Funding for this research was provided by:
National Research Foundation of Korea (NRF-2012S1A5B5A01025076)
Text and Data Mining valid from 2019-11-06
First Online: 6 November 2019
Compliance with ethical standards
: None of the authors on this paper has any conflict of interest to report.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.