633 research outputs found

    On the motion of a heavy rigid body in an ideal fluid with circulation

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    Chaplygin's equations describing the planar motion of a rigid body in an unbounded volume of an ideal fluid involved in a circular flow around the body are considered. Hamiltonian structures, new integrable cases, and partial solutions are revealed, and their stability is examined. The problems of non-integrability of the equations of motion because of a chaotic behavior of the system are discussed.Comment: 25 pages, 4 figure

    Let-7g and miR-21 expression in non-small cell lung cancer: correlation with clinicopathological and molecular features

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    MicroRNAs (miRNAs) play a key role in cancer pathogenesis and are involved in several human cancers, including non-small cell lung cancer (NSCLC). This study evaluated Let-7g and miR-21 expression by quantitative real-time PCR in 80 NSCLC patients and correlated the results with their main clinicopathological and molecular features. MiR-21 expression was significantly higher in NSCLC tissues compared to non-cancer lung tissues (p<0.0001), while no significant changes in Let-7g expression were observed between the tumor and normal lung tissues. Target prediction analysis led to the identification of 26 miR-21 and 24 Let-7g putative target genes that play important roles in cancer pathogenesis and progression. No significant association was observed between the analysed miRNAs and the main clinicopathological or molecular characteristics of the NSCLC patients, although both miRNAs were downregulated in squamous cell carcinomas compared to adenocarcinomas. Noteworthy, we observed a significant association between low Let-7g expression and metastatic lymph nodes at diagnosis (p=0.046), as well as between high miR-21 expression and K-Ras mutations (p=0.0003). Survival analysis did not show any significant correlation between prognosis and the analysed miRNAs, although the patients with a high Let-7g and miR-21 expression showed a significantly lower short-term progression-free survival (p=0.01 and p=0.0003, respectively) and overall survival (p=0.023 and p=0.0045, respectively). In conclusion, we showed that Let-7g and miR-21 expression was deregulated in NSCLC and we demonstrated a strong relationship between miR-21 overexpression and K-Ras mutations. Our data indicate that Let-7g and miR-21 profiling combined with the determination of K-Ras mutational status may be considered a useful biomarker for a more effective molecular characterization and clinical management of NSCLC patients

    2022 Joint ESC/EACTS review of the 2018 guideline recommendations on the revascularization of left main coronary artery disease in patients at low surgical risk and anatomy suitable for PCI or CABG

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    Task Force structure and summary of clinical evidence of 2022 ESC/EACTS review of the 2018 guideline recommendations on the revascularization of left main coronary artery disease. CABG, coronary artery bypass grafting; PCI, percutaneous coronary intervention; LM, left main; SYNTAX, Synergy Between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery. a'Event' refers to the composite of death, myocardial infarction (according to Universal Definition of Myocardial Infarction if available, otherwise protocol defined) or stroke. In October 2021, the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS) jointly agreed to establish a Task Force (TF) to review recommendations of the 2018 ESC/EACTS Guidelines on myocardial revascularization as they apply to patients with left main (LM) disease with low-to-intermediate SYNTAX score (0-32). This followed the withdrawal of support by the EACTS in 2019 for the recommendations about the management of LM disease of the previous guideline. The TF was asked to review all new relevant data since the 2018 guidelines including updated aggregated data from the four randomized trials comparing percutaneous coronary intervention (PCI) with drug-eluting stents vs. coronary artery bypass grafting (CABG) in patients with LM disease. This document represents a summary of the work of the TF; suggested updated recommendations for the choice of revascularization modality in patients undergoing myocardial revascularization for LM disease are included. In stable patients with an indication for revascularization for LM disease, with coronary anatomy suitable for both procedures and a low predicted surgical mortality, the TF concludes that both treatment options are clinically reasonable based on patient preference, available expertise, and local operator volumes. The suggested recommendations for revascularization with CABG are Class I, Level of Evidence A. The recommendations for PCI are Class IIa, Level of Evidence A. The TF recognized several important gaps in knowledge related to revascularization in patients with LM disease and recognizes that aggregated data from the four randomized trials were still only large enough to exclude large differences in mortality.</p

    are drug eluting stents superior to bare metal stents in patients with unprotected non bifurcational left main disease insights from a multicentre registry

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    Aims To compare long-term clinical outcome following drug-eluting stents (DES) or bare-metal stents (BMS) implantation on lesions located at the ostium or the shaft of the left main in a large real-world population. The advent of DES decreased the risk of unprotected left main coronary artery (ULMCA) restenosis when compared with BMS, but it is unclear if this advantage continues when non-bifurcational lesions are considered. Methods and results The GISE-SICI registry is a retrospective, observational multicentre registry promoted by the Italian Society of Invasive Cardiology in which 19 high-volume participating centres enrolled 1453 consecutive patients who underwent percutaneous coronary intervention on ULMCA between January 2002 and December 2006. From the registry, a total of 479 consecutive patients with ostial and shaft lesions who underwent DES ( n = 334) or BMS ( n = 145) implantation were analysed with extensive multivariable and propensity score adjustments. At 3-year follow-up, risk-adjusted survival rates were higher in patients treated with DES than in those treated with BMS. The adjusted hazard ratio (HR) for the risk of mortality after DES implantation relative to BMS implantation was 0.37 (95% CI: 0.15–0.96, P = 0.04). The adjusted HR for the risk of cardiac mortality was 0.31 (95% CI: 0.09–1.04, P = 0.06). The adjusted 3-year rates of target lesion revascularization (TLR) were not significantly lower in the DES group than in the BMS group ( P = 0.60). Conclusion In a large population of patients with lesions located at the ostium or the shaft of the left main in a real-world setting, DES were associated with favourable clinical outcomes when compared with BMS, although there was no evidence of a significant reduction in TLR with DES vs. BMS

    Potentiation of thrombus instability: a contributory mechanism to the effectiveness of antithrombotic medications

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    © The Author(s) 2018The stability of an arterial thrombus, determined by its structure and ability to resist endogenous fibrinolysis, is a major determinant of the extent of infarction that results from coronary or cerebrovascular thrombosis. There is ample evidence from both laboratory and clinical studies to suggest that in addition to inhibiting platelet aggregation, antithrombotic medications have shear-dependent effects, potentiating thrombus fragility and/or enhancing endogenous fibrinolysis. Such shear-dependent effects, potentiating the fragility of the growing thrombus and/or enhancing endogenous thrombolytic activity, likely contribute to the clinical effectiveness of such medications. It is not clear how much these effects relate to the measured inhibition of platelet aggregation in response to specific agonists. These effects are observable only with techniques that subject the growing thrombus to arterial flow and shear conditions. The effects of antithrombotic medications on thrombus stability and ways of assessing this are reviewed herein, and it is proposed that thrombus stability could become a new target for pharmacological intervention.Peer reviewedFinal Published versio

    Early and long-term outlook of percutaneous coronary intervention for bifurcation lesions in young patients

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    Coronary artery disease is most common in older patients, but may occur in younger subjects. The outlook of young patients after percutaneous coronary intervention (PCI) of challenging lesion subsets such as coronary bifurcations, is not established. We thus aimed to appraise the early and long-term results of PCI for bifurcations in young patients

    Revisiting Sex Equality With Transcatheter Aortic Valve Replacement Outcomes A Collaborative, Patient-Level Meta-Analysis of 11,310 Patients

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    AbstractBackgroundThere has been conflicting clinical evidence as to the influence of female sex on outcomes after transcatheter aortic valve replacement.ObjectivesThe aim of this study was to evaluate the impact of sex on early and late mortality and safety end points after transcatheter aortic valve replacement using a collaborative meta-analysis of patient-level data.MethodsFrom the MEDLINE, Embase, and the Cochrane Library databases, data were obtained from 5 studies, and a database containing individual patient-level time-to-event data was generated from the registry of each selected study. The primary outcome of interest was all-cause mortality. The safety end point was the combined 30-day safety end points of major vascular complications, bleeding events, and stroke, as defined by the Valve Academic Research Consortium when available.ResultsFive studies and their ongoing registry data, comprising 11,310 patients, were included. Women constituted 48.6% of the cohort and had fewer comorbidities than men. Women had a higher rate of major vascular complications (6.3% vs. 3.4%; p < 0.001), major bleeding events (10.5% vs. 8.5%; p = 0.003), and stroke (4.4% vs. 3.6%; p = 0.029) but a lower rate of significant aortic incompetence (grade ≄2; 19.4% vs. 24.5%; p < 0.001). There were no differences in procedural and 30-day mortality between women and men (2.6 % vs. 2.2% [p = 0.24] and 6.5% vs. 6.5% [p = 0.93], respectively), but female sex was independently associated with improved survival at median follow-up of 387 days (interquartile range: 192 to 730 days) from the index procedure (adjusted hazard ratio: 0.79; 95% confidence interval: 0.73 to 0.86; p = 0.001).ConclusionsAlthough women experience more bleeding events, as well as vascular and stroke complications, female sex is an independent predictor of late survival after transcatheter aortic valve replacement. This should be taken into account during patient selection for this procedure
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