1 Department of Nephrology, The Fourth Hospital of Hebei Medical University, Hebei Clinical Research Center for Chronic Kidney Disease, Hebei Key Laboratory of Vascular Calcification in Kidney Disease, Shijiazhuang, P. R. China.
2 Department of Nephrology, The Fourth Hospital of Hebei Medical University, Hebei Clinical Research Center for Chronic Kidney Disease, Hebei Key Laboratory of Vascular Calcification in Kidney Disease, Shijiazhuang, P. R. China. xjs5766@126.com.