1. Department of Respiratory and Critical Care Medicine, Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing Chao-Yang Hospital-Beijing Institute of Respiratory Medicine, Capital Medical University, Beijing, P.R. China
2. Department of Medical Research, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, P.R. China
3. Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, P.R. China