• Corrosion Science and Technology
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• 제11권4호
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• pp.141-150
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• 2012

Stress corrosion cracks in Alloy 600 compact tension specimens tested at $325^{\circ}C$ in a simulated primary water environment of pressurized water reactor were analyzed by analytical transmission electron microscopy and secondary ion mass spectroscopy (SIMS). From a fine-probe chemical analysis, oxygen was found on the grain boundary just ahead of the crack tip, and chromium oxides were precipitated on the crack tip and the grain boundary attacked by the oxygen diffusion, leaving a Cr/Fe depletion (or Ni enrichment) zone. The oxide layer inside the crack was revealed to consist of a double (inner and outer) layer. Chromium oxides existed in the inner layer, with NiO and (Ni,Cr) spinels in the outer layer. From the nano-SIMS analysis, oxygen was detected at the locations of intergranular chromium carbides ahead of the crack tip, which means that oxygen diffused into the grain boundary and oxidized the surfaces of the chromium carbides. The intergranular chromium carbide blunted the crack tip, thereby suppressing the crack propagation.

• Preventive Nutrition and Food Science
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• 제16권3호
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• pp.224-229
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• 2011

The radical scavenging activity and inhibition effect from lipid peroxidation induced by peroxyl radical of methanol extract from Perilla frutescens and its active compound, rosmarinic acid (RA), were investigated in vitro. The treatment of extract and RA scavenged 1,1-diphenyl-2-picrylhydrazyl, hydroxyl radical (${\cdot}OH$) and nitric oxide in a concentration-dependent manner. In particular, the extract and RA showed strong radical scavenging activity against ${\cdot}OH$, the most toxic and reactive radical. In addition, Perilla frutescens and RA effectively inhibited lipid oxidation induced by sodium nitroprusside and 2,2'-azobis(2-aminopropane) dihydrochloride, determined by the ferric thiocyanate method. The present results suggest that Perilla frutescens and RA play a protective role against oxidative stress induced by free radical and lipid peroxidation.

• 한국통신학회논문지
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• 제15권3호
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• pp.252-259
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• 1990

本 論文은 기존 LOCOS工程의 張點을 모두 겸비한 側面璧 SWAMI 技術에 대한 새로운 構造를 提示한다. 새로운 SWAMI공정은 순수 窒化膜 壓力과 體積 膨腸에 기인한 壓力을 크게 줄이기 위해서 側面璧 주위에 얇은 질화막과 反應性이온 飾刻으로 기울어진 실리콘 측면벽을 結合시켰따. 製作된 結果에 의하면, 缺陷이 없는 완전히 새부리 모양이 形成되지 않는 局地的 酸化 공정은 기울어진 面의 異方性 산화 隔離에 의해 實現시킬 수 있었다. 추가적인 마스크 段階는 要求되지 않는다. 이 工程에서 PN 다이오드의 漏泄電流는 기존 LOCOS 공정 보다 減少되었다. 한편 가장자리 部位는 漏泄電流 密度에서 평편한 接合 부위 보다 높게 分析되었다.

• 한국염색가공학회지
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• 제34권2호
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• pp.127-133
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• 2022

With the increasing interest in the expression of individuality and appearance of modern people, it is time to conduct research and development of novel hair coloring from various angles. Therefore, taking into account the order of discoloration of hair pigments, we selected a creative and novel emulsion as a novel material for hair coloring, rather than a cosmetic material such as hot water extract using natural products dealt with in previous studies, commercially available hair manicure, and oxidation hair dye for hair. Thus, the change in tensile strength and elongation of hair samples by color was studied. As a result of the study, hair with green emulsion paint had a significantly higher maximum load, maximum stress, maximum elongation and breaking load, breaking stress, breaking elongation values are shown. Maximum in terms of modulus, green emulsion applied hair and the control group were higher in the 0-15s strain and 15-145s sections, respectively, and the tangential modulus value was much higher in the control group than the experimental group hairs in all the 0-145s sections. This study, which analyzes the dynamic changes of hair samples that extend the daily color gamut, will greatly contribute to the development of innovative hair coloring materials in the research and production of hair beauty works, and it is judged that it will also contribute to the development of the beauty industry.

• 한국재료학회지
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• 제4권1호
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• pp.63-74
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• 1994

$SiO_{2}$초박막(ultrathin film)의 두께 조절 용이성, 두께 균일성, 공정 재현성 및 전기적 특성을 향상시키기 위해 실리콘을 $N_{2}O$분위기에서 열산화시켰다. $N_2O$분위기에서 박막 성장시 산화와 동시에 질화가 이루어지기 때문에 전기적 특성의 향상을 가져올 수 있었다. 질화 현상에 의해 형성된 Si-N결합 형성은 습식 식각율과 ESCA분석으로 확인할 수 있었다. $N_2O$분위기에서 성장된 $SiO_{2}$박막은 Fowler-Nordheim(FN)전도 기구를 보여주었으며, 절열파괴 특성과 누설 전류특성 및 산화막의 신뢰성은 건식 산화막에 비해서 우수하였다. 또한 계면 포획밀도는 건식 산화막에 비해 감소하였고, 전하를 주입했을 때 생성되는 계면 준위의 양 또는 크게 감소하였다. 산화막 내부에서의 전하 포획의 양도 감소하였고, 전하를 주입하였을 때 생성되는 전하 포획의 양도 감소하였다. 이와 같은 전기적인 특성의 향상은 산화막 내부에서 약하게 결합하고 있는 Si-O 결합들이 Si-N결합으로의 치환과 스트레스 이완에 의하여 감소하였기 때문이다.

• BMB Reports
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• 제50권12호
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• pp.634-639
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• 2017

We aimed to assess the anti-inflammatory and antioxidative properties of KHG26792, a novel azetidine derivative, in amyloid ${\beta}$ ($A{\beta}$)-treated primary microglial cells. KHG26792 attenuated the $A{\beta}-induced$ production of inflammatory mediators such as IL-6, $IL-1{\beta}$, $TNF-{\alpha}$, and nitric oxide. The levels of protein oxidation, lipid peroxidation, ROS, and NADHP oxidase enhanced by $A{\beta}$ were also downregulated by KHG26792 treatment. The effects of KHG26792 against the $A{\beta}-induced$ increases in inflammatory cytokine levels and oxidative stress were achieved by increasing the phosphorylation of $Akt/GSK-3{\beta}$ signaling and by decreasing the $A{\beta}-induced$ translocation of $NF-{\kappa}B$. Our results provide novel insights into the use of KHG26792 as a potential agent against $A{\beta}$ toxicity, including its role in the reduction of inflammation and oxidative stress. Nevertheless, further investigations of cellular signaling are required to clarify the in vivo effects of KHG26792 against $A{\beta}-induced$ toxicity.

• 한국식품위생안전성학회지
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• 제30권4호
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• pp.383-389
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• 2015

본 연구에서는 유도비만 쥐에서 발효 서목태의 항산화 효과를 연구하기 위하여 체중 175 g의 SD계 암컷 흰쥐 24마리를 대상으로 정상 군, 고지방식이 군, 발효 서목태 엑기스 급여 군, 발효 서목태 음료 급여 군으로 분류하여 54일간 사육하였다. in vitro 항산화 활성에서는 발효 서목태 엑기스가 높은 활성 및 함량을 나타냈다. in vivo 항산화 활성에서는 발효 서목태 섭취 군이 고지방식이 대조 군에 비해 CAT, SOD 활성은 높은 활성을 보였으며, MDA량은 감소 현상을 보였다. 이와 같은 결과를 통해 발효 서목태가 항산화 효소의 증가로 활성산소의 제거능을 향상시킬 뿐만 아니라, 생체 내 대사과정에서 생성된 과산화물로부터 생체 조직을 보호하여 손상된 간조직의 기능을 회복시킨 것으로 사료된다.

• The Korean Journal of Physiology and Pharmacology
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• 제21권3호
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• pp.317-325
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• 2017

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease in parallel with worldwide epidemic of obesity. Reactive oxygen species (ROS) contributes to the development and progression of NAFLD. Peroxisomes play an important role in fatty acid oxidation and ROS homeostasis, and catalase is an antioxidant exclusively expressed in peroxisome. The present study examined the role of endogenous catalase in early stage of NAFLD. 8-week-old male catalase knock-out (CKO) and age-matched C57BL/6J wild type (WT) mice were fed either a normal diet (ND: 18% of total calories from fat) or a high fat diet (HFD: 60% of total calories from fat) for 2 weeks. CKO mice gained body weight faster than WT mice at early period of HFD feeding. Plasma triglyceride and ALT, fasting plasma insulin, as well as liver lipid accumulation, inflammation (F4/80 staining), and oxidative stress (8-oxo-dG staining and nitrotyrosine level) were significantly increased in CKO but not in WT mice at 2 weeks of HFD feeding. While phosphorylation of Akt (Ser473) and $PGC1{\alpha}$ mRNA expression were decreased in both CKO and WT mice at HFD feeding, $GSK3{\beta}$ phosphorylation and Cox4-il mRNA expression in the liver were decreased only in CKO-HF mice. Taken together, the present data demonstrated that endogenous catalase exerted beneficial effects in protecting liver injury including lipid accumulation and inflammation through maintaining liver redox balance from the early stage of HFD-induced metabolic stress.

• Clinical and Experimental Reproductive Medicine
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• 제45권2호
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• pp.94-99
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• 2018

Objective: Prompt diagnosis and management are essential for saving the adnexal organs from infarction in cases of ovarian torsion (OT). This study aimed to determine the diagnostic significance of signal peptide, complement C1r/C1s, Uegf, and Bmp1 (CUB), and epidermal growth factor-like domain-containing protein-1 (SCUBE-1) levels in cases of OT, an emergent ischemic condition, and the relationship of SCUBE-1 with oxidative stress parameters. Methods: This prospective study was conducted among 15 OT patients and 20 age- and gravidity-matched healthy women. SCUBE-1 serum concentrations were determined by using enzyme-linked immunosorbent assays. In addition, oxidative stress was evaluated by measuring the serum levels of advanced oxidation protein products (AOPP), ferric reducing ability of plasma (FRAP), and glutathione (GSH). Results: The SCUBE-1 titers were significantly higher in the patients with OT than in the controls (p=0.008). In addition, serum FRAP and GSH levels were significantly lower in the OT patients than in the controls (p<0.001 for both). Serum AOPP levels were higher in the OT patients, but this trend was not statistically significant (p>0.05). Furthermore, there were no correlations between SCUBE-1 levels and age, gravidity, parity, cyst size, and AOPP, FRAP, or GSH levels (p>0.05). Conclusion: We believe that SCUBE-1 may be a promising biomarker for the early diagnosis of OT.

• Nutrition Research and Practice
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• 제8권1호
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• pp.3-10
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• 2014

The rapid increase in the prevalence of metabolic syndrome, which is associated with a state of elevated systemic oxidative stress and inflammation, is expected to cause future increases in the prevalence of diabetes and cardiovascular diseases. Oxidation of polyunsaturated fatty acids and sugars produces reactive carbonyl species, which, due to their electrophilic nature, react with the nucleophilic sites of certain amino acids. This leads to formation of protein adducts such as advanced glycoxidation/lipoxidation end products (AGEs/ALEs), resulting in cellular dysfunction. Therefore, an effective reactive carbonyl species and AGEs/ALEs sequestering agent may be able to prevent such cellular dysfunction. There is accumulating evidence that histidine containing dipeptides such as carnosine (${\beta}$-alanyl-L-histidine) and anserine (${\beta}$-alanyl-methyl-L-histidine) detoxify cytotoxic reactive carbonyls by forming unreactive adducts and are able to reverse glycated protein. In this review, 1) reaction mechanism of oxidative stress and certain chronic diseases, 2) interrelation between oxidative stress and inflammation, 3) effective reactive carbonyl species and AGEs/ALEs sequestering actions of histidine-dipeptides and their metabolism, 4) effects of carnosinase encoding gene on the effectiveness of histidine-dipeptides, and 5) protective effects of histidine-dipeptides against progression of metabolic syndrome are discussed. Overall, this review highlights the potential beneficial effects of histidine-dipeptides against metabolic syndrome. Randomized controlled human studies may provide essential information regarding whether histidine-dipeptides attenuate metabolic syndrome in humans.