• Journal of the Korean Society of Radiology
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• v.11 no.2
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• pp.157-165
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• 2017

The active transport characteristics of $K^+$ and $Na^+$ pumping system of cell membrane model which irradiated by high energy x-ray(linac 6MeV) was investigated. The cell membrane model used in this experiment was a $Na^+$ type sulfonated copolymerized membrane of styrene and divinylbenezene. The initial flux of the ion was increased with increase of both $H^+$ ion concentration. In this experiment range(pH 1.5-5, temperature $36.5^{\circ}C$), the initial flux of $K^+$ which was not irradiated by radiation was found to be from $2.09{\times}10^{-4}$ to $1.32{\times}10^{-3}mole/cm^2{\cdot}h$ and that of $Na^+$ from $7.09{\times}10^{-4}$ to $1.09{\times}10^{-3}mole/cm^2{\cdot}h$. the initial flux of $K^+$ which was irradiated by radiation was found to be from $21.0{\times}10^{-4}$ to $16.7{\times}10^{-3}mole/cm^2{\cdot}h$ and that of $Na^+$ from $62.0{\times}10^{-4}$ to $20.6{\times}10^{-3}mole/cm^2{\cdot}h$. The ratio $K^+$/$Na^+$ of membrane was about 1.10. And the driving force of pH of irradiated membrane was significantly increased about 9-20 times than membrane which was not irradiated. As active transport of $K^+$ and $Na^+$ of cell membrane model were abnormal, cell damages were appeared at cell.

• The Korean Journal of Physiology
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• v.29 no.2
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• pp.203-216
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• 1995

The effects of ${\alpha}_1-adrenergic$ receptor stimulation on membrane potential, intracellular $Na^+$ activity, and twitch force were investigated in ventricular muscles from guinea-pig hearts. Action potentials, intracellular $Na^+$ activity, and twitch force of ventricular papillary muscles were measured simultaneously under various experimental conditions. Stimulation of the ${\alpha}_1-adrenergic$ receptor by phenylephrine produced variable changes in action potential duration, a slight hyperpolarization of the diastolic membrane potential, a decrease in intracellular $Na^+$ activity, and a biphasic inotropic response in which a transient negative inotropic response was followed by a sustained positive inotropic response. These changes were blocked by prazosin, an antagonist of the ${\alpha}_1-adrenergic$ receptor, but not by atenolol, an antagonist of the ${\beta}-adrenergic$ receptor. This indicates that the changes in membrane potential, intracellular $Na^+$ activity, and twitch force are mediated by stimulation of the ${\alpha}_1-adrenergic$ receptor, but not by stimulation of ${\beta}-adrenergic$ receptor. The decrease in intracellular $Na^+$ activity was not observed in quiescent muscles, depending on the rate of the action pontentials in beating muscles. The intracellular $Na^+$ activity decrease was substantially inhibited by tetrodotoxin. However, the decrease in intracellular $Na^+$ activity was not affected by an inhibition of the $Na^+-K^+$ pump. Therefore, the decrease in intracellular $Na^+$ activity mediated by the ${\alpha}_1-adrenergic$ receptor appears to be due to a reduction of $Na^+$ influx during the action potential, perhaps through tetrodotoxin sensitive $Na^+$ channels. Our study also revealed that the decrease in intracellular $Na^+$ activity might be related to the transient negative inotropic response. The intracellular $Na^+$ activity decrease could lower intracellular $Ca^{2+}$ through the $Na^+-Ca^{2+}$ exchanger and thereby produce a decline in twitch force.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.2
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• pp.85-94
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• 1988

This experiment was carried out to obtain the basic data for removal the astringency and off-flavor in soybean milk, by means of soaking of soybean in NaOH and $NaHCO_3$ solutions. The changes of phenolic compounds in soybean during soaking were investigated with HPLC and also the changes of flavor and sensority of soybean milk, prepared from soaked soybean were studied. Phenolic compounds of soybean were identified as chlorogenic, p-hydroxybenzoic, p-coumaric, ferulic and gentisic acid and, chlorogenic acid content was greater than the others. The chlorogenic acid of soybean was mainly neutral type and the other compounds were almost acidic type. Up to 85% of the chlorogenic acid was removed by soaking of soybean in 0.1% of NaOH solution for 8 hrs. Phenolic compounds of soybean was almost removed by soaking in 0.1% of NaOH solution at $90^{\circ}C$ for 1 hr. Chemical composition of soybean milks prepared from soaking of soybean in water, 0.1% NaOH and 0.5% $NaHCO_3$ solution were similar. Hexanol content of beany flavor in soybean milk was increased by soaking of soybean in NaOH solution, where as hexanal, propanal, pentanal contents were removed up to 60%. Color of soybean prepared from soaking of soybean in NaOH solution at high temperature were deep yellow but were high whiteness in soybean milk prepared from soaking of soybean in water at low temperature. Sensority of soybean milk prepared from soaking of soybean in 0.1% of NaOH solution at $90^{\circ}C$ for 1 hr was more favorable than the others.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.48.2-48.2
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• 2015

van Dokkum and Conroy revisited the strong Na I lines at $8200{\AA}$ found in some giant elliptical galaxies and interpreted it as evidence for bottom-heavy initial mass function. Jeong et al. later found a lot of galaxies showing strong Na D doublet absorption line at $5900{\AA}$ (Na D excess objects; a.k.a. NEOs) and showed that their origins can be different for different types of galaxies. While the excess in Na D seems related with interstellar medium in late-type galaxies, smooth-looking early-type NEOs suggest no compelling sign of ISM contributions. To test this finding, we measured doppler shift in the Na D line. We hypothesized that ISM is more likely to show blueshift due to outflow caused by either star formation or AGN activities. In order to measure the doppler shift, we tried both Gaussian and Voigt functions to fit each galaxy spectrum near the Na D line. We found that Voigt profiles reproduce the shapes of the Na D lines markedly better. Many of late-type NEOs clearly show blueshift in their Na D lines, which is consistent with the former interpretation that the Na D excess found in them is related with star formation-caused gas outflow. On the contrary, early-type NEOs do not show any notable doppler component, which is also consistent with the interpretation of Jeong et al. that the Na D excess in early-type NEOs is likely not related with ISM activities but purely stellar in origin.

• Bulletin of the Korean Chemical Society
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• v.16 no.3
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• pp.265-269
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• 1995

Complexation of ortho-xylyl-17-crown-5 (X17C5) with alkali metal ions in acetonitrile was studied by 7Li and 23Na NMR spectroscopy. The complex formation constants of X17C5 with LiI, LiSCN, NaI, and NaSCN were determined by investigating the changes in the chemical shifts as a function of the concentration ratio of X17C5 to metal ion. It was found that X17C5 forms 1:1 complex with Li+ and Na+ ions and the log Kf's for the complexation with LiI, LiSCN, NaI, and NaSCN were determined to be 2.88, 2.43, 2.53, and 2.30, respectively. In particular, the kinetics of complexation of X17C5 with Na+ was investigated by the method of 23Na NMR lineshape analysis. Activation energies were determined from Arrhenius plot of the resultant rate constant data to be 25.4 kJ/mol for NaI and 15.1 kJ/mol for NaSCN. Other kinetic parameters were also calculated by employing the Eyring equation. The decomplexation rates measured were 1.82 × 104 M-1s-1 for NaI and 1.50 × 104 M-1s-1 for NaSCN. It is concluded that the decomplexation mechanism is predominantly a bimolecular cation exchange for both cases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.315-316
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• 2006

Dense $0.95(Na_{0.5}K_{0.5})NbO_3-0.05LiTaO_3$ (NKN-LT) ceramics were developed by conventional sintering process. Sintering temperature was lowered by adding $Na_2O$ as a sintering aid. The electrical properties of NKN-LT ceramics were investigated as a function of $Na_2O$ concentration. When the sample sintered at $1000^{\circ}C$ for 4h with the addition of 1 mol% $Na_2O$, electromechanical coupling factor ($k_p$) and piezoelectric coefficient ($d_{33}$) of NKN-LT ceramics were found to reach the highest values of 0.43 and 190 pC/N, respectively.

• YAKHAK HOEJI
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• v.44 no.3
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• pp.205-212
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• 2000

The effect of BRL 34915, a $K^{+}$ channe$Na^{+}$l opener, on renal function was investigated in anesthetized dog. BRL 34915, when given into the vein, elicited the decrease of urine volume accompanied with the reduction of renal plasma flow (RPF), osmolar clearance ($C_{osm}$) and amounts of sodium excreted into urine ($E_{na}$), whereas reabsorption rate of sodium in renal tubules ($R_{na}$), ratio of $K^{+}$ against $Na^{+}$ in urine ($K^{+}$ /$Na^{+}$) were elevated significantly with a partial fall of mean arterial pressure (MAP). BRL 34915 injected into a renal artery produced the diuretic action along with the increase in RPF $C_{osm}$, $E_{na}$ and amounts of potassium excreted in urine ($E_{k}$), and the decrease in $R_{na}$, reabsorption rate of potassium in renal tubules ($R_{k}$), free water clearance ($C_{H20}$) and $K^{+}/Na^{+}$ ratio in only ipsilateral kidney, however changes of the renal function were not observed in control kidney. BRL 34915 given into carotid artery exhibited the same aspect as changes of renal function induced by intravenous BRL 34915. These results suggest that BRL 34915 has dual effects, renally acting diuretic and centrally acting antidiuretic action.n.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.635-641
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• 2020

In this study, phase equilibria and formation behaviors of methane hydrate containing mono-ethylene glycol (MEG) and salts (sodium chloride, NaCl; sodium bromide, NaBr; sodium iodide, NaI) are investigated. Equilibrium conditions of methane hydrate containing MEG and salts are measured in a temperature range 272~283 K and a pressure range 3.5~11 MPa. Hydrate inhibition performance in the presence of additives can be summarized as follows: methane hydrate containing (5 wt% NaCl + 10 wt% MEG) > (5 wt% NaBr + 10 wt% MEG) > (5 wt% NaI + 10 wt% MEG). Formation behaviors of methane hydrate with MEG and salts are investigated for analyzing the induction time, gas consumption amount and growth rate of methane hydrates. There are no significant changes in the induction time during methane hydrate formation, but the addition of MEG and salts solution during hydrate formation can affect the gas consumption amount and growth rate.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.2
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• pp.115-122
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• 2010

In this study, the removal of Cs and Tc from a simulated fission products (FP) solution which were co-dissolved with U during the oxidative-dissolution of spent fuel in a mixed carbonate solution of $(Na_2CO_3-NaHCO_3)-H_2O_2$ was investigated by using a selective precipitation method. As Cs and Tc might cause an unstable behavior due to the high decay heat emission of Cs as well as the fast migration of Tc when disposed of underground, it is one of the important issues to removal them in views of the increase of disposal safety. The precipitation of Cs and Re (as a surrogate for Tc) was examined by introducing sodium tetraphenylborate (NaTPB) and tetraphenylphosponium chloride (TPPCl), respectively. Precipitation of Cs by NaTPB and that of Re by TPPCl were completed within 5 minutes. Their precipitation rates were not influenced so much by the temperature and stirring speed even if they were increased by up to $50^{\circ}C$ and 1,000 rpm. However, the pH of the solution was found to have a great influence on the precipitation with NaTPB and TPPCl. Since Mo tends to co-precipitate with Re at a lower pH, especially, it was effective that a selective precipitation of Re by TPPCl was carried out at pH of above 9 without co-precipitation of Mo and Re. Over 99% of Cs was precipitated when the ratio of [NaTPB]/[Cs]>1 and more than 99% of Re, likewise, was precipitated when the ratio of [TPPCl]/[Re]>1.

• The Korean Journal of Pharmacology
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• v.14 no.1_2
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• pp.1-11
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• 1978

The $Na^+$-and $K^+$-induced $Ca^{++}$ release was measured isotopically by Milipore filter technique in mitochondria isolated from rabbit ventricles. The release of $Ca^{++}$ from mitochondria could be induced by 1-3 mM of $Na^+$ added in incubating medium under the presence of 0.5mM EGTA to prevent the released $Ca^{++}$ from rebinding with mitochondrial membrane. The amount of $Ca^{++}$ released was increased by increasing the concentration of $Na^+$ added. 100mM $K^+$, in itself, did not induce the $Ca^{++}$ release from cardiac mitochondria, the $Na^+$-induced $Ca^{++}$ release, however, was potentiated by the presence of $K^+$. The potentiation of $Na^+$-induced $Ca^{++}$ release by $K^+$ was proportional to the $Na^+/K^+$ ratio presented in the incubating medium. Among the monovalent cations other than $Na^+$, the release of $Ca^{++}$ from cardiac mitochondria was shared only by $Li^+$. The $Na^+$-induced $Ca^{++}$ release could be also observed in the mitochondria isolated from liver and kidney. However, the $Na^+$ sensitivity was somewhat lower in liver and kidney mitochondria than in heart mitochondria. The release of $Ca^{++}$ induced by $Na^+$ in the mitochondria isolated from the experimentally produced failured heart was not different from that in the normal heart mitochondria, and was not directly modified by $10^{-6}{\sim}10^{-5}$ M of Ouabain. From the experiments, it was suggested that the $Ca^{++}$ released from mitochondria by $Na^+$ could be used in excitation-contraction coupling process to initiate the contraction of the cardiac myofibrils. Futhermore, it appeared that the phenomenon of $Ca^{++}$ release from cardiac mitochondria by $Na^+$ and $K^+$ might be related to the inotropic effect of digitalis glycoside which could bring about the increase of $Na^+$ or the reduction of $K^+$ intracellulary through the inhibition of $Na^+$, $K^+$-ATPase.