This book is based on two keywords: Bioradical and ESR. Bioradical is a newly coined word which encompasses paramagnetic species in biological systems, such as active oxygen radicals and transition metal ions. Research on the structure and function of bioradicals has been attrac ting growing attention in the field of biological science, and comprehensive investigations from many fields are helping to understand the real features of these species. ESR spectroscopy also has interdisciplinary features in that its techniques have been applied to many fields, ranging from physics to medicine. It...