Observation of Collider Muon Neutrinos with the SND@LHC Experiment.

We report the direct observation of muon neutrino interactions with the SND@LHC detector at the Large Hadron Collider. A dataset of proton-proton collisions at sqrt[s]=13.6 TeV collected by SND@LHC in 2022 is used, corresponding to an integrated luminosity of 36.8 fb^{-1}. The search is based on information from the active electronic components of the SND@LHC detector, which covers the pseudorapidity region of 7.2<η<8.4, inaccessible to the other experiments at the collider. Muon neutrino candidates are identified through their charged-current interaction topology, with a track propagating through the entire length of the muon detector. After selection cuts, 8 ν_{µ} interaction candidate events remain with an estimated background of 0.086 events, yielding a significance of about 7 standard deviations for the observed ν_{µ} signal.

Spin-dependent electron-proton scattering in the Delta-excitation region.

We report on measurements of the cross section and provide first data on spin correlation parameters A(TT') and A(TL') in inclusive scattering of longitudinally polarized electrons from nuclear-polarized hydrogen. Polarized electrons were injected into an electron storage ring operated at a beam energy of 720 MeV. Polarized hydrogen was produced by an atomic beam source and injected into an open-ended cylindrical cell, located in the electron storage ring. The four-momentum transfer squared ranged from Q2 = 0.2 GeV(2)/c(2) at the elastic scattering peak to Q2 = 0.11 GeV(2)/c(2) at the Delta(1232) resonance. The data provide a stringent test of pion electroproduction models.

Spin-momentum correlations in quasielastic electron scattering from deuterium.

The spin-momentum correlation parameter A(V)(ed) was measured for the 2H-->(e-->,e'p)n reaction for missing momenta up to 350 MeV/c at Q2 = 0.21 (GeV/c)(2) for quasielastic scattering of polarized electrons from vector-polarized deuterium. The data give detailed information about the deuteron spin structure and are in good agreement with the results of microscopic calculations based on realistic nucleon-nucleon potentials and including various spin-dependent reaction mechanism effects. The experiment reveals in a most direct manner the effects of the D state in the deuteron ground-state wave function and shows the importance of isobar configurations for this reaction.

Experiments with longitudinally polarized electrons in a storage ring using a siberian snake

We report on first measurements with polarized electrons stored in a medium-energy ring and with a polarized internal target. Polarized electrons were injected at 442 MeV (653 MeV), and a partial (full) Siberian snake was employed to preserve the polarization. Longitudinal polarization at the interaction point and polarization lifetime of the stored electrons were determined with laser backscattering. Spin observables were measured for electrodisintegration of polarized 3He, with simultaneous detection of scattered electrons, protons, neutrons, deuterons, and 3He nuclei, over a large phase space.

Assessment of diastolic left ventricular filling by echocardiographic automated border detection and comparison with radionuclide ventriculography.

To determine whether indexes obtained from a newly developed echocardiographic automated border detection (ABD) technology provide a reliable estimate of left ventricular (LV) diastolic filling, ABD variables of LV filling were compared with volumetric measurements determined by radionuclide angiography. Forty-two patients with a variety of heart diseases (age range, 11 to 76 years) underwent ABD echocardiographic studies on the same day as the radionuclide examination. Technically adequate ABD data could be obtained in 31 patients (74%). Nineteen healthy subjects served as normal controls. Area-time and volume-time waveforms for echocardiographic measurements were obtained from LV short-axis views at the level of the papillary muscles and four-chamber apical views. Both the diastolic indexes derived from the waveform of area change (short-axis view) and volume change (four-chamber apical view) correlated with radionuclide variables. Values measured from the ABD area-time waveform showed the following correlations: peak filling rate (r = 0.86; standard error of the estimate [SEE] = 0.62), time to peak filling rate (r = 0.85; SEE = 23.11), rapid filling phase fractional change (r = 0.79; SEE = 5.51), and atrial filling phase fractional change (r = 0.71; SEE = 5.82). Correlations of indexes derived from the ABD volume-time waveform were as follows: peak filling rate (r = 0.87; SEE = 0.50), time to peak filling rate (r = 0.90; SEE = 22.03), rapid filling fractional change (r = 0.83; SEE = 5.33), and atrial filling fractional change (r = 0.77; SEE = 4.68). ABD LV filling parameters in patients with heart disease and normal control subjects were significantly different. Thus ABD data from short-axis and apical views have a strong linear relation with radionuclide ventriculographic measurements and may be used as a method to assess LV diastolic filling.

Identification of viable myocardium in patients with chronic coronary artery disease and left ventricular dysfunction: role of magnetic resonance imaging.

Nineteen patients (16 men and 3 women, mean age 51 years) with previous anterior myocardial infarction and severe stenosis (> or = 90%) of the left anterior descending coronary artery were studied by magnetic resonance imaging (MRI) without and with contrast media to verify the capability of MRI in identifying viable myocardium in areas of severe systolic dysfunction. In corresponding left ventricular segments, a comparison was made between regional signal intensities (SI) determined on MRI images before and 4, 8, 12, and 30 minutes after administration of paramagnetic contrast media (gadolinium diethylenetriaminepentaacetic acid, 0.4 mmol/kg intravenously) and metabolic parameters determined by iodine 123 phenylpentadecanoic acid (IPPA) scintigraphy. The SI and the time of maximum postcontrast enhancement were analyzed by dividing the left ventricle into 11 segments. Each segment was classified as normal (group 1, n = 116), hibernating (group 2, n = 50), or necrotic (group 3, n = 43) on the basis of the IPPA washout rate (> 30%, 10% to 30%, and < 10%, respectively). Regional SI demonstrated significant differences in absolute values at 12 minutes (group 3: 1.62 +/- 0.58 vs group 1: 1.32 +/- 0.52, p < 0.01, and vs group 2: 1.34 +/- 0.48, p < 0.05) and at 30 minutes (group 3: 1.71 +/- 0.47 vs group 1: 1.21 +/- 0.55, p < 0.01, and vs group 2: 1.49 +/- 0.57, p < 0.05) and in temporal distribution. These results suggest that MRI has a potential role in differentiating viable from necrotic myocardium in patients with chronic severe systolic dysfunction.

[The variability of the heart rate in patients with a myocardial infarct undergoing systemic fibrinolysis interventions]. / Variabilità della frequenza cardiaca in pazienti con infarto miocardico sottoposti ad interventi di fibrinolisi per via sistemica.

Although heart rate variability is a very important prognostic factor in patients with myocardial infarction, the mechanism for the reduction in the vagal cardiac activity is unknown: myocardial infarction can cause local areas of sympathetic or parasympathetic denervation that leads to catecholamine hypersensitivity; the destruction of local ventricular receptors of the autonomic system may alter feedback to the higher centres, impairing autonomic regulation; the mechanical distortion consequent to the infarction can give rise to sympathetic overactivity. Effective thrombolysis in myocardial infarction could reduce myocardial necrosis and, therefore, cause less reduction of vagal activity and/or less sympathetic stimulation. To determine whether systemic thrombolysis has some effect on heart rate variability we studied 40 patients with a first transmural myocardial infarction. Enrollment criteria were very strict: all the patients with conditions potentially influencing heart rate variability were excluded from this study. Between day 15 and day 25 from the infarction patients had an Holter monitoring. A program we developed provided for the automatic identification of R wave, for the calculation of RR interval, and for the recognition of pause, extrasystolic and post-extrasystolic beats, that could be thus excluded from the analysis. Patients were divided in 2 groups: 17 patients treated with thrombolysis and 23 subjects treated traditionally. There were no difference between the 2 groups with regard to the age and cardiac function, except for the less echo score in the fibrinolytic treated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Equilibrium radionuclide ventriculography in Duchenne's cardiomyopathy.

Rest and stress (handgrip) equilibrium radionuclide ventriculography was performed in 20 patients with Duchenne muscular dystrophy. The mean value of LVEF was normal, but two patients showed values below 35% and another two patients values over 70%. Mean regional wall motion values were less than 2 in lateral (posterior and inferior) and septal walls. Handgrip usually produced a reduction of LVEF and regional wall motion: in three cases severe decrease of motility was observed. Equilibrium ventriculography appears to be useful in the selection of patients with high functional cardiac involvement, integrating the characteristic ECG and echography, and, perhaps, in the assessment of myocardial tolerance to physical therapy.

Some aspects of the pathophysiology of hypertrophic cardiopathies. An echocardiographic computerized study.

35 patients, of them 10 with aortic stenosis, 7 with idiopathic hypertrophic subaortic stenosis, 6 with asymmetric septal hypertrophy, and 12 with systemic hypertension were examined with the aim of a pathophysiological differentiation of various hypertrophic cardiopathies. The authors' own ECE digital echocardiographic system was used. The results attest to an abnormal diastolic function in hypertrophic cardiopathies. At the same time, the diastolic compliance is less affected in symmetric cardiopathies, even in their more advanced clinical stage, than in asymmetric ones.