• Korean Journal of Acupuncture
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• 제21권3호
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• pp.97-104
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• 2004

Objective We investigated the effect of Saururus chinensis (Lour.) Baill. aquacupuncture (SCB) on anaphylaxis in mice. Methods : We conformed compound 48/80-induced mesenteric mast cell degranulation, active systemic anaphylatic shock and histamine release. Also observed acetic acid-induced vascular permeability and anti-dinitrophenyl (DNP) IgE-mediated passive cutaneous anaphylaxis. Results : SCB inhibited mesenteric mast cell degranulation and active systemic anaphylatic shock induced by compound 48/80 dose-dependently. When SCB was pretreated by intra-peritoneal injection, the serum histamine levels were reduced. SCB also significantly inhibited acetic acid-induced vascular permeability. In addition, SCB showed a significant inhibitory effect on anti-dinitrophenyl (DNP) IgE-mediated passive cutaneous anaphylaxis. Conclusion : These results indicated that SCB inhibits anaphylatic reaction.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.78-88
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• 2007

In the present study a detailed examination of various porous media models for predicting filtration efficiency and pressure drop of diesel particulate filter (DPF), such as sphere-in-cell and constricted tube models, are attempted. In order for demonstrating their validities of correct estimation on permeability, geometry of property configurations common in commercial cordierite DPFs are correlated to the porous media flow models, and validations of predicted filtration efficiencies due to the use of different unit collectors are made with experiments. The result shows that the porosity, pore size and permeability of cordierite DPF can be successfully correlated by Kuwabara flow field with correction factor of 0.6. The unit collector efficiency predicted by sphere-in-cell model agrees very well with measurements in accumulation mode, whereas that by constricted tube model with significant prediction error.

• 멤브레인
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• 제12권1호
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• pp.51-53
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• 2002

Poly(vinyl alcohol) (PVA)/sulfosuccinic acid $(SSA)-H^+$ 막은 1가 이온 $Li^+, Na^+,K^ + 2$가 이온 $Mg^{2+}, Ca^{2+},Ba^{2+}, 3$가 이온 $Al^{3+}$로 치환하였다. 또한 $Li^{+}$의 경우 치환도를 화하였다. 금속이온치환의 효과를 알아보기 위하여 Diffusion cell을 이용한 메탄올투과도를 측정하였다. 메탄올투과도를 1가 이온의 경우는 'Salting-out'효과뿐 아니라 electrostatic 가교와 금속 이온의 반응성에 의존한다고 사료되었다. 또한 $Li^+$이온이 경우 치환도에 비례하여 메탄올 투과도가 감소하였는데 이는 'Salting-out'효과에 기인한다고 사료되어진다.

• Journal of Applied Biological Chemistry
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• 제62권1호
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• pp.101-107
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• 2019

The objectives of this study were to evaluate the anti-aging effects and investigate the effect of simulated gastrointestinal (GI) digestion on the anti-aging properties and intestinal permeation of the potential fish collagen hydrolysates (FCH). Therefore, procollagen synthesis, matrix metalloproteinase-1 (MMP-1) production, and Caco-2 cell permeability were analyzed before and after in vitro digestion for FCHs, low-molecular weight fractions (<1 kDa), and high molecular weight fractions (>1 kDa). After being subjected to GI digestion, the level of MMP-1 inhibition was maintained, although the procollagen production was significantly (>20%) lower with all samples. Also, the digested FCHs and their <1 kDa fraction yielded 9.1 and 13.8% increased peptide transport, respectively, compared to undigested samples. Based on the effective intestinal permeation and high digestive enzyme stability, the <1 kDa fraction of FCHs is a potential bioactive material suitable for anti-aging applications in the food and cosmetics industries.

• Korean Chemical Engineering Research
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• 제49권6호
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• pp.786-789
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• 2011

본 연구에서는 고체산화물연료전지에서 사용되고 있는 전해질의 직접탄소연료전지로의 적용가능성을 평가하기 위해 YSZ 전해질의 특성을 평가하였다. 전해질 층은 진공 슬러리 코팅 법을 사용하여 연료극 지지체위에 형성하였으며, 코팅 후 $1,400^{\circ}C$에서 5시간 동안 열처리하여 미세조직, 가스투과도 및 이온 전도도 측정을 통해 직접탄소연료전지로의 적용가능성을 확인하였다. YSZ 전해질은 얇고 치밀한 층을 형성하였으며 낮은 가스 투과도 값을 나타내었다. 이와같은 결과를 바탕으로 직접탄소 연료전지에 YSZ 전해질을 적용하였으며, 단위전지를 제작하여 $800^{\circ}C$에서 성능평가를 수행하였다.

• 한국세라믹학회지
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• 제39권1호
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• pp.86-91
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• 2002

고체 산화물 연료전지(Solid Oxide Fuel Cell; SOFC)는 무공해 청정에너지원으로서 기존의 발전방식을 대체할 차세대 에너지원으로 각광받고 있다. 고체산화물 연료전지의 구성요소는 크게 음극(anode), 양극(cathode), 전해질(electolyte)로 나뉘어 지는데 그 중 음극은 전극으로서의 역할은 물론 음극지지형인 경우 지지체 역할가지 수행해야 하기 때문에 아주 다양한 특성이 요구되어지고 있다. 그 중에서도 연료전지 성능의 최대 감쇄요인으로 지적되고 있는 분극저항을 줄이기 위해서는 높은 전기전도도와 높은 가스투과도가 요구되고있다. 본 연구에서는 음극 제조과정 중 첨가하는 기공 전구체의 종류에 따라 기판의 기공구조가 어떻게 바뀌는지 또 그로 인해 기판의 미세구조 및 전기전도도가 어떠한 영향을 받는지 관찰하였다. 결과 음극기판의 미세구조 및 전기전도도는 기공전구체의 종류에 따라 크게 달라졌으며 특히 이방성을 가지는 기공전구체의 사용은 전도성상의 단락 및 비효율적인 기공의 양산을 가져와 결과적으로 연료전지 성능을 악화시킬 것으로 예상된다.

• The Korean Journal of Physiology and Pharmacology
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• 제9권2호
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• pp.69-75
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• 2005

TRPM7, a cation channel protein permeable to various metal ions such as $Mg^{2+}$, is ubiquitously expressed in variety of cells including lymphocytes. The activity of TRPM7 is tightly regulated by intracellular $Mg^{2+}$, thus named $Mg^{2+}$-inhibited cation (MIC) current, and its expression is known to be critical for the viability and proliferation of B lymphocytes. In this study, the level of MIC current was compared between immature (WEHI-231) and mature (Bal-17) B lymphocytes. In both cell types, an intracellular dialysis with $Mg^{2+}$-free solution (140 mM CsCl) induced an outwardly-rectifying MIC current. The peak amplitude of MIC current and the permeability to divalent cation ($Mn^{2+}$) were several fold higher in Bal-17 than WEHI-231. Also, the level of mRNAs for TRPM7, a molecular correspondence of the MIC channel, was significantly higher in Bal-17 cells. The amplitude of MIC was further increased, and the relation between current and voltage became linear under divalent cation-free conditions, demonstrating typical properties of the TRPM7. The stimulation of B cell receptors (BCR) by ligation with antibodies did not change the amplitude of MIC current. Also, increase of extracellular $[Mg^{2+}]_c$ to enhance the $Mg^{2+}$ influx did not affect the BCR ligation-induced death of WEHI-231 cells. Although the level of TRPM7 was not directly related with the cell death of immature B cells, the remarkable difference of TRPM7 might indicate a fundamental change in the permeability to divalent cations during the development of B cells.

• 한국수소및신에너지학회논문집
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• 제22권1호
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• pp.42-50
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• 2011

The Montmorillonite (MMT) in the polymer matrix is expected to reduce methanol permeability due to the tortous path formed by dispersed silicate layers. However, the polymer composite membranes containing non-proton conducting inorganic particle tend to show low proton conductivity. To solve this problem, we used an ion exchange method to prepare functionalized MMT with various silane coupling agents. The modified MMT was randomly dispersed in sulfonated poly (arylene ether sulfone) (SPAES) matrix to prepare SPAES/modified MMT composite membranes. The performances of hybrid membranes for DMFCs application were investigated. The SPAES/modified composite membrane showed increased proton conductivity compared with the non-modified MMT composite membrane. However, the methanol permeability of the SPAES/modified membrane was higher than that of the non-modified MMT.

• Korean Chemical Engineering Research
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• 제58권1호
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• pp.21-28
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• 2020

The stem extract from Pyrus serotina var has natural antioxidant ability, but the extraction method does not result in a soluble compound in cosmetic formulations. This study investigated the cosmetic efficacy of the Pyrus serotina var stem extract and its epidermis permeation ability when combined with polymer micelles and a cell penetrating peptide. The total concentration of polyphenol compounds was determined to be 103.1644 ± 1.38 mg/g in the ethanol extract and 78.97 ± 1.45 mg/g in the hydrothermal extract. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effects were 55.94 ± 0.22% in the ethanol extract at 1,000 mg/L. Superoxide dismutase (SOD) activity rates were 104.05 ± 3.28% in the ethanol extract at 62.5 mg/L. The elastase inhibition rate was 67.21 ± 2.72% in the ethanol extract at 1,000 mg/L. An antimicrobial effect was observed in the Propionibacterium acnes strain. In the epidermal permeability experiment, it was confirmed that formulation of the polymer micelle containing the Pyrus serotina var stem extract and cell penetrating peptide (R6, hexa-D-arginine) showed small particle size and much better skin permeability. The cumulative amount of total Pyrus serotina var stem extract that penetrated to the skin over time increased over 24 hours in three formulations. The three formulations showed 51.61 ㎍/㎠ (Formulation 0), 75.97 ㎍/㎠ (Formulation 1) and 95.23 ㎍/㎠ (Formulation 2) skin penetration, respectively. Therefore, it was confirmed that the ethanol extracts of Pyrus serotina var stem showed good cosmetic efficacy and excellent epidermis permeation ability when combined with a polymer micelle and cell penetrating peptide. Thus, this extract has the potential to be used as a safe and natural cosmetic material in the future.

• 멤브레인
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• 제22권3호
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• pp.155-170
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• 2012

연료전지는 석유엔진과 비교하여 높은 전류밀도와 효율성, 그리고 친환경적이기 때문에 21세기 들어 대체 발전시스템으로서 각광받아왔다. 연료전지 시스템에서 고분자 전해질 막은 핵심부품으로써 현재 Nafion막이 연료전지시스템에서 사용 중이지만 높은 제조단가와 고온에서 낮은 전도도를 가지는 단점을 가지고 있다. 그러므로 많은 학자들이 낮은 제조단가, 높은 물리적 특성들을 달성하기 위한 연구를 진행하여 왔으며 연료전지의 상용화와 동시에 고성능의 연료전지의 개발을 위하여 많은 방법들이 개발되어 왔다. 그중, 유무기 복합막은 유기물과 무기물의 물성을 균일하게 조합할 수 있으므로 잠재성을 가지고 있는 제조방법이다. 본고에서는 다양한 무기물이 사용되어 제조된 유무기 복합막의 연구동향에 대하여 조사하였다.