1. Department of Clinical Laboratory, Binzhou City Center Hospital, Binzhou, Shandong 251700, P.R. China
2. Department of Obstetrics, Binzhou City Center Hospital, Binzhou, Shandong 251700, P.R. China
3. Department of Hemodialysis Room, Binzhou City Center Hospital, Binzhou, Shandong 251700, P.R. China
4. Department of Medical Laboratory, Jining First People's Hospital, Jining, Shandong 272111, P.R. China