Funding for this research was provided by:
the grants from the Key Project of Education Department of Sichuan Province, China (17ZA0172)
the grants from the Cooperative Project of Scientific Research between Nanchong city and North Sichuan Medical College, P. R. China (NSMC20170403)
Text and Data Mining valid from 2018-05-10
Received: 1 October 2017
Accepted: 26 April 2018
First Online: 10 May 2018
Ethics approval and consent to participate
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