1. Graduate Institute of Biomedical Engineering, National Chung Hsing University, Taichung 402, Taiwan
2. Department of Anatomy, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
3. Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
4. Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan