1. Department of Nuclear Medicine Changhai Hospital Naval Medical University Shanghai 200433 P. R. China
2. University of Chinese Academy of Sciences Beijing 100049 P. R. China
3. State Key Laboratory of High Performance Ceramics and Superfine Microstructures Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 P. R. China
4. Tongji University Cancer Center Shanghai Tenth People's Hospital Tongji University School of Medicine Shanghai 200072 P. R. China
5. Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular Engineering East China Normal University Shanghai 200062 P. R. China