1. Yantai Nurses School of Shandong , Yantai , Shandong , P. R. China
2. Department of Gastroenterology, Qingdao Hospital, University of Health and Rehabilitation (Qingdao Municipal Hospital) , Qingdao , Shandong 266000 , P. R. China
3. Department of Traditional Chinese Medicine, Qingdao Central Hospital, University of Health and Rehabilitation Sciences (Qingdao Central Hospital) , Qingdao , Shandong , P. R. China