1. Medical Research and Laboratory Diagnostic Center, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250013, P.R. China
2. Department of Thoracic Surgery, Shangdong Public Health Clinical Center, Jinan, Shandong 250102, P.R. China
3. School of Medicine, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China