149 research outputs found

    Light Quark Masses with an O(a)-Improved Action

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    We present the recent Fermilab calculations of the masses of the light quarks, using tadpole-improved Sheikholeslami-Wohlert (SW) quarks. Various sources of systematic errors are studied. Our final result for the average light quark mass in the quenched approximation evaluated in the MSˉ\bar{MS} scheme is mˉq(μ=2GeV;nf=0)=(mu+md)/2=3.6±0.6MeV\bar{m}_q(\mu=2 GeV;n_f=0)= (m_u+m_d)/2=3.6 \pm 0.6 MeV.Comment: 3 pgs. 3 figures. espcrc2.sty included. Talk presented at LATTICE96(phenomenology

    Time-frequency detection algorithm for gravitational wave bursts

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    An efficient algorithm is presented for the identification of short bursts of gravitational radiation in the data from broad-band interferometric detectors. The algorithm consists of three steps: pixels of the time-frequency representation of the data that have power above a fixed threshold are first identified. Clusters of such pixels that conform to a set of rules on their size and their proximity to other clusters are formed, and a final threshold is applied on the power integrated over all pixels in such clusters. Formal arguments are given to support the conjecture that this algorithm is very efficient for a wide class of signals. A precise model for the false alarm rate of this algorithm is presented, and it is shown using a number of representative numerical simulations to be accurate at the 1% level for most values of the parameters, with maximal error around 10%.Comment: 26 pages, 15 figures, to appear in PR

    Effect of multidose drug dispensing on the time in therapeutic range in patients using vitamin-K antagonists: a randomized controlled trial

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    Background A high number of vitamin K antagonist (VKA) users have a low proportion of time in therapeutic range (TTR) resulting in a high number of bleeding and thromboembolism events. Objective Can the quality of anticoagulation be improved by dispensing VKAs via multidose drug dispensing (MDD). Method A randomized controlled trial in the Netherlands. Patients who used VKAs, >= 65 years of age with a TTR <65% were eligible for inclusion. All oral drugs were dispensed via MDD. In MDD systems, all oral chronic medication intended for one dosing moment is packed in plastic disposable pouches. Controls received VKAs by manual dispensing. The difference in TTR between the 6 months after- and 6 months before the index date. A mixed-effects model with the intervention, TTR before the index date, MDD system at baseline as covariates, and pharmacy as random effect. A per-protocol analysis was performed with all patients who completed the study as intended. Results One hundred and seventy-nine patients were included. Mean age was 80.0 (SD 6.9) years. Mean TTR during the study was 79.2 +/- 18.0% in the intervention group and 72.5 +/- 20.1% in the control group. The intervention resulted in a 5.6% (95% CI: 0.1-11.1) increase in TTR compared to the control group. Per-protocol analysis resulted in an 8.3% (95% CI: 0.99-15.61) increase in TTR compared to the control group. No differences in reduction were observed between the intervention and control group. Conclusion The quality of anticoagulation can be improved with the use of MDD systems

    Mini-, micro-, and conventional electrodes an in vivo electrophysiology and ex vivo histology head-to-head comparison

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    OBJECTIVES This study sought to assess the relative effect of catheter, tissue, and catheter-tissue parameters, on the ability to determine the amount of viable myocardium in vivo.BACKGROUND Although multiple variables impact bipolar voltages (BVs), electrode size, interelectrode spacing, and directional dependency are of particular interest with the development of catheters incorporating mini and microelectrodes.METHODS Nine swine with early reperfusion myocardial infarctions were mapped using the QDot catheter and then remapped using a Pentaray catheter. All QDot points were matched with Pentaray points within 5 mm. The swine were sacrificed, and mapping data projected onto the heart. Transmural biopsies corresponding to mapping points were obtained, allowing a comparison of electrograms recorded by mini, micro-, and conventional electrodes with histology.RESULTS The conventional BV of 2,322 QDot points was 1.9 +/- 1.3 mV. The largest of the 3 microelectrode BVs (BV mu Max) average 4.8 +/- 3.1 mV. The difference between the largest (BV mu Max) and smallest (BV mu Min) at a given location was 53.7 +/- 18.1%. The relationships between both BV mu Max and BV mu Min and between the conventional BV and BV mu Max were positively related but with a significant spread in data, which was more pronounced for the latter. Pentaray points positively related to the BV mu Max with poor fit. On histology, increasing viable myocardium increased voltage, but both the slope coefficient and fit were best for BV mu Max.CONCLUSIONS Using histology, we could demonstrate that BV mu Max is superior to identify viable myocardium compared with BVC and BV using the Pentaray catheter. The ability to simultaneously record 3 BV(mu)s with different orientations, for the same beat, with controllable contact and selecting BV mu Max for local BV may partially compensate for wave front direction. (C) 2021 by the American College of Cardiology Foundation.Cardiolog

    Application of a Serum Protein Signature for Pancreatic Cancer to Separate Cases from Controls in a Pancreatic Surveillance Cohort

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    BACKGROUND: Pancreatic cancer (PC) surveillance is currently offered to individuals with a genetic predisposition to PC, but routinely used radiological screening modalities are not entirely reliable in detecting early-stage PC or its precursor lesions. We recently identified a discriminating PC biomarker signature in a sporadic patient cohort. In this study, we investigated if protein profiling can accurately distinguish PC from non-PC in a pancreatic surveillance cohort of genetically predisposed individuals. METHODS: Serum samples of 66 individuals with a CDKN2A germline mutation who participated in the pancreatic surveillance program (5 cases, 61 controls) were obtained following a standardized protocol. After sample clean-up, peptide and protein profiles were obtained on an ultrahigh-resolution matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry platform. A discriminant score for each sample was calculated with a previously designed prediction rule, and the median discriminant scores of cases and controls were compared. Individuals with precursor lesions of PC (n = 4) and individuals with a recent diagnosis of melanoma (n = 4) were also separately considered. RESULTS: Cases had a higher median discriminant score than controls (0.26 vs 0.016; P = .001). The only individual with pathologically confirmed precursor lesions of PC could also be clearly distinguished from controls, and having a (recent) medical history of melanoma did not influence the protein signatures. CONCLUSIONS: Peptide and protein signatures are able to accurately distinguish PC cases from controls in a pancreatic surveillance setting. Mass spectrometry-based protein profiling therefore seems to be a promising candidate for implementation in the pancreatic surveillance program as an additional screening modality.Surgical oncolog

    Late follow-up of neo-aortic dimensions and coronary arteries in adult patients after the arterial switch operation

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    BackgroundAfter the arterial switch operation (ASO) for transposition of the great arteries (TGA), neo-aortic dilatation and coronary arterial anomalies, especially an interarterial course and acute coronary artery take-off angle, are commonly found. Long-term follow-up data after ASO is scarce. Aim of this study was to determine the prevalence of neo-aortic dilatation and coronary abnormalities, with special emphasis on acute coronary take-off angle, in adult TGA-ASO patients.MethodsIn this retrospective cohort study, all adult TGA-ASO patients with ≥1 CT-angiography (CTA) at the age of ≥16 years were included.ResultsEighty-one patients, 69 % male and median age 21.0 [18.5–22.8] years, were included. At baseline, maximum neo-aortic diameter was 39.2 ± 5.3 mm; 35 (43 %) patients had neo-aortic dilatation (neo-aortic diameter of >40 mm), 22 (27 %) patients had an acute coronary take-off angle (RCA (2 %) or LCA (4 %). Neo-aortic or coronary artery re-intervention occurred in 10 (12 %) patients. All 10 patients had neo-aortic dilatation or coronary take-off angle of ConclusionThis study reports a prevalence of 43 % of neo-aortic dilatation, 6 % of interarterial coronary course and 27 % for acute coronary take-off angle (40 mm or a coronary take-off angle of in patients with neo-aortic dilation and/or an acute angulation of Radiolog

    Sex differences in coronary plaque changes assessed by serial computed tomography angiography

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    Long-term data on sex-differences in coronary plaque changes over time is lacking in a low-to-intermediate risk population of stable coronary artery disease (CAD). The aim of this study was to evaluate the role of sex on long-term plaque progression and evolution of plaque composition. Furthermore, the influence of menopause on plaque progression and composition was also evaluated. Patients that underwent a coronary computed tomography angiography (CTA) were prospectively included to undergo a follow-up coronary CTA. Total and compositional plaque volumes were normalized using the vessel volume to calculate a percentage atheroma volume (PAV). To investigate the influence of menopause on plaque progression, patients were divided into two groups, under and over 55 years of age. In total, 211 patients were included in this analysis, 146 (69%) men. The mean interscan period between baseline and follow-up coronary CTA was 6.2 +/- 1.4 years. Women were older, had higher HDL levels and presented more often with atypical chest pain. Men had 434 plaque sites and women 156. On a per-lesion analysis, women had less fibro-fatty PAV compared to men (beta -1.3 +/- 0.4%; p < 0.001), with no other significant differences. When stratifying patients by 55 years age threshold, fibro-fatty PAV remained higher in men in both age groups (p < 0.05) whilst women younger than 55 years demonstrated more regression of fibrous (beta -0.8 +/- 0.3% per year; p = 0.002) and non-calcified PAV (beta -0.7 +/- 0.3% per year; p = 0.027). In a low-to-intermediate risk population of stable CAD patients, no significant sex differences in total PAV increase over time were observed. Fibro-fatty PAV was lower in women at any age and women under 55 years demonstrated significantly greater reduction in fibrous and non-calcified PAV over time compared to age-matched men. (ClinicalTrials.gov number, NCT04448691.)Cardiolog
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