Zhang, Lei
Zuo, Yu-Ming
Huo, Yong-Xin
Wang, Guo-Qiang
Zhang, Liu
Article History
Received: 6 November 2018
Accepted: 18 February 2019
First Online: 26 February 2019
Ethics approval and consent to participate
: This study follows verbal consent from Institutional Review Board of Hebei Medical University. As this study has a retrospective design, the need for informed consent was waived by the Institutional Review Board.
: Not applicable
: The authors declare that they have no competing interests.
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