16 research outputs found

    Atypical Presentation of Acute Coronary Syndrome-Not ST Elevation: A Case Report

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    We describe the unexpected case of a 70-year-old man, with medical history of ischemic heart disease and surgery for aneurysm of abdominal aorta, who comes to the emergency department complaining of low-back pain without other symptoms or signs of organic failure. After a few hours we see a deterioration of physical conditions with pulmonary oedema, increase of blood pressure, changing in the ECG pattern, and worsening of left ventricular function with progressive increase of biomarkers for myocardial necrosis. So this pain has revealed the premature symptom of an acute coronary syndrome (ACS). After a short time a subsequent cardiac arrest complicates the clinical situation. After resuscitation, the patient undergoes successfully to coronary angiography and performed a percutaneous transluminal coronary angioplasty (PTCA)

    Zero Fluoroscopy Arrhythmias Catheter Ablation: A Trend Toward More Frequent Practice in a High-Volume Center

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    BACKGROUND: Awareness of radiation exposure risks associated to interventional cardiology procedures is growing. The availability of new technologies in electrophysiology laboratories has reduced fluoroscopy usage during arrhythmias ablations. The aim of this study was to describe procedures with and without X-Rays and to assess feasibility, safety, and short-term efficacy of zero fluoroscopy intervention in a high-volume center oriented to keep exposure to ionizing radiation as low as reasonably achievable. METHODS: Cardiac catheter ablations performed in our hospital since January 2017 to June 2021. RESULTS: A total of 1,853 procedures were performed with 1,957 arrhythmias treated. Rate of fluoroless procedures was 15.4% (285 interventions) with an increasing trend from 8.5% in 2017 to 22.9% of first semester 2021. The most frequent arrhythmia treated was atrial fibrillation (646; 3.6% fluoroless) followed by atrioventricular nodal reentrant tachycardia (644; 16.9% fluoroless), atrial flutter (215; 8.8% fluoroless), ventricular tachycardia (178; 17.4% fluoroless), premature ventricular contraction (162; 48.1% fluoroless), and accessory pathways (112; 31.3% fluoroless). Although characteristics of patients and operative details were heterogeneous among treated arrhythmias, use of fluoroscopy did not influence procedure duration. Moreover, feasibility and efficacy were 100% in fluoroless ablations while the rate of major complications was very low and no different with or without fluoroscopy (0.45 vs. 0.35%). CONCLUSION: Limiting the use of X-Rays is necessary, especially when the available technologies allow a zero-use approach. A lower radiation exposure may be reached, reducing fluoroscopy usage whenever possible during cardiac ablation procedures with high safety, full feasibility, and efficacy

    Normalized compression distance to measure cortico-muscular synchronization

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    The neuronal functional connectivity is a complex and non-stationary phenomenon creating dynamic networks synchronization determining the brain states and needed to produce tasks. Here, as a measure that quantifies the synchronization between the neuronal electrical activity of two brain regions, we used the normalized compression distance (NCD), which is the length of the compressed file constituted by the concatenated two signals, normalized by the length of the two compressed files including each single signal. To test the NCD sensitivity to physiological properties, we used NCD to measure the cortico-muscular synchronization, a well-known mechanism to control movements, in 15 healthy volunteers during a weak handgrip. Independently of NCD compressor (Huffman or Lempel Ziv), we found out that the resulting measure is sensitive to the dominant-non dominant asymmetry when novelty management is required (p = 0.011; p = 0.007, respectively) and depends on the level of novelty when moving the nondominant hand (p = 0.012; p = 0.024). Showing lower synchronization levels for less dexterous networks, NCD seems to be a measure able to enrich the estimate of functional two-node connectivity within the neuronal networks that control the body

    Equilibrium and dissipative structures role on images

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    This paper introduces entropy as a feature for 1D signals. We propose as entropy measure the ratio between the signal's perturbation (i.e. its part within minimum and maximum grey level) and the total energy of the signal. A linear transformation of 2D signals into 1D signals is also illustrated together with the results concerning natural scene, texture and medical images from a large mammograms database. The aim of this paper is to verify if the entropy variations for a closed system can be a discriminant feature to select homogenous regions. © 2007 Elsevier B.V. All rights reserved

    Dielectric Micro‐ and Sub‐Micrometric Spacers for High‐Temperature Energy Converters

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    Dielectric microspacers (DMS) are important components in thermal energy converters. Engineered DMS are fabricated and characterized on different substrates by depositing patterned ceramic thin films of alumina (Al2O3) and zirconia (ZrO2) with a thickness ranging from 0.3 to 3 mu m. Both Al2O3 and ZrO2 films are electrically and thermally optimized, finding zirconia more suitable as a thermal and electrical insulating material at high temperature, whereas the developed DMS are morphologically analyzed by scanning electron microscopy. The analysis of thermal simulations carried out with COMSOL Multiphysics allows identifying the best geometrical constraints for each single structure, whereas simulations carried out by the Fluent software allow identifying the best arrangement for DMS, leading to a solution with optimized pattern in terms of amount and spatial distribution so to achieve the required electrical and thermal insulation for practical applications. DMS are integrated within thermionic-photovoltaic devices to be validated experimentally, and enhanced electron emission measurements are successfully performed at a cathode temperature up to 1350 degrees C to verify the operational feasibility and potential of this technology

    Variation in wing morphology is related to breeding environment in a high-elevation specialist bird

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    Abstract The morphology of bird wings is subject to a variety of selective pressures, including migration, predation, habitat structure and sexual selection. Variation in wing morphology also occurs at the intraspecific and intrapopulation level, and can be related to sex, age, migration strategy and environmental factors. The relationship between environment and intraspecific variation in wing morphology is still poorly understood. In this work, we studied the relationship between wing morphology and breeding environment in a high-elevation specialist bird, the water pipit Anthus spinoletta. We calculated wing isometric size, pointedness and convexity of 84 birds mist-netted at breeding sites in year 2021 in the European Alps. We then searched for associations between these traits and potentially relevant breeding site characteristics (vegetation structure, elevation, latitude). For all wing traits, sex and one or more environmental factors best explained the variation, with environmental factors explaining between 3 and 8% of the variation. Wing size was negatively related to tree cover and wing convexity was negatively related to bush cover. Elevation contributed to explain variation in wing pointedness, but the direction of its effect was unclear. The negative relationship between wing size and tree cover could be due to intraspecific competition, i.e. to the relegation of smaller winged low-quality individuals in marginal grassland areas. Higher wing convexity could improve predator escape ability in areas with scarce protecting vegetation, with possible effects on habitat choice. These findings represent one of the few demonstrated cases of wing morphology–environment relationships at the intraspecific level
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