139 research outputs found

    Controlled Contamination of Epoxy Composites with PDMS and Removal by Laser Ablation

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    Surface preparation is critical to the performance of adhesively bonded composites. During manufacturing, minute quantities of mold release compounds are inevitably deposited on faying surfaces and may compromise bond performance. To ensure safety, mechanical fasteners and other crack arrest features must be installed in the bondlines of primary structures, which negates some advantages of adhesively bonded construction. Laser ablation is an automated, repeatable, and scalable process with high potential for the surface preparation of metals and composites in critical applications such as primary airframe structures. In this study, laser ablation is evaluated on composite surfaces for the removal of polydimethylsiloxane (PDMS), a common mold release material. Composite panels were contaminated uniformly with PDMS film thicknesses as low as 6.0 nm as measured by variable angle spectroscopic ellipsometry. Bond performance was assessed by mechanical testing using a 250 F cure, epoxy adhesive and compared with pre-bond surface inspection results. Water contact angle, optically stimulated electron emission, and laser induced breakdown spectroscopy were used to characterize contaminated and laser ablated surfaces. The failure mode obtained from double cantilever beam tests correlated well with surface characterization data. The test results indicated that even low levels of PDMS were not completely removed by laser ablation

    A Case of Type B Aortic Dissection: The Role of Transesophageal Ultrasound Guidance in Thoracic Endovascular Aortic Repair

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    Thoracic endovascular aortic repair (TEVAR) plays a central role in managing acute and chronic aortic pathologies. With the advancement of transcatheter structural heart procedures, echocardiography has become a key in procedural guidance. Despite consensus on its use for cardiac interventions, ultrasound assistance in aortic procedures is not widely standardized. A 71‐year‐old obese man with chronic type B aortic dissection underwent a TEVAR procedure, using a single‐branched aortic stent graft (EndovastecTM CastorTM) and with transesophageal ultrasound guidance. The preprocedural assessment confirmed the presence of aortic dissection of the descending thoracic aorta with a posterior true lumen (TL) and an anterior false lumen (FL), normal aortic valve anatomy and function, normal left ventricular function, absence of intracavity thrombus, and absence of aortic plaques that could prevent the optimal implantation of the stent graft. During the procedure, a transesophageal echocardiogram (TEE) monitored the positioning of the guide wires, the arrival of the catheter of the thoracic endoprosthesis, and then the implantation of this at the level of the aortic arch and the descending thoracic aorta. Postprocedure TEE evaluation underlined full stent‐graft deployment without leaks and successful exclusion of FL with the beginning of thrombosis. Angiography confirms the exclusion of the aneurysm and the absence of endoleaks. This clinical case demonstrates how transesophageal echocardiographic guidance can improve the TEVAR procedure by minimizing fluoroscopy time, contrast medium use, and enabling a better assessment of the dissection anatomy with real‐time monitoring of both the TL and the FL. In conclusion, TEE can serve as an auxiliary intraoperative imaging tool to provide good information before, during, and after the procedure, increasing the success and safety of the TEVAR

    A Case Report of Aortic Intramural Hematoma: From Diagnosis to Endovascular Treatment Guided by Transesophageal Echocardiography

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    Aortic intramural hematoma (IMH) accounts for approximately 10%–25% of acute aortic syndromes (AAS), and multi-slice computed tomography and magnetic resonance imaging are the leading techniques for diagnosis and classification. In this context, endovascular strategies provide a valid alternative to traditional open surgery and transesophageal echocardiography (TEE) could play a role in therapeutic decision-making and in endovascular repair procedure guidance. A 57-year-old female patient with IMH extending from the left subclavian artery to the upper tract of the abdominal aorta, underwent endovascular aortic repair using an unibody single-branched stent grafting in the aortic arch and descending aorta with a side branch inserted in the left common carotid artery. To restore proper flow in the left axillary artery, a carotid-subclavian bypass graft was performed. The procedure was guided by angiography and TEE. Intraoperative TEE revealed aortic IMH with a significant fluid component in the middle tunic of the aorta with a wall thickness of over 13 mm. TEE was useful in monitoring of all steps of the procedure, showing the presence of the guidewires into the true lumen, the advancement of the prosthesis, and the phases of release and anchoring. This case highlights the importance of using multimodality imaging techniques to evaluate AAS and demonstrates the growing potential of TEE in guiding endovascular repairs

    miR-302b enhances breast cancer cell sensitivity to cisplatin by regulating E2F1 and the cellular DNA damage response

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    The identification of the molecular mechanisms involved in the establishment of the resistant phenotype represents a critical need for the development of new strategies to prevent or overcome cancer resistance to anti-neoplastic treatments.Breast cancer is the leading cause of cancer-related deaths in women, and resistance to chemotherapy negatively affects patient outcomes. Here, we investigated the potential role of miR-302b in the modulation of breast cancer cell resistance to cisplatin.miR-302b overexpression enhances sensitivity to cisplatin in breast cancer cell lines, reducing cell viability and proliferation in response to the treatment. We also identified E2F1, a master regulator of the G1/S transition, as a direct target gene of miR-302b. E2F1 transcriptionally activates ATM, the main cellular sensor of DNA damage. Through the negative regulation of E2F1, miR-302b indirectly affects ATM expression, abrogating cell-cycle progression upon cisplatin treatment. Moreover miR-302b, impairs the ability of breast cancer cells to repair damaged DNA, enhancing apoptosis activation following cisplatin treatment.These findings indicate that miR-302b plays a relevant role in breast cancer cell response to cisplatin through the modulation of the E2F1/ATM axis, representing a valid candidate as therapeutic tool to overcome chemotherapy resistance

    The enigma of the ‘smoker's paradox’: Results from a single-center registry of patients with STEMI undergoing primary percutaneous coronary intervention

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    Background: Smoker's paradox usually refers to the observation of a favorable outcome of smoking patients in acute myocardial infarction. Methods: From April 2006 to December 2018 a population of 2456 patients with ST segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI) were prospectively enrolled in the MATRIX registry. Ischemic time, clinical, demographics, angiographic data, and 1-year follow-up were collected. Results: Among 2546 patients admitted with STEMI, 1007 (41 %) were current smokers. Smokers were 10 years younger and had lower crude in-hospital and 1-year mortality (1.5 % vs 6 %, p < 0.0001 and 5 % vs 11 %, p < 0.0001), shorter ischemic time (203 [147–299] vs 220 [154–334] minutes, p = 0.002) and shorter decision time (60 [30–135] vs 70 [36–170] minutes, p = 0.0063). Smoking habit [OR:0.37(95 % CI:0.18–0.75)-p < 0.01], younger age [OR 1.06 (95%CI:1.04–1.09)-p < 0.001] and shorter ischemic time [OR:1.01(95%CI:1.01–1.02)-p < 0.05] were associated to lower in-hospital mortality. Only smoking habit [HR:0.65(95 % CI: 0.44–0.9)–p = 0.03] and younger age [HR:1.08 (95%CI:1.06–1.09)–p < 0.001] were also independently associated to lower all-cause death at 1-year follow-up. After propensity matching, age, cardiogenic shock and TIMI flow <3 were associated with in-hospital mortality, while smoking habit was still associated with reduced mortality. Smoking was also associated with reduced mortality at 1-year follow-up (HR 0.54, 95 % CI [0.37–0.78]; p < 0.001). Conclusions: Smoking patients show better outcome after PCI for STEMI at 1-year follow-up. Although “Smoking paradox” could be explained by younger age of patients, other factors may have a role in the explanation of the phenomenon

    Predictive value of less than moderate residual mitral regurgitation as assessed by transesophageal echocardiography for the short-term outcomes of patients with mitral regurgitation treated with mitral valve repair

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    <p>Abstract</p> <p>Background</p> <p>Traditionally, in patients with mitral regurgitation (MR) a successful mitral valve repair is considered when residual MR by post-pump transesophageal echocardiography (TEE) is less than moderate or absent. Little is known about the prognostic value of less than moderate (mild or mild-to-moderate) residual MR for the early outcome of patients treated with mitral valve repair.</p> <p>Methods</p> <p>Eligible for this study were patients undergoing isolated mitral valve repair. Patients with moderate or severe residual MR after valve repair were excluded. The primary endpoint of the study was the composite of death or need of reintervention.</p> <p>Results</p> <p>A total of 98 patients (54 with no residual MR-Group 1, and 44 with less than moderate residual MR-Group 2) were analyzed. Of these, 72% presented with New York Heart Association (NYHA) 3/4, and 38% were women. The primary endpoint of the study occurred in 3 (5.5%) patients in Group 1 and 6 (13.6%) patients in Group 2 MR (<it>P </it>= 0.31). There was a trend toward a higher incidence of use of inotropic drugs post-interventional (<it>P </it>= 0.12), and a longer hospital stay among patients with less than moderate residual MR (<it>P </it>= 0.18).</p> <p>Conclusion</p> <p>In our study population, patients with less than moderate residual MR had a trend toward a higher risk of early adverse outcomes as compared with patients with no residual MR by post-pump TEE. Studies with a larger patient population and longer follow-up data may be useful to better define the clinical significance of residual mild MR after mitral vale repair.</p

    Influence of involvement of anterior leaflet versus posterior leaflet on residual regurgitation as assessed by transesophageal echocardiography in patients undergoing valve repair for mitral regurgitation due to mitral valve prolapse

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    <p>Abstract</p> <p>Background</p> <p>Repair of anterior leaflet prolapse is technically more challenging and this might influence outcomes as compared to the repair of posterior leaflet prolapse in patients undergoing surgical correction of mitral regurgitation. We investigated the association of anterior leaflet prolapse with minor residual mitral regurgitation (MR) in patients with mitral valve prolapse (MVP) who underwent valve repair.</p> <p>Methods</p> <p>Eligible for this study were consecutive patients with severe MR due to MVP, who underwent mitral valve repair with residual MR by postpump transesophageal echocardiography ≤2+ during a 20-month period at Pasquinucci Hospital, Massa. Patients undergoing other cardiovascular surgical interventions were excluded. Two groups were defined according to the involvement of mitral valve leaflets: group 1, consisting of patients with anterior leaflet prolapse (isolated or not); and group 2, consisting of patients with isolated posterior leaflet prolapse.</p> <p>Results</p> <p>A total of 70 patients (18 in group 1 and 52 in group 2) were analyzed. Patients in group 2 were younger than those in group 1, but the difference was not significant (P = 0.052). There were no significant differences between the 2 study groups with respect to other variables. The proportion of patients with residual MR 1+/2+ was higher in group 1 than in group 2 (61.1% vs. 32.7%, respectively; P = 0.034). In a logistic regression model, anterior leaflet prolapse was an independent predictor of residual MR 1+/2+ (odds ratio, 4.0; 95% confidence interval, 1.14 to 14.04; P = 0.03).</p> <p>Conclusion</p> <p>In our study population, patients with anterior leaflet prolapse had a higher proportion of residual MR 1+/2+ as compared to those with posterior leaflet prolapse after repair of mitral valve.</p

    Application of an updated methodology to estimate the burden of healthcare-associated infections in Italy, 2022

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    Background: Accurate burden estimates are necessary to inform priority setting and rational resource allocation. Weighting prevalence inversely proportional to time-at-risk has been proposed as a solution for length-biased sampling, an important limitation affecting prevalence to incidence conversion for healthcare-associated infections (HAIs). Aim: This study aimed to update Italian burden estimates by calculating HAI incidence, attributable mortality and disability-adjusted life years (DALYs). Further, we describe an adapted methodology for burden estimations. Methods: We used data from the latest European Centre for Disease Prevention and Control (ECDC) point prevalence survey (PPS) of HAIs, conducted in Italy in November 2022, to calculate the burden of five major HAIs at national level. We adapted the Burden of Communicable Diseases in Europe (BCoDE) methodology to include inverse probability weighting and compared results of na & iuml;ve and weighted calculations. Results: The national sample included 18,397 patients. Overall, 564.8 DALYs per 100,000 general population resulted from weighted calculations (95% uncertainty interval (UI): 450.04-694.38), with an annual incidence of 685.42 cases per 100,000 general population (95% UI: 611.09-760.86) and 33.23 deaths per 100,000 general population per year (95% UI: 28.62-38.33). Concerning na & iuml;ve estimates, overall 1,017.81 DALYs per 100,000 general population were calculated (95% UI: 855.16-1,190.59). In both calculations, healthcare-acquired bloodstream infections had the highest burden in terms of DALYs per 100,000 hospitalised and general population. Conclusion: Our study confirmed the substantial burden of HAIs in Italy and renews the need to prioritise resources for infection prevention and control interventions
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