1. The First Clinical Medical School, Gansu University of Chinese Medicine, Lanzhou, Gansu 730000, China
2. Department of Geriatric Medicine, First People’s Hospital of Tianshui, Tianshui, Gansu 741000, China
3. Department of Cardiology, Pulmonary Vascular Disease Center, Gansu Provincial Hospital, Lanzhou, Gansu 730000, China.