Korea University

About: Korea University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Population & Thin film. The organization has 39756 authors who have published 82424 publications receiving 1860927 citations. The organization is also known as: Bosung College & Bosung Professional College.

Defect-free nanoporous thin films from ABC triblock copolymers.

Abstract: The self-assembly of triblock copolymers of poly(ethylene oxide-b-methyl methacrylate-b-styrene) (PEO-b-PMMA-b-PS), where PS is the major component and PMMA and PEO are minor components, provides a robust route to highly ordered, nanoporous arrays with cylindrical pores of 10-15 nm that show promise in block copolymer lithography These ABC triblock copolymers were synthesized by controlled living radical polymerization, and after solvent annealing, thin films showing defect-free cylindrical microdomains were obtained The key to the successful generation of highly regular, porous thin films is the use of PMMA as a photodegradable mid-block which leads to nanoporous structures with an unprecedented degree of lateral order The power of using a triblock copolymer when compared to a traditional diblock copolymer is evidenced by the ability to exploit and combine the advantages of two separate diblock copolymer systems, the high degree of lateral ordering inherent in PS-b-PEO diblocks plus the facile degradability of PS-b-PMMA diblock copolymer systems, while negating the corresponding disadvantages, poor degradability in PS-b-PEO systems and no long-range order for PS-b-PMMA diblocks

Genome-wide association study identifies FCGR2A as a susceptibility locus for Kawasaki disease.

Abstract: Kawasaki disease is a systemic vasculitis of unknown etiology, with clinical observations suggesting a substantial genetic contribution to disease susceptibility. We conducted a genome-wide association study and replication analysis in 2,173 individuals with Kawasaki disease and 9,383 controls from five independent sample collections. Two loci exceeded the formal threshold for genome-wide significance. The first locus is a functional polymorphism in the IgG receptor gene FCGR2A (encoding an H131R substitution) (rs1801274; P = 7.35 × 10(-11), odds ratio (OR) = 1.32), with the A allele (coding for histadine) conferring elevated disease risk. The second locus is at 19q13, (P = 2.51 × 10(-9), OR = 1.42 for the rs2233152 SNP near MIA and RAB4B; P = 1.68 × 10(-12), OR = 1.52 for rs28493229 in ITPKC), which confirms previous findings(1). The involvement of the FCGR2A locus may have implications for understanding immune activation in Kawasaki disease pathogenesis and the mechanism of response to intravenous immunoglobulin, the only proven therapy for this disease.

Flexible supercapacitor electrodes based on real metal-like cellulose papers.

Abstract: The effective implantation of conductive and charge storage materials into flexible frames has been strongly demanded for the development of flexible supercapacitors. Here, we introduce metallic cellulose paper-based supercapacitor electrodes with excellent energy storage performance by minimizing the contact resistance between neighboring metal and/or metal oxide nanoparticles using an assembly approach, called ligand-mediated layer-by-layer assembly. This approach can convert the insulating paper to the highly porous metallic paper with large surface areas that can function as current collectors and nanoparticle reservoirs for supercapacitor electrodes. Moreover, we demonstrate that the alternating structure design of the metal and pseudocapacitive nanoparticles on the metallic papers can remarkably increase the areal capacitance and rate capability with a notable decrease in the internal resistance. The maximum power and energy density of the metallic paper-based supercapacitors are estimated to be 15.1 mW cm−2 and 267.3 μWh cm−2, respectively, substantially outperforming the performance of conventional paper or textile-type supercapacitors. With ligand-mediated layer-by-layer assembly between metal nanoparticles and small organic molecules, the authors prepare metallic paper electrodes for supercapacitors with high power and energy densities. This approach could be extended to various electrodes for portable/wearable electronics.

Photocurrent in ZnO nanowires grown from Au electrodes

Abstract: ZnO nanowires were grown between two Au electrodes on an Al2O3-deposited Si wafer. Photoresponse, photoresponse spectrum, and current–voltage (I–V) studies were performed for the investigation into photoconduction mechanism in these nanowires. The photoresponse of the nanowires under the continuous illumination of light with above- or below-gap energies was slow, which indicates that photocurrent in the nanowires is surface-related rather than bulk-related. The photoresponse spectrum represents the above- and below-gap absorption bands for the photocurrents. The I–V characteristics under the illumination of the above-gap light are ohmic, but the characteristics under the illumination of the below-gap light are Schottky. This observation indicates that the above-gap light lowers the potential barrier built in the contact between the ZnO nanowires and electrodes, but that the below-gap light does not lower the potential barrier.