Funding for this research was provided by:
Fundamental Research Funds for the Central Universities, and the Research Funds of Renmin University of China (18XNA009)
Article History
First Online: 21 September 2019
Compliance with Ethical Standards
:
: The authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee (Renmin University of China) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The ethics approval was obtained from The Ethics Review Board at Renmin University of China.
: Informed consent was obtained from all student participants and their parents included in the study.