265 research outputs found

    Gastrointestinal Safety of Aspirin for a High-Dose, Multiple-Day Treatment Regimen: A Meta-Analysis of Three Randomized Controlled Trials

    Get PDF
    Background and Aim: Aspirin is a commonly used over-the-counter (OTC) agent for the symptomatic treatment of acute pain, fever, or the common cold, but data regarding safety in this context are limited. In order to characterize the safety of aspirin beyond single-dose or long-term use data, we conducted a meta-analysis of multiple-dose, multiple-day studies of OTC aspirin at a label-approved dosage. Methods: We conducted a meta-analysis of individual patient data from three Bayer-sponsored studies. The meta-analysis was performed in 2015; the individual studies were conducted between 2008 and 2012 and were of a randomized, parallel-group, placebo-controlled design. Patients received a minimum dosage of aspirin of 2000 mg/day over at least 3 days. The endpoints were patient-reported adverse events (AEs) with an emphasis on the system organ class gastrointestinal system. Event incidences were estimated and an analysis of the odds ratios (ORs) and risk differences (RDs) of aspirin versus placebo were performed. Results: Of the 819 patients included, 433 were treated with aspirin and 386 were treated with placebo. The majority of patients (85.7 %) received a median dose of aspirin of 3000 mg/day for 3 days. The incidence of the overall AEs was low and rates were comparable between the aspirin (10.9 %) and placebo (12.4 %) groups [OR: 0.86 (95 % confidence interval [CI] 0.56, 1.34); RD: -1.49 (95 % CI -6.01, 3.03)]. Gastrointestinal AEs were more common in subjects treated with aspirin (7.4 %) than with placebo (5.4 %), and although this difference did not reach statistical significance, a trend towards increased risk was observed with aspirin use [OR: 1.41 (95 % CI 0.78, 2.54); RD: 2.00 (95 % CI -1.35, 5.35)]. Nausea, upper abdominal pain, dyspepsia, and diarrhea were the most frequently reported gastrointestinal AEs. There were no reports of serious gastrointestinal complications such as bleeding, perforation, or ulceration.: Conclusions: The multiple-dose regimen of aspirin used for several days according to the OTC label is well-tolerated by otherwise healthy non-elderly subjects for short-term and symptomatic treatment of pain, fever, and the common cold. There were no reports of serious gastrointestinal complications in either of the groups

    Influence of advanced cylinder coatings on vehicular fuel economy and emissions in piston compression ring conjunction

    Get PDF
    IC engines contribute to global warming through extensive use of fossil fuel energy and emission of combustion by‐products. Innovative technologies such as cylinder de‐activation (CDA), after‐exhaust heat treatment, surface texturing and coatings are proposed to improve fuel economy and reduce emissions of the vehicle fleet. Therefore, study of coating technology through a comprehensive multi‐physics analytical model of engine top compression ring is important to ascertain ways of promoting energy savings. This paper presents a multi‐scale, multi‐physics model of the compression ring‐cylinder bore conjunction, using three alternative bore surfaces. The model comprises ring dynamics, contact tribology, heat transfer and gas blow‐by. Tribological and thermal properties of advanced coatings, such as Nickel Nanocomposite (NNC) and diamond‐like carbon (DLC) are compared with an uncoated steel bore surface as the base line configuration. Such a comprehensive analysis has not hitherto been reported in open literature, particularly with original contributions made through inclusion of salient properties of alternative bore materials for high performance race engines. Power loss and FMEP are evaluated in a dynamometric test, representative of the World‐ wide harmonised Light vehicles Test Cycle (WLTC). The NNC coating shows promising tribological improvements. The DLC coating is detrimental in terms of frictional power loss and FMEP, although it can effectively improve sealing of the combustion chamber. The differences in power loss of nominated bore surfaces are represented as fuel mass and CO emissions, using theoretical and empirical relations. For the first time the paper shows that advanced coatings can potentially mitigate the adverse environmental impacts of spark ignition (SI) engines, with significant repercussions when applied to the global gasoline‐powered vehicle fleet

    But a walking shadow: designing, performing and learning on the virtual stage

    Get PDF
    Representing elements of reality within a medium, or taking aspects from one medium and placing them in another is an act of remediation. The process of this act, however, is largely taken for granted. Despite the fact that available information enables a qualitative assessment of the history of multimedia and their influences on different fields of knowledge, there are still some areas that require more focused research attention. For example, the relationship between media evolution and new developments in scenographic practice is currently under investigation. This article explores the issue of immediacy as a condition of modern theatre in the context of digital reality. It discusses the opportunities and challenges that recent technologies present to contemporary practitioners and theatre design educators, creating a lot of scope to break with conventions. Here, we present two case studies that look into technology-mediated learning about scenography through the employment of novel computer visualization techniques. The first case study is concerned with new ways of researching and learning about theatre through creative exploration of design artefacts. The second case study investigates the role of the Immersive Virtual World Second Life™ (SL) in effective teaching of scenography, and in creating and experiencing theatrical performances

    When contact goes wrong: Negative intergroup contact promotes generalized outgroup avoidance

    Get PDF
    This paper broadens our understanding of the consequences of negative intergroup contact. Study 1 reports cross-sectional evidence that negative contact with European immigrants in Britain is not only associated with increased prejudice, but also the avoidance of future contact with this group. Studies 2A and 2B provided an experimental replication in a different intergroup context. A negative encounter with an outgroup member, but not an ingroup member, was found to reduce intentions to engage in contact with the outgroup in the future. Study 3 went on to demonstrate that the effect of negative contact on outgroup avoidance is not limited to the contacted outgroup, but is indirectly associated with reduced intentions to engage with other, secondary outgroups—an effect we refer to as avoidance generalization effect. Negative contact was also associated with lower general contact self-efficacy. Together, findings suggest that negative contact is damaging not just because it increases prejudice but also because it compromises future engagement with diversity

    Structural changes in FeOx/Îł-Al2O3 catalysts during ethylbenzene dehydrogenation

    Get PDF
    The structural changes that occur in a FeOx/γ-Al2O3 catalyst during the dehydrogenation of ethylbenzene in a fluidized CREC Riser Simulator have been investigated. Chemical and morphological changes are observed to take place as a result of reaction. Electron microscopy reveals the formation of needle-like alumina structures apparently enclosing iron oxide particles. The formation of such structures at relatively low temperatures is unexpected and has not previously been reported. Additionally, X-ray diffraction and Mössbauer spectroscopy confirmed the reduction of the oxidation state of iron, from Fe2O3 (haematite) to Fe3O4 (magnetite). Iron carbides, Fe3C and ɛ-Fe2C, were detected by electron microscopy through electron diffraction and lattice fringes analysis. Carbon deposition (coking) on the catalyst surface also occurs. The observed structural changes are likely to be closely correlated with the catalytic properties of the materials, in particular with catalyst deactivation, and thereby provide important avenues for future study of this industrially important reaction. Fe2O3/Al2O3 catalyst undergoes chemical and morphological changes during ethylbenzene dehydrogenation forming Al2O3 needles which appear to contain reduced Fe3O4 particles. Fe3C also forms during reaction

    Rigorous Formulation of Duality in Gravitational Theories

    Full text link
    In this paper we evince a rigorous formulation of duality in gravitational theories where an Einstein like equation is valid, by providing the conditions under which the Hodge duals (with respect to the metric tensor g) of T^a and R_b^a may be considered as the torsion and curvature 2-forms associated with a connection D', part of a Riemann-Cartan structure (M,g',D'), in the cases g = g' and g does not equal g', once T^a and R_b^a are the torsion and curvature 2-forms associated with a connection D part of a Riemann-Cartan structure (M,g,D). A new form for the Einstein equation involving the dual of the Riemann tensor of D is also provided, and the result is compared with others appearing in the literature.Comment: 15 page

    Oil Control Ring Friction And Low Viscosity Lubricants: A Combined Numerical and Experimental Analysis

    Get PDF
    A common strategy to reduce engine parasitic power losses is to decrease pumping and viscous friction losses through use of a low viscosity engine oil. However, reducing lubricant viscosity can also decrease the contact load carrying capacity, thus exacerbating direct interaction of contacting surfaces. This leads to boundary frictional losses in contacts prone to mixed regime lubrication. As a result, detailed experimental and modelling studies of engine component frictional behaviour is required to ensure the engine level trade-offs. This paper presents a combined experimental and numerical investigation of frictional behaviour of three-piece piston oil control rings. A bespoke tribometer replicates kinematics of the contact between a full oil control ring and the cylinder liner. The three-piece oil control ring is composed of two segments, separated by a waveform type expander. The experimental results indicate the dominance of mixed regime of lubrication throughout the stroke. This is particularly the case when the experiments are conducted at 80 °C; a typical engine sump temperature, when compared with the case of 20 °C (a typical engine start-up temperature in the UK in the Spring). A mixed hydrodynamic numerical model of the oil control ring-cylinder liner tribological interface is employed to apportion frictional contributions with their physical underlying mechanisms. The combined experimental-predictive approach provides key information for engine designers when considering the efficiency trade-offs

    Effects of Simple and Disposable Chicken Cages for Experimental Eimeria Infections

    Get PDF
    During experimental Eimeria infections in chickens, facilities are often contaminated by fecal oocysts known to be highly resistant to both chemical and enzymatic treatments. Thus, studies using experimental Eimeria infections have been limited due to the difficulty of complete elimination of residual oocysts from both cages and facilities. To overcome this limitation, simple, inexpensive, and disposable cages were constructed from cardboard boxes and tested during experimental Eimeria maxima infections. The cages were used in animal rooms with only a 1.7% evidence of coccidia contamination between adjacent cages. No significant differences in fecal oocyst output and body weight gain were noted between animals housed in disposable cages and animals housed in wire control cages. This cage design is a useful means for preventing oocyst contamination during experimental conditions, suggesting that this disposable cage design could be used for other avian infectious disease studies

    Determination of Debye Temperatures and Lamb-MĂśssbauer Factors for LnFeO3 Orthoferrite Perovskites (Ln = La, Nd, Sm, Eu, Gd)

    Get PDF
    Lanthanide orthoferrites have wide-ranging industrial uses including solar, catalytic and electronic applications. Here a series of lanthanide orthoferrite perovskites, LnFeO3 (Ln = La; Nd; Sm; Eu; Gd), prepared through a standard stoichiometric wet ball milling route using oxide precursors, has been studied. Characterisation through X-ray diffraction and X-ray fluorescence confirmed the synthesis of phase-pure or near-pure LnFeO3 compounds. 57Fe MÜssbauer spectroscopy was performed over a temperature range of 10 K to 293 K to observe hyperfine structure and to enable calculation of the recoil-free fraction and Debye temperature (θD) of each orthoferrite. Debye temperatures (Ln = La 474 K; Nd 459 K; Sm 457 K; Eu 452 K; Gd 473 K) and recoil-free fractions (Ln = La 0.827; Nd 0.817; Sm 0.816; Eu 0.812; Gd 0.826) were approximated through minimising the difference in the temperature dependent experimental Centre Shift (CS) and theoretical Isomer Shift (IS), by allowing the Debye temperature and Isomer Shift values to vary. This method of minimising the difference between theoretical and actual values yields Debye temperatures consistent with results from other studies determined through thermal analysis methods. This displays the ability of variable-temperature MÜssbauer spectroscopy to approximate Debye temperatures and recoil-free fractions, whilst observing temperature induced transitions over the temperature range observed. X-ray diffraction and Rietveld refinement show an inverse relationship between FeO6 octahedral volume and approximated Debye temperatures. Raman spectroscopy show an increase in the band positions attributed to soft modes of Ag symmetry, Ag(3) and Ag(5) from La to GdFeO3 corresponding to octahedral rotations and tilts in the [010] and [101] planes respectively

    Factor structure and construct validity of the Adult Social Care Outcomes Toolkit for Carers (ASCOT-Carer)

    Get PDF
    Background: The ASCOT-Carer is a self-report instrument designed to measure social care-related quality of life (SCRQoL). This article presents the psychometric testing and validation of the ASCOT-Carer four response-level interview (INT4) in a sample of unpaid carers of adults who receive publicly-funded social care services in England. Methods: Unpaid carers were identified through a survey of users of publicly-funded social care services in England. 387 carers completed a face-to-face or telephone interview. Data on variables hypothesised to be related to SCRQoL (for example, characteristics of the carer, cared-for person and care situation) and measures of carer experience, strain, health-related quality of life and overall QoL were collected. Relationships between these variables and overall SCRQoL score were evaluated through correlation, ANOVA and regression analysis to test the construct validity of the scale. Internal reliability was assessed using Cronbach’s alpha and feasibility by the number of missing responses. Results: The construct validity was supported by statistically significant relationships between SCRQoL and scores on instruments of related constructs, as well as with characteristics of the carer and care recipient in univariate and multivariate analyses. A Cronbach’s alpha of 0.87 (7 items) indicates that the internal reliability of the instrument is satisfactory and a low number of missing responses (<1%) indicates a high level of acceptance. Conclusions: The results provide evidence to support the construct validity, factor structure, internal reliability and feasibility of the ASCOT-Carer INT4 as an instrument for measuring social care-related quality of life of unpaid carers who care for adults with a variety of long-term conditions, disability or problems related to old age
    • …
    corecore