1. National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases Fourth Military Medical University Xi'an China
2. Department of Gastroenterology Huaihe Hospital of Henan University Kaifeng China
3. Shaanxi Second People's Hospital Xi'an China
4. Department of Gastroenterology Second Affiliated Hospital of Chongqing Medical University Chongqing China
5. Department of Gastroenterology Successful Hospital of Xiamen university Xiamen China
6. Department of Digestive Disease and Yale Center for Pancreatic Disease Yale School of Medicine New Haven Connecticut USA