Funding for this research was provided by:
National Institute of General Medical Sciences (R01GM102943)
National Natural Science Foundation of China (81370296, 81370297, 81570303)
Article History
Received: 16 October 2017
Revised: 8 December 2017
Accepted: 17 December 2017
First Online: 27 December 2017
Compliance with ethical standards
:
: The authors declare that they have no competing interests.