Funding for this research was provided by:
National Natural Science Foundation of China (#31420103915, #81572769)
Natural Science Foundation of Chongqing (#2016ZDXM006)
Received: 12 January 2018
Accepted: 14 February 2018
First Online: 27 February 2018
Ethics approval and consent to participate
: This research was approved by the Institutional Ethics Committees of the First Affiliated Hospital of Chongqing Medical University (#20130306) and conformed to the tenets of the Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.
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