Funding for this research was provided by:
Natural Science Foundation of Jiangsu Province (BK20171144, BK20161139)
Scientific Research Foundation of Jiangsu Provincial Commission of Health and Family Planning (H2018068)
Article History
Received: 7 April 2019
Accepted: 27 August 2019
First Online: 5 September 2019
Compliance with ethical standards
:
: The author(s) declare that they have no competing interests.