• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.230-237
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• 2004

In this study nitroreductase from Pseudomonas sp. HK-6 capable of degrading 2,4,6-trinitrotoluene (TNT) was characterized. Through a series of purification process including ammonium sulfate precipitation, DEAE-sepharose, and Q-sepharose, three different fractions I, II, and III having the enzyme activity of NTRs whose molecular weights were approximately 27 kDa were detected in fractions from HK-6 cells. Specific activity of the three fractions were approximately 4.85 unit/mg, 5.47 unit/mg, and 5.01 unit/mg, and concentrated to 9.0-, 10.1-, and 9.3-fold compared to crude extract, respectively. The optimal pH and temperature for the three NTR fractions were approximately 7.5 and $30^{\circ}C$, respectively. Metal ions, $Ag^{＋}$ , $Cu^{ 2+}$, $Hg^{2＋}$ inhibited approximately 70% of enzymes activities of all NTR, while $Fe^{2＋}$ did not stimulate or inhibit the activities. Monitoring the effect of chemicals on the enzyme activity revealed that those NTR fractions lost enzyme activity in presence of $\beta$-mercaptoethanol, but were a little influenced by dithiothreitol, EDTA and NaCl. The three NTR fractions demonstrated enzyme activities for nitrobenzene and RDX as well as TNT.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.356-364
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• 2009

The current ruminant feeding models require parameterization of the digestion kinetics of carbohydrate fractions in feed ingredients to estimate the supply of nutrients from a ration. Using an automated gas production technique, statistically welldefined digestion rate of carbohydrate, including soluble carbohydrate, can be estimated in a relatively easy way. In this study, the gas production during in vitro fermentation was measured and recorded by an automated gas production system to investigate degradation kinetics of carbohydrate fractions of a wide range of ruminant feeds: corn silage, rice straw, corn, soybean hull, soybean meal, and cell mass from lysine production (CMLP). The gas production from un-fractionated, ethanol insoluble residue and neutral detergent insoluble residue of the feed samples were obtained. The gas profiles of carbohydrate fractions on the basis of the carbohydrate scheme of the Cornell Net Carbohydrate and Protein System (A, B1, B2, B3 and C) were generated using a subtraction approach. After the gas profiles were plotted with time, a curve was fitted with a single-pool exponential equation with a discrete lag to obtain kinetic parameters that can be used as inputs for modern nutritional models. The fractional degradation rate constants (Kd) of corn silage were 11.6, 25.7, 14.8 and 0.8%/h for un-fractioned, A, B1 and B2 fractions, respectively. The values were statistically well estimated, assessed by high t-value (>12.9). The Kd of carbohydrate fractions in rice straw were 4.8, 21.1, 5.7 and 0.5%/h for un-fractioned, A, B1 and B2 fractions, respectively. Although the Kd of B2 fraction was poorly defined with a t-value of 4.4, the Kd of the other fractions showed tvalues higher than 21.9. The un-fractioned corn showed the highest Kd (18.2%/h) among the feeds tested, and the Kd of A plus B1 fraction was 18.7%/h. Soybean hull had a Kd of 6.0, 29.0, 3.8 and 13.8%/h for un-fractioned, A, B1 and B2, respectively. The large Kd of fraction B2 indicated that NDF in soybean hull was easily degradable. The t-values were higher than 20 except for the B1 fraction (5.7). The estimated Kd of soybean meal was 9.6, 24.3, 5.0%/h for un-fractioned, A and B1 fractions, respectively. A small amount of gas (5.6 ml at 48 ho of incubation) was produced from fermentation of CMLP which contained little carbohydrate. In summary, the automated gas production system was satisfactory for the estimation of well defined (t-value >12) kinetic parameters and Kd of soluble carbohydrate fractions of various feedstuffs that supply mainly carbohydrate. The subtraction approach, however, should be applied with caution for some concentrates, especially those which contain a high level of crude protein since nitrogen-containing compounds can interfere with gas production.

• Korean journal of food and cookery science
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• v.20 no.2
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• pp.204-210
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• 2004

This study was performed to provide basic physiological activities data to predict the usefulness of olive leaves as a food material. Total flavonoid and total phenol contents of 80% ethanol extract of olive leaf were 5.81% and 14.8%, respectively. Total flavonoid and total phenol contents were markedly higher in butanol and ethyl acetate fractions than in hexane, chloroform, and water fractions (p＜0.05). Oleuropein in olive leaf was the major phenolic compound. The oleuropein contents of 80% ethanol extract, butanol and ethyl acetate fractions of olive leaf were 102.11${\pm}$0.02, 173.35${\pm}$0.03 and 152.71${\pm}$0.03 mg/100g, respectively. The 80% ethanol extract, butanol and ethyl acetate fractions of olive leaf showed a growth inhibitory effect to Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella enteritidis, whereas antimicrobial activities of hexane and chloroform fractions were not observed. The inhibitory activity to ACE was determined to be very weekly positive in 80% ethanol extract and all fractions of olive leaf. The nitrite-scavenging ability of 80% ethanol extract, butanol and ethyl acetate fractions of olive leaf were 72.8%, 76.0% and 75.4%, respectively. Significant evidence was detected that the butanol and ethyl acetate fractions showed higher activity than that of hexane, chloroform, and water fractions (p＜0.05).

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.438-443
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• 2017

The biological activity of crude polyphenol fractions (WphF, EphE, VphF, and SphF) extracted from Cedrela sinensis using hot water, ethanol, and enzymes such as Viscozyme and Shearzyme was examined in this study. The yield of VphF was the highest (43.44%) among all fractions. The total polyphenol and flavonoid content of the fractions were highest after ethanol extraction (447.98 and 337.49 mg/g, respectively). Fractions obtained after hot water and ethanol treatment showed high antioxidant activity. All fractions, except for WphF, showed a significantly higher ${\alpha}$-glucosidase inhibitory activity than the acarbose. EphF and WphF showed the high acetylcholinesterase inhibition activity. All fractions showed more than 50% tyrosinase inhibition activity at 2 mg/mL concentration. According to these results, the crude polyphenol fractions from C. sinensis showed high antioxidative, ${\alpha}$-glucosidase inhibitory, and tyrosinase inhibitory activities. This study suggests that crude polyphenol fractions from C. sinensis, especially the WphF and EphF fractions, are good sources of functional food.

• Education of Primary School Mathematics
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• v.26 no.3
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• pp.181-197
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• 2023

The importance of reasoning processes based on fractional concepts and number senses, rather than a formalized procedural method using common denominators, has been noted in a number of studies in relation to compare the magnitudes of unlike fractions. In this study, a unlike fraction magnitudes comparison test was conducted on fourth-grade elementary school students who did not learn equivalent fractions and common denominators to analyze the reasoning perspectives of the correct and wrong answers for each of the eight problem types. As a result of the analysis, even students before learning equivalent fractions and reduction to common denominators were able to compare the unlike fractions through reasoning based on fractional sense. The perspective chosen by the most students for the comparison of the magnitudes of unlike fractions is the 'part-whole perspective', which shows that reasoning when comparing the magnitudes of fractions depends heavily on the concept of fractions itself. In addition, it was found that students who lack a conceptual understanding of fractions led to difficulties in having quantitative sense of fraction, making it difficult to compare and infer the magnitudes of unlike fractions. Based on the results of the study, some didactical implications were derived for reasoning guidance based on the concept of fractions and the sense of numbers without reduction to common denominators when comparing the magnitudes of unlike fraction.

• Journal of Educational Research in Mathematics
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• v.26 no.4
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• pp.663-682
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• 2016

This study conducted an analysis of strategies that the 3rd to 6th grade elementary students used when they were solving problems of comparing the size of the fractions with like and unlike denominators, and unit fractions. Although there were slight differences in the students' use of strategies according to the problem types, students were found to use the 'part-whole strategy', 'transforming strategy', and 'between fractions strategy' frequently. But 'pieces strategy', 'unit fraction strategy', 'within fraction strategy', and 'equivalent fraction strategy' were not used frequently. In regard to the strategy use that is appropriate to the problem condition, it was found that students needed to use the 'unit fraction strategy', and the 'within fraction strategy', whereas there were many errors in their use of the 'between fractions strategy'. Based on the results, the study attempted to provide pedagogical implications in teaching and learning for comparing the size of the fractions.

• Journal of Sericultural and Entomological Science
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• v.13 no.2
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• pp.141-143
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• 1971

By means of thin-layer electrophoresis in agarose gel, hemolymph protein of healthy silkworm larvae and of the nuclear polygedrosis virus infected larvae were studied. 1. In the 4th instar, 4 fractions moving toward anode were separated. Dye-binding Capacity of the fraction was increased according to the stage. 2. After 5th day in the 5th instar, 7 fractions moving toward anode were separated, and one fraction toward cathode was separated. 3. On the first day in the 5th instar, 5 fractions were separated, and on the 4th day of the same instar 5 fractions were separated. 4. As for the hemolymph protein fractions of the polyhedrosis virus infected larvae, on the 6th and 7th day, three fractions(D.E.F) were inclined to increase, whereas on the 8th day 4 fractions(A.B.D.E) were disappeared but F fraction was inclined to decrease.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.8
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• pp.649-654
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• 2009

Respirometric analysis of domestic sewage by measuring oxygen uptake rate(OUR) was carried out for the experimental assessment of the organic and biomass fractions. The data of the organic and biomass fractions in sewage is essential for the activated sludge model to optimize the biological treatment plant. As a result of this study, the fractions of readily biodegradable substrate($S_S$), slowly biodegradable substrate($X_S$), inert soluble substrate($S_I$), inert particular substrate($X_I$) and heterotrophic biomass($X_{HAB}$) were about 26.6%, 41.5%, 8.5%, 14.7% and 8.7% on the basis of chemical oxygen demand($COD_{Cr}$), respectively. And the fractions of nitrogen were also studied. The fractions of soluble nitrate nitrogen($S_{NO}$), soluble ammonia nitrogen($S_{NH}$), soluble nonbiodegradable organic nitrogen($S_{NI}$), soluble biodegradable organic nitrogen($S_{ND}$) and slowly biodegradable organic nitrogen($X_{ND}$) were about 3.7%, 64.9%, 4.7%, 9.4% and 17.4%, respectively.

• Korean Journal of Medicinal Crop Science
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• v.28 no.1
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• pp.29-37
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• 2020

Background: Although Gastrodia elata contains the valuable, bio-active compounds gastrodin and 4-hydroxybenzyl alcohol (4-HBA), it also contain ρ-cresol, which is a major source of an objectionable pig slurry-like odor. Accordingly, this study was performed to determine the deodorization effect of Diaion HP-20 resin on a G. elata extract. Methods and Results: Using Diaion HP-20 with an increasing concentration of ethanol, an extract of G. elata was fractionated into 15 fractions, which were anlayzed to determine their concentrations of active compounds and ρ-cresol. The gastrodin, 4-HBA, total phenolics, and ρ-cresol concentrations of the G. elata extract were 403.13, 408.15, 2,476.09, and 11.77 ㎍/㎖, respectively. Among the different fractions, gastrodin and 4-HBA were detected in fractions 3 to- 6, and 4 to- 10, respectively whereas total phenolics were detected in all samples, with fractions 5 to- 7 being characterized by higher concentrations than were the other fractions. ρ-Cresol was detected in fractions 12 to- 15, at concentrations ranging from 0.39 ㎍/㎖ to 6.05 ㎍/㎖ with the highest concentration detected in fraction 14. The fractions containing ρ-cresol could be selectively separated from the G. elata extract without the loss of major bio-active compounds such as gastrodin and 4-HBA. Conclusions: The results of this study indicate that a deodorizing method using Diaion HP-20 resin can be considered for improving the sensory qualities of G. elata extract without a loss of the major bio-active compounds.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.975-979
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• 2006

The extracts of Oenanthe javanica were evaluated for their effects on the expression of cyclooxygenase-2 (COX-2), which is mediated by the translocation of the p65 subunit into the nucleus. Fractions of ethyl acetate and chloroform from 80% ethanol extracts of O. javanica exhibited inhibitory effects on the secretion of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) from lipopolysaccharide (LPS)-stimulated peritoneal macrophages; however, the aqueous- and hexane-fractions showed no significant effect. The ethyl acetate- and chloroform-fractions also reduced the COX-2 enzyme levels after 24-hr treatment. RT-PCR showed that the mRNA levels of COX-2 decreased following treatment with these fractions, suggesting that COX-2 expression is transcriptionally regulated by these extracts. We examined the effects of the chloroform- and ethyl acetate-fractions on the cytosolic activation of nuclear factor-${\kappa}B$ ($NF-{\kappa}B$, p65 subunit) and on the degradation of inhibitor-${\kappa}B{\alpha}$ ($I-{\kappa}B{\alpha}$) in order to determine the mechanism of COX-2 regulation. The LPS-stimulated activation of the p65 subunit was significantly blocked upon the addition of $50\;{\mu}g/mL$ of these fractions, and the cytosolic $I-{\kappa}B{\alpha}$ degradation process was simultaneously inhibited. These findings suggest that the inhibition of COX-2 expression by the ethyl acetate-and chloroform-fractions may result from the inhibition of p65 translocation by blocking the degradation of $I-{\kappa}B{\alpha}$; this may be the mechanistic basis for the anti-inflammatory effects of O. javanica.