Li, Pingfei
Zhang, Shiming
Sun, Wenliang
Cui, Mengsuo
Wen, Haoyang
Li, Qijun
Pan, Weisan
Yang, Xinggang
Article History
Received: 25 March 2019
Accepted: 12 June 2019
First Online: 24 June 2019
Compliance with Ethical Standards
: All procedures involving human participants in this study conformed to the ethical standards of the institutional and/or national research committee and complied with the 1964 Helsinki declaration and its later amendments and with other comparable ethical standards.
: The authors declare that they have no conflict of interest.