Funding for this research was provided by:
Shandong Education Department (J17RA137)
Science and Technology Development Plan of Weifang (2015WS009, 2018YX003)
Health and Family Planning Commission of Sichuan Province (2017WS852)
Natural Science Foundation of Shandong Province (ZR2016GM05)
Article History
Received: 9 August 2019
Accepted: 30 October 2019
First Online: 18 November 2019
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: All procedures in studies involving human participants were conducted in accordance with the ethical standards of the Southern Adelaide Clinical Human Research Ethics Committee and with the 1964 Helsinki declaration and its later amendments or comparable ethicalstandards.
: Informed consent was obtained from all individual participants included in the study.