1. School of Clinical and Basic Medical Sciences, Shandong First Medical University, Jinan, Shandong 250117, P.R. China
2. Department of Thoracic Surgery, Jinan Central Hospital, Shandong University, Jinan, Shandong 250013, P.R. China
3. Department of General Surgery, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250014, P.R. China