1. Department of General Surgery, Second Hospital of Lanzhou University, Lanzhou, Gansu, 730000, China
2. College of Chemistry & Chemical Engineering, Lanzhou University, Lanzhou, 730000, China
3. Department of General Surgery, Xigu People’s Hospital, Lanzhou, Gansu, 730000, China
4. Department of Anorectal Surgery, Linxia People’s Hospital, Linxia, Gansu, 731100, China