1. School of Materials Science and the 21st COE Program, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan, Institute of Materials and Chemical Engineering, Kyushu University, Hakozaki, Fukuoka 812-8581, Japan, and Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Sapporo 060-0812, Japan