Funding for this research was provided by:
the National key research and development program of China (No. 2016YFC0107105)
the Science and Technology Development of Shaanxi Province (No. 2014JZ2-007, 2015kw-039)
Innovation and Development Foundation of Tangdu Hospital (No. 2016LCYJ001)
Text and Data Mining valid from 2020-02-07
Received: 18 April 2019
Accepted: 13 January 2020
First Online: 7 February 2020
Ethics approval and consent to participate
: This is a retrospective study that does not require the approval of the ethics committee. (Not applicable).
: Our manuscript does not contain any individual person’s data. (Not applicable).
: The authors declare that they have no competing interests.