Funding for this research was provided by:
Ministry of Health, Labour and Welfare
Received: 14 May 2018
Accepted: 17 July 2018
First Online: 22 August 2018
Ethics approval and consent to participate
: The ethical approval for the animal experiment was obtained from the institutional animal ethics committee before conducting the experiment. Animal experiment has been done following the guidance provided by the committee, with a careful attention to animal welfares. No human subject was used.
: Not applicable.
: The authors declare that they have no competing interests.
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