• Title, Summary, Keyword: selective media

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Trends in Rapid Detection Methods for Food-borne pathogenic Microorganisms by Using New Technologies (신기술 이용 식중독균 신속검출법 개발 동향 분석)

  • Kim, Hyun-Joo;Kim, Yong-Soo;Chung, Myung-Sub;Oh, Deog-Hwan;Chun, Hyang-Sook;Ha, Sang-Do
    • Journal of Food Hygiene and Safety
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    • v.25 no.4
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    • pp.376-387
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    • 2010
  • Recently, speedy, convenient and easy detection technologies have been developed rapidly and on the contrary, studies on development of traditional detectors applying biochemical characteristics has gradually been decreased. This review examined trend in current studies on detection of food-borne pathogenic microorganisms in the fields of selective media, immuno-assay, Polymerase Chain Reaction (PCR), microarray, terahertz spectroscopy & imagination and so on. Most traditional methods to detect the organisms from food matrix rely on selective media and such a method have disadvantages like long time requirement and distinguishing one species only from each selective medium although they are highly economical. Various new convenient methods such as Enzyme Linked Immuno-sorbent Assay (ELISA), paper-strip kit, fluoroimmunoassay etc. have been developed. The most ideal method for detecting food-borne pathogenic microorganisms in foods should be accurate, convenient, rapid and economical. Additionally, it is needed that capabilities of quantitative analysis and automation to be applied to industries.

A Case of Clostridium difficile Pseudomembranous Colitis (Clostridium difficile 감염에 의한 위막성 대장염 1례)

  • Seo, Jung-Ho;Lee, Jong-Won;Lee, Chang-Han;Chung, Ki-Sup
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.3 no.1
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    • pp.98-104
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    • 2000
  • Pseudomembranous colitis, thought to be uncommon in children, is a bacterial, toxin-mediated inflammatory process resulting in acute or chronic diarrhea and is characterized by colonic pseudomembranes. It is mediated by toxins produced by Clostridium difficile and is increasingly recognized in pediatric population. Diagnosis is based on positive culture of C. difficile in selective media and positive test of C. difficile toxin. Oral metronidazole or vancomycin are the main treatment options but avoidance of further antibiotics should also be encouraged where possible. We have experienced a case of pseudomembranous colitis in a 4-year-old female presented with septic shock and colitis. This case was diagnosed with positive test of C. difficile toxin B and confirmed by isolation of the organism on cultire in selective media. Symptoms have been ameliorated by discontinuation of antibiotics and administration of metronidazole and oral vancomycin, and ICU care.

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Network-adaptive Selective Transport Error Control (NASTE) for Video Streaming over WLAN (무선 비디오 스트리밍을 위한 네트워크 적응형 전송오류제어 선택)

  • Moon, Sung-Tae;Kim, Jong-Won
    • Proceedings of the Korean Information Science Society Conference
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    • pp.189-192
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    • 2006
  • 무선 네트워크 환경에서의 미디어 전송은 채널의 패이딩 현상 및 채널 잡음 등으로 인한 다량의 패킷손실과 전송지연의 변동으로 급격한 화질 열화를 발생시킨다. 이러한 채널 변동이 심한 무선 네트워크 환경에서 성공적으로 미디어를 전송하기 위해서 FEC (Forward Error Correction), ARQ (Automatic Repeat reQuest) 및 인터리빙을 사용하여 오류를 복구한다. 하지만 각각의 오류제어 모드는 채널 상황 및 오류 패턴에 따라 효율성이 다르기 때문에, 채널 상황에 적응적으로 변경할 수 있는 기법이 필요하다. 본 논문에서는 무선채널 변동을 송 수신측의 피드백 정보를 통해 측정하고 이에 따라 유동적으로 가장 적합한 오류제어 모드를 선택하여 패킷손실을 최소화하는 네트워크 적응형 전송오류제어 기법인 NASTE(Network-Adaptive Selective Transport Error control)를 제안한다. 제안된 기법의 성능을 검증하기 위해 IEEE 802.11g 무선랜 환경에서 NASTE 를 구현해서, MPEG-2 미디어 전송할 때 발생하는 패킷오류를 복구함으로써 전체적인 전송률 개선을 검증한다.

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Platinum-Catalyzed and Ion-Selective Polystyrene Fibrous Membrane by Electrospinning and In-Situ Metallization Techniques

  • Hong, Seung-Hee;Lee, Sun-Ae;Nam, Jae-Do;Lee, Young-Kwan;Kim, Tae-Sung;Won, Sung-Ho
    • Macromolecular research
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    • v.16 no.3
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    • pp.204-211
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    • 2008
  • A platinum-catalyzed polyelectrolyte porous membrane was prepared by solid-state compression of electrospun polystyrene (PS) fibers and in-situ metallization of counter-balanced ionic metal sources on the polymer surface. Using this ion-exchange metal-polymer composite system, fiber entangled pores were formed in the interstitial space of the fibers, which were surrounded by sulfonic acid sites ($SO_3^-$) to give a cation-selective polyelectrolyte porous bed with an ion exchange capacity ($I_{EC}$) of 3.0 meq/g and an ionic conductivity of 0.09 S/cm. The Pt loading was estimated to be 16.32 wt% from the $SO_3^-$ ions on the surface of the sulfonated PS fibers, which interact with the cationic platinum complex, $Pt(NH_3)_4^{2+}$, at a ratio of 3:1 based on steric hindrance and the arrangement of interacting ions. This is in good agreement with the Pt loading of 15.82 wt% measured by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The Pt-loaded sulfonated PS media showed an ionic conductivity of 0.32 S/cm. The in-situ metallized platinum provided a nano-sized and strongly-bound catalyst in robust porous media, which highlights its potential use in various electrochemical and catalytic systems.

Studies on the Selective Media for Bifidobacterium infantis Maeil-K9 Using Various Carbon Sources and Antibiotics (Bifidobacterium infantis Maeil-K9 균주의 당 발효 특성 및 항생제 내성을 이용한 선택배지 개발연구)

  • 정병문;김응률;정후길;전호남
    • Korean Journal of Microbiology
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    • v.40 no.1
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    • pp.37-42
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    • 2004
  • To differentiate commercial bifidobacteia for Bifidobacterium lactis Bb-12, Bif. longum Bb-536 and Bif. infantis Maeil-K9, we studied the various carbon source, the nitrogen sources and antibiotics. Amygdalin and fructose were good candidates for carbon sources, and tryptone was suitable for nitrogen sources to design a new selective media for three commercial bifidobacteria. In the case of the amygdalin-containing medium as carbon sources, Bif. lactis Bb-12 and Bif. infantis Maeil-K9 showed good growth, and in fructose-containing medium, Bif. longum Bb-536 showed good growth. In antibiotics resistance study, the addition of 1 mg/L doxycyclin was very effective for differentiation of each bifidobacteria. Doxycyclin did not affect the growth of Bif. lactis Bb-12 and Bif. infantis Maeil-K9, but Bif. longum Bb-536 was completely inhibited by doxycyclin. Finally to confirm the selection capability of newly designed selective media, temperature-shocked bifidobacteria were cultured on them. As the results, fructose or doxycyclin containing medium showed for high growth for temperature-shocked bifidobacteria, but amygdalin containing medium showed low growth of temperature-shocked bifidobacteria.

Ammonium Ion Effects and Its In Situ Removal by Using Immobilized Adsorbent in Hybridoma Cell Culture (하이브리도마 세포배양에서 암모늄 이온의 영향 및 고정화 흡착제에 의한 암모늄 이온의 동시제거)

  • 정연호;이해익
    • KSBB Journal
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    • v.11 no.3
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    • pp.329-339
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    • 1996
  • The effects of ammonium ion on cell growth kinetics, monoclonal antibody productivity, and cell metabolism of hybridoma cells were investigated. The mouse-mouse hybridoma cell line VlIIH-8 producing mouse IgG2a was used as a model system. Ammonium ion showed an inhibitory effect on cell growth and monoclonal antibody production. New immobilized adsorbents were developed for the reduction of the inhibitory effect of ammonium ion. The ammonium ion selective zeolite, Phillipsite-Gismondine was entrapped in calcium alginate bead or in dialysis membrane and applied to the hybridoma cell culture system for the in situ removal of ammonium ion from culture media. The effects of ammonium the both serum supplemented and serum free media on the cell growth were studied by applying immobilized adsorbents of calcium alginate bead type. The results demonstrated a substantial enhancement in cell growth. Applying immobilized adsorbents of dialysis membrane type to serum supplemented media also resulted in the stimulation of cell growth, cell viability and monoclonal antibody production.

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Isolation and identification of Agrobacterium spp. using carrot disc and transformation of Nicotiana gluca by selected strains (당근 절편을 이용한 Agrobacterium spp. 분리, 동정과 선발균주에 의한 연초의 형질전환)

  • Yang, Deok-Chun;Yang, D.C.;Choi, K.T.
    • Journal of the Korean Society of Tobacco Science
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    • v.13 no.1
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    • pp.43-52
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    • 1991
  • These studies were carred out to obtain the transformant from tobacco cells by Agrobacterium spp. from crown gall and soil at the natural field in Korea, and identified their virulence. Kodo's and Clark's selective media were used for isolation of Agrobacterium spp. In these media, total of 99 strains were characterized based on the morphological characteristics of colonies. Among them 34 strains were able to induce on carrot discs. And hypervirulent strains C23-1 and K29-1 were identified as Agrobacterium tumefaciens biotype 1 and biotype 2, respectively. These strains formed fast growing, larger gall as compared to those induced by other strains on the carrot discs. Transformed tobacco callus was initiated on the phytohormone free MS medium with 250$\mu\textrm{g}$/ml carbenicillin after co-cultivation of tobacco stem explants and Agrobacteria. On the phytohormone free media, shoot was rarely formed from transformed callus. However, these shoot were teratoma shoots which were not grown as normal shoot, and teratoma shoot from transformant by C23-1 was smaller than that of K29-1.

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Manipulation of Perpendicular Anisotropy in FePt Patterned Media for Ultra-high Density Magnetic Recording

  • Kim, Hyun-Su;Noh, Jin-Seo;Roh, Jong-Wook;Chun, Dong-Won;Kim, Sung-Man;Jung, Sang-Hyun;Kang, Ho-Kwan;Jeung, Won-Yong;Lee, Woo-Young
    • Proceedings of the Korean Magnestics Society Conference
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    • pp.70-71
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    • 2010
  • In this study, We fabricated FePt-based perpendicular patterned media using a selective combination of E-beam lithography and either Ar plasma etching (deposition-first process) or FePt lift-off (deposition-last process). We employed the deposition-last process to avoid chemical and structural disordering by impinging Ar ions (deposition-first process). For a patterned medium with 100 nm patterns made by this process, the out-of-plane coercivity was measured to be 5 fold larger than its in-plane value. The deposition-last process may be a promising way to achieve ultra-high density patterned media.

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Comparison of Four Different Isolation Media for Staphylococcus aureus (황색포도상구균 분리배지 비교)

  • Oh, Min-Hee;Kang, Seong-Il;Hong, Sang-Phil;Oh, Se-Wook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.5
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    • pp.606-611
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    • 2009
  • Performance test was carried out between selective media which are generally used in Staphylococcus aureus isolation from food. Sensitivity, determined according to the appearance of characteristic colonies when 30 different S. aureus strains were tested, resulted as Baird-Parker agar (RPF)> $Petrifilm^{TM}$ Staph Express plate> Baird-Parker agar> Mannitol salt agar. Also, the four different media showed the same selectivity because all tested media did not produce the false positive colonies. Recovery efficiency from the artificially inoculated foodstuff was almost the same for the tested media. Presumptive colonies were collected from the dried fishery product using Mannitol salt agar and collected strains were tested on 4 different selective agar. Almost presumptive strains did not show the false positive colonies except for S. carnosus ssp carnosus. This strain was identified as false positive colonies on Mannitol salt agar, Baird-Parker agar and $Petrifilm^{TM}$ Staph Express plate. But Baird-Parker agar (RPF) did not show the false positive colonies with the same strains. So, it was concluded that the Baird-Parker agar (RPF) has more higher selectivity than other tested media in this experiment.