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, Grant No. 31800029, 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.