26,723 research outputs found

    Interactions between toothbrush and toothpaste particles during simulated abrasive cleaning

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    Most people clean their teeth using toothpaste, consisting of abrasive particles in a carrier fluid, and a filament based toothbrush to remove plaque and stain. In order to optimise cleaning efficiency it is important to understand how toothbrush filaments, abrasive particles and fluid interact in a tooth cleaning contact. Work has been carried out to visualise, simulate, and model the processes in teeth cleaning. Laboratory cleaning contacts were created between a toothbrush and a transparent surface. Video and short duration flash photography were used to study the processes by which a toothbrush traps abrasive particles, loads them against the counterface, and removes material. Small abrasive particles tend to be trapped at the contact between the filament tip and the counterface, whilst larger particles are trapped by clumps of filaments or at the contact with the side of a bent filament. Measurements of brush friction force were recorded during cleaning for a range of operating conditions. The presence of abrasive particles in the cleaning mixture increased the coefficient of friction, but the absolute particle concentration showed a lesser effect. It is surmised that only a few particles carry any load and cause any abrasion; increasing the particle concentration does not directly increase the number of load bearing particles. Abrasive scratch tests were also carried out, using PMMA as a wearing substrate. The scratches produced during these tests were studied. The microscopy images were used to deduce how the filaments deflect and drag, and how particles are trapped by filaments and scratch the surface. Again, it was observed that few of the brush filaments loaded particles to produce scratches, and that when a filament changes direction of travel the trapped particle is lost. Results of these studies were used to develop both qualitative and quantitative models of the process by which material is removed in teeth cleaning. The quantitative model contains, by necessity, several empirical factors, but nonetheless predictions compare well with in vitro wear results from the literature. The results were also used to draw some broad conclusions on appropriate brushing techniques for optimum tooth cleaning

    New light on the ‘Drummer of Tedworth’: conflicting narratives of witchcraft in Restoration England

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    This paper presents a definitive text of hitherto little-known early documents concerning ‘The Drummer of Tedworth’, a poltergeist case that occurred in 1662-3 and became famous not least due to its promotion by Joseph Glanvill in his demonological work, Saducismus Triumphatus. On the basis of these and other sources, it is shown how responses to the events at Tedworth evolved from anxious piety on the part of their victim, John Mompesson, to confident apologetic by Glanvill, before they were further affected by the emergence of articulate scepticism about the case

    Label-free proteomics identifies Calreticulin and GRP75/Mortalin as peripherally accessible protein biomarkers for spinal muscular atrophy

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    BACKGROUND: Spinal muscular atrophy (SMA) is a neuromuscular disease resulting from mutations in the survival motor neuron 1 (SMN1) gene. Recent breakthroughs in preclinical research have highlighted several potential novel therapies for SMA, increasing the need for robust and sensitive clinical trial platforms for evaluating their effectiveness in human patient cohorts. Given that most clinical trials for SMA are likely to involve young children, there is a need for validated molecular biomarkers to assist with monitoring disease progression and establishing the effectiveness of therapies being tested. Proteomics technologies have recently been highlighted as a potentially powerful tool for such biomarker discovery. METHODS: We utilized label-free proteomics to identify individual proteins in pathologically-affected skeletal muscle from SMA mice that report directly on disease status. Quantitative fluorescent western blotting was then used to assess whether protein biomarkers were robustly changed in muscle, skin and blood from another mouse model of SMA, as well as in a small cohort of human SMA patient muscle biopsies. RESULTS: By comparing the protein composition of skeletal muscle in SMA mice at a pre-symptomatic time-point with the muscle proteome at a late-symptomatic time-point we identified increased expression of both Calreticulin and GRP75/Mortalin as robust indicators of disease progression in SMA mice. We report that these protein biomarkers were consistently modified in different mouse models of SMA, as well as across multiple skeletal muscles, and were also measurable in skin biopsies. Furthermore, Calreticulin and GRP75/Mortalin were measurable in muscle biopsy samples from human SMA patients. CONCLUSIONS: We conclude that label-free proteomics technology provides a powerful platform for biomarker identification in SMA, revealing Calreticulin and GRP75/Mortalin as peripherally accessible protein biomarkers capable of reporting on disease progression in samples of muscle and skin

    Feasibility study of direct flow gas core reactor system

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    Direct flow gas core nuclear reactor propulsion syste

    Type I Superconductivity in YbSb2 Single Crystals

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    We present evidence of type I superconductivity in YbSb2 single crystals, from DC and AC magnetization, heat capacity and resistivity measurements. The critical temperature and critical field are determined to be Tc≈T_c\approx 1.3 K and Hc≈H_c\approx 55 Oe. A small Ginzburg-Landau parameter \kappa = 0.05, together with typical magnetization isotherms of type I superconductors, small critical field values, a strong Differential Paramagnetic Effect (DPE) signal, and a field-induced change from second to first order phase transition, confirm the type I nature of the superconductivity in YbSb2. A possible second superconducting state is observed in the radiofrequency (RF) susceptibility measurements, with Tc(2)≈T_{c}^{(2)}\approx 0.41 K and Hc(2)≈H_{c}^{(2)}\approx 430 Oe.Comment: 6 pages, 10 figure

    Piloting a manualised weight management programme (Shape Up-LD) for overweight and obese persons with mild-moderate learning disabilities: study protocol for a pilot randomised controlled trial

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    National obesity rates have dramatically risen over the last decade. Being obese significantly reduces life expectancy, increases the risk of a range of diseases, and compromises quality of life. Costs to both the National Health Service and society are high. An increased prevalence of obesity in people with learning disabilities has been demonstrated. The consequences of obesity are particularly relevant to people with learning disabilities who are already confronted by health and social inequalities. In order to provide healthcare for all, and ensure equality of treatment for people with learning disabilities, services must be developed specifically with this population in mind. The aim of this project is to pilot the evaluation of a manualised weight management programme for overweight and obese persons with mild-moderate learning disabilities (Shape Up-LD)

    Traitement multimodal de l’agressivité et de la violence chez des personnes souffrant de psychose

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    Dans cet article, les auteurs décrivent les traitements non pharmacologiques qui ont fait preuve d’efficacité pour réduire l’agressivité et la violence chez les personnes souffrant de psychose. Ils présentent ensuite une approche de formulation/planification du traitement qui aborde les influences étiologiques complexes, et les facteurs multiples qui jouent sur le maintien du comportement agressif chez ces patients. Finalement, ils présentent en exemple un cas où l’on se sert de cette approche.In this article, the authors offer a description of nonpharmacological treatments which have demonstrated effectiveness in reducing aggression and violence in patient with psychosis ; present a case formulation/treatment planning approach which addresses the complex etiological influences and multiple factors affecting maintenance of aggressive behavior in PI ; finally, they provide a case example of this approach.En este artículo, los autores describen los tratamientos no farmacológicos que han demostrado ser eficaces en la reducción de la agresividad y la violencia en las personas que sufren de psicosis. Enseguida, presentan un enfoque de formulación/planificación del tratamiento que aborda las influencias etiológicas complejas y los múltiples factores que tienen un efecto en el mantenimiento del comportamiento agresivo en estos pacientes. Finalmente, presentan como ejemplo un caso en el que se sirven de este enfoque.Neste artigo, os autores descrevem os tratamentos não farmacológicos que provaram ser eficazes para reduzir a agressividade e a violência nas pessoas que sofrem de psicose. Eles apresentam em seguida uma abordagem de formulação/planificação do tratamento que aborda as influências etimológicas complexas, e os fatores múltiplos que influenciam sobre a manutenção do comportamento agressivo nestes pacientes. Finalmente, eles apresentam o exemplo de um caso onde esta abordagem foi utilizada

    Application of laser Doppler velocimeter to chemical vapor laser system

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    A laser Doppler velocimeter (LDV) system was used to measure iodide vapor flow fields inside two different-sized tubes. Typical velocity profiles across the laser tubes were obtained with an estimated +/-1 percent bias and +/-0.3 to 0.5 percent random uncertainty in the mean values and +/-2.5 percent random uncertainty in the turbulence-intensity values. Centerline velocities and turbulence intensities for various longitudinal locations ranged from 13 to 17.5 m/sec and 6 to 20 percent, respectively. In view of these findings, the effects of turbulence should be considered for flow field modeling. The LDV system provided calibration data for pressure and mass flow systems used routinely to monitor the research laser gas flow velocity
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