• 한국미생물·생명공학회지
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• 제23권2호
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• pp.214-219
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• 1995

In fermentation of dairy products, bifidobacteria is used in conjunction with other lactic acid bacteria, such as L. acidophilus, L. bulgaricus and S. thermophilus, rendering the enumeration of bifidobacteria difficult. In order to develop optimum conditions for selective enumeration of bifidobacteria, we examined MIC of several antibiotics against various bifidobacteria and other lactic acid bacteria. The growth of L. acidophilus, L. bulgaricus and S. thermophilus were inhibited by lithium chloride at the concentration of less than 4 mg/ml, whereas growth inhibition of bifidobacteria occurred at concentrations over 6-10 mg/ml. Tetracycline and chloramphenicol were also found to selectively inhibit growth of other lactic acid bacteria at the concentration of 1-3 $\mu$g/ml. Addition of 6 mg/ml lithium chloride, 1 $\mu$g/ml, tetracycline or 3 $\mu$g/ml chloramphenicol to medium was found to be optimal for selective enumeration of bifidobacteria. By using these three inhibitory chemicals in the TPY medium, higher number of bifidobacteria were selectively isolated than with NPNL agar and LP agar.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1744-1749
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• 2010

The role of endophytic fungi in plant growth and development is well documented. However, endophytic fungi with growth promotion capacity have never been isolated from weeds previously. In the current study, we isolated 8 fungal endophytes from the roots of Monochoria vaginalis, a serious weed of rice paddy in Korea. These isolates were screened on Waito-C, in order to identify plant growth promoting metabolites. Two fungal isolates (M5.A & M1.5) significantly promoted the plant height and shoot length of Waito-C during preliminary screening experiments. The culture filtrates (CFs) of M5.A and M1.5 also promoted the shoot length of Echinocloa crusgalli. Gibberellins (GAs) analysis of the CFs of M5.A and M1.5 showed that these endophytic fungi secrete higher quantities of GAs as compared with wild-type G. fujikuroi KCCM12329. The CF of M5.A contained bioactive GAs ($GA_3$, 2.8 ng/ml; $GA_4$, 2.6 ng/ml, and $GA_7$, 6.68 ng/ml) in conjunction with physiologically inactive $GA_9$ (1.61 ng/ml) and $GA_{24}$ (0.18 ng/ml). The CF of M1.5 contained physiologically active GAs ($GA_3$, 1.64 ng/ml; $GA_4$, 1.37 ng/ml and $GA_7$, 6.29 ng/ml) in conjunction with physiologically inactive $GA_9$ (3.44 ng/ml), $GA_{12}$ (0.3 ng/ml), and $GA_{24}$ (0.59 ng/ml). M5.A and M1.5 were identified as new strains of Penicillium sp. and Aspergillus sp., respectively, based on their 18S rDNA sequence homology and phylogenetic analysis.

• KSBB Journal
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• 제23권4호
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• pp.297-302
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• 2008

오죽으로부터 HPLC On-line $ABTS^{+}$ screening기법을 사용하여 Flavone C-glycosides의 특성중의 하나인 항산화활성을 빠르게 분석하였으며, 오죽으로부터 homoorientin와 orientin의 추출을 다양한 초음파 주파수와 시간의 추출방법을 적용하였다. 전처리한 추출액에 포함된 오죽의 Flavone C-glycosides을 분석하고 최적의 추출조건을 실험적으로 모색하였다. 실험결과에 의하면 전체 수율에서는 Frequency 72 KHz, 60분에서 3.37 mg으로 추출 효율이 높았고, homoorientin와 orientin의 항산화활성은 Frequency 35 KHz, 30분으로 추출한 시료가 73.8%와 14.8%로 가장 우수하였다.

• 한국안전학회지
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• 제21권3호
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• pp.137-142
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• 2006

Quantification of error possibility, in an HRA process, should be performed so that the result of the qualitative analysis can be utilized in other areas in conjunction with overall safety estimation results. And also, the quantification is an essential process to analyze the error possibility in detail and to obtain countermeasures for the errors through screening procedures. In previous studies for the quantification of error possibility, nominal values were assigned by the experts' judgements and utilized as corresponding probabilities. The values assigned by experts' experiences and judgements, however, require verifications on their reliability. In this study, the validity of new error possibility values in new MCR design was verified by using the Onisawa's model which utilizes fuzzy linguistic values to estimate human error probabilities. With the model of error probabilities are represented as analyst's estimations and natural language expression instead of numerical values. As results, the experts' estimation values about error probabilities are well agreed to the existing error probability estimation model. Thus, it was concluded that the occurrence probabilities of errors derived from the human error analysis process can be assessed by nominal values suggested in the previous studies. It is also expected that our analysis method can supplement the conventional HRA method because the nominal values are based on the consideration of various influencing factors such as PSFs.

• 대한전기학회논문지:전력기술부문A
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• 제54권6호
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• pp.306-314
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• 2005

In this paper, a new approach that is based on EEAC & only with network solutions for CS&S in the transient stability assessment is developed. The proposed CS&S algorithm in conjunction with EEAC to include the capability of performing on-line TSA without TDS is used to calculate the critical clearing time for stability index. In this algorithm, all generators are represented by classical models and all loads are represented by constant impedance load models. The accelerating & synchronizing power coefficient as an index is determined at its disturbance through solving network equation directly. As mentioned above, a new index for generator is generally used to determine the critical generators group. The generator rotor angle is fixed for non-critical generators group, but has equal angle increments for critical generators group. Finally, the critical clearing time is calculated from the power-angle relationship of equivalent OMIB system. The proposed CS&S algorithm currently being implemented is applied to the KEPCO system. The CS&S result was remarkably similar to TSAT program and SIME. Therefore, it was found to be suitable for a fast & highly efficient CS&S algorithm in TSA. The time of CS&S for the 139 contingencies using proposed CS&S algorithm takes less than 3 seconds on Pentium 4, 3GHz Desktop.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.121-129
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• 2002

Using recombinant Chinese hamster ovary (CHO) cells, strategies for developing high producers for the recombinant human Transforming Growth $Factor-{\beta}1$ ($TGF-{\beta}1$) protein are proposed and their physiological characteristics in cell cultures were investigated. $TGF-{\beta}1$ is a pleiotrophic polypeptide involved in various biological activities, including cell growth, differentiation, and deposition of extracellular matrix proteins. The CHO cells included human $TGF-{\beta}1$ cDNA in conjunction with a dihydrofolate reductase (DHFR) gene, which was cotransfected into the cells to amplify the transfected $TGF-{\beta}1$ cDNA. As a first-round screening of the transfected cells, a relatively high $TGF-{\beta}1$-producing cell line was selected, and then, it acquired a resistance to increasing concentrations of methotrexate (MTX) up to $60{\mu}M$,resulting in a significant improvement in its $TGF-{\beta}1$ biosynthetic ability. After applying a monoclonal selection strategy to the MTX-resistant cells, more productive cells were screened, including the APP-3, App-5, and App-8 cell lines. These high producers were compared with two other cell lines (AP-l cell line without amplification of transfected $TGF-{\beta}1$ cDNA and nontransfectant of $TGF-{\beta}1$ cDNA) in terms of cell growth, $TGF-{\beta}1$ productivity, sugar uptake, and byproduct formation, in the presence or absence of MTX in the culture medium. Consequently, both monoclonal selection as well as an investigation of the physiological characteristics were found to be needed for the efficient screening of higher $TGF-{\beta}1$ producers, even after the transfection and amplification of the transfected gene.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6227-6231
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• 2013

In the past, hepatitis B virus (HBV) infection was endemic in the general Korean population. The association of HBV infection with the occurrence of liver cancer has been well demonstrated in several epidemiologic studies. While the mortality rates of liver cancer in Korea have decreased steadily over the last decade, the presence of hepatitis B surface antigen (HBsAg) in mothers remains high at 3-4%, and 25.5% of these HBsAg positive mothers are positive for hepatitis B e antigen (HBeAg). HBV infection caused almost a quarter of hepatocellular carcinoma (HCC) cases and one-third of deaths from HCC. These aspects of HBV infection prompted the Korean government to create a vaccination program against HBV in the early 1980s. In 1995, the Communicable Disease Prevention Act (CDPA) was reformed, and the government increased the number of HBV vaccines in the National Immunization Program (NIP), driving the vaccination rate up to 95%. In 2000, the National Health Insurance Act (NHIA) was enacted, which provided increased resources for the prevention of perinatal HBV infection. Then in 2002, the Korean government, in conjunction with the Korean Medical Association (KMA), launched an HBV perinatal transmission prevention program. The prevalence of HBsAg in children had been high (4-5%) in the early 1980s, but had dropped to below 1% in 1995, and finally reached 0.2% in 2006 after the NIP had been implemented. After the success of the NIP, Korea finally obtained its first certification of achievement from the Western Pacific Regional Office of the World Health Organization (WPRO-WHO) for reaching its goal for HBV control. An age-period-cohort analysis showed a significant reduction in the liver cancer mortality rate in children and adolescents after the NIP had been implemented. In addition to its vaccination efforts, Korea launched the National Cancer Screening Program (NCSP) for 5 leading sites of cancer, including the liver, in 1999. As a consequence of this program, the 5-year liver cancer survival rate increased from 13.2% (1996-2000) to 23.3% (2003-2008). The development of both the primary and secondary prevention for liver cancer including HBV immunization and cancer screening has been of critical importance.

• 대한세포병리학회지
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• 제18권1호
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• pp.1-12
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• 2007

Approximately 70% of cervical cancers are caused by HPV types 16/18 and thus the implementation of vaccination programmes with vaccines against HPV types 16/18 will have a major impact on the incidence of cervical cancer worldwide. However, this reduction will not be seen until several decades after full implementation of such vaccination programmes since the vaccines must be given to young adolescents before exposure to the virus and women who are already sexually active are not likely to be protected. Both GSK and Merck insist that even vaccinated women must continue to participate in regular cervical screening by the most sensitive method available since the vaccine can only give protection against up to 70% of cervical cancers. It is unlikely that the current vaccines will be modified to include additional high risk HPV types in the foreseeable future. While HPV testing is highly sensitive, it is not recommended for women under 30 years of age nor for vaccinated women. Additionally, HPV testing has poor specificity. The Digene Hybrid Capture 2 test is licensed for use only in conjunction with a cytology test, not as a stand-alone test, and the high risk panel has recognised cross reactivity with low risk HPV types. None of the other HPV test methods currently commercially available are FDA approved and all must be internally validated before use. This makes comparison of test results between laboratories difficult. The most sensitive and specific screening test currently available for women of all ages is the Cytyc ThinPrep System consisting of the ThinPrep Pap Test (TPPT) and the ThinPrep Imaging System (Imager). The TPPT was the first LBC system approved by the US FDA in 1996 and there are about 4,000 processors in use worldwide. The Imager was FDA approved in 2003 and over 350 systems are in routine use, mainly in the US. 40% of TPPT in the US are processed on Imager. There is clear evidence in peer reviewed literature that the Imager increases laboratory productivity by 100% and growing evidence that Imager detects more high grade SIL than the conventional smear or manual evaluation of TPPT. This aspect is particularly important since the number of cytological abnormalities will decrease as vaccination programmes are implemented. Cytotechnologists will see fewer and fewer abnormal smears and their skills will be put at risk. By doubling throughput, Imager will allow cytotechnologists to maintain their skills.

• Molecules and Cells
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• 제42권6호
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• pp.480-494
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• 2019

Aggregates of disease-causing proteins dysregulate cellular functions, thereby causing neuronal cell loss in diverse neurodegenerative diseases. Although many in vitro or in vivo studies of protein aggregate inhibitors have been performed, a therapeutic strategy to control aggregate toxicity has not been earnestly pursued, partly due to the limitations of available aggregate models. In this study, we established a tetracycline (Tet)-inducible nuclear aggregate (${\beta}23$) expression model to screen potential lead compounds inhibiting ${\beta}23$-induced toxicity. High-throughput screening identified several natural compounds as nuclear ${\beta}23$ inhibitors, including peucedanocoumarin III (PCIII). Interestingly, PCIII accelerates disaggregation and proteasomal clearance of both nuclear and cytosolic ${\beta}23$ aggregates and protects SH-SY5Y cells from toxicity induced by ${\beta}23$ expression. Of translational relevance, PCIII disassembled fibrils and enhanced clearance of cytosolic and nuclear protein aggregates in cellular models of huntingtin and ${\alpha}$-synuclein aggregation. Moreover, cellular toxicity was diminished with PCIII treatment for polyglutamine (PolyQ)-huntingtin expression and ${\alpha}$-synuclein expression in conjunction with 6-hydroxydopamine (6-OHDA) treatment. Importantly, PCIII not only inhibited ${\alpha}$-synuclein aggregation but also disaggregated preformed ${\alpha}$-synuclein fibrils in vitro. Taken together, our results suggest that a Tet-Off ${\beta}23$ cell model could serve as a robust platform for screening effective lead compounds inhibiting nuclear or cytosolic protein aggregates. Brain-permeable PCIII or its derivatives could be beneficial for eliminating established protein aggregates.

• 한국산학기술학회논문지
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• 제22권2호
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• pp.651-658
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• 2021

풀림 방지 코팅 볼트는 주로 자동차 안전 관련 부품을 결합하는 데 사용되므로 안전성 유지를 위해 코팅 결함을 사전에 감지해야 한다. 이를 위해 이전 연구 [CNN 및 모델 시각화 기법을 사용한 코팅 볼트 불량 판별]에서는 합성곱 신경망을 사용했다. 이때 합성곱 신경망은 데이터 수가 많을수록 이미지 패턴 및 특성 분석 정확도가 증가하지만 그에 따라 학습시간이 증가한다. 또한 확보 가능한 코팅 볼트 샘플이 한정적이다. 본 연구에서는 이전 연구에 전이학습을 추가적으로 적용해 데이터 개수가 적은 경우에도 코팅 결함에 대해 정확한 분류를 하고자 한다. 전이학습을 적용할 때 학습 데이터 수와 사전 학습 데이터 ImageNet 간의 유사성을 고려해 분류층만 학습했다. 데이터 학습에는 전역 평균 풀링, 선형 서포트 벡터 머신 및 완전 연결 계층과 같은 분류층을 적용했으며, 고려한 모델 중 완전 연결 계층 방법의 분류층이 가장 높은 95% 정확도를 가진다. 추가적으로 마지막 합성곱층과 분류층을 미세 조정하면 정확도는 97%까지 향상된다. 전이학습 및 미세 조정을 이용하면 선별 정확도를 향상시킴은 물론 이전보다 학습 소요시간을 절반으로 줄일 수 있음을 보였다.