27 research outputs found

    Excitation function shape and neutron spectrum of the Li 7 ( p , n ) Be 7 reaction near threshold

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    The forward-emitted low energy tail of the neutron spectrum generated by the 7Li(p,n)7Be^{7}\mathrm{Li}(p,n)^{7}\mathrm{Be} reaction on a thick target at a proton energy of 1893.6 keV was measured by time-of-flight spectroscopy. The measurement was performed at BELINA (Beam Line for Nuclear Astrophysics) of the Laboratori Nazionali di Legnaro. Using the reaction kinematics and the proton on lithium stopping power the shape of the excitation function is calculated from the measured neutron spectrum. Good agreement with two reported measurements was found. Our data, along with the previous measurements, are well reproduced by the Breit-Wigner single-resonance formula for ss-wave particles. The differential yield of the reaction is calculated and the widely used neutron spectrum at a proton energy of 1912 keV was reproduced. Possible causes regarding part of the 6.5% discrepancy between the ^{197}\mathrm{Au}(n,\ensuremath{\gamma}) cross section measured at this energy by Ratynski and Kappeler [Phys. Rev. C 37, 595 (1988)] and the one obtained using the Evaluated Nuclear Data File version B-VII.1 are given

    Management of Bleeding and Hemolysis During Percutaneous Microaxial Flow Pump Support A Practical Approach

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    © 2023 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Percutaneous ventricular assist devices (pVADs) are increasingly being used because of improved experience and availability. The Impella (Abiomed), a percutaneous microaxial, continuous-flow, short-term ventricular assist device, requires meticulous postimplantation management to avoid the 2 most frequent complications, namely, bleeding and hemolysis. A standardized approach to the prevention, detection, and treatment of these complications is mandatory to improve outcomes. The risk for hemolysis is mostly influenced by pump instability, resulting from patient- or device-related factors. Upfront echocardiographic assessment, frequent monitoring, and prompt intervention are essential. The precarious hemostatic balance during pVAD support results from the combination of a procoagulant state, due to critical illness and contact pathway activation, together with a variety of factors aggravating bleeding risk. Preventive strategies and appropriate management, adapted to the impact of the bleeding, are crucial. This review offers a guide to physicians to tackle these device-related complications in this critically ill pVAD-supported patient population.Peer reviewe

    Acute Delta Hepatitis in Italy spanning three decades (1991–2019): Evidence for the effectiveness of the hepatitis B vaccination campaign

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    Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p < .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p < .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come

    The role of immune suppression in COVID-19 hospitalization: clinical and epidemiological trends over three years of SARS-CoV-2 epidemic

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    Specific immune suppression types have been associated with a greater risk of severe COVID-19 disease and death. We analyzed data from patients >17 years that were hospitalized for COVID-19 at the “Fondazione IRCCS Ca′ Granda Ospedale Maggiore Policlinico” in Milan (Lombardy, Northern Italy). The study included 1727 SARS-CoV-2-positive patients (1,131 males, median age of 65 years) hospitalized between February 2020 and November 2022. Of these, 321 (18.6%, CI: 16.8–20.4%) had at least one condition defining immune suppression. Immune suppressed subjects were more likely to have other co-morbidities (80.4% vs. 69.8%, p < 0.001) and be vaccinated (37% vs. 12.7%, p < 0.001). We evaluated the contribution of immune suppression to hospitalization during the various stages of the epidemic and investigated whether immune suppression contributed to severe outcomes and death, also considering the vaccination status of the patients. The proportion of immune suppressed patients among all hospitalizations (initially stable at <20%) started to increase around December 2021, and remained high (30–50%). This change coincided with an increase in the proportions of older patients and patients with co-morbidities and with a decrease in the proportion of patients with severe outcomes. Vaccinated patients showed a lower proportion of severe outcomes; among non-vaccinated patients, severe outcomes were more common in immune suppressed individuals. Immune suppression was a significant predictor of severe outcomes, after adjusting for age, sex, co-morbidities, period of hospitalization, and vaccination status (OR: 1.64; 95% CI: 1.23–2.19), while vaccination was a protective factor (OR: 0.31; 95% IC: 0.20–0.47). However, after November 2021, differences in disease outcomes between vaccinated and non-vaccinated groups (for both immune suppressed and immune competent subjects) disappeared. Since December 2021, the spread of the less virulent Omicron variant and an overall higher level of induced and/or natural immunity likely contributed to the observed shift in hospitalized patient characteristics. Nonetheless, vaccination against SARS-CoV-2, likely in combination with naturally acquired immunity, effectively reduced severe outcomes in both immune competent (73.9% vs. 48.2%, p < 0.001) and immune suppressed (66.4% vs. 35.2%, p < 0.001) patients, confirming previous observations about the value of the vaccine in preventing serious disease

    40. Optical coherence tomography correlates of complex lesions evaluated by coronary angiography in patients with acute coronary syndromes

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    Plaque rupture (PR) and superimposed thrombosis have been shown as the most frequent underlying substrate in acute coronary syndromes (ACS). Coronary angiography is a luminogram that is not able to define in-vivo features of the culprit plaques. The aim of the study was to use optical coherence tomography (OCT) to investigate the pathology underlying complex (CL) and non-complex angiographic lesions (NCL). Methods: We retrospectively enrolled 107 ACS patients admitted to our institution; 83 with Non-ST elevation ACS (NSTE-ACS) and 24 with ST-elevation myocardial infarction (STEMI). Coronary angiography was performed and culprit lesions were classified according to Ambrose criteria into NCL (n = 47) and CL (n = 60). In STEMI patients, angiographic and OCT analysis were performed after mechanical thrombus aspiration. OCT analysis of these culprit lesion was performed to identify plaque morphology; either PR or intact fibrous cap (IFC), as well as the presence of superimposed thrombosis, lipid rich plaque, thin cap fibroatheroma (TCFA), and minimal lumen area (MLA). Results: OCT analysis showed that 58 lesions (54.2%) were classified as PR and 48 lesions (44.9%) were associated with thrombi. Lipid rich plaques were identified in 62 culprit plaques (57.9%). PR, intracoronary thrombi, lipid rich plaques and thin cap fibroatheroma (TCFA) were more frequent in CL compared with NCL (71.7% vs 31.9%, 63.3% vs 21.3%, 71.7% vs 40.4% and 46.7% vs 21.3% respectively). PR (31.9%) with superimposed thrombus (21.3%) may be also detected in NCL. In STEMI patients, there was no significant difference regarding OCT plaque features between NCL and CL. Conclusion: In conclusion, OCT demonstrates PR and thrombosis in the majority of ACS patients presenting with CL. Of note, one third of NCL has PR and thrombosis by OCT. In STEMI, coronary angiography is of limited utility in identifying PR by means of CL and should be implemented with OCT to tailor future therapies

    Protective effect of pre-infarction angina on microvascular obstruction after primary percutaneous coronary intervention is blunted in humans by cardiovascular risk factors

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    Pre-infarction angina (PIA) has been shown to reduce the microvascular obstruction (MVO) rate in patients with ST-segment elevation myocardial infarction (STEMI). We sought to evaluate the potential modulator role of cardiovascular risk factors (CRFs) on this protective effect

    Intra-Aortic Balloon Pumping in Acute Decompensated Heart Failure With Hypoperfusion: From Pathophysiology to Clinical Practice

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    Trials on intra-aortic balloon pump (IABP) use in cardiogenic shock related to acute myocardial infarction have shown disappointing results. The role of IABP in cardiogenic shock treatment remains unclear, and new (potentially more potent) mechanical circulatory supports with arguably larger device profile are emerging. A reappraisal of the physiological premises of intra-aortic counterpulsation may underpin the rationale to maintain IABP as a valuable therapeutic option for patients with acute decompensated heart failure and tissue hypoperfusion. Several pathophysiological features differ between myocardial infarction- and acute decompensated heart failure-related hypoperfusion, encompassing cardiogenic shock severity, filling status, systemic vascular resistances rise, and adaptation to chronic (if preexisting) left ventricular dysfunction. IABP combines a more substantial effect on left ventricular afterload with a modest increase in cardiac output and would therefore be most suitable in clinical scenarios characterized by a disproportionate increase in afterload without profound hemodynamic compromise. The acute decompensated heart failure syndrome is characterized by exquisite afterload-sensitivity of cardiac output and may be an ideal setting for counterpulsation. Several hemodynamic variables have been shown to predict response to IABP within this scenario, potentially guiding appropriate patient selection. Finally, acute decompensated heart failure with hypoperfusion may frequently represent an end stage in the heart failure history: IABP may provide sufficient hemodynamic support and prompt end-organ function recovery in view of more definitive heart replacement therapies while preserving ambulation when used with a transaxillary approach
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