1 Department of Nephrology, the First Hospital of HeBei Medical University, No.89 DongGang Road, ShiJiaZhuang, 050030, People's Republic of China.
2 Department of Nephrology, Peking Union Medical College Hospital, Beijing, 100010, People's Republic of China.
3 Department of Nephrology, the First Hospital of HeBei Medical University, No.89 DongGang Road, ShiJiaZhuang, 050030, People's Republic of China. nephrology2009@hotmail.com.