Update app.py

app.py

@@ -472,7 +472,7 @@ class PaperDownloader:
         downloaded_links = []
 
         # Download PDFs
-        for doi in tqdm(dois, desc="Downloading papers")):
+        for doi in tqdm(dois, desc="Downloading papers"):
             try:
                 # Try to download with multiple methods with retries
                 pdf_content = self.download_with_retry(doi)