Wakamura, T.
Akaike, H.
Omori, Y.
Niimi, Y.
Takahashi, S.
Fujimaki, A.
Maekawa, S.
Otani, Y.
Article History
Received: 30 September 2014
Accepted: 26 March 2015
First Online: 18 May 2015
Competing interests
: The authors declare no competing financial interests.