1. National Creative Research Initiative Center for Oxide Nanocrystalline Materials, World Class University (WCU) Program of Chemical Convergence for Energy & Environment (C2E2), and School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Korea
2. Radiology, Seoul National University Hospital, and the Institute of Radiation Medicine, Medical Research Center, Seoul National University, 28, Yeongeon-dong, Jongno-gu, Seoul 110-744, Korea
3. Department of Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Suwon 443-270, Korea