1. Department of Geriatrics; The First Affiliated Hospital, Chongqing Medical University; Chongqing China
2. Department of Geriatrics; The third Hospital of Mianyang; Mianyang Sichuan China
3. Department of Geriatrics; Ninth Hospital of Xi'An; Xi'An Shanxi China
4. Laboratory of Stem Cells and Tissue Engineering; Chongqing Medical University; Chongqing China
5. Department of Histology and Embryology; Chongqing Medical University; Chongqing China
6. Institute of Life Science; Chongqing Medical University; Chongqing China
7. Department of Physiology; Chongqing Medical University; Chongqing China