Funding for this research was provided by:
National Natural Science Foundation of China (31571277, 30971570)
Natural Science Foundation of Ningxia Province (2017JJ2109, 2017JJ2104)
Text and Data Mining valid from 2019-02-28
Received: 20 December 2018
Accepted: 24 January 2019
First Online: 28 February 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: All animal handling complied with the requirements of the directory of the Ethical Treatment of Experimental Animals of China.