1. The First School of Clinical Medicine, Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
2. State Key Lab of Reproductive Medicine, Department of Urology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
3. Department of Urology, Suzhou Ninth People's Hospital, Soochow University, Suzhou, Jiangsu 215299, P.R. China