• Journal of Environmental Science International
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• v.32 no.7
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• pp.503-520
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• 2023

In this study, numerical simulations using community multiscale air quality (CMAQ) were conducted to analyze the change in ozone (O₃) concentration due to the reduction in nitrogen oxides (NO_x)andvolatile organic compounds (VOCs) emissions in Busan. When the NO_x and, VOCs emissions were reduced by 40% and, 31%, respectively, the average O₃ concentration increased by 4.24 ppb, with the highest O₃ change observed in the central region (4.59 ppb). This was attributed to the decrease in O₃ titration by nitric oxide (NO) due to the reduction of NO_x emissions in Busan, which is classified as a VOCs-limited area. The distribution of O₃ concentration changes was closely related to NO_x emissions per area, and inland emissions were highly correlated with daily maximum concentrations and 8-h average O₃ concentrations. Contrastingly, the effect of emission reduction depended on the wind direction. This suggests that the emission reduction effects may vary depending on the environmental conditions. Further research is needed to comprehensively analyze the emission reduction effects in Busan.

• The Korea Journal of Herbology
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• v.27 no.3
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• pp.83-88
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• 2012

Objects : This study was performed in order to observe the effects of water extract of Dendrobii herba on intracerebral hemorrhage(ICH), Method : ICH was induced by the stereotaxic intrastriatal injection of bacterial collagenase type IV in Sprague-Dawley rats. After the water extracts of Dendrobii herba were administrated orally once a day for 3 days, hematoma volume, percentage of brain edema, expression of iNOS and MPO were observed using immunohistochemistry. Results : Rats fed with water extracts of Dendrobii herba showed reduction of hematoma volume and percentage of brain edema compared with controls. In addition, Infiltration of myeloperoxidase (MPO) expressing neutrophil and expression of inducible nitric oxide synthatase(iNOS) were significantly reduced in rats fed with water extracts of Dendrobii herba. Conclusion : These results demonstrated that water extracts of Dendrobii herba reduced brain damage of intracerebral hemorrhage(ICH) and subsequent ICH-induced cerebral edema, and inhibited neutrophil infiltration.

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.349-356
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• 2002

The present study was performed to examine the effect of fangchinoline, a bis- benzylisoquinoline alkaloid, which exhibits the characteristics of a $Ca^{2+}$ channel blocker, on cyanide-induced neurotoxicity using cultured rat cerebellar granule neurons. NaCN produced a concentration-dependent reduction of cell viability, which was blocked by MK-801, an N-methyl-D-aspartate (NMDA) receptor antagonist, verapamil, L-type$Ca^{2+}$channel blocker, and L-NAME, a nitric oxide synthase inhibitor. Pretreatment with fangchinoline over a concentration range of 0.1 to 10 $\mu$M significantly decreased the NaCN-induced neuronal cell death, glutamate release into medium, and elevation of $[Ca^{2+}]_i$ and oxidants generation. These results suggest that fangchinoline may mitigate the harmful effects of cyanide-induced neuronal cell death by interfering with $[Ca^{2+}]_i$influx, due to its function as a $Ca^{2+}$ channel blocker, and then by inhibiting glutamate release and oxidants generation.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.356-360
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• 2005

Xanthine dehydrogenase (XDH), a classic enzyme involved in purine catabolism, can catalyze the formation of redox-signaling reactive oxygen and nitrogen species such as superoxide and nitric oxide. We generated transgenic plants of Arabidopsis in which XDH was knocked out by introduction of hairpin RNA-expression vector. Expression analysis by reverse transcription-PCR and in-gel staining of XDH activity revealed that transgenic lines efficiently suppressedXDH expression at the transcriptional level, demonstrating that RNA interference was successfully induced. XDH-suppressed transgenic lines exhibitedincreased biomass production during the growth of seedlings.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.355-357
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• 2014

The usefulness of unsteady combustion was experimentally investigated using confined premixed flames stabilized by a rearward-facing step. For this purpose, apparatus of forced pulsating mixture supply, which could be modulated its amplitude and frequency, was designed. The unsteady combustion used in this experiment plays an important role in controlling self-excited combustion oscillations and furthermore it exhibits desirable performance, from a practical point of view, such as high load combustion and reduction of pollutant emission like nitric oxide.

• Journal of the Korean Society of Combustion
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• v.10 no.4
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• pp.1-9
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• 2005

The usefulness of unsteady combustion was experimentally investigated using confined premixed flames stabilized by a rearward-facing step. For this purpose, apparatus of forced pulsating mixture supply, which could be modulated its amplitude and frequency, was designed. The unsteady combustion used in this experiment plays an important role in controlling self-excited combustion oscillations and furthermore it exhibits desirable performance, from a practical point of view, such as high load combustion and reduction of pollutant emission like nitric oxide.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.3
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• pp.216-223
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• 2008

Reburning is a useful technology in reducing nitric oxide through injection of a secondary hydrocarbon fuel. In this paper, an experimental study has been conducted to evaluate the effect of fuel lean reburning on $NO_X/CO$ reduction in LPG flame. Experiments were performed in flames stabilized by a co-flow swirl burner, which was mounted at the bottom of the furnace. Tests were conducted using LPG gas as the reburn fuel as well as the main fuel. The effects of reburn fuel fraction and injection location of the reburn fuel were studied when the fuel lean reburning system was applied. The paper reports data on flue gas emissions and temperature distribution in the furnace for a wide range of experimental conditions. At steady state, temperature distribution and emission formation in the furnace have been measured and compared. This paper makes clear that in order to decrease both NOx and CO concentrations in the exhaust when the fuel lean reburning system was adapted, it is important that the control of some factors such as initial equivalence ratio, reburn fuel fraction and temperature of reburn fuel injection region. Also it shows the fuel lean reburning is also effective method to reduce NOx as much as reburning.

• The Journal of Internal Korean Medicine
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• v.24 no.2
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• pp.203-212
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• 2003

Objective : As a link in chain of research to confirm the oriental medical prescription which has the anti-atherosclerosis effects, this research evaluated the effects on the macrophage-related factors by using KanghwalSokdantang(KS). Methods : In order to perform this research, we have evaluated the effects on the oxLDL formation from the macrophages, the nitric oxide formation, and the oxidation of macrophages. Thus, with this evaluation, we have investigated the applicapability on the artherosclerosis. Results : KanghwalSokdantang has showed a noticeable reduction of protein oxidation in the process of oxLDL formation, has remarkably restrained phospholipid peroxidation, an index to estimated the phospholipid oxidation and reduction that are formed in the process of macrophage's oxLDL formation, and has increased the nitrite concentration noticeably in the LDL-dealing macrophages. By increasing the survival rate of macrophages, KanghwalSokdantang has restrained the cellular damages. KanghwalSokdantang is ineffective on the LDH outflow from damaged cells. $1{\mu}g/ml$ KanghwalSokdantang sample has increased acid phosphatase activity remarkably. Conclusion : KanghwalSokdantang has the possibility to be used in the prevention and treatment of atherosclerosis, which is formed by the oxLDL formation of macrophages.

• Korean Journal of Materials Research
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• v.34 no.5
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• pp.254-260
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• 2024

This study is to manufacture a titanium dioxide (TiO₂) photocatalyst by recycling sludge generated using titanium tetrachloride (TiCl₄) as a coagulant. Compared to general sewage, a TiCl₄ coagulant was applied to dyeing wastewater containing a large amount of non-degradable organic compounds to evaluate its performance. Then the generated sludge was dried and fired to prepare a photocatalyst (TFS). Scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), and nitrogen oxide reduction experiments were conducted to analyze the surface properties and evaluate the photoactive ability of the prepared TFS. After using titanium tetrachloride (TiCl₄) as a coagulant in the dyeing wastewater, the water quality characteristics were measured at 84 mg/L of chemical oxygen demand (COD), 10 mg/L of T-N, and 0.9 mg/L of T-P to satisfy the discharge water quality standards. The surface properties of the TFS were investigated and the anatase crystal structure was observed. It was confirmed that the ratio of Ti and O, the main components of TiO₂, accounted for more than 90 %. As a result of the nitric oxide (NO) reduction experiment, 1.56 uMol of NO was reduced to confirm a removal rate of 20.60 %. This is judged to be a photocatalytic performance similar to that of the existing P-25. Therefore, by applying TiCl₄ to the dyeing wastewater, it is possible to solve the problems of the existing coagulant and to reduce the amount of carbon dioxide generated, using an eco-friendly sludge treatment method. In addition, it is believed that environmental and economic advantages can be obtained by manufacturing TiO₂ at an eco-friendly and lower cost than before.

• Biomolecules & Therapeutics
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• v.9 no.3
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• pp.167-175
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• 2001

Recent studies have shown that cytokines are capable of modulating cardiovascular function and that some drugs used in the treatment of heart failure variably modulate the production of cytokines. Hige- namine, a positive inotropic isoquinoline alkaloid, has been used traditionally as cardiac stimulant, and reported to reduce nitric oxide (NO) and inducible nitric oxide synthase (iNOS) expression in LPS- and/or cytokine-activated cells in vitro and in vivo. Therefore, we investigated whether higenamine modulates the production of proinflammatory cytokines in myocardial infarction. In addition, effects of higenamine on antioxidant action and antioxidant enzyme expression (MnSOD) were studied. Myocardial infarction (MI) was confirmed by measuring left ventricular (LV) pressure after occlusion of the left anterior descending coronary artery (LAD) for 5 weeks in rats. Treatment of higenamine (10 mg/kg/day) reduced infarct size about 35 %, which accompanied by reduction of production TNF-$\alpha$, IL-6, but not IFN-${\gamma}$ and IL-1$\beta$ in the myocardium. The expression of TNF-$\alpha$ mRNA in infracted myocardium was significantly reduced by higenamine. Although iNOS mRNA was not detected, nitrotyrosine staining was significantly increased in myocardium of Ml compared to higenamine-treated one, Indicating that peroxynitrite-induced damage is evident in MI. Cytochrome c oxidation by peroxynitrite was concentration-dependently reduced by higenamine, an effect which was almost compatible to glutathion. Higenamine treatment did not affect the expression of MnSOD mRNA in myocardial tissues in MI. Taken together, higenamine may be beneficial in oxidative stress conditions such as ischemic-reperfusion injury and MI due to antioxidant action as well as modulation of cytokines.