Funding for this research was provided by:
Japan Society for the Promotion of Science (JP16H00518)
Received: 12 December 2018
Accepted: 21 February 2019
First Online: 12 March 2019
Ethics approval and consent to participate
: This study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of Tohoku University Graduate School of Medicine (No. 2011–634). A clear written consent was obtained from each patient prior to start of the study.
: Not applicable.
: The authors declare that they have no competing interests.
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