1. Central
Research Laboratory, Hitachi Ltd. 1-280 Higashi-Koigakubo, Kokubunji, Tokyo 185-8601, Japan
2. Department
of Materials Engineering, Graduate School of Engineering, The University of Tokyo, 7-1-3 Hongo, Bunkyo, Tokyo 113-0033, Japan
3. Department
of Life Science and Medical Bioscience, Waseda University, 2-2
Wakamatsu-cho, Shinjuku, Tokyo 162-8480, Japan