1. Department of Clinical Laboratory, Weihai Central Hospital, Weihai, Shandong 264400, P.R. China
2. Department of Blood Transfusion, Affiliated Hospital of Jining Medical University, Jining, Shandong 272000, P.R. China
3. Department of Medical Administration, Weihai Central Hospital, Weihai, Shandong 264400, P.R. China