• Title/Summary/Keyword: Y2k

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Cyclooxygenase-2 as a Molecular Target for Cancer Chemopreventive Agents

  • Surh, Young-Joon
    • Toxicological Research
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    • v.17
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    • pp.89-96
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    • 2001
  • Recently, considerable attention has been focused on the role of cyclooxygenase-2 (COX-2) in the carcinogenesis as well as in inflammation. Improperly overexpressed COX-2 has been observed in many types of human cancers and transformed cells in culture. Thus, it is conceivable that targeted inhibition of abnormally or improperly up-regulated COX-2 provides one of the most effective and promising strategies for cancer prevention. A ubiquitous eukaryotic transcription factor, NF-kB is considered to be involved in regulation of COX-2 expression. Furthermore, extracellular-regulated protein kinase and p38 mitogen-activated protein (MAP) kinase appear to be key elements of the intracellular signaling cascades involved in NF-kB activation in response to a wide array of external stimuli. Certain chemopreventive phytochemicals suppress activation of NF-kB by blocking one or more of the MAP kinases, which may contribute to their inhibitory effects on COX-2 induction. One of the plausible mechanisms by which chemopreventive phytochemicals inhibit NF-kB activation involves suppression of degradation of the inhibitory unit I kB, which hampers subsequent translocation of p65, the functionally active subunit of NF-kB.

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INTEGER POINTS ON THE ELLIPTIC CURVES INDUCED BY DIOPHANTINE TRIPLES

  • Park, Jinseo
    • Communications of the Korean Mathematical Society
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    • v.35 no.3
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    • pp.745-757
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    • 2020
  • A set {a1, a2, …, am} of positive integers is called a Diophantine m-tuple if aiaj + 1 is a perfect square for all 1 ≤ i < j ≤ m. In this paper, we find the structure of a torsion group of elliptic curves Ek constructed by a Diophantine triple {F2k, F2k+2, 4F2k+1F2k+2F2k+3}, and find all integer points on the elliptic curve under assumption that rank(Ek(ℚ)) = 2.

Effect of Zibachunggan-tang on lipopolysaccharide-induced expression of NF-kB downstream genes in HepG2 cell (자발 '청간탕'이 HepG2 cell의 염증반응에 대한 연구)

  • Hong Sang Hoon;Choi Byung Tae;Lee Yong Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.5
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    • pp.1251-1256
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    • 2003
  • To determine the effect of Zibachunggan-tang(ZCT) on the process of lipopolysaccharide (LPS)-induced nuclear factor-kBp65 (NF-kBp65) activation, and LPS-induced expression of pro-inflammatory proteins including tumor necrosis factor-α (TNF-α), nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in HepG2 cell. Immunoblot analysis showed that the level of nucleic NF-kBp65 was rapidly up-regulated and cytosolic inhibitory I-kBα was down-regulated by LPS challenge. While ZCT inhibited an increase of NF-kBp65 and degradation of I-kBα in HepG2 cell. Beside LPS-induced expression of a group of genes, such as TNF-α, inducible iNOS and COX-2, are repressed by ZCT. It may be concluded that ZCT attenuates the progress of LPS-induced inflammation by reduction of NF-kBp65 activation. The ZCT would be useful as a therapeutic agent for endotoxin-induced liver disease.

Synthesis of 5-methylbicyclo[2.2.1]hept-2-ene-5-carboxylates (5-Methylbicyclo[2.2.1]hept-2-ene-5-carboxylates의 합성)

  • Lee, Yoon-Bae;Jun, Joon-Ho;Sung, Un-Gyung;Ma, Dong-Hwan
    • Proceedings of the KAIS Fall Conference
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    • 2008.11a
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    • pp.339-342
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    • 2008
  • Methacrylate와 Cyclopentadiene을 반응하여 5-methylbicyclo[2.2.1]hept-2-ene-5-carboxylate (MBHC)를 합성하고 만들어진 MBHC를 Column Chromatography를 이용하여 Endo와 Exo를 분리하였고, MBHC에 붙는 작용기에 따른 수율 및 Endo, Exo의 비율을 확인하였다.

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Structure and Magnetic Properties of Cr2O3/CrO2 Nanoparticles Prepared by Reactive Laser Ablation and Oxidation under High Pressure of Oxygen

  • Si, P.Z.;Wang, X.L.;Xiao, X.F.;Chen, H.J.;Liu, X.Y.;Jiang, L.;Liu, J.J.;Jiao, Z.W.;Ge, H.L.
    • Journal of Magnetics
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    • v.20 no.3
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    • pp.211-214
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    • 2015
  • $Cr_2O_3$ nanoparticles were prepared via one-step reactive laser ablation of Cr in oxygen. The metastable $CrO_2$ phase was obtained through the subsequent oxidation of $Cr_2O_3$ nanoparticles under $O_2$ with gas pressures of up to 40 MPa. The as-prepared $Cr_2O_3$ nanoparticles are spherical or rectangular in shape with sizes ranging from 20 nm to 50 nm. High oxygen pressure annealing is effective in producing meta-stable $CrO_2$ from as-dried $Cr_2O_3$ nanoparticles, and the $Cr_2O_3$ nanoparticles exhibit a weak ferromagnetic behavior with an exchange bias of up to 11 mT that can be ascribed to the interfacial exchange coupling between uncompensated surface spins and the antiferromagnetic core. The $Cr_2O_3/CrO_2$ nanoparticles exhibit an enhanced saturation magnetization and a reduced exchange bias with an increasing faction of $CrO_2$ due to the elimination of uncompensated surface spins over the $Cr_2O_3$ nanoparticles when exposed to a high pressure of $O_2$ and/or possible phase segregation that results in a smaller grain size for both $Cr_2O_3$ and $CrO_2$.

YBCO coated conductor with a single buffer layer of Yttrium Oxide

  • Park, Chan;Dongqi Shi;Kyujeong Song;Rokkil Ko;Park, Soojeong;Yoo, Sang-Im
    • Progress in Superconductivity and Cryogenics
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    • v.5 no.3
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    • pp.20-22
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    • 2003
  • Y$_2$O$_3$ films were pulsed laser deposited on cube textured Ni and Ni-W substrates to be used as a single buffer layer of YBCO coated conductor. Initial deposition of $Y_2$O$_3$ films was performed in a reducing atmosphere, and subsequent deposition was done in the base pressure of the chamber and oxygen atmosphere. The $Y_2$O$_3$ films have a strong cube texture (The full width at half maximum of the ø-scan of $Y_2$O$_3$ was 8.4 which was the same as that of metal substrate) and smooth crack-free microstructure. The biaxially textured YBCO films (The full width at half maximum of the ø-scan was 10.2) pulsed laser deposited on the $Y_2$O$_3$/metal exhibited Tc(R=0) of 86.5K and Jc of 0.7 MA/cm2 at 77K in self field, representing that the $Y_2$O$_3$ single buffer layer is an efficient diffusion barrier of Ni and thus very promising for the achievement of high-Jc YBCO coated conductor.

Assess of Breakdown Characteristics about Dry-Air & $N_2/O_2$ Mixture (Dry-Air 및 혼합가스의 절연성 평가)

  • Choi, Eun-Hyeok;Choi, Young-Kil;Jang, Seung-Ho;Choi, Sang-Tae;Woo, Sung-Hun;Kim, Lee-Kuk;Lee, Kwang-Sik
    • Proceedings of the KIEE Conference
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    • 2008.05a
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    • pp.127-128
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    • 2008
  • 현재 산업사회의 발달과 더불어 신뢰성 높은 양질의 전기에너지와 운전 및 보수의 간편화, 계통운용의 신뢰성의 확보가 요구되고 있다. 또한 $SF_6$을 대체할 친환경적인 절연매체의 개발이 절실히 요구되고 있다. 이에 본 연구는 모의 GIS내 친환경적인 절연재료인 질소($N_2$)와 산소($O_2$)의 혼합가스($N_2:O_2=79:21$, $N_2:O_2=60:40$, $N_2:O_2=40:60$)과 Dry-Air 기본적인 절연 특성을 밝혀, 각종 전력응용 설비의 절연매체로 사용가능함을 구명하고저 한다.

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Synthesis and herbicidal activities of 2-[4-(6-chloro-2-benzoxazolyloxy)-phenoxy]propionamide derivatives (2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy]-propionamide 유도체의 합성과 제초 활성)

  • Chang, Hae-Sung;Chung, Kun-Hoe;Ko, Young-Kwan;Ryu, Jae-Wook;Woo, Jae-Chun;Koo, Dong-Wan;Kang, Yong-Hee;Kim, Tae-Joon;Kim, Jin-Seog;Chung, Bong-Jin;Kwon, Oh-Yeon;Kim, Dae-Whang
    • The Korean Journal of Pesticide Science
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    • v.8 no.2
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    • pp.145-149
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    • 2004
  • A series of 2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy]-propionamide were synthesized and evaluated for post herbicidal activity under upland condition. 2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy]-N-(2-fluorophenyl)-N methyl propionamide showed high herbicidal activity against barnyardgrass with good selectivity on rice.

Suppression of Transglutaminase-2 is Involved in Anti-Inflammatory Actions of Glucosamine in 12-O-Tetradecanoylphorbol-13-Acetate-Induced Skin Inflammation

  • Park, Mi-Kyung;Cho, Sun-A;Lee, Hye-Ja;Lee, Eun-Ji;Kang, June-Hee;Kim, You-Lee;Kim, Hyun-Ji;Oh, Seung-Hyun;Choi, Chang-Sun;Lee, Ho;Kim, Soo-Youl;Lee, Chang-Hoon
    • Biomolecules & Therapeutics
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    • v.20 no.4
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    • pp.380-385
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    • 2012
  • Glucosamine (GS) is well known for the treatment of inflammation. However, the mechanism and efficacy of GS for skin inflammation are unclear. The aim of this study was to evaluate the effects and mechanism of GS in the mouse 12-O-tetradecanoyl 13-acetate (TPA)-induced ear edema model. TPA-induced ear edema was evoked in ICR or transglutaminase 2 (Tgase-2) (-/-) mice. GS was administered orally (10-100 mg/kg) or topically (0.5-2.0 w/v %) prior to TPA treatment. Orally administered GS at 10 mg/kg showed a 76 or 57% reduction in ear weight or myeloperoxidase, respectively, and a decreased expression of cyclooxygenase-2 (COX-2), NF-${\kappa}B$ and Tgase-2 in TPA-induced ear edema by western blot and immunohistochemistry. Role of Tgase-2 in TPA ear edema is examined using Tgase-2 (-/-) mice and TPA did not induce COX-2 expression in ear of Tgase-2 (-/-) mice. These observations suggested that Tgase-2 is involved in TPA-induced COX-2 expression in the inflamed ear of mice and antiinflammatory effects of glucosamine is mediated through suppression of Tgase-2 in TPA ear edema.