Funding for this research was provided by:
Korea University (Q1604581)
Received: 16 July 2018
Accepted: 31 October 2018
First Online: 5 December 2018
Ethics approval and consent to participate
: The study was approved by the Research and Ethical Review Committees at the Korea University Guro Hospital, Seoul, South Korea. Written informed consent was obtained from patients before enrollment into the study.
: Not applicable.
: The authors declare that they have no competing interests.
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