• 대한의생명과학회지
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• 제16권3호
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• pp.161-167
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• 2010

In this study, the biological activities of Glycyrrhiza uralensis were investigated, including antioxidative, fibrinolytic, thrombin inhibitory, and a-glucosidase inhibitory activity. The hot water extract of Glycyrrhiza uralensis was fractionated into hexane, $CHCl_3$, ethyl acetate, butanol, and water fractions, and each of these fractions were assayed individually. The water fraction showed the highest extraction yield of 19.45% (w/w). Using the DPPH method, the free radical scavenging activity was to be the strongest in the $CHCl_3$ fraction at 89.3%. Using the fibrin plate method, only the butanol fraction showed a substantial plasmin activity of 0.62 units/ml. In thrombin inhibitory activity tests, a 100-fold dilution of the ethyl acetate fraction showed the strongest activity of 46.9%. In the a-glucosidase inhibitory activity assay, a 100-fold dilution of the $CHCl_3$ fraction showed the strongest activity of 80.6%. In conclusion, the combined results of this study demonstrate that the extracts of Glycyrrhiza uralensis can be used as a material for the development of biofunctional foods for diabetics.

• 약학회지
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• 제40권6호
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• pp.653-658
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• 1996

As part of our search for less toxic antimicrobial agents from natural resources. rutin was isolated from Sophora japonica and then hydrolyzed to quercetin. Antimicrobial activity of quercetin was tested in vitro against five kinds of gram positive and ten kinds of gram negative bacteria by serial broth dilution method. Among fifteen kinds of bacteria tested, the antimicrobial activity of quercetin was the most potent against Proteus vulgaris showing minimal inhibitory concentration(MIC) of 125 ${\mu}$g/ml. To investigate the effect of antimicrobial combinations of quercetin with four kinds of antibiotics (ampicillin, cefazolin, oxytetracycline and chloramphenicol). the fractional inhibitory concentration index (FICI) was determined by checkerboard assay for each strain. The antimicrobial combinations of quercetin with four kinds of antibiotics resulted in synergism in one instance, additive effect in four instances, but no antagonism was observed.

• Toxicological Research
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• 제27권1호
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• pp.31-36
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• 2011

The methanol extract of 12 medicinal plants were evaluated for its antibacterial activity against Gram-positive (5 strains) and Gram-negative bacteria (10 strains) by assay for minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC). The antibacterial activity was determined by an agar dilution method (according to the guidelines of Clinical and Laboratory Standard Institute). All the compounds (12 extracts) of the 8 medicinal plants (leaf or root) were active against both Gram-negative and Gram-positive bacteria. Gram-negative showed a more potent action than Gram positive bacteria. The MIC concentrations were various ranged from $0.6\;{\mu}g/ml$ to $5000\;{\mu}g/ml$. The lowest MIC ($0.6\;{\mu}g/ml$) and MBC ($1.22\;{\mu}g/ml$) values were obtained with extract on 4 and 3 of the 15 microorganisms tested, respectively.

• The Plant Pathology Journal
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• 제38권6호
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• pp.616-628
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• 2022

Resistance to pyraclostrobin due to a single nucleotide polymorphism at 143rd amino acid position on the cytochrome b gene has been a major source of concern in red pepper field infected by anthracnose in Korea. Therefore, this study investigated the response of 24 isolates of C. acutatum and C. gloeosporioides isolated from anthracnose infected red pepper fruits using agar dilution method and other molecular techniques such as cytochrome b gene sequencing, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and allele-specific polymerase chain reaction (PCR). The result showed that four isolates were resistant to pyraclostrobin on agar dilution method and possessed GCT (alanine) codon at 143rd amino acid position, whereas the sensitive isolates possessed GGT (glycine). Furthermore, this study illustrated the difference in the cytochrome b gene structure of C. acutatum and C. gloeosporioides. The use of cDNA in this study suggested that the primer Cacytb-P2 can amplify the cytochrome b gene of both C. acutatum and C. gloeosporioides despite the presence of various introns in the cytochrome b gene structure of C. gloeosporioides. The use of allele-specific PCR and PCR-RFLP provided clear difference between the resistant and sensitive isolates. The application of molecular technique in the evaluation of the resistance status of anthracnose pathogen in red pepper provided rapid, reliable, and accurate results that can be helpful in the early adoption of fungicide-resistant management strategies for the strobilurins in the field.

• Bulletin of the Korean Chemical Society
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• 제26권3호
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• pp.440-446
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• 2005

A method is described for the determination of dibutyltin (DBT) in sediment by isotope dilution using liquid chromatography inductively-coupled plasma/mass spectrometry (LC-ICP/MS). To achieve the highest accuracy and precision, special attentions are paid in optimization and evaluation of overall processes of the analysis including extraction of analytes, characterization of the standards used for calibration and LC-ICP/MS conditions. An approach for characterization of natural abundance DBT standard has been developed by combining inductively-coupled plasma/optical emission spectrometry (ICP/OES) and LC-ICP/MS for the total Sn assay and the analysis of Sn species present as impurities, respectively. An excellent LC condition for separation of organotin species was found, which is suitable for simultaneous DBT and tributyltin (TBT) analysis as well as impurity analysis of DBT standards. Microwave extraction condition was also optimized for high efficiency while preventing species transformation. The present method determines the amount contents of DBT in sediments with expanded uncertainty of less than 5% and its result shows high degree of equivalence with reference values of an international inter-comparison and a certified reference material (CRM) within stated uncertainties.

• 한국식품영양과학회지
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• 제31권4호
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• pp.691-695
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• 2002

한국산 솔잎을 가압.압착하여 얻은 수액을 증류한 솔잎 수액 증류액의 각종 암세포주에 대한 in uitro 세포독성을 시료액 대비 10배, 20배, 40배 희석군과 대조군에 대해 XTT법으로 실험한 결과, 쥐 백혈병 세포주인 L1210에 대해서는 76~89%, 쥐 육종암세포인 sarcoma 180에 대해서는 61~90%의 세포성장 억제효과를 나타내었다. 또한 인체의 monocyte-like cancer cell인 U937에 대해서는 56~81%, 인체 유방암 세포주인 T47D와 MDA-MB-231에서는 각기 12%, 또 다른 유방암 세포주인 MH7A에서는 64%, 인체 간암 세포주인 SNU-354에 대해서는 72%의 높은 세포 증식 억제효과를 나타내었다. 이로써 본 연구 시료인 솔잎 수액 증류액은 쥐 백혈병 세포주인 L1210, 쥐 육종암세포인 sarcoma 180, 인체 monocyte-like cancer cell인 U937, 인체 유방암 세포주인 MH7A, 인체 간암 세포주인 SNU-354에 대해 강한 세포독성을 갖는 것을 알 수 있었다. 이와 함께 솔잎 수액 증류액의 암세포에 대한 독성효과는 솔잎의 처리과정에 따라 다를 수 있으며, 또한 동일한 솔잎 수액증류액의 농도에서도 암세포주 종류에 따라 세포독성정도가 다름을 알 수 있었다. 따라서 최적 투여 농도와 적용 암세포주를 찾을 경우 새로운 항암제로 개발될 수 있음을 제시하였다.

• BMB Reports
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• 제43권11호
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• pp.761-765
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• 2010

Salivary testosterone levels in Korean adults were quantitatively measured for the first time by liquid chromatography-electrospray-tandem mass spectrometry (LC ESI MS/MS). Salivary testosterone was separated on a multiple reaction monitoring (MRM) chromatogram within 7 min. The LC ESI MS/MS assay was validated over the linearity range of 0.01-2.00 ng/ml (r=0.99987) using testosterone-$d_3$ as an internal standard. The lower limit of quantification (LOQ) was 0.01 ng/ml. The intra- and inter-assay precisions were 1.54% to 4.09% and 0.96% to 4.29%, respectively. The mean recovery was 93.32% (range 88.43-98.05%). The validated assay was then applied to measure the salivary testosterone levels of Korean adults. In men, the salivary testosterone level collected between 9：00-11：00 am was approximately 2.8 times higher than that in women (P < 0.0001). Salivary testosterone levels in both sexes negatively correlated with age. The present assay would also be useful in measuring salivary testosterone levels in clinical laboratories.

• 한국가축번식학회지
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• 제14권1호
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• pp.31-35
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• 1990

Eosin B의 사용에 의한 rat 난모세포의 생존성 및 발달가능성을 검사하였다. 염료는 Brinster's Medium for Ovum Culture puls glucose (BMOC)-2 medium ml당 eosin B 1.0mg을 함유하는 stock solution으로 준비하였다. 난모세포연구를 위하여 BMOC로 stock solution을 희석하여 만든 3가지의 염료농도들이 선택되었다 : 0.12mM, 0.60mM, 1.20mM. 난소세포들로부터 난모세포들을 채취하고, 보존기간 및 열 처리의 다양한 조건하에서 eosin B를 사용한 dye exclusion assay로 검사하였다. 생존한 난모세포는 eosin B를 배척하고, 사멸한 세포는 eosin B를 배척하지 않는 것으로 제시되었다.

• 한국미생물·생명공학회지
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• 제46권3호
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• pp.269-276
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• 2018

Rabies virus (RABV)-specific antibodies in animals and humans are measured using standard methods such as fluorescent antibody virus neutralization (FAVN) tests and rapid fluorescent focus inhibition tests, which are based on cell culture systems. An alternative assay that is safe and easy to perform is required for rapid sero-surveillance following mass vaccination of animals. Two purified monoclonal antibodies (4G36 and B2H17) against RABV were selected as capture and detection antibodies, respectively. A genetically modified RABV, the ERAGS strain, was propagated and concentrated by polyethylene glycol precipitation. Optimal conditions for the RABV antigen, antibodies, and serum dilution for a blocking enzymelinked immune sorbent assay (B-ELISA) were established. We evaluated the sensitivity, specificity, and accuracy of the B-ELISA using serum samples from 138 dogs, 71 raccoon dogs, and 25 cats. The B-ELISA showed a diagnostic sensitivity of 95.8-96.3%, specificity of 91.3-100%, and accuracy of 96.0-97.2% compared to the FAVN test. These results suggest that the B-ELISA is useful for sero-surveillance of RABV in dogs, raccoon dogs, and cats.

• Nuclear Engineering and Technology
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• 제25권2호
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• pp.255-258
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• 1993

펄스형 질소레이저를 사용한 time-resolved laser-induced fluorimetry를 이용하여 우라늄 작업자의 뇨속에 함유되어 있는 우라늄의 농도를 간단한 전처리만으로 정량분석하는 방법을 연구하였다. 형광분석할 때에 뇨에 함유된 chloride ion은 우라늄 형광을 심하게 quenching하는 것으로 알려져 있으며, 따라서 이를 제거하기 위한 전처리 과정에서 많은 시간 소모와 큰 실험 오차를 유발하고 있다. 본 방법에서는 10% Fluran 수용액을 뇨에 첨가하여 뇨함량이 약 1% 정도가 되었을 때 뇨속의 chloride에 의한 quenching 영향을 최소한으로 줄일 수 있었으며, 시간 0에서의 형광강도를 계산하여 형광강도의 농도에 대한 직선성을 측정한 결과 우라늄 농도 범위 10-500 ppb에서 우수한 직선성을 나타내었다.