Funding for this research was provided by:
National Research Foundation of Korea (NRF-2016R1C1B1007909)
Received: 1 October 2017
Accepted: 18 January 2018
First Online: 25 January 2018
: The International Review Board for Human Research of Yonsei University Wonju College of Medicine approved this study (CR315005–002). Written informed consent was obtained from all patients.
: Not applicable
: The authors declare that they have no competing interests.
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