Funding for this research was provided by:
National Natural Science Foundation of China (81400862, 81401606)
Key Project in the Science & Technology Program of Sichuan Province (2019YFS0322)
Science Foundation for The Excellent Youth Scholars of Sichuan University (2015SU04A15)
Article History
Received: 26 August 2019
Accepted: 13 September 2019
First Online: 29 October 2019
Ethics approval and consent to participate
: The study was approved by the Ethics Committee of the West China Hospital of Sichuan University. Informed consents were obtained from the legal guardians of the children included in the study.
: Not applicable.
: The authors declare that they have no competing interests.