Funding for this research was provided by:
Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (16K16572, 15H03100)
Received: 4 October 2017
Accepted: 14 February 2018
First Online: 21 February 2018
Ethics approval and consent to participate
: All subjects gave their written informed consent before enrolling in the study. The study was performed in accordance with the guidelines of the Declaration of Helsinki and was approved by the Ritsumeikan University’s Institutional Review Board (approval number: 2013-036), Kusatsu, Japan.
: All participants gave written informed consent for publication after a complete explanation of this study.
: The authors declare that they have no competing interests.
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