• 제목/요약/키워드: barrier function

검색결과 593건 처리시간 0.022초

아토피 피부염 치료제 개발에 활용할 수 있는 마우스 모델에 대한 고찰 (Mouse Models of Atopic Dermatitis for Drug Discovery from Medicinal Plants)

  • 윤용갑;황주민;김형률;장선일
    • 대한한의학방제학회지
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    • 제15권1호
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    • pp.145-161
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    • 2007
  • Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with cutaneous hyperreactivity to environmental triggers. The clinical phenotype that characterizes AD is the product of interactions between susceptible genes, the environmental factors, defective skin barrier function, and immunologic responses. This review summarizes recent progress in our understanding of the immunopathophysiology of AD and the implications for mouse models of AD in drug discovery from medicinal plants.

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Strategy to Overcome Drug Resistance That Develops during Treatment of Chronic Hepatitis B in Children

  • Hong, Suk Jin;Choe, Byung-Ho
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제15권2호
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    • pp.63-73
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    • 2012
  • Development of antiviral resistance to lamivudine is the most important factor for the treatment failure. It is necessary to establish proper guidelines to overcome drug resistance for children with chronic hepatitis B. Primary treatment with lamivudine should be considered if patients are in immune-clearance phase and have persistently elevated ALT levels more than twice the upper limit of normal value. Before initiating the therapy, careful consideration of the patient's status is required to exclude abnormal liver function tests due to other causes. The treatment option should be carefully decided to suppress the viral replication effectively. To obtain good compliance, clinicians should educate patients and their parents. Appropriate monitoring for virologic breakthrough and genotypic resistance is important in deciding to change the treatment plan. Sequential monotherapy should be avoided and a combination of drugs in other categories is recommended. New antiviral agents, such as entecavir and tenofovir, which have high potency and high genetic barrier, are soon expected to be available for use with children.

반도체 접촉장벽 특성의 컴퓨터해석(II (Computer Analysis of Semiconductor Barrier Characteristics (II))

  • Jong-Woo Park;Keum-Chan Whang;Chang-Yub Park
    • 대한전기학회논문지
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    • 제32권7호
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    • pp.234-238
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    • 1983
  • 이 논문은 단일 전하로 전달되는 이중(금속-반도체-금속) 접착 소자에서 일차원적인 수송 방정식을 정상 상태에서 마이크로 컴퓨터로 해를 구하였다. 수송방정식을 해석적으로 풀이 하기 위해 일반적으로 행하여왔던 대부분의 가정과 개략치는 본 논문에서는 배제하였다. 결과는 에너지 상태, 밀도상태, 전류-전압 특성등에 관하여 중점을 두엇다. 인가 전압의 함수로 나타낸 미분 정전 용얄의 컴퓨터에 의한 해를 제시히고 영상전하 효과로 수정법도 제시 하였다.

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Enterobacter cloacae MG82에 의한Triphenylmethane흡수 특성과 탈색효소의 세포내 위치

  • 정민선;곽순전;김병홍;정영건;강사욱;민경희
    • 한국미생물·생명공학회지
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    • 제25권1호
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    • pp.37-43
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    • 1997
  • Triphenylmethane was decolorized rapidly by enterbacter cloacae MG 82 at initial reaction time. The spheroplast showed higher activity of triphenylmentane decolorization than that of intact cell suspension. The outer part of the bacterial cell envelope and the peptidoglycan are important for the function of transport barrier of triphenylmethane. In intact cell, decolorization activity was higher at 37$\circ $C than at $\circ $C, indicating that triphenylmethane decolorization is due to the enzyme reaction. Culture filtrate showed no decolorization activity, while cell-free extract appeared high activity of 1.45 units, clearly showing that decolorization activity was due to the cell-free extract. Comparing decolorization activities of cell fractions, it was found that decolorization activity was located at the compartment of cytoplasmic membrane. The enzyme activity was also shown to be Mg$^{++}$-dependent. The optimum pH and temperature of enzyme activity were 7.0 and 50$\circ $C, respectively. The thermostability of this enzyme at 35$\circ $C was kept to 58% for 3 hours.

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Experimental Investigations on Barrier Oxidation in $N_{B}/A_{L}O_{X}/N_{B}$ Josephson Junctions

  • Kim, Kyu-Tae;Hong, Hyun-Kwon;Lee, Sang-Hwa;Nam, Du-Woo;Lee, Kyu-Won
    • 한국초전도ㆍ저온공학회논문지
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    • 제5권1호
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    • pp.17-20
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    • 2003
  • Josephson junctions were fabricated for several oxidation conditions and several junction sizes. Considering self-field effect suppressing the observed critical current (Ic) at large junctions, the observed Ic values were in good agreement with theoretical prediction. The predicted junction critical current for small junction limit was also confirmed by experiment. The dependence of the estimated Jc as a function of oxidation exposure showed that our junctions have lower Jc than other authors' at the same oxidation exposure. This is thought to be one of equipment-specific phenomena. Details of experimentals will be reported with brief discussion.

비피더스 연구동향 (Research Trends in Bifidobacterium)

  • 박명수;지근억
    • KSBB Journal
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    • 제25권4호
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    • pp.319-329
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    • 2010
  • Bifidobacteria comprises up to 25% of the cultivable fecal bacteria in adults and 80% in infants. Many in vivo and clinical research results supporting its efficacy in the prevention and improvement of gastrointestinal health have been accumulated. As a consequence, expert committee WHO/FAO expert committee recommended Bifidobacterium as representative probiotics together with Lactobacillus acidophilus. In this review, research trends in bifidobacteria concerning the classification and identification of the genus Bifidobacterium, modulation of intestinal microflora, improvement of constipation, prevention of diarrhea, alleviation of atopy and allergy, barrier function through antimicrobial activity andimmune enhancement of the host will be introduced. Several gene expression systems based on bifidobacterial plasmids have been developed and successfully used to express several heterologous genes including anticancer proteins in Bifidogacterium. In animal test, bifidobacteria was proven to be a promising candidate for safe gene delivery system which can specifically colonize in the solid tumor.

Sb2O3 첨가제가 ZnO 배리스터의 전기적 특성에 미치는 영향 (The Effect of Sb2O3 Additive on the Electrical Properties of ZnO Varistor)

  • 김용혁
    • 전기학회논문지
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    • 제65권10호
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    • pp.1697-1701
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    • 2016
  • The leakage conduction and critical voltage characteristic of ZnO ceramic were investigated as a function of $Sb_2O_3$ concentration. Leakage conduction in the ohmic region increased with increasing $Sb_2O_3$ concentration and was attributed to the potential barrier height. The nonlinear coefficient increased with an increasing amount of $Sb_2O_3$. It was found that increases in the apparent critical voltages were associated with the lowered donor concentration in the grain boundary of between two ZnO grains. And the decrease of donor concentration on doping with $Sb_2O_3$ additive was attributed to the lowered capacitance in the grain boundary layer.

AN ADAPTIVE PRIMAL-DUAL FULL-NEWTON STEP INFEASIBLE INTERIOR-POINT ALGORITHM FOR LINEAR OPTIMIZATION

  • Asadi, Soodabeh;Mansouri, Hossein;Zangiabadi, Maryam
    • 대한수학회보
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    • 제53권6호
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    • pp.1831-1844
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    • 2016
  • In this paper, we improve the full-Newton step infeasible interior-point algorithm proposed by Mansouri et al. [6]. The algorithm takes only one full-Newton step in a major iteration. To perform this step, the algorithm adopts the largest logical value for the barrier update parameter ${\theta}$. This value is adapted with the value of proximity function ${\delta}$ related to (x, y, s) in current iteration of the algorithm. We derive a suitable interval to change the parameter ${\theta}$ from iteration to iteration. This leads to more flexibilities in the algorithm, compared to the situation that ${\theta}$ takes a default fixed value.

A Diffusion Model for a System Subject to Random Shocks

  • Lee, Eui-Yong;Song, Mun-Sup;Park, Byung-Gu
    • Journal of the Korean Statistical Society
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    • 제24권1호
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    • pp.141-147
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    • 1995
  • A diffusion model for a system subject to random shocks is introduced. It is assumed that the state of system is modeled by a Brownian motion with negative drift and an absorbing barrier at the origin. It is also assumed that the shocks coming to the system according to a Poisson process decrease the state of the system by a random amount. It is further assumed that a repairman arrives according to another Poisson process and repairs or replaces the system i the system, when he arrives, is in state zero. A forward differential equation is obtained for the distribution function of X(t), the state of the systme at time t, some boundary conditions are discussed, and several interesting characteristics are derived, such as the first passage time to state zero, F(0,t), the probability of the system being in state zero at time t, and F(0), the limit of F(0,t) as t tends to infinity.

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일체화된 Aperture 구조의 한계전류형 산소센서의 제작 및 특성 (Fabrication and characteristics of limit-current type oxygen sensor with monolith aperture structure)

  • 오영제;이득용
    • 센서학회지
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    • 제17권4호
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    • pp.273-280
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    • 2008
  • Monolith aperture-type oxygen sensors with simple structure of YSZ(pin-hole)/Pt/ YSZ(solid electrolyte)/Pt were fabricated by co-firing technique. To enhance the yield of productivity, a couple of YSZ green sheets for diffused barrier and solid electrolyte were prepared by tape-casting and co-firing method. The limit current characteristics of the oxygen sensors were measured between 500 and $650^{\circ}C$ The heating temperature of $600^{\circ}C$ was optimum as a portable oxygen sensor in the range of oxygen concentration from 0 to 75 vol%. Linear proficiency of limit current behavior as a function of oxygen concentration was controlled by the variation of aperture dimension. The fabricated oxygen sensors showed the stable sensing output for 30 days. Gas leakage in bonding area due to warping, cracking and thermal cycling was not found in the period.