1. School of Basic Courses, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, P.R. China
2. School of Clinical Medicine, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, P.R. China
3. Department of Obstetrics, The Third Affiliated Hospital of Sun Yat‑sen University, Guangzhou, Guangdong 510630, P.R. China
4. Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology and Institute of Stomatological Research, Hospital of Stomatology, Sun Yat‑sen University, Guangzhou, Guangdong, 510055, P.R. China
5. Intensive Care Unit, Guangdong No. 2 Provincial People's Hospital, Guangzhou, Guangdong 510317, P.R. China