Funding for this research was provided by:
the China national 11th five-year scientific project (2006BA2A08)
A special fund to the local public health by China national fisical supplement
zhejiang medical and health science project (2013KYA091)
Received: 24 January 2018
Accepted: 6 December 2018
First Online: 10 January 2019
Ethics approval and consent to participate
: This study was approved by the ethics committee of the Second Affiliated Hospital, College of Medicine, Zhejiang University in 2006.
: Not applicable.
: The authors declare that they have no competing interest.
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