Funding for this research was provided by:
National Research Foundation of Korea (No.2016M3A7B4910)
Text and Data Mining valid from 2018-04-24
Received: 18 January 2018
Accepted: 9 April 2018
First Online: 24 April 2018
Ethics approval and consent to participate
: All procedures involving human participants were performed in accordance with the ethical standards of the institutional research committee. The present study was approved by the Institutional Review Board of Seoul National University (IRB No. 1508/002-010).
: Informed consent was obtained from all participants in the study.
: The authors declare that they have no competing interests.
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