Funding for this research was provided by:
Project of Science and Technology Commission and National Health and Family Planning Commission in Yanpu District of Shanghai (YP15Q07)
Received: 6 February 2018
Accepted: 5 July 2018
First Online: 12 July 2018
Ethics approval and consent to participate
: The study protocol was approved by the Ethics Committees of the Tongji University Affiliated Yangpu Hospital, Shanghai. Informed consent was obtained from all individual participants included in the study.
: Not applicable.
: All authors declare that they have no competing interests.
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