3,301 research outputs found

    Information Technology and Law: Computer Programs and Intellectual Property Law in the US, Europe, Japan and Korea

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    by Dae-Hwan Koo, Pakyoungsa, 2005, Pp. xvi, 509. \28,000INFORMATION TECHNOLOGY AND LAW-COMPUTER PROGRAMS AND INTELLECTUAL PROPERTY LAW IN THE US, EUROPE, JAPAN AND KOREA- (hereinafter Book) deals with the protection of software, a subject of essential importance to practitioners as well as legal scholars. There has been a steady flow of literature on this topic in Korea for more than the past decade. Nevertheless, much of the debate has been focused only upon the protection of software from the perspective of particular types of intellectual property such as trade secrets, copyright, patent, and contract law. This Book systematically deals with this topic, and comparatively analyzes the protection of software in the US, Europe, Japan and Korea

    Neuroprotective Effects of Astaxanthin in Oxygen-Glucose Deprivation in SH-SY5Y Cells and Global Cerebral Ischemia in Rat

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    Astaxanthin (ATX), a naturally occurring carotenoid pigment, is a powerful biological antioxidant. In the present study, we investigated whether ATX pharmacologically offers neuroprotection against oxidative stress by cerebral ischemia. We found that the neuroprotective efficacy of ATX at the dose of 30 mg/kg (n = 8) was 59.5% compared with the control group (n = 3). In order to make clear the mechanism of ATX neuroprotection, the up-regulation inducible nitric oxide synthase (iNOS) and heat shock proteins (HSPs) together with the oxygen glucose deprivation (OGD) in SH-SY5Y cells were also investigated. The induction of various factors involved in oxidative stress processes such as iNOS was suppressed by the treatment of ATX at 25 and 50 µM after OGD-induced oxidative stress. In addition, Western blots showed that ATX elevated of heme oxygenase-1 (HO-1; Hsp32) and Hsp70 protein levels in in vitro. These results suggest that the neuroprotective effects of ATX were related to anti-oxidant activities in global ischemia

    Folding machineries displayed on a cation-exchanger for the concerted refolding of cysteine- or proline-rich proteins

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    <p>Abstract</p> <p>Background</p> <p><it>Escherichia coli </it>has been most widely used for the production of valuable recombinant proteins. However, over-production of heterologous proteins in <it>E. coli </it>frequently leads to their misfolding and aggregation yielding inclusion bodies. Previous attempts to refold the inclusion bodies into bioactive forms usually result in poor recovery and account for the major cost in industrial production of desired proteins from recombinant <it>E. coli</it>. Here, we describe the successful use of the immobilized folding machineries for <it>in vitro </it>refolding with the examples of high yield refolding of a ribonuclease A (RNase A) and cyclohexanone monooxygenase (CHMO).</p> <p>Results</p> <p>We have generated refolding-facilitating media immobilized with three folding machineries, mini-chaperone (a monomeric apical domain consisting of residues 191–345 of GroEL) and two foldases (DsbA and human peptidyl-prolyl <it>cis-trans </it>isomerase) by mimicking oxidative refolding chromatography. For efficient and simple purification and immobilization simultaneously, folding machineries were fused with the positively-charged consecutive 10-arginine tag at their C-terminal. The immobilized folding machineries were fully functional when assayed in a batch mode. When the refolding-facilitating matrices were applied to the refolding of denatured and reduced RNase A and CHMO, both of which contain many cysteine and proline residues, RNase A and CHMO were recovered in 73% and 53% yield of soluble protein with full enzyme activity, respectively.</p> <p>Conclusion</p> <p>The refolding-facilitating media presented here could be a cost-efficient platform and should be applicable to refold a wide range of <it>E. coli </it>inclusion bodies in high yield with biological function.</p

    One-pot Enzymatic Synthesis of Deoxy-thymidine-diphosphate (TDP)-2-deoxy-∝-d-glucose Using Phosphomannomutase

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    Production of deoxy-thymidine-diphosphate (TDP)-sugars as substrates of glycosyltransferases, has been one of main hurdles for combinatorial antibiotic biosynthesis, which combines sugar moiety with aglycon of various antibiotics. Here, we report the one-pot enzymatic synthesis of TDP-2-deoxy-glucose employing high efficient TMP kinase (TMK; E.C. 2.7.2.12), acetate kinase (ACK; E.C. 2.7.1.21), and TDP-glucose synthase (TGS; E.C. 2.7.7.24) with phosphomannomutase (PMM; E.C. 5.4.2.8). In this study, replacing phosphoglucomutase (PGM; E.C. 5.4.2) by PMM from Escherichia coli gave four times higher specific activity on 2-deoxy-6-phosphate glucose, suggesting that the activity on 2-deoxy-glucose-6-phosphate was mainly affected by PMM activity, not PGM activity. Using an in vitro system starting from TMP and 2-deoxy-glucose-6-phosphate glucose, TDP-2-deoxy-glucose (63% yield) was successfully synthesized. Considering low productivity of NDP-sugars from cheap starting materials, this paper showed how production of NDP-sugars could be enhanced by controlling mutase activity

    Molecular cloning and biochemical characterization of a novel erythrose reductase from Candida magnoliae JH110

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    <p>Abstract</p> <p>Background</p> <p>Erythrose reductase (ER) catalyzes the final step of erythritol production, which is reducing erythrose to erythritol using NAD(P)H as a cofactor. ER has gained interest because of its importance in the production of erythritol, which has extremely low digestibility and approved safety for diabetics. Although ERs were purified and characterized from microbial sources, the entire primary structure and the corresponding DNA for ER still remain unknown in most of erythritol-producing yeasts. <it>Candida magnoliae </it>JH110 isolated from honeycombs produces a significant amount of erythritol, suggesting the presence of erythrose metabolizing enzymes. Here we provide the genetic sequence and functional characteristics of a novel NADPH-dependent ER from <it>C. magnoliae </it>JH110.</p> <p>Results</p> <p>The gene encoding a novel ER was isolated from an osmophilic yeast <it>C. magnoliae </it>JH110. The ER gene composed of 849 nucleotides encodes a polypeptide with a calculated molecular mass of 31.4 kDa. The deduced amino acid sequence of ER showed a high degree of similarity to other members of the aldo-keto reductase superfamily including three ER isozymes from <it>Trichosporonoides megachiliensis </it>SNG-42. The intact coding region of ER from <it>C. magnoliae </it>JH110 was cloned, functionally expressed in <it>Escherichia coli </it>using a combined approach of gene fusion and molecular chaperone co-expression, and subsequently purified to homogeneity. The enzyme displayed a temperature and pH optimum at 42°C and 5.5, respectively. Among various aldoses, the <it>C. magnoliae </it>JH110 ER showed high specific activity for reduction of erythrose to the corresponding alcohol, erythritol. To explore the molecular basis of the catalysis of erythrose reduction with NADPH, homology structural modeling was performed. The result suggested that NADPH binding partners are completely conserved in the <it>C. magnoliae </it>JH110 ER. Furthermore, NADPH interacts with the side chains Lys252, Thr255, and Arg258, which could account for the enzyme's absolute requirement of NADPH over NADH.</p> <p>Conclusions</p> <p>A novel ER enzyme and its corresponding gene were isolated from <it>C. magnoliae </it>JH110. The <it>C. magnoliae </it>JH110 ER with high activity and catalytic efficiency would be very useful for <it>in vitro </it>erythritol production and could be applied for the production of erythritol in other microorganisms, which do not produce erythritol.</p

    Recurrence of Completely Excised Arteriovenous Malformation: Review of the Literatures and Possible Explanation

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    The authors report a case of recurrent arteriovenous malformation (AVM), which has been completely removed and disappeared on postoperative angiography four years ago. Initially, at the age of nine years, she presented intracerebral hematoma. The angiography demonstrated an aneurysm and AVM nidus located in the posterior frontal area, fed by the branches of the anterior and middle cerebral arteries. Eleven days after the ictus, rebleeding occurred, so left fronto-parietal craniotomy was done emergently. The hematoma and AVM nidus with aneurysm were removed. Her postoperative course was uneventful and postoperative angiography showed that the AVM had been completely excised. However, four years later, sudden focal motor seizure on right leg developed. Magnetic resonance (MR) images and angiography demonstrated that the AVM reappeared on the previously operated region. Extirpation of the recurrent AVM was carried out. We do emphasize a long term follow-up MR images or a repeated angiography is essential to confirm the complete absence after excision of the AVM

    Modelling wave-induced current at haeundae beach on orthogonal curvilinear grid by using CST3D

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    Haeundae Beach is sandy beach at Busan, Korea. Haeundae Beach is about 1.5 km- long enclosed by two headlands. The normal direction of the beach is between south and south-east. Tidal current at the site is not negligible, and waves are relatively high during monsoon and winter seasons. Currents were measured at nine points along Haeundae Beach on 4 June 2008 by using GPS-equipped drogues. Bathymetry around Haeundae Beach was surveyed on 7 August 2007 and 12 November 2007 by using an echo-sounder; wave, tide, and tidal current were measured between the two survey days, so that bathymetric change at the beach was obtained from the two surveys. The measured current vectors may include wave- induced current element, tidal current element, and wind-induced current. Seasonal sediment transport pattern at Haeundae Beach, Busan, Korea is known to be simple, according to previous observation. Typically sediment moves eastward, while sediment moves westward in winter. Tidal current contributes to long-term bathymetric change at the beach by transporting small-sized sediment

    Resonance of Domain Wall in a Ferromagnetic Nanostrip: Relation Between Distortion and Velocity

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    The resonance of the magnetic domain wall under the applied field amplifies its velocity compared to the one-dimensional model. To quantify the amplification, we define the distortion variation rate of the domain wall that can represent how fast and severely the wall shape is variated. Introducing that rate gives a way to bring the resonance into the one-dimensional domain wall dynamics model. We obtain the dissipated energy and domain wall velocity amplification by calculating the distortion variation rate. The relationship between velocity and distortion variation rate agrees well with micromagnetic simulation.Comment: 15 pages, 4 figure
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