100 research outputs found

    Microfabrication and test of an integrated colloid thruster

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    This paper reports on the design, fabrication and test of an integrated colloid micropropulsion system for spacecraft attitude control using the ionic liquid EMI-BF4 as fuel. The principle of operation of the thruster is identical to electrospray ionization. The objective of the project was to demonstrate the feasibility and operability of arrays of microfabricated capillary emitters with individual extractor electrodes. This design approach results in an identical electric field distribution from one capillary to the other, avoids crosstalk and therefore allows for a more finely modulated thrust control. Spraying tests with different thruster configurations were conducted under vacuum conditions. Tests were performed with different thruster configurations and starting voltages around 700V were observed

    Prognostic impact of physical activity patterns after percutaneous coronary intervention. Protocol for a prospective longitudinal cohort. The PIPAP study.

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    Introduction Current guidelines recommend wearable activity trackers to detect insufficient physical activity (PA) and help increase PA to prevent or ameliorate cardiovascular disease. However, there is a paucity of data regarding how objectively measured PA trajectories, patterns, and sedentary time, are associated with mortality and recurrent events after percutaneous coronary intervention (PCI) in patients with established coronary artery disease (CAD). Additionally, it remains unclear if early PA and sedentary time after PCI are associated with such outcomes. Therefore, in the present study (ClinicalTrials.gov Identifier: NCT04663373), we aim to establish the associations of objectively measured PA with major adverse cardiac events and mortality at one-year follow-up. Methods and analysis In this single-centre observational study, patients with CAD will be prospectively recruited immediately after PCI. All the information from the clinical history, baseline characteristics, and outcomes during follow-up will be obtained from the CARDIOBASE registry. Accelerometer data will be collected for 18 days following hospital discharge and 14 days at one-year follow-up. PA trajectories will be identified by group-based trajectory modeling. Major adverse cardiac events and mortality will be prospectively monitored up to 1 year after PCI. All data will be collected using Research Electronic Data Capture

    Design and fabrication of an integrated MEMS-based colloid micropropulsion system

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    The design, microfabrication and initial performance results of a prototype electrospray thruster with integrated individual extractor electrodes are reported in this paper. The aim was to demonstrate increased thrust with an array of emitters spraying simultaneously. Micromachining technologies were employed to achieve large emitter density per surface area, simple integration and good structural repeatability. The novelty of this work lies in the combination of high aspect ratio capillary emitters (height of 70 microns, inner diameter of 20 microns) with individual extractor electrodes having diameters from 80 microns upwards and a spacing as low as 25 microns from the capillary tips. The individual integrated electrodes, as opposed to the standard approach of one common electrode, allow for greater uniformity in critical voltages between capillaries and more finely modulated thrust control. Tests with the newly developed thrusters using the ionic liquid EMI-BF4 show that starting voltages below 700V and currents around 300nA per emitter can be achieved

    Quantitative Flow Ratio to Predict Nontarget Vessel-Related Events at 5 Years in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Angiography-Guided Revascularization.

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    Background In ST-segment-elevation myocardial infarction, angiography-based complete revascularization is superior to culprit-lesion-only percutaneous coronary intervention. Quantitative flow ratio (QFR) is a novel, noninvasive, vasodilator-free method used to assess the hemodynamic significance of coronary stenoses. We aimed to investigate the incremental value of QFR over angiography in nonculprit lesions in patients with ST-segment-elevation myocardial infarction undergoing angiography-guided complete revascularization. Methods and Results This was a retrospective post hoc QFR analysis of untreated nontarget vessels (any degree of diameter stenosis [DS]) from the randomized multicenter COMFORTABLE AMI (Comparison of Biolimus Eluted From an Erodible Stent Coating With Bare Metal Stents in Acute ST-Elevation Myocardial Infarction) trial by assessors blinded for clinical outcomes. The primary end point was cardiac death, spontaneous nontarget vessel myocardial infarction, and clinically indicated nontarget vessel revascularization (ie, ≥70% DS by 2-dimensional quantitative coronary angiography or ≥50% DS and ischemia) at 5 years. Of 1161 patients with ST-segment-elevation myocardial infarction, 946 vessels in 617 patients were analyzable by QFR. At 5 years, the rate of the primary end point was significantly higher in patients with QFR ≤0.80 (n=35 patients, n=36 vessels) versus QFR >0.80 (n=582 patients, n=910 vessels) (62.9% versus 12.5%, respectively; hazard ratio [HR], 7.33 [95% CI, 4.54-11.83], P30% DS by 3-dimensional quantitative coronary angiography. Conclusions Our study suggests incremental value of QFR over angiography-guided percutaneous coronary intervention for nonculprit lesions among patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention

    Prognostic impact of physical activity patterns after percutaneous coronary intervention. Protocol for a prospective longitudinal cohort. The PIPAP study

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    IntroductionCurrent guidelines recommend wearable activity trackers to detect insufficient physical activity (PA) and help increase PA to prevent or ameliorate cardiovascular disease. However, there is a paucity of data regarding how objectively measured PA trajectories, patterns, and sedentary time, are associated with mortality and recurrent events after percutaneous coronary intervention (PCI) in patients with established coronary artery disease (CAD). Additionally, it remains unclear if early PA and sedentary time after PCI are associated with such outcomes. Therefore, in the present study (ClinicalTrials.gov Identifier: NCT04663373), we aim to establish the associations of objectively measured PA with major adverse cardiac events and mortality at one-year follow-up.Methods and analysisIn this single-centre observational study, patients with CAD will be prospectively recruited immediately after PCI. All the information from the clinical history, baseline characteristics, and outcomes during follow-up will be obtained from the CARDIOBASE registry. Accelerometer data will be collected for 18 days following hospital discharge and 14 days at one-year follow-up. PA trajectories will be identified by group-based trajectory modeling. Major adverse cardiac events and mortality will be prospectively monitored up to 1 year after PCI. All data will be collected using Research Electronic Data Capture

    Impact of atrial fibrillation on clinical outcomes among patients with coronary artery disease undergoing revascularisation with drug-eluting stents

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    Coronary artery disease (CAD) and atrial fibrillation (AF) are major determinants of morbidity and mortality. A combined treatment with antiplatelet agents and vitamin K antagonists limits the risk of stent thrombosis and stroke while increasing the rate of bleeding. The objective of this study was to investigate the impact of atrial fibrillation (AF) on long-term clinical outcomes in patients with CAD undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES)

    A Locus on Chromosome 5 Is Associated with Dilated Cardiomyopathy in Doberman Pinschers

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    Dilated cardiomyopathy (DCM) is a heterogeneous group of heart diseases with a strong genetic background. Currently, many human DCM cases exist where no causative mutation can be identified. DCM also occurs with high prevalence in several large dog breeds. In the Doberman Pinscher a specific DCM form characterized by arrhythmias and/or echocardiographic changes has been intensively studied by veterinary cardiologists. We performed a genome-wide association study in Doberman Pinschers. Using 71 cases and 70 controls collected in Germany we identified a genome-wide significant association to DCM on chromosome 5. We validated the association in an independent cohort collected in the United Kingdom. There is no known DCM candidate gene under the association signal. Therefore, DCM in Doberman Pinschers offers the chance of identifying a novel DCM gene that might also be relevant for human health

    A 4-item PRECISE-DAPT score for dual antiplatelet therapy duration decision-making

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    The originally-proposed PRECISE-DAPT score is a 5-item risk score supporting decision-making for dual antiplatelet therapy1 duration after PCI. It is unknown if a simplified version of the score based on 4 factors (age, hemoglobin, creatinine clearance, prior bleeding), and lacking white-blood cell count, retains potential to guide DAPT duration. The 4-item PRECISE-DAPT was used to categorize 10,081 patients who were randomized to short (3-6 months) or long (12-24 months) DAPT regimen according to high (HBR defined by PRECISE-DAPT ≥25 points) or non-high bleeding risk (PRECISE-DAPT<25) status. Long treatment duration was associated with higher bleeding rates in HBR (ARD +2.22% [95% CI +0.53 to +3.90]) but not in non-HBR patients (ARD +0.25% [−0.14 to +0.64]; pint = 0.026), and associated with lower ischemic risks in non-HBR (ARD −1.44% [95% CI −2.56 to −0.31]), but not in HBR patients (ARD +1.16% [−1.91 to +4.22]; pint = 0.11). Only non-HBR patients experienced lower net clinical adverse events (NACE) with longer DAPT (pint = 0.043). A 4-item simplified version of the PRECISE-DAPT score retains the potential to categorize patients who benefit from prolon
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