• Korean Journal of Weed Science
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• v.17 no.2
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• pp.199-206
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• 1997

Chlorsulfuron, an acetolactate-synthase-inhibiting sulfonylurea herbicide, induces many metabolic and physiological changes in susceptible plants. The objective of this study was to determine to what extent chlorsulfuton-induced phytotoxicity was due to a shortage of final products(the branched-chain amino acids valine, leucine, and isoleucine) or to an accumulation of a toxic metabolite(2-ketobutyrate), or both, in a susceptible species. Chlorsulfuron-treated canola seedlings showed growth inhibition and injury symptoms that included chlorosis, downward leaf rolling, and accumulation of anthocyanins. Supplementation with valine, leucine, and isoleucine prevented the chlorsulfuron-induced growth inhibition and injury symptoms only partially, suggesting that factor(s) other than a shortage of the branched-chain amino acids also are involved in the phytotoxicity. Canola seedlings treated with 2-ketobutyrate showed reduced growth, but they showed different changes in metabolites than seedlings treated with chlorsulfuron. The results suggest that 2-ketobutyrate is not involved in chlorsulfuron-induced phytotoxicity. We conclude that chlorsulfuron-induced phytotoxicity is due at least in part to a shortage of branched-chain amino acids.

• Polymer(Korea)
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• v.36 no.2
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• pp.245-250
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• 2012

Branched polypropylenes (PP) with long chain branch were prepared by solid state reaction with three different branching agent of 0.3 wt% content. The chemical structures, non-isothermal crystallization behavior and complex viscosity of the branched PP were investigated by FTIR, DSC, optical microscope, and dynamic rheological measurement. The chemical structure of the branched PP was confirmed by the existence of =C-H stretching peak of the branching agent at 3100 $cm^{-1}$. There was no distinct change in melting temperature in case of PP-D-0-3 and PP-F-0-3, but PP-H-0-3 indicated a decrease in melting temperature. The decrease in melting temperature was interpreted by the fact that the degradation reaction of PP was more dominant than branched reaction, and confirmed by a decrease in complex viscosity. The non-isothermal crystallization behavior of the branched PP was analyzed using by Avrami equation. The Avrami exponent of PP was 3, and the values of the branched PP with DVB and FS were below 3. The activation energy of PP calculated by Kissinger method was 25 kJ/mol, and there were no big difference in activation energies of the branched PPs compared to PP.

• The Korean Journal of Mycology
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• v.29 no.2
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• pp.91-98
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• 2001

The mycelial morphology during submerged cultivation of Ganoderma ludium using by air-lift fermenter system were analyzed by image processing system and the characterization of mycelial morphology were investigated. In submerged culture using medium with different ammonium phosphate concentrations, the various morphological forms of G. lucidum mycelium were observed. The filamentous forms such as non-branched long filamentous mycelium, non-branched short mycelium, branched long filamentous mycelium, branched short mycelium, entangled mycelium and clump were observed, and also, and also, the pelleted forms such as smooth pellet, rough pellet and hollow rough pellet were observed. The mycelial morphology was changed from the filamentous to the pelleted forms by addition of ammonium phosphate. The fractal dimensions of pelleted and filamentous forms were 1.05 and 1.3, respectively, while the fractal dimension of mixtures of pelleted and filamentous forms was 1.16. Therefore, the fractal dimension was found to be more effective index for the detection of the mycelial morphology and morphological change during batch cultivation. The circularity was also found to be useful for evaluating the surface growth of pelleted mycelium.

• Bulletin of the Korean Chemical Society
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• v.26 no.9
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• pp.1366-1368
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• 2005

The first synthesis of a 4'-branched carbocyclic C-nucleoside 11 was achieved via the key intermediate 6, which was prepared using Knovenagel type condensation from ketone derivative 4.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.3
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• pp.300-306
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• 1993

Speries-related meat flavors were investigated for red meats (bovine, porcine, caprine, and ovine). Volatile branched-chain fatty acids (VBCFAs) including 2-methylbutanoic, 3-methylbutanoic, 4-methylpentanoic, 2-ethylhexanoic, 4-methylhexanoic, 4-methyloctanoic, 6-methyloctanoic, 4-ethyloctanoic, 4-methylnonanoic, and 2-ethyldecanoic acids were identified in the meats from cow (bovine), pig (porcine), goats (caprine ; American white goat and Korean black goat), and lamb (ovine). Beef flavor of bovine meat was characterized by the basic meaty flavor, lacking in goaty and muttony flavor impacts due to low or absent in 4-methyl.octanoic and 4-ethyloctanoic acids. Porcine meat contained the least number of VBCFAs among sample species tested, and 3-methylbutanoic acid contributed to the unclean sweaty odor of pork. Caprine meat from Korean black and American white goats lacked in short VBCFAs (C5, C6, and C7) and contained 4-methyloctanoic and 4-ethyloctanoic acids contributing to the characteristic goaty flavor of caprine meat. Caprine meat flavor was distinctively characterized by 4-ethyloctanoic acid, while 4-methyloctanoic acid provides sweaty-muttony flavor to ovine meat. Although kinds of VBCFAs are same in two different varieties of caprine meats, meat sample from Korean black goat had stronger goaty odor and contained higher concentration of 4-ethyloctanoic acid than the meat sample from American white goat did.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.214-222
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• 2011

To examine the new practical utilization of mucilages in Opuntia humifusa, polysaccharides were isolated from O. humifusa and their anti-metastatic activity and structural analysis were carried out. In experimental lung metastasis of B16BL6 melanoma cells, prophylactically intravenous (i.v.) administration of the crude polysaccharide (CNC-0) from O. humifusa significantly inhibited lung metastasis in a dose-dependant manner. The main polysaccharide, CNC-Ia was purified to homogeneity from CNC-0 by two successive column chromatographies using DEAE-Sepharose FF and Sephadex G-100 and its structure was characterized. Molecular mass of CNC-Ia was estimated to be 700 kDa and it mainly consisted of arabinose, galactose and xylose in addition to two minor sugars such as rhamnose and fucose. Methylation analysis indicated that CNC-Ia comprised at least 18 different glycosyl linkages such as terminal Araf, 5-linked Araf, 4-linked Galp and terminal Xylp in addition to three characteristic linkages such as full branched Araf, 3,4,6-branched Galp and full branched Galp. To analyze the fine structure of CNC-Ia, it was sequentially digested by exo-${\alpha}$-L-arabinofuranosidase and endo-${\beta}$-1,4-D-galactanase. These analyses suggested that CNC-Ia belongs to be a highly branched Type I arabinogalactan which has a ($1{\rightarrow}4$)-${\beta}$-galactan backbone with arabinosyl oligosaccharide side chains.

• Polymer(Korea)
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• v.36 no.4
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• pp.440-447
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• 2012

The branched copolyester was synthesized and its molecular weight, $T_g$, 1/2 method temperature ($T_{1/2}$) and rheological properties were characterized for the application of toner binder. The linear copolyester had low molecular weight and melt elasticity obtained by dimethylterephthalate (DMT), ethylene glycol (EG) and 2,2-bis(4-(2-hydroxypropoxy) phenyl)propane (HPP). The branched copolyesters prepared with various branching agents such as 2-(hydroxymethyl)-2-ethylpropane-1,3-diol (trimethylol propane, TMP), 2,2-bi(hydroxymethyl)-1,3-propanediol (pentaerythritol, PER), 1,2,4-benzenetricarboxylic anhydride (trimellitic anhydride, TMA) and glycerol to improve the physical properties of the linear copolyester. The effect of branching agents on the molecular weight and melt elasticity of the branched copolyester was examined. The branched copolyesters prepared by adding over 15 mol% of branching agent showed relatively high molecular weight and melt elasticity, and $T_{1/2}$ value of $140^{\circ}C$. Therefore, the highly branched copolyesters were deemed suitable as a hot-melt toner of laser print process.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.2
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• pp.78-83
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• 2005

The optimum conditions of Cordyceps militaris mycelial growth, purification and characteristics of branched-chain amino acid aminotransferase [BCAT(EC 2.6.1.42)] in this mycelium were studied. Optimum pH, temperature and medium of culture of mycelia were 5.5, $22.5^{\circ}C$ and Hamada medium (HM), respectively. BCAT in homogenate of this mycelia was precipitated by 20-40% saturated solution of ammonium sulfate and then purified by DEAE (diethylaminoethyl)-Sephadex A-50 column chromatography with linear concentration gradient and Sephadex G-200 gel filtration. A single band of purified enzyme was detected on SDS-PAGE (sodium dodecylsulfate-polyacrylamide gel electrophoresis). Optimum pH and temperature of BCAT were found to be 7.8 and $29^{\circ}C$, respectively. It showed activity toward L-leucine, L-isoleucine and L-valine as a substrate. The Km values of this enzyme for L-leucine were determined to be 5.88 mM for L-leucine.

• Tribology and Lubricants
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• v.17 no.2
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• pp.109-115
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• 2001

The lubricating performance of 23 kinds of polyol ester base oils 〔POEs〕 having different branch shapes was investigated by using a four ball tribometer under boundary lubrication condition. All the polyol ester base oils used in this study were made up of polyhydric alcohols of two-four valence and normal or branched fatty acids of different carbon number. The wear characteristics of polyol ester base oils are different from those of mineral oil, strongly affected by the branch shapes of fatty acids in their molecles. In particular, the polyol ester base oils having normal fatty acids such as n-octanoic acid, n-nonanoic acid etc. show much better wear performance than POEs having branched fatty acids such as 2-ethylhexanoic acid, 3,5,5-trimethyl hexanoic acid, etc. As the carbon chain length of normal fatty acids, in case of POEs of normal fatty acids, is increased, their wear rate is decreased and, in case of POEs of branched fatty acids, as the degree of branch of branched fatty acids is decreased, their wear rate is decreased. All the wear results of polyol ester base oils could be reasonably explained by comparing cohesive ability among fatty acid molecules in adsorption film by fatty acids obtained as POEs were decomposed.

• Biomolecules & Therapeutics
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• v.17 no.1
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• pp.104-110
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• 2009

Phenylketonuria (PKU) is an inherited metabolic disorder caused by mutations in the phenylalanine catabolic enzyme, phenylalanine hydroxylase (PAH). The use of phenylalanine ammonia-lase (PAL) by oral and parenteral routes as a therapeutic drug for PKU has been severely limited due to inactivation by intestinal proteolysis and immune reactions. PEGylation was applied to PAL to reduce the degrees of antigenicity and proteolytic inactivation. Kinetic experiments with native PAL and pegylated PALs were performed, and pH stability, temperature stability, and protease susceptibility were evaluated. Enzyme linked immunosorbent assay (ELISA) was carried out to measure the immune complex between pegylated PALs and antiserum that had been extracted from a PAL-immunized mouse. Pegylated PAL, especially branched pegylated PAL (10 kDa, 1:32), was more active for phenylalanine and more stable in pancreatic proteases than native PAL. Native PAL was optimal at pH 8.5, corresponding to the average pH range of the small intestine; the same finding was noted for pegylated PALs. All linear and branched pegylated PALs had low reactivity with mouse antiserum, especially the 1:16 formulation with linear 5-kDa PEG and the 1:32 formulation with branched 10-kDa PEG. Therefore, we suggest the 1:32 formulation with branched 10-kDa PEG as the most promising formulation for enzyme replacement therapy.