Funding for this research was provided by:
National Natural Science Foundation of China (81660080)
Science and Technology Bureau, Guiyang Municipal Government (29-5-2017)
Text and Data Mining valid from 2018-11-20
Received: 17 August 2018
Accepted: 13 November 2018
First Online: 20 November 2018
Ethics approval and consent to participate
: This study was approved by the Research Ethics Committee of Guizhou Provincial People’s Hospital. The requirement for informed consent was waived because the data were anonymous.
: Not applicable.
: All authors declare that they have no competing interests.
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