• Journal of Sensor Science and Technology
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• v.17 no.1
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• pp.61-68
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• 2008

The sensing characteristics of new oxide sensing materials, NiO, NiO-YSZ and CuO, were evaluated at the temperature of $700^{\circ}C$ in 10 % $O_2$containing atmosphere. Through simultaneous response to $NO_2$ and NO, the sensing mechanism of oxide electrode was studied and the relation of EMF and NO/$NO_2$ concentrations was elucidated. Moreover, for highly sensitive NOx sensor, modified mixed potential sensor which has at least two oxide electrodes was proposed.

• Biomolecules & Therapeutics
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• v.2 no.2
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• pp.131-135
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• 1994

The effect of ginsenoside (GS) from Panax ginseng on basal and nitro-L-arginine suppressed nitric oxide (NO) production was studied in rat kidney. NO production was determined by conversion to [$^{14C}$]=L-citrulline from [$^{14C}$]-L-arginine both in whole kidney and three renal segments; glomerulus, cortex excluding glomerulus (cortex-) and medulla. Nitro-L-arginine (total dose of 30 mg/kg/3 days, i.p.) significantly reduced NO production in whole kidney, which was prevented by GS pretreatment (30 mg/kg/3 days, i.p.). Relative high dose of GS (120 mg/kg/4 days, i.p..) selectively increased NO production in glomerulus and cortex-. Protein content, on wet weight basis, in cortex- and glomerular DNA content were significantly reduced by GS. Our results confirm the existence of constitutive nitric oxide synthase in kidney and it seems that target nephron segment for volume expansion due to GS'NO-mediated vasodilation and for NO production stimulated by GS is cortex including glomerulus.lus.

• Korean Journal of Materials Research
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• v.25 no.4
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• pp.171-176
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• 2015

We present the detection characteristics of nitrogen monoxide(NO) gas using p-type copper oxide(CuO) thin film gas sensors. The CuO thin films were fabricated on glass substrates by a sol-gel spin coating method using copper acetate hydrate and diethanolamine as precursors. Structural characterizations revealed that we prepared the pure CuO thin films having a monoclinic crystalline structure without any obvious formation of secondary phase. It was found from the NO gas sensing measurements that the p-type CuO thin film gas sensors exhibited a maximum sensitivity to NO gas in dry air at an operating temperature as low as $100^{\circ}C$. Additionally, these CuO thin film gas sensors were found to show reversible and reliable electrical response to NO gas in a range of operating temperatures from $60^{\circ}C$ to $200^{\circ}C$. It is supposed from these results that the p-type oxide semiconductor CuO thin film could have significant potential for use in future gas sensors and other oxide electronics applications using oxide p-n heterojunction structures.

• Biomedical Science Letters
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• v.25 no.2
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• pp.196-200
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• 2019

Effect of retinoids, i.e., all-trans retinoic acid and 13-cis retinoic acid, on the activity of nitric oxide synthase (NOS) was evaluated in human malignant keratinocytes to examine the possible correlation of retinoids with NOS activities. All-trans retinoic acid and 13-cis retinoic acid did not alter the nitric oxide (NO) production. However, in the presence of lipopolysaccharide (LPS, $1{\mu}g/mL$), they significantly increased NO release in a dose-dependent manner until 48 h at concentrations of $50{\sim}100{\mu}M$. The degree of upregulation of NO by all-trans retinoic acid and 13-cis retinoic acid increased up to 35% and 37%, respectively, compared to that by the control, which demonstrated the upregulation of LPS-inducible nitric oxide synthase (iNOS)-dependent generation of NO as well as showing a crucial link between retinoids-induced activity and NOS. Findings of this study now suggest that the upregulation of LPS-iNOS activity may be associated with modulation of retinoids-induced control of cellular developmental processes, which may produce new therapeutics of retinoids in the complexity of how NO affects human keratinocytes.

• Korean Journal of Materials Research
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• v.28 no.1
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• pp.32-37
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• 2018

We report on the efficient detection of NO gas by an all-oxide semiconductor p-n heterojunction diode structure comprised of n-type zinc oxide (ZnO) nanorods embedded in p-type copper oxide (CuO) thin film. The CuO thin film/ZnO nanorod heterostructure was fabricated by directly sputtering CuO thin film onto a vertically aligned ZnO nanorod array synthesized via a hydrothemal method. The transport behavior and NO gas sensing properties of the fabricated CuO thin film/ZnO nanorod heterostructure were charcterized and revealed that the oxide semiconductor heterojunction exhibited a definite rectifying diode-like behavior at various temperatures ranging from room temperature to $250^{\circ}C$. The NO gas sensing experiment indicated that the CuO thin film/ZnO nanorod heterostructure had a good sensing performance for the efficient detection of NO gas in the range of 2-14 ppm under the conditions of an applied bias of 2 V and a comparatively low operating temperature of $150^{\circ}C$. The NO gas sensing process in the CuO/ZnO p-n heterostructure is discussed in terms of the electronic band structure.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.295-296
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• 2015

We presented the methods calculating the reduction efficiency of nitrogen oxide for the low $NO_x$ burner as the pollution prevention facilities. The standard $NO_x$ concentration was used on the emission factor of LNG, $3.7g/m^3$. The $NO_x$ reduction efficiency based on the $NO_x$ concentration was presented and the relationships between the $NO_x$ concentration and the emission factor or the specific heat emission factor were derived. These results could be accurately reflected on calculating the amount of the nitrogen oxide emissions. In addition, according to the arrangement of the low $NO_x$ burners the methods of applying their $NO_x$ reduction efficiency were proposed. The $NO_x$ reduction efficiency for the facilities consisting of the low $NO_x$ burners and the non-low $NO_x$ burners could be estimated with information about the reduction efficiency of each low $NO_x$ burners, the fuel consumption rate, and the heating value of fuel.

• Korean Journal of Materials Research
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• v.26 no.2
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• pp.84-89
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• 2016

We present the rectifying and nitrogen monoxide (NO) gas sensing properties of an oxide semiconductor heterostructure composed of n-type zinc oxide (ZnO) and p-type copper oxide thin layers. A CuO thin layer was first formed on an indium-tin-oxide-coated glass substrate by sol-gel spin coating method using copper acetate monohydrate and diethanolamine as precursors; then, to form a p-n oxide heterostructure, a ZnO thin layer was spin-coated on the CuO layer using copper zinc dihydrate and diethanolamine. The crystalline structures and microstructures of the heterojunction materials were examined using X-ray diffraction and scanning electron microscopy. The observed current-voltage characteristics of the p-n oxide heterostructure showed a non-linear diode-like rectifying behavior at various temperatures ranging from room temperature to $200^{\circ}C$. When the spin-coated ZnO/CuO heterojunction was exposed to the acceptor gas NO in dry air, a significant increase in the forward diode current of the p-n junction was observed. It was found that the NO gas response of the ZnO/CuO heterostructure exhibited a maximum value at an operating temperature as low as $100^{\circ}C$ and increased gradually with increasing of the NO gas concentration up to 30 ppm. The experimental results indicate that the spin-coated ZnO/CuO heterojunction structure has significant potential applications for gas sensors and other oxide electronics.

• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.600-605
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• 2022

In this study, nitrogen oxide (NO_x) removal experiments were performed using a graphene based ceramic filter coated with a V₂O₅-WO₃-TiO₂ catalyst. Graphene oxide (GO) was prepared by Hummer's method using graphite, and the reduced graphene oxide was produced by reducing with hydrazine (N₂H₄). Vanadium (V), Tungsten (W), and Titanium (Ti) were coated by the sol-gel method, and then a metal oxide-supported filter was prepared through a calcination process at 350 ℃. A NO_x removal efficiency test was performed for the catalytic ceramic filters with UV light in a humid condition. When graphene oxide (GO) and reduced graphene oxide (rGO) were present on the filter, the NOx removal efficiency was superior to that of the conventional ceramic filter. Most likely, this is due to an improvement in the adsorption properties of NOx molecules on graphene coated surfaces. As the concentration of graphene increased, higher NO_x removal efficiency was confirmed.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.691-700
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• 2008

One suggested mechanism underlying copper (Cu) deficiency teratogenicity is a low availability of nitric oxide (NO), signaling molecule which is essential in developmental processes. Increased superoxide anions secondary to decreased activities of Cu-zinc superoxide dismutase (Cu-Zn SOD) in Cu deficiency can interact with NO to form peroxynitrite, which can nitrate proteins at tyrosine residues. In addition, peroxynitrite formation can limit NO bioavailability. We previously reported low NO availability and increased protein nitration in Cu deficient (Cu-) embryos. In the current study, we tested whether Cu deficiency alters downstream signaling of NO by assessing cyclic GMP (cGMP) and phosphorylated vasodilator-stimulating phosphoprotein (VASP) levels, and whether NO supplementation can affect these targets as well as protein nitration. Gestation day 8.5 embryos from Cu adequate (Cu+) or Cu- dams were collected and cultured in either Cu+ or Cu- media for 48 hr. A subset of embryos was cultured in Cu- media supplemented with a NO donor (DETA/NONOate; 20 ${\mu}M$) and/or Cu-Zn SOD. Cu-/Cu- embryos showed a higher incidence of embryonic and yolk sac abnormalities, low NO availability, blunted dose-response in NO concentrations to increasing doses of acetylcholine, low mRNA expression of endothelial nitric oxide synthase (eNOS), increased levels of 3-nitrotyrosine (3-NT) compared to Cu+/Cu+ controls. cGMP concentrations tended to be low in Cu-/Cu- embryos, and they were significantly lower in Cu-/Cu- yolk sacs than in controls. Levels of phosphorylated VASP at serine 239 (P-VASP) were similar in all groups. NO donor supplementation to the Cu- media ameliorated embryonic and yolk sac abnormalities, and resulted in increased levels of cGMP without altering levels of P-VASP and 3-NT. Taken together, these data support the concept that Cu deficiency limits NO availability and alters NO/cGMP-dependent signaling in Cu- embryos and yolk sacs, which contributes to Cu deficiency-induced abnormal development.

• Korean Journal of Acupuncture
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• v.24 no.1
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• pp.189-197
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• 2007

Objectives : Free radical metabolism seems to occupy a remarkably common position in the mechanisms of aging and aging related disease. This study was designed to find out whether Juglandis Semen herbal acupuncture solution (JSHAS) can scavenge Nitric Oxide (NO) or not. Methods : SNAP was used as NO generator. NO concentration was estimated after 2, 6, 12 and 24 hrs in no treatment group, after treatment with Vitamin C or 1, 10, 100 ${\mu}g/ml$ of JSHAS. Results : There was no significant scavenging effect of JSHAS on NO after 2, 6 hrs but significant effect on NO in 10, 100 ${\mu}g/ml$ group. Conclusions : These results suggest that JSHAS has scavenging effect on NO. This study shows that JSHAS can be used for aging related disease and further studies are required to investigate the antioxidative effects of it.