Funding for this research was provided by:
The Humanity and Social Science Youth Foundation of the Ministry of Education in China (17YJC190002)
China Postdoctoral Science Foundation (2017M621508)
Article History
First Online: 5 September 2019
Compliance with Ethical Standards
:
: The authors declare that they have no conflict of interest.
: All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all participants and their parents.