• 생명과학회지
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• 제20권2호
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• pp.260-268
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• 2010

가물치(Channa argus) 조직의 젖산탈수소효소 동위효소(EC 1.1.1.27, lactate dehydrogenase, LDH)를 정제하고 생화학적, 면역학적 및 역학적 방법으로 특성을 연구하였다. LDH 활성은 골격근이 380.4 units로 가장 높고 심장 13.4, 눈 3.5, 뇌 조직 5.4 units이었으며, 심장의 CS 활성은 20.7 unit로 가장 높고, LDH/CS는 골격근 172.9, 심장 0.6, 눈 0.32, 뇌 0.47이고, 단백질 양은 골격근 14.7 mg/g이며, 특이활성(units/mg)은 골격근 25.88, 심장 0.79, 눈 0.31, 뇌 1.38 units/mg이었으므로 골격근은 혐기적이고, 심장은 호기적이었다. LDH $A_4$, $B_4$, eye-specific $C_4$에 대한 항혈청을 사용한 Western blot, 면역침강반응 및 native-polyacrylamide gel electrophoresis에 의해 $A_4$, $A_3B$, $A_2B_2$, $AB_3$ 및 $B_4$가 모든 조직에서 확인되었고, 눈 조직에서 $C_4$와 $AC_3$, $A_2C_2$, $AC_3$, 뇌 조직에서 $A_3C$도 확인되었다. LDH $A_4$, $A_3B$, $A_2B_2$, $AB_3$, $B_4$, eye-specific $C_4$ 동위효소는 affinity chromatography와 Preparative PAGE Cell에 의해 정제되었다. LDH $A_4$ 동위효소는 $NAD^+$ 유입 후 정제되었고, eye-specific $C_4$는 $A_4$에 이어 용출되기 시작하였으며 $B_4$는 buffer 유입 후 용출되었다. 정제한 결과 $A_4$는 $B_4$ 및 eye-specific $C_4$와 분자구조의 일부가 유사하였지만 $B_4$와 $C_4$는 서로 다른 것으로 나타났으므로, 하부단위체 A는 보존적이고, 하부단위체 B는 A보다 더 빠르게 진화된 것으로 보인다. 피루브산 10 mM에서 $A_4$ 동위효소 39.98%, $A_2B_2$ 21.28%, $B_4$ 19.67% 및 eye-specific $C_4$ 16.87%의 활성이 남아있었고, 피루브산에 대한 $Km^{PYR}$은 $A_4$ 0.17 mM, $B_4$ 0.27 mM, eye-specific $C_4$ 0.133 mM였다. $A_4$, $B_4$, eye-specific $C_4$, $A_2B_2$, $A_3B$ 및 $AB_3$의 최적 pH는 각각 pH 6.50, pH 8.5, pH 5.5, pH 6.0-6.5, 5.0 및 pH 7.5였고, 동질사량체 $A_4$와 이질사량체 동위효소들은 넓은 pH 영역에서 안정하였다. 특히 골격근은 LDH 활성이 크므로 활동성이 크며, 눈조직에서 피루브산 친화력이 강한 eye-specific $C_4$에 의해 피루브산 대사가 빠르게 일어나고, 이어서 $A_4$에 의해 젖산이 산화되어지는 것으로 사료되므로, 종의 생태환경 및 먹이 획득 양식에 따라 LDH-C 발현, 기질에 대한 친화도 및 대사 시간이 다른 것으로 사료된다.

• KSBB Journal
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• 제15권4호
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• pp.359-365
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• 2000

Three lactic acid bacteria (C-1 K-3 and T-1 strain) were isolated from Nuruk and characterized subsequently. They were useful strains for production of lactic acid and their growth was inhibited at 10% ethanol pH 4 These strains were identified as lactococcus lactis subsp. lactis NR C-1 Leuconostoc mesenteroides subsp. mesenterides NR K-3 and pediococcus pentosaceus NR T-1 respectively by morphological physiological and biochemical characterization Lac lactis subsp lactis NR C-1 showed the highest lactic acid productivity. Leu measenteroides subsp mesenteroides NR K-3 showed stable lactic acid productivity and its growth was inhibited at pH 4. P pentosaceus NR T-1 had lower lactic acid productivity than the other two bacteria but it could not grow at 10% ethanol pH 4 The lactic acid productivity of these three strains in MRS broth were higher than that in Skim milk media the optimum pH and temperature for the lactic acid production of the three strains were 30-32$^{\circ}C$ and pH 6.0∼6.8 Glucose was the optimal carbon souorce for the lactic acid production. In terms of antagonism lac lactis subsp lactis NR c-1 showed somewhat inhibitory efects against some Gram positive rod and cocci such as Lactobacillus brevis and Streptococcus mitis. And Leu mesenteroides subsp mesenteroides NR K-3 showed the inhibitory effects against Streptococcus mitis but P. pentosaceus NR T-1 didn't show any inhibitory effects against tested strains.

• Applied Biological Chemistry
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• 제36권5호
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• pp.370-375
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• 1993

벼잎의 산성 buffer(pH 2.8) 추출 조효소는 5개의 전기영동 band들이 PR protein으로 알려진 chitinase와 ${\beta}-1,3-glucanase$의 효소활성을 보유하고 있는 것으로 나타났다. 조효소는 DEAE-cellulose 및 chitin affinity chromatography로 염기성 및 산성 효소군으로 분획되었으며, 이들은 두 효소활성이외에도 lysozyme 활성을 보유하고 있었다. 분자량이 $14.3{\sim}66.0\;kd$ 범위인 이 두 효소군이 보유한 각 효소활성의 최적 pH와 온도를 조사해본 결과,${\beta}-1,3-glucanase$는 각각 pH 5와 $60^{\circ}C$로 동일하였으나, chitinase는 염기성 효소군에서 pH 4와 $50^{\circ}C$, 산성 효소군에서는 pH 3와 $60^{\circ}C$으로 다르게 나타나서, 전기영동 양상과 더불어 서로 상이한 효소분획인 것으로 추정되었다.

• 한국미생물·생명공학회지
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• 제2권3호
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• pp.133-140
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• 1974

1. 고온성 사상균인 Myriococcum albomyces의 밀기울 액체배양액에는 xylanase 활성이 있다. 2. Xylanase의 최적 pH는 5.0이었다. 그리고 xylanase의 pH 안정범위는 pH 4.0~7.0 이었다. 3. Xylanase의 최적온도는 5$0^{\circ}C$ 이었다. 4. Xylanase의 열안정성은 $65^{\circ}C$에서 65분간 안전하였다. 5. 액체 배양약은 SE-Sephadex, DEAE-Sepadex 및 Sephadex G-100 column chronatography 로 2종의 xylanase(A. B)를 분리하였다. 6. 정제 xylanase A는 액화형의 xylanase이고 정제 xylanase B는 당화형의 xylanase이었다. 7. 정제 xylanase A의 최적 pH는 4.0, pH 안정성 3.0~8.0 온도안정성은 7$0^{\circ}C$에서 60분간이었고 정제 xylanase B의 최적 pH 5.0 pH, 안정성 4.0~8.5 온도 안정성은 $65^{\circ}C$에서 60분간이었다.

• 대한치과보철학회지
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• 제35권2호
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• pp.385-399
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• 1997

The purpose of this experiment was to determine the effects of etching with a Nd : YAG Laser on dentin, or porcelain surface on the bond strength with composite resin. The dentin specimens were devided into the following 4 groups. D1 : No treatment D2 : Etched with 10% phosphoric acid D3 : Laser etchded with 1W, 20PPs D4 : Laser etched with 2W, 20PPS The procelain specimens were devided into the following 4 groups. P1 : diamond roughened P2 : etched with HF acid P3 : Laser etched with 2W, 20PPS P4 : Laser etched with 3W, 20PPS All specimens were veneered with resin. One half of the specimens were stored in $37^{\circ}C$ water for one day and the other half were thermocycled 1000 times at temperature of $5^{\circ}C\;to\;55^{\circ}C$ at 20 seconds intervals. After that, the bonding strength of composite resin to the dentin and porcelain was measured. The surface treated state and fractured state were observed with SEM. The following results were obtained. 1. In the dentin specimens, the bond strength of group D2 was highter than that of groups D1 and D3 in the case of the specimens stored in $37^{\circ}C$ water for one day, there was a statistically significant difference between group D2 and D1, D3 (P<0.05). The bonding strength of the specimens that were thermocycled decreased in the following order : group D2,D4,D3 and then D1. 2. In the porcelain specimens, the bonding strength of groups P1,P2 were higher than that of group P3 in the case of the specimens stored in $37^{\circ}C$ water for one day (P<0.05). The bonding strength of the specimens of being thermocycled decreased in the following order : group P2,P1,P4 and then P3. 3. The groups of high bond strength had a rougher surface and a high level of microporosity with SEM findings.

• Applied Biological Chemistry
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• 제38권3호
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• pp.248-253
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• 1995

참깨박 단백질의 기능개선을 위한 가수분해 조건을 검토한 결과 분리된 참깨박단백질에 대한 각 효소의 최적작용조건은 papain의 경우 pH 6.0, $60^{\circ}C$,효소 대 기질의 비는 기질량에 대해 3%, 기질농도 1.5%에서 최적이었으며, pepsin은 pH 2.0, $50{\sim}60^{\circ}C$, 효소의 농도는 기질량에 대해 3%, 기질농도 1%에서 최적이었다. 그리고 trypsin은 pH 9.0, $60^{\circ}C$, 효소의 농도는 기질량에 대해 1%, 기질의 농도 1%에서 가장 높은 효소작용을 보였다.

• 한국식품영양과학회지
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• 제35권2호
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• pp.212-218
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• 2006

독화된 진주담치 (blue mussel, Mylilus edulis)를 pH 처리, 온도별 저장 그리고 가열에 의한 마비성 패류독의 독성과 독조성 특성 변화는 다음과 같다. pH 3으로 조절한 시료가 14.1 MU/g$(100\%)$으로 가장 높은 독성이 검출되었고, pH 5는 12.9 MU/g$(92.1\%)$, pH 7은 9.0 MU/g$(63.8\%)$으로 검출되었으나, 마비성 패류독은 독성이 불안정한 알칼리 조건인 pH 9에서는 3.6 Mu/g$(25.5\%)$, pH 10은 0.8 Mu/g$(5.7\%)$으로 독성 이 검출되었다. 저장기간 동안의 독성은 pH(3, 5, 7, 9) 그리고 온도(30, -5, $20^{\circ}C$)에서 5일$(19.9\~65.3\%)$까지 현저하게 감소하였으나, 5일 후부터 30일까지는 약간의 독성이 감소하였다. 그리고 더 높은 온도에서 저장에서는 독성이 더 빨리 감소하였다. 대부분의 성분인 C군(C1, C2)과 GTX1,2,3,4, STX 그리고 dcSTX으로 8개의 성분이 검출되었고, 8개의 독성분 중에서 GTX1,4, STX 그리고 dcSTX는 모든 가공 조건에서 독성이 감소함에 따라 제일 먼저 감소하였다. 독성이 기준 독성치(4 MU/g)보다 3배 이상이더라도 마쇄된 패류 육에 pH를 알칼리 (pH 7이상)로 처리하고, 10분의 가열에 의해 독성을 완전히 제거할 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제22권1호
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• pp.82-89
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• 2009

Two in vitro experiments were conducted to examine the effects of propionate precursors in the dicarboxylic acid pathway on ruminal fermentatation characteristics, $CH_4$ production and degradation of feed by rumen microbes. Fumarate or malate as sodium salts (Exp. 1) or acid type (Exp. 2) were added to the culture solution (150 ml, 50% strained rumen fluid and 50% artificial saliva) to achieve final concentrations of 0, 8, 16 and 24 mM, and incubated anaerobically for 0, 1, 3, 6, 9 and 12 h at $39^{\circ}C$. For both experiments, two grams of feed consisting of 70% concentrate and 30% ground alfalfa (DM basis) were prepared in a nylon bag, and were placed in a bottle containing the culture solution. Addition of fumarate or malate in both sodium salt and acid form increased (p<0.0001) pH of culture solution at 3, 6, 9 and 12 h incubations. The pH (p<0.0001) and total volatile fatty acids (VFA, p<0.05) were enhanced by these precursors as sodium salt at 3, 6 and 9 h incubations, and pH (p<0.001) and total VFA (p<0.01) from fumarate or malate in acid form were enhanced at a late stage of fermentation (9 h and 12 h) as the addition level increased. pH was higher (p<0.001) for fumarate than for malate as sodium salt at 3 h and 6 h incubations. Propionate ($C_3$) proportion was increased (p<0.0001) but those of $C_2$ (p<0.05) and $C_4$ (p<0.01 - p<0.001) were reduced by the addition of sodium salt precursors from 3 h to 12 incubation times while both precursors in acid form enhanced (p<0.011 - p<0.0001) proportion of $C_3$ from 6h but reduced (p<0.018 - p<0.0005) $C_4$ proportion at incubation times of 1, 3, 9 and 12 h. Proportion of $C_3$ was increased (p<0.05 - p<0.0001) at all incubation times by both precursors as sodium salt while that of $C_3$ was increased (p<0.001) from 6h but $C_4$ proportion was decreased by both precursors in acid form as the addition level increased. Proportion of $C_3$ was higher (p<0.01 - p<0.001) for fumarate than malate as sodium salt from 6 h incubation but was higher for malate than fumarate in acid form at 9 h (p<0.05) and 12 h (p<0.01) incubation times. Increased levels (16 and 24 mM) of fumarate or malate as sodium salt (p<0.017) and both precursors in acid form (p<0.028) increased the total gas production, but no differences were found between precursors in both chemical types. Propionate precursors in both chemical types clearly reduced (p<0.0001 - p<0.0002) $CH_4$ production, and the reduction (p<0.001 - p<0.0001) was dose dependent as the addition level of precursors increased. The $CH_4$ generated was smaller (p<0.01 - p<0.0001) for fumarate than for malate in both chemical types. Addition of fumarate or malate as sodium type reduced (p<0.004) dry matter degradation while both precursors in both chemical types slightly increased neutral detergent fiber degradability of feed in the nylon bag.

• 대한수학회논문집
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• 제20권3호
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• pp.467-485
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• 2005

Let p and q be odd primes with p=2q+1. We study the number of solutions of congruence equations $ax^i\;+\;by^j\;{\equiv}\;c$ (mod p) and a$ax^i\;+\;by^j\;+\;dz^t\;{\equiv}\;c(modp)$

• 한국응용과학기술학회지
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• 제9권2호
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• pp.149-156
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• 1992

Levels of total lipids in the seeds of three species of the Pinaceae family were determined and their fatty acid compositions were also analyzed by a gas-chromatograph equipped with a capillary column coated with Carbowax 20M. The results are summarized as follows: Lipid contents of the seeds amounted to 56.9% in P. koraiensis, 29.9% in P. thunbergii, and 21.2% in P. rigida. In all lipids 19${\sim}$20 fatty acid were detected and, surprisingly, fatty acids having ${\Delta}^5$-non-methylene interrupted conjugate double bond such as ${\Delta}^{5, 9}-C_{18:2},{\Delta}^{5, 9, 12}-C_{18:3}\;and\;{\Delta}^{5, 11, 14}-C_{20:3}$ occurred in appreciable amounts. In the lipids of P. koraiensis, the main component was $C_{18:2}{\omega}_6(45.0%)$, followed by $C_18:1{\omega} _9(26.9%)$ and ${\Delta}^{5, 9, 12}-C_{18:3}(14.6%)$, and then ${\Delta}^{5, 9}-C_{18:2}(2.2%)$ and ${\Delta}^{5, 11, 14}-C_{20:3}$ were also present. Levels of saturated fatty acid such as $C_{16:0}\;and\;C_{18:0}$ were as low as 7.5%. The seed oil of P. thunbergii predominantly comprised $C_{18:2}{\omega}_6(45.2%)$, and was then occupied by equal amounts ${\Delta}^{5, 9, 12}-C_{18:3}(18.1%)$ and $C_{18:1}{\omega}_9(18.1%)$. Its ${\Delta}^5, 11, 14}-C_{20:3}(5.8%)$ level was the highest in the samples tested. ${\Delta}^{5, 9}-C_{18:2}(2.8%)$ was also detected with other minor components. In the oils from the seeds of P. rigida, $C_{18:2}{\omega}_6$ was present as a main component, accompanied by $C_{18:1}{\omega}_9(21.6%)$ and ${\Delta}^{5, 9, 12}-C_{18:3}(20.3%)$. The latter showed higher level than in any other samples. A minor component corresponding to ${\Delta}^{5, 9, 12, 15}-C_{18:4}$(not confirmed by GC-Mass) occurred in P. thunbergii and P. rigida.