• 미생물학회지
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• 제18권1호
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• pp.7-14
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• 1980

A thermostrable ${\beta}-galactosidase$ (${\beta}-galactoside$ galactohydorlase, EC 3.2.1.23) was inducible in Bacillus coagulans by lactose and D-glactose. The enzyme was purified 87 fold, and the optimum temeprature and pH for actiivity were determined to be $60^{\circ}C$ and pH 7.5, respectively. Kinetic determinations at $55^{\circ}C$ established a Km of 3.3mM for the chromogenic substrate onitorphenyl ${\beta}-D-galactopyranoside$ (ONPG). Galactose and lactose were competitive inhibitors with Ki of 6.1mM and 4.9mM, respectively. The enzyme ws relatively thermostable. The crude enzyme was inactivated about 20% after 20 min of exposure at $60^{\circ}C$ and the purified was about 50%. Maximal enzyme activity required $Mn^{++}$, and for the thermal stabilization $Fe^{++}\;and\;Ca^{++}$ were necessary.

• 한국염색가공학회지
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• 제25권1호
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• pp.13-17
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• 2013

A new assembly derived from 2,3-dibromo-5,6,7,8-tetrafluoroquinizarin and sodium diethyl-carbamodithiolate, was prepared as an efficient $Fe^{3+}$ colorimetric chemosensor with high selectivity over other cations $Fe^{3+}$, $Na^+$, $Mg^{2+}$, $Pb^{2+}$, $Cd^{2+}$, $Ni^{2+}$, $Ca^{2+}$, $Cu^{2+}$, $Hg^{2+}$, $Zn^{2+}$ : from the dark blue to brown color change that is visible by eyes. This assembly produced large bathochromic shift of 228 nm in the presence of $Fe^{3+}$ compared with the corresponding absorption maximum of the parent dye.

• 한국미생물·생명공학회지
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• 제23권1호
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• pp.53-59
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• 1995

A protease isolated and purified 51 fold from the culture filtrate of a soil bacterium, Bacillus sp. KUN-17, which was appeared to be a monomeric protein with molecular weight of 38, 000 daltons, was suggested to be involved in the serine (-alkaline) protease (E.C 3.4.21.14) since its activity was selectively inhibited by phenylmethylsulfonyl fluoride (PMSF) and required 40$\circ$C and pH 10.5 for optimal condition. The half-life of the enzyme activity was 1 hr at 55$\circ$C, and the activity was maintained even under high concentrations of SDS or urea. The enzyme was indicated to perform random proteolysis from the fact that most of the chromogenic substrates employed were hydrolyzed by the enzyme. The affinity of the enzyme for natural proteins was approximately 10-times higher than ester compounds, and both substrates showed mutual inhibitory effect competitively for the enzyme activity.

• Journal of Nutrition and Health
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• 제15권1호
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• pp.30-38
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• 1982

Experiments were carried out in order to compare the natural antioxidants in the acetonitril extracts of raw and baked seeds of Korean sesame and perilla by thin layer and gas chromatography. The sample was dissolved in n-pentane and extracted with acetonitril and the acetonitril extract was separated by thin layer chromatography using silica gel. The spots were detected by spraying with 2, 6 -dichloroquinone -4-chlorimide, phosphomolybdic acid and dimethylamine as chromogenic reagents. Natural antioxidant, such as ${\delta}-tocopherol$ detected in raw and baked sesame and perilla seed oil by TLC and sesamol was detected only in raw and baked sesame seed oil by GC.

• 한국수의병리학회:학술대회논문집
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• 한국수의병리학회 2003년도 추계학술대회초록집
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• pp.40-40
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• 2003

The c-erbB2/neu oncogene (alias HER2, NEU) encoding a tyrosine kinase receptor protein, the overexpression of which correlates with a more rapid progression and a worse prognosis in human breast cancer [1]. Otherwise, this gene is still poorly investigated in veterinary oncology [2,3]. To gain insight into the patterns of c-erbB2/neu status in canine mammary tumor, we constructed one such mammary tumor tissue microarray (TMA) from 60 tumors from our lab. This enabled the amplification of c-erbB2/neu oncogene of all 60 tumors to be simultaneously analyzed by chromogenic in situ hybridization (CISH). The aim of this study was to evaluate status of c-erbB2/neu oncogene in canine mammary tumors and to correlate this status with the differentiation grade of neoplasm. (omitted)

• Food Science and Biotechnology
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• 제14권6호
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• pp.875-877
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• 2005

Presence of Enterobacter sakazakii, occasional pathogen of powdered infant formula causing rare, but life-threatening diseases such as neonatal meningitis, bacteremia, necrotizing enterocolitis, and necrotizing meningoencephalitis after ingestion was examined in 45 powdered infant formula products manufactured in Korea using chromogenic Druggan-Forsythe-Iversen (DFI) medium, and isolates were identified with API 20E. Ent. sakazakii was isolated from three products. Ent. sakazakii isolates were genotyped by RAPD-PCR using two random primers, and their banding patterns were compared.

• 분석과학
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• 제8권4호
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• pp.469-475
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• 1995

Di-2-pyridylmethanon 2-thiophenecarboxylie hydrazone(DPMTCH) was synthesized and used as a chromogenic reagent in the spectrophotometric determination of nickel in steel. The proton disc spectrophotometrically, were $pK_{a1}= 2.66$ and $pK_{a2}= 10.98$ ${\mu}=0.5(NaCl)$. Nickel(II) reacts with DPMTCH to form a 1:2 metal-2-ligand ratio complex, the xylene solution of which has an absorption maximum at 417 nm. Beer's law is obeyed over the range $0-1.17\;mg\;ml^{-1}$ of nickel(II). The molar absorptivity of the nickel(II) complex is $4.17{\times}10^4l\;mol^{-1}\;cm^{-1}$. The precision of the method was estimated for 4.7 mg of nickel(II), the coefficient of variation for 15 replicate determinations being 0.34%.

• 대한약학회:학술대회논문집
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• 대한약학회 2001년도 Proceedings of International Convention of the Pharmaceutical Society of Korea
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• pp.285.2-286
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• 2001

• 한국임상수의학회지
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• 제15권1호
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• pp.228-233
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• 1998

Incidence of gastrointestinal disease in dogs of Seoul and Kyung-gi area was 40.5% (380/939) and dogs with gastrointestinal disease were more likely to be 1-5 month old (55.5%). Comparison among seasons revealed that spring(48.3%) was potentially at increased risk The incidence of pancreatitis in the gastrointestinal disease was 1.49% (6/402). In helathy dogs, amylase activity was higher in male dogs than female and in the alee of >1 year than <1 year. Lipase activity was higher in female dogs than male, and higher in the age of <1 year than >1 year. The correlation coefficient$(r^{2})$ was 0.71 between the methods of measuring amylase; amyloclastic and chromogenic methods.

• Bulletin of the Korean Chemical Society
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• 제18권1호
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• pp.44-50
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• 1997

A method of dual-signal generation from two different enzymes was developed and utilized to simultaneously perform dual immunoassays in a single microwell. Two enzymes selected as tracers were horseradish peroxidase (HRP) and β-galactosidase (GAL). 3, 3', 5, 5'-Tetramethylbenzidine (TMB) and chlorophenolred-β-galactopyranoside (CPRG) as chromogenic substrates for the respective enzyme were used. Although the two enzymes showed their maximum activities at distinct pH conditions (pH 5.1 for HRP and 7.5 for GAL), the enzyme reactions were able to be concurrently carried out at pH 5.75 in a dual-substrate solution without signal loss. This performance was achieved by increasing TMB concentration two-fold, introducing potassium salt as activator of GAL reaction, and extending total reaction time 50%. The signal generation method was then used for dual-enzyme immunoassays to detect antibodies with co-immobilized Hepatitis C virus antigens (core and NS5) and a Hepatitis B virus antigen (PreS(2)) in a microwell. Dose-response curves of the assays revealed cooperativity between different antigen-antibody complex formation, which suggested that dual immunoassays can only be used for qualitative screening tests unless the antigens immobilized were spatially separated.