• Journal of Korean Medicine Rehabilitation
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• v.18 no.1
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• pp.95-110
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• 2008

목 적 : 급성 및 만성 염증 질환은 iNOS에 의해서 생성된 과량의 NO와 관련이 있다. 따라서 이러한 질병 치료를 목적으로 NO 생성 억제물질 또는 iNOS 발현 차단물질을 개발할 가치가 있다. 본 연구는 대사 안정성을 개선시킨 dimethoxycurcumin (DiMC)이 활성화된 대식세포에서 NO 생성 및 iNOS 발현을 제어할 수 있는지 조사하였다. 방 법 : RAW264.7 세포를 DiMC (양쪽 방향성 고리에 각각 2개의 methoxy group을 가짐), curcumin (양쪽 방향성 고리에 각각 1개의 methoxy group을 가짐), bis-demethoxycurcumin (양쪽 방향성 고리에 methoxy group이 없음; BDMC) 및 tetrahydrocurcumin (양쪽 방향성 고리에 각각 1개의 methoxy group을 가지고 있지만 중앙 7개 탄소 사슬에 이중결합이 없음; THC)로 각각 전처리한 후에 LPS로 자극하였다. 이들 전처리 물질의 효과를 비교하기 위하여, NO 생성, iNOS 발현, NF-kB p65 인산화 및 p65 DNA-binding 활성을 조사하였다. 결 과 : DiMC, curcumin 및 BDMC는 NO 생성, iNOS 발현 및 NF-kB 활성을 억제하였으며, 그 세기에 있어서 DiMC가 가장 크게 관찰되었고 그 다음 curcumin 그리고 BDMC 순으로 관찰되었다. THC는 어떠한 활성도 보이지 못했다. 결 론 :DiMC는 NO 생성 억제, iNOS 발현 차단 및 NF-kB 비활성을 유도할 수 있음을 알 수 있었다. 이러한 효과는 연속된 이중결합 및 methoxy group의 증가와 관련이 있는 것으로 판단된다.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.2
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• pp.198-206
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• 2008

갯쑥(Artemisia fukudo Makino, 일명 바다쑥)은 바닷가 염전 주변 습지에서 자라는 염생식물로 어린 갯쑥은 나물로 먹어왔으며, 민간에서 간에 좋다고 알려져 있다. 본 연구에서는 염생식물의 기능 성분을 탐색하는 연구의 일환으로 마우스유래 대식세포주인 RAW264.7세포를 이용하여 갯쑥의 nitric oxide(NO) 생성 억제 작용을 알아보고자 하였다. 갯쑥은 methanol 추출과 열수 추출한 후 농축하여 실험하였고, methanol 추출물은 다시 hexane, chloroform, ethylacetate, butanol, water로 순차 용매 분획하여 농축하여, 각각의 추출물을 RAW 264.7 세포에 농도별 분획별로 처리한 후 LPS와 interferon-${\gamma}$로 자극한 RAW 264.7 세 포주의 NO 생성을 측정하여 NO 생성 저해율을 구하였다. 갯쑥 methanol 추출물의 높은 NO 생성 저해율과 iNOS 활성 저해율을 나타내었으며(IR=90.7%과 IR=81.6%), 각각의 추출물중 분획물이 100${\mu}g/mL$ 농도에서 hexane 분획물이 가장 높은 NO 생성 저해 효과(IR=92.1%)와 iNOS 활성 억제 효과(IR=85.0%)를 나타내었다. 갯쑥의 methanol 추출물, hexane과 chloroform 분획물에서 높은 NO 생성 저해 효과를 나타내어 새로운 암 예방인자 물질로 기대되며, 따라서 본 연구 결과는 암 예방인자 분리를 위한 기초 자료가 될 것이며, 나아가 성분 분리 연구와 동물 실험을 통한 기전 연구가 수행되어야 할 것이다.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.192-198
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• 2006

Epidemiological studies have demonstrated an association between exposure to diesel exhaust particles (DEP) and adverse cardiopulmonary effects. Despite the epidemiological proof, the pathogenesis of DEP-related pulmonary diseases remain poorly understood. So, comprehensive in vivo and in vitro researches are required to know the effects of DEP on diverse lung diseases. Alveolar macrophages (AM) and airway epithelial cells are known as important cellular targets in DEP-induced lung diseases. Other studies have shown that nitric oxide (NO) is involved in particle matter induced lung injury. The present study was undertaken to determine whether DEP has an synergistic effects on lipopolysaccharide (LPS)-induced NO formation and inducible nitric oxide synthase (iNOS) with nitrotyrosilated-protein formation in cultured primary alveolar macrophages. The formation of NO was determined through the Griess reaction in the cultured medium and iNOS with nitrotyrosilated-proteins are analyzed by immunohistochemical staining and Western analysis. The results indicate that DEP exposure does not induce NO formation by itself, however DEP showed significant synergistic effects on LPS-induced NO formation. So, our results suggest that DEP inhalation could aggravate inflammatory lung disease through NO formation.

• Food Science and Preservation
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• v.18 no.1
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• pp.65-71
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• 2011

We explored the effect of extracts of dried Platycodon grandiflorum on production of reactive oxygen species (ROS), glutathione (GSH) and nitric oxide (NO). To determine antioxidant activity in the presence of $H_2O_2$-induced oxidative stress, DCFH-DA (dichlorodihydrofluorescin diacetate) assay was employed. Acetone/methylene chloride (A+M) and methanolic (MeOH) extracts of P. grandiflorum reduced intracellular ROS levels. Of the various tested fractions, n-BuOH fraction showed the highest protective effect in terms of lipid peroxide production. Total GSH levels were measured after treatment of HT1080 cells with the A+M and MeOH extracts, and other solvent fractions, at various concentration. The A+M extacts and 85% (v/v) aqueous MeOH fraction significantly increased GSH levels (p<0.05). When lipopolysaccharide (LPS)-induced NO production was evaluated, all tested crude extracts, and fractions thereof, significantly reduced NO production (p<0.05), and the n-BuOH and 85% (v/v) aqueous MeOH fractions (at 0.05 mg/mL) showed the strongest inhibitory effects. The results showed that the n-BuOH fraction inhibited both cellular oxidation and NO production, and this fraction may thus contain valuable active compounds.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.388-389
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• 2003

Nitrous acid는 태양광선의 존재 하에 광분해 되어 히드록실 라디칼(hydroxyl radical, OH)을 발생시키는 대류권 오존생성 원인 물질이다. 대기화학에 있어서 Nitrous acid의 중요성을 보면, 야간에 농도가 증가된 Nitrous acid는 태양광이 존재하는 아침부터 광분해 (<390nm)로 히드록실 라디칼을 생성하여 오존생성반응을 일어나게 하는 것으로 대기 중 오존의 생성에 중요한 역할을 한다. 반면에 Nitric acid는 reactive nitrogen compounds(즉 NO, NO$_2$ 그리고 $N_2$O$_{5}$)의 주된 최종 생성물질이다. (중략)

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.4
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• pp.365-373
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• 2010

A chemical reactor model (CRM) was developed for a jet stirred reactor (JSR) to predict the emission of exhaust such as NOx. In this study, a two-PSR model was chosen as the chemical reactor model for the JSR. The predictions of NO formation in lean premixed methane-air combustion in the JSR were carried out by using CHEMKIN and GRI 3.0 methane-air combustion mechanism which include the four NO formation mechanisms. The calculated results were compared with Rutar's experimental data for the validation of the model. The effects of important parameters on NO formation and the contributions of the four NO pathways were investigated. In the flame region, the major pathway is the prompt mechanism, and in the post flame region, the major pathway is the Zelodovich mechanism. Under the lean premixed condition, the N2O mechanism is the important pathway in both flame and postflame regions.

• The Korean Journal of Mycology
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• v.45 no.4
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• pp.336-344
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• 2017

The anti-inflammatory effects of cell-free extracts from wild yeasts, Meyerozyma guilliermondii YJ34-2 and Rhodotorula graminis YJ36-1, caused by the inhibition of nitric oxide (NO) activity and cytotoxic effects were determined. Cell-free extracts from these two yeast strains had dose-dependent inhibitory effects on the production of lipopolysaccharide-induced NO and there were no cytotoxic effects on the treated cells or negative effects on their proliferation. Their cell-free extracts were also shown to have inhibitory effects on pro-inflammatory cytokines, such as tumor necrosis factor $(TNF)-{\alpha}$ and $prostaglandin-E_2$, in a dose-dependent manner. Maximal inhibitory activity on NO production occurred in cell-free extracts of Meyerozyma guilliermondii YJ34-2 cultivated at $30^{\circ}C$ for 24 hr and Rhodotorula graminis YJ36-1 cultivated at $25^{\circ}C$ for 24 hr in the yeast extract-peptone-dextrose (YPD) media.

• Journal of Power System Engineering
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• v.14 no.6
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• pp.13-19
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• 2010

이 논문에서는 디젤자동차용 LNT와 SCR 촉매의 NO, $NH_3$ 흡착 및 탈리의 기본 특성과 수열화 온도와 시간 및 정량화된 황피독 농도에 대한 de-$NO_x$ 촉매의 내구성을 평가하였다. LNT 촉매는 열적으로 열화됨에 따라 Pt 및 Ba의 소결 및 응집으로 활성이 떨어져 $NO_x$ 전환율은 감소하였다. 반면에 Pt의 비활성화로 중간생성물인 $NH_3$ 생성량은 증가하였으며, 이때 생성된 $NH_3$는 LNT+SCR 복합시스템의 SCR 촉매의 환원제 역할을 담당한다. 1.0 g/L 이상의 황이 피독된 LNT 촉매는 탈황을 하여도 질소 산화물 흡장물질(Ba) 의 성능이 회복이 되지 않아 $NO_x$ 전환율은 회복되지 않았으며, 탈황 후 Pt 재활성화로 인해 NO2 및 SCR 환원제인 $NH_3$ 생성량은 증가하였다. SCR 촉매의 $NO_x$ 전환율은 $700^{\circ}C$ 36h, $800^{\circ}C$ 24h로 수열화 시킨 촉매는 전이금속 입자 성장 및 zeolite 구조 파괴로 인하여 급격하게 떨어졌으며, 0.36 g/L 황 피독된 촉매는 zeolite가 가지는 강산성 특정으로 내피독성이 강하여 탈황시 $NO_x$ 전환율은 회복되었다.

• Clean Technology
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• v.2 no.1
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• pp.96-108
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• 1996

$NO_x$ is mainly emitted from mixed acid pickling process in the stainless industry and its impact to the environment has been worried over. This study which may be considered as one of the development of clean technologies, differing from the traditional end pipe technology is about how to reduce $NO_x$ emission through the modification of corresponding process. This study consists of two parts. First, the influence of various reaction parameters in a acid pickling process on $NO_x$ emission was investigated. Second, the influence of hydrogen peroxide on $NO_x$ formation, which is known as inhibitor of $NO_x$ emission, was investigated. Major findings in this study are as follows. The important reaction parameters which have a great influence on $NO_x$ emission are the reaction temperature and the concentration of fluoric acid. The concentration of nitric acid, some of which results in $NO_x$ compound is not as important as the concentration of fluoric acid. Synthetic mixed acid of nitric acid and fluoric acid itself in absent of pickling plate contributed the $NO_x$ emission, however, its impact was negligible in terms of quantity. The addition of hydrogen peroxide to the acid pickling process significantly contributed to the reduction of $NO_x$ emission and successfully achieved 80% reduction of $NO_x$ emission at the condition of $9.51{\times}10^{-2}mole\;hydrogen\;peroxide/m^2$ pickling area. This result was compared to literature value from Avesta steel process, indicating a sixth of hydrogen peroxide addition of Avesta's in achieving a same amount of $NO_x$ reduction. The region of the economic hydrogen peroxide addition per unit area of plate to be pickled from the result of this study was established.

• Journal of Life Science
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• v.33 no.1
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• pp.50-55
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• 2023

This study was designed to determine the activities of Rosa davurica Pall. leaf extract and their regulatory mechanisms in macrophage inflammation. Anti-inflammatory potential of Rosa davurica Pall. leaf extract was evaluated by measuring the nitric oxide (NO) release and inducible nitric oxide synthase (iNOS) synthesis in lipopolysaccharide (LPS)-treated macrophage Raw 264.7 cells. Rosa davurica Pall. leaf extract potently inhibited LPS-induced NO release in a dose dependent manner. However, cell viability decreased to about 50% at high dose of 500 ㎍/ml, resulting in cytotoxicity. LPS-induced iNOS protein expression was also reduced significantly after treatment with Rosa davurica Pall. leaf extract. Furthermore, extract of Rosa davurica Pall. attenuated LPS-mediated phosphorylation of IκB and nuclear factor (NF-κB). Suppression of NF-κB signaling by treatment with PDTC, an NF-κB specific inhibitor, accelerated the inhibition of NO production and iNOS protein expression. These results suggest that Rosa davurica Pall. exhibits the anti-inflammatory potential in LPS-induced macrophage inflammation, partly through inhibition of NO production by down-regulation of NF-κB signaling.