• Title/Summary/Keyword: Science and Technology Park

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Anti-herpetic Activity of Various Medicinal Plant Extracts

  • Woo, Eun-Rhan;Kim, Hyoung-Ja;Jong, Hwan-Kwak;Lim, Young-Kwern;Park, Seong-Kyu;Kim, Hae-Soo;Lee, Chong-Kyo;Park, Hokoon
    • Archives of Pharmacal Research
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    • v.20 no.1
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    • pp.58-67
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    • 1997
  • In order to find antiviral compounds against Herpes simplex virus type I (HSV-1) and II (HSV2) from natural products, a convenient virus-induced cytopathic effect (CPE) inhibition assay was introduced. More than 300 fractions were prepared by solvent fractionation from sixty collected plants or purchased herbal medicines, and their anti-herpetic activities were evaluated. Among them, several medicinal plants showed potent anti-herpetic activity. Selective indexes (SI) of the EtOAc extract of Caraganae Radix (Caragana sinica) against HSV-1 and HSV-2 were more than 8.06 and 24.79, SI of the MeOH extract of Acer okamotoanum leaves were 3.92 and 3.51, SI of the $CH_{2}Cl_{2}$ extract of Veratri Rhizoma et Radix (Veratrum patulum) were 5.49 and 1.31 and SI of the MeOH extract of aerial part of Osmundae Rhizoma (Osmunda japonica) were more than 3.45 and 1.25, respectively.

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New Tactics for Stereospecificity in Metallocene-based Olefin Polymerization

  • Kim, Seong-Kyun;Park, Sung-Jin;Kim, Hwa-Kyu;Yoon, Seung-Woong;Lee, Jun-Seong;Park, Myung-Hwan;Do, Young-Kyu
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.221-221
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    • 2006
  • The stereochemical control in polypropylenes and styrene-ethylene copolymers based on homogeneous single-site polymerization catalysts has received great attention since the stereocpecificity is one of the key factors in tailoring the polymer properties. Thus, we have developed new tactics for isospecificity in propylene polymerization with the unbridged metallocenebased systems and syndiospecific styrene-styrene sequence in styrene-ethylene copolymerization with the group 4 metallocene system. Brief details of the synthesis, structures and the polymerization behavior of a set of new metallocene catalysts will be presented.

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Isolation of Deletion Mutants by Reverse Genetics in Caenorhabditis elegans

  • Park, Byung-Jae;Lee, Jin ll;Lee, Jiyeon;Kim, Sunja;Choi, Kyu Yeong;Park, Chul-Seung;Ahn, Joohong
    • Animal cells and systems
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    • v.5 no.1
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    • pp.65-69
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    • 2001
  • Obtaining mutant animals is important for studying the function of a particular gene. A chemical mutagenesis was first carried out to generate mutations in C. elegans. In this study, we used ultraviolet-activated 4,5',8-trimethylpsoralen to induce small deletion mutations. A library of mutagenized worms was prepared for recovery of candidate animals and stored at $15^{\circ}C$ during screening instead of being made into a frozen stock library. In order to isolate deletion mutations in target genes, a polymerase chain reaction (PCR)-based screening method was used. As a result, two independent mutants with deletions of approximately 1.0 kb and 1.3 kb were isolated. This modified and improved reverse genetic approach was proven to be effective and practical for isolating mutant animals to study gene function at the organismal level.

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White Light Generation from Single Gallium Oxide Nanoparticles co-doped with Rare-Earth Metals

  • Patil, Prashant;Park, Jinsung;Lee, Seung Yong;Park, Jong-Ku;Cho, So-Hye
    • Applied Science and Convergence Technology
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    • v.23 no.5
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    • pp.296-300
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    • 2014
  • The synthesis of pure and rare-earth doped gallium oxide (${\beta}-Ga_2O_3$) nanoparticles is reported. The synthesized nanoparticles are characterized with XRD, TEM, and PL analyses. Strong blue emission is observed from un-doped gallium oxide nanoparticles, while nanoparticles doped with $Eu^{3+}$ and $Tb^{3+}$ give strong red and green emissions, respectively. When doped with $Eu^{3+}$ and $Tb^{3+}$ together, gallium oxide nanoparticles emit white light. The CIE coordinate of the emitted light was found to be (0.33, 0.33), which is well within the white light region.

Helimagnetic Order in the Cubic FeGe Nanowires

  • Park, Tae-Eon;Min, Byoung-Chul;Seo, Dongjea;Chang, Hye Jung;Kim, Sungwook;Park, Youn Ho;Choi, Heon-Jin;Chang, Joonyeon
    • Proceedings of the Korean Magnestics Society Conference
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    • 2016.05a
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    • pp.98-98
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    • 2016
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