Funding for this research was provided by:
National Research Foundation of Korea (NRF-2017R1C1B5017705)
Received: 30 October 2017
Accepted: 28 December 2017
First Online: 16 January 2018
Ethics approval and consent to participate
: The present study was approved by the Institutional Review Board of the School of Medicine, CHA University, and informed consent was obtained from all participants.
: The approval of the Institutional Review Board included the consent for publication of any individual data.
: The authors declare that they have no competing interests.
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