Funding for this research was provided by:
National Natural Science Foundation of China (No.81500129, No.81572060)
Text and Data Mining valid from 2019-05-28
Received: 19 February 2019
Accepted: 13 May 2019
First Online: 28 May 2019
Ethics approval and consent to participate
: The research conformed to the standard stipulated by Declaration of Helsinki and was performed with the approval of the ethical committee of Chongqing Medical University.
: Not applicable.
: The authors declare that they have no competing interest.
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