1. Department of Thoracic Surgery, Sichuan Cancer Hospital and Research Institute, Chengdu, Sichuan 610041, P.R. China
2. Department of Clinical Medicine, North Sichuan Medical College, Nanchong, Sichuan 637000, P.R. China
3. Department of Respiratory Medicine, Nanchong Central Hospital, Nanchong, Sichuan 637000, P.R. China
4. Department of Anesthesiology, North Sichuan Medical College, Nanchong, Sichuan 637000, P.R. China