Received: 26 November 2017
Accepted: 17 January 2018
First Online: 25 January 2018
Ethics approval and consent to participate
: The study protocols were approved by the Ethical Committee at the Second Affiliated Hospital of Xi’an Jiaotong University (No. 2017023). The written informed consent was obtained from each participant.
: Not Applicable.
: The authors declare that they have no competing interests.
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