1. Division of Surgery, Graduate Department, Weifang Medical College, Weifang, Shandong, People’s Republic of China
2. Department of Thoracic Surgery, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong, People’s Republic of China
3. Department of Thoracic Surgery, Shengli Oilfield Central Hospital, Dongying, Shandong, People’s Republic of China