• 한국ITS학회:학술대회논문집
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• 2010.05a
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• pp.66-71
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• 2010

• 한국ITS학회:학술대회논문집
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• v.2007 no.10
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• pp.270-275
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• 2007

• 한국ITS학회:학술대회논문집
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• 2002.11a
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• pp.125-128
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• 2002

• Geotechnical Engineering
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• v.12 no.3
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• pp.109-126
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• 1996

In this study, the chemical fluid considered is sodium chloride sloutions. The concentrations for the sodium chloride solutions are varied from 0 to 20%. A series of lab oratory triaxial tests are performed on the cylindrical specimens of sand bentonite mixture with different (5, 10, 15%) sodium chloride content solutions. Deformation(elastic modulus, E) and strength (cohesion, c', and angle of friction, f') parameters are obtained from the triaxial tests and they are expressed as functions of conf'ming pressure and sodium chloride solution concentrations. The stress-strain-strength behavior based on the above strength parameters is introduced to the finite element method with a residual flow procedure (RFP). By integrating a slope stability (limit equilibrium) procedure in the finite element method, factors of safety with time are computed.

• The Korean Journal of Physiology
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• v.2 no.1
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• pp.59-71
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• 1968

The uptake of phenolsulfonphthalein (PSP) and of paraaminohippuric acid (PAH) by cortical slices of the rabbit kidney was investigated while varying the composition of medium. The overall uptake of these substances displayed typical active transport characteristics and was significantly enhanced in presence of acetate. When the phosphate buffer was used the optimal pH was 7.4 for both substances. However, when the tris-buffer was used the optimal pH was 7.4 for PSP and 8.3 for PAH. Removal of $Na^+$ from the medium resulted in a significant reduction in the uptake. Similar results, though lesser in magnitude, were obtained when either $K^+\;or\;Ca^{++}$ was removed from the medium. However, there was no additive effect when $K^+\;and/or\;Ca^{++}$ were additionally removed from the $Na^+-free$ medium. The presence of ${NH_4}^+$ greatly reduced while $Li^+\;and\;Mg^{++}$ moderately reduced the uptake of both substances. However, choline had no effect. In substrate-leached slices, acetate greatly enhance the uptake of organic acids; but this action was not demonstrable in absence of $Na^+,\;K^+\;or\;Ca^{++}$.

• Korean Membrane Journal
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• v.4 no.1
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• pp.36-40
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• 2002

The diffusion coefficients of ions in the reverse transport system using the carrier mediated membrane were estimated from the diffusional membrane permeabilities and the ion activity in membrane system. In the aqueous alkali metal ions-membrane system diffusional flux of alkali metal ions driven by coupled proton was analyzed. The aqueous phase I contained NaOH solution and the aqueous phase II also contained NaCl and HCl mixed solution. The concentration of Na ions of both phases were $10^{0},\;10^{-1},\;10^{-2},\;5{\times}10^{-1}\;and\;5{\times}10^{-2}\;mol{\cdot}dm^{-3}$ and the concentration of HCI in aqueous phase II was always kept at $1{\times}10^{-1}\;mol{\cdot}dm^{-3}$. Moreover, the carrier concentration in liquid membrane was $10^{-2}\;mol{\cdot}dm^{-3}$. The results indicated that the diffusion coefficients depend strongly on the concentration of both phases electrolyte solution equilibriated with the membrane. The points were interpreted in terms of the energy barrier theory. Furthermore, eliminating the potential terms from the membrane equation was derived.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.200.1-200.1
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• 2003

The purpose of this study is to examine whether an brain to blood efflux system for taurine is present on the blood-brain barrier (BBB) or not and this efflux transport system is regulated by CNS cell damage with oxidative stress agent such as diethyl maleate (DEM) or tumor necrosis factor-a (TNF-${\alpha}$), by using the brain efflux index (BEI) method. The brain efflux index value is defined as the relative amount of test compound efflux from cerebrum compared with that of a reference compound, [$\^$14/C] carboxyinulin, which has limited BBB permeability. (omitted)

• Korean Journal of Medicinal Crop Science
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• v.28 no.1
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• pp.1-8
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• 2020

Background: This study was conducted to investigate the effects of NaCl concentration on the photosynthetic parameters, chlorophyll fluorescence and growth characteristics of Crepidiastrum sonchifolium. Methods and Results: As treatments, we subjected C. sonchifolium plants to four different concentrations of NaCl (0, 50, 100 and 200 mM). We found that the photosynthetic parameters maximum photosynthesis rate (P_{N max}), net apparent quantum yield (Φ), maximum carboxylation rate (V_cmax), and maximum electron transport rate (J_max) were significantly reduced at an NaCl concentration greater than 100 mM. In contrast, there was an increase in water-use efficiency with increasing NaCl concentration, although in terms of growth performances, leaf dry weight, root dry weight, stem length, and total dry weight all decreased with increasing NaCl concentration. Furthermore, leakage of electrolytes, as a consequence of cell membrane damage, clearly increased in response to an increase in NaCl concentration. Analysis of the polyphasic elevation of chlorophyll a fluorescence transients (OKJIP) revealed marked decrease in flux ratios (Φ_PO, Ψ_O and Φ_EO) and the PI_abs, performance index in response to treatment with 200 mM NaCl, thereby reflectings the relatively reduced state of photosystem II. This increase in fluorescence could be due to a reduction in electron transport beyond Q^-_A. We thus found that the photosynthetic parameters, chlorophyll fluorescence and growth characteristics of C. sonchifolium significantly increased in response to treatment with 200 mM NaCl. Conclusions: Collectively, the findings of this study indicate that C. sonchifolium shows relatively low sensitivity to NaCl stress, although photosynthetic activity was markedly reduced in plants exposed to 200 mM NaCl.

• BMB Reports
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• v.38 no.4
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• pp.481-485
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• 2005

The response of Spirulina (Arthrospira) platensis to high salt stress was investigated by incubating the cells in light of moderate intensity in the presence of 0.8 M NaCl. NaCl caused a decrease in photosystem II (PSII) mediated oxygen evolution activity and increase in photosystem I (PSI) activity and the amount of P700. Similarly maximal efficiency of PSII (Fv/Fm) and variable fluorescence (Fv/Fo) were also declined in salt-stressed cells. Western blot analysis reveal that the inhibition in PSII activity is due to a 40% loss of a thylakoid membrane protein, known as D1, which is located in PSII reaction center. NaCl treatment of cells also resulted in the alterations of other thylakoid membrane proteins: most prominently, a dramatic diminishment of the 47-kDa chlorophyll protein (CP) and 94-kDa protein, and accumulation of a 17-kDa protein band were observed in SDS-PAGE. The changes in 47-kDa and 94-kDa proteins lead to the decreased energy transfer from light harvesting antenna to PSII, which was accompanied by alterations in the chlorophyll fluorescence emission spectra of whole cells and isolated thylakoids. Therefore we conclude that salt stress has various effects on photosynthetic electron transport activities due to the marked alterations in the composition of thylakoid membrane proteins.

• The Korean Journal of Nuclear Medicine
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• v.32 no.2
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• pp.121-128
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• 1998

Purpose: $Na^+-K^+$ ATPase activity has been estimated by the degree of inhibition of cation transport by cardiac glycosides (ouabain) using Rb-86 as a substrate. The biological characteristisc of T1-201 is known to be similar to those of potassium as a transport substrate in the presence of glucose, insulin or phobol myristate acetate (PMA). The purpose of this study was to measure ouabain sensitive $Na^+-K^+$ ATPase activity using T1-201 and compare with that using Rb-86. Materials and Methods: Smooth muscle cells isolated from rat aorta or human placental umbilical artery were cultured, and used to measure cellular $Na^+-K^+$ ATPase activity. $Na^+-K^+$ ATPase activity was measured as a percentage decrease in cellular uptake of T1-201 or Rb-86 by ouabain under the presence of glucose, insulin or PMA in media. Results: $Na^+-K^+$ ATPase activity measured with T1-201, as a transport substrate, was not different from those measured with Rb-86 in rat or human smooth muscle cell preparation. Incubation with high concentration glucose resulted in about 30% decrease in enzyme activity. In contrast, insulin or PMA resulted in 10-70% or 28% increases from baseline activity, respectively. Conclusion: These results suggests that 71-201 could replace Rb-86 in measurement of ouabain sensitive $Na^+-K^+$ ATPase activity in vitro. High level of glucose concentration decreased cellular $Na^+-K^+$ ATPase activity, but insulin or PMA increased it.