• Title/Summary/Keyword: elucidation

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Secondary Metabolites of Volvariella bombycina and Their Inhibitory Effects on Melanogenesis

  • Xu, Guang-Hua;Choo, Soo-Jin;Kim, Young-Hee;Ryoo, In-Ja;Seok, Soon-Ja;Ahn, Jong-Seog;Yoo, Ick-Dong
    • Journal of Microbiology and Biotechnology
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    • v.20 no.1
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    • pp.78-81
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    • 2010
  • Four compounds were isolated from the culture broth of Volvariella bombycina and they were identified as ergosta-4,6,8(14),22-tetraene-3-one (1), ergosterol peroxide (2), indole-3-carboxaldehyde (3), and indazole (4) by interpretation of spectroscopic data. Among them, compound 2 exhibited melanogenesis inhibitory effect in cultured B16 mouse melanoma cells.

Metastasis-associated Factors Facilitating the Progression of Colorectal Cancer

  • Zhang, Yao-Yao;Chen, Bin;Ding, Yan-Qing
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.6
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    • pp.2437-2444
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    • 2012
  • Tumor metastasis remains the principal cause of treatment failure and poor prognosis in patients with colorectal cancer. It is a multistage process which includes proteolysis, motility and migration of cells, proliferation in a new site, and neoangiogenesis. A crucial step in the process of intra- and extra-vasation is the activation of proteolytic enzymes capable of degrading the extracellular matrix (ECM). In this stage, urokinase plasminogen activator receptor (uPAR) and matrix metalloproteinases (MMPs) are necessary. Micrometastases need the presence of growth factor and vascular growth factor so that they can form macrometastasis. In addition, cell adhesion molecules (CAMs) and guanine nucleotide exchange factors (GEFs) play important roles in the progression of colorectal cancer and metastatic migration. Further elucidation of the mechanisms of how these molecules contribute will aid in the identification of diagnostic and prognostic markers as well as therapeutic targets for patients with colorectal metastasis.

A Study on Animation Cubic Character Modelling Based on Plasticity (조형성을 바탕으로 한 애니메이션 입체 캐릭터 모델링 연구)

  • Choi, Don-Ill
    • Cartoon and Animation Studies
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    • s.6
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    • pp.116-131
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    • 2002
  • Character plays an important role not merely in animation but also in the modern image industry. From this perspective a new academic approach to and an analysis of character seems of much significance. With this in view this study carried out an elucidation of the basic factors and concept of plasticity for the creation of animation character on the basis of animation structural elements. Furthermore, an inquiry was conducted into fundamental requirements and factors of animation characters, human anatomy serving as the basis of forms for animation character modelling, the characteristics and techniques for creating animation cubic character, and then suggested a method of creation. In this process it was revealed that integral cubic character was applied to diverse animations, that character of high density was prerequisite for the creation of creative and effective animations, and that cubic character plasticity played a catalytic role in activation popular sympathy and the character industry.

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Elucidation of Central Line Refocusing in Quadrupolar Echo Formation

  • Han, Duk-Young
    • Journal of the Korean Magnetic Resonance Society
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    • v.3 no.1
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    • pp.27-35
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    • 1999
  • Quadrupolar interaction is a strong line broadening agent for nuclei of half-integer spin except the central line. The two-pulse quadrupolar echo technique is widely used, which refocuses the quadrupolar broadening. Echo formation is due to the cancellation of quadrupolar broadening effect by the applied two pulses. Since the central line is not quadrupolar broadened, it should not be involved in the echo formation. However, the central line peak always appears in experiments. This is explained qualitatively here by close examination on the time development of individual coherence. This explanation is used to predict the number of echoes that will be formed with 2 pulse sequence for nuclei of I=3/2, 5/2, 7/2, 9/2 with ease.

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Synthesis and Antifungal Activities of Some Aryl (3-Methyl-Benzofuran-2-yl) Ketoximes

  • Benkli, Kadriye;Gundogdu-Karaburun, Nalan;Karaburun, Ahmet-Cagrl;Ucucu, Umit;Demirayak, Seref;Kiraz, Nuri
    • Archives of Pharmacal Research
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    • v.26 no.3
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    • pp.202-206
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    • 2003
  • In this study, some aryl (3-methyl-benzofuran-2-yl) ketoximes and their ethers and esters were synthesised. The structure elucidation of the compounds was performed by IR, $^1H-NMR$, MASS spectroscopy and elemental analyses. Antifungal activities of the compounds were examined and moderate activity was obtained.

The anti-inflammatory activity of Kalopanax pictus bark extract (V). Effects of saponins from KP on $NF-_K/B$ and elastase activities

  • Li, Da-Wei;Ahn, Kwang-Seok;Joo, Eun-Ji;Cho, So-Yean;Jeong, Choon-Sik;Lee, Eun-Bang;Kim, Yeong-Shik
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.255.3-256
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    • 2002
  • In the previous studies. we confirmed the anti-inflammatory components of Kalopanax pictus bark using activity-guided fractionation in vivo. For the elucidation of anti-inflammatory mechanism, we evaluated the effects of these components on the inhibition of NF-$\sub$K/B activity and human leukocyte elastase. A cell-based assay system developed in our laboratory was used in transfectant RAW 264.7 cells. (omitted)

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Supramolecular Nanomaterials Derived from Self-Assembly of Dendritic Building Blocks

  • Park, Chi-Young;Lee, Sang-Wha;Lim, Ji-No;Lim, Moon-Seob;Kim, Chul-Hee
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.91-92
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    • 2006
  • The fine-tuned dendrons provide unique supramolecular self-assemblies in various environments such as in water, organic media, and solid-liquid interfaces. They form nanotubes, vesicles, thin films, columns, lamellar nanoribbons depending on the condition of self-assembly process. Unique characteristics of self-assembly of the amide dendrons are described. In addition, elucidation of the structural correlation between the building blocks and the assemblies, stabilization of assembled structure, and transformation of supramolecular assemblies by using external stimuli. Particular emphasis is placed on the formation of cyclodextrin-covered organic nanotubes derived from self-assembly of amide dendrons and their supramolecular transformation. Finally, unique biosensory characteristics of the self-assembled nanotubes will be discussed.

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Molecular biological approaches to study the function and regulation of citrate synthase genes in saccharomyces cerevisiae

  • Kim, Kwang-Soo;Rosankranz, Mark;Guarente, Leonard
    • The Microorganisms and Industry
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    • v.12 no.2
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    • pp.30-35
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    • 1986
  • Almost all of the aerobic organisms contain citric acid cycle (or, tricarboxylic acid cycle). This cycle is involved both in energy metabolism and biosynthetic reactions; generation of NADH which derives the synthesis of chemical energy, ATP, and provision of intermediates needed for the biosynthesis. Because of its importance in the cellular metabolism, the regulation of the TCA cycle and its component enzymes has been extensively studied by many biologists (7,28). Citrate synthase is resposible for the initial step of the cycle and has been recognized as the rate limiting step (14,121,26). Understanding of the mechanism of the expression of citrate synthase should be a key step for the elucidation of the regulation of the TCA cycle in the cell metabolism.

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The 1H and 13C NMR Data of 19 Methoxyflavonol Derivatives

  • Park, Young-Hee;Moon, Byoung-Ho;Lee, Eun-Jung;Hong, Sun-Hee;Lee, Sun-Hee;Lim, Yoong-Ho
    • Bulletin of the Korean Chemical Society
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    • v.29 no.1
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    • pp.81-84
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    • 2008
  • In the present study, we report 1H and 13C NMR data of 19 methoxyflavonol derivatives with different substitution patterns on A- and B-ring. In addition, the influence of the methoxy substituents in A- and B-ring on the 1H and 13C NMR chemical shifts is discussed: the 1H and 13C chemical shifts of and the number of methoxyl groups provided information allowing elimination of many structural isomers from consideration and in certain instances greatly simplified structural elucidation.

Elucidation of the Noise in Corrosion of Aluminum Foil

  • Chiba, Atsushi;Hattori, Atsushi;Wu, Weng-Chang
    • Corrosion Science and Technology
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    • v.3 no.3
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    • pp.102-106
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    • 2004
  • Al foil used was 99.9 and 99.99 %. Test solution used was NaCl solution. The noise was determined using controlled potential electrolysis at -200 and -700 mV vs. NHE. The current fluctuation was caused by breakdown and repaired process of aluminum oxide film. The current fluctuation value of noise was proportion to degree of growth. The number of noise was proportion to the number of pit. The examining of current flutulation value and number of noise could be evaluated corrosion. A 99.99 % Al foil was the mostly crystal of {100} plane, and showed three-dimensional, as azimuth pit with along the direction of this place piled up. A 99.9 % Al foil was polycrystal, and in order of (311) >(222) >(200) >(111) plane. The azimuth pit did not occurred as the dissolution was occurred from each plane.