• Title, Summary, Keyword: EC-Mechanism

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A Construction of an Ontology Server and a Personalized Product Search Mechanism for Intelligent EC (지능형 전자상거래를 위한 온토로지 서버 구축과 개인 적응형 상품검색)

  • Chung, Han-Hyuk;Lee, Eun-Suk;Choi, Joong-Min;Han, Jung-Hyun;Yi, Jun-Ho
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.5S
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    • pp.1696-1707
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    • 2000
  • With the proliferation of electronic commerce (EC), the product items which are transacted and the user classes who utilize the EC are spread rapidly. Many users have to expend time and effort in searching of products an or the shopping malls which deal with the products. For his reason, the intelligent retrieval of both malls and products based on an intelligent software agent has been raised as a hot issue. In this paper we have constructed an ontology server that is an essential constituent for agent-based intelligent EC. And also we have designed and implemented a use adapted personalized product search function based on the ontology that are registered in the server.

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Metabolic engineering of Vit C: Biofortification of potato

  • Upadhyaya, Chandrama P.;Park, Se-Won
    • Proceedings of the Plant Resources Society of Korea Conference
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    • pp.14-14
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    • 2010
  • Vitamin C (ascorbic acid) is an essential component for collagen biosynthesis and also for the proper functioning of the cardiovascular system in humans. Unlike most of the animals, humans lack the ability to synthesize ascorbic acid on their own due to a mutation in the gene encoding the last enzyme of ascorbate biosynthesis. As a result, vitamin C must be obtained from dietary sources like plants. In this study, we have developed two different kinds of transgenic potato plants (Solanumtuberosum L. cv. Taedong Valley) overexpressing strawberry GalUR and mouse GLoase gene under the control of CaMV 35S promoter with increased ascorbic acid levels. Integration of the these genes in the plant genome was confirmed by PCR and Southern blotting. Ascorbic acid(AsA) levels in transgenic tubers were determined by high-performance liquid chromatography(HPLC). The over-expression of these genes resulted in 2-4 folds increase in AsA intransgenic potato and the levels of AsA were positively correlated with increased geneactivity. The transgenic lines with enhanced vitamin C content showed enhanced tolerance to abiotic stresses induced by methyl viologen(MV), NaCl or mannitol as compared to untransformed control plants. The leaf disc senescence assay showed better tolerance in transgenic lines by retaining higher chlorophyll as compared to the untransformed control plants. Present study demonstrated that the over-expression of these gene enhanced the level of AsA in potato tubers and these transgenics performed better under different abiotic stresses as compared to untransformed control. We have also investigated the mechanism of the abiotic stress tolerance upon enhancing the level of the ascorbate in transgenic potato. The transgenic potato plants overexpressing GalUR gene with enhanced accumulation of ascorbate were investigated to analyze the antioxidants activity of enzymes involved in the ascorbate-glutathione cycle and their tolerance mechanism against different abiotic stresses under invitro conditions. Transformed potato tubers subjected to various abiotic stresses induced by methyl viologen, sodium chloride and zinc chloride showed significant increase in the activities of superoxide dismutase(SOD, EC 1.15.1.1), catalase, enzymes of ascorbate-glutathione cycle enzymes such as ascorbate peroxidase(APX, EC 1.11.1.11), dehydroascorbate reductase(DHAR, EC 1.8.5.1), and glutathione reductase(GR, EC 1.8.1.7) as well as the levels of ascorbate, GSH and proline when compared to the untransformed tubers. The increased enzyme activities correlated with their mRNA transcript accumulation in the stressed transgenic tubers. Pronounced differences in redox status were also observed in stressed transgenic potato tubers that showed more tolerance to abiotic stresses when compared to untransformed tubers. From the present study, it is evident that improved to lerance against abiotic stresses in transgenic tubers is due to the increased activity of enzymes involved in the antioxidant system together with enhanced ascorbate accumulated in transformed tubers when compared to untransformed tubers. At moment we also investigating the role of enhanced reduced glutathione level for the maintenance of the methylglyoxal level as it is evident that methylglyoxal is a potent cytotoxic compound produced under the abiotic stress and the maintenance of the methylglyoxal level is important to survive the plant under stress conditions.

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Fuzzy AHP and FCM-driven Hybrid Group Decision Support Mechanism (퍼지 AHP와 퍼지인식도 기반의 하이브리드 그룹 의사결정지원 메커니즘)

  • Kim, Jin-Sung;Lee, Kun-Chang
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • pp.239-250
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    • 2003
  • In this research, we propose a hybrid group decision support mechanism (H-GDSM) based on Fuzzy AHP (Analytic Hierarchy Process) and FCM (Fuzzy Cognitive Map). The AHP elicits a corresponding priority vector interpreting the preferred information among the decision makers. Corresponding vector was composed of the pairwise comparison values of a set of objects. Since pairwise comparison values are the judgments obtained from an appropriate semantic scale. However, AHP couldn't represent the causal relationship among information, which were used by decision makers. In contrast to AHP, FCM could represent the causal relationship among variables or information. Therefore, FCMs were successfully developed and used in several ill-structured domains, such as strategic decision-making, policy making, and simulations. Nonetheless, many researchers used subjective and voluntary inputs to simulate the FCM. As a result of subjective inputs, it couldn't avoid the rebukes of businessman. To overcome these limitations, we incorporated the Fuzzy membership functions, AHP and FCM into a H-GDSM. In contrast to current AHP methods and FCMs, the H-GDSM method developed herein could concurrently tackle the pairwise comparison involving causal relationships under a group decision-making environment. The strengths and contributions of our mechanism were 1) handling of qualitative knowledge and causal relationships, 2) extraction of objective input value to simulate the FCM, 3) multi-phase group decision support based on H-GDSM. To validate our proposed mechanism we developed a simple prototype system to support negotiation-based decisions in electronic commerce (EC).

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Acetohydroxyacid Synthase

  • Duggleby, Ronald G.;Pang, Siew Siew
    • BMB Reports
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    • v.33 no.1
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    • pp.1-36
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    • 2000
  • Acetohydroxyacid synthase (EC 4.1.3.18) catalyses the first reaction in the pathway for synthesis of the branched-chain amino acids. The enzyme is inhibited by several commercial herbicides and has been subjected to detailed study over the last 20 to 30 years. Here we review the progress that has been made in understanding its structure, regulation, mechanism, and inhibition.

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Effects of chitosan on the decreased renal dipeptidase release by nitric oxide from renal proximal tubules

  • Yoon, Hyun-Joong;Park, Eun-Mi;Park, Haeng-Soon
    • Proceedings of the PSK Conference
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    • pp.319.2-319
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    • 2002
  • Chitin is a major component of the shells of crustacea such as crab. shrimp and crawfish. Renal dipeptidase (RDPase. EC 3.4.13.19), an ectoenzyme of renal proximal tubules. is covalently bound to outer leaflet of lipid bilayer via glycosylphosphatidylinositol (GPI)-anchor. The biological role of RDPase was suggested as the hydrolysis of dipeptide into free-amino acids before renal reabsorption. The underlying biochemical mechanism of decreased RDPase release was suggested as nitric oxide (NO) production. (omitted)

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Effects of Pertussis Toxin on Macrophage Activation

  • Lim, Suck-Ihn;An, Nyeon-Hyoung
    • Archives of Pharmacal Research
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    • v.15 no.2
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    • pp.146-151
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    • 1992
  • The aim of this study was to evaluate capability of pertussis toxin (PT) to active mouse macrophages. The investigations were undertaken to determine whether the role played by this toxin required the A-protomer of the toxin to ADP-ribosylate a guanine nucleotide binding protein (a class I activity) or was dependent on the binding of B-oligomer of the toxin to the surface of target cells (a Class II activity). The results of these experiments have established that the mechanism of macrophage activation with PT seems to be dependent upon a Class II activity of the toxin.

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Mechanism of Glycogen Biosynthesis by Glycogen Synthetase from Escherichia coil B (Escherichia coil B의 Glycogen Synthetase반응에 의한 글리코겐 생합성기작)

  • 양지영
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.6
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    • pp.1173-1176
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    • 1998
  • Glycogen synthetase[EC 2.4.1.21] in E. coli B was isolated and purified by sonication, ultracentri fugation, DEAE cellulose chromatography and gel chromatography. In the case of using glycogen or maltotriose as a primer in the enzyme reaction, 64% and 23.7% of labelled ADP glucose were incorporated into primer, respectively. 8.1% of labelled ADP glucose was polymerized into glycogen in enzymatic reaction without a primer.

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Overview of Hydrolysis : A Review Part II- Hydrolysis Application

  • Kim, Kwang-Jea
    • Elastomers and Composites
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    • v.55 no.2
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    • pp.137-146
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    • 2020
  • Part 1 provides a theoretical introduction of the hydrolysis mechanism, while Part 2 introduces other types of reaction mechanisms after hydrolysis in elastomer and PA66 composites. We reviewed the condensation reaction, which occurs after hydrolysis in bi-functional alkoxy silane (TESPD & TESPT), and investigated its effects on the mechanical properties of the composites. We also reviewed activators such as zinc soap, which enhances the mechanical properties of silica-silane-filled elastomer composites. The interaction parameter of silica-silane-filled elastomer composites [αC (alpha C)] were also discussed. The effects of hydrolysis on the mechanical property changes in plastic composites were compared and reviewed.

Solubility and Esterification Kinetics of Terephthalic Acid in Ethylene Glycol(II)- Effect of TPA Particle Size and Dissolution Mechanism - (에틸렌글리콜과 테레프탈산의 용해도 및 에스테르화 속도(II)-TPA 입자크기의 영향과 용해 기구-)

  • 최창남;양갑승
    • Textile Science and Engineering
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    • v.31 no.7
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    • pp.524-530
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    • 1994
  • In the esterification step of PET formation, we Investigated the effect of TPA particle sizes on the solubility and reactivity of TPA in EG to illuminate the mechanism of dissolution. The solubility was estimated by clear time and turbidity. The reactivity of TPA was determined by acid and saponification values. As the particle size of TPA decreased, both enhanced reactivity and solubility were introduced. The results suggest that small portion of TPA in EC is dissolved %rst the proton farmed in EG plays the role of an acid catalyst, then, the ester formed accelerates the dissolution and esterification of TPA.

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Autophagy Is a Potential Target for Enhancing the Anti-Angiogenic Effect of Mebendazole in Endothelial Cells

  • Sung, So Jung;Kim, Hyun-Kyung;Hong, Yong-Kil;Joe, Young Ae
    • Biomolecules & Therapeutics
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    • v.27 no.1
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    • pp.117-125
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    • 2019
  • Mebendazole (MBZ), a microtubule depolymerizing drug commonly used for the treatment of helminthic infections, has recently been noted as a repositioning candidate for angiogenesis inhibition and cancer therapy. However, the definite anti-angiogenic mechanism of MBZ remains unclear. In this study, we explored the inhibitory mechanism of MBZ in endothelial cells (ECs) and developed a novel strategy to improve its anti-angiogenic therapy. Treatment of ECs with MBZ led to inhibition of EC proliferation in a dose-dependent manner in several culture conditions in the presence of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) or FBS, without selectivity of growth factors, although MBZ is known to inhibit VEGF receptor 2 kinase. Furthermore, MBZ inhibited EC migration and tube formation induced by either VEGF or bFGF. However, unexpectedly, treatment of MBZ did not affect FAK and ERK1/2 phosphorylation induced by these factors. Treatment with MBZ induced shrinking of ECs and caused G2-M arrest and apoptosis with an increased Sub-G1 fraction. In addition, increased levels of nuclear fragmentation, p53 expression, and active form of caspase 3 were observed. The marked induction of autophagy by MBZ was also noted. Interestingly, inhibition of autophagy through knocking down of Beclin1 or ATG5/7, or treatment with autophagy inhibitors such as 3-methyladenine and chloroquine resulted in marked enhancement of anti-proliferative and pro-apoptotic effects of MBZ in ECs. Consequently, we suggest that MBZ induces autophagy in ECs and that protective autophagy can be a novel target for enhancing the anti-angiogenic efficacy of MBZ in cancer treatment.