1. Department of Central Lab, Weihai Municipal Hospital, Cheeloo College of Medicine, Shandong University, Weihai, Shandong 264200, P.R. China
2. Department of Gastroenterology, Weihai Municipal Hospital, Weihai, Shandong 264200, P.R. China
3. Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, SAR 999077, P.R. China
4. Marie College, Shandong University, Weihai, Shandong 264209, P.R. China