1. Department of Nursing Science, Suwon University, Gyeonggi 447-743, Korea.
2. College of Nursing & Research Institute of Nursing Science, Seoul National University, 103 Daehak-ro, Jongro-Gu, Seoul 110-799, Korea.
3. Nutritional Science, Department of Agriculture and Natural Resources, Michigan State University 48109, USA.
4. Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.