Funding for this research was provided by:
National Natural Science Foundation of China (No.81070885, No. 81471126)
Foundation of the Science and Technology Department of Zhejiang Province of China (No2014c33171)
Text and Data Mining valid from 2018-07-03
Received: 4 January 2018
Accepted: 22 June 2018
First Online: 3 July 2018
Ethics approval and consent to participate
: The study protocol was approved by the local Research Ethics Committee of the Women’s Hospital, School of Medicine, Zhejiang University and written informed consent was obtained from all patients who participated in the study.
: Not applicable.
: The authors declare that they have no competing interests.
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