Funding for this research was provided by:
Yunnan Provincial Department of Education Research Fund ((No. 2015z089))
Program of Philosophy and Social Science Fundation of Yunnan Province
Text and Data Mining valid from 2018-08-14
Received: 13 September 2017
Accepted: 25 July 2018
First Online: 14 August 2018
Ethics approval and consent to participate
: This study was approved by the Ethical Committee of the Third Affiliated Hospital of Kunming Medical University. Its procedure followed the Declaration of Helsinki. All participants provided a written informed consent form prior to the study.
: Not applicable.
: The authors declare that they have no competing interests.
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