Funding for this research was provided by:
Jing'an District Health Bureau (JWRC2014G24)
Fudan University (2018A015)
Article History
Received: 8 January 2018
Accepted: 12 October 2018
First Online: 22 October 2018
Ethics approval and consent to participate
: The study protocol was approved by Fudan University research ethics committee. All participants provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.
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