Funding for this research was provided by:
the Luzhou city - Southwest Medical University Joint Project (2017LZXNYD-PO2)
PhD Research Fund of the Affiliated Hospital of Southwest Medical University, (16238)
Received: 5 March 2018
Accepted: 15 May 2018
First Online: 25 May 2018
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of The First Affiliated Hospital of Southwest Medical University, Luzhou city, China. Informed consent was obtained from each participant.
: All authors consent for publication.
: The authors declare that they have no competing interests.
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