Ying Wang1, Jin Yang1, You-Jin Lu2. 1. Department of Respiratory Medicine, The Second Hospital of Anhui Medical University, No. 678 Fu Rong Road, Hefei, 230601, Anhui, China. 2. Department of Respiratory Medicine, The Second Hospital of Anhui Medical University, No. 678 Fu Rong Road, Hefei, 230601, Anhui, China. luyougolden@163.com.