Association of urinary and seminal plasma vanadium concentrations with semen quality: A repeated-measures study of 1135 healthy men oleh Heng-Gui Chen, Ping Wu, Xiao-Feng Zheng, Qing-Ling Su, Qiao-Fen Lin, Bin Sun, Ying-Jun Chen, Tian-Qing Meng, Cheng-Liang Xiong, An Pan, Yi-Xin Wang, Weimin Ye