• 대한예방한의학회지
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• 제7권2호
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• pp.65-74
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• 2003

Objective : The aim of present study is to evaluate the inhibitory potential of licorice extract and glycyrrhizin on cytochrome P450(CYP) in human liver microsomes. Methods : Using human liver microsomes, water extract of licorice and glycyrrhizin as an inhibitor were co-incubated with each probe drug representing selective CYP isoform activity. We measured relative metabolic activity in incubation condition compared to that with no extract of licorice using HPLC system. Results : Both water extracts of licorice and glycyrrhizin showed inhibitory effect on CYP-catalyzed reactions. CYP2C19 $(IC_{50}=126.7{\mu}g/ml)$ is most potently inhibited by water extract than other tested CYP isoforms$(IC_{50}>450{\mu}g/ml)$, but glycyrrhizin exhibited potent inhibition on CYP1A2$(IC_{50}=106.9{\mu}g/ml)$ followed by CYP2C9 and CYP2D6. Conclusion: These results indicate that water extract of licorice and glycyrrhizin have inhibitory potential on CYP-catalyzed reaction in human liver microsomes. But the mechanism of inhibition was slightly different between them Water extract of licorice mainly inhibited CYP2C19, and glycyrrhizin primarily inhibited CYP1A2. The inhibition by water extract of licorice and glycyrrhizin on CYP isoforms may cause drug interaction with co-administered drug leading to toxicity or treatment failure.

• 한국산업융합학회 논문집
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• 제12권2호
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• pp.99-105
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• 2009

Among a few items with world wide competitiveness are the semiconductor and the LCD. Grinding/polishing is the most significant process in manufacturing semiconductor wafers and LCD panels, the most critical quality of which is the precision rate of the machined surfaces. It is well known that the control of the vibrations is the major factor in maintaining superb machined surfaces. In this paper the dynamic properties of a grinding machine have been investigated through the frequency analysis test and the computer simulation to deduce ideas of design modifications for improved stability. The alterations have been applied to the simulation model, which is supposed to have identical dynamic property with the original structure, to identify the effects and to finally achieve the satisfactory level of stability. The result shows that the machine can have much improved stability with relatively simple design changes, and also can improve the surface quality of the products.

• 식물병연구
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• 제13권2호
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• pp.93-97
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• 2007

비경작 산림 토양으로부터 고추 역병균과 탄저병균에 대한 항균활성, 불용태 인산의 가용화 및 식물체 초기생육촉진 효과를 보이는 방선균을 분리하였다. 선발된 미생물의 16S rDNA 염시서열을 분석한 결과, Streptomyces sp.로 동정되었다. Streptomyces sp. MG 121 균주는 고추열매를 이용한 역병과 탄저병을 80% 이상 억제하였다. MG 121균주 배양액의 식물체 엽면살포는 식물체의 초기생육을 10% 이상 촉진시키는 것으로 나타났다. 불용태 인산의 가용화 활성을 측정한 결과, 유리인산의 농도는 144시간 후 $762{\mu}g/ml$까지 증가하였다.

• 한국수정란이식학회지
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• 제24권2호
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• pp.89-95
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• 2009

Successful in vitro embryo production heavily relies on the normal maturation and fertilisation of oocytes. We examined the normal and abnormal fertilisation of zebu cattle oocytes matured in vitro. Immature cumulus oocyte complexes (COCs) from zebu cattle ovaries at slaughter were matured in vitro (IVM) for 24 h. The oocytes were either fixed, stained and examined for nuclear changes or fertilised in vitro (IVF) with Percoll-separated, heparintreated spermatozoa (1.0 ${\times}$ $10^6$/mL) of zebu (n = 7) and crossbred bulls (n = 7). After 18 h of sperm-COCs co-incubation at $39^{\circ}$C with 5% $CO_2$ in humidified air, the presumptive zygotes were fixed, stained and examined for pronuclei. The number of oocytes retrieved per ovary was 5.4 ${\pm}$ 0.7. The percentage of matured oocytes was 73.0. The difference in motility of spermatozoa before and after Percoll seperation was significant (p<0.001). The percentages of normal and abnormal fertilisation (polyspermia and oocytes with one pronucleus) varied significantly depending on individual bulls (p<0.05). A protocol for IVF of IVM oocytes in Bangladeshi zebu cattle is developed. A future study may elucidate the capacity of such IVM-IVF oocytes to develop to the blastocyst stage for transfer to surrogate mother.

• KSBB Journal
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• 제20권5호
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• pp.345-349
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• 2005

본 연구에서는 악취 분해 균주를 분리하기 위하여 광주시 소재 전자공장 등의 하천 및 주변토양 및 울산, 온산, 여천 공업단지의 오염토양 및 슬러지 등으로부터 분리한 균주들 중 악취제거용 균주를 Pseudomonas sp. TKC를 분리$\cdot$동정하였다. 분리 균주의 증식의 최적조건은 초기 기질농도 500 ppm, 배양온도 $30^{\circ}C$, 초기 pH 7, 혼합속도 150rpm, 그리고 $(NH_4)_2SO_4$ 3.0 g/l를 포함하는 MSM 배지로 설정하였다.

• 한국미생물·생명공학회지
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• 제38권4호
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• pp.385-390
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• 2010

청국장의 기호도를 개선하는 발효균으로 분리된 protease 생산균은 Bacillus licheniformis로 확인되었다. Protease 생산을 위한 배지를 최적화하기 위한 탄소원, 질소원, 인, 금속이온의 성분을 변화시키면서 균의 성장과 효소 생산성을 비교하였다. Glucose를 탄소원으로 사용하였을 때는 균의 성장은 정상적으로 일어나지만, protease 생산이 심하게 억제되는 것으로 나타났으며, Potato starch를 탄소원으로 사용하였을 때 효소 생산성이 가장 높았다. 질소원으로는 yeast extact가 효소 생산에 가장 적합하였다. 한편 2가 금속이온중 $Zn^{2+}$, $Cu^{2+}$, $Co^{2+}$을 배지에 첨가하였을 때는 균의 성장이 심하게 저해되었으며, 효소 생산도 되지 않았다. $CaCl_2$를 첨가한 배지에서는 균이 성장과 효소 생산성이 증가되었다. Potato starch(1.5%), yeast extract(1.5%), $CaCl_2$(0.7%), $K_2HPO_4$(0.03%)와 $KH_2PO_4$(0.03%)를 포함하는 것으로 구성된 최적화 배지에서 최대효소 생산성은 800 U/mL로 나타났으며 28시간 이후에는 배양액내 효소활성이 서서히 감소하였다.

• 대한의생명과학회지
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• 제25권4호
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• pp.431-435
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• 2019

Chlorine dioxide is an effective chemical to inhibit the growth of bacteria and viruses or to disinfect infected areas. In this study, the effects of chlorine dioxide on several bacteria in hospitals were analyzed. Alloiococcus otitis, Kocuria rosea, Leuconostoc mesenteroides spp. and Staphylococcus lentus as gram-positive bacteria and Acinetobacter lwoffii, Aeromonas salmonicida, Brucella melitensis, Oligella ureolytica as gram-negative bacteria were done for the inhibitory analysis. The growth and morphology of the bacteria were analyzed by placing a plastic stick which was called "FarmeTok (medistick/Puristic)" provided by Purgofarm, co, Ltd. to release ClO₂ (13 ppmv/hr) next to the plate where the bacteria were incubated for 24 hours. Less than 10 bacterial colonies were evaluated as having 99% inhibitory effect. The initial bacterial culture concentration of 0.5 McFaland turbidity was good for analyzing the chlorine dioxide inhibitory effect. All bacteria could be easily counted post 24 hr co-incubation with ClO₂, but A. otitis and A. lwoffii without ClO₂ gas were not countable due to very dispersed colony types which were not affected for result analysis. As shown in this study, the FarmeTok plastic stick, which discharges chlorine dioxide at 13 ppmv / hour, was evaluated to be sufficient to suppress the above bacteria in the hospital. Bacteria existing in the clinic such as this hospital will be used as a data to inhibit the growth of bacteria by using ClO₂, and molecular biology analysis using the gene of bacteria will be possible in the future rather than inhibiting the growth of bacteria itself.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권2호
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• pp.47-54
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• 2015

The objective of this study was to optimize the experimental conditions for bioleaching of arsenic (As) using Herbaspirillum sp. GW103 and to understand the interaction between bacteria and As during bioleaching. Five variables, temperature, time, CaCO₃, coconut oil cake, and shaking rate, were optimized using response surface methodology (RSM) based Box-Behnken design (BBD). Maximum (73.2%) bioleaching of As was observed at 30℃, 60 h incubation, 1.75% CaCO₃, 3% coconut oil cake, and 140 rpm. Sequential extraction of bioleached soil revealed that the isolate Herbaspirillum sp. GW103 significantly reduced 28.6% of water soluble fraction and increased 38.8% of the carbonate fraction. The results of the study indicate that the diazotrophic bacteria Herbaspirillum sp. could be used for bioleaching As from mine soil.

• Journal of Korean Neurosurgical Society
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• 제38권6호
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• pp.456-464
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• 2005

Objective : The authors investigated whether rotenone induces cellular death also in non-dopaminergic neurons and high concentration of potassium ion can show protective effect for non-dopaminergic neuron in case of rotenone-induced cytotoxicity. Methods : Neuro 2A cells was treated with rotenone, and their survival as well as cell death mechanism was estimated using 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium[MTT] assay, Lactate dehydrogenase[LDH] release assay, fluorescence microscopy, and agarose gel electrophoresis. The changes in rotenone-treated cells was also studied after co-treatment of 50mM KCl. And the protective effect of KCl was evaluated by mitochondrial membrane potential assay and compared with the effects of various antioxidants. Results : Neuro 2A cells treated with rotenone underwent apoptotic death showing chromosome condensation and fragmentation as well as DNA laddering. Co-incubation of neuro 2A cells with 50mM KCl prevented it from the cytotoxicity induced by rotenone. Intracellular accumulation of reactive oxygen species[ROS] resulting by rotenone were significantly reduced by 50mM KCl. Potassium exhibited significantly similar potency compared to the antioxidants. Conclusion : The present findings showed that potassium attenuated rotenone-induced cytotoxicity, intracellular accumulation of ROS, and fragmentation of DNA in Neuro 2A cells. These findings suggest the therapeutic potential of potassium ion in neuronal apoptosis, but the practical application of high concentration of potassium ion remains to be settled.

• 약학회지
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• 제38권5호
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• pp.614-620
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• 1994

Following the study on the fermentation conditions influencing the production of vitamin $B_{12}$ by Propionibacterium shermanii(Korean J Biotechnol. Bioeng. 7,126-131, 1992), the effects of some factors supplemented in the medium on the production of vitamin $B_{12}$ were studied. Maximum production of vitamin $B_{12}$ was observed when $Co^{+2}$ was supplemented at the concentration of 2-4 ppm in the fermentation medium. Increase of the supplemented $Co^{+2}$ to 12 ppm did not inhibit the growth of the organism, but it accelerated the lysis of the organism. In the literature, peptone was reported to activate the biosynthesis of vitamin $B_{12}$. Examination of the effect of peptone on the growth and the production of vitamin $B_{12}$ showed that at early stage more vitamin$B_{12}$ was observed in the supplemented medium, but no difference was observed in the later stage of fermentation. Examination of the time for addition and the amount of 5,6-dimethylbenzimidazole, a precursor known to influence the production of vitamin $B_{12}$, showed that a maximum yield of vitamin $B_{12}$ was observed when 15 mg/L was added to the fermentation medium after 2 days' incubation. The effect was comparable with the increase of the production of vitamin $B_{12}$ when the fermentation condition was changed to aerobic condition after 2 days' culture under anaerobic condition.