Takehara, Hiroaki
Nagaoka, Akira
Noguchi, Jun
Akagi, Takanori
Kasai, Haruo
Ichiki, Takanori
Article History
Received: 8 July 2014
Accepted: 3 October 2014
First Online: 22 October 2014
Competing interests
: The authors declare no competing financial interests.