Matsumoto, Hidetaka
Mukai, Ryo
Morimoto, Masahiro
Tokui, Shunsuke
Kishi, Shoji
Akiyama, Hideo
Article History
Received: 11 January 2019
Revised: 18 February 2019
Accepted: 3 March 2019
First Online: 9 March 2019
Compliance with ethical standards
: All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study formal consent is not required.