Article History
Received: 5 December 2017
Accepted: 1 February 2019
First Online: 12 February 2019
Ethics approval and consent to participate
: The study was deemed exempt from review by the Ethics Committee of the First Affiliated Hospital of Xi’an Jiaotong University as routine data for clinical purpose were used and all the information of patients was kept confidential in the study.
: Not applicable.
: LW, KHZ, WC, YY and SFF declare that they have no competing interests.
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