1. Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
2. National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
3. Xiangya Medical School, Central South University, Changsha, Hunan, China
4. School of Life Sciences, Central South University, Changsha, Hunan, China