Funding for this research was provided by:
Pediatric Clinical Research Center Foundation of Sichuan Province, China (No.2017-46-4)
the Fundamental Research Funds for Central Universities (No.2012017yjsy196)
Research development project of Sichuan Provincial Science and Technology Department (No.2018SZ0130)
Text and Data Mining valid from 2019-11-18
Received: 11 June 2019
Accepted: 10 October 2019
First Online: 18 November 2019
Ethics approval and consent to participate
: This study protocol was approved by the Ethical Committee of West China Second University Hospital, Sichuan University. Written informed consent was obtained from guardians of participants prior to study enrollment.
: Not applicable
: The authors declare that they have no competing interests.