Funding for this research was provided by:
National Natural Science Foundation of China (81741026, 81571515, 81800288)
Science-technology Support Plan Projects in Sichuan province (2019YFS0243, 2017SZ0117)
Technology Innovation Research and Development Project of Chengdu Science and Technology Bureau (2018-YF05-00249-SN)
Received: 2 January 2020
Accepted: 3 July 2020
First Online: 14 July 2020
Ethics approval and consent to participate
: Written informed consent was obtained from the parents following a full explanation of the nature of the study. The University Ethics Committee on Human Subjects at Sichuan University approved the study.
: Written consent obtained.
: None of authors declared any conflict of interests.