Yang, Lijun
Fan, Yong
Lin, Ru
He, Wenlong
Article History
Received: 30 July 2018
Accepted: 5 December 2018
First Online: 2 January 2019
Compliance with Ethical Standards
:
: The authors 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 and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: The ethical standards of the institutional research committee granted permission to access and analyze the data with a waiver of informed consent because this is a retrospective analysis of the collected data.