Funding for this research was provided by:
National Basic Research Program of China (973 Program) (2016YFC0904503)
Text and Data Mining valid from 2019-12-01
Received: 27 March 2019
Accepted: 4 December 2019
First Online: 19 December 2019
Ethics approval and consent to participate
: This study has been approved by the Ethics Committee of the Second Hospital of Hebei Medical University. Written informed consent has been obtained from all patients or their legal surrogates.
: Not applicable.
: The authors declare that they have no competing interests.