Funding for this research was provided by:
Ministry of Education – Kingdom of Saudi Arabi (NRF-2017S1A3A2067165)
Text and Data Mining valid from 2019-12-01
Received: 3 May 2019
Accepted: 16 December 2019
First Online: 23 December 2019
Ethics approval and consent to participate
: Ethical approval was obtained from the Institutional Review Board of Yonsei University (YUIRB-2011-012-01). Written informed consent was obtained from all participants.
: Not applicable.
: The authors declare that they have no competing interests.