1. Department of Urology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100730, P.R. China
2. Department of Urology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
3. School of Humanities and Social Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, P.R. China