• YAKHAK HOEJI
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• v.45 no.3
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• pp.282-286
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• 2001

To investigate the different mechanism between ATP and compound 48/80 (C$_{48}$80/)-induced histamine release, we observed effects of calcium antagonists in histamine release of rat peritoneal mast cells. Verapamil and diltiazem (voltage-dependent calcium channel blocker) and TMB-8 (a blocker of intracellular calcium release) significantly inhibited ATP-induced histamine release, but did not inhibit $C_{48}$80/-induced histamine release. Econazole (a blocker of receptor-operated calcium channel) dose-dependently inhibited both ATP and $C_{48}$80/-induced histamine release, but inhibitory effect of econazole in ATP-induced histamine release was more potent than that in $C_{48}$80/-induced histamine. EGTA dose-dependently inhibited ATP and $C_{48}$80/-induced histamine release, but $C_{48}$80/-induced histamine release was slightly inhibited by high concentrations (>2 mM) of EGTA. These results suggest that ATP-induced histamine release is related to broth intracellular calcium release and extracellular calcium influx via voltage-dependent calcium channel and receptor-operated calcium channel. $C_{48}$80/-induced histamine release is related to extracellular calcium influx, especially by receptor-operated calcium channel rather than voltage-dependent calcium channel.

• Journal of the Korean Chemical Society
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• v.39 no.1
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• pp.23-28
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• 1995

Differential-pulse cathodic stripping voltammetry was applied to the Sn(II)-cupferron complex in 0.1 M acetate buffer solution (pH 4.20). Effects of solution pH, ligand concentration, accumulation potential, and accumulation time on the reduction peak current for the adsorptive complex of Sn(II)-cupferron were investigated. Interferences by other metal cations that affected on reduction peak current were also discussed. The detection limit was 3.1${\times}$10-9 M (0.37 ppb) of Sn(II) with 60 seconds accumulation time. The relative standard deviation (n=8) for 5${\times}$10-8 M Sn(II) was 3.0%.

• Journal of the Korean Chemical Society
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• v.38 no.3
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• pp.234-240
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• 1994

Square-wave voltammetric behavior for uranium(VI)-cupferron complex was studied in 0.1 M acetate buffer solution(pH5.0). The optimum condition for square-wave voltammetric analysis of uranium was also investigated. The reduction of uranium(VI)-cupferron complex was found to be irreversible and only uranium(VI)-cupferron complex was adsorbed on the electrode surface during the deposition time. Detection limit of uranium(VI) was 7.9nM(2 ppb) where the deposition time was 30sec at -0.1 V vs. Ag/AgCl. The amount of uranium(VI)-cupferron complex adsorbed on the electrode surface was ${\Gamma}_{max} = (4.9{\pm}0.3){\times}10^{-10} mol{\cdot}cm^{-2}$.

• Journal of the Korean Chemical Society
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• v.37 no.12
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• pp.1053-1059
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• 1993

The determination of iron(Ⅱ), iron(Ⅲ) and total iron was studied by differential-pulse and Tast polarography in 0.1 M acetate buffer solution at pH 4.60, Half wave potentials of iron(Ⅱ)-DTPA and iron(Ⅲ)-DTPA complexes were -0.150V vs. SCE reference electrode. In the presence of DTPA the redox process of iron(Ⅱ) and iron(Ⅲ) was reversible. Linear calibration plots were obtained for iron(Ⅱ) and iron(Ⅲ) concentration of 0.2∼1.0 mM. The detection limits of iron(Ⅱ) and iron(Ⅲ)by Tast polarographic method were 0.05 mM and 0.07 mM, respectively.

• Journal of the Korean Chemical Society
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• v.37 no.7
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• pp.672-676
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• 1993

The complexation of bilirubin with zinc(II) and copper(II) ions was studied spectrophotometrically. In the zinc(II)-bilirubin (Zn-BR) system, complex is formed, but the copper(II) ion oxidizes bilirubin to biliverdin and then to the further oxidation products. The electrochemical reduction behavior of ZN-BR complex has been investigated with DC polarography and cyclic voltammetry. The three polarographic waves were obtained for the reduction of ZN-BR complex in DMF solution. Thde reduction current of the third wave was diffusion current, but that of the first and the second waves contained a little kinetic current.

• The Journal of the Korean bone and joint tumor society
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• v.8 no.2
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• pp.54-57
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• 2002

Since Keck described the tarsal tunnel syndrome in 1962, it has been one of the most frequently diagnosed of the entrapment neuropathies. Tarsal tunnel syndrome is usually of unknown origin, benign tumor may be one of the causes of tarsal tunnel syndrome. The object of the current study is to report our experience of surgical treatment about tarsal tunnel syndrome caused by neurilemmoma in 32-year-old female and by ganglion in 39-year-old male with a review of the literature.

• Bulletin of the Korean Chemical Society
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• v.19 no.5
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• pp.527-530
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• 1998

This paper presents the electrochemistry and molecular orbital (MO) picture of a series of conformationally-restricted thioxantone derivatives. A series of $C_2-substituted$ thioxanthones were examined to probe the electronic influence of the substituent on the electrooxidation and electroreduction sites (i.e., on the electron densities at the 10-and 9-positions), respectively. In the presence of "electrophoric" groups such as C=O and S, characteristic electrochemical reduction and oxidation responses are observed. The electrochemical reaction was diffusion-controlled, because the $I_p/{\upsilon}^{1/2}$ ratio was constant for the anodic and cathodic wave of thioxantone derivatives. These substituent effects are presented in terms of correlations of oxidation (or reduction) potentials with the highest occupied molecular orbital (HOMO), or lowest unoccupied molecular orbital (LUMO) energies, respectively. There is good correlation between energies of the HOMO vs. $E_{pa}^{(+)}$ and energies of the LUMO vs. $E_{pc}^{(-)}$. Frontier Molecular Orbital (FMO) is changed by the functional group of thioxanthones. FMO energy level was offered us the information about the electron transfer direction, and the coefficient of FMO was offered the information about the electron transfer position. Sulfur atom has an important effect on oxidation potential, $E_{pa}^{(+)}$ and the carbonyl carbon has an important effect on reduction potential, $E_{pc}^{(-)}$. Therefore we were appreciated that the contribution of sulfur atom for the $E_{pa}^{(+)}$ and HOMO energies is larger than the contribution of carbonyl group for the $E_{pc}^{(-)}$ and LUMO energies.

• Journal of Applied Reliability
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• v.18 no.2
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• pp.143-152
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• 2018

Purpose: In this paper, we propose calculation methods of Maintenance Float (M/F). Results of each method are compared and verified by using commercial tool (OPUS Suite). As modern weapon systems become more expensive, we need to find the most economical and efficient method to achieve the target operational availability (Ao). Methods: Three kinds of methods (Considering the number of CSP, Applying the Poisson distribution, and Applying M&S Tool) are used to find the number of M/F. Three methods (Considering the number of CSP, Applying the Poisson distribution, and Applying M&S Tool) were used to estimate the required number of M/F. The analysis results were verified by SIMLOX. The cost of equipment calculated by each analysis method was compared and the cause of the difference was analyzed. Conclusion: Ao and cost must be considered to find the optimal number of M/F. In general, it costs more to increase availability. But the cost is not necessarily proportional to Ao. Therefore, it is better to compare the calculation method and determine the final MF quantity.

• Journal of the Korean Chemical Society
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• v.37 no.9
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• pp.813-819
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• 1993

An ICP-AES system directly connected with a separation column was used in order to determine the trace elements in $UO_2$ powder promptly and reduce the volume of the waste solution. The outlet of a separation column, which was filled with Teflon powder ($330\;{\mu}m$) coated with tri-n-butyl phosphate (TBP) as extractant, was directly connected with sample injection tube of ICP-AES. Eleven elements including molybdenum in $UO_2$ powder were separated and determined simultaneously. Recoveries of these elements were $91{\sim}110%$ and these results were agreed with those of solvent extraction methods. This method was applicable to quality control in manufacturing nuclear fuel.

• Journal of Biomedical Engineering Research
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• v.33 no.2
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• pp.89-97
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• 2012

The purpose of this study is to develop the guideline of the physicochemical and mechanical properties evaluation for silicone gel filled breast implants. First of all, the use and development status for silicone gel filled breast implants were investigated, and then, standard and criteria about performance evaluation established by the international organizations such as ASTM, FDA guidance and ISO were examined. To evaluate the mechanical properties, data research and testing for breaking strength, elongation, tensile set, joint intensity, silicone gel cohesion, weight loss from heating, static rupture resistance, impact resistance test, fatigue test, and gel bleed were performed. On the other hand, to evaluate the physicochemical properties, volatile matter, extent of cross linking, heavy metals, and extractable were analyzed. In this study, results for general function, mechanical properties and physicochemical properties were examined and reviewed for the accordance with international standard, and objective and standardized guideline was provided.