1. Department of Geriatric Medicine, Affiliated Hospital of Qinghai University, Xining, Qinghai Province, P.R. China
2. Juxian Hospital of Traditional Chinese Medicine, Juxian, Shandong Provence, P.R. China
3. Department of Radiology, Peking Union Medical Hospital, Beijing, P.R. China
4. Department of Cardiac Surgery, Tianjin Chest Hospital, Tianjin, P. R. China
5. Department of Orthopedics, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei Provence, P.R. China