• Food Science and Preservation
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• v.8 no.1
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• pp.92-101
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• 2001

In order to develop the Production and application of cholesterol oxidase, a cholesterol degradation bacteria which produces a remarkable amount of extracellular cholesterol oxidase has been isolated from Korea traditional salt fermented flat fish. The isolated strain was identified as a strain of Bacil1us sp. based on its morphological, physiological characteristics and cellular fatty acid compositions. Experiments were carried out to optimize the condition of cholesterol oxidase production using Bacillus sp. SFF34. Bacillus sp. SFF34 was shown to give the maximum yield of cholesterol oxidase in the medium containing 2.0% glucose, 0.5% yeast extract, 0.02% MgSO$_4$$.$7H$_2$O, 0.025% K$_2$HPO$_4$, 0.15% NH$_4$NO$_3$ and 0.2% cholesterol. The optimum culture conditions, temperature, initial pH and agitation speed were 30$^{\circ}C$, 7.0 and 150rpm respectively. The enzyme production reached a maximum level at 24 hrs of cultivation(2.42 U/ml).

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.4
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• pp.348-357
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• 1988

The present work was undertaken to investigated the purification and characterization of polyphenol oxidase (PPO ; EC 1.10.3.1) in sweet potato, particularly the number of PPO isozymes, and PPO properties such as pH optimum, heat stability, substrate specificity, kinetics, and inhibitor studies. The purification achieved was 23.1 fold from crude extract with a yield of 41.5%. Eight PPO isozymes and twelve PPO isozymes were detected by disc polyacrylamide gel electrophoresis and isoelectric focusing, respectively. The specific activity of each isozyme separated by isoelectric focusing was in the range of $6,000{\sim}46,700U/mg$. This enzyme was sweet below $65^{\circ}C$ and the pH optimum of PPO occurred at 6.0-6.5. The substrate specificity of sweet potato PPO showed the high affinity toward the odiphenolic compounds. Km and Vmax for catechol were found to be 6.7 mM and $20{\triangle}A/min$, me protein, respectively. Inhibitor studies indicated that dithiothreitol was the most potent among the inhibitors used in the present work.

• Journal of environmental and Sanitary engineering
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• v.12 no.1
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• pp.15-23
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• 1997

The anionic exchange resins with the Dowex-1 and Amberlite CG-400 form were transformed into resin of sulfate and acetate acid form, respectively. The uranyl complex ions with SO$_{4}$$^{2-}$ and CH$_{3}$COO$^{-}$ were adsorbed on the anion exchange resion mentioned above, and these complex ions were eluted as mixture eluents of 0.7M HNO$_{3}$ - 0.5M NH$_{4}$NO$_{3}$ by anion exchange chromatography. The optimum adsorption conditions of uranyl anion complex ions adsorbed on the upper of the resin colmun were 1.5-2.0 ml/min of flow rates at pH 2.0 and adsorptive power of uranyl complex ion of sulfuric acid type were nearly consistent with the Caussion normal distribution curve, whereas the elution state of UO$_{2}$(Ac)$_{2}$$^{4-}$ with acetic acid type was departed. The weighing form obtained from resin of sulfuric acid and aceric acid type was U$_{3}$O$_{8}$ whose recovery was 91.7%. The possibility of recovering uranium from the monazite sulfate solution using a strong base anion resin, Amberlite CG-400(sulfate form), was successfully recovered more than 90%.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.11
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• pp.1412-1420
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• 2010

In this study, changes in testicular tissues of rats subjected to xylene and formaldehyde inhalation were evaluated. Three experimental groups were included in the study. Each group of rats was exposed to formaldehyde (6 ppm), technical xylene (300 ppm) or a combination of these two agents (150 ppm+3 ppm) for 8 weeks (8 h/d). Control groups were maintained for a period of eight weeks under the same conditions. Staining methods (triple staining, strep ABC method) were applied to examine histometric changes and relaxin like factor (RLF) expression in the testicular tissue. Immunostaining for RLF showed that density of staining for RLF decreased in rats exposed to formaldehyde. Formaldehyde or a combination of formaldehyde and xylene led to a decrease in seminiferous epithelial height. In conclusion, exposure of rats to formaldehyde and xylene-formaldehyde combinations adversely affects Leydig cells (RLF) and seminiferous epithelium of testicular tissue.

• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.413-420
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• 2003

A gas chromatography/mass spectrometric assay method was developed for the simultaneous determination of neutral and bacis twenty-five disruptors $(ED_S)$ in frog and fish. Afther homogenization and sonication of 5 g of sample, purification was achieves in one step with a solid phase extraction procedure using silica gelflorisl. Eluton was performed with 50mL of acetone : n-hexane (1 : 9) solution. The eluate was concentrated to approximately 10uL and dissolves with 100 uL of hexane and analyzed by GC-MS (SIM). The peaks had good chromatographic properties and the extraction of these compounds from sample also gave relatively high recoveries with small variatoins. Detection limits were 0.1 ng/g for 4-nitrotoluene, benzophenone, hexachlorobenzene, atrazine, malathion, o,p-DDT, o,p-DDT and permethrin, and 0.2 ng/g for heptachlor epoxide, γ-chlordane, α-chlordane, p,p'-DDE, p,p'-DDD, cypermethrin and fenvalerate, and 0.3 ng/g for trifluralin, metribuzin, alachlor, dieldrin and p,p'-DDT, and 0.5 ng/g for heptachlor, aldrin and parathion, and 0.7 ng/g for endrin, and 0.8 ng/g for nitrofen. The recoveries were between 33 and 109%. The method was used to analyze twenty-five frogs and forty-six fishes fishes samples caught from various regions in Korea. Benzophenone was detected at concentration of up to 17.2 ng/g in frog or fish. Heptachlor, aldrin, γ-chlordane, p,p'-DDE, p,p'-DDD, endrin and o,p-DDD were detected at concentrations of 0.7-12.5 ng/g in frog or fish. Also significant leveles of dieldrin (up to 22.5 ng/g) were observed. The developed method may be valuable to be used to the national monitoring project of EDS in biota samples.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.8
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• pp.175-197
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• 2003

Die vorligende Arbeit behandelt die Probleme der $Koh\"{a}renz$ und Interpretation von van de Velde unter einigen Gesichtspunkten, welche mit der Frage $zusammenh\"{a}ngen$: Wie wird Sprachverstehen $erm\"{o}glicht$? Nach van de Velde besteht der wissen­schaftliche Zugang zu den Sprachverstehensprozessen und Interpretationsstrategien darin, dass man Erkenntnisse $\"{u}ber$ ihre bedingenden Faktoren gewinnt Seine Arbeit versucht diese bedingenden Faktoren in folgenden Gegebenheiten aufzufinden: 1) in den innersprachlichen Gegebenheiten, 2) in den $Referenzzusammenh\"{a}ngen$, auf die sich innersprachliche Gegebenheiten beziehen, 3) in den Handlungskontexten, in denen die verwendeten Sprachgegebenheiten ihre Funktionen haben, 4) in den zwischenmenschlichen $Kormnunikationsrahmenverh\"{a}lnissen$, 5) in den kognitiven Prozessen des Sprachrezipienten, in der neuro(psycho)logischen Ausstattung des Sprachbenutzers. Genau gesagt, bleiben die folgenden Fragen trotzdem immer nur offen: 1) Kann jede Ebene $f\"{u}r$ die $Koh\"{a}renz$ bei van de Velde in der Wirklichkeit schon da sein? 2) Sind die Wertigkeiten jeder Ebenen gleich? 3) Muss die $Koh\"{a}renz$ zwischen Inferenz und Verstehen sein? 4) Gibt es irgendeine Einheitstheorie, solche $interdisziplin\"{a}re$ Faktoren zu beherrschen?

• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.804-810
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• 2003

The fine powder produced by heating and grinding of the waste concrete in the waste construction was investigated whether utilize as substitution raw material of SiO$_2$, CaO, and Al$_2$O$_3$ source for OPC clinker manufacture is possible or not. In order to synthesize OPC clinker, limestone, shale, converter slag and fly ash were used as main raw materials, and modulus was fixed LSF 91.0, SM 2.60, IM 1.60. The synthesized clinkers were characterized. The Main products of synthesized clinker were C$_3$S, ${\beta}$-C$_2$S, C$_3$A, C$_4$AF as OPC clinker at 1,43$^{\circ}C$. As a result of TG-DTA and burnability index(B.U) analysis of each raw mixtures, the formation temperature of clinker phases was similar and B.I was showed easy burning as 48.6∼51.4.

• The Korean Journal of Pharmacology
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• v.24 no.2
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• pp.221-232
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• 1988

Studies were conducted to determine whether reduced renal blood flow (RBF) exhibited by rats with uncontrolled, streptozotocin (STZ)-induced diabetes is attributable to diabetes-associated, enhanced renal vasoconstrictor influence of endogenous thromboxane $(TX)A_2$. Rats which were injected with STZ after pretreatment with 3-O-methyl glucose (3OMG), an agent which prevents STZ-induced hyperglycemia, were also studied. Basal values of total RBF (RBF; ml $min^{-1}$ $gKw^{-1}$; electromagnetic flow probe), systemic arterial pressure (BP; mm Hg) and renal vascular resistance (RVR;BP $RBF^{-1})$in pentobarbital-anesthetized rats during a control period were $5.9{\pm}0.3$(P<0.1_{VS}. CR), $115{\pm}3$ and $20.3{\pm}1.0$(P<0.1_{VS}. CR) for STZR (n=15), and $8.4{\pm}0.4$, $123{\pm}3$ and $15.1{\pm}0.8$ for age-matched control rats (CR; n= 15), respectively. Basal values of RBF, BP and RVR in 3OMG pretreated STZR were identical to CR. In preparations shown capable of renal vasodilatation, OKY 1581 (1 mg/kg, i.v. followed by 0.4 mg/kg min infusion) abolished arachidonate-induced $(TX)A_2$ synthesis, but did not alter basal BP, RBF or RVR in either STZR or CR (n=4/group). Similarly, i.r.a. infusion of SQ29548 (100 ng/ml RBF) abolished renal vasoconstriction induced by a TX/prostaglandin endoperoxide mimic, U46619, but had no discern able affect on RVR in either STZR (n=8) or CR (n=8). The data indicates that $TXA_2$ does not participate in the elevated basal RVR of STZR which are associated with the diabetic state.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.12
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• pp.1582-1582
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• 2000

Rayleigh scattering and laser induced predissociative fluorescence are employed for capturing two-dimensional images of temperature and species concentration in a laminar nonpremixed flame of a diluted hydrogen jet. Rayleigh scattering cross-sections are experimentally obtained at 248nm. Dispersed LIPF spectra of OH and O₂ are also measured in a flame in order to confirm the excitation of single vibronic state of OH and O₂are excited on the P₁(8) line of the A ²∑+ (v＇=3) - X ²∏(v˝=0) band and R(17) line of the Schumann-Runge band B ³∑u- (v＇=0) - X ³∑g-∏(v˝=6), respectively. Fluorescence spectra of OH and Hot O₂ are captured and two-dimensional images of the hydrogen flame field are successfully visualized.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.5
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• pp.325-332
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• 2000

To determine the distribution and recovery of fall-applied N in various parts of satsuma mandarins (Citrus unshiu Marc). $19.68g\;N\;tree^{-1}$ as urea containing 5 atom % $^{15}N$ and 58 kg$K_2O$ $ha^{-1}$ were broadcast-applied to 11 years old 'Miyagawa Wase' grown at a spacing of $2.7{\times}2.7m$ on 18 November 1998. Nitrogen, $P_2O_5$, and $K_2O$ were applied at 104, 308, and $62kg\;ha^{-1}$ on 22 March and N and $K_2O$ at 42 and $83kg\;ha^{-1}$ on 15 June 1999. Two trees were excavated on 15 June and 8 December 1999, respectively. In mid-June, whole tree contained $168.2g\;N\;tree^{-1}$ of which 11.9, 42.1, 29.7, and 16.3% were in fruits, leaves, stems, and roots, respectively. In early December, total tree N averaged $169.8g\;tree^{-1}$ and fruits accounted for 27.6%, leaves 36.4%, stems 22.8%, and roots 13.2% of total tree N. Regardless of harvest date, N derived from fertilizer was highest in newly developed tissues. In mid June, the tree recovered 18.5% ($3.63g\;tree^{-1}$) of fertilizer N. Fruits accounted for 21.1%, leaves for 50.4%, stems for 21.5%, and roots for 7.9% of fertilizer-derived N in the tree, respectively. In early December, the tree recovered 17.0% of fertilizer N. Fruits contained 39.6%, leaves 40.5%, stems 14.5%, and roots 5.3% of fertilizer-derived N in the tree respectively. Comparing with total tree N, a higher proportion of fertilizer-derived N was allocated to metabolically active tissues while a less proportion to old tissues regardless of harvest date.