Funding for this research was provided by:
National Natural Science Foundation of China (81500988)
Article History
Received: 21 March 2018
Accepted: 5 August 2018
First Online: 13 August 2018
Compliance with ethical standards
:
: The authors declare that Doctor Peng Hu was sponsored by National Natural Science Foundation of China (Grant number of 81500988). Otherwise, there was no any conflict of interest to be declared.