1. Center for Molecular Imaging and Translational Medicine; State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics; School of Public Health; Xiamen University; Xiamen 361102 P. R. China
2. Zhongshan Hospital Affiliated of Xiamen University; Xiamen 361004 P. R. China
3. Laboratory of Molecular Imaging and Nanomedicine (LOMIN); National Institute of Biomedical Imaging and Bioengineering (NIBIB); National Institutes of Health (USA); Bethesda Maryland 20892 USA