Funding for this research was provided by:
Japan Society for the Promotion of Science (16K10588)
Received: 1 February 2018
Accepted: 12 March 2019
First Online: 21 March 2019
Ethics approval and consent to participate
: This study was approved by the institutional review board of Hiroshima University (No. EKI-747). All study participants provided informed written consent prior to study enrollment.
: Not applicable.
: The authors declare that they have no competing interests.
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