• 제목/요약/키워드: screening technique

검색결과 346건 처리시간 0.03초

Multiplex PCR을 이용한 Extended-Spectrum β-Lactamase 생성 Escherichia coli와 Klebsiella pneumoniae의 Quinolone 내성 qnr유전자 검출 (Multiplex PCR for Detection of Quinolone Resistance qnr Genes in Extended-Spectrum β-Lactamase Producing Escherichia coli and Klebsiella pneumoniae)

  • 양병선
    • 대한임상검사과학회지
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    • 제39권3호
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    • pp.161-166
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    • 2007
  • To develop a rapid and reliable single-tube-based PCR technique for detection simultaneously the quinolone resistance qnrA, qnrB and qnrS genes. After multiple alignment, primers were designed to detect known qnr variants. I was used for A total of 43 extented-spectrum ${\beta}$-lactamases (ESBLs) producing Escherichia coli and Klebsiella pneumoniae isolated from university hospital were tested for screening, as with qnr genes. In optimized conditions, all positive controls confirmed the specificity of the PCR primers. Out of 43 isolates, qnrA genes were detected 19 (44.2%), qnrB genes 5 (11.7%), qnrS genes 15 (34.9%) and 8 (18.6%) isolates were not detected. I report here a fast and reliable technique for rapid screening of qnr positive strains to be used for epidemiological surveys.

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Antibody-based Screening of Porphyromonas gingivalis Proteins Specifically Produced in Patients with Chronic Periodontitis

  • Kim, Hye-Jung;Lee, Seok-Woo
    • International Journal of Oral Biology
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    • 제43권4호
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    • pp.201-207
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    • 2018
  • Porphyromonas gingivalis is among the major etiological pathogens of chronic periodontitis. The virulence mechanisms of P. gingivalis is yet to be identified as its activity is largely unknown in actual disease process. The purpose of this study is to identify antigens of P. gingivalis expressed only in patients with chronic periodontitis using a unique immunoscreening technique. Change Mediated Antigen Technology (CMAT), an antibody-based screening technique, was used to identify virulence-associated proteins of P. gingivalis that are expressed only during infection stage in patients having chronic periodontitis. Out of 13,000 recombinant clones screened, 22 tested positive for reproducible reactivity with rabbit hyperimmune anti-sera prepared against dental plaque samples acquired from periodontitis patients. The DNA sequences of these 18 genes were determined. CMAT-identified protein antigens of P. gingivalis included proteins involved in energy metabolism and biosynthesis, heme and iron binding, drug resistance, specific enzyme activities, and unknown functions. Further analysis of these genes could result in a novel insight into the virulence mechanisms of P. gingivalis.

Motility Contrast Imaging for Drug Screening Applications

  • Jeong, Kwan
    • Journal of the Optical Society of Korea
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    • 제19권4호
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    • pp.382-389
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    • 2015
  • Motility contrast imaging is a coherence-domain imaging technique that uses cellular motility as a fully endogenous imaging contrast agent. Motility is measured inside tissue using a digital holographic coherence gate that extracts dynamic speckle from fixed depths. The dynamic speckle arises from the normal organelle motion inside cells, and from the movement of the cellular membranes driven by the cytoskeleton. It measures cellular activity and the effects of temperature and osmolarity. Motion is sensitive to cytoskeletal drugs, such as the antimitotic drugs used for cancer chemotherapy, and the effects of drug combinations also can be monitored. Motility contrast imaging is a potential tissue-based assay platform for highthroughput screening of pharmaceuticals.

Fast High-throughput Screening of the H1N1 Virus by Parallel Detection with Multi-channel Microchip Electrophoresis

  • Zhang, Peng;Park, Guenyoung;Kang, Seong Ho
    • Bulletin of the Korean Chemical Society
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    • 제35권4호
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    • pp.1082-1086
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    • 2014
  • A multi-channel microchip electrophoresis (MCME) method with parallel laser-induced fluorescence (LIF) detection was developed for rapid screening of H1N1 virus. The hemagglutinin (HA) and nucleocapsid protein (NP) gene of H1N1 virus were amplified using polymerase chain reaction (PCR). The amplified PCR products of the H1N1 virus DNA (HA, 116 bp and NP, 195 bp) were simultaneously detected within 25 s in three parallel channels using an expanded laser beam and a charge-coupled device camera. The parallel separations were demonstrated using a sieving gel matrix of 0.3% poly(ethylene oxide) ($M_r$ = 8,000,000) in $1{\times}$ TBE buffer (pH 8.4) with a programmed step electric field strength (PSEFS). The method was ~20 times faster than conventional slab gel electrophoresis, without any loss of resolving power or reproducibility. The proposed MCME/PSEFS assay technique provides a simple and accurate method for fast high-throughput screening of infectious virus DNA molecules under 400 bp.

Phytochemical Screening and Biological Studies of Boerhavia Diffusa Linn

  • Gautam, Prakriti;Panthi, Sandesh;Bhandari, Prashubha;Shin, Jihoon;Yoo, Jin Cheol
    • 통합자연과학논문집
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    • 제9권1호
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    • pp.72-79
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    • 2016
  • Hexane, ethyl acetate and methanol extracts of whole plant of Boerhavia diffusa were screened for phytochemical and biological activities. Qualitative phytochemical screening via colorimetric method and the quantitative estimation of phenolic and flavonoid content were performed. Antioxidant assay using DPPH scavenging method was studied. Antimicrobial screening of plant extracts was done by cup diffusion technique. Cytotoxic activity of B. diffusa was studied by brine shrimp bioassay and anthelminthic activity was evaluated in vitro in Pheretima posthuma. This study revealed B. diffusa as a source of various phyto-constituents such as alkaloids, glycosides, saponins, tannins, carbohydrates, cardiac glycosides, flavonoids and terpenoids. Quantitative estimation of total phenol was found to be maximum in BEE i.e. $29.73{\pm}0.88$, BME $19.8{\pm}2.02$ and in BHE $9.15{\pm}0.304mgGAE/g$. Similarly, the total flavonoid content was found to be $17.44{\pm}0.75$ in BEE, $14.43{\pm}0.23$ in BHE and 3.678 mg QE/g in BME. Ethyl acetate extract showed its antibacterial activity against all tested pathogens except Escherichia coli whereas Staphylococcus aureus and Salmonella Typhi were resistant to methanol and hexane extract. The zone of inhibition (ZOI) of ethyl acetate extract against S. Typhi and B. cereus was found to be 18 mm and 14 mm respectively. The MIC value of BEE in S. Typhi was $3.125{\mu}g/ml$ and in B. cereus was $12.5{\mu}g/ml$. The preliminary screening of anticancer property of B. diffusa i.e. BSLT in methanol was found to be $165.19{\mu}g/ml$. B. diffusa was also found to contain anthelmintic property. The study helped in further exploration of medicinal properties of B. diffusa by phytochemical screening and biological activities paving the path for study and investigation in this plant.

한국산 식물중 Polyacetylene계 화합물의 검색(I) (The Screening of Polyacetylenic Compounds in Korean Plants. I.)

  • 문창규;윤미훈
    • 약학회지
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    • 제20권1호
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    • pp.44-46
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    • 1976
  • Fourteen species of umbelliferae-plants grown in Korea were examined for the presence of polyacetylenic compounds. By using the UV and IRspectrometric technique combined with TLC, the presence of polyacetylenic compounds was identified in Phellopterus littoralis $B_{ENTHAM}$ Peucedanum japonicum $T_{HUNBERG}$ and Angelica koreana $M_{AXIMOWITZ}$.

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면역크로마토그래피를 이용한 토양 및 쌀의 Cd 간이진단법 평가 (Evaluation of a Rapid Immunochromatography Technique for Determination of Cd in Soils and Rice Grains)

  • 이상필;김록영;;김성철;김원일;양재의
    • 한국토양비료학회지
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    • 제45권6호
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    • pp.900-903
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    • 2012
  • Cadmium is known to be very toxic to human health and can be relative easily translocated from soils in plants. Therefore, a rapid method for screening Cd in soils and crops has become more and more important. For this reason, we examined a rapid immunochromatograpy (ICG) test kit which uses antigen-antibody reaction based on immunoassay and chromatography. Soils and rice grains collected from mine waste-contaminated sites were determined for their Cd contents using this kit. For comparison purposes, 0.1 M HCl and ICP-OES were employed as a conventional extraction and determination method. Cadmium contents in rice grains determined using ICG technique were $0.46{\sim}2.39mg\;kg^{-1}$ and Cd contents determined using 0.1 M HCl and ICP-OES were $0.52{\sim}1.97mg\;kg^{-1}$. The correlation between these two Cd contents were statistically significant ($r^2$=0.930). The results of Cd contents in soils also showed a statistically significant relationship between these two methods ($r^2$=0.975). On the basis of these results, ICG technique can be applied to rapidly quantify Cd in crops and soils. However, further research is necessary to apply ICG technique for the field screening.

Current overshoot operation of a REBCO magnet to mitigate SCF

  • Lee, Changhyung;Hahn, Seungyong;Bang, Jeseok;Cho, Jeonwook;Kim, Seokho
    • 한국초전도ㆍ저온공학회논문지
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    • 제20권4호
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    • pp.65-69
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    • 2018
  • Due to large in-field current carrying capacity and strong mechanical strength, a REBCO wire has been regarded as a viable high temperature superconductor (HTS) option for high field MRI and > 1 GHz (>23.5 T) NMR magnets. However, a REBCO magnet is well known to have an inherent problem of field inhomogeneity, so-called 'Screening Current induced magnetic Field (SCF)'. Recently, 'field shaking' and 'current overshoot operation' techniques have been successfully demonstrated to mitigate the SCF and enhance the field homogeneity by experiments. To investigate the effectiveness of current overshooting operation technique, a numerical simulation is conducted for a test REBCO magnet composed of a stack of double pancake coils using '2D edge-element magnetic field formulation' combined with 'domain homogenization' scheme. The simulation result demonstrates that an appropriate amount of current overshoot can negate the SCF. To verify the simulation results, current overshoot experiments are conducted for the REBCO magnet in liquid nitrogen. Experimental results also demonstrate the possible application of current overshoot technique to mitigate the SCF and enhance the field homogeneity.