Funding for this research was provided by:
National Research Foundation of Korea (2009-0093815, 2014R1A1A1006006)
Korea Health Industry Development Institute (HI17C0927)
Chungnam National University
Received: 21 August 2017
Accepted: 17 January 2018
First Online: 25 January 2018
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board in Chungnam National University (201701SB00301), and was performed under institutional guidelines.
: Not applicable.
: The authors declare that they have no competing interests.
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