1. Renal Division, Department of Medicine, Peking University First Hospital, Beijing, P.R. China;
2. Institute of Nephrology, Peking University, Beijing, P.R. China;
3. Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, P.R. China;
4. Department of Respiratory and Critical Care Medicine, Peking University First Hospital, Beijing, P.R. China;
5. Renal Division, Peking University International Hospital, Beijing, P.R. China