1. Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan, Photon Medical Research Center, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamastu, Shizuoka 431-3192, Japan, and Department of Bioengineering, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8501, Japan