1,062 research outputs found

    Isolation and Characterization of toxin A-negative, toxin B-positive Clostridium difficile in Dublin, Ireland

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    Clostridium difficile is a major cause of infectious diarrhoea in hospitalised patients. Most pathogenic C. difficile strains produce two toxins, A and B; however, clinically relevant toxin A-negative, toxin Bpositive (A– B+ ) strains of C. difficile that cause diarrhoea and colitis in humans have been isolated worldwide. The aims of this study were to isolate and characterise A– B+ strains from two university hospitals in Dublin, Ireland. Samples positive for C. difficile were identified daily by review of ELISA results and were cultured on selective media. Following culture, toxin-specific immunoassays, IMR-90 cytotoxicity assays and PCR were used to analyse consecutive C. difficile isolates from 93 patients. Using a toxin A-specific ELISA, 52 samples produced detectable toxin. All isolates were positive using a toxin A ⁄ B ELISA. Similarly, all isolates were positive with the cytoxicity assay, although variant cytopathic effects were observed in 41 cases. PCR amplification of the toxin A and toxin B genes revealed that 41 of the previous A– B+ strains had a c. 1.7-kb deletion in the 3¢-end of the tcdA gene. Restriction enzyme analysis of these amplicons revealed the loss of polymorphic restriction sites. These 41 A– B+ isolates were designated toxinotype VIII by comparison with C. difficile strain 1470. PCR ribotyping revealed that all A– B+ isolates belonged to PCR-ribotype 017. A– B+ C. difficile isolates accounted for 44% of the isolates examined in this study, and appeared to be isolated more frequently in Dublin, Ireland, than reported rates for other countries

    Self-Doping of Gold Chains on Silicon: A New Structural Model for Si(111)5x2-Au

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    A new structural model for the Si(111)5x2-Au reconstruction is proposed and analyzed using first-principles calculations. The basic model consists of a "double honeycomb chain" decorated by Si adatoms. The 5x1 periodicity of the honeycomb chains is doubled by the presence of a half-occupied row of Si atoms that partially rebonds the chains. Additional adatoms supply electrons that dope the parent band structure and stabilize the period doubling; the optimal doping corresponds to one adatom per four 5x2 cells, in agreement with experiment. All the main features observed in scanning tunneling microscopy and photoemission are well reproduced.Comment: 4 pages, 4 figures, to appear in Phys. Rev. Lett. (preprint with high quality figures available at http://cst-www.nrl.navy.mil/~erwin/papers/ausi111

    Schiff Base Complexes of Copper(II)

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    The crystal structures of four Schiff base molecules are presented, one of which is a re-appraisal of a previously reported structure. Crystals of N,N\u27-1,2-phenylene-bis(salicylideneiminato)copper(II) have been grown from both chloroform and pyridine. The structure from chloroform shows two crystallographically distinct squareplanar molecules per asymmetric unit in an orthorhombic cell, a = 20.159(2), b = 14.918(1), c = 13.329(1) Å; space group Pna21. Two different stereochemistries are observed when pyridine is the solvent. One has square planar geometry and the other square pyramidal with a pyridine molecule bound in the fifth co-ordination site. The space group is P1 with a = 8.748(4), b = 14.499(4), c = 18.725(5) Å, α = 109.93(3), β = 91.99(2), γ = 101.64(3)°. Bis(N-phenyl pyridoxylideneiminato)copper(II) crystallises in a monoclinic cell, space group P21/c, a = 5.7037(6), b = 20.394(1), c = 10.6321(6) Å, β = 101.443(6)° with the trans square planar co-ordination geometry. In the re-appraised structure of aqua(5-phosphopyridoxylidene-DLphenylalanineato) copper(II) the complex is square pyramidal with two oxygen and one nitrogen donor from the ligand. The fourth site is occupied by a water molecule and the fifth, apical donor is a phosphate oxygen from an adjacent molecule. The space group is triclinic P1 with a = 8.697(2), b = 13.039(3), c = 12.418(3) Å, α = 110.49(2), β = 108.61(2), γ = 63.65(10)°

    Rehydration Properties of Whey Protein Isolate Powders Containing Nanoparticulated Proteins

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    peer-reviewedThe rehydration properties of original whey protein isolate (WPIC) powder and spray-dried WPI prepared from either unheated (WPIUH) or nanoparticulated WPI solutions were investigated. Nanoparticulation of whey proteins was achieved by subjecting reconstituted WPIC solutions (10% protein, w/w, pH 7.0) to heat treatment at 90 °C for 30 s with no added calcium (WPIH) or with 2.5 mM added calcium (WPIHCa). Powder surface nanostructure and elemental composition were investigated using atomic force microscopy and X-ray photoelectron spectroscopy, followed by dynamic visualisation of wetting and dissolution characteristics using environmental scanning electron microscopy. The surface of powder particles for both WPIUH and WPIC samples generally appeared smooth, while WPIH and WPIHCa displayed micro-wrinkles with more significant deposition of nitrogen and calcium elements. WPIH and WPIHCa exhibited lower wettability and solubility performance than WPIUH and WPIC during microscopic observation. This study demonstrated that heat-induced aggregation of whey proteins, in the presence or absence of added calcium, before drying increases aggregate size, alters the powder surface properties, consequently impairing their wetting characteristics. This study also developed a fundamental understanding of WPI powder obtained from nanoparticulated whey proteins, which could be applied for the development of functional whey-based ingredients in food formulations, such as nanospacers to modulate protein–protein interactions in dairy concentrates.Food Institutional Research Measur

    Nonpharmacologic Management of Orthostatic Hypotension in Older People : A Systematic Review. The SENATOR ONTOP Series

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    The research leading to these results was supported by the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement no. 305930 (SENATOR project). The sponsor did not play any role in the study design, methods, data collection and analysis, and preparation of the article.Peer reviewedPostprin

    Low noise amplication of an optically carried microwave signal: application to atom interferometry

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    In this paper, we report a new scheme to amplify a microwave signal carried on a laser light at λ\lambda=852nm. The amplification is done via a semiconductor tapered amplifier and this scheme is used to drive stimulated Raman transitions in an atom interferometer. Sideband generation in the amplifier, due to self-phase and amplitude modulation, is investigated and characterized. We also demonstrate that the amplifier does not induce any significant phase-noise on the beating signal. Finally, the degradation of the performances of the interferometer due to the amplification process is shown to be negligible

    Earth observation applications for coastal sustainability: potential and challenges for implementation

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    Copyright remains with the author(s) or their institution(s). The coast is home to unique ecosystems, where complex ecological processes take place through the interaction of terrestrial, aquatic, atmospheric, and human landscapes. However, there are considerable knowledge and data gaps in achieving effective and future change-proof sustainable management of coastal zones around the world due to both technical and social barriers, as well as governance challenges. Currently, the role of Earth observation (EO) in addressing many of the recognised information gaps is small and under-utilised. While EO can provide much of the spatiotemporal information required for historical analysis and current status mapping, and offers the advantage of global coverage; its uptake can be limited by technical and methodological challenges associated mostly with lack of capacity and infrastructure, product accuracy and accessibility, costs, and institutional acceptance. While new initiatives and recent technological progress in the EO and information technology arena aim to tackle some of these issues so that EO products can be more easily used by non-EO experts, uptake is still limited.This paper discusses how EO can potentially inform transformative practices of planning in the coastal water zone, by using examples to demonstrate the EO potential in providing information relevant to decisionmaking framed by international agreements, such as the United Nations Agenda 2030, the Convention on Biological Diversity, and the Sendai Framework for Risk Reduction. By presenting evidence for how EO can contribute to innovative opportunities and data synergies at scale, the paper discusses opportunities and challenges for a more solution-led approach to sustainable coastal management.European Union’s Horizon 2020 research and innovation programme under grant agreement No. 687289 (Co-ReSyF project), the United Kingdom’s Natural Environment Research Council (NERC) under Grant NE/E009328 (GloboLakes project), and the Future Earth Coasts project.European Union’s Horizon 2020 research and innovation programme under grant agreement No. 687289 (Co-ReSyF project); United Kingdom’s Natural Environment Research Council (NERC) under Grant NE/E009328 (GloboLakes project); Future Earth Coasts project

    Core data set on safety, efficacy, and durability of hemophilia gene therapy for a global registry: Communication from the SSC of the ISTH

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    BackgroundGene therapy for people with hemophilia (PWH) will soon become available outside current clinical trials. The World Federation of Hemophilia (WFH), in collaboration with International Society of Thrombosis and Hemostasis Scientific and Standardization Committee (ISTH SSC), the European Haemophilia Consortium (EHC), the US National Hemophilia Foundation (NHF), the American Thrombosis and Hemostasis Network (ATHN), industry gene therapy development partners and Regulatory liaisons have developed the Gene Therapy Registry (GTR), designed to collect long- term data on all PWH who receive hemophilia gene therapy.ObjectiveThe objectives of the GTR are to record the long- term safety and efficacy data post gene therapy infusion and to assess the changes in quality of life and burden of disease post- gene- therapy infusion.MethodsThe GTR is a prospective, observational, and longitudinal registry developed under the guidance of a multi- stakeholder GTR Steering Committee (GTR SC), composed of health care professionals, patient advocates, industry representatives, and regulatory agency liaisons. All PWH who receive gene therapy by clinical trial or commercial product will be invited to enrol in the registry through their hemophilia treatment centers (HTCs). The registry aims to recruit 100% of eligible post gene therapy PWH globally. Through an iterative process, and following the guidance of the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA), the GTR SC has developed a core set of data to be collected on all patients post gene therapy.ResultsThe core data set includes demographic information, vector infusion details, safety, efficacy, quality of life and burden of disease.ConclusionsThe GTR is a global effort to ensure that long term safety and efficacy outcomes are recorded and analysed and rare adverse events, in a small patient population, are identified. Many unknowns on the long- term safety and efficacy of gene therapy for hemophilia may also be addressed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163440/2/jth15023.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163440/1/jth15023_am.pd
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