1. Department of General Surgery, The Second Hospital of Jilin University, Changchun, Jilin 130041, P.R. China
2. Department of Gastrointestinal Surgery, The Second Hospital of Shandong University, Shandong 250000, P.R. China
3. Central Laboratory, The Second Hospital of Jilin University, Changchun, Jilin 130041, P.R. China