Funding for this research was provided by:
National Natural Science Foundation of China (81370698, 81671488)
Beijing Municipal Natural Science Foundation (7162152)
Article History
Received: 27 January 2018
Accepted: 28 February 2018
First Online: 6 March 2018
Compliance with ethical standards
:
: Hongjun Li has received research grants from National Natural Science Foundation of China (81370698 and 81671488) and Beijing Natural Science Foundation (Grant No. 7162152).
: Human participants For this type of study formal consent is not required. Animals This article does not contain any studies with animals performed by any of the authors.
: Informed consent was obtained from all individual participants included in the study.