Yamashita, Futoshi
Fukuyama, Eiichi
Mizoguchi, Kazuo
Takizawa, Shigeru
Xu, Shiqing
Kawakata, Hironori
Article History
Received: 23 April 2015
Accepted: 6 October 2015
First Online: 9 December 2015
Competing interests
: The authors declare no competing financial interests.