1,351 research outputs found

    Clonal spread of SCCmec type IV methicillin-resistant Staphylococcus aureus between community and hospital

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    ABSTRACTThe staphylococcal chromosome cassette (SCC)mec types of 382 hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) isolates in Taiwan were analysed over a 7-year period (1999–2005). There was an abrupt increase in SCCmec type IV in HA-MRSA during 2005. The molecular epidemiology of a subset (n = 69) of HA-MRSA isolates with SCCmec types III, IV or V was characterised and compared with that of community-acquired MRSA (CA-MRSA) (n = 26, collected during 2005). Pulsed-field gel electrophoresis revealed three major pulsotypes (A, B and C) and 15 minor clones. Pulsotypes B and C, which contained isolates carrying SCCmec types IV and V, respectively, included both CA-MRSA and HA-MRSA isolates. Among 24 toxin genes analysed, five genes had significant differential distribution between CA-MRSA and SCCmec type III HA-MRSA. Furthermore, among SCCmec type IV isolates, the seb gene was detected more commonly in HA-MRSA. Analysis of representative members of the three major pulsotypes by multilocus sequence typing revealed two sequence types (STs), namely ST239 (SCCmec III) and ST59 (SCCmec IV or SCCmec V). This suggests that ST59:SCCmec IV, which is usually community-acquired, has become an important nosocomial pathogen in the hospital studied

    Twenty-four hour efficacy with preservative free tafluprost compared with latanoprost in patients with primary open angle glaucoma or ocular hypertension

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    10openopenKonstas A.G.; Quaranta L.; Katsanos A.; Riva I.; Tsai J.C.; Giannopoulos T.; Voudouragkaki I.C.; Paschalinou E.; Floriani I.; Haidich A.B.Konstas, A. G.; Quaranta, Luciano; Katsanos, A.; Riva, Ivano; Tsai, J. C.; Giannopoulos, T.; Voudouragkaki, I. C.; Paschalinou, E.; Floriani, I.; Haidich, A. B

    New Fermions at e+^+e^- Colliders: I. Production and Decay

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    We analyze the production in e+ee^+e^- collisions of new heavy fermions stemming from extensions of the Standard Model. We write down the most general expression for the production of two heavy fermions and their subsequent decays, allowing for the polarization of the e+^+e^- initial state and taking into account the final polarization of the fermions. We then discuss the various decay modes including cascade and three body decays, and the production mechanisms, both pair production and single production in association with ordinary fermions.Comment: 21 pages (no figures), Preprint UdeM-LPN-TH-93-15

    The effect of bending loads on the dynamic behaviors of a rolling guide

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    Dynamic behaviors of ball-type contact surfaces under unbalanced bending loads are studied using point-to-point analysis, three-dimensional finite element simulation based on the Hertz Contact Theory, and a modal test. Results derived from these models are very similar but the Finite Element Model provides the best results since it allows for more elements of study, such as the steel ball, carriage, rail etc. In the study, results also show that frequencies vary slightly, but there is an obvious change in shapes. Therefore, the contact stiffness in simulations must be properly selected with the conclusion that different external loadings may affect the dynamic characteristics of such structures significantly

    GATA-2 and GATA-3 regulate trophoblast-specific gene expression in vivo.

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    We previously demonstrated that the zinc finger transcription factors GATA-2 and GATA-3 are expressed in trophoblast giant cells and that they regulate transcription from the mouse placental lactogen I gene promoter in a transfected trophoblast cell line. We present evidence here that both of these factors regulate transcription of the placental lactogen I gene, as well as the related proliferin gene, in trophoblast giant cells in vivo. Placentas lacking GATA-3 accumulate placental lactogen I and proliferi

    Induced circular dichroism of stereoregular vinyl polymers

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    Stereoregular vinyl polymers, poly(2-vinyl pyridine)s (P2VPs), were synthesized to examine the tacticity effect on the induced circular dichroism (ICD) via association with chiral acids. The ICD was found to be strongly dependent on the isotacticity of the P2VPs and the acidity of chiral acid in addition to its bulkiness

    Theoretical prediction of CNT-CF/PP composite tensile properties using various numerical modeling methods

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    Development of effective models to predict tensile properties of ‘carbon nanotube coated carbon fibre reinforced polypropylene (CNT-CF/PP)’ composites is briefly discussed. The composite taken as the reference is based on the highest growth mechanism of CNTs over carbon fibres. Halpin-Tsai and Combined Voigt-Reuss model has been implemented. Young's modulus for CNT-CF/PP composites has been found 4.5368 GPa and the tensile strength has been estimated 45.367 MPa considering the optimum operating condition of chemical vapor deposition (CVD) technique. Stiffness of the composite is represented through the stress-strain plots; stiffness is proportional to the steepness of the slope. There are slight deviations of results that have been found theoretically over the experimental issues

    Structure of the icosahedral Ti-Zr-Ni quasicrystal

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    The atomic structure of the icosahedral Ti-Zr-Ni quasicrystal is determined by invoking similarities to periodic crystalline phases, diffraction data and the results from ab initio calculations. The structure is modeled by decorations of the canonical cell tiling geometry. The initial decoration model is based on the structure of the Frank-Kasper phase W-TiZrNi, the 1/1 approximant structure of the quasicrystal. The decoration model is optimized using a new method of structural analysis combining a least-squares refinement of diffraction data with results from ab initio calculations. The resulting structural model of icosahedral Ti-Zr-Ni is interpreted as a simple decoration rule and structural details are discussed.Comment: 12 pages, 8 figure

    QED Effective Action at Finite Temperature: Two-Loop Dominance

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    We calculate the two-loop effective action of QED for arbitrary constant electromagnetic fields at finite temperature T in the limit of T much smaller than the electron mass. It is shown that in this regime the two-loop contribution always exceeds the influence of the one-loop part due to the thermal excitation of the internal photon. As an application, we study light propagation and photon splitting in the presence of a magnetic background field at low temperature. We furthermore discover a thermally induced contribution to pair production in electric fields.Comment: 34 pages, 4 figures, LaTe

    Dynamic Evolution Model of Isothermal Voids and Shocks

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    We explore self-similar hydrodynamic evolution of central voids embedded in an isothermal gas of spherical symmetry under the self-gravity. More specifically, we study voids expanding at constant radial speeds in an isothermal gas and construct all types of possible void solutions without or with shocks in surrounding envelopes. We examine properties of void boundaries and outer envelopes. Voids without shocks are all bounded by overdense shells and either inflows or outflows in the outer envelope may occur. These solutions, referred to as type X\mathcal{X} void solutions, are further divided into subtypes XI\mathcal{X}_{\rm I} and XII\mathcal{X}_{\rm II} according to their characteristic behaviours across the sonic critical line (SCL). Void solutions with shocks in envelopes are referred to as type Z\mathcal{Z} voids and can have both dense and quasi-smooth edges. Asymptotically, outflows, breezes, inflows, accretions and static outer envelopes may all surround such type Z\mathcal{Z} voids. Both cases of constant and varying temperatures across isothermal shock fronts are analyzed; they are referred to as types ZI\mathcal{Z}_{\rm I} and ZII\mathcal{Z}_{\rm II} void shock solutions. We apply the `phase net matching procedure' to construct various self-similar void solutions. We also present analysis on void generation mechanisms and describe several astrophysical applications. By including self-gravity, gas pressure and shocks, our isothermal self-similar void (ISSV) model is adaptable to various astrophysical systems such as planetary nebulae, hot bubbles and superbubbles in the interstellar medium as well as supernova remnants.Comment: 24 pages, 13 figuers, accepted by ApS
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