Funding for this research was provided by:
National Social Science Fund of China (13CYY027)
Fundamental Research Funds for the Central Universities (15000-31620003)
Article History
First Online: 6 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 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 individual participants included in the study.