1. Department of Respiratory Medicine, Jinling Clinical Medical College of Nanjing Medical University, Nanjing, Jiangsu 210002, P.R. China
2. Department of Respiratory Medicine, Yijishan Hospital, Wannan Medical College, Wuhu, Anhui 241001, P.R. China
3. Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu 210002, P.R. China