Funding for this research was provided by:
National Science Foundation of China (NSFC 81770342)
Nanjing Health and Family Planning Commission (YKK16124)
Nanjing health youth talent training project (QRX17017)
Nanjing Municipal Commission of Science & Technology (201715026)
Text and Data Mining valid from 2018-05-24
Received: 12 March 2018
Accepted: 18 May 2018
First Online: 24 May 2018
Ethics approval and consent to participate
: The study was approved by the institutional ethics committee of Nanjing First Hospital, and was carried out in accordance with the guidelines of the Declaration of Helsinki. Written informed consent was formally obtained from all participants.
: The authors declare that they have no competing interests.
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