1. Department of Respiratory, The First Affiliated Hospital of Shandong First Medical University, Shandong Provincial Qianfoshan Hospital, Shandong Institute of Respiratory Diseases, Shandong Institute of Anesthesia and Respiratory Critical Medicine, Jinan, China
2. Department of Respiratory, Occupational Diseases Hospital of Shandong First Medical University, Shandong Province Hospital of Occupational Diseases, Jinan, China.