• Food Science and Biotechnology
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• 제18권4호
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• pp.861-866
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• 2009

Effects of pressure come-up and holding times on the inactivation of Salmonella enterica and Listeria monocytogenes were evaluated in deionized water, milk, orange juice, and tomato juice with pH 6.76, 6.85, 3.46, and 4.11, respectively. The inoculated samples were subjected to high pressure treatments at 300, 400, and 500 MPa for less than 10 min at $30^{\circ}C$. At 500 MPa, the numbers of S. enterica and L. monocytogenes in deionized water, orange juice, and tomato juice were reduced by more than 6 log CFU/mL during the come-up time. Compared to orange and tomato juices, milk showed a considerable baroprotective effect against S. enterica and L. monocytogenes. At 300 MPa, the D values for S. enterica in milk, orange juice, and tomato juice were 0.94, 0.41, and 0.45 min, while those for L. monocytogenes were 9.56, 1.11, and 0.94 min, respectively. Low pH resulted in a noticeable synergistic effect on the inactivation of S. enterica and L. monocytogenes in orange and tomato juices. Therefore, these results might provide more useful information for designing the entire high hydrostatic pressure (HHP) conditions, taking the come-up time reduction, and food system.

• 한국미생물·생명공학회지
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• 제19권3호
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• pp.296-302
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• 1991

소나무 숲 토양에서 방선균을 666주 선별한 후 이중 glucose isomerase 생산성이 우수하고 (488U/ml) 40 포도당액의 이성화율이 5%3에 도달하는 TH34 균주를 선별하였다. 이 균주는 세포벽을 구성하는 diaminopimelic acid(DAP), 기균사의 색깔, spiral type의 spore 사슬의 형태, melanoid 색소형성, 탄수화물 이용성 및 전자현미경 사진등으로 미루어 보아 Streptomyces luteogriseus로 동정하였다. 분리 동정한 S.luteogriseus의 발효조건 및 배지조성 등을 검토하여 본 결과 28~$29^{\circ}C$에서 효소생산이 최대이었으며 pH 6.0~8.0의 넓은 범위에서 안정한 효소생산을 보였다.

• 응용통계연구
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• 제35권3호
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• pp.347-356
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• 2022

본 논문에서는 금융 시계열 비대칭 변동성을 모형화하기 위해서 다중 임계점을 가진 비대칭-ARCH 점화식(A-ARCH(1))을 제안하고 있다. 특히 임계점이 두 개인 간단한 모형에 초점을 맞추어 설명하고 있으며 미국 S&P500 자료 분석을 통해 예시하였다. 다양한 A-ARCH(1) 모형의 예측력 비교를 위해 모수적-붓스트랩을 활용하여 예측오차의 평가 및 예측구간의 정확도를 설명하였다.

• 한국양식학회지
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• 제17권4호
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• pp.268-274
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• 2004

본 연구에서는 넙치, Paralichthys olivaceus를 이용하여 oxytetracycline (OTC)처리농도에 따른 체내에서 혈액 생리학적인 변화, 항산화 효소 및 열충격단백질(HSP)등의 변화를 조사하여 항생제의 안정적인 사용에 대한 기초 자료를 제공하고자 본 실험을 수행하였다. 실험구는 각각 0 (대조구), 100, 300 및 500ppm으로 설정하였으며, 1시간 약욕처리 후 순환시켜 0, 1 및 3시간 후에 혈액성상을 분석하였다. 혈액 중 hematocrit(Ht)수치는 전 실험구에서 감소하는 경향을 보였으나 유의한 차이는 나타나지 않았다. Red blood cell (RBC)는 농도 의존적으로 감소하는 경향을 나타내었다. 또한, 혈청 글루코오스 농도는 농도 의존적으로 증가되는 경향을 나타내었으나, 노출 이후 3시간 경과 후에는 이전 대조구 수준으로 감소되었다. 혈중 단백질량은 0시간째 전 실험구에서 감소되었다가 이후 증가하는 경향을 나타내었으나, 처리전의 대조구와 비교하여 유의하게 낮은 값을 나타내었다. SOD 효소 활성은 노출 직후 300 및 500ppm에서는 유의하게 높은 값을 나타내었다. CAT효소활성은 OTC처리 농도에 비례하여 감소하는 경향을 보였으나 유의한 차이는 나타내지 않았다. 그리고 HSP-70의 단백질량은 100 ppm및 500 ppm처리구에서 대조구에 비해 높게 발현되는 것이 확인되었다. 그러나 HSP-70 mRNA는 다소 증가하는 경향은 보였으나, 모든 실험구에서 유의한 차이는 나타나지 않았다.

• 아시안잔디학회지
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• 제10권2호
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• pp.159-166
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• 1996

To estimate removal rate of phosphorus in aquatic grassland ecosystems of Paldangho, this investigation was conducted along with the coast of a lake. The experimental results may be summarized on communities of Typha angustata, Miscanthus sacchriflorus Phragmites communis and Scirpus tabernaemontani as follows. The annual production of phosphorus for the litters in T. angustata, M saccharsflorus, P. cam-munis and S. taiernaemontani grasslands were 10.252 g /$m^2$, 3.833 g /$m^2$, , 2.656 g /$m^2$, and 5.210 g /$m^2$, respectively. The ratio of annual production of P accumulated on surface soils in a steady state provides estimates of the removal rate r, The estimated removal rates r of P were 0.58, 0.78, 0.68 and 0.59 in T. angustata, M. sacchariflorus, P. communis and S. tabernaemontani grasslands re- spectively. The removal and accumulation of 50, 95 and of 99% of its steady state level, the estimates for P of T. angustata were 1.195, 5.173 and 8.623 years, in M. sacchariflorus were 0.880, 3.842, and 6.403 years, and in P. cammunis were 1.014, 4.390, and 7.316 years respectively, In S. tabernaemontani grassland required period were 1.178,5.099 and 8.500. Key words:T. angustata, S. tabernaemantani, P. communis, S. tabernaemontani, Paldangho, Removal rate, Phosphorus.

• Archives of Pharmacal Research
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• 제24권2호
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• pp.159-163
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• 2001

The accelerated stability of dimethoxy biphenyl monocarboxylate.HCl (DDB-S) was investigated in 6 mg/mL water solution in the pH ranging 2-10 and the temperature of $45-85^{\circ}C$. The observed rate of degradation followed first-order kinetics. The energy of activation for DDB-S degradation was calculated to be 14.1 and 16.5 $Kcal/mole$ at pH 5 and in distilled watery respectively. The degradation rate constant ($K_{25^{\circ}C}$) obtained by trending line analysis of Arrhenius plots for DDB-S was $5.3{\times}10^{-6}h^{-1}$. The times to degrade 10% ($t_{10}$) and 50% $t_{500}$) at $K_{25^{\circ}C}$ were 829 and 5,416 days, respectively. DDB-S exhibited the fastest degradation at pH 10 and the slowest rate at pH 5. In addition, at $K_{65^{\circ}C}$, degradation rate constants of DDB-S were 0.066, 0.059, 5.460, 32.171, and $1.4{\times}10^{-6}h^{-1}$ at pH 2, 5, 8, 10 and in distilled water, respectively. These observations indicated that the rate-pH profile of DDB-S showed general acid-base catalysis reaction in the range of pH 2-10.

• 대한본초학회지
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• 제24권1호
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• pp.179-189
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• 2009

Objectives : Coptidis Rhizoma (Coptis japonica MAKINO; CR) is a well known crude drug as antimicrobial, antibacterial, anti-inflammatory, antioxidant activity. However, there is no study of the effect of CR on brain infarction and it's mechanism. The aim of this study was to investigate the effects on ischemic stroke induced by photothrombotic infarction by evaluating the functional & neuronal recovery after brain infarction. Materials & Methods : Male Sprague-Dawley rats (250-300 g) were induced photothrombotic brain infarction on sensorimotor cortex, and brain infarction volume by image J software (NIH, USA) after Nissl stain, also single pellet reaching task as a functional motor recovery were observed. After orally pretreated by CR (500 mg/kg) or normal saline as a sham control before 7 days from the time of photothrombotic infarction, rats were sacrificed. After then we analysed anti-inflammatory cytokines (TNF-$\alpha$, IL-6, IL-1$\beta$), by RT-PCR and ELISA method, and immunohistochemistry (GFAP, connexin-43) as a marker of neural plasticity. Results : CR (100, 250, 500 mg/kg) decreased the infarction volume dose-dependently, however the effect of 500mg/kg of CR (CR 500) showed the best (P=0.051). Also, CR 500 decreased the infarction volume time-dependently, the most effective time was 3-7 days after stroke. Photothrombosis increased inflammatory cytokines after infarction, CR 500 suppressed significantly mRNA expression of IL-1$\beta$, IL-6 and TNF-$\alpha$. In serum, CR 500 decreased the amount of IL-1$\beta$, 12h, 24h and 48h respectively (p < 0.05), also decreased that of IL-6 and TNF-$\alpha$, 12h respectively (p < 0.05) after infarction. The more astrocytes were observed and neural plasticity was facilitated in the rat brain of CR 500 than that of sham control in immunohistochemistry. Conclusions : This results suggest that CR decrease infarction volume and improve functional motor recovery in acute stage in photothrombotic ischemic infarction model in the mechanism of anti-inflammation and promoting neural plasticity.

• 생명과학회지
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• 제12권6호
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• pp.803-811
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• 2002

초석잠 헥산 추출물이 식중독균에 대한 천연 항균 활성 가능성을 검토하였다. 초석잠 헥산 추출물의 항균 작용을 알아보기 위하여 공시 균주인 Bacillus cereus, Staphylococcus aureus, E, coli 및 Listeria monocytogenes등에 대하여 disc법으로 실험한 결과 그람음성 및 그람 양성균에 대하여 15~20 mm의 clear zone이 나타났다. 초석잠 헥산 추출물의 MIC는 Bacillus cereus에 대해 250${\mu}g$/$m\ell$ Listeria monocytogenes에 대해 250~500/$m\ell$그리고 Staphylococcus aureua와 Pseudomonoas aeruginosa에 대해 각각 500${\mu}g$/$m\ell$ 나타내었다. 초석잠 추출물을 처리한 전자현미경(TEM)상에서는 처리균주들의 세포막이 파괴되어 세포내용물이 용출된 것을 볼 수 있었다. 초석잠 추출물을 처리한 균주의 세포막 손상의 정도를 알아보기 위하여 균체내 효소인 $\beta$-galactosidase 활성을 측정한 결과 클로로포름보다 세포막을 더 손상시키는 것이 확인되었다. 그리고 초석잠 추출물의 pH 및 열 안정성을 실험한 결과 매우 안정하였다.

• 한국작물학회지
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• 제38권3호
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• pp.275-282
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• 1993

본 연구는 한국 옥수수의 $\alpha$-amylase의 유전자 클로닝을 주된 목표로 하여 수행되었다. 이를 위하여 여러 식물체의 $\alpha$-amylase 염기서열로 부터 잘 보존된 부분을 참고로 oligonucleotlde probe 및 PCR primer를 설계, 합성하고, 옥수수의 유묘로부터 전체 RNA를 분리하여 northern blot analysis를 통하여 확인한 다음, 이로부터 첫 번째 가닥 cDNA를 만든 후, 여기서 얻은 RNA : DNA hybrid를 주형으로 한 polymerase chain reaction을 통하여 길이 가 약 500bp되 는 PCR 산물을 얻었다. 이를 클로닝하기 위해 pUC19을 클로닝 백터로 사용하여 재조합 플라스미드인 $\ulcorner$pZM$\alpha$'$\lrcorner$를 만들었다. 합성 probe를 이용, Southern blot analysis한 결과, $\ulcorner$pZM$\alpha$'$\lrcorner$가 옥수수 mRNA로 부터 증폭된 DNA의 일부분을 갖고 있음을 확인하였으며, 그 길이는 PCR 산물과 같은 500bp가량 되는 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권12호
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• pp.1716-1721
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• 2006

The present study was conducted to observe the effect of osmolality of glycerolated TEST-yolk glycerol extenders on post-thawing sperm kinematics of ram spermatozoa of the native Malpura breed maintained in a semi-arid tropical environment. Good quality semen obtained from adult rams was pooled, split and diluted to 1,000 million spermatozoa per ml in complete TEST-yolk-glycerol extenders of 900, 1,200, 1,500 and 1,800 mOsm/kg osmolality. Diluted semen samples were loaded in 0.25 ml straws and cooled down to $-125^{\circ}C$ freezing temperature at the rate of $-25^{\circ}C$ per minute under controlled conditions before plunging into liquid nitrogen for storage. The thawing of straws was performed at $50^{\circ}C$ in a water bath for 10 seconds and sperm kinematics of the frozen-thawed spermatozoa were assessed by a computer-assisted sperm analysis technique. Osmolality of diluent had no significant effect on post-thawing % motility, % rapid, % medium and % slow moving frozen-thawed spermatozoa but significantly (p< 0.05) affected the % linearity and % straightness. The post-thawing % motility and % rapid motile spermatozoa were highest in samples extended in diluent of 1,500 mOsm/kg osmolality and lowest in 900 mOsm/kg. The curvilinear velocity of spermatozoa was significantly (p<0.05) higher for samples extended in 1,800 mOsm/kg, compared to those in 900 and 1,200 mOsm/kg, but the effect was not significantly different to those extended in diluent of 1,500 mOsm/kg osmolality. The study indicated that ram spermatozoa could tolerate a wide osmolality range for dilution in the complete TEST-yolk-glycerol extender for their cryosurvival. The highest recovery of motile spermatozoa following thawing was achieved in samples extended in the TEST-yolk-glycerol diluent of 1,500 mOsm/kg osmolality.