• 대한임상검사과학회지
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• 제46권4호
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• pp.140-142
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• 2014

To evaluate the recovery rates to increase toxigenic C. difficile, the selective enrichment broth culture methods were compared with commonly used cytotoxin assays and toxigenic culture. First, the enrichment culture, using the selective medium broth for 2 to 5 days, was performed and then, toxigenic C. difficile was confirmed by C. difficile toxin gene-specific PCR after being cultured on C. difficile selective agar. The sensitivity of C. difficile from the enrichment culture (100%) was higher than that of C. difficile selective agar culture (93.8%), while positive predictive values (PPV) were low; 72.7% (16/22) and 88.2% (15/17). PPV of the enrichment culture are not high. Recently, combinations of C. difficile selective agar culture, C. difficile A & B assays, glutamate dehydrogenase, and nucleic acid amplification method are widely used. The enrichment culture was disadvantageous in PPV, turn-around time, and cost. So, what we performed is not considered as a common method of diagnosis of C. difficile-associated diarrhea.

• 한국식품저장유통학회지
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• 제23권6호
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• pp.759-764
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• 2016

본 연구의 목적은 가금류에서 문제가 되고 있는 살모넬라 신속검출을 위해 광학현미경 기반 이미징 시스템 적용에 앞서서 냉장온도로부터 손상된 살모넬라를 증균시키기 위한 최적의 배지를 선정하는 것이다. 대표적인 식중독 유발균주인 S. Typhimurium과 S. Enteritidis를 닭에 도말 하였고 $4^{\circ}C$에서 24시간 동안 저장한 후 BPW, LB, BHI, UPB, NB, 그리고 TSB 배지와 BG, RV, SC, SB 그리고 TBS 선택배지에 각각 6시간 동안 배양하였다. 배양 후, 2시간마다 살모넬라 균수를 측정하였고 그 결과 BHI와 BG를 선택되었다. 최종적으로 최적의 배지 선택을 위해 다양한 농도의 살모넬라를 닭에 각각 도말 후 6시간 동안 배양하면서 균수를 변화를 측정하였다. 그 결과 BHI가 냉해로부터 손상된 살모넬라를 증균시키기 위한 가장 최적의 배지로 선정되었으며 본 연구의 결과는 광학현미경 기반 이미징 시스템을 활용한 신속검출법 적용을 위한 증균배지로 이용될 것이다.

• 대한미생물학회지
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• 제11권1호
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• pp.33-48
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• 1976

The practical significance of using a selective enrichment procedure for detecion and enumeration of salmonella is well recognized. There are still various selective enrichment media has been communly used. Early years selenite broth was recomnended as an enrichment media for the isolating of salmonella. Hajna introduced a modified tetrathionate broth and demonstrated the greater efficiency to compare with the previous enrichment media. Raj also described that the new medium called dulcitol selenite enrichment and has been found to be very satisfactory, especially general implication in food poisoning. Authors tried to compare these 3 enrichment media for isolating salmonella. 1. When salmonella strains were inoculated $1{\sim}10^6$ cells per tube to these 3 enrichment media, mostly similar results were obtained between selenite broth and DS broth. In these 2 enrichment broth were showed $10^7/ml-10^8/ml$ cells of all tested salmonella strains. But in the case of TT broth it was found that the growth was $10^3/ml{\sim}10^4/ml$ cells for tested strain. 2. When E. coli, Proteus, Citrobacter were inoculate $10{\sim}10^6$ cells per tube to these 3 enrichment media. It was suggested that DS broth was showed more inhibitory action than that of selenite broth. TT broth showed high inhibition to these 3 organisms tested. 3. It was generally known that the incubation time is influenced to the frequency of salmonella detection. For this tendency, DS broth and selenite broth were showed similar results within 24 hrs to 48hrs incubation to the test. But DS broth showed more inhibitory action to E. coli and Proteus than that of selenite broth. 4. When $1{\sim}10$ cells were inoculated(per tube) to these 3 enrichment media, DS broth was found to be more sensitive than that of selenite broth.

• 한국식품과학회지
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• 제48권4호
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• pp.323-328
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• 2016

본 연구는 non-O157 EHEC의 혈청형별 증균 및 선택배지에서의 분리 조건 및 비교 시험을 하여 최적의 검출 방법을 제시하고자 하였다. EC medium with MUG broth, BRILA broth, mTSB broth with novobiocin 3종의 증균배지 성능 및 배양 조건의 비교 결과 EC-MUG 증균배지를 $42^{\circ}C$에서 24시간 배양하면 EHEC의 효율적인 증균이 이루어질 수 있을 것이라 생각된다. ENDO agar, Chromocult agar, TBX agar, CHROMagar$^{TM}$ STEC medium 4종의 선택배지에 가장 효과적인 배지를 확인결과 TBX agar가 검출율이 가장 높았으나 1종의 배지를 사용했을 경우 다양한 EHEC 혈청형 균를 검출 하기는 어렵다고 생각된다. 그러므로 EHEC를 효과적으로 검출하고자 할 경우 TBX agar와 보완이 가능한 그 외의 배지를 사용하여야 효과적인 검출이 가능할 것으로 생각된다. 또한, 각 배지가 혈청형에 따른 분리효율이 다르므로 본 연구 결과를 참조하여 가장 적합한 배지를 선택 해야 할 것으로 보인다. 향후 non-O157 EHEC의 적절한 기질을 사용하여 다양한 혈청형을 모두 검출 할 수 있는 효율적인 배지의 개발이 필요하다고 생각된다.

• Genomics & Informatics
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• 제15권2호
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• pp.56-64
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• 2017

We have previously reported that NS-398, a cyclooxygenase-2 (COX-2)-selective inhibitor, inhibited replicative cellular senescence in human dermal fibroblasts and skin aging in hairless mice. In contrast, celecoxib, another COX-2-selective inhibitor, and aspirin, a non-selective COX inhibitor, accelerated the senescence and aging. To figure out causal factors for the senescence-modulating effect of the inhibitors, we here performed cDNA microarray experiment and subsequent Gene Set Enrichment Analysis. The data showed that several senescence-related gene sets were regulated by the inhibitor treatment. NS-398 up-regulated gene sets involved in the tumor necrosis factor ${\beta}$ receptor pathway and the fructose and mannose metabolism, whereas it down-regulated a gene set involved in protein secretion. Celecoxib up-regulated gene sets involved in G2M checkpoint and E2F targets. Aspirin up-regulated the gene set involved in protein secretion, and down-regulated gene sets involved in RNA transcription. These results suggest that COX inhibitors modulate cellular senescence by different mechanisms and will provide useful information to understand senescence-modulating mechanisms of COX inhibitors.

• 한국식품영양과학회지
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• 제40권12호
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• pp.1787-1792
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• 2011

연구는 식품으로부터 Shigella spp.를 분리하기 위해서 현재 사용되고 있는 증균배지를 대상으로 증균성능을 비교하였다. GN broth, Shigella broth, SF broth, SC broth 총 4개의 증균배지를 비교하였다. S. sonnei에 대해 각 접종 수준에 대한 성장은 Shigella broth에서 $10^1$ cfu/mL 낮은 수준의 존재 시에도 성장이 확인되었다. 분리배지에서 거의 구분이 되지 않는 Morganella spp.에 대한 증균은 Shigella broth를 사용할 경우 성장이 저해되었다. 식품을 대상으로 한 S. sonnei의 증균성능은 돼지고기에서 GN broth와 SF broth가 높은 증균능력을 보였으며 소고기에서는 GN broth에서의 증균능력이 높게 나타났으나 Shigella broth에서 증균능력이 높지 않았다. 실험에 사용된 배지는 식품 종류에 따라 증균되는 특성이 상이하므로 식품에서 Shigella spp.를 분리하고자 할 경우 우선적으로 식품 특성을 고려하여 증균배지를 선택하는 것이 바람직할 것으로 생각되었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권4호
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• pp.20-26
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• 2021

In this work, an indigenous microbial consortium was obtained by selectively cultivating microbes using a long-aged petroleum-contaminated soil (Kuwait) containing recalcitrant petroleum hydrocarbons. The obtained microbial consortium was able to grow on and degrade the remaining petroleum hydrocarbons which could not have been utilized by the indigenous microbes in the original Kuwait soil. The following microbial community analysis using 16S rRNA gene sequencing suggested that the enhanced degradation of the remaining recalcitrant petroleum hydrocarbons by the novel microbial consortium may have been attributed to the selected bacterial populations belonging to Bacillus, Burkholderia, Sphingobacterium, Lachnospiraceae, Prevotella, Haemophilus, Pseudomonas, and Neisseria.

• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.772-779
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• 2005

Ammonia-oxidizing bacteria (AOB) were enriched by repeating fed-batch cultivations in an AOB-selective medium of activated sludges from a domestic wastewater treatment plant. Enriched culture showed strong capabilities of ammonia oxidation [0.810 mg $NH_4^+$-N/mg mixed liquor suspended solids (MLSS)$\cdot$day] as well as $NO_x^-$-N production (0.617 mg $NO_x^-$-N/ mg MLSS$\cdot$day). Degree of enrichment was examined through fluorescent in situ hybridization (FISH) analyses using an AOB-specific Cy3-labeled oligonucleotide probe (NSOl90) and terminal-restriction fragment length polymorphism (T-RFLP) analyses. FISH analyses confirmed that the fraction of AOB among 4',6-diamidino-2-phenylindole (DAPI)-stained cells increased from about less than $0.001\%$ to approximately $42\%$ after enrichment of AOB, and T-RFLP analyses showed that bacterial community became simpler as enrichment was continued. When the enriched culture of AOB was added (150 mg/l as dry suspended solid) to the normal activated sludge (3,000 mg/l as dry suspended solid), nitrification efficiencies were improved from 0.020 mg $NO_x^-$-N/mg MLSS$\cdot$day to 0.041 mg $NO_x^-$-N/mg MLSS$\cdot$day in a synthetic wastewater and also from 0.0007 mg $NO_x^-$-N/mg MLSS$\cdot$day to 0.0918 mg $NO_x^-$-N/mg MLSS$\cdot$day in a real domestic wastewater. Therefore, it is expected that this enrichment method could be used for improving efficiency of nitrification in wastewater treatment plants.

• Journal of Dairy Science and Biotechnology
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• 제41권3호
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• pp.103-112
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• 2023

This study aimed to assess the effectiveness of 10 different pre-enrichment methods using Real-Time polymerase chain reaction (PCR) in support of the FDA method. When the initial Cronobacter spp. (Enterobacter sakazakii) inoculation was 7.2 CFU/g, the Ct values were observed in the following order: 21.37 (Enterobacteriaceae enrichment [EE] broth), 21.95 (brain heart infusion [BHI]), 22.72 (tryptic soy broth [TSB]), 23.02 (violet red bile lactose [VRBL]), 22.31 (TSB-0.1% sodium pyruvate [SP]), 23.43 (distilled water [DW]), 24.34 (phosphate buffered saline [PBS]), 24.95 (nutrient broth [NB]), 25.82 (TSB-0.6% yeast extract [YE]), and 28.27 (violet red bile glucose [VRBG]). For an inoculation of 1.82% CFU/g of Cronobacter spp. (E. sakazakii), the Ct values were recorded in this sequence: 20.34 (EE broth), 22.16 (TSB-0.6% YE), 22.37 (BHI), 22.71 (VRBL), 22.88 (TSB), 23.01 (DW), 23.19 (NB), 23.79 (TSB-0.1% SP), 24.66 (VRBG), and 24.70 (PBS). Finally, when the inoculum of Cronobacter spp. (E. sakazakii) was 0.182 CFU/g, the Ct values followed this order: 21.93 (VRBL), 23.07 (TSB-0.6% YE), 23.31 (DW), 23.47 (PBS), 23.70 (BHI), 24.14 (TSB-0.1% SP), 25.14 (TSB), 29.00 (VRBG), 31.55 (EE broth), and were undetected in the case of NB. Consequently, these results indicate that there were no significant differences among the 10 different pre-enrichment broths. Future studies should focus on exploring pre-enrichment broths that can improve the limit of detection at very low Cronobacter spp. (E. sakazakii) concentrations and enhance the selective recovery of Cronobacter spp. (E. sakazakii) under acid, antibiotic, cold, and heat damage conditions.

• 한국전산구조공학회논문집
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• 제35권5호
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• pp.267-275
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• 2022

Non-conforming mesh를 이용해 구조적인 불연속성을 해석 시 요소 내 함수 불연속성과 특이점이 존재하며, 이로 인해 계산의 효율성이 저하된다. 본 연구에서는 이 문제를 해결하기 위해 모멘트 피팅법을 응용한 선택적 확장기법(Duster and Allix, 2020)을 토대로 새로운 고효율 확장 기법을 제시하였다. 특히, 적분과정에서의 비효율성에 초점을 두고 두가지 개선 방안을 제안하고 이를 수치 예제를 통해 검증하였다. 첫째로 음함수-모멘트간 효율적 계산을 위해 인공신경망을 도입하였으며, 기존 확장 기법에 비해 해의 정확성이 유지되면서도 효율적인 계산이 가능함을 확인하였다. 더불어, 구조 해석과 형상 표상용 격자를 분리, 낮은 밀도의 구조 해석 격자에서도 정확성이 향상되었음을 보였다.