1. Department of Obstetrics and Gynaecology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
2. College of Medical Technology, Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China
3. Department of Basic Medicine School, Qiqihar Medical University, Qiqihar 161006, P.R. China
4. School of Medicine and Health, Harbin Institute of Technology, Harbin, Heilongjiang 150001, P.R. China
5. Department of Psychiatry, Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China