. drying, incinerating and acidification Pre-dried rice husks were washed with distilled water and then dried at 190 o C for 1 h in a furnace.Then the husks were incinerated at a temperature of 300 o C for 30 minutes, and 600 o C for 1 h.Once charcoal had formed it was heated again at a temperature of 600 o C for 1 h to become ash.The next process is acidification with HCl (37%) and more heating at a temperature of 1000 o C for 6 hours [9]. Preparation of composite membranes.The inverse phase technique was used.Chitosan was dissolved in 50 ml of 2% acetic acid solution and sonicated for 1 h.Then, the silica particles were gradually added to the chitosan.The solution was further sonicated for 1 h to make a homogeneous solution.Sonication was performed at a frequency of 42 kHz with a Bronson 2510 which breaks down the molecules so that they dissolve faster.The solution was then filtered, then shaped in the membrane mold and dried at 50 o C for 12 h in an incubator.After drying, the membrane was soaked in a solution of NaOH (5%).Membranes were further heated for 2 h at a temperature of 80 o C to remove silica and produce a porous chitosan membrane.The membrane was washed again with distilled water to remove residual NaOH.The modification made from previous studies [9][10] was the use of chitosan and silica rice husk mass composition.Variations in composition were performed to make membranes with the best pores to filter waste.In making this membrane the various mass compositions (g) of chitosan and silica rice husk used are: 2:1 (A1), 2:2 (A2), 3:1 (B1) and 3:2 (B2). Test of flux and membrane rejection.Determining water flux and waste rejection is obtained by measuring the amount of permeate volume that passes through a unit of membrane surface per unit area per unit time.The waste used is artificial wastewater obtained by dissolving K 2 Cr 2 O 7 in distilled water with a concentration of 300 ppm.The rejection coefficient (R) can be calculated using the following equation [11]: where C f ,, C p (mg/L) showed the value of feed concentration and permeation. | 3 |
54598076 | Results and Discussion Characterization of silica rice husk using XRD and FTIR.Heat at a temperature of 1000 o C produces silica rice husk in the form of crystals.Figure 1 depicts two silica peaks (SiO 2 ) at an angle of 2θ at 22 o and 36 o with quite high intensity.Referring to the XRD analysis research by Handayani [9], peaks also appear with high intensity at 2θ at 22 o and 36 o .The degree of crystallinity formed was 75.98%.The type of crystal formed can be determined by calculating the parameters of the crystal lattice by a value of 2θ.Lattice parameters can be determined by determining the value of a, b, and c.The XRD results of silica rice husk in Figure 1 The IR spectra of silica rice husk in Figure 2 show the appearance of a sharp peak of Si-O functional group at wavelengths of around 1055/cm.Si-O functional group is a characteristic of the silica compound.Moreover, the groups of O-H, Si-C and Si-Cl also appear at wavelengths 3371/cm, 820/cm, and 471/cm respectively. Analysis of functional groups membrane.Functional groups that appear in membranes A1, A2, B1 and B2 have transmittance intensity similar to the sharp peaks in the adsorption band of each group function.Morphological analysis of membrane.The membrane formed is porous.The porous membrane is formed due to the influence of the silica composition.The pore shapes formed area symmetrical and the pore size is not homogeneous, see Figure 4. Pore size of the membrane that forms varies depending on the composition of chitosan and silica (Table 1).A2 membrane has a larger pore size than membrane A1 because A2 added as much as 2 grams of silica while A1 has only 1 gram of silica.Similarly, for the B membranes, B1 has bigger sized pores compared to B2 which as more silica than B1.So the addition of silica will increase thepore size of the membrane formed.The results are consistent with previous research by Liu et al. [10] that states that silica serves as a porogen, meaning the particles of silica form pores in the chitosan membrane.This research revealed that the mass ratio of silica/chitosan is 10:1 (g), the membrane pore size on average is 25-35 μm. Flux membrane.In Figure 5 it can be seen that in minute10 the flux sharply declined until minute 22.If screening is continued the flux values continue to fall until they almost reach zero.Decline in the flux value is due to membrane fouling.The direct effect of fouling causes a decrease in permeated flux, while the longterm effect can cause irreversible fouling of the membrane material and reduce its lifetime [12].In this condition the membrane begins to clog up, thus affecting the amount that permeates the membrane.Membrane rejection.In the A1 membrane, as can be seen in Figure 6, the rejection value does not vary significantly from the screening waste process.The average value of membrane rejection for A1 is 70%. The average concentration of the final solution of Cr(VI) after being filtered by membrane A1 is 90.12 ppm.The average rejection value of membrane A2 is 66.18%, which is less than membrane A1.The final concentration of Cr(VI) after being filtered by membrane A2 is 101.47 ppm.The average rejection of B1 membrane is 67.55%.The average final concentration of Cr(VI) after being filtered by membrane B1 is 97.35 ppm, while after being filtered by membrane B2 it is 101.48 ppm. In Figure 6 it can also be seen that the chitosan membrane without silica is capable of holding metal Cr(VI) to a maximum of 41.37%.Chitosan can act as an adsorbent as it is able to bind the metal.However, the rejection value is still small because the chitosan membrane without silica is dense so its pores are very small compared to if it has the addition of silica.So, of the four membranes that have been tested, based on rejection ability the average is 70%, 66.18%, 67.55%, 55.32% and 30.50% for membranes A1, A2, B1, B2 and chitosan for separation within 22 minutes.A1 membrane with smaller pore sizes than membranes A2, B1 and B2 has the highest rejection value of metal Cr(VI) which is an average of 70%, meaning that only 30% of the metal membrane Cr(VI) can escape.This value is greater than the metal uptake of Cr(VI) with the ion exchange membrane cell method at the amount of 30% for 300 minutes [13].The results of research by Devaprasath et al. [14] using spicigeraprosopis plant leaves also has a Cr(VI) percentage adsorption of about 69.4%. The mechanism of metal adsorption that occurs between the membrane composite of chitosan with silica rice husk is supported by the nature of chitosan as a polycationic polymer.Chitosan is a chelating polymer t (minute) Flux (Lm-2 Hours -1 derived from natural ingredients so that chitosan is able to bind metals to form a metal-chitosan complex.Chitosan is an excellent ion chelating agent.Electrons of nitrogen contained in the amine group can form covalent bonds with transitory metal ions, including chromium.Chitosan acts as an electron pair donor in the transition of metal ions in the formation of a metalchitosan complex.While silica, in addition to forming pores in the membrane is also thought to act as a metal adsorbent of Cr(VI).This is evidenced by the increased rejection value of Cr(VI) on the chitosan membrane composited with silica compared with the chitosan membrane without the addition of silica rice husk. Average adsorption capacity of chitosan-silica rice husk composite membrane is 1665.85mg/g.When compared with the results of research by Vijaya et al. [15], the adsorption ability of chitosan with silica rice husk composite is greater than adsorbent chitosan coated with a commercial silica which is 294.1 mg/g.Kinetic adsorption.Determining the reaction rate (k) is calculated using the first-order and second-order kinetic model [16].According to Table 2 the adsorption of Cr(VI) with chitosan-silica rice husk membrane followed the second order because the value of R 2 is close to 1 (linear).The k values obtained in this study illustrate that the greater the reaction rate constant is the faster is the depletion of reactants. | 4 |
54598076 | Figure 5 . Figure 5. Flux Value of Membranes; A1 (■), A2 ( ), B1 (•), B2 (♦) The flux test results showed that membrane A1 produces a maximum flux value of about 50,000 Lm/m 2 hour in 300 ppm potassium dichromate (artificial waste).The value decreases within creasing flux time.At 10 minute the flux value is almost constant until 20 minute.This indicates clogging in the membrane called fouling.The maximum flux value of membrane A2 in artificial waste is around 60,000 Lm/m 2 hour.This flux value is higher than the A1 membrane.This indicates that membrane A2 has larger pore sizes.The A2 membrane has a chitosan:silica composition of 2:1 whereas the A1 membrane composition is 2:2.An increased amount of silica in the membrane causes larger pore size and consequently a greater flux value.Likemembrane A1, fouling of A2 membrane begins at minute10.Flux values of membranes B1 and B2 are not too different from membranes A1 and A2 as shown in Figure 3. Fouling also occurred in 10 minute marked by an increase of flux values that almost fell to zero at minute twenty.The average values of the artificial waste flux on membranes are in sequence 9,192.46Lm/m 2 hour; 8,788.74Lm/m 2 hour; 8,460.25 Lm/m 2 hour, and 2,403.77Lm/m 2 hour respectively for membranes A2, A1, B1 and B2.Membrane flux values are also influenced by the degree of membrane swelling.When the feed concentration permeates membrane A2 it opens pores thereby increasing pore size thus causing swelling. | 6 |
228832866 | : The self-condensation and cross-condensation reactions of ethanol and isoamyl alcohol are examined to better understand the potential routes to value-added byproducts from fuel ethanol production. Reactions have been carried out in both batch autoclave and continuous condensed-phase reactors using a lanthanum-promoted, alumina-supported nickel catalyst at near-critical condensed phase conditions. Analysis of multiple candidate kinetic models led to a Langmuir–Hinshelwood rate expression that is first-order in alcohol with water as the strongly adsorbed species. This model provides the best fit of data from both batch and continuous reactor experiments. Activation energies for primary condensation reactions increase as carbon chain lengths increase. Selectivities to higher alcohols of 94% and 87% for ethanol and isoamyl alcohol, respectively, were observed at di ff erent operating conditions. D.J.M. and I.N.; investigation, D.J.M. and I.N.; resources, D.J.M. and I.N.; data curation, D.J.M. and I.N.; writing—original draft preparation, D.J.M. and I.N.; writing—review and editing, D.J.M. and I.N.; and | 1 |
228832866 | Introduction The predominant route for the conversion of hexose sugars (sucrose, glucose, maltose, etc.) to ethanol (EtOH) with yeast of the Saccharomyces family is the Embden Meyerhof pathway [1,2]. In this pathway, the main product (~99%) is EtOH, with the byproducts formed typically referred to as "fusel" oils or alcohols [3,4]. Fusel alcohols consist primarily of isoamyl alcohol (IAOH) (3-methyl-1-butanol) along with n-propanol, isobutanol, and optically active amyl alcohol [5]. Whether formed as byproducts of EtOH fermentation [6] or from fermentation-derived amino acids [7], these compounds have essential applications as aroma and flavoring agents in the food and beverage industry [3,[8][9][10][11]. For instance, isoamyl alcohol is used to produce isoamyl acetate, widely used in the food industry for its banana flavor [12,13]. Further, mixtures of fusel alcohols can be used as solvents or cleaners, and as reagents with various organic acids to make mixed esters that have desirable properties as solvents or as fuel additives [14][15][16]. But presently, the most common end use of fusel alcohols involves blending with purified EtOH as fuel for internal combustion engines, where their high energy density and compatibility with hydrocarbons make them attractive additives [12,[17][18][19]. Fusel alcohols contain at least one hydrogen atom on the β-position of their carbon backbones, and so can participate in Guerbet condensation reactions, in which higher alcohols are formed via one of several postulated condensation mechanisms. Because they are produced along with EtOH and require substantial processing to be recovered in pure form, the opportunity exists to efficiently produce additional higher alcohols via reaction of partially purified fusel alcohols with EtOH and with each other. With current U.S. EtOH production at approximately 15 billion gallons annually and fusel oils constituting 0.3 wt% to 0.7 wt% (~200 million kg/y) of total alcohols produced, the potential exists to produce fusel oil-based chemicals priced at least an order of magnitude higher than ethanol. This impact would enhance profitability of existing EtOH production, could help facilitate more economical cellulosic-based EtOH production, and would contribute to reducing the selling price of other chemicals derived from EtOH [20][21][22]. Despite the comprehensive analysis of the Guerbet condensation of various alcohols via process, catalytic, thermodynamic, and mechanistic aspects [23][24][25][26][27][28], Guerbet reactions of fusel alcohols have been the subject of only a few studies. Matsu-ura et al. studied the conversion of fusel alcohols over a homogeneous Ir-based catalyst at 120 • C and atmospheric pressure and obtained yields of as high as 98% for the self-coupling of C 5 and C 6 alcohols, and 86% for the self-coupling of C 12 alcohol [29]. They also studied isoamyl alcohol as the reagent and were able to achieve 50% yield of C 10 alcohol at the same reaction conditions. Later, Busch et al. confirmed the feasibility of the synthesis of branched C 10 alcohols through the Guerbet reaction of isoamyl alcohols at 180 • C and elevated pressure ranges (1.4-4.6 bar) using a Pd/C-based homogeneous catalyst [30]. Unfortunately, no analytical data were reported. To date, no studies have been reported for Guerbet condensation reactions of fusel oil components with EtOH. We report here the reaction of isoamyl alcohol (IAOH), the primary constituent of fusel alcohols, with EtOH and with itself at condensed-phase conditions over supported nickel catalyst. Both batch reactions with different initial compositions and continuous, fixed bed reactions at different temperatures and reactor space velocities have been carried out. Higher alcohol yields and selectivities have been determined, and a kinetic model is developed to ascertain the relative rates of condensation of different alcohol species. | 2 |
228832866 | Batch Reactor Experiments Batch reactions were performed in a 300 mL Parr reactor (Model 4842, Parr Instruments, Chicago, IL, USA). The Parr reactor was equipped with an Omega 1/8" stainless steel Type J thermocouple to measure reaction temperature within ±1 • C. Calibrations for achieving this accuracy were conducted in previous work [32,33]. Reaction pressure was measured using an electronic pressure transducer (maximum pressure 200 atm) that was calibrated against a 100 atm mechanical gauge with increments of 0.7 atm. The mechanical stirrer was set at 1000 rpm during the reaction. After adding alcohols and catalyst, the reactor was sealed and purged with nitrogen at 1.0 atm overpressure. The reactions were carried out at autogenous pressure. An initial liquid sample was taken after nitrogen purging and before heating to the reaction temperature to verify initial composition. At the end of the reaction, the reactor was cooled and then depressurized. The total quantity of liquid products formed was taken as the sum of liquid sample masses collected and residual liquid in the reactor following depressurization. A sample of this residual liquid was weighed and then analyzed by gas chromatography as described below. The total quantity of gaseous products formed during reaction was determined by measuring the change in cooled reactor mass over the course of depressurization and collecting the gas in a sample bag. By determining the volume of gas collected via water displacement, the average molecular weight of the gas product was determined. | 3 |
228832866 | Continuous Reactor Experiments A 1.91 cm external diameter (1.57 cm ID) by 76 cm length jacketed 316 Stainless Steel up-flow packed bed reactor was used for continuous experiments. Approximately 30 g of catalyst were placed in the reactor. The temperature profile during reaction was measured with a Type K thermocouple inside a 3 mm OD internal thermowell located on the center axis of the reactor. The reactor temperature was controlled by circulating silicon oil through the jacket using a Julabo (Model SE-6) heating circulator. A Tescom (Model 26-1764-24) back-pressure regulator was used to control the reactor pressure at 100 bar and reduce the effluent pressure to near atmospheric. To preheat the feed mixture to the reactor temperature, silicon carbide (SiC, 20-50 mesh) was placed upstream of the catalyst bed. Stainless steel rod fillers were also used before and after the reaction zone to reduce dead space in the reactor. A feed composition of 79 mol% EtOH and 21 mol% IAOH was used in continuous flow experiments. Reactor temperature was varied from 210 • C to 250 • C, and the liquid feed flow rate was varied from 0.5 mL/min to 1.3 mL/min, corresponding to a weight hourly space velocity (WHSV) of 0.8 h −1 to 2.1 h −1 or a superficial residence time (τ) of 0.96 to 0.25 m 3 reactor/(m 3 feed/h), respectively. Once steady state operation of the reactor was achieved, condensable liquid products were collected in an ice/water trap over a period of time ranging from 30 to 90 min depending on the feed rate. The liquid product collected was analyzed using gas chromatography as discussed in the following section. The gaseous products were collected in a gas bag located downstream of the ice/water trap and quantified by the measurement of effluent gas rate at several time points during the product collection period. | 4 |
228832866 | Analytical Methods The analytical methods and instruments used in this study are the same as those described in previous studies [22,[31][32][33]. Liquid product samples were diluted 10-fold in acetonitrile and analyzed using a Varian 450 gas chromatograph (GC) with a flame ionization detector. A 30 m SolGel-Wax column (0.53 mm ID, 1 mm film thickness) was used with the following temperature program: initial temperature 37 • C for 4 min; ramp at 10 • C/min to 90 • C, and hold at 90 • C for 3 min; ramp at 10 • C/min to 150 • C; ramp at 30 • C/min to 230 • C and hold for 2 min. Butyl hexanoate 1% solution was used as an internal standard in liquid product GC analyses. Multi-point calibration curves were used to determine the response factor of each known product. Unidentified liquid product peaks were quantified for carbon recovery calculations by using an average molecular weight and response factor based on values from adjacent known peaks in the chromatogram. The number of moles of gas formed in reaction was determined volumetrically as described above. From the average molecular weight of gas byproducts, which ranged from 18 to 22 g/mol in all experiments, it was assumed that on average one mole of carbon was present in each mole of gas formed. Selected gas samples were analyzed by gas chromatography, as presented in previous works [22,[31][32][33][34], to support this assumption. The typical composition of gas byproducts is shown in Figure S1a of Supporting Information. An in-house Excel spreadsheet was used to convert the species concentrations from GC analyses to EtOH and IAOH conversion, selectivity to each higher alcohol formed from a particular feed alcohol (mol feed alcohol to product/mol feed alcohol converted), overall selectivity to liquid byproducts (mol C in liquid byproducts/mol C in EtOH + IA converted), overall selectivity to gas byproducts (mol C in gas byproducts/mol C in EtOH + IA converted), and overall carbon recovery (mol C in reactor effluent/mol C in feed alcohols). Overall carbon recovery is the carbon balance that reflects uncertainty in experimental methods and analysis, and therefore exceeds 100% in some cases. Selectivity to liquid byproducts was normalized to make total product selectivity sum to 100% in cases where total carbon recovery exceeded 100%. Selectivity to liquid byproducts and gas byproducts is presented on a carbon basis based on both feed alcohols taken together, as it was not possible to distinguish between the two alcohols as the source of some liquid and gas byproducts in mixed alcohol feed experiments. To further characterize the product composition, Karl Fischer titration was carried out in triplicate to determine water content of each sample. This value was used as a check of the overall molar balances for the reaction; the quantity of water formed was usually 25-30% greater than that predicted by the extent of alcohol condensations. The excess water formation arises from side reactions to form gas and liquid byproducts. | 5 |
228832866 | Experimental Results Guerbet reactions with two alcohols lead to a significantly wider variety of product species than for a single alcohol. The key higher alcohol products of the mixed IAOH and EtOH experiments are shown on the right side of Figure 1; the alcohols responsible for forming the products are shown on the left side of Figure 1. byproducts is presented on a carbon basis based on both feed alcohols taken together, as it was not possible to distinguish between the two alcohols as the source of some liquid and gas byproducts in mixed alcohol feed experiments. To further characterize the product composition, Karl Fischer titration was carried out in triplicate to determine water content of each sample. This value was used as a check of the overall molar balances for the reaction; the quantity of water formed was usually 25-30% greater than that predicted by the extent of alcohol condensations. The excess water formation arises from side reactions to form gas and liquid byproducts. | 6 |
228832866 | Experimental Results Guerbet reactions with two alcohols lead to a significantly wider variety of product species than for a single alcohol. The key higher alcohol products of the mixed IAOH and EtOH experiments are shown on the right side of Figure 1; the alcohols responsible for forming the products are shown on the left side of Figure 1. In addition to desired higher alcohol products, liquid byproducts are formed at the reaction conditions examined. The typical composition of these liquid byproducts for experiments with pure EtOH and IAOH is given in Figure S1b,c of the Supporting Information. Additional peaks that likely represent liquid byproducts of reactions between EtOH and IAOH or their reaction intermediates were observed in chromatograms of liquid samples. No attempt was made to identify these byproducts of cross alcohol reactions, although they were included in the overall carbon balance for experiments by estimating the carbon number of each product based on its location in the chromatogram. | 7 |
228832866 | Continuous Experiments Condensed-phase continuous reactions were carried out at 100 bar over 8 wt% Ni/9 wt% La 2 O 3 /Al 2 O 3 catalyst with a feed composition of 79 mol% EtOH and 21 mol% IAOH. Results of continuous flow experiments are given in Table 2. Prior to these experiments, control studied were performed with the same feed composition and catalyst at ambient conditions and without any catalyst at reaction conditions to ensure that the system does not contain any leaks and the reactor material does not provide any reactivity to the feed material. Tables 1 and 2 show EtOH selectivity toward higher alcohols ranging from 70-85% through both self-condensation and cross-condensation reaction with IAOH. The conversion rate of IAOH is lower than that of EtOH; very little C 10 product, the direct condensation product of IAOH, is formed. Nearly all IAOH reaction to higher alcohols takes place with EtOH to form the C 7 alcohol, even at lower initial EtOH/IAOH molar ratios (Exp. B4). The composition of IAOH liquid byproducts, shown in Figure S1c, indicates that formation of the initial aldehyde intermediate (3-methyl-butanal) of IAOH is significant, but the subsequent condensation of the intermediate to the C 10 product alcohol is slow. Steric hindrance resulting from the longer carbon chain length likely plays a role in condensation to form the C 10 product. The conversion rate of IAOH to liquid and gas byproducts, based on outlet concentrations of species in Figure S1, is similar to that of EtOH. | 9 |
228832866 | Kinetic Model Development A kinetic model has been developed, based on prior studies of condensed-phase ethanol conversion [22,[31][32][33], to characterize reaction rates in the EtOH/IAOH reaction system. The following Guerbet (condensation) reactions are considered: In addition to these Guerbet reactions, two additional reactions (assumed to be first-order in alcohols) are required to account for conversion of EtOH and IAOH to gas and liquid byproducts. Including these reactions is necessary to maintain the correct feed alcohol concentration profile in the reactor. EtOH side reactions : C 2 H 5 OH Since the selectivities to C 8 and C 9 alcohols formed in continuous reactor experiments were low, the formation of C 8 product alcohols is combined with C 6 alcohol formation, and the formation of C 9 product alcohols is combined with C 7 alcohol formation in the kinetic model. This is warranted because C 8 and C 9 alcohols are formed via further reaction of C 6 and C 7 alcohols with EtOH, respectively, as opposed to reactions of higher alcohols (C 4 + C 4 to C 8 , for example). EtOH is both more reactive than higher alcohols and EtOH is present in much higher concentration than other alcohols. The low selectivities to C 8 and C 9 products, and associated uncertainty with their low concentrations in the product mix, does not warrant the additional complexity of another rate expression and rate constant for each in the kinetic model. Initially, kinetic rate expressions for R1-R4 were assumed to be second-order in alcohols. However, this simple second-order model did not provide a satisfactory fit of either batch or continuous reaction data. Analysis of the "indirect" mechanism [27,31,[35][36][37][38] of EtOH condensation to BuOH (see Supplementary Information) [31], where EtOH dehydrogenates to acetaldehyde (AA), AA undergoes aldol condensation to crotonaldehyde (CA), and CA hydrogenates to BuOH, shows that ethanol condensation rate is first-order in EtOH if (1) local H 2 concentration is assumed to be equal to AA concentration, and (2) either EtOH dehydrogenation or AA condensation are rate-limiting. Prior work [33] showed that the presence of water (W), present initially or produced in reaction, inhibits the rate of EtOH condensation to BuOH. Other studies also have shown that the presence of water can limit the extent of dissociative H 2 adsorption on Ni [39,40] and other metal [41,42] surfaces, thus affecting initial alcohol dehydrogenation in the Guerbet reaction system. Therefore, a Langmuir-Hinshelwood (L-H) rate expression can be written for EtOH condensation to BuOH (R1): A similar rate expression can be written for IAOH condensation to C 10 alcohols, if only IAOH is present. For reactions involving EtOH/IAOH mixtures, generating rate expressions based on rigorous analysis of the indirect mechanism is challenging (see Supplementary Information), because H 2 is produced both by EtOH and IAOH dehydrogenation. The rates are thus coupled, and the resulting rate expressions are complex. However, because in this study EtOH is present in larger molar quantities than IAOH, and EtOH reaction rate is faster than that of IAOH, the assumption can be made that H 2 forms predominantly from EtOH. With this assumption, the condensation reaction of IAOH (R3), and the cross-condensation reactions of EtOH with IAOH (R2) and with BuOH (R4) simplify to be first-order only in IAOH and BuOH, respectively. Including the L-H water adsorption term gives the final form of the rate expression for R2-R6. Details of the model development and the explicit rate expressions for R1-R6 are given in Supplementary Information. The rate expressions described above have been applied to experimental data to determine the rate constants; the process to fit the kinetic model to data is given in the sections below. To ensure that these rate expressions best fit the experimental data, several alternate kinetic models were evaluated. In addition to the simple second-order rate expression, L-H rate expressions with water adsorption and the numerator second-order in alcohols were examined. Similar L-H rate expressions with EtOH, IAOH, or BuOH as the dominant adsorbing species were also examined. None of these kinetic models provided as good a fit to experimental data as the model that is first-order in alcohols with water as the dominant adsorbing species. | 10 |
228832866 | Continuous Reactor Modeling The experimental data from the continuous reactor were used to determine the values of the rate constants for R1-R6. This was accomplished by writing the differential molar balances for each species in the reaction system (Equations (1)-(8) below) and numerically integrating them (using Euler's method in Microsoft Excel) to determine outlet concentrations from the reactor at each residence time. Reactor feed concentrations were calculated from densities of EtOH and IAOH at each reaction temperature and are given in Table S2 of the Supporting Information; the inlet concentrations vary significantly over the temperature range from 210 • C to 250 • C because the feed is an expanded liquid at these conditions close to the critical temperatures of each alcohol. For brevity in the following equations, EtOH (C 2 H 5 OH) and IAOH (C 5 H 11 OH) are represented as E and IA, BuOH (n-C 4 H 9 OH) and C 10 H 21 OH are represented as the C 4 and C 10 condensation products of EtOH and IAOH, respectively. The terms C 6 , C 7 , C 8 , and C 9 refer to multiple cross-condensation alcohol products with the designated carbon number (Figure 1); identification of the structure of each individual alcohol with these carbon numbers was not attempted. Reaction rates r i in Equations (1)-(8) refer to Reactions 1-6 above. | 11 |
228832866 | Rate Constant Determination from Continuous Reactor Data Evaluation of the observable modulus ηϕ 2 at the reactor inlet at 250 • C (Supporting Information) shows that there are, in the worst case, modest intraparticle mass transfer resistances in the reactions studied. Values of the six rate constants and the adsorption equilibrium constant for water (K W ) were adjusted independently at each reaction temperature to minimize the objective function, taken as the sum of the square of differences between experimental and modeled outlet concentrations ((C i Exp − C i Mod ) 2 ) at each residence time for pertinent species in each reaction. Rate constants for the reactions of EtOH (k 5 ) and IAOH (k 6 ) to byproducts were determined by setting the quantity of byproducts formed equal to the quantity of each feed alcohol reacted that was not converted to higher alcohol product, thus maintaining the correct feed alcohol concentration profile through the reactor. Depending on the conditions, the fraction of EtOH or IAOH converted to byproducts ranged from 12% to 33% in the continuous reactor. From the optimized rate constant values at each reaction temperature (210 • C, 230 • C, and 250 • C), an Arrhenius plot for each rate constant was generated to determine the activation energy and pre-exponential factor. The Arrhenius plots are shown in Figure S2 of the Supporting Information. Values of activation energies and pre-exponential factors for each reaction, along with the value of the rate constant at 230 • C, are given in Table 3 below. Table S3 of Supporting Information. A comparison of the rate constants at 230 • C in Table 3 for the various condensation reactions shows a decrease in value as alcohol chain lengths increase from C 2 -C 2 (k 1 ) to C 2 -C 5 (k 2 ) to C 5 -C 5 (k 3 ). The activation energy for these three condensation reactions also increases as the chain length increases, in accordance with the expected steric effects associated with the longer carbon backbone of the alcohols. Interestingly, the rate constant (k 4 ) for (C 6 + C 8 ) formation from C 2 plus C 4 is larger than that of C 2 -C 2 condensation, and the activation energy for R4 is lower. It is possible that the kinetic model does not capture the formation pathway of (C 6 + C 8 ) alcohols correctly (e.g., perhaps there is a direct route to C 6 formation that does not involve C 4 explicitly), or that C 4 and C 6 alcohols, once formed, have a locally higher concentration within the catalyst that results in locally higher reaction rates and thus a larger rate constant. A comparison of the rate constants at 230 °C in Table 3 for the various condensation reactions shows a decrease in value as alcohol chain lengths increase from C2-C2 (k1) to C2-C5 (k2) to C5-C5 (k3). The activation energy for these three condensation reactions also increases as the chain length increases, in accordance with the expected steric effects associated with the longer carbon backbone of the alcohols. Interestingly, the rate constant (k4) for (C6 + C8) formation from C2 plus C4 is larger than that of C2-C2 condensation, and the activation energy for R4 is lower. It is possible that the kinetic model does not capture the formation pathway of (C6 + C8) alcohols correctly (e.g., perhaps there is a direct route to C6 formation that does not involve C4 explicitly), or that C4 and C6 alcohols, once formed, have a locally higher concentration within the catalyst that results in locally higher reaction rates and thus a larger rate constant. | 12 |
228832866 | Comparison of Batch Experimental Data with Kinetic Model Simulation The kinetic model developed above was applied to batch reactions conducted by writing the molar balance for each species "i" in the batch reaction system: The reaction rates for each species are identical to the right-hand side of Equations (1)-(8) above for the continuous reactor system. The molar balances were integrated over the batch reaction time for each experiment using the Euler's method in Microsoft Excel. The rate constants determined from the continuous reactor data at 230 °C (Table 3) were used in the rate expressions. Initial concentrations of EtOH and IAOH for each experiment are given in Table S4 of Supporting Information. A comparison of experimental and simulated concentrations at the end of each batch experiment for key species in the reaction system is given in Figure 3a-d below. Given that the kinetic model is derived entirely from continuous reactor data, the agreement between experimental and simulated batch results is good. The complete comparison of batch experimental and simulated species concentrations is given in Table S5 of the Supporting Information. | 13 |
228832866 | Comparison of Batch Experimental Data with Kinetic Model Simulation The kinetic model developed above was applied to batch reactions conducted by writing the molar balance for each species "i" in the batch reaction system: The reaction rates for each species are identical to the right-hand side of Equations (1)-(8) above for the continuous reactor system. The molar balances were integrated over the batch reaction time for each experiment using the Euler's method in Microsoft Excel. The rate constants determined from the continuous reactor data at 230 • C (Table 3) were used in the rate expressions. Initial concentrations of EtOH and IAOH for each experiment are given in Table S4 of Supporting Information. A comparison of experimental and simulated concentrations at the end of each batch experiment for key species in the reaction system is given in Figure 3a-d below. Given that the kinetic model is derived entirely from continuous reactor data, the agreement between experimental and simulated batch results is good. The complete comparison of batch experimental and simulated species concentrations is given in Table S5 of the Supporting Information. Reactions 2020, 3, x FOR PEER REVIEW 10 of 13 | 14 |
20034388 | ________________________________________________________________________________ Abstract The objective of this study was to evaluate the effect of a polyclonal antibody preparation (PAP) against specific ruminal bacteria on the in situ degradability of dry-grounded maize grain (DMG), high moisture maize silage (HMMS) starch and citrus pulp (CiPu) pectin. Nine ruminally cannulated cows were used in a 3 x 3 Latin square design, replicated three times in a factorial arrangement of treatments of two rumen modifiers represented by monensin and PAP plus a control group, and the three energy sources (DMG, HMMS and CiPu). Each period had 21 days, where 16 were used for adaptation to treatment and five for data collection. The group treated with PAP showed an effect on the soluble fraction (“a”) of DMG starch, decreasing it by respectively 45.3% and 45.4% compared to the CON and MON groups. No effect of PAP was observed for any in situ degradability parameters of starch from HMMS or pectin of CiPu. It was concluded that the polyclonal antibody preparation had limited effect on the in situ degradability of the tested energy sources. ________________________________________________________________________________ | 1 |
20034388 | Introduction The use of ionophores for ruminal fermentation modulation has been employed with great success for better utilization of diets.However, the possible health effects of the use of these additives are a cause for concern and new methods of ruminal fermentation manipulation are beginning to be tested.The European Community, a major importer of meat from Brazil, by Regulation (EC) 1831/2003(Europe, 2003)), banned the use of antibiotics and coccidiostats as feed additives for cattle.This regulation reinforces the need of new feed additive development.The objective of this study was to evaluate the in situ degradation of the dry matter and starch from dry-grounded maize grain (DMG), high moisture maize silage (HMMS) and pectin from citrus pulp (CiPu), as influenced by a polyclonal antibody preparation against specific rumen bacteria in cows fed a high concentrate diet.The bacteria species are Streptococcus bovis, Fusobacterium necrophorum, Clostridium aminophilum, Peptostreptococcus anacrobius and Clostridium sticklandii. | 2 |
20034388 | Materials and Methods The trial was conducted at the College of Veterinary Medicine and Animal Science at the University of São Paulo (USP), Brazil.Nine ruminally cannulated Holstein x Zebu non-pregnant dry cows (690 44 kg BW) were used in 3 x 3 Latin square experimental design with three periods of 21 d each.Treatments were arranged as a 3 x 3 factorial arrangement of two all-feed additives monensin ([MON] or polyclonal antibody preparation [PAP]), plus a control group and three energy sources in the diet (dry-grounded maize grain [DMG], high moisture maize silage [HMMS] and citrus pulp [CiPu]).Cows were housed in a tie-stall barn equipped with individual feed bunks, rubber-matted floors and automatic water fountains common to two animals.There were fans in the ceiling in order to relieve the high temperatures during the day.Body weight was measured at the beginning of period one (d 1) and at the end of each of the three periods (d 21) at the same time each day. Diets were fed as total mixed rations (TMR) with a ratio of concentrate to forage of 70 : 30 (DM basis, Table 1).Diets were offered twice daily at 08:00 and 16:00 for ad libitum consumption (minimum of 10% feed refusal).The forage source was fresh sugarcane chopped to a theoretical average particle size of 1.18 cm; measurement taken by the Penn State Particle Size Separator (Lammers et al., 1996).MON and PAP were offered directly through the rumen cannula twice daily, just before the meals.MON (Rumensin, Elanco Animal Health, Indianapolis, I.N., USA) at 300 mg/animal/day was administered in absorbent tissue paper and PAP (CAMAS Inc., Le Centre, MN) at 10 mL/animal/day using a 10 mL syringe.The latter product contained antibodies against Streptococcus bovis, Fusobacterium necrophorum and some strains of proteolytic bacteria (Peptostreptococcus sp., Clostridium aminophilum and Clostridium sticklandii). Each period had 21 days, where 16 days were used for adaptation to treatments and five days for data collection.The in situ degradability of DM and starch or pectin from the energy sources was measured by the nylon bag technique (Mehrez & Ørskov, 1977).Dry matter was determined according to AOAC (1990).Starch concentration was determined by the method described by Pereira & Rossi (1995) after extraction of soluble carbohydrates (Hendrix, 1993).Pectin was determined by the method described by Van Soest et al. (1991). For degradation, parameters were estimated using the model proposed by Ørskov & McDonald (1979): p = a + b (1-e -ct ), where p is the degradation at each time; "a" is the soluble fraction; "b", the potentially degradable fraction of the insoluble fraction that is degraded at a rate "c"; "c" is the rate of degradation of fraction "b"; and "t" is the incubation period in hours.The parameters "a", "b" and "c" from exponential equation were used to calculate the potential degradability (Pd = a + b), which represents the quantity of feed that can be solubilized or degraded in the rumen if time is not a limiting factor.The effective ruminal degradability (Ed) was calculated according to the mathematical model proposed by Ørskov where K is the passage rate of solids from the rumen, accepted here as either 0.02, 0.05 or 0.08 %/h.Degradability data were calculated by the difference in weight of nylon bags before and after rumen incubation and adjusted according to the equation of Ørskov & McDonald (1979).Results were analyzed by the Statistical Analysis System software (SAS, 2001).Firstly, the residue normality was verified by the Shapiro-Wilk test (PROC UNIVARIATE).Data (dependent variable) that did not meet this assumption were submitted to logarithmic transformation [Log (X+1)] or square root adjustment [RQ (X+1/2)].Original or transformed data, when this last procedure was necessary, were submitted to analysis of variance by PROC GLM (General Linear Models) procedure.The model accounted for the effect of feed additive, energy source, the interaction of feed additive x energy source, period and animal.The effects of the main factors (feed additive and energy source) were separated by Duncan test.Effects were declared significant at P 0.05. | 3 |
20034388 | Results and Discussion The results of the influence of polyclonal antibody on the in situ degradability parameters of starch from DMG and HMMS and pectin from CiPu are presented on Tables 2, 3 and 4, respectively. The group treated with PAP showed an effect (P = 0.037) in the soluble fraction "a" of DMG starch, decreasing it by 45.3% and 45.4% compared to the CON and MON groups, respectively (Table 2). It was observed that the treatment with MON decreased the value of the potentially degradable fraction "b" of DM of HMMS by 16.1% compared to the CON group, but there was no difference when PAP was administered (Table 3).No effect of rumen modifier was observed for any of the in situ degradability parameters of starch of HMMS.In general, irrespective of treatments, in situ degradability values of HMMS were higher than the ones described by Jobim et al. (1999).These authors mentioned that high moisture maize silages had higher soluble fractions "a" in comparison to whole plant or ear of maize silages (grain + | 4 |
96077953 | Photothermal reactions of the dimers of nitrosobenzene, m-chloronitrosobenzene, and pchloronitrosobenzene were studied in solid-state by IR spectroscopy at low temperatures and by X-ray powder diffraction. It was found for the first time that photothermal cycle (photolytic dissociation followed by thermal dimerization) could successively be performed also with Z-configured dimeric nitrosobenzene. Halonitrosobenzenes dimers with E-configuration afforded different photo behavior depending on the position of halogen atom on the benzene ring: while m-halonitrosobenzenes do not dissociate under UV irradiation, p-chloronitrosobenzene, as well as previously studied p-bromonitrosobenzene photolyses very efficiently with recovering of the original crystal phase. Kinetics of thermal dimerization was measured in solid-state, and it was found that the reaction phase transformation occurs as a two-dimensional growth through the crystal. (doi: 10.5562/cca1714) | 1 |
96077953 | INTRODUCTION While nitrosobenzenes appear in solution as equilibrium of two forms, monomers and dimers, in solid-state most of them crystallize predominantly in the form of dimers (azodioxides). 1 In our previous work we have found that under cryogenic conditions in solid state, such azodioxides undergo photodissociation to corresponding nitrosobenzene monomers, which, in turn, redimerize quickly by warming above some critical temperature. 2Since these processes include breaking and rebinding the azodioxide nitrogen-nitrogen bonds, the system represents a sort of molecular OFF-ON switch, (Scheme 1). The reaction mechanism of such a solid-state photodissociation of p-bromonitrosobenzene dimer was studied in detail by in situ X-ray diffraction analysis of the single-crystal-to-single-crystal transformation. 3Fast thermal redimerization above 170 K was explained as a consequence of a very close contact of neighboring Natoms in crystals of in situ prepared monomers.This non-covalent distance is even for 23 % shorter than the sum of the van der Waals radii. For possible application of such a molecular OFF-ON switch, the system must satisfy the condition that the dissociation-dimerization process is operative not only under cryogenic conditions, but also at room tem-perature.In this line it becomes necessary to search for more promising systems, which could afford such photothermal effect. In this work we extend the investigation of reactivity, kinetics, as well as topochemistry of nitrosobenzene derivatives to Z-nitrosobenzene dimer 1, and mand p-chloronitrosobenzene, 2 and 3 (Scheme 1).Structure 1 is interesting because of its Z-stereochemistry.Namely, all the nitrosobenzene dimers previously studied by solid-state photochemistry were E-stereomers.Investigation of 2 and 3 is expected to provide new information about the effect of molecular packing on the photodissociation in the crystal lattice.Position of the chlorine atom on the benzene ring could have critical influence on the reaction path. | 2 |
96077953 | EXPERIMENTAL Nitrosobenzene dimers were prepared by standard methods. 4hotolysis.A high-pressure Hg lamp 250 W was used for photolysis.FT-IR kinetics.The solid-state dimerization rate was measured by following the temporal change in transmittance of the ONNO asymmetric stretching signal at 1258 cm −1 and the NO stretching signal of monomer at 1494 cm −1 .Bruker Equinox FT-IR spectrometer with 1 cm −1 resolution was used for this measurement.The sample was prepared as a standard KBr pellet cooled by Leybold-Heraeus ROK 10 -300 cyclic helium cryostat.Powder diffractogram was taken on Philips PW 1840 diffractometer, Bragg-Brentan geometry, 2θ = 5-35°. | 3 |
96077953 | RESULTS AND DISCUSSION Nitrosobenzene dimer, 1.After photolysis of crystals of dimer 1 in KBr pellet at 23 K by a high-pressure Hg lamp, the signals at 1398 cm −1 and 1412 cm −1 assigned to symmetric and asymmetric stretching vibrations of the Z-ONNO group strongly decreased in their intensity, and the new signals at 1503 cm −1 , originated from N=O stretching vibration of the nitroso monomer, appeared in the spectrum (Figure 1b). By warming the sample to room temperature, the signals of the starting dimer were recovered, while the signal of the monomer disappeared (Figure 1c).Because the process can be visualized as changing the color from yellowish (dimer) to blue (monomer), the reaction is also an example of photochromic/thermochromic effect.The observed temperature of this thermal transition from monomer to dimer was between 265 K and 275 K.The photolysis of 1 has been repeated at different temperatures, and it was found that the highest temperature at which this compound undergoes photochromic dissociation is 245 K.This temperature is much higher than in the case of previously observed photoreaction of p-bromonitrosobenzene (170 K). 2 The transformation cycle that includes photodissociation followed by thermal redimerization was repeated five times.Relative intensity of the 1503 cm −1 band assigned to the monomer NO stretching vibration was more or less recovered after an each cycle (Figure 2).Evidently, this OFF-ON switching system has a high efficiency. Chloronitrosobenzene dimers, 2 and 3. Irradiation of m-chloronitrosobenzene dimer 2 cooled in KBr pellet to 20 K did not afford any change in the IR spectrum.No dissociation was observed at any temperature between 15 K and the room temperature.The same experiment was made with m-bromo derivative of dimer 2 which also did not afford photodissociation.In contrast, dimer 3, in which the halogen atom is in para position, readily undergoes photodissociation at 25 K.The effect was characterized by a disappearance of the IR signal at 1258 cm −1 assigned to asymmetric stretching vibration of the E-ONNO group, 5 and the appearance of the signal characteristic for monomer NO stretching vibration at 1494 cm −1 (Figure 3).The thermal redimerization started at the temperature as high as 295 K.Moreover, at this temperature we have succeeded to measure kinetics of dimerization by following the intensity of the disappearing NO stretching band at 1494 cm −1 .The obtained kinetic curve is a sigmoid that is typical for solid-state reactions and phase transformations (Figure 4). 6From the analysis of the reaction by using the standard Avrami-Erofeev model, the reaction in the crystal can be described as a two-dimensional growth of the product phase. 6Namely, linear plot of logarithms of the extent of the reaction, (α) versus logarithm of time (Sharp-Hancock plot) gives the coefficient m = 2.58 characteristic for the two-dimensional process (Figure 5).Phase reversibility of the photothermal cycle.The powder X-ray diffractograms were recorded for polycrystalline samples before photolysis, and at the end of the cycle, i.e. after thermal redimerization.As it can be seen in Figure 6, the diffractograms do not differ, and it follows that the compound after photodissociation followed by redimerization recovers its origins crystal phase. This finding supports the previous conclusions about the topochemical reversibility of such cycle, obtained from observations of the single-crystal-to-singlecrystal transformations.The hindered solid-state photodissociation of meta halogen derivatives (2 and 4) can be explained by formation of interhalogen bonds 7 (Cl---Cl, or Br---Br) in their crystal lattice (Figure 7).The Br…Br contacts are identified by typical interatomic distance of 3.76 Å.If such bonds are in meta-position, they can hinder the necessary partial rotation of benzene rings, which always accompanies dissociation.Oppositely, benzene rings have freedom to rotate partially and to enable dissociation if interhalogen bonds are formed between halogens in para-position (Figure 7).Note, that 2 and 4 are isostructural because they have analogous unit cell, which for 2 have parameters a (Å) 12.302(2), b (Å) 3.268(1), c (Å) 13.261(4), beta (°) 107.53( 6)). | 4 |
73665529 | Water and nitrogen are essential for the optimal development of corn plants. A deficiency of these elements leads to lower crop production. Also, the health status of a plant influences the photosynthesis process. The photosynthetic diagnosis of a plant from the chlorophyll fluorescence spectrum induced by laser is non-destructive to the sample, reliable and fast method. As part of this work, we showed that it is possible to detect the nitrogen and water deficiencies of corn from the chlorophyll fluorescence ratio at 690 nm and 740 nm, when the measurements are performed before the senescence phase. Indeed, we found that the R fluorescence ratio increases over time, for any stress on the plant. However, R decreases with the nitrogen stress and increases with increasing water loss. The measures should be performed 51 Days After Planting (DAP) to detect water deficiency and the suitable date for nitrogen deficiency detection is 61 DAP. Before each of these dates, the plants will be considered water deficient if the fluorescence ratio R ≤ 1.34 and will be nitrogen stressed if R > 1.36. | 1 |
73665529 | Introduction Corn is the most consumed cereal in the world.Indeed, it represents 41 % of world cereal production (Perrier-Brusle, 2010).It is mainly used for feeding cattle in industrialized countries, but in sub-Saharan Africa and Latin America, it is used to feed the population (Bassalet, 2000).In Côte d'Ivoire, the 2014 national production of this cereal exceeded 600 000 tonnes (Réseau Non-Gouvernemental Européen sur l'Agroalimentaire le Commerce l'Environnement et le Développement [RONGEAD], 2014).However, the country is not self-sufficient in this cereal.It is forced to import corn to provide industrial and agro-pastoral needs.Therefore, it is necessary, even imperative to increase the production of this cereal to meet the existing needs and ultimately ensure food security of the Ivorian population.In Côte d'Ivoire, the corn growing areas are mainly located in Savannah, low rainfall area (Yéo, 2011). Water and nitrogen are essential mineral elements for the optimal development of corn plants (Saccardy, 1997;Plénet, 1995;PNTTA, 1999).A deficiency in these elements leads to lower crop production.In agronomy, detecting the nutritional deficiencies of plants is usually carried out by foliar diagnosis which is a destructive method. The fluorescence emission is directly related to the photosynthesis process (Papageorgiou & Govindjee, 2004;Stirbet & Govindjee, 2011;Wim & Andrej, 2013) in which are made of many biological exchanges.The health status of a plant influences this process.Thus, the study of the fluorescence spectrum can detect any stress on the plant at leaf and canopy scale (Chappelle, Wood, McMurtrey & Newcomb, 1984;Méthy, Olioso & Trabaud, 1994;Bourrié, 2007).The interest of this photosynthetic diagnosis is that it is non-destructive, fast and reliable.As part of this work we characterize the water and nitrogen deficiencies of corn plants by chlorophyll method of laser-induced fluorescence. | 2 |
73665529 | Experimental Material Data were collected in vivo and in situ using an USB4000 -type FL fluorescence spectrometer.This device can record plant chlorophyll fluorescence spectra whose wavelengths range is from 360 nm to 1 000 nm in steps of 0.22 nm.The samples were excited by a LED emitting at 450 nm through a bifurcated optical fiber.The acquisition, storage and processing of the collected spectral data were conducted using a laptop.The Figure 1 shows the experimental setup. | 3 |
73665529 | Water Stress Induction In the case of the water stress study, the corn planting was made in a greenhouse as we did not want to be dependent on the weather and we had to control the water amount we had to provide to the corn plants. A mineralogical analysis of the soil used to fill the buckets revealed that it had high content of.all essential nutrients for the corn plants development. We first sought the soil field capacity : it is the amount of water that the ground can retain.Knowing this value allowed us to determine the various doses to apply to the soil to induce the hydric stress.The field capacity of the used ground was 2 liters.We then generated four levels of water stress as listed below: W12: 12.5 % of the soil field capacity per bucket (0.25 l of water) W25: 25 % of the soil field capacity per bucket (0.5 l of water) W50: 50 % of the soil field capacity per bucket (1 l of water) W100: 100 % of the soil field capacity per bucket (2 l of water) After a heavy watering the day before, we sowed corn grains the next day.The plantation in the greenhouse consisted of 72 buckets of 20 l capacity, left in 3 blocks (see figure 2). Figure 2. Water stress study planting plan Every bucket contained two growth pouches at the rate of three grains per pouch.We removed corn plants from the bucket, to have a unique plant in a growth pouch 15 Days After Plantation (DAP).So, every bucket contained two corn plants. We induced the water stress 30 DAP.Then, we started to collect spectral data 37 DAP.From this date and once a week, the fluorescence spectrum of every plant was recorded.This operation took place between 09:00 am and 1:00 pm.This phase ended 72 DAP when plants reached the senescence phase. | 6 |
73665529 | Nitrogen Stress Induction The buckets were filled with poor nitrogenous soil, in order to control the intake of nitrogen fertilizer.Each bucket with a capacity of 30 liters had three growth pouches with three seeds per growth pouch. We brought an amount of 2.27 g of nitrogen, phosphorus and potassium (NPK ) to every hole to allow a good seeding of the corn grain.Then, the corn seedlings were thinned to one plant per hole 15 DAP.So, there were only three plants per pot. The nitrogenous stress was led 30 DAP by providing various doses of urea.So, we generated five fertilization levels as listed below: N0: 0 g of urea/plant (no nitrogen provided to the plant) N1: 0.377 g of urea/plant (1/4 part of the nitrogen recommended dose) N2: 0.755 g of urea/plant (2/4 part of the nitrogen recommended dose) N3: 1.133 g of urea/plant (3/4 part of the nitrogen recommended dose) N4: 1.510 g of urea/plant (nitrogen recommended dose). This plantation consisted of 80 buckets of 30 l capacity, left in 4 blocks.Every block contained the 5 fertilization levels and each fertilization level included 4 buckets (see figure 3).Ten days after the application of nitrogen stress; that is 40 DAP, we began collecting spectral data.From that date, once every week, the fluorescence spectrum of each plant was recorded.This operation that ended 82 DAP took place between 09:00 am and 01:00 pm.A total of seven series of measurements were carried out during the different development stages of corn plants. | 7 |
73665529 | Data Processing During the measures at leaf scale, every deficiency level (hydric or nitrogenous) applied to the plant in the same block, is characterized by the average fluorescence spectrum. We noticed that for the same applied stress level, there is no significant difference between the measurements performed on the blocks.We then worked with the average values of the ratios R computed on the blocks, for the same given deficiency level. For all the recorded spectra, the digital data are converted to text files and then imported into the MATLAB software to compute the ratios of intensities of the two characteristic chlorophyll fluorescence peaks (R = F 690 /F 740 ).F 690 corresponds to the intensity of the fluorescence peak at 690 nm and F 740 is the intensity of the fluorescence peak at 740 nm.We used the fluorescence ratio in our study, among other fluorescence parameters as it is a pertinent indicator, widely used in plant stress detection (Tremblay, Wang & Cerovic, 2012). The various graphics were edited with the software ORIGINPro 8. R values given on the charts are the average values for every deficiency level.Indeed, it is recommended to use the mean value of ratio for many measurements for several plants to have reliable results instead of one single measurement (Fedotov, Bullo, Belov & Gorodnichev, 2016). | 8 |
73665529 | Water Stress Case The graphs in Figure 4 show for each stress level, the intensities of fluorescence ratios depending on the development stage of corn plants.For all treatments, we notice an increase in the value of R depending on the plant development stage.Thus, the value of R increases with the plant age.From 51DAP to 65DAP each curve compared to other is a function of the nutritional stress: greater the stress is, smaller R is. From the date 51DAP, we also find that the curves (W12, W25) and (W50, W100) are close to each other.The differences between the ratios values for considered couples treatments are weaker at 65DAP.We can then consider the two extreme curves : W12 represents stressed plants and W100 represents non-stressed ones.At 51DAP the gap between the extreme curves is maximum.It would be the indicated date for the water stress detection.The water deficiency detection measures are efficient in the time interval [51DAP, 65DAP]. As the histograms in Figure 5 show, until 51DAP, all water -deficient plants have a ratio R ≤ 1.34.But, for nondeficient plants the ratio is still greater than 1.34.In addition, as water is an essential element for plant survival, a lack of water causes early senescence.This is the case from 58DAP.Then, we notice that all plants have R > 1.34.So, the appropriate time to make the measures for the hydric stress detection would be 51DAP. | 9 |
73665529 | Nitrogen Stress Case The charts in figure 6 show the fluorescence ratio over the treatment applied to corn plants.We find that at any plant development stage, the ratio R decreases when stress decreases. According to Méthy, Olioso & Trabaud (1994), the amount of chlorophyll in the plant is proportional to the photosynthetic activity.However, the nitrogen deficiency causes the decrease of the activity.The ratio R therefore increases when the nitrogen stress decreases.Figure 6.Changes in the relationship between the fluorescence ratio and the nitrogen treatment The Figure 7 displays the fluorescence ratios over the plant development stage, for each nitrogenous stress level.Despite serrated evolution of certain values, we observe for all treatments, an increase of the R value depending on the plant development stage.Thus, the R value increases with the plant age.This increase is more pronounced for N0 and N1 treatments than for those of N3 and N4. We also notice on Figure 7 that charts (N0, N1) and (N3, N4) are close to each other. The median position of the N2 treatment chart compared to curves treatments couples (N0, N1) and (N3, N4) illustrates the average fertilization rate that we applied.Furthermore, the arrangement of each chart compared to other highlights a parallelism with different fertilization levels we generated. The table 1 shows the differences between the pairs of curves (N0, N1); (N3, N4) and (N0, N4).Table 1 shows that the greatest differences between the fertilization levels during the plant development, are obtained at 61 DAP and 82 DAP.We cannot consider the second date because it is already in the plant senescence phase.Thus, the best period to conduct early nitrogen stress detection measurements would be 61 DAP. This table also shows that the differences between N0 and N1 on one hand and N3 and N4 on the other hand are very low compared to the differences between N0 and N4.N1 and N0 Fertilizations produce the same effect of stress on the plant.It would therefore be useless to bring 25 % of the nitrogen needs to the plant.However, it would be economical for the farmer to provide 75 % of the nitrogen needs of the plant because the N4 and N3 treatments produce the same stress effect. We then considered both extreme fertilization levels : -nitrogen deficient level for N0 treatment plants; -nitrogen fertilized level for plants that have undergone the N4 treatment. For both generated fertilization levels, figure 8 shows the fluorescence ratio over the development stage. The maize variety used in this study has a short-cycle production (90-95 days).At 70 DAP, the culture is in the senescence process.Figure 8 shows that the fertilized plants have a ratio R = 1.36 on that date.All measurements performed before the senescence phase are such that: -R ≤ 1.36 for fertilized corn plants; -R > 1.36 for deficient corn plants. Moreover, the measures we took during the senescence phase provide R values greater than 1.36 whatever studied plants.In addition, the R value for fertilized plants is still lower than deficient plants. | 10 |
225684425 | Objective: To assess the efficacy of agitation of chlorohexidine (CHX) and Silver nanoparticles “AgNps” with 810nm diode laser or sonic endoactivator compared to side –vented needle on infected root canals with Enterococcus “E” Faecalis biofilms. Material and Methods: Sixty-five extracted human premolars with single oval canals were instrumented by protaper system up to F3. Biofilms of E. faecalis were generated based on a previously established protocol. Two teeth were used to check the biofilm formation, then the remaining Teeth were randomly divided into three equal experimental groups according to agitation techniques used: group 1 (810 nm diode laser with 1 watt) , group 2 (sonic endoactivator) and group 3 (Side vented needle). Each group was further divided into three equal subgroups according to the irrigant solution into; subgroup A: chlorohexidine, subgroup B: silver nanoparticles and subgroup C: distilled water: Confocal laser scanning microscopy “CLSM” was used to assess bacterial viability. Data were analyzed by appropriate statistical analyses with P = 0.05. Results: Regarding the activation method, all groups had a significantly high percentage of dead bacteria (P < 0.05). However, Laser was significantly the highest and Endoactivator the least (P < = 0.001). Diode laser agitation of AgNps irrigant showed the highest reduction percentage of bacteria (78.1%) with a significant difference with both CHX and water irrigation, Conclusion: Under the condition of the present study; results reinforced that laser activation is a useful adjunct, 810 nm diode laser agitation of AgNps or chlorhexidine was more effective in disinfection of oval root canals than endoactivator and side vented needle techniques. RESUMO Objetivo: Avaliar a eficácia da agitação de clorohexidina (CHX) e nanopartículas de prata (AgNps) , com laser de diodo de 810 nm ou endoativador sônico, em comparação à agulha de ventilação lateral, em canais radiculares infectados com biofilmes de Enterococcus “E”; Faecalis. Material e Métodos: Sessenta e cinco pré-molares humanos com um único canal oval, extraídos, foram instrumentados pelo sistema protaper até F3. Os biofilmes de E. faecalis foram gerados com base em um protocolo previamente estabelecido. Foram utilizados dois dentes para verificar a formação do biofilme, e os dentes restantes foram divididos aleatoriamente em três grupos experimentais iguais, de acordo com as técnicas de agitação utilizadas: grupo 1 (laser de diodo 810 nm com 1 watt), grupo 2 (endoativador sônico) e grupo 3 (Agulha com ventilação lateral). Cada grupo foi dividido em três subgrupos iguais, de acordo com a solução irrigante; subgrupo A: clorohexidina, subgrupo B: nanopartículas de prata e subgrupo C: água destilada: A microscopia confocal de varredura a laser foi usada para avaliar a viabilidade bacteriana. Os dados foram analisados por análises estatísticas apropriadas com P = 0,05. Resultados: Em relação ao método de ativação, todos osgrupos apresentaram percentual significativamente alto de bactérias mortas (P < 0.05). No entanto, para o laser foi significativamente o mais alto e, para oendoativador, o menos alto (P < = 0.001). A agitação com laser de diodo doirrigante AgNps apresentou a maior porcentagem de redução de bactérias (78,1%), com diferença significativa tanto para irrigação com CHX quanto comágua. Conclusão: Sob as condições do presente estudo; os resultadosreforçaram que a ativação a laser é um complemento útil, a agitação por laserde diodo de 810 nm de AgNps ou clorexidina foi mais eficaz na desinfecção dos canais radiculares ovais do que as técnicas de endoativador e agulha com ventilação lateral. O R I G I N A L A R T I C L E Efficacy of diode laser and sonic agitation of Chlorhexidine and Silver-nanoparticles in infected root canals Eficácia do laser de diodo e agitação sônica de clorexidina e nanopartículas de prata em canais radiculares infectados Latifa Mohamed ABDELGAWAD1, Niven ASMAIL1, Somia Abdel LATIF2, Ali Mohamed SAAFAN1 1 Medical Laser Applications Department National Institute of Laser Enhanced Sciences Cairo University Cairo Egypt. 2 Microbiology and Molecular Biology Department Faculty of Medicine Cairo University – Cairo Egypt. doi: 10.14295/bds.2020.v23i3.1989 UNIVERSIDADE ESTADUAL PAULISTA “JÚLIO DE MESQUITA FILHO” Instituto de Ciência e Tecnologia Campus de São José dos Campos Ciência Odontológica Brasileira | 1 |
225684425 | INTRODUCTION O ne of the main challenges facing the dentists in the endodontic steps is how to totally disinfect the root canal [1]. E faecalis is the most prominent microorganism involved in persistent infections after root canal therapy. E. faecalis has the ability to penetrate the dentinal tubules and cementum. It can survive in biofilm form at anatomical complexities of root canal system, over the foreign bodies like gutta-percha or other obturating materials extending into periapical tissues and can survive for prolonged periods under nutrientdepleted conditions [2]. Trying to overcome the challenge compulsory by the presence of biofilm and reach complete disinfection or significant bacterial reduction in the root canals, many irrigants have been indicated during endodontic treatment. Chlorhexidine gluconate (CHX) at 2% is one of the most commonly used irrigants and considered as an effective antimicrobial agent. It has many properties; broad-spectrum, substantively (extended outstanding activity) and a relative absence of toxicity that recommend it to be used as an endodontic irrigant [3,4]. Silver nanoparticles (AgNps) have gained popularity because of their unique ability to penetrate tissues, interact with bacteria, exhibit potent antimicrobial activity and biocompatibility [5]. The agitation of irrigating solutions with the laser has become common [6]. Researchers examined many laser systems to attain complete disinfection of root canal system and the adjacent dentinal tubules and yet there is still argument about which is the most powerful laser system in regards to providing a sterilized root canal system. The high bactericidal effect of diode laser has been reported in multiple studies [7]. Therefore, due to the bactericidal effect of diode laser and its low cost compared to other commonly used laser systems in endodontic, it can be used in agitation of the irrigation during the mechanical debridement procedures [8]. The Endoactivator System "EA" is a sonically driven irrigant activation system planned to produce dynamic fluid agitation inside the canal that has been shown to improve the effectiveness of irrigation better than the traditional syringe irrigation [9]. So the present study highlighted the effect of 810 nm diode laser and sonic agitation on two types of irrigants; [chlorohexidine (CHX) and silver nanoparticles (AgNps)] applied in root canals. | 2 |
225684425 | Selection and Mechanical preparation of samples Sixty -five extracted human premolars with single oval canal and fully formed apices were selected from hundred extracted teeth for periodontal reasons. Each root was digitally radiographed using RVG 6200 digital sensor (Carestream, Rochester, New York, United States) and measured by its software to select canals with ovality ratio more than 2.5. The crowns were sectioned such that roots were standardized to 12 + 2 mm and stored in labeled vials at 100% humidity. | 4 |
225684425 | Final irrigation and sterilization of the samples Final irrigation was performed with 5 ml 15% Ethylenediaminetetraacetic acid "EDTA" (Endo-Solution, Cerkamed, Stalowa Wola, Polska) for 3 min and 5 ml NaOCl for 3 min to remove the smear layer, and then the canal was irrigated with 10 ml of physiological saline solution to remove the EDTA. Finally, the teeth were sterilized in the autoclave at 121°C for 30 min . | 5 |
225684425 | Inoculation and incubation of the teeth with E faecalis Using a sterile micropipette, twenty microliters of E .faecalis suspension (matching McFarland's turbidity of tube no 0.5) was syringed into each root canal. Each inoculated root was kept in separate sterile test tube with caps in a rack. Then incubated at 37°C for 7 days, to allow the proliferation of microorganisms, and their further penetration into the dentinal tubules and formation of biofilms. | 6 |
225684425 | Classification of the samples: Two teeth were used to check the biofilm formation, then the remaining teeth (63) were randomly divided into three equal experimental groups according to agitation techniques used: group 1 (810 nm diode laser with 1 watt), group 2 (sonic endoactivator) and group 3 (Side vented needle). Each group was further equally divided into three subgroups according to the irrigant solution into; subgroup A: chlorohexidine, subgroup B: silver nanoparticles and subgroup C: distilled water: The agitation mechanisms in the three groups were as a follow: | 7 |
225684425 | Group 1 (diode Laser) Agitation was done with 810 nm Diode laser with continuous mode and output power 1 watt (Zolar lasers, Canada) which delivered into 200 um flexible plain endodontic fiber. The fiber was inserted parallel to root canal wall and used with helicoidally movement in apical-coronal directions. Agitation was done for 10 seconds to 1 ml irrigant. The sequence was repeated 5 times, giving 5 ml total volume and 50 sec total agitations. | 8 |
225684425 | Group 2 (Sonic endoactivator) In this group agitation was done by Sonic endoactivator device (Dentsply, Tulsa) with red polymer tip # 25/0.04 at speed 10000 rpm. The samples in this group were irrigated with 5 ml of an irrigating solution, where each 1ml of the irrigant was followed by 10 seconds of sonic agitation [11]. | 9 |
225684425 | Confocal laser scanning microscopy (CLSM) examination Sixty -five roots were sectioned for detecting viable and nonviable bacteria on root canal walls. Roots were set in blocks of fast setting acrylic resin and two lines were drawn with a marker on the exposed part of the root, one buccal and one palatal for vertically sectioning into two halves, approximately parallel to the tooth axis, utilizing the microtome saw. A sample from each sectioned root was taken for scanning. Each sample was stained by both Acridine Braz Dent Sci 2020 Jul/Sep;23 (3) 4 orange (AO) and Propidium iodide (PI) dyes separately, just before the CLSM examination. Zeiss LSM 710 confocal microscope (Carl Zeiss, Germany) was used with 40 x objectives for scanning. Three random areas of the middle third of the root canal were scanned with a 2-mm step size by the CLSM. For each image the median intensity of green and red bacteria were calculated by the soft-ware (green for live and red for dead bacteria), this number was tabulated and statistically analyzed. | 11 |
225684425 | Data presentation and analysis To identify the effect of activation protocols on bacterial reduction (dead cell %) in each irrigation protocol, one-way ANOVA was applied. Bonferroni's correction for multiple testing was used in one-way analysis of variance. P = 0.05 for the analyses. Twoway ANOVA was performed to weigh the effect of the irrigation protocol and activation method as the two independent variables on the outcome (percentage of dead cells. Data was analyzed using IBM SPSS advanced statistics (Statistical Package for Social Sciences), version 21 (SPSS Inc., Chicago, IL). | 12 |
225684425 | RESULTS The data obtained from the CLSM are tabulated (Table I). Figure 1 shows a homogenous penetration of E. faecalis deep into the dentinal tubules of the root canal. figure 2 shows biofilm destruction within the root canal lumen for all groups. Regarding the activation method, all groups had a significantly high percentage of dead bacteria (P < 0.05). However, Laser was significantly the highest and Endoactivator the least (P <= 0.001). Regarding the irrigant type; AgNps activated with diode laser had the highest percentage of dead bacteria (78.1%) followed by needle agitation (76.47%) then sonic (72.94%). Without significant difference (p > 0.05) In chlorhexidine subgroup, the high percentage of dead bacteria was in laser group (71.81%) followed by needle group (70.18%) then sonic group (68.99) Without significant difference (p > 0.05). while distilled water subgroup showed high percentage of bacterial reduction in laser group (71.46%) followed by sonic (62.7847%) then needle group (60.6%) with significant difference between laser and sonic and laser with needle (p < 0.05) while there was no significant difference between sonic and needle (p >0.05). Table I percent of apparently dead bacterial cells in the biofilm within the dentinal tubules, assessed by confocal laser microscopy after three different activation techniques with three different irrigant. (*) means significant between laser and sonic in H2O irrigant (#) means significant between laser and needle in H2O irrigant (a) Means significant CHX and AgNps within the same group (b) Means significant between CHX and H2O within the same group (c) Means significant between AgNps and H2o within the same group. | 13 |
225684425 | DISCUSSION The main goal of endodontic treatment is the complete disinfection of the root canal system; however, it is difficult due to complex anatomy of the root canal system and biofilm mediated infection. E. faecalis was chosen because it is generally believed that it is one of the most resistant microorganisms found in the infected root canals and endodontic treatment failures [9,10]. The clinical challenge to deliver irrigants into unprepared infected canal extensions; as well as the most apical infected segment recommended the use of automated agitation of irrigant in disinfection of root canal systems [7]. So the present study evaluated the antibacterial effect of activated agitation of diode laser, sonic and side-vented needle with three types of irrigants; Chlorhexidine, AgNps, and distilled water in infected oval root canal with E faecalis. Chlorhexidine (CHX) was selected in the present study as it has a broadspectrum antimicrobial effect and kills E. faecalis in the dentinal tubules. [9]. .as well as AgNps exhibit potential antibacterial activity and does not allow to develop resistance [11] Positively charged AgNps interact with the negatively charged bacterial cell walls, adhere, and penetrate into the bacterial cell leading to the loss of cell wall integrity and permeability [12][13][14][15][16][17]. Diode laser induced cavitation and side vented needle non laminar streaming probably provided better mechanical turbulence to penetrate infected dentin and effectively carry away the microorganisms than acoustic streaming by vibrating inserts of endoactivator [18][19][20]. In the present study the lasing protocol favored the disinfection of the root canal. Through limited studies existed specially on 810 nm diode laser; generally, diode agitation seems promising [6,18]. Agitation of AgNps by 810 nm diode laser I watt for 50 sec improved E. faecalis eradication compared to sonic or needle agitation. Using 10 sec continuous 810 nm diode laser which repeated five times for agitation of AgNps improved e faecalis eradication by 78.05% however inadequacy of diode laser to remove more percentage of bacteria may be due to using of low output power (1 watt) which is in accordance with other studies [21][22][23][24][25][26]. Sonic agitation produced bactericidal effect in the present study probably due to oscillating movement which allow hydrodynamic circulation of the irrigant. A reduced antibacterial efficiency of sonic compared with other techniques may be due to the greater displacement amplitude of the small vigorously vibrating polymer tip, also due To weakened. Currents, impeding microstreaming and irrigant activation in apical part of the root beyond the vibrating tip [27][28][29]. In the present study, laser activated agitation was more efficient than endoactivator Braz Dent Sci 2020 Jul/Sep;23 (3) 6 [18 ].Endoactivator in the present study was less efficient than needle agitation this may be due to vacuum and remove of irrigant before replenishing [30 ].Side -vented needle agitation came after laser and better than sonic as vertical up and down movements of the needle allowed distributing the localized high dynamic flow at the side exit along the oval canal allowed effective reflux of irrigant coronally as previously reported [ 30] . The enhancing effect of 810 nm diode laser agitation in disinfection of oval canals can be complemented by a further study to evaluate other different protocols in canal disinfection with different irrigant and providing better bactericidal effect. | 15 |
216121003 | Studies suggest that cumin oil havemany health and cosmetic bene its such as weight loss, improving skin conditions and also treating cancer and diabetes. People have used these tiny black seeds of N. sativa as a natural remedy for thousands of years. Cumin oil contains thymoquinone, which is an antioxidant and an anti-in lammatory compound having tumor-reducing properties therefore useful in treating cancer. Plant mediated biological synthesis of silver nanoparticles has been gaining importance due to its simplicity and ecofriendliness. The aim of the present study was to prepare cumin oil mediated silver nanoparticles and evaluate it for its anti-diabetic activity .using alpha amylase inhibitory assay. The green synthesised cumin oil mediated silver nanoparticleswerepreparedusing1mMsilver nitrate. The anti-diabetic activity was evaluated by alpha amylase inhibitory assay. The formation of the nanoparticles was con irmed both by visual colour change as well as by scanning the absorbance by UV-Visible spectrophometer between 300 nm to 700 nm. In the present study, cumin oil mediated silver nanoparticles inhibited alpha amylase in a dose dependent manner. Hence, these nanoparticles may be used for control post prandial hyperglycemia. | 1 |
216121003 | INTRODUCTION Nanotechnology is an advanced ield of technology which has lot of application in biomedical ield such as dentistry, neurodegenerative medicine, drug delivery system and so on (Menon et al., 2018;Rajeshkumar and Naik, 2018) The metal nanoparticles such as gold, zinc oxide and silver has wide and unique properties with wide range of applications (Santhoshkumar et al., 2017;Agarwal et al., 2018a;Rajeshkumar, 2016). Silver nanoparticles synthesized using different herbal plants are having wide range of applications in various ields (Rajeshkumar and Bharath, 2017). Silver nanoparticles have many applications in medical ield. The silver nanoparticles synthesized using root extract of Acorus calamus showed very good antioxidant and antibacterial effect against gastrointestinal pathogens (Chellakannu et al., 2019). Silver nanoparticles from lemon grass is reported to have good antidiabetic activity (Agarwal et al., 2018b). The bark extract of Garcinia mangostana mediated nanoparticles showed good larvicidal activity and antimicrobial activity against fungus and disease causing bacteria (Karthiga et al., 2018). The aqueous leaf extract of Clome gynandra mediated silver nanoparticles showed peak at 420 nm and showed good antimicrobial potential (Asha et al., 2017). Many plants are reported to have hypoglycaemic (Roy et al., 2011;Ashwini and Anitha, 2017;Aneesa et al., 2019). Nigella sativa is known for its antidiabetic effect. Extensive studies on N. sativa have been carried out by various researchers and a wide spectrum of its pharmacological actions has been explored. Due to its miraculous power of healing, N. sativa has been top ranked among evidence based herbal medicines. Most of the therapeutic properties of this plant are due to the presence of phytochemicals like thymoquinone which is the major bioactive component of the essential oil (Wafai et al., 2010).It is reported that , the presence of thymoquinone is (30%-48%), thymohydroquinone, dithymoquinone, p-cymene (7%-15%), carvacrol (6%-12%), 4-terpineol (2%-7%), t-anethol (1%-4%), sesquiterpene longifolene (1%-8%) α-pinene and thymol etc (Kanter et al., 2009). Plant mediated biological synthesis of silver nano particles has been gaining importance due to its simplicity and eco-friendliness. Cumin oil was used as the sole reducing and capping agent for the synthesis of silver nanoparticles. In this study, cumin oil mediated silver nanoparticles were evaluated for anti-diabetic activity using alpha amylase inhibitory assay. 1 mM silver nitrate (90 mL) in double distilled water was mixed with 10 mL of cumin oil solution to make 100 mL and kept in an orbital shaker with magnetic stirrer for synthesis of silver nanoparticles .The colour change was observed visually and photographs were recorded. | 2 |
216121003 | RESULTS AND DISCUSSION The Figure 1 depicts the image of the cumin oil mediated silver nanoparticles. There was a visible colour change in the reaction mixture indicating the nanoparticle synthesis induced by cumin oil. Figure 2 shows the UV -Vis spectroscopy of the synthesised nanoparticles. The surface Plasmon resonance peak of cumin oil mediated silver nanoparticles around nm con irmed the formation of silver nanoparticles. Figure 3 showed a dose dependent inhibitory effect of cumin oil mediated silver nanoparticles on alpha amylase enzyme. Inhibitors of this enzyme are potential compounds for management of diabetes. Plants are known for their enzyme inhibitory activity. Many plant mediated oils were used for the green synthesis of different metal nanoparticles for their biomedical application. The present study claims the Alpha amylase inhibitory effect of cumin oil mediated silver nanoparticles. | 5 |
209716123 | Human carboxylesterase 2 (hCE2) is one of the most abundant esterases distributed in human small intestine and colon, which participates in the hydrolysis of a variety of ester-bearing drugs and thereby affects the efficacy of these drugs. Herein, a new compound (23o) with a novel skeleton of dihydrooxazolo[2,3-a]isoquinolinium has been discovered with strong inhibition on hCE2 (IC50 = 1.19 μM, Ki = 0.84 μM) and more than 83.89 fold selectivity over hCE1 (IC50 > 100 μM). Furthermore, 23o can inhibit hCE2 activity in living HepG2 cells with the IC50 value of 2.29 μM, indicating that this compound has remarkable cell-membrane permeability and is capable for inhibiting intracellular hCE2. The SAR (structure–activity relationship) analysis and molecular docking results demonstrate that the novel skeleton of oxazolinium is essential for hCEs inhibitory activity and the benzyloxy moiety mainly contributes to the selectivity of hCE2 over hCE1. | 1 |
209716123 | Introduction Mammalian carboxylesterases (CEs), important members of the serine hydrolase superfamily widely distributed in the lumen of endoplasmic reticulum in various tissues, are responsible for the hydrolysis of a wide range of endogenous and xenobiotic substrates containing ester, amides, thioesters and carbamates. [1][2][3] In human body, hCE1 and hCE2 are the main carboxylesterases, both of which play crucial roles in endo-and xenobiotic metabolism. As one of the most abundant esterases distributed in human small intestine and colon, hCE2 participates in hydrolysis of the ester-bearing drugs (such as irinotecan, prasugrel, capecitabine, utamide) and thereby affects the efficacy of these drugs. [4][5][6][7] For instance, CPT-11 (irinotecan), an anticancer prodrug, exhibits strong anti-colorectal cancer activity by releasing the effective substance SN-38. However, excessive accumulation of SN-38 in the intestinal mucosa leads to delayed-onset diarrhoea even death. [8][9][10] To improve the potential clinical risk of these drugs, some highly specic hCE2 inhibitors have been used in clinical to reduce the local exposure of SN-38 in the intestinal mucosa, thereby ameliorating the intestinal toxicity of 12 Over the past decade, a wide variety of hCE2 inhibitors have been reported, including the natural triterpenoids, 13,14 avonoids, 13-15 1,2-diones 16,17 and etc. Although many compounds with strong hCE2 inhibitory activities have already been developed, the potent and specic inhibitors targeting intracellular hCE2 are still rarely reported. DCZ0358 (Fig. 1) is a novel dihydrooxazolo[2,3-a]isoquinolinium discovered in the synthesis of berberine analogues. [18][19][20] Preliminary screening indicated that DCZ0358 could effectively inhibit the catalytic activity of both hCE1 (IC 50 ¼ 4.04 mM) and hCE2 (IC 50 ¼ 16.03 mM), while its hydrolyzate 23b showed a signicant reduction of the inhibitory activity (hCE1 IC 50 ¼ 36.80 mM; hCE2 IC 50 ¼ 41.75 mM), which demonstrated that the oxazolinium moiety of DCZ0358 is essential for the CE S inhibitory activity (Fig. 1). In the synthesis of derivatives of DCZ0358, we have found that in addition to compound 23d (Fig. 2), other compounds with modication of the substituents on the A and D rings cause structural instability of the quaternary ammonium salt. Moreover, the bioactivity and selectivity of 23d were improved (for hCE2 IC 50 ¼ 6.889 mM with >14.52-fold selectivity over hCE1). These results encouraged us to make further investigation of the structure-inhibition relationships of these berberine analogues as CEs inhibitors. The previously reported synthetic route of DCZ0358 is inconvenient to prepare more derivatives because of the harsh reaction conditions (Scheme 1). 21 Therefore, we designed a new synthetic route using compound 12 as the key intermediate (Scheme 2). Among the obtained new analogues, 23o showed the highest selectivity and the best inhibitory activity (hCE1 IC 50 > 100 mM; hCE2 IC 50 ¼ 1.192 mM, K i ¼ 0.84 mM). It was also found that 23o could inhibit hCE2 activity in living HepG2 cells with the IC 50 value of 2.29 mM, suggesting that the compound has remarkable cell-membrane permeability and is capable for inhibiting intracellular hCE2. Further molecular docking results showed that the methoxyl group at the benzyloxy ring of 23o could tightly bind to the catalytic amino acid Ser-228 via Hbonding, which may account for the high selectivity of 23o on hCE2 over hCE1. | 2 |
209716123 | Synthetic procedures Previously, we reported the synthetic route of DCZ0358 (Scheme 1). 21 However, the application of n-butyl lithium reagent and low temperature condition (À78 C) restricted the synthesis of derivatives. Therefore, developing a feasible route is important for the further medicinal chemistry research. Based on the retrosynthetic analysis (Scheme 1), compound 9 could be synthesized via Suzuki coupling reaction from 10 and 11. Compound 10 could be smoothly prepared from the key intermediate 12. Thus, we developed another route taking commercially available 3,4-dimethoxybenzaldehyde 1 as the starting material (Scheme 4). Compound 1 reacted with DMF and formic acid to afford tertiary amine 2 in 75% yield. 25 Then we added chloroformate to the mixture of 2 and n-butyl lithium under À78 C to produce 16 in 80% yield. 26,27 Next, compound 16 was attracted by electrophilic reagent TMSCN to afford 17 (82% yield). 28 The operation for the hydrolysis of the methyl ester compound 17 to the compound 15 is difficult to be control. Subsequently, both ester and cyano groups were hydrolyzed to carboxyl groups under strong alkaline condition to give 18 (76% yield). Compound 18 was easily dehydrated in the presence of acetyl chloride to obtain compound 19 in 78% yield. 29 However, compound 20 was rather difficult to achieve from compound 18 or compound 19. Aer trying various amines, we found that only ammonium carbonate could react with 19. 30 However, this reaction occurred at a high temperature (280 C) and gave a very low yield (22% yield) of 20. Thus, compound 17 was directly reacted with sodium methoxide to afford compound 21 in 51% yield, followed by demethylation to produce dihydroisoquinoline-1,3-dione 20 with a high yield of 93%. 31 In order to convert 20 to the key intermediate 12, we explored many reagents, such as PCl 5 , POCl 3 , SOCl 2 and PhPOCl 2 , it turned out that PhPOCl 2 behaved the best yield with 47%. 31 The key intermediate 12 reacted smoothly with hydroxyacetal under alkaline conditions to give compound 10 with high yield (98%), 32 and then 10 reacted with various arylboronic acids containing a benzyloxy structure to produce 22 in yields ranging from 46% to 98%. 19 Finally 22 were cyclized under acidic conditions to give a series of dihydrooxazolo[2,3-a]isoquinolinium analogues (Scheme 5, compounds 23d-23o in Fig. 2). The present synthetic route is convenient to scale up and benets further pharmaceutical research. | 3 |
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