• Analytical Science and Technology
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• v.20 no.1
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• pp.55-60
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• 2007

A sensitive technique for the determination of trace Cu(II) in various samples after the column preconcentration by adsorbing its N-benzoylphenylhydroxylamine (BPHA) onto benzophenone was developed. Several experimental conditions such as the pH of the sample solution, the amount of chelating agent, the amount of benzophenone, and the flowrate of sample solution and so forth were optimized. The interfering effects of diverse concomitant ions were investigated. Fe(III) and $CN^-$ interfered with more seriously than any other ions. However, the interference by these ions could be overcome sufficiently by adjusting the added volume of 0.01M BPHA to 10 mL. The dynamic range, the correlation coefficient ($r^2$) and the detection limit obtained by this proposed technique were 5.0~120 ng/mL, 0.9974, and 2.1 ng/mL, respectively. For validating this proposed technique, the aqueous samples (stream water, reservoir water, and wastewater), the plastic sample and the diluted brass sample were used. Recovery yields of 93~102% were obtained. These measured data were not different from ICP-MS data at 95% confidence level. This method was also validated by the rice flour CRM (normal, fortified) samples. Based on the results from the experiment, it was found that this proposed technique could be applied to the determination of Cu(II) in various real samples.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.21 no.4
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• pp.427-438
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• 2023

Thermodynamic sorption modeling can enhance confidence in assessing and demonstrating the radionuclide sorption phenomena onto various mineral adsorbents. In this work, Ca-montmorillonite was successfully purified from Bentonil-WRK bentonite by performing the sequential physical and chemical treatments, and its geochemical properties were characterized using X-ray diffraction, Brunauer-Emmett-Teller analysis, cesium-saturation method, and controlled continuous acid-base titration. Further, batch experiments were conducted to evaluate the adsorption properties of Cs(I) and Sr(II) onto the homoionic Ca-montmorillonite under ambient conditions, and the diffuse double layer model-based inverse analysis of sorption data was performed to establish the relevant surface reaction models and obtain corresponding thermodynamic constants. Two types of surface reactions were identified as responsible for the sorption of Cs(I) and Sr(II) onto Ca-montmorillonite: cation exchange at interlayer site and complexation with edge silanol functionality. The thermodynamic sorption modeling provides acceptable representations of the experimental data, and the species distributions calculated using the resulting reaction constants accounts for the predominance of cation exchange mechanism of Cs(I) and Sr(II) under the ambient aqueous conditions. The surface complexation of cationic fission products with silanol group slightly facilitates their sorption at pH > 8.

• Bulletin of the Korean Chemical Society
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• v.23 no.1
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• pp.81-85
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• 2002

A new di-N-cyanoethylated 14-membered tetraaza macrocycle 1,8-bis(2-cyanoethyl)-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane $(L^2)$ and its nickel(II) complex $[NiL^2(OAc)]^+$ have been prepared. The square-planar complex $[NiL^2](C IO_4)_2$ can be prepared by addition of $HClO_4$ to a hot aqueous solution of $[NiL^2(OAc)]^+$ The Ni-N (tertiary amino group) bond distances $(2.008{\AA})$ of $[NiL^2](C IO_4)_2$ are relatively long, and the complex exhibits a d-d transition band at unusually long wavelength (ca. 515 nm). The complex $[NiL^2](C IO_4)_2$ rapidly reacts with acetate ion or ethylenediamine (en) to produce $[NiL^2(OAc)]^+$ or [Ni(en)_3]^{2+}$, respectively, and is readily decomposed in NaOH (0.01 M) solution. The chemical properties of $[NiL^2]^{2+}$ as well as its synthetic procedure are quite different from those for other related 14-membered tetraaza macrocyclic complexes. Effects of the N-cyanoethyl and C-methyl groups on the properties of $L^2$.

• Journal of Chest Surgery
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• v.26 no.10
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• pp.743-748
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• 1993

Alterations in thyroid function test results are frequently seen in patients with nonthyroidal illness & correlate with the severity of the illness & prognosis. We studied thyroid hormone changes in 14 patients received cardiopulmonary bypass[CPB]. All patients were biochemical euthyroidism preoperatively. TSH[Thyroid Stimulating Hormone] level reached its nadir[0.46 $\pm$ 0.11 ulU/ml, P<0.0005] at 12 hours after the start of CPB & showed elevating pattern to the preoperative level thereafter. FT4[Free Thyroxine] reached to its nadir[10.16$\pm$ 1.17 pmol/L, P<0.01] at POD[Post Operative Day] #4 & reached to the preoperative level at POD #7. Mean serum TSH & FT4 concentration were within normal limits[P>0.25] during CPB & thereafter. TT3[Total Triiodothyronine] reached to its nadir[38.6 $\pm$ 8.4 ng/dl, P<0.001] at 30 minutes after the start of CPB & remained low[P<0.05] throughout the study period. The patients whose recovery was uneventful[Group I] had higher serum TSH, TT3 levels[P<0.05] than who had complications or died[Group II]. Group I showed the elevating pattern of TSH, TT3 at POD #4, but Group II failed to show such elevating pattern. In Group I, FT4 was within normal limits[P>0.5] throughout the study period, and also within normal limits[P>0.1] in Group II.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3658-3662
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• 2010

A new bis-Ru(II) complex, in which two [Ru(1,10-phenanthroline)$_2$dipyrido[3,2-a:2',3'-c]phenazine]$^{2+}$ were tethered by a 1,3-bis(4-pyridyl)propane linker, was synthesized and its binding mode and stoichiometry to DNA was investigated by optical spectroscopy including linear dichroism (LD) and fluorescence intensity measurement. The magnitude of the negatively reduced LD signal of the bis-Ru(II) complex in the dipyrido[3,2-a:2',3'-c]phenazine (DPPZ) ligand absorption region appeared to be similar compared to that in the DNA absorption region, which is considered to be a diagnostic for DPPZ ligand intercalation. The binding stoichiometry measured from its LD magnitude and enhanced fluorescence intensity corresponds to one ligand per three DNA bases, effectively violating the nearest neighbouring site exclusion model for classical DNA intercalation. This observation is in contrast with monomer analogue [Ru(1,10-phenanthroline)$_2$dipyrido[3,2-a:2',3'-c]phenazine]$^{2+}$, which is saturated at the DPPZ ligand to DNA base ratio of 0.25, or one DPPZ ligand per four nucleobases.

• Biomolecules & Therapeutics
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• v.29 no.5
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• pp.562-570
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• 2021

Topoisomerase IIα has been a representative anti-cancer target for decades thanks to its functional necessity in highly proliferative cancer cells. As type of topoisomerase IIα targeting drugs, topoisomerase II poisons are frequently in clinical usage. However, topoisomerase II poisons result in crucial consequences resulted from mechanistically induced DNA toxicity. For this reason, it is needed to develop catalytic inhibitors of topoisomerase IIα through the alternative mechanism of enzymatic regulation. As a catalytic inhibitor of topoisomerase IIα, AK-I-191 was previously reported for its enzyme inhibitory activity. In this study, we clarified the mechanism of AK-I-191 and conducted various types of spectroscopic and biological evaluations for deeper understanding of its mechanism of action. Conclusively, AK-I-191 represented potent topoisomerase IIα inhibitory activity through binding to minor groove of DNA double helix and showed synergistic effects with tamoxifen in antiproliferative activity.

• KIISE Transactions on Computing Practices
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• v.23 no.3
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• pp.171-176
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• 2017

Recently, several information-technology research projects such as those for high-performance computing, the cloud service, and the DevOps methodology have been advanced to develop the efficiency of satellite data-processing systems. In March 2019, the Geostationary Ocean Color Imager II (GOCI-II) will be launched for its predictive capability regarding marine disasters and the management of the fishery environment; moreover, the GOCI-II Ground Segment (G2GS) system for data acquisition/processing/storing/distribution is being designed at the Korea Ocean Satellite Center (KOSC). The G2GS is composed of the following six functional subsystems: data-acquisition subsystem (DAS), data-correction subsystem (DCS), precision-correction subsystem (PCS), ocean data-processing subsystem (ODPS), data-management subsystem (DMS), and operation and quality management subsystem (OQMS). The G2GS will enable the real-time support of the GOCI-II ocean-color data for government-related organizations and public users.

• The Korean Journal of Zoology
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• v.36 no.3
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• pp.367-372
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• 1993

We have found a protein kinase activity that is tightly associated with type II DNA topoisomerase purified from regenerating rat liver. The activities of protein kinase and topoisomerase II were not separable when the enzyme was subjected to analytical chromatographies (Hydroxyapatite, phosphocellulose, and double strand DNA cellulose) and glycerol gradient sedimentation. The kinase activity from purified rat topoisomerase II was also inactivated by the topoisomerase II inhibitors such as N-ethylmaleimide or novobiocin. The evidences, however, do not rule out a possibility that the kinase activity resides in a polypeptide other than the topoisomerase II protein. The topoisomerase II-associated protein kinase required Mg++ for its activity, and this requirement was not substituted by any other mono- or divalent ions. Histone H1 act as a strong stimulator and a good substrate for the kinase activity and other histones and ${\alpha}$-casein could not substitute the effect of histone H1.

• The Research Journal of the Costume Culture
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• v.18 no.5
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• pp.923-941
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• 2010

The purpose of this study examines women in 20s~30s who start applying adult makeup and are sensitive to cosmetics and makeup techniques to understand the influence of overseas cosmetic brands' personality on their preference to provide overseas cosmetic brands with unique personality marketing resources. The following summarize the findings of this study: first, overseas cosmetic brands' personality factors were aesthetics, performance, interest, competency, and boldness. Second, among imported brands, the most preferred brand was Christian Dior, followed by Bobbi Brown, Chanel, SK-II, and Estee Lauder. Third, the subjects preferred Chanel when they perceived its aesthetics, performance, and competency and Christian Dior when they perceived its aesthetics and performance and did not perceive its boldness as much. They preferred Estee Lauder when they perceived its aesthetics and competency and Bobbi Brown when they perceived its aesthetics, performance, and competency and did not perceive its boldness as much. In case of SK-II, they preferred it when they perceived its aesthetics, performance, interest, and competency.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.487-490
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• 2004

In this paper, we investigated the characteristics of initiation and propagation behavior for fatigue crack observed by changing various shapes of initial crack and magnitudes of loading in modified compact tension shear(CTS) specimen subjected to shear loading. In the low-loading condition, the secondary fatigue crack was created in the notch root due to friction on the pre-crack face grew to a main crack. In the high-loading condition, fatigue crack under shear loading propagated branching from the pre-crack tip. Influenced by the shear loading condition, fatigue crack propagation retardation appeared in the initial propagation region due to the reduction of crack driving force and friction on crack face. In both cases, however, fatigue cracks grew in tensile mode type. The propagation path of fatigue crack under the Mode II loading was 70 degree angle from the initial crack regardless of its shape and load magnitude.