2,055 research outputs found

    Breakup of finite-size liquid filaments: Transition from no-breakup to breakup including substrate effects

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    This work studies the breakup of finite-size liquid filaments, when also including substrate effects, using direct numerical simulations. The study focuses on the effects of three parameters: Ohnesorge number, the ratio of the viscous forces to inertial and surface tension forces, the liquid filament aspect ratio, and where there is a substrate, a measure of the fluid slip on the substrate, i.e. slip length. Through these parameters, it is determined whether a liquid filament breaks up during the evolution toward its final equilibrium state. Three scenarios are identified: a collapse into a single droplet, the breakup into one or multiple droplets, and recoalescence into a single droplet after the breakup (or even possibly another breakup after recoalescence). The results are compared with the ones available in the literature for free-standing liquid filaments. The findings show that the presence of the substrate promotes breakup of the filament. The effect of the degree of slip on the breakup is also discussed. The parameter domain regions are comprehensively explored when including the slip effects. An experimental case is also carried out to illustrate the collapse and breakup of a finite-size silicon oil filament supported on a substrate, showcasing a critical length of the breakup in a physical configuration. Finally, direct numerical simulations reveal striking new details into the breakup pattern for low Ohnesorge numbers, where the dynamics are fast and the experimental imaging is not available; our results therefore significantly extend the range of Ohnesorge number over which filament breakup has been considered

    Self-reported quality care for knee osteoarthritis: comparisons across Denmark, Norway, Portugal and the UK

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    Objectives: To assess and compare patient perceived quality of osteoarthritis (OA) management in primary healthcare in Denmark, Norway, Portugal and the UK. Methods: Participants consulting with clinical signs and symptoms of knee OA were identified in 30 general practices and invited to complete a cross-sectional survey including quality indicators (QI) for OA care. A QI was considered as eligible if the participant had checked 'Yes' or 'No', and as achieved if the participant had checked 'Yes' to the indicator. The median percentage (with IQR and range) of eligible QIs achieved by country was determined and compared in negative binominal regression analysis. Achievement of individual QIs by country was determined and compared using logistic regression analyses. Results: A total of 354 participants self-reported QI achievement. The median percentage of eligible QIs achieved (checked 'Yes') was 48% (IQR 28%, 64%; range 0-100%) for the total sample with relatively similar medians across three of four countries. Achievement rates on individual QIs showed a large variation ranging from 11% (referral to services for losing weight) to 67% (information about the importance of exercise) with significant differences in achievement rates between the countries. Conclusions: The results indicated a potential for improvement in OA care in all four countries, but for somewhat different aspects of OA care. By exploring these differences and comparing healthcare services, ideas may be generated on how the quality might be improved across nations. Larger studies are needed to confirm and further explore the findings.EULAR Health Professional Grant; Norwegian Fund through the FYSIOPRIM project; National Institute for Health Research (NIHR) [RP-PG-0407-10 386]; Arthritis Research UK Centre in Primary Care grant [18139]; National Institute for Health Research (NIHR) Collaborations for Leadership in Applied Health Research and Care West Midlands by a Knowledge Mobilisation Research Fellowship from the National Institute for Health Research; National Institute for Health Research (NIHR); Fundacao para a Ciencia e Tecnologia [PEst-OE/MAT/UI0006/2014]info:eu-repo/semantics/publishedVersio

    Daily sunshine hours as determinant of 25-hydroxyvitamin D concentration among diabetic cardiac patients who experienced myocardial infarction hospitalized due to acute coronary syndrome: a cross-sectional study

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    Wstęp. Niedobór witaminy D jest problemem ogólnoświatowym o różnych konsekwencjach zdrowotnych. Witamina D może obniżać ryzyko niewydolności serca, jednak dowody świadczące o skuteczności suplementacji witaminą D na utrzymanie zdrowia układu sercowo-naczyniowego są sprzeczne z powodu braku odpowiedniej liczby i jakości badań klinicznych. Przyczyny braku jednoznacznych efektów potwierdzających pozytywny wpływ suplementacji witaminy D mogą być co najmniej trzy: 1) suplementacja zbyt małą ilością witaminy D lub 2) brak włączenia do badania tylko populacji z ciężkim niedoborem witaminy D, lub 3) czas trwania suplementacji. Celem pracy była charakterystyka grupy pacjentów kardiologicznych, u których stwierdzono w poprzednich badaniach najniższe stężenia 25-hydroksywitaminy D [25(OH)D].Materiał i metody. Analizie poddano wyniki 92 chorych kardiologicznych z cukrzycą w wieku 41–89 lat, którzy przeżyli zawał serca z istotnymi zmianami w tętnicach wieńcowych, hospitalizowanych z powodu ostrego zespołu wieńcowego, mieszkających w Warszawie.Wyniki. Mediana stężenia 25(OH)D w badanej populacji wyniosła 11 ng/ml (zakres: 4–28 ng/ml). Jedynym istotnym determinantem stężenia 25(OH)D był okres badania; stężenie było wyższe latem niż zimą.Wnioski. Leczenie witaminą D u polskich pacjentów kardiologicznych w celu osiągnięcia optymalnego stężenia, tj. 30 ng/ml (75 nmol/l), wydaje się konieczne i powinno być jak najszybciej wdrożone.Introduction. Vitamin D deficiency is a worldwide problem with a variety of health consequences. Vitamin D may reduce the risk of heart failure, however, evidence of the impact of vitamin D treatment on maintenance of cardiovascular health (i.e., preventing cardiovascular diseases) is conflicting due to lack of support from clinical trials. The reason for the failure of clinical trials to confirm an effect of vitamin D supplementation could be at least threefold: 1) too little vitamin D given to the participants or 2) lack of inclusion of only severely vitamin D-deficient populations or 3) study duration. The aim of this study was to characterize a group of cardiac patients who presented the lowest concentrations of 25-hydroxyvitamin D [25(OH)D]. Material and methods. Results of 92 diabetic cardiac patients aged between 41 and 89 years who experienced myocardial infarction, with significant coronary arteries changes, hospitalized due to acute coronary syndrome living in Warsaw were analyzed. Results. Patients presented median 25(OH)D concentration value of 11 ng/mL (range: 4–28 ng/mL). The only significant determinant of 25(OH)D concentration was the date of examination, with higher concentrations in summer than in winter. Conclusions. Vitamin D treatment in Polish cardiac patients aimed at reaching the optimal level of 30 ng/mL (75 nmol/L) seems to be necessary and implemented as soon as possible

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Dimensionality of Carbon Nanomaterials Determines the Binding and Dynamics of Amyloidogenic Peptides: Multiscale Theoretical Simulations

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    Experimental studies have demonstrated that nanoparticles can affect the rate of protein self-assembly, possibly interfering with the development of protein misfolding diseases such as Alzheimer's, Parkinson's and prion disease caused by aggregation and fibril formation of amyloid-prone proteins. We employ classical molecular dynamics simulations and large-scale density functional theory calculations to investigate the effects of nanomaterials on the structure, dynamics and binding of an amyloidogenic peptide apoC-II(60-70). We show that the binding affinity of this peptide to carbonaceous nanomaterials such as C60, nanotubes and graphene decreases with increasing nanoparticle curvature. Strong binding is facilitated by the large contact area available for π-stacking between the aromatic residues of the peptide and the extended surfaces of graphene and the nanotube. The highly curved fullerene surface exhibits reduced efficiency for π-stacking but promotes increased peptide dynamics. We postulate that the increase in conformational dynamics of the amyloid peptide can be unfavorable for the formation of fibril competent structures. In contrast, extended fibril forming peptide conformations are promoted by the nanotube and graphene surfaces which can provide a template for fibril-growth

    Post-stroke infection: A systematic review and meta-analysis

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    <p>Abstract</p> <p>Background</p> <p><b>s</b>troke is the main cause of disability in high-income countries, and ranks second as a cause of death worldwide. Patients with acute stroke are at risk for infections, but reported post-stroke infection rates vary considerably. We performed a systematic review and meta-analysis to estimate the pooled post-stroke infection rate and its effect on outcome.</p> <p>Methods</p> <p>MEDLINE and EMBASE were searched for studies on post-stroke infection. Cohort studies and randomized clinical trials were included when post-stroke infection rate was reported. Rates of infection were pooled after assessment of heterogeneity. Associations between population- and study characteristics and infection rates were quantified. Finally, we reviewed the association between infection and outcome.</p> <p>Results</p> <p>87 studies were included involving 137817 patients. 8 studies were restricted to patients admitted on the intensive care unit (ICU). There was significant heterogeneity between studies (P < 0.001, I<sup>2 </sup>= 97%). The overall pooled infection rate was 30% (24-36%); rates of pneumonia and urinary tract infection were 10% (95% confidence interval [CI] 9-10%) and 10% (95%CI 9-12%). For ICU studies, these rates were substantially higher with 45% (95% CI 38-52%), 28% (95%CI 18-38%) and 20% (95%CI 0-40%). Rates of pneumonia were higher in studies that specifically evaluated infections and in consecutive studies. Studies including older patients or more females reported higher rates of urinary tract infection. Pneumonia was significantly associated with death (odds ratio 3.62 (95%CI 2.80-4.68).</p> <p>Conclusions</p> <p>Infection complicated acute stroke in 30% of patients. Rates of pneumonia and urinary tract infection after stroke were 10%. Pneumonia was associated with death. Our study stresses the need to prevent infections in patients with stroke.</p

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
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