1. Research Competency Milestones Program of School of Medicine, CHA University School of Medicine, Seongnam-si 13496, Republic of Korea
2. Department of Neurosurgery, CHA University School of Medicine, CHA Bundang Medical Center, Seongnam-si 13496, Republic of Korea
3. Department of Biomedical Science, Graduate School of CHA University, Seongnam-si 13496, Republic of Korea
4. Department of Medicine, Graduate School, Kyung Hee University, Seoul 02453, Republic of Korea
5. Department of Neurosurgery, Kangbuk Samsung Hospital, Sungkyunkwan University College of Medicine, Seoul 03181, Republic of Korea
6. Department of Neurosurgery, Kyung Hee University, Seoul 02453, Republic of Korea
7. Department of Otorhinolaryngology-Head and Neck Surgery, CHA University School of Medicine, CHA Bundang Medical Center, Seongnam-si 13496, Republic of Korea
8. Department of Microbiology, School of Medicine, CHA University, Seongnam-si 13496, Republic of Korea