Daegu, South Korea
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Xu W.,Kyungpook National University | Bony B.A.,Kyungpook National University | Kim C.R.,Kyungpook National University | Baeck J.S.,KNU and Hospital | And 4 more authors.
Scientific Reports | Year: 2013

There is no doubt that the molecular imaging is an extremely important technique in diagnosing diseases. Dual imaging is emerging as a step forward in molecular imaging technique because it can provide us with more information useful for diagnosing diseases than single imaging. Therefore, diverse dual imaging modalities should be developed. Molecular imaging generally relies on imaging agents. Mixed lanthanide oxide nanoparticles could be valuable materials for dual magnetic resonance imaging (MRI)-fluorescent imaging (FI) because they have both excellent and diverse magnetic and fluorescent properties useful for dual MRI-FI, depending on lanthanide ions used. Since they are mixed nanoparticles, they are compact, robust, and stable, which is extremely useful for biomedical applications. They can be also easily synthesized with facile composition control. In this study, we explored three systems of ultrasmall mixed lanthanide (Dy/Eu, Ho/Eu, and Ho/Tb) oxide nanoparticles to demonstrate their usefulness as dual T 2 MRI-FI agents.

Ahmad M.W.,Kyungpook National University | Kim C.R.,Kyungpook National University | Bae J.E.,KNU | Chae K.S.,KNU | And 2 more authors.
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2014

Bovine serum albumin (BSA) (Mn=66.5kD, size=14×4×4nm) is an attractive biological molecule for biomedical applications because of its water-solubility and bio-compatibility. It can also bind many ultrasmall nanoparticles (NPs) as confirmed in this study. We synthesized polyethylene glycol diacid (PEGD) coated ultrasmall Gd2O3 nanoparticles (PEGD-GNPs, the core davg=2.0nm), which were then conjugated to BSA and cleaved-BSA (C-BSA) (i.e. BSA-PEGD-GNPs and C-BSA-PEGD-GNPs) through amide bonding. Large relaxivities were observed in both aqueous sample solutions (r1=6.0s-1mM-1 and r2=28.0s-1mM-1 for BSA-PEGD-GNPs and r1=7.6s-1mM-1 and r2=22.0s-1mM-1 for C-BSA-PEGD-GNPs). Three tesla T2 magnetic resonance imaging (MRI) in a mouse after the injection of an aqueous sample solution of BSA-PEGD-GNPs into a mouse tail vein revealed significant negative contrast enhancements. Large relaxivities and in vivo MR images prove that BSA-PEGD-GNPs and C-BSA-PEGD-GNPs are potential MRI contrast agents. © 2014 Elsevier B.V.

Jung H.,ETRI | Gohar M.,KNU | Kim J.-I.,KNU | Koh S.-J.,KNU
IEICE Transactions on Communications | Year: 2011

In future mobile networks, the ever-increasing loads imposed by mobile Internet traffic will force the network architecture to be changed from hierarchical to flat structure. Most of the existing mobility protocols are based on a centralized mobility anchor, which will process all control and data traffic. In the flat network architecture, however, the centralized mobility scheme has some limitations, such as unwanted traffic flowing into the core network, service degradation by a single point of failure, and increased operational costs, etc. This paper proposes mobility schemes for distributed mobility control in the flat network architecture. Based on the Proxy Mobile IPv6 (PMIP), which is a well-known mobility protocol, we propose the three mobility schemes: Signal-driven PMIP (S-PMIP), Data-driven Distributed PMIP (DD-PMIP), and Signal-driven Distributed PMIP (SD-PMIP). By numerical analysis, we show that the proposed distributed mobility schemes can give better performance than the existing centralized scheme in terms of the binding update and packet delivery costs, and that SD-PMIP provides the best performance among the proposed distributed schemes. © 2011 The Institute of Electronics, Information and Communication Engineers.

PubMed | Kyungpook National University, KNU, Teachers College and Korea Institute of Radiological and Medical Sciences
Type: | Journal: Scientific reports | Year: 2015

Gadolinium (Gd) is a unique and powerful element in chemistry and biomedicine which can be applied simultaneously to magnetic resonance imaging (MRI), X-ray computed tomography (CT), and neutron capture therapy for cancers. This multifunctionality can be maximized using gadolinium oxide (Gd2O3) nanoparticles (GNPs) because of the large amount of Gd per GNP, making both diagnosis and therapy (i.e., theragnosis) for cancers possible using only GNPs. In this study, the T1 MRI and CT dual imaging capability of GNPs is explored by synthesizing various iodine compound (IC) coated GNPs (IC-GNPs). All the IC-GNP samples showed stronger X-ray absorption and larger longitudinal water proton relaxivities (r1 = 26-38s(-1) mM(-1) and r2/r1 = 1.4-1.9) than the respective commercial contrast agents. In vivo T1 MR and CT images of mice were also acquired, supporting that the GNP is a potential dual imaging agent.

Kim C.R.,Kyungpook National University | Baeck J.S.,KNU and Hospital | Chang Y.,KNU and Hospital | Bae J.E.,KNU | And 3 more authors.
Physical Chemistry Chemical Physics | Year: 2014

The dependence of longitudinal (r1) and transverse (r 2) water proton relaxivities of ultrasmall gadolinium oxide (Gd 2O3) nanoparticles on the surface coating ligand-size was investigated. Both r1 and r2 values decreased with increasing ligand-size. We attributed this to the ligand-size effect. In addition the effectiveness of d-glucuronic acid-coated ultrasmall Gd 2O3 nanoparticles as T1 magnetic resonance imaging (MRI) contrast agents was confirmed by measuring the in vitro cytotoxicity and using in vivo T1 MR images in a mouse in a 1.5 T MR field. © the Partner Organisations 2014.

Bony B.A.,Kyungpook National University | Baeck J.S.,KNU and Hospital | Chang Y.,KNU and Hospital | Bae J.E.,KNU | And 3 more authors.
Biomaterials Science | Year: 2014

Ultrasmall lanthanide oxide nanoparticles are promising materials as new magnetic resonance imaging (MRI) contrast agents because of their appreciable longitudinal (r1) or transverse (r2) water proton relaxivities at ultrasmall particle diameters. Two systems of d-glucuronic acid coated ultrasmall Ln/Mn (Ln = Gd and Dy) oxide nanoparticles with an average particle diameter of 2.0 nm were explored. The d-glucuronic acid coated ultrasmall Gd/Mn oxide nanoparticles showed strong positive contrast enhancements in 1.5 tesla T1 MR images while the d-glucuronic acid coated ultrasmall Dy/Mn oxide nanoparticles showed appreciable negative contrast enhancements in 1.5 tesla T2 MR images, proving their potential as T1 and T2 MRI contrast agents, respectively. This journal is © the Partner Organisations 2014.

Kim H.J.,IBS | Jang H.J.,IBS | Jeon D.,IBS | Hwang J.-G.,KNU | Kim E.S.,KNU
IPAC 2013: Proceedings of the 4th International Particle Accelerator Conference | Year: 2013

Rare Isotope Science Project (RISP) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. The RISP driver linac which is used to accelerate the beam, for an example, Uranium ions from 0.5 MeV/u to 200 MeV/u consists of superconducting RF cavities and warm quadrupole magnets for focusing heavy ion beams. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the requirements of dynamic errors and correction schemes to minimize the beam centroid oscillation and preserve beam losses under control. Copyright © 2013 by JACoW.

Park S.,KNU | Kim E.-S.,KNU | Jang K.-H.,Korea Atomic Energy Research Institute | Park S.H.,Korea Atomic Energy Research Institute | And 2 more authors.
FEL 2013: Proceedings of the 35th International Free-Electron Laser Conference | Year: 2013

Korea Atomic Energy Research Institute (KAERI) has used a microtron accelerator based on a thermionic cathode for operating a compact terahertz (THz) freeelectron laser (FEL). We would like to develop a photocathode- based microtron for generating high-peak (∼ 100 A) and ultrashort (∼ 1 ps) as an electron source for generating intense and ultrashort THz pulses. It is necessary to analyze precisely the electron beam dynamics in a microtron, especially, the relation between the RF phase in a microtron cavity and laser input time for adapting the photocathode to a microtron. Hence, we conduct computer simulation with a 3D PIC-code to find those optimized conditions for the photocathode-based microtron with the beam energy of ∼7 MeV and bunch charge of ∼ 100 pC with a bunch duration of 1 ps. Copyright © 2013 CC-BY-3.0 and by the respective authors.

Park J.Y.,Kyungpook National University | Kim S.J.,Kyungpook National University | Lee G.H.,Kyungpook National University | Jin S.,KNU and Hospital | And 3 more authors.
Journal of the Korean Physical Society | Year: 2015

Surface coating of nanoparticles with ligands is essential in magnetic resonance imaging (MRI) because of solubility in water and biocompatibility. In this study, five organic molecules were used for surface coating of ultrasmall gadolinium-oxide (Gd2O3) nanoparticles (davg = 2.0 nm). All of the samples showed large longitudinal (r1) and transverse (r2) water proton relaxivities with r2/r1 ratios that were close to one, corresponding to ideal conditions for T1 MRI contrast agents. Finally, in-vivo T1 MR images were acquired to prove the effectiveness of the surface-coated ultrasmall Gd2O3 nanoparticles as a T1 MRI contrast agent. © 2015, The Korean Physical Society.

PubMed | KNU and Hospital, Teachers College, Korea Institute of Radiological and Medical Sciences, Kyungpook National University and 2 more.
Type: Journal Article | Journal: Science and technology of advanced materials | Year: 2016

Water-soluble and biocompatible D-glucuronic acid coated Na

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