1. Department of Pulmonary and Critical Care Medicine, The Second Affiliated Hospital of Harbin Medical University, Harbin Medical University, Harbin, China; and
2. National Center for Respiratory Medicine,
3. State Key Laboratory of Respiratory Health and Multimorbidity,
4. National Clinical Research Center for Respiratory Diseases,
5. Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, and
6. Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, Beijing, People's Republic of China