1. Department of Anesthesiology, Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University, Shenzhen, Guangdong 518000, P.R. China
2. Shenzhen Blood Center, Shenzhen, Guangdong 518000, P.R. China
3. Shenzhen Health Development Research Center, Shenzhen, Guangdong 518000, P.R. China