1. Shaanxi Provincial Key Laboratory of Infection and Immune Diseases, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
2. Information Department, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
3. Department of Medical Records, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
4. Second Department of General Surgery, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China