• 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.

• BMB Reports
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• 제29권3호
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• pp.200-204
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• 1996

Nerve growth factor (NGF) is literally known to promote neural differentiation and survival in several peripheral and central neurons. Thus, it is Widely believed that NGF may serve as a therapeutic agent for many types of neuronal diseases. One of the mechanisms suggested to explain the protective role of NGF is that the trophic factor can prevent the increase of intracellular calcium ions which might be responsible for neural death. To examine whether or not the calcium hypothesis works even under pathological conditions, we applied NGF to cultures deprived of glucose. Surprisingly, what was observed here is that NGF rather promoted cell death under a glucose-deprived condition. What we call the NGF paradox phenomenon occurred in a calcium concentration-dependent manner, indirectly suggesting that NGF might increase intracellular calcium ions in cells deprived of glucose. This suggestion is further supported by the fact that nifedipine, a well-known L-type calcium channel blocker, could block the cell death potentiated by NGF. Here it is still premature to propose the complete mechanism underlying the NGF paradox phenomenon. However, this study certainly indicates that NGF as a therapeutic agent for neuronal diseases should be carefully considered before use.

• 미생물학회지
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• 제42권3호
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• pp.195-198
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• 2006

Anthrax lethal toxin은 탄저병의 치사원인이 되는 독소이며, Lethal toxin은 두 종류의 단백질 PA (Protective antigen)과 LF (lethal factor)로 구성되어 진다. PA는 세포표면의 수용체와 결합하여 LF를 세포질 안으로 이동시켜 주는 역할을 한다. LF는 금속 이온$(Zn^{2+})$ 의존적 단백질 가수분해 효소로써 MKKs[MAPK (mitogen-activated protein kinase) kinases] 집단 단백질의 아미노 말단 부분을 절단하여 대상 세포를 죽음으로 유도하는 것으로 알려져 있다. 본 연구에서는 LF에 대한 특성 분석 및 억제제 개발에 과한 연구를 위해 cell-based high-throughtput screens 개발에 선행되어야 하는 기초 자료를 마련하는데 그 목적이 있다. 이를 위하여 LF의 절단 대상이 되는 기질이 MEK1을 yeast내에서 동시 발현시켜 LF의 활성을 검증하였다. 먼저 효모(Saccharomyces cerevisiae)를 숙주로 하여 LF의 기질인 MEK1 발현 vector를 구축하였고, 구축된 발현 system을 기본을 LF 활성을 검증하고자 yeast에 형질전환하여 plasmid의 안전성 및 MEK1 유전자의 발현 및 LF에 의한 MEK1 아미노말단의 절단 부위를 확인하였다. 본 연구는 세포내 검증 system 도입의 기초적 자료를 제공하였으며, yeast내의 MEK1 발현은 탄저병의 저해제 선별 및 활성 측정 검증을 생체에서 고효율적이며, 안정적으로 할 수 있다는 가능성을 나타냈다.

• International Journal of Advanced Culture Technology
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• 제6권2호
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• pp.30-35
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• 2018

In contemporary society, neglected families increase adolescents' maladjustment behaviors, causing academic problems, psychological and emotional problems, and showing flight behavior. By identifying the nature of the protective factor against the dangerous environment of a neglected family and increasing the protection factor for the children in a dangerous environment, it is necessary to create the environment so that the young can grow up positively rather than adversely. The purpose of this study is to identify the characteristics of adolescents who are psychologically adaptive at the level of general family children among the adolescents who are in a dangerous environment. The results showed that self - esteem, ego - resilience, ego - identity, and community variables had a significant effect on discriminating adolescents who showed high psychological adjustment from risk factors of neglect while controlling other factors. SPSS 20.0 was used to analyze the data.

• Toxicological Research
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• 제29권3호
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• pp.165-172
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• 2013

Acetaminophen (APAP) known as paracetamol is the main ingredient in Tylenol, which has analgesic and anti-pyretic properties. Inappropriate use of APAP causes major morbidity and mortality secondary to hepatic failure. Overdose of APAP depletes the hepatic glutathione (GSH) rapidly, and the metabolic intermediate leads to hepatocellular death. This article reviews the mechanisms of hepatotoxicity and provides an overview of current research studies. Pharmacokinetics including metabolism (activation and detoxification), subsequent transport (efflux)-facilitating excretion, and some other aspects related to toxicity are discussed. Nuclear factor erythroid 2-related factor 2 (Nrf2)-regulated gene battery plays a critical role in the multiple steps associated with the mitigation of APAP toxicity. The role of Nrf2 as a protective target is described, and potential natural products inhibiting APAP toxicity are outlined. This review provides an update on the mechanism of APAP toxicity and highlights the beneficial role of Nrf2 and specific natural products in hepatoprotection.

• Journal of Korean Biological Nursing Science
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• 제14권2호
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• pp.129-138
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• 2012

Purpose: Cachexia is a complex metabolic syndrome associated with wasting of skeletal muscle which contributes to nearly one-third of all cancer deaths. Cachexia lowers the frequency of response to chemotherapy and radiation and ultimately can impact survival as well as quality of life during treatment. NF-kappa B is one of the most important molecular mediators of cachexia. In this study, therefore, possible candidates for inhibitors of NF-kappa B were searched. Methods: Amino acids that regulate cellular redox potential by adjusting the level of NAD/NADH ratio, such as aspartate, pyruvate, and isocitrate were selected. Results: Pyruvate effectively inhibited luciferase activity in TNF-stimulated 293T cells transfect with an NF-kB dependent luciferase reporter vector. Pyruvate also showed protective effect on muscle atrophy of differentiated C2C12 myocyte induced by TNF/IFN. Conclusion: We might be able to develop the nutritional management strategy for cancer cachexia patients with pyruvate supplementation.

• 아동학회지
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• 제29권3호
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• pp.127-156
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• 2008

This study aimed to verify the mediating effects of cognitive function and social support and to establish a structural relationship between child maltreatment and resilience in school-age children (n=357) taken in by child protection service. In the first model (linear arrangement), each protective factor mediates independently between maltreatment and resilience; in the second model (arrangement in due order), cognitive function has mediating effects prior to social support. Analysis of data included descriptive statistics, Cronbach's a, confirmatory factor analysis, and structural equation modeling. Results of the first model showed indirect effects of cognitive function and social support. Results of the second model significantly affirmed that the mediators, cognitive function and social support, diminish negative effects of maltreatment by bolstering resilience.

• 아동학회지
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• 제35권5호
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• pp.1-14
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• 2014

This study explored the determinants of smartphone addiction among mothers of infants, focusing on their socio-demographic characteristics, parental stress, and parental knowledge. A total 220 mothers of infants were surveyed and the collected data were analyzed by binary logistic regression. A considerable percentage (16%) of mothers of infants were observed to be at a risk of smartphone addiction, which was significantly higher than the percentage (8%) of adult population at risk of smartphone addiction reported by the Korean government. Parental stress from dysfunctional parent-child relationships was a risk factor and parental knowledge about infant development was observed to be a protective factor when it came to the smartphone addiction of mothers' with infants. However, socio-demographic characteristics (number of children, age, education, family income, and job) did not have statistically significant associations with their smartphone addiction.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.44-45
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• 2008

The zone 3 elements of distance relays play an important role during the propagation of cascaded events. The most challenging problem to mitigate catastrophic failures is to distinguish between actual faults with line flow transfer from other disconnected lines. This paper presents an adaptive protective relaying scheme based on Line Outage Distribution Factor(LODF) and Generation Shift Factor(GSF) to prevent zone 3 tripping during the cascaded events. Internet based secure peer to peer communication is recommended as a communication method of proposed scheme. Several communication issues such as reliability, speed and cyber security are discussed. In order to establish the feasibility of the proposed scheme, computer simulations for a six bus system has been performed.