1. Department of Pathology, Hebei Medical University, Key Laboratory of Kidney Diseases of Hebei Province, Shijiazhuang, Hebei 050017, P.R. China
2. Department of Pathology, The Third Affiliated Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, P.R. China
3. Department of Hospital Infection Control, Department of Public Health, Hebei General Hospital, Shijiazhuang, Hebei 050051, P.R. China