Funding for this research was provided by:
Soft Science Research Program in Shanxi (2017041039-2)
Research Project Supported by Shanxi Scholarship Council of China (2017-062)
Fund Program for the Scientific Activities of Selected Returned Overseas Professional in Shanxi Province (2017-16)
National Natural Science Foundation of China (71403155)
Received: 9 September 2018
Accepted: 9 January 2019
First Online: 21 January 2019
Ethics approval and consent to participate
: All study procedures were approved by the Ethic Committee of Shanxi Medical University.
: No applicable
: The authors declare that they have no competing interests.
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