Funding for this research was provided by:
This research is funded by Vietnam National Foundation for Science and Technology Development (grant number 106-NN.02-2013.37.)
Article History
Received: 27 February 2018
Accepted: 31 May 2018
First Online: 27 July 2018
Compliance with ethical standards
:
: The authors declare no competing interests.
: This article does not contain any studies with human participants or animals performed by any of the authors.