Funding for this research was provided by:
National Natural Science Foundation of China (NFSC 81471658)
Sichuan Province Science and Technology Support Program (2017SZ0003)
Text and Data Mining valid from 2019-05-14
Received: 29 January 2019
Accepted: 28 April 2019
First Online: 14 May 2019
Ethics approval and consent to participate
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in the study.
: Not applicable.
: The authors declare that they have no competing interests.
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