Guo, Yunfei
Huang, Xiting
Article History
First Online: 2 May 2019
Compliance with Ethical Standards
: The study was approved by the Ethics Committee of Southwest University and all the participants needed to sign the informed consent form.
: All procedures performed in the present study involving humanparticipants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinkideclaration and its later amendments or comparable ethical standards.
: We have no conflict of interest in the present study.