Funding for this research was provided by:
National Natural Science Foundation of China (81330065, 81673149)
Text and Data Mining valid from 2018-09-15
Received: 17 March 2018
Accepted: 14 August 2018
First Online: 15 September 2018
Ethics approval and consent to participate
: The study design was ethically approved by the Ethics Committee of Capital Medical University (2013SY35). All participants provided written informed consent at the beginning of the study.
: All the co-authors and participants have given their consent for publication.
: The authors declare that they have no competing interests.
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