Funding for this research was provided by:
National Natural Science Foundation of China (No. 81673236)
The Fourth Round of Three-Year Public Health Action Plan of Shanghai, China (No.15GWZK0101)
Text and Data Mining valid from 2018-03-14
Received: 31 July 2017
Accepted: 30 January 2018
First Online: 14 March 2018
Ethics approval and consent to participate
: This study was evaluated and approved by the Ethics Review Committee of the Ethical Institute of the School of Public Health, Fudan University (IRB#2015-TYSQ-03-30).
: Not applicable.
: The authors declare that they have no competing interests.
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