Article History
Received: 26 August 2020
Accepted: 15 February 2021
First Online: 25 February 2021
Ethics approval and consent to participate
: This study was performed in strict accordance with the human subject protection guidance of Ministry of Science and Technology of China, and the study protocol was approved by the Ethical Review Committee of Shenzhen Children’s Hospital with judgment’s reference number 201907903. Written consent was obtained from the guardians of all participants before data collection.
: Not applicable.
: The authors have no potential conflicts of interest.