1. Department of Digestive Endoscopy and Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210000, China
2. Department of Gastroenterology, The Second Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu 221006, China
3. Digestive Endoscopy Center, The First Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu 210029, China
4. Department of Gastroenterology, The First People’s Hospital of Yancheng, Yancheng, Jiangsu 224006, China