• Title/Summary/Keyword: Cell membranes

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Preparation and Characterization of PVA/PAM Electrolyte Membranes Containing Silica Compounds for Direct Methanol Fuel Cell Application (실리카 화합물을 함유한 PVA/PAM 전해질 막의 제조 및 특성과 직접메탄올 연료전지로의 응용)

  • Yoon, Seok-Won;Kim, Dae-Hoon;Lee, Byung-Seong;Lee, Bo-Sung;Moon, Go-Young;Byun, Hong-Sik;Rhim, Ji-Won
    • Polymer(Korea)
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    • v.34 no.1
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    • pp.45-51
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    • 2010
  • This study focuses on the investigation of the possibility of the crosslinked poly (vinyl alcohol) membranes with both poly (acrylic acid-co-maleic acid) (PAM) and 3-(trihydroxysilyl)-1-propane-sulfonic acid (THS-PSA) for the direct methanol fuel cell application. In order to characterize the prepared membranes, the water content, the thermal gravimetric analysis, the ion exchange capacity, the ion conductivity and the methanol permeability measurements were carried out and then compared with the existing Nafion 115 membrane. The ion exchange capacity of the resulting membranes showed 1.6~1.8 meq./g membrane which was improved than Nafion 115, 0.91 meq./g membrane. In the case of the proton conductivity, the THS-PSA introduced membranes gave more excellent $0.042{\sim}0.056\;S{\cdot}cm^{-1}$ than Nafion 115, $0.024\;S{\cdot}cm^{-1}$. On the other hand, the methanol permeability was increased more than Nafion 115 for all the range of THA-PSA concentration.

Solanum Nigrum Polysaccharide (SNL) Extract Effects in Transplanted Tumor-bearing Mice - Erythrocyte Membrane Fluidity and Blocking of Functions

  • Yuan, Hong-Liang;Liu, Xiao-Lei;Liu, Ying-Jie
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10469-10473
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    • 2015
  • Background: Solanum nigrum L. has been used in traditional Chinese medicine because of its diuretic and antipyretic effects. The present research concerned effects of crude polysaccharides isolated from Solanum nigrum L. on erythrocyte membranes of tumor-bearing $S_{180}$ and $H_{22}$ in mice. Materials and Methods: Fluorescence-labeled red blood cell membranes were used with DPH fluorescence spectrophotometry to examine erythrocyte membrane fluidity, and colorimetry to determine degree of erythrocyte surface membrane blocking. Extent of reaction by tumor-bearing mice with the enzyme erythrocyte membrane bubble shadow detection of red cell membrane variation in the degree of closure before and after administration. Results: Solanum nigrum polysaccharide could significantly improve the $S_{180}$ and $H_{22}$ tumor-bearing mice erythrocyte membrane fluidity, compared with the control group, the difference was significant (p<0.01), SNL can significantly improve the red blood cell membrane and then $S_{180}$ tumor-bearing mice sealing ability, compared with the negative control group, the difference was significant(p<0.05, p<0.01). $H_{22}$ tumor-bearing mice can increase red cell membrane and then sealing ability, the difference was significant (p<0.05). Solanum nigrum polysaccharide degree of fluidity and blocking two transplanted tumors in mice restored the ability to raise the red cell membrane has a significant effect. Conclusions: Solanum nigrum L.-type mice transplanted tumor can affect the red blood cell membrane fluidity and re-closed, through the red cell membrane of red blood cells to enhance the immune function of the possibility of erythrocyte immunity against tumor formation garland provide experimental basis.

Paeonia lactiflora Inhibits Cell Wall Synthesis and Triggers Membrane Depolarization in Candida albicans

  • Lee, Heung-Shick;Kim, Younhee
    • Journal of Microbiology and Biotechnology
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    • v.27 no.2
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    • pp.395-404
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    • 2017
  • Fungal cell walls and cell membranes are the main targets of antifungals. In this study, we report on the antifungal activity of an ethanol extract from Paeonia lactiflora against Candida albicans, showing that the antifungal activity is associated with the synergistic actions of preventing cell wall synthesis, enabling membrane depolarization, and compromising permeability. First, it was shown that the ethanol extract from P. lactiflora was involved in damaging the integrity of cell walls in C. albicans. In isotonic media, cell bursts of C. albicans by the P. lactiflora ethanol extract could be restored, and the minimum inhibitory concentration (MIC) of the P. lactiflora ethanol extract against C. albicans cells increased 4-fold. In addition, synthesis of $(1,3)-{\beta}-{\small{D}}-glucan$ polymer was inhibited by 87% and 83% following treatment of C. albicans microsomes with the P. lactiflora ethanol extract at their $1{\times}MIC$ and $2{\times}MIC$, respectively. Second, the ethanol extract from P. lactiflora influenced the function of C. albicans cell membranes. C. albicans cells treated with the P. lactiflora ethanol extract formed red aggregates by staining with a membrane-impermeable dye, propidium iodide. Membrane depolarization manifested as increased fluorescence intensity by staining P. lactiflora-treated C. albicans cells with a membrane-potential marker, $DiBAC_4(3)$ ((bis-1,3-dibutylbarbituric acid) trimethine oxonol). Membrane permeability was assessed by crystal violet assay, and C. albicans cells treated with the P. lactiflora ethanol extract exhibited significant uptake of crystal violet in a concentration-dependent manner. The findings suggest that P. lactiflora ethanol extract is a viable and effective candidate for the development of new antifungal agents to treat Candida-associated diseases.

Microporous Polystyrene Membranes Produced via Thermally Induced Phase Separation (열적으로 유도된 상 분리에 의해 제조된 폴리스티렌 미세 다공성 막)

  • Song, Seung-Won;Torkelson, John M.
    • Membrane Journal
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    • v.5 no.3
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    • pp.119-128
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    • 1995
  • The effects of coarsening on microstructure formation in polystyrene-cyclohexane solutions and membranes made from them were studied by scanning electron miccoscopy(SEM). Thermal analysis of the polymer solutions was carried out with a differential scanning calorimeter and the binodal curve was determined from the onset temperature of the heat of demixing peak. Using thermally induced phase separation(TIPS) and a freeze drying technique, it was demonstrated that polymer membrane microstructure can be changed significantly by controlling coarsening time and quench route. For systems undergoing phase separation by spinodal decomposition, resulting in a well interconnecmd, microporous structure with nearly uniform pore sizes, it was found that extending the phase separation time prior m freezing and solvent removal can result in a significant increase in pore or cell size which is highly dependent on both quench depth and coarsening time. Also this study has revealed the important role of polymer concentration in dictating the material continuity of the membranes.

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Preparation and Characterization of PVA/PSSA-MA Electrolyte Membranes Containing Silica Compounds for Fuel Cell Application (실리카 화합물을 함유한 PVA/PSSA-MA 전해질 막의 제조 및 특성과 연료전지로의 응용)

  • Byun, Hong-Sik;Kim, Dae-Hoon;Lee, Byung-Seong;Lee, Bo-Sung;Yoon, Seok-Won;Rhim, Ji-Won
    • Membrane Journal
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    • v.18 no.4
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    • pp.336-344
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    • 2008
  • This manuscript deals with the investigation of the possibility of the crosslinked poly(vinyl alcohol) membranes with both poly(styrene sulfonic acid-co-maleic acid) and 3-(trihydroxysilyl)-1-propanesulfonic acid (THS-PSA) for the fuel cell application. The studies were focused on the characterization of the resulting membranes through water content, thermal gravimetric analysis, ion exchange capacity, ion conductivity and methanol permeability measurements and then compared with the existing Nafion membrane. Typically, the ion conductivity lied in the range of $10^{-3}$ to $10^{-2}\;S/cm$ while the methanol permeability showed the range of $10^{-6}$ to $10^{-8}\;cm^2/s$.

Effect on Fatty Acid Composition of red Blood Cell Membranes of supplement of Korean Pinenut Oil, rich in 5-Olefinic acids, in Normocholesterolemic and Atherosclerotic New Zealand White Rabbits (한국산 잣기름이 정상토끼 및 동맥경화증 유발 토기의 적혈구막 지방산조성에 미치는 영향)

  • 윤태헌;이상무
    • Journal of the East Asian Society of Dietary Life
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    • v.4 no.1
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    • pp.57-70
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    • 1994
  • The present study was carried out in normal and atherosclerotic New Zealand white(NZW) rabbits, to evaluate the effect of dietary supplementation with Korean pinenut oil, on the total fatty acid composition of red blood cell membranes. Erythrocyte fatty acids of chain lengths ranging fro 12 : 0 to 22 : 6$\omega$3 were identified. In study I, palmitic acid(16 : 0) was found to be the main erythrocyte membranes fatty acid, followed in turn by stearic(18 : 0), oleic(18 : 1), and linoleic acids(18 : 2$\omega$6). There was a large increase in the proportion of 20 : 4$\omega$6 in 10% pinenut oil group on days 40 and 80(compared with control), although the increase was not statistically significant. Most erythrocyte fatty acids were less affected by the types or levels of oils supplemented for periods fo 40 and 80days. In study II,at the end of the dietary treatment, the levels of 12 : 0, 14 : 0, 15 : 0 and 18 : 0 were significantly decreased in the 5% soybean oil/cholesterol group, whereas those of 12 : 0, 14 : 0 and 18 : 0 were significantly decreased, but that of 18 : 2$\omega$6 was significantly increased in the 10% soybean oil/cholesterol group, compared to the cholesterol group. No significant differences in fatty acid composition were seen between the pinenut oil/cholesterol group, whereas the 10% soybean oil/cholesterol group had significantly elevated 18 : 2$\omega$6, compared to the cholesterol group. The proportion of 18 : 4$\omega$6 was significantly raised in the 5% soybean oil/cholesterol and 5% pinenut oil/cholesterol group, and the content of 16 : 1$\omega$7 was significantly lowered in the 5% and 10% soybean/cholesterol groups, compared to the cholesterol group at 10 weeks supplementation. In studies I,II and III, the total proportions of saturated fatty acids were not significantly affected by the types of levels of oils supplemented throughout the study period.

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The effect of bacterial cellulose membrane compared with collagen membrane on guided bone regeneration

  • Lee, So-Hyoun;Lim, Youn-Mook;Jeong, Sung In;An, Sung-Jun;Kang, Seong-Soo;Jeong, Chang-Mo;Huh, Jung-Bo
    • The Journal of Advanced Prosthodontics
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    • v.7 no.6
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    • pp.484-495
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    • 2015
  • PURPOSE. This study was to evaluate the effects of bacterial cellulose (BC) membranes as a barrier membrane on guided bone regeneration (GBR) in comparison with those of the resorbable collagen membranes. MATERIALS AND METHODS. BC membranes were fabricated using biomimetic technology. Surface properties were analyzed, Mechanical properties were measured, in vitro cell proliferation test were performed with NIH3T3 cells and in vivo study were performed with rat calvarial defect and histomorphometric analysis was done. The Mann-Whitney U test and the Wilcoxon signed rank test was used (${\alpha}<.05$). RESULTS. BC membrane showed significantly higher mechanical properties such as wet tensile strength than collagen membrane and represented a three-dimensional multilayered structure cross-linked by nano-fibers with 60 % porosity. In vitro study, cell adhesion and proliferation were observed on BC membrane. However, morphology of the cells was found to be less differentiated, and the cell proliferation rate was lower than those of the cells on collagen membrane. In vivo study, the grafted BC membrane did not induce inflammatory response, and maintained adequate space for bone regeneration. An amount of new bone formation in defect region loaded with BC membrane was significantly similar to that of collagen membrane application. CONCLUSION. BC membrane has potential to be used as a barrier membrane, and efficacy of the membrane on GBR is comparable to that of collagen membrane.