• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.327-330
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• 1996

An amino acid antimetabolite named YS-460 was isolated from the culture filtrate of a newly isolated Actinomycetes identified as Streptomyces sp. Fermentation was carried out in the synthetic medium at 30$\circ$C for 5 days. Purification was done by ion exchange resin, active carbon, silica gel column chromatography and obtained 38 mg of pure active substance per liter of the broth. YS-460, an amino acid like substance, has the molecular formula of C$_{7}$H$_{11}$NO$_{3}$- Its structure determined to be furanomycin by spectral analysis. It is active against some bacteria on a chemically defined medium and reversed competitively by L-isoleucine and non-competitively by L-leucine and L-valine.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.242-242
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• 2005

• Bulletin of the Korean Chemical Society
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• v.7 no.4
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• pp.296-298
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• 1986

Carboxylic acid anhydrides are rapidly reduced with borane-lithium chloride (1:0.1) system to give corresponding alcohols (diols in the case of cyclic anhydride) quantitatively in tetrahydrofuran at room temperature. This reagent tolerates aromatic acid ester, nitro, and halide functional groups, however competitively reduces aliphatic ester and nitrile groups.

• The Journal of Society for e-Business Studies
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• v.5 no.1
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• pp.93-104
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• 2000

Domestic automotive industry is also facing the moment it should be with a competitively priced and highly qualified automotive ta compete with worldwide automotive makers of world market through global marketing and global sourcing. At this point, weve been studying xNX model of USA, Japan and Europe with OEMs, suppliers and KAMA(Korea Automotive Manufacturers Association) to give a network infrastructure of guaranteed service quality network performance, reliability, security and trouble handling. We hope all efforts above mentioned will make the whole industry more competitive and powerful.

• Archives of Pharmacal Research
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• v.13 no.2
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• pp.132-135
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• 1990

Polyhydroxystilbenes including resveratrol were reported to competitively inhibit monoamine oxidase-A-without structural relation with substrates and cynthetic inhibitors for the enzyme. We attempt to explore a plausible mechanism for their inhibitory activity on MAO-A. All the polyhydroxystilbenes tested showed the antioxidant activity on liver homogenate. Furthermore, the antioxidant activity turned out to closely correlate with the MAO-A inhibitory activity.

• The Korean Journal of Pharmacology
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• v.5 no.1
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• pp.35-38
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• 1969

1.On isolated atrial preparation of frog, effects of sympathomimetic amines were investigated. 2. Isoproterenol, epinephrine, norepinephrine, and phenylephrine produced positive chronotropic and inotropic effects. The relative potencies for the effects of these agents were: isoproterenol > epinephrine> norepinephrine> phenylephrine. Methoxamine had no effects or depressed the atria. 3. Pronethalol antagonized the positive effects of these adrenergic agents competitively. 4. Regitine did not affect the effects of these agents. 5. These data indicate that the adrenergic agents activate the atrial tissue of the frog via stimulation of adrenergic beta-receptor.

• Bulletin of the Korean Chemical Society
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• v.8 no.5
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• pp.414-418
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• 1987

Electrochemical reduction of dibenzoylmethane was studied on mercury electrode by means of cyclic voltammetry, polarography and potentiostatic measurements in ethanol-water system. In acidic solutions monomeric pinacol was produced by irreversible two-electron process while monomeric and dimeric pinacol were competitively produced by the same process in neutral solution. However, in basic solution the dimeric pinacol was mostly produced through radical by irreversible one-electron transfer process. Mechanisms of the reduction of dibenzoylmethane are deduced from Tafel slope, pH dependance and reaction order with respect to the concentration of dibenzoylmethane in the solution of various pH.

• Bulletin of the Korean Chemical Society
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• v.22 no.11
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• pp.1207-1212
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• 2001

A new photochemically bifunctional epoxy and dimethacrylate compounds were synthesized for investigating the photosensitivity under UV irradiation. Photosensitivity of the synthesized chalcone-based compounds was investigated by using UV-visible absorption and Fourier transformed infrared (FT-IR) spectroscopies. The result of spectroscopic analysis substantiated that the two chalcone-based compounds have functions of both photocrosslinking and photopolymerization by UV exposure in the presence of photoinitiator. Two kinds of photochemical reactions proceeded competitively during UV exposure. Particularly, we studied the effect of photopolymerization on the rate of photocrosslink due to cycloaddition in the two oligomeric compounds.

• Journal of Plant Biology
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• v.20 no.2
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• pp.91-101
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• 1977

Using barley seeds (Hordeum sativum Jess, var.), the influences of gibberellic acid (GA) and indole-3-acetic acid(IAA) on the amylase synthesis and that of the nucleic acid metabolism were investigated. 1. With the deembrynized barley seeds, the increase of amylase treated with a $10^{-5}M$ of GA and the decrease of amylase treated with $10^{-5}M$IAA were matched by a proportionate increase and decrease in the amount of RNA. The influence of the hormones on the RNA synthesis has appeared immediately after the treatment but on the amylase synthesis it has appeared 8 hours later. But no influence on the DNA synthesis was observed on both hormones. 2. The amylase from deembryonized barley seeds treated with GA and IAA have been fractionated by gel filteration on Sephadex G-100. The amylase components showed four fractions on both enzymes treated with GA and IAA. Fraction I(FI) was differed from fraction Ⅵ(FIV) in Km value and the effects of temperature, pH and metal ions. On the basis of their emzymatic properties, it was considered that the FI was $\beta$-amylase and FIV was $\alpha$-amylase. The influences of GA and IAA on each fractions appeared to be similar but on the amylase units per souble protein, IAA inhibited the production of amylase FIV while it promoted that of amylase FI. 3. An experiment was conducted to determine whether IAA inhibits GA-promoted amylase synthesis competitively or non-competitively. Using a Lineweaver-Burk plot, it was clear that IAA was acting in a non-competitive fashion. From this, IAA was probably not competing with GA at the same site, but it was acting at some other site which resutled in partial blocking of the action of GA on the amylase synthesis.

• Applied Chemistry for Engineering
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• v.18 no.4
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• pp.350-355
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• 2007

The effect of moisture in flue gas on SCR reaction of NMO (Natural Manganese Ore) was studied. The experiments were performed over NMO with NO, $NH_3$ at independent condition or simultaneous condition. $NH_3$ can be oxidized at low temperature by the lattice oxygen in NMO catalyst. The concentration of NO and $NO_2$ by $NH_3$ oxidation with moisture is higher above $300^{\circ}C$ than that without moisture. Moisture would competitively adsorb with NO and $NH_3$ on NMO catalyst. It caused poor NOx conversion to compete against $H_2O$. Besides the NOx conversion efficiency was reduced at below $250^{\circ}C$ because of the dipped $H_2O$ competitively adsorbed $NH_3$. The reactivity of NMO varied with the calcination temperature and the optimum calcination temperature was $400^{\circ}C$ regardless $H_2O$.