• The Journal of Korean Medicine
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• v.21 no.4
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• pp.193-203
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• 2000

Objectives : Hindered barrier function of vascular endothelium has been implicated in the initiation and progression of degenerative vascular diseases such as atherosclerosis. In this study, the effect of Sunghyangchungisan(SHCS) as a protectant against oxidant-induced destruction of endothelial barrier function was assessed. Methods : Toward this end, endothelial cells derived from the human umbilical vein were cultured as monolayers on permeable membrane filters. Endothelial permeability was monitored by measuring transendothelial electrical resistance and movement of low density lipoprotein (LDL) across the endothelial monolayer. Results : Along with increased movement of LDL, $H_2O_2$-induced increase in endothelial permeability was paralleled by a decrease in transendotheliaI electrical resistance. The effect of $H_2O_2$ was mimicked by phorbol 12-myristate 13-acetate (PMA), a potent activator of proteinkinase C. Calphostin-C, a protein kinase C inhibitor, effectively blocked the increase in endothelial permeability induced by $H_2O_2$ or PMA, indicating that activation of protein kinase C is associated with the $H_2O_2-induced$ permeability change. SHCS effectively protected the endothelial monolayer against $H_2O_2-induced$ increase in permeability, whereas, it did not affect PMA-induced change. Forskolin, a potent activator of adenylyl cyclase, antagonized $H_2O_2$ to increase endothelial permeability. In addition, in ${H_2O_2}-treated$ cens, intracenular cAMP concentration was significantly decreased, indicating that impaired cAMP production as well as activation of proteinkinase C is a mechanism underlying ${H_2O_2}>-induced$$H_2O_2$ with regard to its effect on intracellular cAMP content. However, SHCS itself did not affect resting cAMP concentration in endothelial cells. Conclusions : These results suggest that SHCS might operate as an effective protectant against oxidant-induced destruction of endothelial barrier function. The mechanism does not appear to involve direct interaction with protein kinase C- or cAMP-associated signaling mechanism.

• Membrane Journal
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• v.24 no.6
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• pp.423-430
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• 2014

PTMSP/LDH composite membranes were prepared by adding 0, 1, 3, and 5 wt% LDH contents to PTMSP. The gas permeability and selectivity for $H_2$, $N_2$, $CH_4$, $C_3H_8$, $n-C_4H_{10}$ were investigated as a function of LDH content. As LDH content of PTMSP/LDH composite membranes increased to 5 wt%, the gas permeability for $H_2$ and $N_2$ gradually decreased, while $n-C_4H_{10}$ permeability rapidly increased. The gas permeability for $CH_4$ and $C_3H_8$ was found to decrease for the membranes with LDH content range of 0~3 wt%, however increase in the range of 3~5 wt%. As LDH content of PTMSP/LDH composite membranes increased to 5 wt%, the selectivity of membranes gradually increased for $H_2$, $N_2$, $CH_4$, $C_3H_8$, $n-C_4H_{10}$ over $H_2$, $N_2$. However the selectivity for $C_3H_8$ and $n-C_4H_{10}$ over $CH_4$ increased in the range of LDH content 0~3 wt% but decreased in the range of 3~5 wt%. The $CH_4$ and $n-C_4H_{10}$ selectivity over $H_2$ and $N_2$ increased as $CH_4$ and $n-C_4H_{10}$ permeability increased. The $n-C_4H_{10}$ selectivity over $CH_4$ increased with increasing $n-C_4H_{10}$ permeability up to 182,000 barrer and decreased above 182,000 barrer of $n-C_4H_{10}$ permeability. The $C_3H_8$ selectivity over $H_2$ and $N_2$ was found to decrease as the $C_3H_8$ permeability increased from 46,000 to 50,000 barrer, but to increase with increasing permeability from 50,000 to 52,300 barrer and decrease again with increasing permeability from 52,300 to 60,000 barrer. The $C_3H_8$ selectivity over $CH_4$ was found to decrease with increasing $C_3H_8$ permeability up to 52,300 barrer but increase above 52,300 barrer.

• Membrane Journal
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• v.20 no.1
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• pp.47-54
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• 2010

The PDMS-NaYzeolite composite membranes were prepared by adding 1~40 wt% NaYzeolite to PDMS. In order to investigate the characteristics of these membranes, we used the analytical methods such as FT-IR, $^1H$-NMR, and SEM. The permselectivity of $H_2$ and $N_2$ gases through the composite membranes was studied as a function of NaYzeolite contents. The permeability and selectivity ($H_2/N_2$) of PDMS membrane increased as the gas permeation pressure increased. The permeability of the PDMS-NaYzeolite composite membranes increased when 1~10 wt% NaYzeolite was added, and then decreased at higher wt% as NaYzeolite content increased. The selectivity ($H_2/_2$) of PDMS-NaYzeolite composite membranes decreased when 1~2 wt% NaYzeolite was added, and then increased as NaYzeolite content increased. As the $H_2$ permeability increased, the selectivity ($H_2/N_2$) of PDMS-NaYzeolite composite membranes decreased at 0~2 wt% and 10~40 wt% NaYzeolite contents, increased at 2~10 wt% NaYzeolite content.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.1
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• pp.51-58
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• 2006

The promoting effect of hydrogen peroxide ($H_2O_2$) against the cytotoxicity of 1-methyl-4-phenylpyridinium ($MPP^+$) in differentiated PC12 cells was assessed by measuring the effect on the mitochondrial membrane permeability. Treatment of PC12 cells with $MPP^+$ resulted in the nuclear damage, decrease in the mitochondrial transmembrane potential, cytosolic accumulation of cytochrome c, activation of caspase-3, increase in the formation of reactive oxygen species (ROS) and depletion of GSH. Addition of $H_2O_2$ enhanced the $MPP^+-induced$ nuclear damage and cell death. Catalase, Carboxy-PTIO, Mn-TBAP, N-acetylcysteine, cyclosporin A and trifluoperazine inhibited the cytotoxic effect of $MPP^+$ in the presence of $H_2O_2$. Addition of $H_2O_2$ promoted the change in the mitochondrial membrane permeability, ROS formation and decrease in GSH contents due to $MPP^+$ in PC12 cells. The results show that the $H_2O_2$ treatment promotes the cytotoxicity of $MPP^+$ against PC12 cells. $H_2O_2$ may enhance the $MPP^+$-induced viability loss in PC12 cells by promoting the mitochondrial membrane permeability change, release of cytochrome c and subsequent activation of caspase-3, which is associated with the increased formation of ROS and depletion of GSH. The findings suggest that $H_2O_2$ as a promoting agent for the formation of mitochondrial permeability transition may enhance the neuronal cell injury caused by neurotoxins.

• Journal of Pharmaceutical Investigation
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• v.30 no.2
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• pp.99-105
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• 2000

This study compared the permeability of $[^3H]taurine,\;[^3H]phenylalanine,\;and\;[^3H]oxytocin$ through the blood-brain barrier (BBB) in mice and rats with common carotid artery perfusion (CCAP) method that modified internal carotid artery perfusion (ICAP) method. External carotid artery (ECA) was cannulated with coagulating pterygopalatine artery (PPA) in ICAP method, while CCA was cannulated without coagulating PPA in CCAP method. Also, for evaluation of BBB permeability of drugs in mice and rats, we used intravenous injection technique. The results of CCAP method in mice at a perfusion flow-rate of 2 ml/min, the brian volume of distribution $(V_D)$ of $[^{14}C]sucrose,\;[^3H]taurine,\;[^3H]phenylalanine,\;and\;[^3H]oxytocin$ were similar to the result of ICAP method in rats at perfusion flow rate of 4 ml/min. The area under the plasma concentration-time curve and brain uptake of $[^3H]taurine$ by intravenous injection technique, were $65.5{\pm}9.7%ID^*min/ml\;and\;0.515{\pm}0.093%ID/g$, respectively, in mice, and the corresponding values were $8.00{\pm}0.03%ID^*min/ml\;and\;0.052{\pm}0.003%ID/g$ in rats. But the BBB permeability surface-area product of $[^3H]taurine$ was similar between mice and rats. In conclusion, the CCAP method in mice was simple, fast and comparable to ICAP method in rats for drug permeability through the BBB.

• Korean Journal of Food Science and Technology
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• v.21 no.2
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• pp.235-237
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• 1989

Water vapor permeability of plastic films was measured by Electric tester and Cup tester and the data of the two were compared. Regardless of the testing method, water vapor permeability measured by two methods showed consistent results. By these methods, water vapor permeability of polyethylene film was $21.25g/m^2$. 24h and $5.4g/m^2$. 24h for 0.045mm and 0.08mm thickness, respectively. The water vapor permeability of casted polypropylene film was 14.93 and $14.90g/m^2$. 24h for Electric tester and Cup tester, respectively. In conclusion, the data obtained by Cup tester was consistent with those of the Electric tester. The Cup tester was certified to perform the water vapor pormeability testing method.

• Membrane Journal
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• v.22 no.5
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• pp.342-351
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• 2012

In this study, PTMSP[poly(1-trimethylsilyl-1-propyne)]/PDMS[poly(dimethylsioxane)]-NaY zeolite and PTMSP/PDMS-NaA zeolite composite membranes were made to incorporate zeolite into PTMSP/PDMS graft copolymer in order to improve the selectivity and thermal stability, the drop of permeability by physical aging effect during long period of time for the PTMSP membrane. To investigate the physico-chemical characteristics of composite membranes, the analytical methods such as FT-IR, $^1H$-NMR, TGA, SEM, and GPC have been utilized. The gas permeability and selectivity properties of $H_2$ and $N_2$ were evaluated. The permeability of the PTMSP/PDMS-NaY zeolite and PTMSP/PDMS-NaA zeolite composite membranes than PTMSP/PDMS graft copolymer membrane increased, increased as zeolite content increased. On the contrary, the selectivity ($H_2/N_2$) of the composite membranes decreased as zeolite content increased. PTMSP/PDMS-NaA zeolite composite membrane showed better permeability and separation factor than PTMSP/PDMS-NaY zeolite composite membrane.

• Journal of the Korean institute of surface engineering
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• v.40 no.6
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• pp.245-249
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• 2007

Amorphous IZO films were deposited on PET substrate by DC magnetron sputtering without substrate heating. In order to investigate effect of reactive gas addition on film properties, 0.2-0.4% of $H_2$ or $O_2$ gas was introduced during the deposition. Deposited IZO films were evaluated with mechanical property, electrical property, and water permeability. In the case of $H_2$ gas addition, mechanical property showed clear degradation compared to $O_2$ gas. In the case of $O_2$ gas, water permeability of the IZO film was increased compared to $H_2$ gas which could be attributed to the low adhesion of the film caused by bombardment of high energy negative oxygen ion. As a result, it is confirmed that water permeability of the film could be strongly affected by adhesion of the film.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.35-41
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• 2020

(-)-epigallocatechin-3-gallate (EGGG), a flavonoid found in green tea, is known to have low bioavailability. In this study, we determine whether piperine, a natural bioenhancer, can increase the absorption rate of EGCG. Using a Caco-2 cell monolayer, permeability experiments were performed in Hanks' balanced salt solution (HBSS) and EGCG stability was adjusted to pH 6.5 and pH 5.5 by ascorbic acid treatment. When HBSS was adjusted to pH 6.5, EGCG remained at 94.78% for up to 2 h and remained at 86.04% after 4 h and the net efflux decreased compared to the control. As a result, uptake was significantly increased in the piperine co-administered group compared to the EGCG-alone group, showing that piperine increased the permeability of EGCG in the Caco-2 cell monolayer. These results suggest that piperine inhibits EGCG glucuronidation and efflux, allowing for greater absorption of EGCG.

• Journal of the Korean institute of surface engineering
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• v.53 no.5
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• pp.201-206
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• 2020

A SiOxCy(-H) thin film was synthesized by atmospheric pressure dielectric barrier discharge(APDBD), and a SiO₂-like layer was formed on the surface of the film by oxidation treatment using oxygen plasma. Hexamethylcyclotrisiloxane was used as a precursor for the SiOxCy(-H) synthesis, and He gas was used for stabilizing APDBD. Oxygen permeability was evaluated by forming an oxidized SiOxCy(-H) thin film on a PET film. When the single-layer oxidized SiOxCy(-H) film was coated on the PET, the oxygen gas permeability decreased by 46% compared with bare PET. In case of three-layer oxidized SiOxCy(-H) film, the oxygen gas permeability decreased by 73%. The oxygen permeability was affected by the thickness of the SiO₂-like layer formed by oxidation treatment rather than the thickness of the SiOxCy(-H) film. The excellent corrosion resistance was demonstrated by coating an oxidized SiOxCy(-H) thin film on the silver-coated aluminum PCB for light emitting diode (LED).