• Toxicological Research
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• 제14권3호
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• pp.371-377
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• 1998

We have cloned a soluble type human folate receptor(hFR type${\gamma}$) from human thymus cDNA library using the PCR amplification technique. To examine whether hFR type${\gamma}$ has a folate transport activity, CHO cells were transfected with the pcDNAhFR${\gamma}$ expression plasmid, and the stable cell line CHO/hFR${\gamma}$ expressing a high level of the hFR type${\gamma}$ was identified by northern and western blot analysis. The CHO/hFR${\gamma}$ cells produced a [$H^3$]folic acid binding protein in the culture medium. However, we couldn't detect any cell surface [$H^3$] folic acid binding and transport activities. The growth of the CHO/hFR${\gamma}$ cells was more rapidly inhibited than the wild type CHO cells in the low concentration folic acid media. These observations indicate that although soluble type human folate receptor can bind [$H^3$]folate, it does not involve in folate transport.

• Preventive Nutrition and Food Science
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• 제4권3호
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• pp.175-179
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• 1999

To develop a production method for modified starches with less pollution, pH adjustment and gamma irradiation were applied to commerical corn starch. Blue values were significantly decreased , while alkali number, optical transmittance and solubility markedly increased when gamma irradiation was applied to pH 2 adjusted corn starch. Water binding capacity and swelling power at pH 5 were the highest among the samples. Gelatinization viscosity was considerably affected by gamma irradiation and pH of the starch. Gamma irradiation of pH 2 adjusted starch showed the lowest peak viscosity and the best cooling stability among the tested samples . Therefore, the production of modified starch with low viscosity as well as with sufficient viscosity stability seems feasible by controlling the pH of the starch and gamma irrdiation.

• Korean Chemical Engineering Research
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• 제46권3호
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• pp.545-549
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• 2008

${\gamma}-AlO$(OH) 졸 입자 뿐만 아니라 소성처리된 ${\gamma}-Al_2O_3$ 입자의 표면특성을 ${\gamma}-AlO$(OH) 졸 제조시 숙성단계에 의하여 조절하였다. 연구결과, ${\gamma}-AlO$(OH) 졸 입자의 등전점은 숙성 증가에 따라 pH 9.25에서 pH 8.70까지 감소하였으며 ${\gamma}-Al_2O_3$ 입자의 경우는 pH 9.90에서 pH 8.86까지 감소하였다. 숙성에 따른 ${\gamma}-Al_2O_3$ 입자의 산, 염기 특성을 고찰한 결과, ${\gamma}-Al_2O_3$ 입자의 산량은 숙성시간의 증가에 따라 0.1367 mmol/g에서 0.0783 mmol/g까지 감소하였으며, Hammett 산성도함수 $H_o$는 4.8 이상의 산세기를 보였다. 한편 ${\gamma}-Al_2O_3$ 입자의 염기량은 숙성시간의 증가에 따라 0.4399 mmol/g에서 0.3074 mmol/g 까지 감소하였다. 따라서 졸-겔법에 의한 ${\gamma}-Al_2O_3$ 제조시 숙성공정이 산, 염기점의 양을 포함한 표면특성을 조절할 수 있는 중요 공정변수임을 제시하였다.

• Parasites, Hosts and Diseases
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• 제32권3호
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• pp.185-194
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• 1994

T. gonnii의 Beverley주를 감염시킨 마우스(감염군)로부터 분리한 복강대식세포에 cytokine의 종류 및 농도에 따른 대식세포의 활성화 정도를 평가하기 위하여 복강대식세포 단세포층에 medium, 조제 Iymphokine, 재조합 tumornecrosis $factor-{\alpha}{\;}(TNF-{\alpha})$. 재조합 $interferon-{\gamma}{\;}(IFN-{\gamma})$, 및 재조합 $IFN-{\gamma}와{\;}TNF-{\alpha}$를 함께($IFN-{\gamma}/TNF-{\alpha}$) 처치한 후, 각 처치군별 $H_2O_2{\;}생산량,{\;}NO2^{-}$ 생산량 및 T. gondii의 대식세포내 침투억제능을 측정하였다. 감염군의 복강대식세포에 $IFN-{\gamma}{\;}처치시{\;}NO2^{-}$ 생산량은 농도에 따라 유의하게 증가하였으나 그외의 처치군에서는 농도에 따른 유의한 차이가 없었다. 감염군 대식세포에 $IFN-{\gamma}나{\;}IFN-{\gamma}/TNF-{\alpha}$ 처치시 $H_2O_2$ 생산량이 medium처치군보다 유의하게 증가하였으며. $NO2^{-}$ 생산량은 $TNF-{\alpha},{\;}IFN-{\gamma}나{\;}IFN-{\gamma}/TNF-{\alpha}$ 처치시 유의하게 증가하였다. 감염군에 cytokine 처치시 T. gondii의 대식세포내 침투억제능은 medium 처치시보다 모두 증가되었다 또한 정상군과 감염군의 $H_2O_2$ 생산량, $NO2^{-}$ 생산량 및 T. gondii의 대식세포내 침투억제능을 상호 비교시 $IFN-{\gamma}$ 처치군은 유의한 차이를 나타냈으나 그 외의 cytokine 처치군에서는 유의한 차이를 나타내지 않았다. 이상의 성적으로 보아 $IFN-{\gamma}$가 Toxoplosma감염 마우스 복강대식세포의 활성화에도 중요한 역할을 함을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1475-1479
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• 2012

Human peroxisome proliferator-activated receptor gamma ($hPPAR{\gamma}$) has been implicated in numerous pathologies, including obesity, diabetes, and cancer. In this study, we verified that amentoflavone is an agonist of $hPPAR{\gamma}$ and probed the molecular basis of its action. It was demonstrated that amentoflavone bound $hPPAR{\gamma}$ with high (picomolar) affinity and increased the binding between $hPPAR{\gamma}$ and steroid receptor coactivator-1 (SRC-1) by approximately 4-fold. Based on a docking study, for the first time, we propose a model of amentoflavone and $hPPAR{\gamma}$ binding in which amentoflavone forms three hydrogen bonds with the side chains of His323, Tyr327, and Arg280 in $hPPAR{\gamma}$ and participates in two hydrophobic interactions.

• 한국초전도ㆍ저온공학회논문지
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• 제16권4호
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• pp.26-30
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• 2014

We investigate the upper critical field anisotropy ${\Gamma}_H$ and the magnetic penetration depth anisotropy ${\Gamma}_{\lambda}$ of a high-quality $FeSe_{1-x}$ single crystal using angular dependent resistivity and torque magnetometry up to 14 T. High quality single crystals of $FeSe_{1-x}$ were successfully grown using $KCl-AlCl_3$ flux method, which shows a sharp superconducting transition at $T_C{\sim}9K$ and a high residual resistivity ratio of ~ 25. We found that the anisotropy ${\Gamma}_H$ near $T_C$ is a factor of two larger than found in the poor-quality crystals, indicating anisotropic 3D superconductivity of $FeSe_{1-x}$. Similar to the 1111-type Fe pnictides, the anisotropies ${\Gamma}_{\lambda}$ and ${\Gamma}_H$ show distinct temperature dependence; ${\Gamma}_H$ decreases but ${\Gamma}_{\lambda}$ increases with lowering temperature. These behaviors can be attributed to multi-band superconductivity, but different from the case of $MgB_2$. Our findings suggest that the opposite temperature dependence of ${\Gamma}_{\lambda}$ and ${\Gamma}_H$ is the common properties of Fe-based superconductors.

• Nuclear Engineering and Technology
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• 제51권1호
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• pp.263-268
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• 2019

The $^3He$ proportional chamber is widely used for neutron measurement owing to its high neutron detection efficiency and simplicity for gamma-ray rejection. In general, the neutron and gamma-ray signals obtained from the $^3He$ proportional chamber can be easily separated by the difference in the pulse heights. However, for a high gamma-ray field, the gamma-ray signal cannot be precisely eliminated by the pulse height due to gamma-ray pulse pileup which causes the pulse height of gamma-ray pulse to increase and making the pulses due to neutrons and gamma rays indistinguishable. In this study, an improved algorithm for $n/{\gamma}$ discrimination using a parameter, which is the ratio of the rise time to the pulse height, is proposed. The $n/{\gamma}$ discrimination performance of the algorithm is evaluated by applying it to $^{252}Cf$ neutron signal separation from various gamma-ray exposure rate levels ranging 0.1-5 R/h. The performance is compared to that of the conventional pulse-height analysis method in terms of the gamma elimination ratio. The suggested algorithm shows better performance than the conventional one by 1.7% (at 0.1 R/h) to 70% (at 5 R/h) for gamma elimination.

• 대한수학회보
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• 제34권4호
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• pp.627-636
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• 1997

Let $H(U)$ be the space of all analytic functions in the unit disk $U$ and let $K \subset H(U)$. For the operator $A_{\beta,\gamma} : K \longrightarrow H(U)$ defined by $$ A_{\beta,\gamma}(f)(z) = [\frac{z^\gamma}{\beta + \gamma} \int_{0}^{z} f^\beta (t)t^{\gamma-1} dt]^{1/\beta} $$ and $\beta,\gamma \in C$, we determined conditions on g(z), $\beta and \gamma$ such that $$ z[\frac{z}{f(z)]^\beta \prec z[\frac{z}{g(z)]^\beta implies z[\frac{z}{A_{\beta,\gamma}(f)(z)]^\beta \prec z[\frac{z}{A_{\beta,\gamma}(g)(z)]^\beta $$ and we presented some particular cases of our main result.

• Biomolecules & Therapeutics
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• 제18권1호
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• pp.16-23
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• 2010

Adipocyte differentiation in human bone marrow mesenchymal stem cells (hBM-MSCs) is not as efficient as that in murine pre-adipocytes when induced by adipogenic agents including insulin, dexamethasone, and 3-isobutyl-1-methylxanthine (IDX condition). Therefore, the promotion of adipocyte differentiation in hBM-MSCs has been used as a cell culture model to evaluate insulin sensitivity for anti-diabetic drugs. In hBM-MSCs, $PPAR{\gamma}$ agonists or sulfonylurea anti-diabetic drugs have been added to IDX conditions to promote adipocyte differentiation. Here we show that troglitazone, a peroxisome proliferator-activated receptor-gamma ($PPAR{\gamma}$) agonist, significantly reduced the levels of anti-adipogenic $PGE_2$ in IDX-conditioned hBM-MSC culture supernatants when compared to $PGE_2$ levels in the absence of $PPAR{\gamma}$ agonist. However, there was no difference in the mRNA levels of cyclooxygenases (COXs) and the activities of COXs and prostaglandin synthases during adipocyte differentiation in hBM-MSCs with or without troglitazone. In hBM-MSCs, troglitazone significantly increased the mRNA level of 15-hydroxyprostaglandin dehydrogenase (HPGD) which can act to decrease $PGE_2$ levels in culture. These results suggest that the role of $PPAR{\gamma}$ activation in promoting adipocyte differentiation in hBM-MSCs is to reduce anti-adipogenic $PGE_2$ levels through the up-regulation of HPGD expression.

• Asian-Australasian Journal of Animal Sciences
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• 제26권10호
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• pp.1399-1405
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• 2013

The present study focused on establishing the effects of interferon-gamma (IFN-${\gamma}$) on interleukin-18 (IL-18) expression patterns and pregnancy outcomes in pregnant rats. Pregnant rats at the post-implantation stage were randomized into control, low IFN-${\gamma}$ (L-IFN-${\gamma}$) and high IFN-${\gamma}$ groups (H-IFN-${\gamma}$) that received normal saline, 100 IU/g of IFN-${\gamma}$ and 500 IU/g of IFN-${\gamma}$ vaginal muscular injection, respectively. The effects of IFN-${\gamma}$ on IL-18 expression and pregnancy outcomes were assessed systematically using several methods, including immunohistochemistry streptavidin-perosidase (SP), image pattern analysis, enzyme-linked immune-sorbent assay (ELISA), whole blood count (WBC) count, microscopy and visual observation. IL-18 was detected in the uteri of all pregnant rats, and mainly distributed in the endometrium, decidual cells, vascular endothelium and myometrium. Immunohistochemistry and image pattern analyses revealed significantly lower IL-18 expression in the H-IFN-${\gamma}$ group compared to the L-IFN-${\gamma}$ and control groups (p<0.01), indicating that high doses of IFN-${\gamma}$ induce downregulation of IL-18 in the uterus of pregnant rats. ELISA results disclosed that IL-18 expression in peripheral blood of the H-IFN-${\gamma}$ group was lower than that of the L-IFN-${\gamma}$ group (p<0.05), and significantly reduced compared to the control group (p<0.01). Moreover, the number of peripheral leukocytes in the H-IFN-${\gamma}$ group was significantly higher than those in the control and L-IFN-${\gamma}$ groups (p<0.01). Morphology analysis showed no evident differences between the L-IFN-${\gamma}$ and control groups. However, for the H-IFN-${\gamma}$ group, uterine mucosa bleeding, necrosis and excoriation were observed using microscopy. Visual observation revealed marroon, swelling, crassitude and no embryo in the uterus, which are obvious indicators of abortion. These results indicate that IFN-${\gamma}$ plays a regulatory role in IL-18 expression in the uterus and peripheral blood of pregnant rats at the post-implantation stage. Moreover, high levels (500 IU/g) of IFN-${\gamma}$ influence normal pregnancy at the early stages in rats by downregulating IL-18 expression in the uterus and peripheral blood and increasing the number of peripheral leukocytes, consequently triggering termination of pregnancy.