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 (17K16694)
Received: 2 July 2018
Accepted: 31 July 2018
First Online: 8 August 2018
Ethics approval and consent to participate
: This study was approved by the research board of Tokushima University Hospital (reference no. 2258).
: Not applicable.
: The authors declare that they have no competing interests.
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