• Title/Summary/Keyword: ${\delta}$-component

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Expression of recombinant Bordetella pertussis filamentous hemagglutinin (FHA) antigen in Live Attenuated Salmonella typhimurium Vaccine Strain (약독화 Salmonella typhimurium 생백신 균주에서 Bordetella pertussis 의 filamentous hemagglutinin(F HA))

  • 강호영
    • Journal of Life Science
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    • v.11 no.4
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    • pp.385-391
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    • 2001
  • Filamentous hemagglutinin (FHA) is considered as an essential immunogenic component for incorporation into acellular vaccines against Bordetella pertussis, the causative agent of whooping cough. Classically, antipertussis vaccination has employed an intramuscular route. An alternative approach to stimulate mucosal and systemic immune responses is oral immunization with recombinant live vaccine carrier strains of Salmonella typhimurium. An attenuated live Salmonella vaccine sgrain($\Delta$cya $\Delta$crp) expressing recombinant FHA(rFHA) was developed. Stable expressionof rFHA was achieved by the use of balanced-lethal vector-host system. which employs an asd deletion in the host chromosome to impose in obligate requirement for diaminopimelic acid. The chromosomal $\Delta$asd mutation was complemented by a plasmid vector possessing the asd$^{+}$ gene. A 3 kb DNA fragment encoding immuno dominant regionof FHA was subcloned in-frame downstream to the ATG translation initiation codon in the multicopy Asd$^{+}$ pYA3341 vector to create pYA3457. Salmonella vaccine harboring pYA3457 expressed approximately 105kDa rFHA protein. The 100% maintenance of [YA3457 in vaccine strain was confirmed by stability examinations. Additionally, a recombinant plasmid pYA3458 was constructed to overpress His(8X)-tagged rFHA in Essherichia coli. His-tagged rFHA was purified from the E. coli strain harboring pYA3458 using Ni$^{2+}$-NTA affinity purification system.>$^{2+}$-NTA affinity purification system.

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Electrical Properties of Improved Elastomer Epoxy Resin (탄성형 에폭시의 전기적 특성평가)

  • Park, S.H.;Park, J.Y.;Lee, K.W.;Kang, S.H.;Lee, G.W.;Park, D.H.;Lim, K.J.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05e
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    • pp.53-56
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    • 2003
  • In this paper we investigated electrical properties for epoxy resin with improved mechanical property, elastomer epoxy. Investigated electrical properties are permittivity, tan $\delta$ and breakdown voltage strength(BDV). Permittivity and tan $\delta$ have dependancy on additive Quantity in general purpose epoxy resin. In particularly, those have very high values at low frequency and high temperature according to increasing component of elastomer. In case of BDV test, those materials have only a little difference due to increasing elastomer components. But in case of high quantities of elastomer, BDV has a difference. These results are represented that elastomer epoxy resin despite superior mechanical property needs many carefully thought as application electrical insulation.

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GST2 is Required for Nitrogen Starvation-Induced Filamentous Growth in Candida albicans

  • Lee, So-Hyoung;Chung, Soon-Chun;Shin, Jongheon;Oh, Ki-Bong
    • Journal of Microbiology and Biotechnology
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    • v.24 no.9
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    • pp.1207-1215
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    • 2014
  • Candida albicans, the major human fungal pathogen, undergoes morphological transition from the budding yeast form to filamentous growth in response to nitrogen starvation. In this study, we identified a new function of GST2, whose expression was required for filamentous growth of C. albicans under nitrogen-limiting conditions. The Gst2p showed Gst activity and required response to oxidative stress. The ${\Delta}gst2$ mutant displayed predominantly yeast phase growth in low ammonium media. Such morphological defect of ${\Delta}gst2$ mutants was not rescued by overexpression of Mep2p, Cph1p, or Efg1p, but was rescued by either overexpression of a hyperactive $RAS1^{G13V}$ allele or through exogenous addition of cyclic AMP. In addition, the ${\Delta}gst2$ mutants had lower levels of RAS1 transcripts than wild-type cells under conditions of nitrogen starvation. These results were consistent with the Ras1-cAMP pathway as a possible downstream target of Gst2p. These findings suggest that Gst2p is a significant component of nitrogen starvation-induced filamentation in C. albicans.

Toroidal Manifolds and Dehn Fillings on Links

  • Sayari, Nabil
    • Kyungpook Mathematical Journal
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    • v.47 no.3
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    • pp.335-340
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    • 2007
  • Let M be a hyperbolic 3-manifold such that ${\partial}M$ has at least two boundary tori ${\partial}_oM$ and ${\partial}_1M$. Suppose that M contains an essential orientable surface P of genus $g$ with one outer boundary component ${\partial}_oP$, lying in ${\partial}_oM$ and having slope ${\lambda}$ in ${\partial}_oM$, and $p$ inner boundary components ${\partial}_iP$, $i=1$, ${\cdots}$, $p$, each having slope ${\alpha}$ in ${\partial}_1M$. Let ${\beta}$ be a slope in ${\partial}_1M$ and suppose that $M({\beta})$ is toroidal. Let $\hat{T}$ be a minimal essential torus in $M({\beta})$, which means that $\hat{T}$ is pierced a minimal number of times by the core of the ${\beta}$-Dehn filling, among all essential tori in $M({\beta})$. Let $T=\hat{T}{\cap}M$ and denote by $t$ the number of components of ${\partial}T$. In this paper we prove: (i) if $t{\geq}3$, then ${\Delta}({\alpha},{\beta}){\leq}6+\frac{10g-5}{p}$, (ii) If $t=2$, then ${\Delta}({\alpha},{\beta}){\leq}13+\frac{24g-12}{p}$, (iii) If $t=1$, then ${\Delta}({\alpha},{\beta}){\leq}1$.

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Control of tilt angle in the Nematic Liquid Crystal as a Function of the Baking Temperature (소성 온도 변화를 이용한 네마틱 액정의 틸트 제어)

  • Lee, Kyung-Jun;Hwang, Jeoung-Yeon;Kim, Kang-Woo;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.67-70
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    • 2003
  • The control of tilt angle for nematic liquid crystal (NLC) with negative and positive dielectric anisotropy on the rubbed homeotropic polyimide (PI) using baking method by hot plate equipment was investigated. LC tilt angle decreased with increasing baking temperature and time. Especially, the low LC tilt angle of positive type NLC ($\Delta\varepsilon$ >0) on the rubbed homeotropic PI surface by increasing temperature and time was measured. The tilt angle of positive type NLC ($\Delta\varepsilon$ >0) is smaller than that of the negative type ($\Delta\varepsilon$ >0) on rubbed PI with increasing baking temperature and time. We consider that the tilt angle of NLC is decreased due to increasing the steric interaction between horizon component of permittivity $\varepsilon$ = of NLC and the stress of polymer side chain by high temperature.

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External mechanisms driving ecosystem changes in a coastal wetland, the Mississippi Delta, USA

  • Ryu, Junghyung;Liu, Kam-biu;McCloskey, Terrence A.;Yun, Sang-Leen
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.85-85
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    • 2022
  • The world's most extensive and active deltas, Louisiana's wetlands, are deteriorating rapidly due to multiple stressors such as the discharge of the Mississippi River, sea-level rise, and coastal retreat, the substantial but spatially and temporally variable impacts. However, the ecological and anthropogenic histories, the mode of environmental changes on a multi-millennial timescale have not been thoroughly documented. This study, a palynology-based multiproxy analysis, investigates hydrological, geological, geochemical, and anthropogenic impacts on southern Louisiana wetlands and a variety of external forcing agents influencing ecological succession. Sediment cores extracted from a small pond on a mangrove-dominate island near Port Fourchon, Louisiana, USA yielded a 4,000-year record. The site has been transformed from freshwater to saline water environments, to a mangrove dominant island over the late Holocene. The multivariate principal component analysis identified the relative strength of external drivers responsible for each ecological shift. The Mississippi River delta cycle (lobe switching) was the dominant driver of ecosystem changes during the late Holocene, while relative sea-level rise, tropical cyclones, climate, and anthropogenic effects have been the main drivers late in the site's history.

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A Study on the High Frequency Properties of Mn-Zn ferrite with Re2O3(R=Dy, Gd, Ho) Addition (Re2O3(R=Dy, Gd, Ho)첨가에 따른 Mn-Zn ferrite의 고주파 특성에 관한 연구)

  • 최우성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.6
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    • pp.538-548
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    • 2003
  • We studied effects by Re$_2$O$_3$(R=Dy, Gd, Ho) addition on the properties of Mn-Zn ferrite. The doping concentration range from 0.05 wt% to 0.25 wt%. All samples were prepared by standard fabrication of ceramics. With increasing the rare earth oxides, specific density and initial permeability increased on the whole. But, the tendencies such as upper result had the measured value on limitation and characteristics saturated or decreased properties after that. In case of excessive addition of additive beyond some level, initial permeability properties of ferrite have gone down in spite of anomalous grain. With increasing the content of additive, both the real and imaginary component of complex permeability and the magnetic loss (tan$\delta$) increased. Because the increased rate of real component had higher than imaginary component, magnetic loss increased none the less for increasing the real component related with magnetic permeability. But, the magnetic loss of ferrite doped with the rare earth oxides was lower than that of Mn-Zn ferrite at any rate. The small amount of present rare earth oxides in Mn-Zn ferrite composition led to enhancement of resistivity in bulk, and more so in the grain boundary. It was seem to be due to the formation of mutual reaction such as between iron ions and rare earth element ions.

Investigation of the Effect of new alignment in NLC by using Dipping Effect (침지효과를 이용한 신액정배향효과에 관한 연구)

  • Lee, Jeong-Ho;Park, Tae-Kyu;Seo, Dae-Shik
    • Proceedings of the KIEE Conference
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    • 1999.07d
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    • pp.1815-1817
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    • 1999
  • In this paper, the generation of high pretilt angle in nematic liquid crystal (NLC) by dipping effect on three kinds of the rubbed polyimide (PI) surface was investigated. The generated pretilt angle of NLC increases due to dipping effect before rubbing treatment on two kinds of the rubbed PI surface with side chain. The generated pretit angle in NLC by using dipping effect after rubbing treatment on PI surface with short side chain is high compared to the PI surface with long side chain. The generated pretit angle of the positive type NLC $(\Delta{\varepsilon}>0)$ is higher as than that of the negative type NLC $({\Delta}{\varepsilon}<0)$ by using dipping effect before rubbing treatment on homeotropic layer. The generated pretilt angle of NLC is attributed to perpendicular component of permittivity ${\varepsilon}_{\perp}$ of NLC on rubbed PI surface.

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Dye Extraction and Silk Dyeing of Rubia Cordifolia Using Solvents (용제를 사용한 Rubia cordifolia의 색소 추출 및 Silk 염색)

  • Lim, Jee Young;Jang, Jeong Dae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.37 no.4
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    • pp.506-513
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    • 2013
  • Rubia cordifolia L (Indian madder) contains red color purpurin (65-67%) and yellow color munjistin (10-12%) as well as nordamncanthal (9-10%). Purpurin is a traditional red dye. The purpose of this research is to increase the dyeability of silk and light fastness of dyed silk fabric. We dyed silk fabrics after pretreatment to remove the yellow component of madder using various solvents such as ethyl acetate, ethanol, methanol, chloroform, and acetone. The total K/S value was the highest in the case of chloroform and reflectance was the lowest at the red color region from 470nm to 530nm. Chloroform dissolved the yellow color of Rubia cordifolia; in addition, we found that the total K/S value increased and the ${\Delta}E$ value decreased by chloroform pretreatment for silk dyeing.

Structure Optimization and 3D Printing Manufacture Technology of Pull Cord Switch Components Applied to Power Plant Coal Yard (발전소 저탄장에 적용되는 풀코드스위치 부품의 구조최적화 3D 프린팅 제작기술 개발)

  • Lee, Hye-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.10
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    • pp.319-330
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    • 2016
  • Recently, 3D printing technology has been applied to make a concept model and working mockup of an industrial application. On the other hand, this technology has limited applications in industrial products due to the materials and reliability of the 3D printed product. In this study, the components of a full cord switch module are proposed as a case of a 3D printed component that can be used as a substitute for a short period. These are hub-driven and lever lockup components that have the structural characteristics of breaking down frequently in the emergency operating status. To ensure the structural strength for a substitute period, research of structure optimization was performed because 3D printing technology has a limitation in the materials used. After optimizing the structure variables of the hub-driven component, reasonable results can be drawn in that the safety factors of the left and right switching mode are 1.243 (${\Delta}153.67%$) and 3.156 (${\Delta}404.96%$). The lever lockup component has a structural weak point that can break down easily on the lockup-part because of a cantilever shape and bending moment. The rib structure was applied to decrease the deflection. In addition, optimization of the structural variables was performed, showing a safety factor of 7.52(${\Delta}26%$).