1,055 research outputs found

    Power law velocity fluctuations due to inelastic collisions in numerically simulated vibrated bed of powder}

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    Distribution functions of relative velocities among particles in a vibrated bed of powder are studied both numerically and theoretically. In the solid phase where granular particles remain near their local stable states, the probability distribution is Gaussian. On the other hand, in the fluidized phase, where the particles can exchange their positions, the distribution clearly deviates from Gaussian. This is interpreted with two analogies; aggregation processes and soft-to-hard turbulence transition in thermal convection. The non-Gaussian distribution is well-approximated by the t-distribution which is derived theoretically by considering the effect of clustering by inelastic collisions in the former analogy.Comment: 7 pages, using REVTEX (Figures are inculded in text body) %%%Replacement due to rivision (Europhys. Lett., in press)%%

    Scanning Drop Friction Force Microscopy

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    Economic evaluations of interventions to optimize medication use in older adults with polypharmacy and multimorbidity: A systematic review

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    Purpose: To conduct a systematic review of the economic impact of interventions intended at optimizing medication use in older adults with multimorbidity and polypharmacy. Methods: We searched Ovid-Medline, Embase, CINAHL, Ageline, Cochrane, and Web of Science, for articles published between 2004 and 2020 that studied older adults with multi-morbidity and polypharmacy. The intervention studied had to be aimed at optimizing medication use and present results on costs. Results: Out of 3,871 studies identified by the search strategy, eleven studies were included. The interventions involved different provider types, with a majority described as a multidisciplinary team involving a pharmacist and a general practitioner, in the decision-making process. Interventions were generally associated with a reduction in medication expenditure. The benefits of the intervention in terms of clinical outcomes remain limited. Five studies were cost-benefit analyses, which had a net benefit that was either null or positive. Cost-utility and cost-effectiveness analyses resulted in incremental cost-effectiveness ratios that were generally within the willingness-to-pay thresholds of the countries in which the studies were conducted. However, the quality of the studies was generally low. Omission of key cost elements of economic evaluations, including intervention cost and payer perspective, limited interpretability. Conclusion: Interventions to optimize medication use may provide benefits that outweigh their implementation costs, but the evidence remains limited. There is a need to identify and address barriers to the scaling-up of such interventions, starting with the current incentive structures for pharmacists, physicians, and patients

    'Real-world' atrial fibrillation management in Europe: observations from the 2-year follow-up of the EURObservational Research Programme-Atrial Fibrillation General Registry Pilot Phase

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    Atrial fibrillation (AF) is commonly associated with a high risk of stroke, thromboembolism, and mortality. The 1-year follow-up of the EURObservational Research Programme-Atrial Fibrillation (EORP-AF) Pilot Registry demonstrated a high mortality but good outcomes with European Society of Cardiology guideline-adherent therapy. Whether these 'real-world' observations on patients managed by European cardiologists extend to 2 years remains uncertain

    High power cladding-pumped tunable Er-Yb fiber laser

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    We report a high-power erbium-ytterbium co-doped fiber laser, cladding-pumped at 940nm by two beam-shaped diode-stacks, with up to 29W of output power at 1568nm and with operating wavelength tunable from 1561 to 1627nm

    Glomerular filtration rate in patients with atrial fibrillation and 1-year outcomes

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    We assessed 1-year outcomes in patients with atrial fibrillation enrolled in the EurObservational Research Programme AF General Pilot Registry (EORP-AF), in relation to kidney function, as assessed by glomerular filtration rate (eGFR). In a cohort of 2398 patients (median age 69 years; 61% male), eGFR (ml/min/1.73\u2009m(2)) calculated using the CKD-EPI formula was 6580 in 35.1%, 50-79 in 47.2%, 30-49 in 13.9% and <30 in 3.7% of patients. In a logistic regression analysis, eGFR category was an independent predictor of stroke/TIA or death, with elevated odds ratios associated with severe to mild renal impairment, ie. eGFR\u2009<\u200930\u2009ml/min/1.73\u2009m(2) [OR 3.641, 95% CI 1.572-8.433, p\u2009<\u20090.0001], 30-49\u2009ml/min/1.73\u2009m(2) [OR 3.303, 95% CI 1.740-6.270, p\u2009=\u20090.0026] or 50-79\u2009ml/min/1.73\u2009m2 [OR 2.094, 95% CI 1.194-3.672, p\u2009=\u20090.0003]. The discriminant capability for the risk of death was tested among various eGFR calculation algorithms: the best was the Cockcroft-Gault equation adjusted for BSA, followed by Cockcroft-Gault equation, and CKD-EPI equation, while the worst was the MDRD equation. In conclusion in this prospective observational registry, renal function was a major determinant of adverse outcomes at 1 year, and even mild or moderate renal impairments were associated with an increased risk of stroke/TIA/death

    Angle of Repose and Angle of Marginal Stability: Molecular Dyanmics of Granular Particles

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    We present an implementation of realistic static friction in molecular dynamics (MD) simulations of granular particles. In our model, to break contacts between two particles, one has to apply a finite amount of force, determined by the Coulomb criterion. Using a two dimensional model, we show that piles generated by avalanches have a {\it finite} angle of repose θR\theta_R (finite slopes). Furthermore, these piles are stable under tilting by an angle smaller than a non-zero tilting angle θT\theta_T, showing that θR\theta_R is different from the angle of marginal stability θMS\theta_{MS}, which is the maximum angle of stable piles. These measured angles are compared to a theoretical approximation. We also measure θMS\theta_{MS} by continuously adding particles on the top of a stable pile.Comment: 14 pages, Plain Te
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