248 research outputs found
Watertight low-cost electrical connector
Fabrication is described of waterproof electrical connector assembly for use with Teflon jacketed cables and constructed so that assembly will remain sealed under extreme environmental conditions. Conditions are specified as: pressure from vacuum to atmospheric; temperature from 280 K to 450 K; exposure to saturated steam; and steam suddenly introduced into vacuum
Bose-Einstein Condensation in the Framework of -Statistics
In the present work we study the main physical properties of a gas of
-deformed bosons described through the statistical distribution
function . The
deformed -exponential , recently proposed in Ref.
[G.Kaniadakis, Physica A {\bf 296}, 405, (2001)], reduces to the standard
exponential as the deformation parameter , so that
reproduces the Bose-Einstein distribution. The condensation temperature
of this gas decreases with increasing value, and
approaches the transition temperature
, improving the result obtained in the standard case
(). The heat capacity is a continuous function and
behaves as for , in
contrast with the standard case , it is always increasing.
Pacs: 05.30.Jp, 05.70.-a Keywords: Generalized entropy; Boson gas; Phase
transition.Comment: To appear in Physica B. Two fig.p
The burden of calcific aortic stenosis. what's behind
In Western countries, calcific aortic valve stenosis (CAS) is widely common, representing the third cause of death among cardiovascular diseases (CVD). The burden of CAS is high, with an increasing prevalence rate related to age. An efficient medical treatment, according to guidelines, lacks to prevent the development and to reduce the progression of CAS. In this context, due to the aging population and the lack of effective medical management, the prevalence is expected to double-triple within the next decades. In our review, we aim to provide an overview of the underlying mechanisms of pathogenesis and the current state of the art regarding pathophysiological insights and novel potential therapeutic targets
Functional Tricuspid Regurgitation: Behind the Scenes of a Long-Time Neglected Disease
Severe tricuspid valve regurgitation has been for a long time a neglected valve disease, which has only recently attracted an increasing interest due to the notable negative impact on the prognosis of patients with cardiovascular disease. It is estimated that around 90% of tricuspid regurgitation is diagnosed as "functional" and mostly secondary to a primary left-sided heart disease and, therefore, has been usually interpreted as a benign condition that did not require a surgical management. Nevertheless, the persistence of severe tricuspid regurgitation after left-sided surgical correction of a valve disease, particularly mitral valve surgery, has been associated to adverse outcomes, worsening of the quality of life, and a significant increase in mortality rate. Similar results have been found when the impact of isolated severe tricuspid regurgitation has been studied. Current knowledge is shifting the "functional" categorization toward a more complex and detailed pathophysiological classification, identifying various phenotypes with completely different etiology, natural history and, potentially, an invasive management. The aim of this review is to offer a comprehensive guide for clinicians and surgeons with a systematic description of "functional" tricuspid regurgitation subtypes, an analysis centered on the effectiveness of existing surgical techniques and a focus on the emergent percutaneous procedures. This latter may be an attractive alternative to a standard surgical approach in patients with high-operative risk or isolated tricuspid regurgitation.Copyright © 2022 Vinciguerra, Sitges, Luis Pomar, Romiti, Domenech-Ximenos, D'Abramo, Wretschko, Miraldi and Greco
Comparative indoor pollution from Glo, Iqos, and Juul, using traditional combustion cigarettes as benchmark. Evidence from the randomized sur-vapes air trial
Modified risk products (MRP) such as electronic vaping cigarettes (EVC) and heat-not-burn cigarettes (HNBC) are appealing alternatives to combustion cigarettes. Limited between-and within-device comparative data are available on MRP. We aimed at comparing indoor particulate matter (PM) emissions measured in a randomized trial enforcing standardized smoking sessions, testing different devices and flavors of MRP, using traditional combustion cigarettes (TCC) as benchmark. Overall, MRP yielded significantly lower levels of indoor PM in comparison to TCC (with median PM levels during smoking for MRP < 100 ”g/m3, and for TCC > 1000 ”g/m3). Despite this, significant differences among MRP were found, with Iqos appearing associated with a significantly lower burden of emissions for all the monitored fractions of PM, including total PM (all p < 0.05). Precisely, during use, PM †1 ”m (PM1) emissions were 28 (16; 28) ”g/m3 for Glo, 25 (15; 57) ”g/m3 for Iqos, and 73 (15; 559) ”g/m3 for Juul (p < 0.001 for Glo vs. Iqos, p <0.001 for Glo vs. Juul, and p = 0.045 for Iqos vs. Juul). Exploratory within-MRP analyses suggested significant differences between flavors, favoring, for instance, Ultramarine for Glo, Bronze for Iqos, and Mango for Juul, even if results varied substantially according to individual smoker. In conclusion, leading MRP have significantly less intense and persistent effects on indoor pollution in comparison to TCC. Yet, when focusing solely on MRP, between-product and between-flavor differences appear, with quantitative estimates suggesting lower polluting effects with Iqos. These results, if confirmed externally, could be used to individualize product and flavor choice to minimize the untoward effects of EVC and HNBC on indoor pollution
Different techniques of surgical left atrial appendage closure and their efficacy. a systematic review
Background: Atrial fibrillation has been identified as an independent risk factor for thromboembolic events. Since 1948 different surgical techniques have described the feasibility and the rationale of left atrial surgical appendage closure. The aim of this systematic review is to evaluate the reported patency rates of different surgical techniques. Methods: This systematic review was conducted according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Two independent investigators searched the PubMed, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, and OVID & REG; (Wolters Kluwer, Alphen aan den Rijn, Netherlands) to identify relevant studies. Consecutively, a PICO (Population, Intervention, Comparison and Outcomes) strategy assessment of literature was performed to search eventual other relevant studies that may have been ignored. Results: A total of 42 studies were included in our analysis. The total number of patients who underwent surgical left atrial appendage closure was 5671, and in 61.2% an imaging follow up was performed, mostly with transesophageal echocardiographic evaluation. Success rate for the different techniques was: Clip deployment 98%; Lariat procedure 88%; Surgical amputation 91%; Endocardial suture 74.3%, Epicardial suture 65%; Left atrial appendage closure (LAAC) ligation 60.9%; Stapler technique with excision of left atrial appendage (LAA) 100%; Stapler without excision 70%. Conclusions: To date, data on surgical left atrial appendage closure are poor and not standardized, even if reported rates are acceptable and comparable to transcatheter procedures. If validated on large-scale non-retrospective and multicentric studies, these promising developments may offer a valuable alternative for patients with atrial fibrillation (AF) and ineligible for oral anticoagulation therapy
Interplay between Nox2 activity and platelet activation in patients with sepsis and septic shock. a prospective study
Background. Although preclinical studies highlighted the potential role of NADPH oxidase (NOX) in sepsis, only few studies evaluated the oxidative stress in patients with sepsis and septic shock. The objective of the study is to appraise the oxidative stress status and platelet function in patients with sepsis and septic shock compared to healthy controls. Methods and Results. Patients with sepsis or septic shock admitted to the hospital Policlinico Umberto I (Sapienza University, Rome) underwent a blood sample collection within 1 hour from admission. Platelet aggregation, serum thromboxane B2 (TxB2), soluble NOX2-derived peptides (sNox2-dp), and hydrogen peroxide breakdown activity (HBA) were measured and compared to those of healthy volunteers. Overall, 33 patients were enrolled; of these, 20 (60.6%) had sepsis and 13 (39.4%) septic shock. Compared to healthy controls (n=10, age 67.8±3.2, male 50%), patients with sepsis and septic shock had higher platelet aggregation (49% (IQR 45-55), 60% (55.75-67.25), and 73% (IQR 69-80), respectively, p<0.001), higher serum TxB2 (77.5 (56.5-86.25), 122.5 (114-131.5), and 210 (195-230) pmol/L, respectively, p<0.001), higher sNox2-dp (10 (7.75-12), 19.5 (17.25-21), and 33 (29.5-39) pg/mL, respectively, p<0.001), and lower HBA (75% (67.25-81.5), 50% (45-54.75), and 27% (21.5-32.5), respectively, p<0.001). Although not statistically significant, a trend in higher levels of serum TxB2 and sNox2-dp in patients who died was observed. Conclusions. Patients with septic shock exhibit higher Nox2 activity and platelet activation than patients with sepsis. These insights joined to better knowledge of these mechanisms could guide the identification of future prognostic biomarkers and new therapeutic strategies in the scenario of septic shock
Long-term Results of a Randomized Controlled Trial Analyzing the Role of Systematic Pre-operative Coronary Angiography before Elective Carotid Endarterectomy in Patients with Asymptomatic Coronary Artery Disease
ObjectivesTo evaluate the potential benefit of systematic preoperative coronary-artery angiography followed by selective coronary-artery revascularization on the incidence of myocardial infarction (MI) in patients undergoing carotid endarterectomy (CEA) without a previous history of coronary artery disease (CAD).MethodsWe randomised 426 patients who were candidates for CEA, with no history of CAD, a normal electrocardiogram (ECG), and a normal cardiac ultrasound. In group A (n = 216) all patients underwent coronary angiography before CEA. In group B (n = 210) CEA was performed without coronary angiography. Patients were not blinded for relevant assessments during follow-up. Primary end-point was the occurrence of MI at 3.5 years. The secondary end-point was the overall survival rate. Median length of follow-up was 6.2 years.ResultsIn group A, coronary angiography revealed significant coronary artery stenosis in 68 patients (31.5%). Among them, 66 underwent percutaneous Intervention (PCI) prior to CEA and 2 received combined CEA and coronary-artery bypass grafting (CABG). Postoperatively, no MI was observed in group A, whereas 6 MI occurred in group B, one of which was fatal (p = .01).During the study period, 3 MI occurred in group A (1.4%) and 33 were observed in group B (15.7%), 6 of which were fatal. The Cox model demonstrated a reduced risk of MI for patients in group A receiving coronary angiography (HR,.078; 95% CI, 0.024-0.256; p < .001). In addition, patients with diabetes and patients <70 years presented with an increased risk of MI. Survival analysis at 6 years by Kaplan-Meier estimates was 95.6 ± 3.2% in Group A and 89.7 ± 3.7% in group B (Log Rank = 6.54, p = .01).ConclusionsIn asymptomatic coronary-artery patients, systematic coronary angiography prior to CEA followed by selective PCI or CABG significantly reduces the incidence of late MI and increases long-term survival. (ClinicalTrials.gov number, NCT02260453)
Diet supplementation, probiotics, and nutraceuticals in SARS-CoV-2 infection. A scoping review
The severe acute respiratory syndrome coronavirus 2 (Sars-CoV-2) global pandemic is a devastating event that is causing thousands of victims every day around the world. One of the main reasons of the great impact of coronavirus disease 2019 (COVID-19) on society is its unexpected spread, which has not allowed an adequate preparation. The scientific community is fighting against time for the production of a vaccine, but it is difficult to place a safe and effective product on the market as fast as the virus is spreading. Similarly, for drugs that can directly interfere with viral pathways, their production times are long, despite the great efforts made. For these reasons, we analyzed the possible role of non-pharmacological substances such as supplements, probiotics, and nutraceuticals in reducing the risk of Sars-CoV-2 infection or mitigating the symptoms of COVID-19. These substances could have numerous advantages in the current circumstances, are generally easily available, and have negligible side effects if administered at the already used and tested dosages. Large scientific evidence supports the benefits that some bacterial and molecular products may exert on the immune response to respiratory viruses. These could also have a regulatory role in systemic inflammation or endothelial damage, which are two crucial aspects of COVID-19. However, there are no specific data available, and rigorous clinical trials should be conducted to confirm the putative benefits of diet supplementation, probiotics, and nutraceuticals in the current pandemic
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