• 제목/요약/키워드: blocking effects

검색결과 648건 처리시간 0.032초

Effects of Chronic Lead Exposure on Glutamate Release and Uptake in Cerebellar Cells of Rat Pups

  • Yi, Eun-Young;Lim, Dong-Koo
    • Archives of Pharmacal Research
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    • 제21권2호
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    • pp.113-119
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    • 1998
  • Changes in the release and uptake of glutamate in cerebellar granule and glial cells of offspring of lead-exposed mothers were determined. In cultured cerebellar granule cells exposed to lead for 5 days, glutamate release was less influenced upon N-methyl-D-aspartate (NMDA) stimulation than that in the control. Although the NMDA-stimulated release of glutamate in cerebellar granule cells prepared from lead-exposed first generation pups was not different from that of the control group, the S-nitroso-N-acetylpenicillamine (SNAP)-stimulated release of glutamate in cerebellar granule cells obtained from lead-treated pups was less elevated than that in the control. Furthermore, in cerebellar granule cells obtained from lead-exposed second generations pups, glutamate release did not respond to both NMDA and SNAP stimulation. In cerebellar glial cells exposed to lead, the basal glutamate uptake was not changed. However, the L-trans-pyrollidine-2,4-dicarboxylic acid (PDC)-blocking effects was significantly reduced. In glial cells obtained from lead-exposed pups, the glutamate uptake was also less blocked by PDC than that in the control. Further decreases in PDC-blocking effects were observed in cerebellar glial cells obtained from lead-treated second generation pups compared to those from the control group. These results indicate that lead exposure induces the changes in the sensitivities of the glutamate release and uptake transporter. In addition, these results suggest that lead exposure might affect the intracellular signalling pathway and transmission in glutamatergic nervous system.

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An Optimization of the Porous Asphalt Pavement Permeability Function Focusing on the Surface Free Energy of Polymer Fog-Coat Methods

  • Ohmichi Massaru;Yamanokuchi Hiroshi;Maruyama Teruhiko
    • 한국도로학회논문집
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    • 제8권2호
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    • pp.13-22
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    • 2006
  • Surface fog coating methods to porous pavements with a polymer, that contains MMA as a main ingredient, are being widely used in Japan and called 'Top-Coat Processes'. They have lots of effects such as to prevention of the pavement void choking, improvement of the water permeability of the pavements and so on. The purpose of this research is to show the characterization of the polymer to optimize the functions of the polymer fog-coat methods. This study focused on the difference of 'wetting' by water among polymers used for the fog coatings, and calculation the surface free energy from the water contact angle on each material. At the end, the water permeability test were conducted using porous asphalt mixtures that were coated with several kinds of polymers. The permeability was also measured on the specimens that were forcibly choked by muddy water and the resistance to choking was compared. It is concluded that the reduction of the surface free energy between water and a polymer improves the life of the permeability functions of porous pavements. Improvement of water permeation capacity and void-blocking controlling effects can be quantitatively evaluated using the interfacial tension ($\gamma$sl) with water for the coating material (high-viscosity asphalt and hardening resin binder). Consequently, the smaller the $\gamma$sl of the coating material the higher the water permeation capacity and void-blocking controlling effects of the porous asphalt pavements.

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Anti-inflammatory Activity of Fucoidan with Blocking NF-κB and STAT1 in Human Keratinocytes Cells

  • Ryu, Min Ju;Chung, Ha Sook
    • Natural Product Sciences
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    • 제21권3호
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    • pp.205-209
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    • 2015
  • Fucoidan, a sulfated polysaccharide is found in several types of edible brown algae. It has shown numerous biological activities; however, the molecular mechanisms on the activity against atopic dermatitis have not been reported yet. We now examined the effects of fucoidan on chemokine production co-induced by TNF-α/IFN-γ, and the possible mechanisms underlying these biological effects. Our data showed that fucoidan inhibited the TNF-α/IFN-γ-induced production of thymus and activation-regulated chemokine (TARC) and macrophagederived chemokine (MDC) mRNA in human keratinocytes HaCaT cells. Also, fucoidan suppressed phosphorylation of nuclear factor kappa B (NF-κB) and activation of signal transducer and activator of transcription (STAT)1 in a dose-dependent manner. In addition, fucoidan significantly inhibited activation of extracellular-signal-regulated kinases (ERK) phosphorylation. These data indicate that fucoidan shows anti-inflammatory effects by suppressing the expression of TNF-α/IFN-γ-induced chemokines by blocking NF-κB, STAT1, and ERK1/2 activation, suggestive of as used as a therapeutic application in inflammatory skin diseases, such as atopic dermatitis.

Differential Vasorelaxant Effects of KR-30075, a New Cyclic AMP-phosphodiesterase Inhibitor, on Guinea-pig Pulmonary, Bovine Coronary and Renal Arteries

  • Jung, Yee-Suk;Kwon, Kwang-Il;Zee, Ok-Pyo
    • Archives of Pharmacal Research
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    • 제13권2호
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    • pp.136-141
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    • 1990
  • The vasorelaxant effects of KR-30075 in guinea-pig pulmonary, bovine coronary and renal arterial strips contracted by either$K^+$depolarization, phenylephrine, or prostaglandin $F_{2a}$($PGF_{2a}$) were evaluated. KR-30075 was more potent than imazodan as a vasorelaxant against $PGF_{2a}$-induced contractions in bovine coronary and renal arteries, whereas against$K^+$induced contractions KR-30075 was less potent than imazodan in guieapig pulmonary arteries and more potent in bovine coronary arteries. KR-30075 was more potent against contractions induced by phenylephrine or $PGF_{2a}$ than the contractions induced by $K^+$ This profile of activity for KR-30075 was similar to that of imazodan and dissimilar from the calcium entry blocking agent nifedipine. There was no vascular selectivity of KR-30075 between bovine coronary and renal arterial strip preparations. In conclusion, this study shows that KR-30075 represents the vasorelaxant effects on guinea-pig pulmonary, bovine coronary and renal arteries without specific vascular selectivity. The vasorelaxant profile of KR-30075, with different sources of vascular smooth muscle, is unlike that of calcium entry blocking agent and more similar to the profile of the agent that inhibit cyclic nucleotide phosphodiesterase.

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삼황세제(三黃洗劑)가 Raw 264.7 cell 에서의 항염 효과에 미치는 영향 (The Effects of Samhwangseje on Anti-Inflammation in Raw 264.7 cell)

  • 정순영;서형식
    • 한방안이비인후피부과학회지
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    • 제22권1호
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    • pp.108-119
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    • 2009
  • Objectives : This study was carried out to investigate the effects of Samhwangseje(SHSJ) on anti-Inflammation in Raw 264.7 cell. Methods : The effects of SHSJ on anti-Inflammation were measured by the cytotoxicity of Raw 264.7 cell, the inhibition for NO, TNF-$\alpha$, $PGE_{2}$, iNOS and COX-2, the blocking NF-${\kappa}B$ into nucleus. Results : 1. All concentrations of SHSJ had no cytotoxicity in Raw 264.7 cell. 2. All concentrations of SHSJ inhibited the production of NO in the Raw 264.7 cell stimulated with LPS. 3. All concentrations of SHSJ did not inhibit the production of TNF-$\alpha$ in the Raw 264.7 cell stimulated with LPS. 4. All concentrations of SHSJ inhibited the production of $PGE_{2}$ in the Raw 264.7 cell stimulated with LPS. 5. All concentrations of SHSJ did not inhibit the expression of COX-2 but concentrations of 50 ${\mu}g/ml$, 100 ${\mu}g/ml$ SHSJ inhibited iNOS expression in the Raw 264.7 cell stimulated with LPS. 6. Concentrations of 50 ${\mu}g/ml$, 100 ${\mu}g/ml$ SHSJ had the effect of blocking NF-${\kappa}B$ into nucleus in LPS-induced macrophage Raw 264.7 cell.

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버블을 이용한 파랑볼우럭 차단 효과 분석 (Analysis on the Bluegill Blocking Effects using Bubbles)

  • 강준구;김종태
    • 한국산학기술학회논문지
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    • 제18권2호
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    • pp.390-397
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    • 2017
  • 외래어종의 유입은 토종어류의 감소 및 수중생태계의 교란을 가져올 수 있기 때문에 어류의 차단 및 관리 방안은 반드시 필요하다. 따라서 본 연구에서는 외래어종의 유입을 차단하기 위해 버블을 이용한 어류 차단 시스템을 개발하였으며 실험수로를 제작하여 차단 가능성을 평가하였다. 버블 발생장치는 공기압축기로 공기를 발생시켜 버블커튼을 만든 후 어류를 차단하는 시스템이며 실험어류는 국내 외래어종인 파랑볼우럭을 대상으로 하였다. 파랑볼우럭의 크기는 0.10 m ~ 0.15 m이며 수심은 0.70 m를 유지하였다. 실험수로의 유속은 어류의 유영능력을 고려하여 3단계로(0.20 m/s, 0.10 m/s, 0.05 m/s) 나누어 실시하였다. 실험 결과 파랑볼우럭은 버블 적용 전 70.07%가 상류로 거슬러 올라가려는 움직임을 보였으며 하류를 서식처로 생각해 움직임이 거의 없는 개체를 고려하면 어류 소상률은 더 높을 것으로 판단된다. 그러나 차단시설을 설치할 경우 대부분의 어류가 버블커튼에 의해 다시 하류로 회귀하는 움직임을 보여 차단효과가 매우 높게 나타났다. 특히 버블을 종료할 경우 빠른 시간 내 다시 상류로 거슬러 올라간 것으로 보아 버블을 이용한 어류 차단효과는 뛰어난 것으로 판단된다.

광중합기용 팁과 시판용 청광 차단 렌즈 및 노란색 착색 렌즈의 청광 투과율 비교 융합 연구 (Convergence study of blue light transmittance comparison between tips for light curing machine and commercially available blue light blocking lenses and yellow tinted lenses)

  • 이숙정
    • 한국융합학회논문지
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    • 제12권7호
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    • pp.125-131
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    • 2021
  • 치과에서 사용횟수가 증가하고 있는 광중합형 레진 치료에는 강한 에너지를 가진 청색광이 필요하나, 그 빛은 산란 또한 커서 눈과 관련된 여러 부작용이 나타난다. 산란되는 빛에 노출되는 위험을 줄이고자 색깔 렌즈를 활용해보고자 하였다. 광중합기용 팁들과 청색광 빛의 차단에 효과가 있을 것으로 기대하는 시판용 노란색 계열의 청광 차단 렌즈와 노란색 염료로 착색한 노란색 렌즈를 UV-Vis 스펙트로미터 기기에 놓고 각각 청색광의 투과와 차단을 실험하였다. 결과로 광중합기용 팁들의 청광차단율 평균은 99.49%, 시판용 렌즈들 중 색 농도가 가장 높은 C 렌즈는 99.54%의 높은 청광차단율을 보였다. 노란색으로 착색한 렌즈의 경우에는 착색 농도가 가장 짙은 노란색 착색 C 렌즈가 87.57%의 청광차단율을 보였다. 레진 치료 시 광중합기용 팁과 함께 노란계열의 시판용 렌즈나 착색 렌즈를 착용한다면 청색광에 의한 눈과 관련된 부작용들을 줄일 수 있을 것으로 판단된다.

차단막 코팅을 이용한 광전기화학셀 효율 개선 (Improvement of Efficiency of Photoelectrochemical Cells by Blocking Layer Coatings)

  • 문병호;곽동주;박차수;성열문
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1485-1486
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    • 2011
  • A layer of $TiO_2$ thin film less than ~500nm in thickness, as a blocking layer, was coated by sol-gel method directly onto the anode electrode to be isolated from the electrolyte in dye-sensitized solar cells (DSCs). This is to prevent the electrons from back-transferring from the electrode to the electrolyte (I-/I3-). The effects of heat treatment conditions of the gel and as-coated film on the thickness and consolidation to substrate were studied. The flexible DSCs were fabricated with working electrode of Ti thin foil coated with blocking $TiO_2$ layer, dye-attached mesoporous $TiO_2$ film, gel electrolyte and counter electrode of Pt-deposited indium doped tin oxide/polyethylene naphthalate (ITO/PEN). The photo-current conversion efficiency of the cell was 5.3% ($V_{oc}=0.678V$, $J_{sc}=12.181mA/cm^2$, ff=0.634) under AM1.5, 100 mW/$cm^2$ illumination.

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Blocking Layers Deposited on TCO Substrate and Their Effects on Photovoltaic Properties in Dye-Sensitized Solar Cells

  • Yoo, Beom-Hin;Kim, Kyung-Kon;Lee, Doh-Kwon;Kim, Hong-Gon;Kim, Bong-Soo;Park, Nam-Gyu;Ko, Min-Jae
    • Journal of Electrochemical Science and Technology
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    • 제2권2호
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    • pp.68-75
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    • 2011
  • In this review, we have investigated the effect of $TiO_2$-based blocking layers (t-BLs), deposited on a transparent conductive oxide (TCO)-coated glass substrate, on the photovoltaic performance of dye-sensitized solar cells (DSSCs). The t-BL was deposited using spin-coating or sputtering technique, and its thicknesses were varied to study the influence of the thin $TiO_2$ layer in between transparent conducting glass and nanocrystalline $TiO_2$ (nc-$TiO_2$). The DSSC with the t-BL showed the improved adhesion and the suppressed charge recombination at a TCO glass substrate than those without the t-BL, which led to the higher conversion efficiency.

황금(黃芩)의 심장(心臟)에 대한 약리작용(藥理作用) (Pharmacological action of extracts of Scutellaria baicalensis on Cardiovascular System)

  • 노재열;이우주
    • 대한약리학회지
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    • 제11권2호
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    • pp.9-17
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    • 1975
  • The adrenergic blocking activity and refractory period of cardiac muscle on isolated rabbit atria were measured after administration of Scutellaria. In rabbits and cats the antiarrhythmic action of Scutellaria on atrial and ventricular arrhythmias produced by epinephrine or ouabain was examined and also compared with that of propranolol and quinidine. The alcoholic extract of Scutellaria produced a marked decrease in heart rate and contractile amplitude of the isolated rabbit atria. Pretreatment with Scutellaria rendered the atria to fail to respond to epinephrine, indicating that this crude drug possesses an adrenergic blocking activity. The extract produced a marked prolongation of the refractory period of atrial muscle. The extract effectively abolished the spontaneous arrhythmia occurring in the isolated rabbit atria. As propranolol and quinidine it also suppressed the atrial arrhythmia induced by ouabain. The extract prevented, as propranolol and quinidine, the induction of ventricular arrhythmia arising from excessive dose of epinephrine in anesthetized rabbits and cats. With regard to the ventricular arrhythmia induced by a continuous infusion of ouabain, the alcoholic extract of Scutellaria exerted some suppressive effect in anesthetized rabbits but no effect on cats. From the above results, it may be concluded that Scutellaria is effective against atrial and ventricular arrhythmias. The antiarrhythmic effects of this drug may be the result of adrenergic beta receptor blocking and cardiac depressive activities including prolongation of the refractory period of cardiac muscle.

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