Showing papers by "Jin Hyung Lee published in 2006"
TL;DR: A scalable chemical vapour deposition method is presented to synthesize FeCo/single-graphitic-shell nanocry crystals that are soluble and stable in water solutions and point to the potential of using these nanocrystals for integrated diagnosis and therapeutic (photothermal-ablation) applications.
Abstract: Nanocrystals with advanced magnetic or optical properties have been actively pursued for potential biological applications, including integrated imaging, diagnosis and therapy. Among various magnetic nanocrystals, FeCo has superior magnetic properties, but it has yet to be explored owing to the problems of easy oxidation and potential toxicity. Previously, FeCo nanocrystals with multilayered graphitic carbon, pyrolytic carbon or inert metals have been obtained, but not in the single-shelled, discrete, chemically functionalized and water-soluble forms desired for biological applications. Here, we present a scalable chemical vapour deposition method to synthesize FeCo/single-graphitic-shell nanocrystals that are soluble and stable in water solutions. We explore the multiple functionalities of these core-shell materials by characterizing the magnetic properties of the FeCo core and near-infrared optical absorbance of the single-layered graphitic shell. The nanocrystals exhibit ultra-high saturation magnetization, r1 and r2 relaxivities and high optical absorbance in the near-infrared region. Mesenchymal stem cells are able to internalize these nanoparticles, showing high negative-contrast enhancement in magnetic-resonance imaging (MRI). Preliminary in vivo experiments achieve long-lasting positive-contrast enhancement for vascular MRI in rabbits. These results point to the potential of using these nanocrystals for integrated diagnosis and therapeutic (photothermal-ablation) applications.
814 citations
TL;DR: Structurally, this protein is distinct from all other known PRMTs implying that convergent evolution allowed this protein to develop the ability to methylate arginine residues and evolved elements conserved inPRMTs to accomplish this.
144 citations
01 Jan 2006
TL;DR: In this paper, Santos et al. presented an extension using multiple acquisition coils with localized sensitivity demodulation to improve the SNR and volumetric coverage of a single breath-hold whole heart acquisition method.
Abstract: J. M. Santos, B. S. Hu, J. H. Lee, J. M. Pauly Electrical Engineering, Stanford University, Stanford, California, United States, Cardiovascular Medicine, Palo Alto Medical Foundation, Palo Alto, California, United States Introduction: We have previously demonstrated a single breath-hold whole-heart acquisition method using variable density spirals [1]. Taking advantage of the restricted FOV created by the sensitivity profile of a surface coil, controlled undersampling can reduce the acquisition time without introducing coherent aliasing artifacts. One important characteristic of the previously presented method is that it acquires the volumetric data in a multislice fashion with an ultra short acquisition widow (less than 6 ms). This provides great immunity to motion. In this abstract we present an extension using multiple acquisition coils with localized sensitivity demodulation to improve the SNR and volumetric coverage.
2 citations