Funding for this research was provided by:
Kyoto University (Grant of Frontier Researches in Sustainable Humanosphere (Project No.2))
Text and Data Mining valid from 2018-03-12
Received: 20 December 2017
Accepted: 27 February 2018
First Online: 12 March 2018
Ethics approval and consent to participate
: All of the subjects gave their informed consent to participate after agreeing with purpose, methods, and significance of the study. The study conformed to the Declaration of Helsinki guidelines and was approved by the ethics Committee of Kyoto University (H24-1).
: Not applicable.
: The authors declare that they have no competing interests.
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