748 research outputs found

    Extensive collection of femtoliter pad secretion droplets in beetle Leptinotarsa decemlineata allows nanoliter microrheology

    Full text link
    Pads of beetles are covered with long, deformable setae, each ending in a micrometric terminal plate coated with secretory fluid. It was recently shown that the layer of the pad secretion covering the terminal plates is responsible for the generation of strong attractive forces. However, less is known about the fluid itself because it is produced in extremely small quantity. We here present a first experimental investigation of the rheological properties of the pad secretion in the Colorado potato beetle {\it Leptinotarsa decemlineata}. Because the secretion is produced in an extremely small amount at the level of the terminal plate, we first develop a procedure based on capillary effects to collect the secretion. We then manage to incorporate micrometric beads, initially in the form of a dry powder, and record their thermal motion to determine the mechanical properties of the surrounding medium. We achieve such a quantitative measurement within the collected volume, much smaller than the 1μ1 {\rm \mu}l sample volume usually required for this technique. Surprisingly, the beetle secretion was found to behave as a purely viscous liquid, of high viscosity. This suggests that no specific complex fluid behaviour is needed during beetle locomotion. We build a scenario for the contact formation between the spatula at the setal tip and a substrate, during the insect walk. We show that the attachment dynamics of the insect pad computed from the high measured viscosity is in good agreement with observed insect pace. We finally discuss the consequences of the secretion viscosity on the insect adhesion

    D-dimer and risk of thromboembolic and bleeding events in patients with atrial fibrillation - observations from the ARISTOTLE trial

    Get PDF
    BackgroundD-dimer is related to adverse outcomes in arterial and venous thromboembolic diseases. ObjectivesTo evaluate the predictive value of D-dimer level for stroke, other cardiovascular events, and bleeds, in patients with atrial fibrillation (AF) treated with oral anticoagulation with apixaban or warfarin; and to evaluate the relationship between the D-dimer levels at baseline and the treatment effect of apixaban vs. warfarin. MethodsIn the ARISTOTLE trial, 18201 patients with AF were randomized to apixaban or warfarin. D-dimer was analyzed in 14878 patients at randomization. The cohort was separated into two groups; not receiving vitaminK antagonist (VKA) treatment and receiving VKA treatment at randomization. ResultsHigher D-dimer levels were associated with increased frequencies of stroke or systemic embolism (hazard ratio [HR][Q4 vs. Q1]1.72, 95% confidence interval [CI]1.14-2.59, P=0.003), death (HR[Q4 vs. Q1]4.04, 95%CI3.06-5.33) and major bleeding (HR[Q4 vs. Q1]2.47, 95%CI1.77-3.45,

    The Cardiology Audit and Registration Data Standards (CARDS), European data standards for clinical cardiology practice

    Get PDF
    AIMS: Systematic registration of data from clinical practice is important for clinical care, local, national and international registries, and audit. Data to be collected for these different purposes should be harmonized. Therefore, during Ireland's Presidency of the European Union (EU) (January to June 2004), the Department of Health and Children worked with the European Society of Cardiology, the Irish Cardiac Society, and the European Commission to develop data standards for clinical cardiology. The Cardiology Audit and Registration Data Standards (CARDS) Project aimed to agree standards for three modules of cardiovascular health information systems: acute coronary syndromes (ACS), percutaneous coronary interventions (PCI), and clinical electrophysiology (pacemakers, implantable cardioverter defibrillators, and ablation procedures). METHODS AND RESULTS: Data items from existing registries and surveys were reviewed to derive draft data standards (variables, coding, and definitions). Variables common to the three modules include demographics, risk factors, medication, and discharge and follow-up data. Modules about a procedure contain variables on the l

    Transcript of The Dory Derby Accident

    Get PDF
    This story is an excerpt from a longer interview that was collected as part of the Launching through the Surf: The Dory Fleet of Pacific City project. In this story, Don Grotjohn recounts an accident that occurred during a Dory Derby competition

    Health economic analysis of ticagrelor in patients with acute coronary syndromes intended for non-invasive therapy

    Get PDF
    Objective: To investigate the cost effectiveness of ticagrelor versus clopidogrel in patients with acute coronary syndromes (ACS) in the Platelet Inhibition and Patient Outcomes (PLATO) study who were scheduled for non-invasive management. Methods: A previously developed cost effectiveness model was used to estimate long-term costs and outcomes for patients scheduled for non-invasive management. Healthcare costs, event rates and health-related quality of life under treatment with either ticagrelor or clopidogrel over 12 months were estimated from the PLATO study. Long-term costs and health outcomes were estimated based on data from PLATO and published literature sources. To investigate the importance of different healthcare cost structures and life expectancy for the results, the analysis was carried out from the perspectives of the Swedish, UK, German and Brazilian public healthcare systems. Results: Ticagrelor was associated with lifetime quality-adjusted life-year (QALY) gains of 0.17 in Sweden, 0.16 in the UK, 0.17 in Germany and 0.13 in Brazil compared with generic clopidogrel, with increased healthcare costs of €467, €551, €739 and €574, respectively. The cost per QALY gained with ticagrelor was €2747, €3395, €4419 and €4471 from a Swedish, UK, German and Brazilian public healthcare system perspective, respectively. Probabilistic sensitivity analyses indicated that the cost per QALY gained with ticagrelor was below conventional threshold values of cost effectiveness with a high probability. Conclusions: Treatment of patients with ACS scheduled for 12 months’ non-invasive management with ticagrelor is associated with a cost per QALY gained below conventional threshold values of cost effectiveness compared with generic clopidogrel. Trial registration number NCT000391872

    Les controverses sociotechniques au prisme du Parlement

    Get PDF
    Le Parlement constitue un espace privilégié pour analyser le déploiement des controverses sociotechniques : non parce qu’il aurait la faculté de les résoudre, notamment via l’OPECST, mais parce qu’il offre de multiples occasions et modalités d’expression et de traitement de ces controverses en son sein. Espace hétérogène et poreux, il participe d’une nouvelle gouvernance des risques, plus soucieuse de leur stabilisation que de leur réduction définitive.The French Parliament offers an ideal place to analyze the unfolding of sociotechnical controversies. Not that it has any capacity to actually resolve these, including its office of science and technology; but rather because it offers a plurality of opportunities for controversies to play out within its two chambers. As a heterogeneous and porous institution, it takes part in a newly formed risk governance that aims to manage rather than definitely solve risk issues

    Bragg coherent x-ray diffractive imaging of a single indium phosphide nanowire

    Get PDF
    Three-dimensional (3D) Bragg coherent x-ray diffractive imaging (CXDI) with a nanofocused beam was applied to quantitatively map the internal strain field of a single indium phosphide nanowire. The quantitative values of the strain were obtained by pre-characterization of the beam profile with transmission ptychography on a test sample. Our measurements revealed the 3D strain distribution in a region of 150 nm below the catalyst Au particle. We observed a slight gradient of the strain in the range of ±0.6% along the [111] growth direction of the nanowire. We also determined the spatial resolution in our measurements to be about 10 nm in the direction perpendicular to the facets of the nanowire. The CXDI measurements were compared with the finite element method simulations and show a good agreement with our experimental results. The proposed approach can become an effective tool for in operando studies of the nanowires
    corecore