Funding for this research was provided by:
National Special Science and Technology Project for Major Infertious Diseases of China (No.2018ZX10101002-002,2012ZX10004-220, 2016YFC1202000)
Text and Data Mining valid from 2019-06-18
Received: 16 January 2019
Accepted: 28 May 2019
First Online: 18 June 2019
: This study has been reviewed and approved by the Institutional Review Board of Chinese Center for Disease Control And Prevention (Approval No. 201818). The study does not onvolve the use of any animal or human samples.
: The authors declare that they have no competing interests.