Senga, Ryosuke
Komsa, Hannu-Pekka
Liu, Zheng
Hirose-Takai, Kaori
Krasheninnikov, Arkady V.
Suenaga, Kazu
Article History
Received: 24 April 2014
Accepted: 28 July 2014
First Online: 14 September 2014
Competing interests
: The authors declare no competing financial interests.