• 제목/요약/키워드: dilution method

검색결과 816건 처리시간 0.03초

대한해협에서 분리한 초미세 녹조플랑크톤의 미세구조 (The Ultrastructure of the Chlorococcalean Picoplankton Isolated from the Western Channel of the Korea Strait)

  • 정익교;강윤향
    • 한국해양학회지
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    • 제30권6호
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    • pp.529-536
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    • 1995
  • 1994년 5월 대한해협 서수로 표층에서 초미세식물플랑크톤을 분리, 배양하였다. 0.2${\sim}$2.0 ${\mu}m$ 범위에서 여과분리 및 희석법으로 단일종으로 분리하여 f/2 배양액으로 배양하였다. 개체의 외형은 구형이었고 지름은 2 ${\mu}m$ 내외였으며, 배양된 개체군은 황록색을 보여주었다. 표면은 매끈하였고 세포벽으로 싸여진 세포에서 핵, 엽록체, 미토콘드리아, 골기체, 액포 등이 확인되었다. 분리된 종은 엽록소 a와 b를 갖는 색소 구성과 세포막, 틸라코이드막구성, 피레노이드 등을 포함하는 미세구조 특성으로 볼 때 녹조류에 속하는 클로렐라의 일종으로 보인다.

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Loop-mediated isothermal amplification assay for the detection of Salmonella spp. in pig feces

  • Kim, Yong Kwan;Kim, Ha-Young;Jeon, Albert Byungyun;Lee, Myoung-Heon;Bae, You-Chan;Byun, Jae-Won
    • 대한수의학회지
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    • 제54권2호
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    • pp.113-115
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    • 2014
  • Salmonella are causative agents of gastroenteritis and systemic disease in animals. The invA gene was selected as a target sequence of loop-mediated isothermal amplification (LAMP) assay for diagnosis of Salmonella infection. The detection limits for broth dilution, spiked feces and enrichment were $10^4$, $10^5$ and $10^2$ CFUs/mL, respectively. The LAMP assay developed in the present study may be a reliable method for detection of Salmonella spp. in pig feces.

Refolding of Acid-Unfolded Globin to Hemoglobin

  • 이종우
    • 대한의생명과학회지
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    • 제11권1호
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    • pp.85-88
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    • 2005
  • Hemoglobin is oxygen carrier protein within erythrocyte in blood. Apoprotein of this, globin, is synthesized in the cytosol but it's cofactor, heme, is synthesized in the mitochondria. It has not been known very well how globin receives the heme from mitochondria and folds to hemoglobin. In this folding process, the initial structure of globin seems to be very important. A small volume of globin at acid pH was added rapidly into the bulk of an egg phosphatidylcholine $60\%$ liposome, containing hemins, at neutral pH according to the Rapid Dilution method. It was observed that an acid-induced unfolding structure of globin is initially needed to receive hemins from the lipid bilayer of liposomes. Also, this conclusion was confirmed with the absorption spectrum of the refolded globin separated by centrifugation.

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GNSS 자세결정시스템의 오차해석 (Error Analysis of GNSS Attitude Determination System)

  • 황동환;이상정;박찬식
    • 제어로봇시스템학회논문지
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    • 제12권3호
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    • pp.300-306
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    • 2006
  • In this paper an error analysis of 3-dimensional GNSS attitude determination system is given. The attitude error covariance matrix is derived and analyzed. It implies that attitude errors are affected by the baseline length and configuration, the satellites numbers and geometry, receiver measurement noises and the nominal attitude of the vehicle. By defining Euler Angle Dilution Of Precision (EADOP) which is analogous to GDOP, roll, pitch and yaw errors can be efficiently analyzed. However the expression of the attitude error is too complex to get some intuitions. Therefore with a commonly adopted assumption, new expressions for attitude error are derived. The formulas are easy to compute and represent the attitude error as a function of the nominal attitude of a vehicle, the baseline configuration and the receiver noise. Using the formula, the accuracy of the attitude can be analytically predicted without the computer simulations. Applications to some widely used configurations reveal the effectiveness of the proposed method.

플라즈마 화학증착법으로 제작한 미세결정질 실리콘 박막 특성에 관한 연구 (A study on Characteristics of Microcrystalline Silicon Films Fabricated by PECVD Method)

  • 이종하;이병욱;이호년;김창교
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 춘계학술대회 및 기술 세미나 논문집 디스플레이 광소자
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    • pp.57-58
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    • 2008
  • Microcrystalline (${\mu}c$) silicon thin films were prepared on glass by plasma-enhanced-chemical-vapor-deposition (PECVD) at various substrate temperature, and dilution ratio of $H_2$ with $SiH_4$. The structural and optical properties of. the ${\mu}c-Si$ thin films were investigated using XRD and UV-VIS spectrophotometer. The ${\mu}c-Si$ thin film with 42 nm grain size was grown at optimal condition of 2.5 Torr, spacing between electrodes of 3cm, deposition time of 3000s, RF power of 200W, substrate temperature of $350^{\circ}C$, $SiH_4$ ($20%SiH_4$+80%He) of 50sccm, and $H_2$ of 100sccm.

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In vitro Inhibitory Activities of Essential Oils from Oenanthe javanica DC against Candida and Streptococcus species

  • Shin, Seung-Won
    • Natural Product Sciences
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    • 제10권6호
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    • pp.325-329
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    • 2004
  • The composition of essential oil from O. javanica was analyzed by gas chromatography-mass spectrometry. Using the broth dilution method and disk diffusion test, anti-microbial activities of the oil fraction and its main components were evaluated against various antibiotic-susceptible and resistant strains of pathogenic microorganisms. As a result of GC-MS analysis, 57 compounds, including ${\alpha}-terpinolene$ (28.1%), dl-limonene (16.0%), ${\gamma}-terpinene$ (10.3%), ${\beta}-pinene$ (9.7%) and ${\alpha}-pinene$ (6.0%) were identified in the essential oil fraction. The essential oil fraction of O. javanica and its main components exhibited significant inhibitory activities, particularly against Candida albicans (antibiotic-susceptible strains) and Streptococcus pneumoniae (antibiotic- susceptible and resistant strains). The main components of the O. javanica oil fraction displayed different patterns of activity against the three tested Candida species as exemplified by the differential minimum inhibiting concentration (MIC) values. The disk diffusion test showed that the activities were dose dependent.

Significance of a Highly Specific and Sensitive Enzyme Linked Immunosorbent Assay on Evaluation of Environmental Toxicant-Mediated Allergic Responses

  • Kim, Hyoung-Ah;Yong Heo
    • Toxicological Research
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    • 제17권
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    • pp.197-199
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    • 2001
  • Enhancement of antigen-specific IgE is a hallmark of allergic hyperresponsiveness, therefore it is necessary to adopt or develop a highly sensitive and specific assay for determination of allergen-specific IgE levels in vivo. In this presentation, we introduce an ELISA (enzyme linked immunosorbent assay) system developed to measure the levels of chicken egg ovalbumin (OVA)-specific IgE in serum. The ELISA method uses a commercially available purified rat anti-mouse IgE as a capture Ab and biotinylated OVA as a detection reagent. Avidin-peroxidase with its substrate is used for color development resulting in optical density measurement at 405 nm. The ELISA system produces a highly sensitive dose-response relation-ship between optical density levels and the dilution titer of the OVA-IgE standard serum but no cross-reaction with unrelated IgE or IgG. It is believed that the system is an Efficient tool to delineate an adjuvant effect of environmental pollutants on development of asthmatic and atopic responses.

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Synthesis and $\beta$-lactamase inhibitory activity of 6-exomethylene penamsulfone derivatives-III (In vitro $\beta$-lactamase inhibitory activity and comparative susceptibility test of 6-exomethylene penamsulfone derivatives)

  • Park, Hee-Suk;Yoon, Sang-Bae;Chaeuk Im;Yim, Chul-Bu
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1997년도 춘계학술대회
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    • pp.72-72
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    • 1997
  • 합성한 5종의 6-Exomethylene penamsulfone 유도체의 Type I, Type II, Type III, TypeIV, TEM 효소에 대한 $\beta$-lactamase저해효과를 spectrophotometric assay방법으로 측정하였다. 또한 여기서 우수한 효소억제활성을 보여준 3종의 화합물을 가지고 In vitro antibacterial activity를 Agar dilution method법으로 27종의 $\beta$-lactamase생성균주에 대하여, Sulbactam, Ampicillin 및 Cefoperazone과 병용투여하여 MIC를 측정하였다.

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In Vitro Activity of Cyclic Dipeptides Against Gram-Positive and Gram-Negative Anaerobic Bacteria and Radioprotective Effect on Lung Cells

  • RHEE KI-HYEONG
    • Journal of Microbiology and Biotechnology
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    • 제16권1호
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    • pp.158-162
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    • 2006
  • Cyclic dipeptides isolated from Streptomyces sp. have been shown to have antimicrobial activity as well as other potentially useful biological activities. The purpose of this study was to compare the in vitro activity of two cyclic dipeptides combined against anaerobic bacteria with the activity of other antimicrobial agents. Specifically, the in vitro activity of the combination of two cyclic dipeptides was investigated against 140 clinical isolates of anaerobic bacteria by the agar dilution method and was compared with that of erythromycin, cefoxitin, imipenem, clindamycin, and metronidazole. The cyclic dipeptide combination and imipenem were the most active antimicrobial agents tested. In addition, the cyclic dipeptide combination had a radioprotective effect on five normal human lung fibroblast cells, showing survival rates higher $(>90\%)$ than either of the two cyclic dipeptides alone $(<80\%)$.

1-Deoxynojirimycin의 급성독성 및 항균효과 (Acute Toxicity and Antimicrobial Activity of 1-Deoxynojirimycin)

  • 백남수;김영만
    • 한국식품영양학회지
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    • 제11권6호
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    • pp.629-634
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    • 1998
  • 1-Deoxynojirimycin which is a potent intestinal ${\alpha}$-glucosidase inhibitor was purified from the culture broth by ion exchange chromatography, Sephadex LH20 column chromatography, TSK gel chromatography and HPLC respectively. Acute toxicity of 1-deoxynojirimycin, which was loaded through the oral as dose of 200mg/kg, was investigated in IRC mouse. None of the tested IRC mice were not dead and increase of body weight showed also the same results in comparison with control mice. The antimicrobial susceptibility of 20 pathogenic strains against 3 antidiabetic compounds (1-deoxynojirimycin, AO-128, acarbose) were obtained by agar dilution method. All of the three antidiabetic compounds has very weak antimicrobial activity (MIC>100$\mu\textrm{g}$/ml).

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