1. Department of Oncology, The First Hospital, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
2. Department of Burns and Plastic Surgery, The 264th Hospital of the PLA, Taiyuan, Shanxi 030001, P.R. China
3. Department of Gastroenterology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
4. Department of Gastroenterology and Hepatology, The First Clinical Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China