Takahashi, Riku
Wu, Zi Liang
Arifuzzaman, Md
Nonoyama, Takayuki
Nakajima, Tasuku
Kurokawa, Takayuki
Gong, Jian Ping
Article History
Received: 20 December 2013
Accepted: 24 June 2014
First Online: 8 August 2014
Competing interests
: The authors declare no competing financial interests.