1. Department of Biomolecular Engineering,
Graduate School of Engineering, Tohoku University, Aoba 6-6-11, Aramaki,
Aoba-ku, Sendai 980-8579, Japan
2. Center for Interdisciplinary
Research, Tohoku University, Sendai, Aoba 6-3, Aramaki, Aoba-ku, Sendai
980-8578, Japan