Funding for this research was provided by:
Natural Science Foundation of Inner Mongolia (2016MS0366)
Text and Data Mining valid from 2019-11-15
Received: 28 June 2019
Accepted: 23 October 2019
First Online: 15 November 2019
Ethics approval and consent to participate
: Not applicable.
: All authors read the final manuscript and approved for publication.
: The authors declare that they have no competing interests.