Funding for this research was provided by:
Yonsei University (Yonsei University Research Grant of 2020)
Article History
Accepted: 4 November 2020
First Online: 11 November 2020
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: Ethical approval was obtained from the Institutional Review Board, Yonsei University (7001988-201807-HR-425-01E) and it is certified that the study was performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.