1. Department of Thoracic Surgery, The Second People's Hospital of Liaocheng, Linqing, Shandong 252600, P.R. China
2. Department of Urology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
3. Department of Geriatrics Nephrology, Linqing People's Hospital, Linqing, Shandong 252600, P.R. China