1. Renal Division, Department of Medicine; People's Hospital of Guizhou Province,Guiyang; Guizhou 55002 China
2. Department of Diagnostics; Medical College of Guizhou University; Guiyang Guizhou 550002 China
3. Medical College of Guizhou University; Guiyang Guizhou 550002 China
4. Department of Clinical Education; People's Hospital of Guizhou Province; Guiyang Guizhou 550002 China