1. Medical School of Chinese PLA, Beijing, China
2. Department of Neonatology and NICU, Beijing Chaoyang District Maternal and Child Healthcare Hospital, Beijing, China
3. Department of Neonatology, Fifth Medical Center of Chinese, PLA General Hospital, Beijing, China
4. Neonatal Intensive Care Unit, Affiliated Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University, Beijing, China