1 Department of Gastroenterology, Taian City Central Hospital, Taian, Shandong, People's Republic of China.
2 Department of Medicine, Beijing 316 Hospital, Beijing, People's Republic of China.
3 Department of Cerebral Surgery, Taian City Central Hospital, Taian, Shandong, People's Republic of China.
4 Department of Stomatology, Taian City Central Hospital, Taian, Shandong, People's Republic of China.
5 Department of Gastroenterology, Qilu Hospital, Shandong University, 107 Wenhua West Road, Jinan, 250012, People's Republic of China. zuoxiuli_s@163.com.