1. Renal Division, Department of Medicine, Peking University First Hospital, Beijing 100034, P.R. China
2. State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P.R. China
3. Institute of Nephrology, Peking University, Beijing 100034, P.R. China