1. Department of Urology, Affiliated Hospital of Chengdu University, Chengdu, Sichuan 610041, P.R. China
2. Department of Urology, University of Tübingen, D‑72070 Tübingen, Baden‑Württemberg, Germany
3. Central Laboratory, Affiliated Hospital of Chengdu University, Chengdu, Sichuan 610000, P.R. China
4. Department of Urology, Zunyi Medical University, Guiyang, Guizhou 563000, P.R. China
5. Department of Urology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, P.R. China