Publications by authors named "Chul Soon Lee"

Ammonia (NH) is an irritant gas with a unique pungent odor; sub-parts per million-level breath ammonia is a medical biomarker for kidney disorders and Helicobacter pylori bacteria-induced stomach infections. The humidity varies in both ambient environment and exhaled breath, and thus humidity dependence of gas-sensing characteristics is a great obstacle for real-time applications. Herein, flexible, humidity-independent, and room-temperature ammonia sensors are fabricated by the thermal evaporation of CuBr on a polyimide substrate and subsequent coating of a nanoscale moisture-blocking CeO overlayer by electron-beam evaporation.

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Xylene is a hazardous volatile organic compound, which should be measured precisely for monitoring of indoor air quality. The selective detection of ppm-level xylene using oxide semiconductor chemiresistors, however, remains a challenging issue. In this study, NiO/NiMoO nanocomposite hierarchical spheres assembled from nanosheets were prepared by hydrothermal reaction, and the potential of sensors composed of these nanocomposites to selectively detect xylene gas was investigated.

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Monolayers of periodic porous Co3 O4 inverse opal (IO) thin films for gas-sensor applications were prepared by transferring cobalt-solution-dipped polystyrene (PS) monolayers onto sensor substrates and subsequent removal of the PS template by heat treatment. Monolayer Co3 O4 IO thin films having periodic pores (d≈500 nm) showed a high response of 112.9 to 5 ppm C2 H5 OH at 200 °C with low cross-responses to other interfering gases.

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The use of composite materials and polynary compounds is a promising strategy to promote conductometric sensor performances. The perovskite oxides provide various compositional combinations between different oxides for tuning gas-sensing reaction and endowing rich oxygen deficiencies for preferable gas adsorption. Herein, a sacrificial colloidal template approach is exploited to fabricate crystalline ternary LaFeO3 perovskite porous thin films, by transferring a La(3+)-Fe(3+) hybrid solution-dipped template onto a substrate and sequent heat treatment.

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Phytate is an antinutritional factor that impacts the bioavailability of essential minerals such as Ca(2+), Mg(2+), Mn(2+), Zn(2+), and Fe(2+) by forming insoluble mineral-phytate salts. These insoluble mineral-phytate salts are hydrolyzed rarely by monogastric animals, because they lack the hydrolyzing phytases and thus excrete the majority of them. The β-propeller phytases (BPPs) hydrolyze these insoluble mineral-phytate salts efficiently.

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Lipotoxic cardiomyopathy is caused by myocardial lipid accumulation and often occurs in patients with diabetes and obesity. This study investigated the effects of β-lapachone (β-lap), a natural compound that activates Sirt1 through elevation of the intracellular NAD+ level, on acyl CoA synthase (ACS) transgenic (Tg) mice, which have lipotoxic cardiomyopathy. Oral administration of β-lap to ACS Tg mice significantly attenuated heart failure and inhibited myocardial accumulation of triacylglycerol.

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Family, twin, and adoption studies have demonstrated that genes play an important role in the development of alcoholism. We investigated the association between alcoholism and the genetic polymorphisms of the GABAA receptor genes on chromosome 5q33-34 in Korean population. The genotype of the GABAA receptor gene polymorphisms were determined by performing polymerase chain reaction genotyping for 172 normal controls and 162 male alcoholics who are hospitalized in alcoholism treatment institute.

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