Funding for this research was provided by:
China Academy of Engineering (2013-XZ-21-3, 2014-ZD-09)
China Medical Board (11-083)
Text and Data Mining valid from 2018-05-31
Received: 21 February 2018
Accepted: 24 May 2018
First Online: 31 May 2018
Ethics approval and consent to participate
: Not applicable. Permission was obtained from the Ministry of Education of People’s Republic of China to access the data.
: The author(s) declare that they have no competing interests.
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