Funding for this research was provided by:
Health and Family Planning Commission of Sichuan Province (ZH2018-102, 2018-116)
Article History
Received: 4 October 2018
Accepted: 21 November 2018
First Online: 11 December 2018
Compliance with ethical standards
:
: All authors have no conflict of interest to declare.
: All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This article does not contain any study with animals performed by any of the authors.
: Informed consent was obtained from all the participants in this study or their legal proxies.