• Journal of the Korean Chemical Society
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• v.61 no.1
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• pp.29-33
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• 2017

Formation of Au particles in nonstoichiometric $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$) oxide from aniline + hydrochloric acid mixtures and chloroauric acid in the ratios 30 : 1; 60 : 1; 90 : 1 (S1-S3) by volume and 0.01 mol of copper acetate, $Cu(OCOCH_3)_2.H_2O$, in each case is performed by sol-gel growth. Powder x-ray diffraction (XRD) results show Au particles are dispersed in tetragonal nonstoichiometric dicopper (I) dicopper (II) oxides, $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$). Average crystallite sizes of Au particles determined using Scherrer equation are found to be in the approximate ranges ${\sim}85-140{\AA}$, ${\sim}85-150{\AA}$ and ${\sim}80-150{\AA}$ in S1-S3, respectively which indicate the formation of Au nano-micro size particles in $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$) oxides. Hysteresis behaviour at 300 K having low loop areas and magnetic susceptibility values ${\sim}5.835{\times}10^{-6}-9.889{\times}10^{-6}emu/gG$ in S1-S3 show weakly ferromagnetic nature of the samples. Broad and isotropic electron paramagnetic resonance (EPR) lineshapes of S1-S4 at 300, 77 and 8 K having $g_{iso}$-values ${\sim}2.053{\pm}0.008-2.304{\pm}0.008$ show rapid spin-lattice relaxation process in magnetic $Cu^{2+}$ ($3d^9$) sites as well as delocalized electrons in Au ($6s^1$) nano-micro size particles in the $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$) oxides. Broad and weak UV-Vis diffuse reflectance optical absorption band ~725 nm is assigned to $^2B_{1g}{\rightarrow}^2A_{1g}$ transitions, and the weak band ~470 nm is due to $^2B_{1g}{\rightarrow}^2E_g$ transitions from the ground state $^2B_{1g}$(${\mid}d_{x^2-y^2}$>) of $Cu^{2+}$ ($3d^9$) ions in octahedral coordination having tetragonal distortion.

• Biomedical Science Letters
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• v.3 no.2
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• pp.125-130
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• 1997

Taxol, an anticancer drug that has diterpenoid conformation, has been used as an effective chemotherapeutical agent in the treatment of breast and ovarian cancers. Because of its toxicity like other anticancer drugs, monitoring the taxol level in serum is important procedure during cancer therapy. The various monitoring methods using HPLC, ELISA, and RIA have been adopted, and RIA technique is known to be superior than other methods in trems of sensitivity and convenience. In this study, in order to develope taxol RIA system using $^{125}$I labelled antigen, first of all we synthesized taxol derivatives. 2'-hemisuccinyltaxol was obtained with about 80％ yield by esterification of taxol at C-2' hydroxyl group on C-13 carbon with succinic anhydride. [$^{125}$I]iodotyramine was prepared with 58％ labelling yield by radioiodination of tyramine and purified by gel chromatography. 2'-[$^{125}$I]iodotyramine-hemisuninyltaxol, $^{125}$I labelled antigen for taxol RIA, was synthesized with 96% yield from conjugation of 2'-hemisuccinyltaxol and [$^{125}$I]iodotyramine. Anti-taxol serum was produced from the rabbit immunized with 2'-hemisuccinyltaxol-BSA synthesized by 2'-hemisuccinyltaxol and BSA. The antiserum titer was determined by RIA using 2'-[$^{125}$I]iodotyramine-hemisuccinyltaxol. The titer of 1:20 was obtained with about 40% of B/T. The results suggest that taxol RIA using $^{125}$I labelled antigen can be applied to monitor the taxol level in serum.

• Korean Journal of Agricultural Science
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• v.25 no.1
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• pp.68-78
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• 1998

To investigate the genetic polymorphisms and constitutions of blood proteins and enzymes in the Korean native cattle population of National Livestock Cooperatives Federation(NLCF), the genetic variants of transferrin(Tf), post-transferrin-2(pTf-2), albumin(Alb), post-albumin(pAlb), ceruloplasmin(Cp), amylase-I(Am-I) and herroglobin(Hb) were analyzed using the PAGE(polyacrylamide gel electrophoresis) and ST AGE(starch gel electrophoresis) methods. On the genetic variants of the serum proteins, the transferrin(Tf) locus was assumed to be genetically controlled by codominant alleles, Tf A, $D_1$, $D_2$ and E alleles, and the gene frequencies of these were 0.249, 0.248, 0.260 and 0.243, respectively. The post-transferrin locus was observed to be controlled by pTf-2 F and S alleles, and the gene frequencies of these were 0.662 and 0.338, respectively. The post-albumin(pAlb) loci were identified to be controlled by two alleles, pAlb F and S alleles for pAlb locus, and the gene frequncies of these were 0.440 and 0.560 for pAlb F and S alleles, respectively. On the genetic variants of the serum enzymes, ceruloplasmin(Cp) and amylase-I(Am-I) loci were found to be controlled by two alleles, Cp F and S for Cp locus, and Am-I B and C for Am-I locus, and gene frequencies of these were 0.319 and 0.681 for Cp F and S, and 0.871 and 0.120 for Am-I Band C, respectively. On the genetic variants of the hemoglobin(Hb), the distributions of genotypes were 76.5, 21.2 and 2.3% for Hb AA, AB and BB types, and the gene frequnecies for Hb A and B were 0.871 and 0.129, respectively. On the effects of genetic variants of blood proteins, Tf $D_1D_1$, $D_2D_2$ and $D_2E$ genotypes were significantly higher on body weight at 6 month and average daily gain than that of other Tf genotypes.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.2
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• pp.301-321
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• 2019

The development of a rapidly hardening seal material applicable to steel pipe multistage grouting is described in this paper. In the multistage technique, seal materials are inserted to prevent the backflow of main grouting material. The grouting material must be inserted only after sufficient time has passed for the seal material to reach a gel state. Otherwise, the fluid seal material mixes with the main grouting material and a backflow of the grouting material occurs, thereby making its in situ insertion difficult. Furthermore, if the seal material remains in the gel state for too long a time, it solidifies; and the main grouting material will not be able to seep into the soil. The gel time, i.e., the time needed for the fluid seal material to turn into a gel state, determines the construction period of steel pipe multistage grouting. The gel time is one of the important factors in this technique, because it impacts the total tunnel construction period significantly. This study develops a rapidly hardening calcium aluminate material, which can reduce the gel time and shorten the construction period while retaining proper sealing function. It also presents a method to determine whether the seal material has reached the gel state as well as the quality standard and bleeding rate testing method for the seal material in the gel state.

• Korean Journal of Microbiology
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• v.40 no.3
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• pp.199-204
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• 2004

The parathion hydrolase (OPH) produced by Pseudomonas rhodesiae H5 was purified by ammonium sulfate precipitation, DEAE-Toyopearl 650M ion exchange chromatography and Sephadex gel filtration chromatography. Parathion hydrolase from crude extracts of P. rhodesiae H5 has two components designated as OPH $I_1$ and OPH $I_2$, Optimum pH and temperature of OPH $I_1$and OPH $I_2$ were pH 7.2 and $30^{\circ}C$, and pH 7.6 and $37^{\circ}C$, respectively. The activation energy of OPH $I_1$ for the hydrolysis of parathion was 3.01 ㎉/I, II, III in the temperature range of $4^{\circ}C$ to $30^{\circ}C$, and Michaelis constant ($K_m$) for parathion was 69.2 ${\mu}M$. The activation energy of OPH $I_2$ for the hydrolysis of parathion was 4.07㎉/㏖ in the temperature range of $4^{\circ}C$ to $37^{\circ}C$, and Michaelis constant for parathion was 150.9${\mu}M$. Furthermore OPH $I_1$ was completely inhibited by 1 mM $Ca^2+$, $Cu^2+$, $Mg^2+$, $Ni^2+$, but OPH $I_2$ was less inhibited than OPH $I_1$ by the metals used in this study.

• BMB Reports
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• v.40 no.5
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• pp.825-831
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• 2007

Tumor cell invasion and metastasis are often associated with matrix metalloproteinases (MMPs), among which MMP-2 and MMP-9 are of central importance. We previously showed that H-Ras, but not N-Ras, induced invasion of MCF10A human breast epithelial cells in which the enhanced expression of MMP-2 was involved. MMP-2 is produced as a latent pro-MMP-2 (72 kDa) to be activated resulting the 62 kDa active MMP-2. The present study investigated if H-Ras and/or N-Ras induces pro-MMP-2 activation of MCF10A cells when cultured in two-dimensional gel of type I collagen. Type I collagen induced activation of pro-MMP-2 only in H-Ras MCF10A cells but not in N-Ras MCF10A cells. Induction of active MMP-2 by type I collagen was suppressed by blocking integrin ${\alpha}2$, indicating the involvement of integrin signaling in pro-MMP-2 activation. Membrane-type (MT)1-MMP and tissue inhibitor of metalloproteinase (TIMP)-2 were up-regulated by H-Ras but not by N-Ras in the type I collagen-coated gel, suggesting that H-Ras-specific up-regulation of MT1-MMP and TIMP-2 may lead to the activation of pro-MMP-2. Since acquisition of pro-MMP-2 activation can be associated with increased malignant progression, these results may help understanding the mechanisms for the cell surface matrix-degrading potential which will be crucial to the prognosis and therapy of breast cancer metastasis.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.318-323
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• 1995

The effect of AF-toxin I produced by the strawberry pathotype of Alternaria alternata on the protein synthesis of susceptible strawberry protoplasts was examined by using the radiolabeled amino acids. The incorporation of the radiolabeled amino acids into newly synthesized proteins in the strawberry protoplasts was stimulated by the toxin treatment at relatively low concentrations (2.2$\times$10-11 to 2.2$\times$10-9 M), but not at higher concentrations (2.2$\times$10-8 to 2.2$\times$10-6 M). An one-dimensional SDS-polyacrylamide gel electrophoresis revealed no detectable differences in the proteins synthesized in both the toxintreated and untreated protoplasts. The susceptible strawberry protoplasts were treated with AF-toxin I and stained with Fluostain I to detect the extracellular polysaccharides. The toxin treatment induced the accumulation of extracellular polysccharides in a dose-dependent manner. These results indicate a transient activation of cellular metabolism in the susceptible cells by the toxin exposure.

• YAKHAK HOEJI
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• v.21 no.2
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• pp.110-114
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• 1977

The purified .omicron.-iodobenzoic acid-$^{131}$ I, sodium iodide-$^{131}$I and mixtures of those compounds were applied to radio paper or radio thin layer chromatography to select the developing solvents with useful separation efficiency. The separation efficiencies were checked by radiochromatogram sacnnings. It has been found that the two dimensional radio paper chromatogrphy using the solvent systems of 8% phenol and butanol-glacial acid-water (4:1:1 v/v) and the radio thin layer chromatography using alumina gel plate and butanol- glacial acetic acid- water (4:1:1 v/v) are both efficient. In this method, the Rf value of .omicron.-iodobenzoic acid-$^{131}$ I and the unbound $^{131}$ I is 0.48, 0.85 and 0.15, respectively.

• Journal of the Korean Ceramic Society
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• v.27 no.5
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• pp.625-630
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• 1990

Cordierite powders were prepared from Si(OC2H5)4, Al(OC3H7i)3 and Mg(OC2H5)2 by the sol-gel method. Two different methods were applied for producing fine and homogeneous powders. One is that Si(OC2H5)4 with a lowr rate of hydrolysis was partially hydrolyzed and then Al(OC3H7i)3 and Mg(OC2H5)2 were mixed and reacted. The other is based on the simultaneous hydrolysis of these metal alkoxides using i-C4H9OH which retards the rate of hydrolysis of Al(OC3H7i)3 and Mg(OC2H5)2. It was confirmed that ifne and homogeneous powders were obtained from both methods. Also these powders were calcined at four different temperatures during two hours. X-ray diffraction patterns show only ${\mu}$-cordierite phase at 1000$^{\circ}C$, ${\mu}$-cordierite and ${\alpha}$-cordierite phases at 1100-1200$^{\circ}C$ and ${\alpha}$-cordierite phase at 1300$^{\circ}C$ respectively.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.10a
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• pp.139-140
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• 1997

1. 서론 : 한외 및 정밀여과의 분리메카니즘에 연관된 물리적 현상에 대해 현재까지 진행된 많은 연구들은, 막기공이 갖는 복잡하고 불규칙한 구조를 단순하고 규칙적인 well-defined 구조인 실린더형이나 슬릿형 기공으로 가정하여 문제를 전개하고 있다. 본래, 다공성 매질(porous media)에서의 유체흐름을 다루는 이론 및 실험연구자들에 의해 제안된 섬유상 매질(fibrous media)에 대한 해석은 계의 미세구조(microstructure)에 추계적 개념을 적용시키려는 최근의 추세에 따라 점차 관심이 높아가고 있다.(생략)