1,721,339 research outputs found
Letter regarding article by Solomon et al, "Cardiac Angiography in REnally Impaired Patients (CARE) study: a randomized double-blind trial of contrast-induced nephropathy in patients with chronic kidney disease".
No full textCorrection: Creation of Side-to-Side Compression Anastomosis Using the GT Metabolic SolutionsTM Magnet System, DI Biofragmentable (MagDITM System) to Achieve Duodeno-Ileal Diversion in Patients with Obesity: Preliminary Italian Multi-Center Results (Obesity Surgery, (2025), 10.1007/s11695-025-08409-z)
No full textIn the published article there is an error in the name of the fourth author. The correct name is Giovanni Cesana
Transverse single spin asymmetries in Drell-Yan processes
No full textRecently, it has been shown, contrary to previous beliefs, that the k(perp)-distribution of quarks in a transversely polarized proton can be asymmetric. This "Sivers effect" had already been used to explain transverse single spin asymmetry (SSA) observed in inclusive pion production p(uparrow) p --> pi X and pbar(uparrow) p --> pi X. In such channels, however, other mechanisms, such as the "Collins effect" (a k(perp)-asymmetric fragmentation of a transversely polarized quark into pions), may generate SSA. The Sivers asymmetry is used here to compute the SSA in Drell-Yan processes; in this case, by considering the differential cross section in the lepton-pair invariant mass, rapidity, and transverse momentum, other mechanisms that may originate SSA cannot contribute. Estimates for BNL RHIC experiments are given
L. Anselmino, M. Bouchenaki, A. Carandini, Ph. Leveau, D. Manacorda, C. Pavolini, G. Pucci, P. SalamA (premessa di A. Di Vita), Il castellum del Nador, Storia di una fattoria tra Tipasa e Caesarea (Ie- VIe s.)
No full textDuval Noël. L. Anselmino, M. Bouchenaki, A. Carandini, Ph. Leveau, D. Manacorda, C. Pavolini, G. Pucci, P. SalamA (premessa di A. Di Vita), Il castellum del Nador, Storia di una fattoria tra Tipasa e Caesarea (Ie- VIe s.). In: Bulletin Monumental, tome 148, n°3, année 1990. pp. 328-330
L. Anselmino, M. Bouchenaki, A. Carandini, Ph. Leveau, D. Manacorda, C. Pavolini, G. Pucci, P. SalamA (premessa di A. Di Vita), Il castellum del Nador, Storia di una fattoria tra Tipasa e Caesarea (Ie- VIe s.)
No full textDuval Noël. L. Anselmino, M. Bouchenaki, A. Carandini, Ph. Leveau, D. Manacorda, C. Pavolini, G. Pucci, P. SalamA (premessa di A. Di Vita), Il castellum del Nador, Storia di una fattoria tra Tipasa e Caesarea (Ie- VIe s.). In: Bulletin Monumental, tome 148, n°3, année 1990. pp. 328-330
Impaired coronary blood flow at higher heart rates during atrial fibrillation: Investigation via multiscale modelling
Full text linkBackground
Different mechanisms have been proposed to relate atrial fibrillation (AF) and coronary flow impairment, even in absence of relevant coronary artery disease (CAD). However, the underlying hemodynamics remains unclear. Aim of the present work is to computationally explore whether and to what extent ventricular rate during AF affects the coronary perfusion.
Methods
AF is simulated at different ventricular rates (50, 70, 90, 110, 130 bpm) through a 0D-1D multiscale validated model, which combines the left heart-arterial tree together with the coronary circulation. Artificially-built RR stochastic extraction mimics the in vivo beating features. All the hemodynamic parameters computed are based on the left anterior descending (LAD) artery and account for the waveform, amplitude and perfusion of the coronary blood flow.
Results
Alterations of the coronary hemodynamics are found to be associated either to the heart rate increase, which strongly modifies waveform and amplitude of the LAD flow rate, and to the beat-to-beat variability. The latter is overall amplified in the coronary circulation as HR grows, even though the input RR variability is kept constant at all HRs.
Conclusions
Higher ventricular rate during AF exerts an overall coronary blood flow impairment and imbalance of the myocardial oxygen supply-demand ratio. The combined increase of heart rate and higher AF-induced hemodynamic variability lead to a coronary perfusion impairment exceeding 90–110 bpm in AF. Moreover, it is found that coronary perfusion pressure (CPP) is no longer a good measure of the myocardial perfusion for HR higher than 90 bpm
Calorimetric analysis of ice onset temperature during cryoablation: a model approach to identify early predictors of effective applications
Full text linkAim of the present study is to analyze thermal events occurring during cryoablation. Different bovine liver samples underwent freezing cycles at different cooling rate (from 0.0075 to 25 K/min). Ice onset temperature and specific latent heat capacity of the ice formation process were measured according to differential scanning calorimetry signals. A computational model of the thermal events occurring during cryoablation was compiled using Neumann’s analytical solution. Latent heat (#1 = 139.8 ± 7.4 J/g, #2 = 147.8 ± 7.9 J/g, #3 = 159.0 ± 4.1 J/g) of all liver samples was independent of the ice onset temperature, but linearly dependent on the water content. Ice onset temperature was proportional to the logarithm of the cooling rate in the range 5 ÷ 25 K/min (#3a = − 12.2 °C, #3b = − 16.2 °C, #3c = − 6.6 °C at 5K/min; #3a = − 16.5 °C, #3b = − 19.3 °C, #3c = − 11.6 °C at 25 K/min). Ice onset temperature was associated with both the way in which the heat involved into the phase transition was delivered and with the thermal gradient inside the tissue. Ice onset temperature should be evaluated in the early phase of the ablation to tailor cryoenergy delivery. In order to obtain low ice trigger temperatures and consequent low ablation temperatures a high cooling rate is necessary
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