Funding for this research was provided by:
Beijing Municipal Administration of Hospitals’ Youth Program (QML 20150904)
Received: 9 July 2020
Accepted: 22 September 2020
First Online: 6 October 2020
Ethics approval and consent to participate
: This study was approved by the human research ethic committees of Beijing Hospital of Traditional Chinese Medicine. Written informed consent was obtained from the parents/guardians.
: Written informed consent was obtained from the parents/guardians for the publication of this study.
: The authors declare that they have no competing interests.