• 치위생과학회지
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• 제19권3호
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• pp.198-204
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• 2019

Background: Oxidative stress is a known to be associated with in the pathogenesis of many inflammatory diseases, including periodontitis. Ursolic acid is a pentacyclic triterpenoid with has antimicrobial, antioxidative, and anticancer properties. However, the role of ursolic acid in the regulating of osteogenesis remains undetermined. This study was aimed to elucidate the crucial osteogenic effects of ursolic acid and its ability to inhibit oxidative stress by targeting the immediate early response 3 (IER3)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Methods: Cell proliferation was determined using water-soluble tetrazolium salt assay, cell differentiation was evaluated by alkaline phosphatase (ALP) activity, and formation of calcium nodules was detected using alizarin red S stain. Generation of reactive oxygen species (ROS) was determined using by DCFH-DA fluorescence dye in hydrogen peroxide ($H_2O_2$)-treated MG-63 cells. Expression levels of IER3, Nrf2, and heme oxygenase-1 (HO-1) were analyzed using western blot analysis. Results: Our results showed that ursolic acid up-regulated the proliferation of osteoblasts without any cytotoxic effects, and promoted ALP activity and mineralization. $H_2O_2$-induced ROS generation was found to be significantly inhibited on treatment with ursolic acid. Furthermore, in $H_2O_2$-treated cells, the expression of the early response genes: IER3, Nrf2, and Nrf2-related phase II enzyme (HO-1) was enhanced in the presence of ursolic acid. Conclusion: The key findings of the present study elucidate the protective effects of ursolic acid against oxidative stress conditions in osteoblasts via the IER3/Nrf2 pathway. Thus, ursolic acid may be developed as a preventative and therapeutic agent for mineral homeostasis and inflammatory diseases caused due to oxidative injury.

• Journal of Photoscience
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• 제9권2호
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• pp.323-325
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• 2002

Bacillus Anthracis is the causative agent of anthrax. The major virulence factors are a poly-D glutamic acid capsule and three-protein component exotoxin, which is collectively known as anthrax toxin, protective antigen (PA, 83 kDa), lethal factor (LF, 90 kDa), and edema factor (EF, 89 kDa). These three proteins individually have no known toxic activities, but in combination with PA form two toxins (lethal toxin and edema toxin), causing different pathogenic responses in animals and cultured cells. However, it remains to be elucidated for pathogenic mechanism of anthrax toxin. In this study, we constructed toxin component in bacterial overexpression system and purified the native toxin from Bacillus anthracis delta sterne F32 using FPLC system. Recombinant toxin showed high homogeneity and rapid purification processes. Also, this recombinant toxin was comparable to B. anthracis native toxin in terms of cytotoxic effects on cultured cell lines.

• 한국군사과학기술학회지
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• 제14권4호
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• pp.710-718
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• 2011

Edema factor(EF) is a portion of anthrax toxin which produces edema when combined with protective antigen. This paper describes about technique for cloning, expression, purification and activity test of EF. Using the E. coli expression system, we could make recombinant EF protein although it's origin is Bacillus anthracis. And also we could culture massively and purify highly pure protein. Finally we confirm a enzyme activity of purified EF to increase intracellular cAMP level. Through establishing this technique, it can be possible to research about EF in depth and apply to expression and purification of many other protein in biology.

• 대한한방내과학회지
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• 제33권3호
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• pp.272-283
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• 2012

Objectives : The purpose of this study was to investigate the mechanism of protective effect of Jinmu-tang (JMT, Zhenwu-tang) extract on $H_2O_2$-induced cell death in C6 glial cells. Methods : Cultured C6 glial cells of white mice were pretreated with JMT extract and exposed to $H_2O_2$ for inducing cell death. We measure the cell viability by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and investigate the cell morphology using a light microscope after crystal violet (CV) staining. Reactive oxygen species (ROS) formation was analyzed using a flow cytometer and a fluorescent microscope after staining with 2'7'-dichlorofluorescein diacetate (DCF-DA). DNA fragmentation was analyzed using a flow cytometer after propidium iodide (PI) staining and nuclei morphology was investigated using a fluorescent microscope after 2-[4-amidinophenyl]-6-indo-lecarbamidine dihydrochloride (DAPI) staining. We analyzed expression of Bax, processing of procaspase-3 and poly (ADP-ribose) polymerase (PARP), and activation of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) by western blot method. Tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) secretion was analyzed using Quantikine kit. Results : We determined the elevated cell viability by JMT extract on $H_2O_2$-induced C6 glial cell death. ROS formation, DNA fragmentation, $I{\kappa}B{\alpha}$ phosphorylation, NF-${\kappa}B$ activation, and secretion of TNF-${\alpha}$ induced by $H_2O_2$ are inhibited by JMT extract pre-treatment. JMT extract inhibits Bax expression, processing of caspase-3 and PARP that are critical biochemical markers of apoptotic cell death. Conclusions : These results suggest that JMT extract has a protective effect on $H_2O_2$-induced C6 glial cell death in various pathways.

• 사회복지연구
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• 제39호
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• pp.315-342
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• 2008

본 연구는 청소년패널조사의 1-4차년도 종단자료를 이용하여 비행행동의 발달궤적을 확인하고자 하였다. 다층모형분석(HLM)에 기반한 성장곡선모형을 이용하여 비행행동의 수준과 변화율을 추정하였다. 중학교 2학년에서 측정한 보호 및 위험요인이 최종 측정시점에서의 비행행동 수준과 변화율에 어떠한 영향을 미치고 있는지 확인해 보았다. 연구모형에서 상정한 보호 및 위험요인은 부모의 양육행동, 자기통제력, 비행친구와의 교류, 부정적 낙인 등이었다. 성별과 가구의 사회경제적 배경변인이 통제변인으로 포함되었다. 분석결과, 성별과 부모의 학력, 가구소득은 비행행동의 수준과 변화율에 유의미한 영향을 미치는 것으로 나타났다. 빈곤가족이면서 남자청소년일 경우, 청소년 후기에 비행행동을 경험할 가능성은 높았고, 그 증가세도 가파른 것으로 나타났다. 아울러 부모와의 애착관계를 제외한 모든 보호(위험) 요인이 비행행동의 수준에 유의미한 영향을 미치는 것으로 나타났다. 보호(위험) 요인들은 이론들이 예측하는 방향과 일치하는 결과로 비행행동에 대해 억제 또는 강화하는 효과를 가지는 것으로 나타났다. 비행행동의 변화율과 관련하여 유의미한 영향을 미치는 것으로 확인된 보호 및 위험요인은 자기통제력과 비행친구와의 교류로 나타났다. 비행친구와의 교류가 적었던 청소년들의 비행행동 증가율은 더 높은 것으로 나타났고, 자기통제력이 높은 청소년의 경우 시간이 지남에 따라 비행행동의 증가율은 상대적으로 완만하게 나타났다. 보호 및 위험요인이 비행행동의 궤적에 미치는 영향을 종단자료를 통해 분석한 결과에 기반하여 청소년의 비행행동 예방 및 개입을 위한 실천적 함의를 살펴보았고, 필요한 후속연구의 과제에 대해 제시하였다.

• 대한본초학회지
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• 제36권1호
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• pp.59-66
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• 2021

Objectives : Forsythiae Fructus has been reported to have anti-inflammatory effects in many diseases, and Corydalis Tuber has been used as a pain suppressor in Eastern Asia. However, the protective effects of individual water extract of Forsythiae Fructus (FF) and Corydalis Tuber (CT) and the mixture of FF and CT (FC) on chronic pancreatitis (CP) were not well-investigated. Therefore, we investigated the protective effects of FF, CT, and FC on CP in mice. Methods : To induce CP, cerulein was injected 6 times a day, 4 times a week for 3 weeks. 1 h before the every cerulein injection, 200 mg/kg of FF, CT, or FC was intraperitoneally injected to mice. Histological analysis of pancreas was examined by hematoxylin and eosin stain and collagen deposition was examined by Masson's trichrome stain. Fibrogenic parameters such as α-smooth muscle actin (α-SMA), extracellular matrix (ECM) deposition, and fibrotic cytokines such as transforming growth factor (TGF)-β1 and platelet-derived growth factor (PDGF) were also analyzed by immunofluorescence stain and real-time PCR. Results : Histological damages in pancreas were inhibited by pre-treatment of FF or FC but not CT. α-SMA and ECM in pancreas were inhibited by pre-treatment of CT or FC but not FF. Moreover, the expression of TGF-β1 and PDGF in pancreas were inhibited by FF, CT or FC. Conclusions : Our results suggest that FC have protective effect on CP in mice through inhibition of α-SMA, ECM, TGF-β1 and PDGF in pancreas, and these findings could suggest new clinical strategy for CP.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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• pp.290-293
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• 2001

This paper presents the reach accuracy of a distance relay for protection of transmission line according to power system conditions. The apparent impedance of distance relay is considerably affected by source impedance, load current, power factor, fault point and resistance etc. For protective coordination on the variables power system parameters, trip characteristics of distance relay at sending and receiving terminal are discussed.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 춘계학술대회 논문집
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• pp.66-67
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• 2003

It is well known that osteoblasts and osteoc1asts playa key role in bone metabolism. They involve in osteoformation or bone destruction which are ragulated by various factors such as thyroid hormone, parathyroid hormone, estrogen, growth factor and cytokine. Recently, it is demonstrated that oxidative stress is one of pathological factors in bone metabolism, but it is left unknown about mechanism between oxidative stress and bone metabolism.(omitted)

• 한국분말재료학회지
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• 제11권3호
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• pp.217-223
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• 2004

Submicron nickel powders were prepared from aqueous solution under hydrothermal condition. The experimental conditions including the types of protective agents, concentration of the solution and the pH were studied in detail. Starting concentration of nickel ion is a dominant factor affecting particle size. It was shown that the subsequent addition of Poly Vinyl Pyrrolidone(PVP) and Sodium Dodecyle Sulfate(SDS) can help to disperse the nickel powder. X-ray diffraction and SEM were employed to characterize the products.

• 한국심리학회지 : 문화 및 사회문제
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• 제12권5호_spc
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• pp.99-116
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• 2006

본 연구의 주된 목적은 청소년의 다양한 위험행동을 예방하기 위한 보호요인의 역할을 탐색하는데 있다. 청소년은 발달적 특성상 위험행동 가능성이 매우 높지만, 그것이 문제행동으로 연결되는 데는 위험요인의 부정적인 영향력을 상쇄시켜주는 보호요인이 이들에게 작용하지 않는 것이 가장 커다란 원인이라고 추정된다. 본 연구에서는 이와 같은 가정을 검증하기 위하여 이미 문제행동(비행)에 개입한 특수집단 청소년(소년원, 보호관찰소) 216명과 위험행동 가능성이 높은 일반 실업계 고등학교 청소년 1,020명을 대상으로 선행연구들에서 확인된 보호요인의 영향력을 검증해 보고자 하였다. 예컨대, 특정 위험행동(가출, 흡연 등)에 대해 보호요인이 작용할 경우 그것이 문제행동으로 발전할 가능성은 낮지만, 그렇지 않을 경우 문제행동의 확률은 의미있게 높을 것이다. 측정도구는 위험행동(가출, 흡연, 성관계) 개입 여부를 확인하기 위한 3개의 선다형 문항과 위험행동 경향성을 알아보기 위한 위험행동 지각척도(21개 문항의 5점 평정척도), 그리고 5개 변인의 보호요인(긍정적 가족기능, 부모 모 각각에 대한 의사소통, 사회적 지지, 자기효능감)척도이다. 연구의 결과 특수집단은 일반집단보다 가출과 흡연, 성관계 각각에 대한 경험이 의미있게 더 많을 뿐만 아니라 보호요인이 이들 각 위험행동을 설명해 주지 못하였다. 반면에 일반 청소년 집단에는 보호요인이 가출과 비가출, 흡연과 비흡연, 성관계 유무를 각각 의미있게 판별해 주었다. 따라서 보호요인은 일반 청소년들에게 있어 그들의 위험행동이 문제행동으로 발전하는 경로를 차단해 주고 있음을 나타낸다. 본 연구의 결과는 보호요인이 청소년들의 적응유연성 (resilience을 향상시킴으로서 문제행동 개입 가능성을 감소시킬 수 있다는 선행연구들에 근거하여 논의되었다.