3,701 research outputs found

    The value of multi-slice-computed tomography coronary angiography for risk stratification

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    Multi-slice-computed tomography coronary angiography (CTA) provides direct non-invasive anatomic assessment of the coronary arteries allowing for early identification of coronary artery disease (CAD). This information is useful for diagnosis of CAD, particularly the rule out of CAD. In addition, early identification of CAD with CTA may also be useful for risk stratification. The purpose of this review is to provide an overview of the current literature on the prognostic value of CTA and to discuss how the prognostic information obtained with CTA can be used to further integrate the technique into clinical practice. Non-invasive anatomic assessment of plaque burden, location, composition, and remodeling using CTA may provide prognostically relevant information. This information has been shown to be incremental to the Framingham risk score, coronary artery calcium scoring, and myocardial perfusion imaging. Characterization of atherosclerosis non-invasively has the potential to provide important prognostic information enabling a more patient-tailored approach to disease management. Future studies assessing outcome after CTA-based risk adjustments are needed to further understand the value of detailed non-invasive anatomic imaging

    A System of ODEs for Representing Trends of CGM Signals

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    Diabetes Mellitus is a metabolic disorder which may result in severe and potentially fatal complications if not well-treated and monitored. In this study, a quantitative analysis of the data collected using CGM (Continuous Glucose Monitoring) devices from eight subjects with type 2 diabetes in good metabolic control at the University Polyclinic Agostino Gemelli, Catholic University of the Sacred Heart, was carried out. In particular, a system of ordinary differential equations whose state variables are affected by a sequence of stochastic perturbations was proposed and used to extract more informative inferences from the patients' data. For this work, Matlab and R programs were used to find the most appropriate values of the parameters (according to the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC)) for each patient. Fitting was carried out by Particle Swarm Optimization to minimize the ordinary least squares error between the observed CGM data and the data from the ODE model. Goodness of fit tests were made in order to assess which probability distribution was best suitable for representing the waiting times computed from the model parameters. Finally, both parametric and non-parametric density estimation of the frequency histograms associated with the variability of the glucose elimination rate from blood were conducted and their representative parameters assessed from the data. The results show that the chosen models succeed in capturing most of the glucose fluctuations for almost every patient

    Cardiac Sympathetic Denervation in Channelopathies

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    Left cardiac sympathetic denervation (LCSD) is a surgical antiadrenergic intervention with a strong antiarrhythmic effect, supported by preclinical as well as clinical data. The mechanism of action of LCSD in structurally normal hearts with increased arrhythmic susceptibility (such as those of patients with channelopathies) is not limited to the antagonism of acute catecholamines release in the heart. LCSD also conveys a strong anti-fibrillatory action that was first demonstrated over 40 years ago and provides the rationale for its use in almost any cardiac condition at increased risk of ventricular fibrillation. The molecular mechanisms involved in the final antiarrhythmic effect of LCSD turned out to be much broader than anticipated. Beside the vagotonic effect at different levels of the neuraxis, other new mechanisms have been recently proposed, such as the antagonism of neuronal remodeling, the antagonism of neuropeptide Y effects, and the correction of neuronal nitric oxide synthase (nNOS) imbalance. The beneficial effects of LCSD have never been associated with a detectable deterioration of cardiac performance. Finally, patients express a high degree of satisfaction with the procedure. In this review, we focus on the rationale, results and our personal approach to LCSD in patients with channelopathies such as long QT syndrome and catecholaminergic polymorphic ventricular tachycardia

    Capacity for the management of kidney failure in the International Society of Nephrology Western Europe region:Report from the 2023 ISN Global Kidney Health Atlas (ISN-GKHA)

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    Western Europe boasts advanced healthcare systems, robust kidney care guidelines, and a well-established healthcare workforce. Despite this, significant disparities in kidney replacement therapy incidence, prevalence, and transplant access exist. This paper presents the third International Society of Nephrology Global Kidney Health Atlas’s findings on kidney care availability, accessibility, affordability, and quality in 22 Western European countries, representing 99% of the region's population. The known chronic kidney disease (CKD) prevalence across Western Europe averages 10.6%, slightly above the global median. Cardiovascular diseases account for a substantial portion of CKD-related deaths. Kidney failure incidence varies. Government health expenditure differs, however, most countries offer government-funded acute kidney injury, dialysis, and kidney transplantation care. Hemodialysis and peritoneal dialysis are universally available, with variations in the number of dialysis centers. Kidney transplantation is available in all countries (except for three microstates), with variable transplant center prevalence. Conservative kidney management is increasingly accessible. The region's kidney care workforce is substantial, exceeding global averages, however, workforce shortages are reported. Barriers to optimal kidney care include limited workforce capacity, lack of surveillance mechanisms, and suboptimal integration into national non-communicable disease strategies. Policy recognition of CKD as a health priority varies across countries. While Western Europe exhibits strong kidney care infrastructure, opportunities for improvement exist, particularly in CKD prevention, surveillance, awareness, and policy implementation. Efforts to improve CKD care should include automated detection, educational support, and enhanced workflows. Based on these findings, healthcare professionals, stakeholders, and policymakers are called to act to enhance kidney care across the region

    Rapid assessment of nonlinear optical propagation effects in dielectrics

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    8 págs.; 6 figs.; Open Access funded by Creative Commons Atribution Licence 4.0Ultrafast laser processing applications need fast approaches to assess the nonlinear propagation of the laser beam in order to predict the optimal range of processing parameters in a wide variety of cases. We develop here a method based on the simple monitoring of the nonlinear beam shaping against numerical prediction. The numerical code solves the nonlinear Schrodinger equation with nonlinear absorption under simplified conditions by employing a state-of-the art computationally efficient approach. By comparing with experimental results we can rapidly estimate the nonlinear refractive index and nonlinear absorption coefficients of the material. The validity of this approach has been tested in a variety of experiments where nonlinearities play a key role, like spatial soliton shaping or fs-laser waveguide writing. The approach provides excellent results for propagated power densities for which free carrier generation effects can be neglected. Above such a threshold, the peculiarities of the nonlinear propagation of elliptical beams enable acquiring an instantaneous picture of the deposition of energy inside the material realistic enough to estimate the effective nonlinear refractive index and nonlinear absorption coefficients that can be used for predicting the spatial distribution of energy deposition inside the material and controlling the beam in the writing process.This work has been partly funded by MINECO TEC2011-22422 project. J. de H. acknowledges funding from the JAE CSIC Program (pre-doctoral fellowship co-funded by the European Social Fund). A.P. acknowledges support from the People Program (Marie Curie Actions) Incoming International Fellowship (CHRONOS) under REA grant agreement nu [327627].Peer Reviewe

    Cerebral hemodynamics during atrial fibrillation: computational fluid dynamics (CFD) analysis of lenticulostriate arteries using 7T high-resolution magnetic resonance imaging

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    Atrial fibrillation (AF) is the most common cardiac arrhythmia, inducing irregular and faster heart beating. Aside from disabling symptoms - such as palpitations, chest discomfort, and reduced exercise capacity - there is growing evidence that AF increases the risk of dementia and cognitive decline, even in the absence of clinical strokes. Among the possible mechanisms, the alteration of deep cerebral hemodynamics during AF is one of the most fascinating and least investigated hypotheses. Lenticulostriate arteries (LSAs) - small perforating arteries perpendicularly departing from the anterior and middle cerebral arteries and supplying blood flow to basal ganglia - are especially involved in silent strokes and cerebral small vessel diseases, which are considered among the main vascular drivers of dementia. We propose for the first time a computational fluid dynamics analysis to investigate the AF effects on the LSAs hemodynamics by using 7 T high-resolution magnetic resonance imaging (MRI). We explored different heart rates (HRs) - from 50 to 130 bpm - in sinus rhythm and AF, exploiting MRI data from a healthy young male and internal carotid artery data from validated 0D cardiovascular-cerebral modeling as inflow condition. Our results reveal that AF induces a marked reduction of wall shear stress and flow velocity fields. This study suggests that AF at higher HR leads to a more hazardous hemodynamic scenario by increasing the atheromatosis and thrombogenesis risks in the LSAs region
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