Funding for this research was provided by:
Text and Data Mining valid from 2018-03-13
Received: 24 November 2016
Accepted: 7 March 2018
First Online: 13 March 2018
Ethics approval and consent to participate
: This work was approved by the Wonkwang Institutional Review Board (WKIRB-201605-SB-027). The study followed the guidelines of the World Medical Association Declaration of Helsinki (version 2008). Due to the nature of the data collected, the requirement for informed consent was waived.
: Not applicable.
: The authors declare that they have no competing interests.
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