1. Key Laboratory of Evidence Science, China University of Political Science and Law, Ministry of Education, Beijing 100088, P.R. China
2. Central Laboratory, The Second Affiliated Hospital of Xi'an Medical College, Xi'an, Shaanxi 710038, P.R. China
3. Institute of Forensic Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China
4. Department of Obstetrics and Gynecology, North District of Suzhou Municipal Hospital, Suzhou, Jiangsu 215000, P.R. China