1 The First College of Clinical Medical Science, China Three Gorges University, Yichang, China; Institute of Digestive Disease, China Three Gorges University, Yichang, China; Department of Gastroenterology, Yichang Central People's Hospital, Yichang, China.
2 The First College of Clinical Medical Science, China Three Gorges University, Yichang, China; Institute of Digestive Disease, China Three Gorges University, Yichang, China; Department of Gastroenterology, Yichang Central People's Hospital, Yichang, China.. Electronic address: liuwei@ctgu.edu.cn.