1,097 research outputs found

    Genetic markers in s. Paratyphi c reveal primary adaptation to pigs

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    Salmonella enterica with the identical antigenic formula 6,7:c:1,5 can be differentiated biochemically and by disease syndrome. One grouping, Salmonella Paratyphi C, is currently considered a typhoidal serovar, responsible for enteric fever in humans. The human-restricted typhoidal serovars (S. Typhi and Paratyphi A, B and C) typically display high levels of genome degradation and are cited as an example of convergent evolution for host adaptation in humans. However, S. Paratyphi C presents a different clinical picture to S. Typhi/Paratyphi A, in a patient group with predisposition, raising the possibility that its natural history is different, and that infection is invasive salmonellosis rather than enteric fever. Using whole genome sequencing and metabolic pathway analysis, we compared the genomes of 17 S. Paratyphi C strains to other members of the 6,7:c:1,5 group and to two typhoidal serovars: S. Typhi and Paratyphi A. The genome degradation observed in S. Paratyphi C was much lower than S. Typhi/Paratyphi A, but similar to the other 6,7:c:1,5 strains. Genomic and metabolic comparisons revealed little to no overlap between S. Paratyphi C and the other typhoidal serovars, arguing against convergent evolution and instead providing evidence of a primary adaptation to pigs in accordance with the 6,7:c:1.5 strains

    The malleability of uranium: manipulating the charge-density wave in epitaxial films

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    We report x-ray synchrotron experiments on epitaxial films of uranium, deposited on niobium and tungsten seed layers. Despite similar lattice parameters for these refractory metals, the uranium epitaxial arrangements are different and the strains propagated along the a-axis of the uranium layers are of opposite sign. At low temperatures these changes in epitaxy result in dramatic modifications to the behavior of the charge-density wave in uranium. The differences are explained with the current theory for the electron-phonon coupling in the uranium lattice. Our results emphasize the intriguing possibilities of producing epitaxial films of elements that have complex structures like the light actinides uranium to plutonium.Comment: 6 pages, 6 figure

    Growth and Characterization of β\beta-Mn Structured CoZn Thin Films

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    Thin films of polycrystalline β\beta-Mn structure CoZn have been grown on thermally oxidized Si substrates by co-sputtering from elemental targets followed by annealing. A range of films grown with variable Co deposition power and fixed Zn deposition power were produced, so as to vary the proportions of the two elements reaching the substrate, which were annealed post-growth. Whilst all films exhibited a (211) β\beta-Mn structure CoZn texture in X-ray diffraction, transmission electron microscopy showed that the composition with the highest integrated intensity for that Bragg peak contained large vacancies and was covered by a thick ZnO cap owing to being Co-deficient overall. CoZn films deposited at ratios tuned to give the optimal volume fraction of β\beta-Mn were continuous, with crystallites up to 200~nm in size, with a much thinner ZnO cap layer. Magnetic measurements show that such optimal CoZn films have a Curie temperature TC∼420T_\mathrm{C} \sim 420~K and saturation magnetization of 120~emu/cm3^3, properties close to those reported for bulk crystals. The β\beta-Mn structure is chiral (P41_{1}32/P43_{3}32 space group) and is known to give rise to a Dzyaloshinkii-Moriya interaction (DMI) that stabilizes room-temperature skyrmions in the bulk. Our thin films are thus a potential materials platform, compatible with planar processing technology, for magnetic skyrmions arising from a bulk DMI.Comment: v2 corrects minor typographical error

    Implications of subcutaneous or intravenous delivery of trastuzumab: further insight from patient interviews in the PrefHer study

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    BACKGROUND: The 2 Cohort randomised PrefHer trial examined the preferences of HER2+ve primary breast cancer patients for intravenous (IV) or subcutaneous (SC) delivery of trastuzumab via a Single Injectable Device (SID) or hand-held syringe (HHS). The novel approach and design of the study permitted an in-depth exploration of patients' experiences, the impact that different modes of delivery had on patients' well-being and implications for future management. METHODS: The preferences, experiences and general comments of patients in the PrefHer study were collected via specific semi-structured interview schedules. Exploratory analyses of data were conducted using standard methodology. The final question invited patients to make further comments, which were divided into 9 thematic categories - future delivery, compliments, time/convenience, practical considerations, pain/discomfort, study design, side-effects, psychological impact, and perceived efficacy. RESULTS: 267/467 (57%) patients made 396 additional comments, 7 were neutral, 305 positive and 86 negative. The three top categories generating the largest number of comments were compliments and gratitude about staff and being part of PrefHer (75/396; 19%), the potential future delivery of SC trastuzumab (73/396; 18%), and practical considerations about SC administration (60/396; 15%). CONCLUSIONS: Eliciting patient preferences about routes of administration of drugs via comprehensive interviews within a randomised cross-over trial yielded rich and important information. The few negative comments made demonstrated a need for proper staff training in SC administration Patients were grateful to have been part of the trial, and would have liked to continue with SC delivery. The possibility of home administration in the future also seemed acceptable. EUDRACT NUMBER: 2010-024099-25

    An Algerian perspective on non-typhoidal Salmonella infection

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    Non-typhoidal Salmonella (NTS) represents a leading cause of food-borne disease worldwide. It is a global public health concern: more than 94 million cases and 115,000 deaths are reported every year, with a disproportionate impact in developing countries. The prevalence of multi-drug-resistant (MDR) Salmonella strains is another major health concern which affects antimicrobial treatment, as many studies report that infections caused by MDR strains are more severe than those caused by susceptible strains. In Algeria, NTS represent one of the primary causes of salmonellosis in both humans and food animal production, especially poultry. Epidemiological surveillance systems and monitoring programs for Salmonella infections are essential requirements to provide data useful for the effective detection and control of Salmonella outbreaks. The present review will supply a perspective on NTS infection, pathogenesis and antimicrobial resistance with a focus on the epidemiology of salmonellosis in Algeria

    On the accuracy of aerosol photoacoustic spectrometer calibrations using absorption by ozone

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    This is the final version of the article. Available from EGU via the DOI in this record.In recent years, photoacoustic spectroscopy has emerged as an invaluable tool for the accurate measurement of light absorption by atmospheric aerosol. Photoacoustic instruments require calibration, which can be achieved by measuring the photoacoustic signal generated by known quantities of gaseous ozone. Recent work has questioned the validity of this approach at short visible wavelengths (404 nm), indicating systematic calibration errors of the order of a factor of 2. We revisit this result and test the validity of the ozone calibration method using a suite of multipass photoacoustic cells operating at wavelengths 405, 514 and 658 nm. Using aerosolised nigrosin with mobility-selected diameters in the range 250-425 nm, we demonstrate excellent agreement between measured and modelled ensemble absorption cross sections at all wavelengths, thus demonstrating the validity of the ozone-based calibration method for aerosol photoacoustic spectroscopy at visible wavelengths.This work was funded by the Met Office. In addition, Nicholas W. Davies was supported by a NERC/Met Office Industrial Case studentship (ref 640052003). Michael I. Cotterell was supported by a Tom West Analytical Chemistry Trust Fund Fellowship. Michael I. Cotterell and Jim M. Haywood were supported by the CLARIFY-2017 Natural Environment Research Council funded proposal (NE/L013797/1)
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