Update app.py

app.py

@@ -78,7 +78,7 @@ def search_pubmed(query, retmax=5, mindate=None, maxdate=None, datetype="pdat"):
                                  for author in article['MedlineCitation']['Article'].get('AuthorList', [])]),
         
         article_title = article['MedlineCitation']['Article']['ArticleTitle']
-        abstract_text = article['MedlineCitation']['Article'].get('Abstract', {}).get('AbstractText', [None])
+        abstract_text = article['MedlineCitation']['Article'].get('Abstract', {}).get('AbstractText', [])
         
         if isinstance(abstract_text, list):
             # Join the list elements if abstract is a list