593 research outputs found
Effect of corrosion-induced hydrogen embrittlement and its degradation impact on tensile properties and fracture toughness of (Al-Cu-Mg) 2024 alloy
No full textAbstractIn the present work, the effect of artificial ageing of AA2024-T3 on the tensile mechanical properties and fracture toughness degradation due to corrosion exposure will be investigated. Tensile and fracture toughness specimens were artificially aged to tempers that correspond to Under-Ageing (UA), Peak-Ageing (PA) and Over-Ageing (OA) conditions and then were subsequently exposed to exfoliation corrosion environment. The corrosion exposure time was selected to be the least possible according to the experimental work of Alexopoulos et al. (2016) so as to avoid the formation of large surface pits, trying to simulate the hydrogen embrittlement degradation only. The mechanical test results show that minimum corrosion-induced decrease in elongation at fracture was achieved for the peak-ageing condition, while maximum was noticed at the under-ageing and over-ageing conditions. Yield stress decrease due to corrosion is less sensitive to tempering; fracture toughness decrease was sensitive to ageing heat treatment thus proving that the S΄ particles play a significant role on the corrosion-induced degradation
The Liturgical Book of the Oktoechos. Function, Forms, and Manuscript Tradition
No full textThis chapter offers a detailed investigation into the liturgical book known as the Oktoechos within the Byzantine tradition, focusing on its function, structure, and manuscript history. The Author clarifies the multiple meanings of the term "oktoechos" in Byzantine sources, distinguishing between the musical eight-mode system, the weekly liturgical cycle, and the book itself. The study explores the evolution of the Oktoechos from its early roots in the Jerusalem liturgical tradition, particularly through Georgian and Greek sources such as the Old and New Tropologion. The work highlights the interplay between the Oktoechos and other liturgical books like the Menaion, Triodion, and Pentekostarion, and traces the contribution of major hymnographers including John of Damascus and Andrew of Crete. Special attention is given to terminological ambiguities, manuscript variants, and regional adaptations. Overall, the chapter presents a nuanced reconstruction of the development and standardization of this central Byzantine liturgical book
Angiographic estimation of atherosclerotic disease burden in a coronary artery fed by collaterals: a potential pitfall in decision for revascularization
No full textGrigorios Tsigkas, Panagiota Mylona, Periklis Davlouros, Dimitrios AlexopoulosCardiology Department, University Hospital of Patras, Patras, GreeceAbstract: Despite the remarkable advances in revascularization strategies made during the last decade, a significant proportion of patients are excluded from either percutaneous coronary intervention or coronary artery bypass grafting because of unsuitable coronary anatomy. Diffuse severe coronary artery disease, small vessel caliber, chronic total occlusions, or extremely calcified vessels are frequent reasons for deferring revascularization with either percutaneous coronary intervention or coronary artery bypass grafting. We present a case concerning a middle-aged asymptomatic patient who was treated successfully with percutaneous coronary intervention due to a chronic total occlusion lesion of the left anterior descending artery. Coronary angiography is an inadequate method for the estimation of the burden of atherosclerotic disease in an artery fed by collaterals. Assessment of any residual antegrade flow, and ipsilateral and contralateral collateral filling of the segments distal to the occlusion with invasive or noninvasive techniques, could affect the appropriate decision-making by physicians.Keywords: collaterals, percutaneous coronary intervention, coronary artery bypass grafting, ischemia, revascularization, chronic total occlusion 
Early P2Y12 Inhibitors Escalation in Primary PCI Patients: Insights from the RENOVAMI Registry
No full textBackground Early escalation from clopidogrel to new generation P2Y12 inhibitors is common practice in patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). Real-world data about this strategy, however, are limited. Methods From 2012 to 2015, 1,057 consecutive STEMI patients treated with pPCI in an Italian hub-and-spoke network were prospectively included in an observational registry (RENOVAMI, ClinicalTrials.gov Identifier: NCT01760382). We compared the prevalence, predictive factors and in-hospital outcomes of patients escalated to a new generation P2Y12 inhibitor within the first 24 hours from pPCI with those continuing on admission antiplatelet therapy. Results In the first 24 hours after pPCI, 165 patients (15.6%) were escalated from clopidogrel to a new generation P2Y12 inhibitor, while de-escalation to clopidogrel was occasional (19 patients, 1.8%) and switch between new generation P2Y12 inhibitors was rare (8 patients, 0.8%, all from ticagrelor to prasugrel). Drug eluting stent use (adjusted odds ratio [OR], 2.19, 95% confidence interval [CI], 1.55–3.08, p = 0.0002) and impaired renal function (adjusted OR, 0.19, 95% CI, 0.05–0.77, p = 0.02) were the only independent predictive factors for the decision to escalate. After adjustment for potential confounders, escalation did not predict in-hospital outcomes, whereas the overall use of new generation P2Y12 inhibitors was correlated with a better in-hospital survival (adjusted hazard ratio, 0.47, 95% CI, 0.25–0.91, p = 0.03). Moreover, escalation did not influence bleeding rates. Conclusions In this prospective registry of STEMI patients treated with pPCI and contemporary antiplatelet therapy, early escalation to a new generation P2Y12 inhibitor appeared safe and did not significantly affect in-hospital bleeding rates
Socioeconomic status and anxiety as predictors of antidepressant treatment response and suicidal ideation in older adults.
No full textBACKGROUND: Separate reports from the maintenance treatment for late-life depression (MTLD) trials have shown that low socioeconomic status (SES) and anxiety symptoms at the time of treatment initiation predict lower levels of response to antidepressant treatment and higher levels of suicidal ideation in older adults. AIM: To determine whether SES and anxiety independently contribute to worse treatment outcomes, as indicated by persistence of depressive symptoms during treatment and the persistence of suicidal ideation. Consistent with prior evidence that sociodemographic factors and clinical history are both prognostic of depression treatment efficacy, we hypothesized that SES and pre-existing anxiety symptoms will both predict lower levels of response to treatment and higher levels of suicidal ideation. METHOD: Secondary analyses of data from the MTLD trials. RESULTS: Regression analyses which controlled for comorbid anxiety indicated that residents of middle- and high-income census tracts were more likely to respond to treatment (HR, 1.63; 95%CI, 1.08-2.46) and less likely to report suicidal ideation during treatment (OR, 0.51; 95%CI, 0.28-0.90) than residents of low income census tracts. The same regression models indicated that pre-existing anxiety symptoms were independently related to lower treatment response (HR, 0.73; 95%CI, 0.60-0.89) and higher risk of suicidal ideation (OR, 1.45; 95%CI, 0.98-2.14). CONCLUSION: These findings demonstrate the importance of treating anxiety symptoms during the course of treatment for late-life depression and, at the same time, addressing barriers to treatment response related to low SES
<i>CYP2C19*2</i>allele: guiding medication choice after percutaneous coronary intervention
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P2Y12 Receptor Inhibitors in Acute Coronary Syndromes: From the Research Laboratory to the Clinic and Vice Versa
No full textDAPT After Stenting in Stable and Acute Coronary Syndromes- Does the Drug Combination Really Matter?
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