1. Children's Health Centre, Sichuan Provincial Maternity and Child Health Care Hospital, Chengdu, Sichuan Province, China
2. Department of Neonatology, Sichuan Provincial Maternity and Child Health Care Hospital, Chengdu, Sichuan Province, China
3. Department of Head and Neck Tumour Surgery, Hospital of Stomatology Sichuan University, Chengdu, Sichuan Province, China
4. Department of Pathology, Sichuan Provincial Maternity and Child Health Care Hospital, Chengdu, Sichuan Province, China