Funding for this research was provided by:
Fundamental Research Funds for the Central Universities (2018YJS093)
National Natural Science Foundation of China (71621001)
Key research and development project of Shandong Province (2016GGX105004)
Text and Data Mining valid from 2018-10-24
Received: 3 January 2018
Accepted: 11 October 2018
First Online: 24 October 2018
: The authors declare that they have no competing interests.
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