Funding for this research was provided by:
Natural Science Foundation of Beijing Municipality (Grant No. 5184034)
National Natural Science Foundation of China (Grant No. 31771378)
National Natural Science Foundation of China (Grant No. 31800029)
National Natural Science Foundation of China (Grant No. 31470206)
Article History
Received: 19 October 2018
Revised: 18 December 2018
Accepted: 20 December 2018
First Online: 26 January 2019
Compliance with ethical standards
:
: The authors declare that they have no competing interests.
: This article does not contain any studies with human participants or animals performed by any of the authors.