120 research outputs found

    Analysis of transient seepage through a river embankment by means of centrifuge modelling

    Get PDF
    Earthen river embankments are typically in unsaturated conditions during their lifetime and the degree of saturation within their bodies may vary significantly throughout the year, due to seasonalfluctuations of the river stage, as well as infiltrations of meteoric precipitation and evapotranspiration phenomena. Given the significant effects of partial saturation on the hydro-mechanical behaviour of soils, realistic assumptions on the actual water content distribution inside the embankments are essential forproperly modelling their response to hydraulic loadings. In this framework, centrifuge modelling is a useful tool to get insights into the evolution of saturation conditions of a water retaining structure during flood events. It allows for the direct observation of the groundwater flow process, which is hardly detectable at the prototype scale, enabling, at the same time, the validation and calibration of predictive numerical tools.In this paper, the results of a centrifuge test carried out on small-scale physical model of a compacted silty clayey sand embankment subjected to a simulated high-water event, at the enhanced gravity of 50-g, are presented and discussed. The physical model was carefully instrumented with potentiometers, miniaturized pore pressure transducers and tensiometers. Pore pressures and suctions measured during the experiment showed that the stationary flow conditions were reached only after an unrealistic hydrometric peak persistence. It therefore emerges that, for the design and/or the assessment of the safety conditions of a river embankment similar to the one tested, the simplified hypothesis of a steady-state seepage, in equilibrium with the maximum river stage expected could result, in many cases, an excessively conservative assumption

    Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy: A Contemporary Reappraisal

    Get PDF
    Percutaneous alcohol septal ablation (ASA) is an effective and minimally invasive therapeutic strategy to resolve left ventricular outflow tract obstruction (LVOTO) in patients with hypertrophic cardiomyopathy who remain symptomatic on maximally tolerated medical therapy. First performed by Sigwart in 1994, the procedure consists in determining an iatrogenic infarction of the basal interventricular septum to reduce LVOTO and alleviate symptoms. Since its first description, numerous studies have demonstrated its efficacy and safety, proposing ASA as a valid and attractive alternative to surgical septal myectomy. The success rate of the intervention is profoundly affected by patient selection and centre experience. In this review, we sought to summarise current evidence on ASA, describing the procedure and proposing a cardiomyopathy team-based approach to resolve clinical disputes in clinical practice

    Dietary thiols: A potential supporting strategy against oxidative stress in heart failure and muscular damage during sports activity

    Get PDF
    Moderate exercise combined with proper nutrition are considered protective factors against cardiovascular disease and musculoskeletal disorders. However, physical activity is known not only to have positive effects. In fact, the achievement of a good performance requires a very high oxygen consumption, which leads to the formation of oxygen free radicals, responsible for premature cell aging and diseases such as heart failure and muscle injury. In this scenario, a primary role is played by antioxidants, in particular by natural antioxidants that can be taken through the diet. Natural antioxidants are molecules capable of counteracting oxygen free radicals without causing cellular cytotoxicity. In recent years, therefore, research has conducted numerous studies on the identification of natural micronutrients, in order to prevent or mitigate oxidative stress induced by physical activity by helping to support conventional drug therapies against heart failure and muscle damage. The aim of this review is to have an overview of how controlled physical activity and a diet rich in antioxidants can represent a “natural cure” to prevent imbalances caused by free oxygen radicals in diseases such as heart failure and muscle damage. In particular, we will focus on sulfur-containing compounds that have the ability to protect the body from oxidative stress. We will mainly focus on six natural antioxidants: Glutathione, taurine, lipoic acid, sulforaphane, garlic and methylsulfonylmethane

    Exercise, immune system, nutrition, respiratory and cardiovascular diseases during COVID-19: A complex combination

    Get PDF
    Coronaviruses (CoVs) represent a large family of RNA viruses that can infect different living species, posing a global threat to human health. CoVs can evade the immune response, replicate within the host, and cause a rapid immune compromise culminating in severe acute respiratory syndrome. In humans, the immune system functions are influenced by physical activity, nutrition, and the absence of respiratory or cardiovascular diseases. This review provides an in-depth study between the interactions of the immune system and coronaviruses in the host to defend against CoVs disease

    Prevalence and clinical significance of red flags in patients with hypertrophic cardiomyopathy

    Get PDF
    Introduction: We sought to determine prevalence and predictive accuracy of clinical markers (red flags, RF), known to be associated with specific systemic disease in a consecutive cohort of patients with hypertrophic cardiomyopathy (HCM). / Methods: We studied 129 consecutive patients (23.7 ± 20.9 years, range 0–74 years; male/female 68%/32%). Pre-specified RF were categorized into five domains: family history; signs/symptoms; electrocardiography; imaging; and laboratory. Sensitivity (Se), specificity (Sp), negative predictive value (NPV), positive predictive value (PPV), and predictive accuracy of RF were analyzed in the genotyped population. / Results: In the overall cohort of 129 patients, 169 RF were identified in 62 patients (48%). Prevalence of RF was higher in infants (78%) and in adults >55 years old (58%). Following targeted genetic and clinical evaluation, 94 patients (74%) had a definite diagnosis (sarcomeric HCM or specific causes of HCM). We observed 14 RF in 13 patients (21%) with sarcomeric gene disease, 129 RF in 34 patients (97%) with other specific causes of HCM, and 26 RF in 15 patients (45%) with idiopathic HCM (p  55yo. Se, Sp, PPV, NPV and PA of RF were 97%, 70%, 55%, 98% and 77%, respectively. Single and clinical combination of RF (clusters) had an high specificity, NPV and predictive accuracy for the specific etiologies (syndromes/metabolic/infiltrative disorders associated with HCM). / Conclusions: An extensive diagnostic work up, focused on analysis of specific diagnostic RF in patients with unexplained LVH facilitates a clinical diagnosis in 74% of patients with HCM

    Infarct size, inflammatory burden, and admission hyperglycemia in diabetic patients with acute myocardial infarction treated with SGLT2-inhibitors: a multicenter international registry

    Get PDF
    BACKGROUND: The inflammatory response occurring in acute myocardial infarction (AMI) has been proposed as a potential pharmacological target. Sodium-glucose co-transporter 2 inhibitors (SGLT2-I) currently receive intense clinical interest in patients with and without diabetes mellitus (DM) for their pleiotropic beneficial effects. We tested the hypothesis that SGLT2-I have anti-inflammatory effects along with glucose-lowering properties. Therefore, we investigated the link between stress hyperglycemia, inflammatory burden, and infarct size in a cohort of type 2 diabetic patients presenting with AMI treated with SGLT2-I versus other oral anti-diabetic (OAD) agents. METHODS: In this multicenter international observational registry, consecutive diabetic AMI patients undergoing percutaneous coronary intervention (PCI) between 2018 and 2021 were enrolled. Based on the presence of anti-diabetic therapy at the admission, patients were divided into those receiving SGLT2-I (SGLT-I users) versus other OAD agents (non-SGLT2-I users). The following inflammatory markers were evaluated at different time points: white-blood-cell count, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), neutrophil-to-platelet ratio (NPR), and C-reactive protein. Infarct size was assessed by echocardiography and by peak troponin levels. RESULTS: The study population consisted of 583 AMI patients (with or without ST-segment elevation): 98 SGLT2-I users and 485 non-SGLT-I users. Hyperglycemia at admission was less prevalent in the SGLT2-I group. Smaller infarct size was observed in patients treated with SGLT2-I compared to non-SGLT2-I group. On admission and at 24 h, inflammatory indices were significantly higher in non-SGLT2-I users compared to SGLT2-I patients, with a significant increase in neutrophil levels at 24 h. At multivariable analysis, the use of SGLT2-I was a significant predictor of reduced inflammatory response (OR 0.457, 95% CI 0.275-0.758, p = 0.002), independently of age, admission creatinine values, and admission glycemia. Conversely, peak troponin values and NSTEMI occurrence were independent predictors of a higher inflammatory status. CONCLUSIONS: Type 2 diabetic AMI patients receiving SGLT2-I exhibited significantly reduced inflammatory response and smaller infarct size compared to those receiving other OAD agents, independently of glucose-metabolic control. Our findings are hypothesis generating and provide new insights on the cardioprotective effects of SGLT2-I in the setting of coronary artery disease. TRIAL REGISTRATION: Data are part of the ongoing observational registry: SGLT2-I AMI PROTECT. CLINICALTRIALS: gov Identifier: NCT05261867

    Outcomes in diabetic patients treated with SGLT2-Inhibitors with acute myocardial infarction undergoing PCI: The SGLT2-I AMI PROTECT Registry

    Get PDF
    Aims: To investigate in-hospital and long-term prognosis in T2DM patients presenting with acute myocardial infarction (AMI) treated with SGLT2-I versus other oral anti-diabetic agents (non-SGLT2-I users). Methods: In this multicenter international registry all consecutive diabetic AMI patients undergoing percutaneous coronary intervention between 2018 and 2021 were enrolled and, based on the admission anti-diabetic therapy, divided into SGLT-I users versus non-SGLT2-I users. The primary endpoint was defined as a composite of cardiovascular death, recurrent AMI, and hospitalization for HF (MACE). Secondary outcomes included i) in-hospital cardiovascular death, recurrent AMI, occurrence of arrhythmias, and contrast-induced acute kidney injury (CI-AKI); ii) long-term cardiovascular mortality, recurrent AMI, heart failure (HF) hospitalization. Results: The study population consisted of 646 AMI patients (with or without ST-segment elevation): 111 SGLT2-I users and 535 non-SGLT-I users. The use of SGLT2-I was associated with a significantly lower in-hospital cardiovascular death, arrhythmic burden, and occurrence of CI-AKI (all p < 0.05). During a median follow-up of 24 ± 13 months, the primary composite endpoint, as well as cardiovascular mortality and HF hospitalization were lower for SGLT2-I users compared to non-SGLT2-I patients (p < 0.04 for all). After adjusting for confounding factors, the use of SGLT2-I was identified as independent predictor of reduced MACE occurrence (HR=0.57; 95%CI:0.33–0.99; p = 0.039) and HF hospitalization (HR=0.46; 95%CI:0.21–0.98; p = 0.041). Conclusions: In T2DM AMI patients, the use of SGLT2-I was associated with a lower risk of adverse cardiovascular outcomes during index hospitalization and long-term follow-up. Our findings provide new insights into the cardioprotective effects of SGLT2-I in the setting of AMI. Registration: Data are part of the observational international registry: SGLT2-I AMI PROTECT. ClinicalTrials.gov Identifier: NCT05261867
    • …
    corecore