1. Medical Record Room, Weifang People's Hospital, Weifang, Shandong 261041, P.R. China
2. Department of Weifang City Disinfection Supply Quality Control Center, Weifang People's Hospital, Weifang, Shandong 261041, P.R. China
3. Department of General Surgery, Weifang People's Hospital, Weifang, Shandong 261041, P.R. China