Funding for this research was provided by:
National Natural Science Foundation of China (82060601)
Yunnan Applied Basic Research Projects-Kunming Medical University Union Foundation (No. 2018FE001(-132))
Scientific Research Fund Project of Yunnan Provincial Department of Education (No. 2020Y116, No. 2018JS198)
NHC Key Laboratory of Drug Addiction Medicine (No. 2020DAMARA-006)
Top Young Talents of Yunnan Ten Thousand Talents Plan (No. YNWR-QNBJ-2018-286)
Innovative Research Team of Yunnan Province (202005AE160002)
Received: 12 September 2020
Accepted: 3 February 2021
First Online: 10 February 2021
Ethics approval and consent to participate
: This study was approved by the Ethics Review Board of Kunming Medical University. In addition, the participants or their legal guardians or teachers provided their written informed consent. In the case of boarding students, written informed consent was obtained from teachers, and this was also approved by the institutional review board prior to the commencement of the study. For day students, written informed consent was obtained from their parents or legal guardians.
: Not applicable.
: The authors declare that they have no competing interests.