Funding for this research was provided by:
National Natural Science Foundation of China (81700451, 81771620)
Beijing Municipal Administration of Hospitals Incubating Program (PX2020054)
Chinese Academy of Medical Sciences Initiative for Innovative Medicine (CAMS-I2M)
Received: 25 February 2020
Accepted: 15 June 2020
First Online: 22 June 2020
Ethics approval and consent to participate
: This study was approved by the medical ethics committee of the Capital Institute of Pediatrics (SHERLL 2019049) and was carried out according to the Declaration of Helsinki. All caregivers and participants (when able) provided written informed consent.
: Written informed consents for publication were obtained from all caregivers.
: The authors declare that they have no competing interests.