Funding for this research was provided by:
Natural Science Foundation of Hunan Province (2016JJ2106)
Text and Data Mining valid from 2020-02-03
Received: 5 December 2019
Accepted: 21 January 2020
First Online: 3 February 2020
Ethics approval and consent to participate
: All patients in this study gave informed consent.
: Not applicable.
: The authors declare that they have no competing interests.