1. Department of Gastroenterology, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China
2. Department of Blood Transfusion, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China
3. Department of Gastroenterology, The Fourth Affiliated Hospital of Inner Mongolia Medical University, Baotou, Qingshan, China