1. Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital Fudan University, Shanghai 200032, P.R. China
2. Liver Cancer Institute, Zhongshan Hospital Fudan University, Shanghai 200032, P.R. China
3. Department of Thoracic Surgery, Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
4. Department of Medical Affairs, Hebei Chest Hospital, Shijiazhuang, Hebei 050041, P.R. China