1. Department of Radiation Research for Environment and Resources, Takasaki Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute, Watanuki-machi 1233, Takasaki, Gunma 370–1292, Japan (A.T., A.S., G.S., Y.H., N.S., S.T., H.W.); and
2. Faculty of Pharmaceutical Science, Kanazawa University, Takaramachi 13–1, Kanazawa City, Kanazawa 920–0934, Japan (Y.I., O.N.)