1. Department of Respiratory and Critical Care Medicine, Shandong Provincial Chest Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China
2. Department of Respiratory and Critical Care Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
3. Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, P.R. China
4. Department of Respiratory and Critical Care Medicine, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250021, P.R. China