1. Department of Clinical Laboratory, The First People's Hospital of Zibo City, Zibo, Shandong 255200, P.R. China
2. Department of Endocrinology, Stem Cell Research Center, The Affiliated Hospital of Medical College, Qingdao University, Qingdao, Shandong 266003, P.R. China
3. Biochemistry Office, Weifang Medical College, Weifang, Shandong 261042, P.R. China