1. Department of General Surgery, Beijing Hospital, National Center of Gerontology;Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, P.R. China
2. Department of Clinical Nutrition, Beijing Hospital, National Center of Gerontology;Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, P.R. China
3. International Research Center for Medicinal Administration, Peking University, Beijing, China; School of Pharmaceutical Sciences, Peking University, Beijing, China
4. Department of Diagnosis, Medical School of Datong University, Shanxi Province, China
5. Department of Hepatobiliary Surgery, Cancer Hospital of Peking Union Medical College, Chinese Academy of Medical Sciences, National Cancer Center, National Clinical Research Center for Cancer, Beijing 100021, China