1. Department of Emergency Respiratory, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116001, P.R. China
2. Department of Pathology and Pathophysiology, School of Medicine, Xi'an Jiaotong University, Xian, Shanxi 710049, P.R. China
3. Department of Pathology and Pathophysiology, Dalian Medical University, Dalian, Liaoning 116023, P.R. China
4. Department of Thoracic Surgery, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116001, P.R. China