1. Research Institute for Biomedical Science, Tokyo University of Science, 2669 Yamazaki, Noda, Chiba 278-0022 Japan
2. Division of Functional Imaging, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, 6-5-1 Kashiwanoha, Kashiwa 277-8577, Japan
3. Department of Material Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan