1. Department of Nephrology, Jining No. 1 People's Hospital, Jining, Shandong 272011, P.R. China
2. Department of Nephropathy and Diabetes Mellitus, Baoji Central Hospital, Baoji, Shaanxi 721008, P.R. China
3. Department of Urology, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China