Affiliation: | 1.Institute of Geriatrics, Beijing Key Laboratory of Aging and Geriatrics, National Clinical Research Center for Geriatric Disease, Second Medical Center of Chinese PLA General Hospital and Chinese PLA Medical School, Beijing 100853, China;2.Department of Gastroenterology, First Medical Center of Chinese PLA General Hospital and Chinese PLA Medical School, Beijing 100853, China;3.Graduate School, Chinese PLA General Hospital and Chinese PLA Medical School, Beijing 100853, China. |