• Journal of Food Hygiene and Safety
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• v.15 no.3
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• pp.241-247
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• 2000

The incidence of verotoxin-producing Escherichia coli(VTEC) was surveyed in domestic foods including hamburger, raw meats and vegetables from 1997 to 1999. The molecular biological characteristics of the isolates were analyzed. Three VTEC strain were isolated from 1,700 samples. Serotypes of those isolates were 0157 : H7, 026 H4, and 056 : Hl2, respectively. Serotype O26 : H4 produced VT I and VT II, and 055 Hl2 isolate produced VT I, however the 60 MDa plasmid DNA and eae gene were not found from both strains. One 0157 : H7 isolate produced VT II and harbour 60 MDa plasmid DNA, however eae gene was not found in the strain. Although they produced VT, it seemed that the virulence of two strains were relatively weak because of the lack of the eae gene. In addition, the serotype O157 : H7 isolate resistant to ampicillin and streptomycin, while isolates of serotype O26 : H4 and O55 : Hl2 were multi-resistant to antibiotics including ampicillin, carbenicillin , cephalothin, trimethoprim/sulfamethoxazole and tetracycline. Supernatants of cultures of all three isolates were showed cytotoxic effect to vero and HeLa cell

• Korean Journal of Microbiology
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• v.33 no.1
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• pp.55-65
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• 1997

16S rRNA를 분석한 연구들은 자연 생태계에서 추출한 핵산을 이용하여 16rRNA 유전자의 염기서열을 분석하거나 특정 DNA probe를 이용한 hybridization 실험이 주류를 이루어 왔다. 특히 PCR 기법이 개발됨에 따라 적은 양의 시료를 대량으로 손쉽게 증폭시킬 수 있어 다양한 분야에 응용되고 있다. 세균 군집의 구조를 이해하는데 있어서 PCR 방법의 적용 대상은 주로 16S rRNA 유전자의 염기서열 해독분야이며 해양 생태계를 대상으로 많은 연구 결과가 보고되었다(11,13,21,26). 한편 자연 생태계의 개별적 미생물 분류룬들을 검출하기 위한 특정 oligonucleotide probe의 개발방법들은 미생물 군집의 유전적 다양성에 대한 정보 파악 이외에 배양이 어려운 혐기성 세균과 같은 특정 세균들의 동정에도 이용되고 있다(3,24,55). 본고에서는 세균 군집의 구조와 다양성을 연구하는데 적용 가능한 rRNA 분석방법들을 수계 생태계를 중심으로 살펴보고자 한다.

• Electronics and Telecommunications Trends
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• v.28 no.5
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• pp.57-71
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• 2013

바이오센서 산업은 국민 삶의 질을 향상시키고 미래 국가 경쟁력을 증진시킬 수 있다는 기대 속에 고부가가치 산업 육성을 제고할 수 있는 분야로 주목 받고 있는 가운데, 실시간 진단, 고감도화, 소형화를 위한 집적화, 저가격화, 다기능화 등에 대한 이슈가 지속적으로 제기되고 있다. 이러한 이슈들을 해결할 수 있는 대안 기술로써, 높은 Q 지수를 갖는 광 마이크로 공진기에 대한 관심이 높아지고 있으며, 최근의 성공적인 연구 결과들은 차세대 미세 바이오 센서 시스템 구현과 실용화의 가능성을 높여주고 있다. 특히, 단일 분자 및 나노 입자까지도 측정 가능한 고감도의 무표지 센서 기술은 특성은, 각종 감염성 질환 및 암표지자의 실시간 조기 진단과 개인별 맞춤 치료, 환경 유해물질 검출, 신약물질 발굴 등 새로운 시장창출에 대한 기대감을 증폭시키고 있다.

• Korean Journal Plant Pathology
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• v.13 no.1
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• pp.1-4
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• 1997

Viroid-like RNA molecules were detected from the low molecular weight RNAs isolated from the Korean peonies which showed typical viroid symptoms of epinasty and dwarfing. Low molecular weight RNAs including viroid RNA molecules were purified by the Qiagen anion exchange minicolumns. Viroid-like RNA molecules showed a single viroid specific band in the native polyacrylamide gel. They were separated into two bands in the denaturing gel conditions. The band of circular form of viroid-like RNAs was crossed over the horizontal band of the linear form of viroid-like RNA molecules in 0~8 M urea gradient gel under the denaturing conditions of 37$^{\circ}C$. The two circular forms of viroid-like RNA molecules were detected in the reverse polyacrylamide gel electrophoresis. The viroid-like RNA molecules purified from the peonies were supposed to be unidentified viroid RNA molecules.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.230-231
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• 2000

최근 자동차, 항공기 등 연소과정을 수반하는 산업이 발전함에 따라 연소환경에 대한 관심이 높아지고 있다. 그런데 연소환경을 접촉식 방법으로 측정하게 되면, 측정기기가 연소환경에 영향을 주기 때문에 정확한 측정을 하기는 어렵다. 그래서 레이저를 이용한 비접촉식방법이 활용되고 있으며,$^{(1)}$ 그 중에서 LIGS(laser induced grating spectrosopy)나 DFWM(degenerate four wave mixing)$^{(1)}$ 은 신호대 잡음비가 높기 때문에 미세량으로 존재하는 분자를 검출하는데 유용할 뿐만 아니라 2차원 영상수집도 가능하다. 또한 LIGS의 시분해 신호를 분석하면 연소장내의 온도와 입자의 밀도 등을 산출할 수 있다. 본 실험에서는 대기압에서 불완전 연소장의 soot에 대한 신호를 수집, 분석하여 화염 위치에 따른 온도 변화와 soot의 농도 등을 정량적으로 조사했다.$^{(2)}$ (중략)

• Clean Technology
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• v.17 no.3
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• pp.231-237
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• 2011

Two-photon microscopy (TPM) is attracting much attention in biological imaging due to the capability of imaging deep inside the living tissues for a long period of time. For maximum utilization of TPM, it is essential to develop efficient twophoton sensors. Regarding this, many research groups are developing two-photon sensors for specific applications. In this review, we summarize recent results on selected examples of two-photon sensors for intracellular free metal ions in the live cells and tissues to provide a guideline for various imaging applications.

• Journal of the Korean Magnetics Society
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• v.21 no.5
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• pp.163-166
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• 2011

We describe modified Fowler-Nordheim (FN) field emission equation for the free-standing nanomembrane cathode, which has mechanical degrees of freedom. The derived FN equation agrees well with the experimental data. The free-standing nanomambrane cathode demonstrates its unique ability to detect large biomolecure ions.

• Food Science and Preservation
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• v.15 no.6
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• pp.872-877
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• 2008

This study was carried out to provide basic information related to improvement of flavor and consumption of cheonggukjang. Red ginseng cheonggukjang (RGC) and Rubus coreanum cheonggukjang (RCC) extracts were prepared, and their physicochemical characteristics were compared with either general cheonggukjang (GC) or non-fermented boiled soybean (BS). The moisture and crude fat contents were not significantly different among samples. RGC had the highest reducing sugar content and BS had the lowest. The free sugar content of RGC was higher than that of either GC or RCC, and the major free sugars present were glucose, fructose and sucrose. Seventeen free amino acids were detected in BS and cheonggukjang, and the content of free amino acids ranged from 1,233.8 to 2,599.6 mg/100 g. The greatest content of free amino acids was found in RGC. Color L, a and b values were highest in BS and lowest in RCC. The hardness and strength of RGC and RCC were lower than for GC.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.211-219
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• 2009

Local and seasonal populations of the oriental fruit moth, Grapholita molesta, were monitored with sex pheromone trapping and RAPD (random amplified polymorphic DNA) molecular marker to analyze their movement in apple orchards. To detect their movements among farms, pheromone traps were placed at regions between apple farms ('outside-farms') as well as within-farms ('inside-farms'). Four seasonal adult peaks were evident in apple-cultivating fields from April to October in both trappings of inside- or outside-farms. After overwintering generation, populations of inside-farms were significantly reduced with frequent insecticide applications, compared to populations of outside-farms. Within apple farms, G. molesta tended to be unevenly distributed because of significant sublocal preference. Active movements of local and seasonal populations of G. molesta were supported by gene flow analysis using RAPD marker. Monitoring data using sex pheromone and seasonal reduction in initial genetic differentiation detected in the overwintering populations suggest that there must be significant movement of G. molesta among different orchards in apple-cultivating areas.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.347-354
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• 2007

Commercialization of genetically modified (GM) plants will be required the assessment of risks associated with the release of GM plants that should include a detailed risk assessment of their impacts in human health and the environment. Prior to GM plant release, applicants should provide the information on GM crops for approval. We carried out this study to provide the molecular data for risk assessment of the GM Chinese cabbage plants with insect-resistance gene, modified CryIAc, which we obtained by Agrobacterium-transformation. From the molecular analysis with GM Chinese cabbage, we confirmed the transgene copy number and stability, the expression of the transgene, and integration region sequences between the transgene and the Chinese cabbage genome. Based on the unique integration DNA sequences, we designed specific primer set to detect GM Chinese cabbage and set up the GM cabbage detection method by qualitative PCR analysis. Qualitative analysis with GM Chinese cabbage progenies analysis was revealed the same as the result of herbicide treatment. Our results provided the molecular data for risk assessment analysis of GM Chinese cabbage and demonstrated that the primer set proposed could be useful to detect GM Chinese cabbage.