• 제목/요약/키워드: Transient Response Analysis

검색결과 563건 처리시간 0.022초

Transduced Human Copper Chaperone for Cu,Zn-SOD (PEP-1-CCS) Protects Against Neuronal Cell Death

  • Choi, Soo Hyun;Kim, Dae Won;Kim, So Young;An, Jae Jin;Lee, Sun Hwa;Choi, Hee Soon;Sohn, Eun Jung;Hwang, Seok-Il;Won, Moo Ho;Kang, Tae-Cheon;Kwon, Hyung Joo;Kang, Jung Hoon;Cho, Sung-Woo;Park, Jinseu;Eum, Won Sik;Choi, Soo Young
    • Molecules and Cells
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    • 제20권3호
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    • pp.401-408
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    • 2005
  • Reactive oxygen species (ROS) contribute to the development of various human diseases. Cu,Zn-superoxide dismutase (SOD) is one of the major means by which cells counteract the deleterious effects of ROS. SOD activity is dependent upon bound copper ions supplied by its partner metallochaperone protein, copper chaperone for SOD (CCS). In the present study, we investigated the protective effects of PEP-1-CCS against neuronal cell death and ischemic insults. When PEP-1-CCS was added to the culture medium of neuronal cells, it rapidly entered the cells and protected them against paraquat-induced cell death. Moreover, transduced PEP-1-CCS markedly increased endogenous SOD activity in the cells. Immunohistochemical analysis revealed that it prevented neuronal cell death in the hippocampus in response to transient forebrain ischemia. These results suggest that CCS is essential to activate SOD, and that transduction of PEP-1-CCS provides a potential strategy for therapeutic delivery in various human diseases including stroke related to SOD or ROS.

복합재의 파괴와 hygrothermal 효과에 관한 연구 (Fracture and Hygrothermal Effects in Composite Materials)

  • Kook-Chan Ahn;Nam-Kyung Kim
    • 한국안전학회지
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    • 제11권4호
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    • pp.143-150
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    • 1996
  • 본 연구는 선형, 비선형 hygrothermal 응력 문제를 위한 explicit-Implicit 유한요소 해석 모델 개발에 관한 것이다. 부가적으로 moilsture 확산 방정식, J-적분 평가를 위한 균열 요소 및 가상 균열 진전법이 도입된다. 시간 변화에 따른 균열 추진력을 계산하기 위하여 선형 탄성 파괴 역학(LEFM)이론이 고려되며 재료의 기공은 실온에서 액체 상태의 습기로 포화되어 있으며 온도가 상승함에 따라 증기화된다는 가정하에서 균열 추진력과 증기 효과의 관계가 연구된다. 이상 기체방정식은 각 시간 단계에서 증기에 의한 열역학적 압력을 계산하기 위하여 이용된다. 다공질 재료의 시간 종속 응답을 지배하는 방정식들은 혼합이론에 기초하며 다공질 재료의 유체 흐름을 위한 Darcy의 법칙과 Von-Mises 항복 기준을 포함하고 있는 Perzyna의 점소성 모델이 첨가된다. 또한 Green-Naghdi 응력률이 중첩된 강체 운동하에서 응력 텐서 invariant로 사용되며, 모델링을 위하여 사각요소가 이용되고 비선형 지배 방정식을 풀기 위하여 full Newton-Raphson법에 의한 반복법이 사용된다. 본 연구를 통하여 얻은 결과는 다음과 같다. 1) 본 유한요소 프로그램은 복합재의 hygrothermal 파괴 해석에 매우 유용하게 적용될 수 있다. 2) 습기의 온도에 의한 영향을 가지는 재료의 J-적분을 정확히 예측하기 위하여는 증기 효과를 고려하여야 한다. 왜냐하면 초기단계에 균열 전파력이 가속되기 때문이다. 3) 본 해석을 위해 Uncoupled scheme에 의한 결과도 Coupled scheme에 결과에 비해 아주 타당하므로 CPU 측면에서 매우 경제적인 Uncoupled scheme이 추천된다.

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Prediction of itching diagnostic marker through RNA sequencing of contact hypersensitivity and skin scratching stimulation mice models

  • Kim, Young-Won;Zhou, Tong;Ko, Eun-A;Kim, Seongtae;Lee, Donghee;Seo, Yelim;Kwon, Nahee;Choi, Taeyeon;Lim, Heejung;Cho, Sungvin;Bae, Gwanhui;Hwang, Yuseong;Kim, Dojin;Park, Hyewon;Lee, Minjae;Jang, Eunkyung;Choi, Jeongyoon;Bae, Hyemi;Lim, Inja;Bang, Hyoweon;Ko, Jae-Hong
    • The Korean Journal of Physiology and Pharmacology
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    • 제23권2호
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    • pp.151-159
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    • 2019
  • Pruritus (itching) is classically defined as an unpleasant cutaneous sensation that leads to scratching behavior. Although the scientific criteria of classification for pruritic diseases are not clear, it can be divided as acute or chronic by duration of symptoms. In this study, we investigated whether skin injury caused by chemical (contact hypersensitivity, CHS) or physical (skin-scratching stimulation, SSS) stimuli causes initial pruritus and analyzed gene expression profiles systemically to determine how changes in skin gene expression in the affected area are related to itching. In both CHS and SSS, we ranked the Gene Ontology Biological Process terms that are generally associated with changes. The factors associated with upregulation were keratinization, inflammatory response and neutrophil chemotaxis. The Kyoto Encyclopedia of Genes and Genomes pathway shows the difference of immune system, cell growth and death, signaling molecules and interactions, and signal transduction pathways. Il1a, Il1b and Il22 were upregulated in the CHS, and Tnf, Tnfrsf1b, Il1b, Il1r1 and Il6 were upregulated in the SSS. Trpc1 channel genes were observed in representative itching-related candidate genes. By comparing and analyzing RNA-sequencing data obtained from the skin tissue of each animal model in these characteristic stages, it is possible to find useful diagnostic markers for the treatment of itching, to diagnose itching causes and to apply customized treatment.