159 research outputs found

    Progettazione di traiettorie su robot industriali per applicazioni di siliconatura

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    L’attività di tesi nasce dalla necessità di una grande multinazionale produttrice di elettrodomestici di valutare una nuova tipologia di silicone per l’incollaggio di componenti di vario tipo per una catena di prodotti riguardanti forni da cucina. Lo scopo del lavoro, prevalentemente di natura pratica, è realizzare gli incollaggi dei componenti col silicone SIKA, in modo da valutare se tale materiale presenti similari qualità di adesione rispetto a quello attualmente utilizzato in produzione, ossia Dow Corning, per permettere alla multinazionale stessa i test distruttivi e verificare se il nuovo silicone può essere utilizzato in linea di produzione senza conseguenze. Per realizzare il lavoro quindi si sono ricreate il più fedelmente possibile le condizioni reali di produzione in linea dei componenti, utilizzando un robot KUKA per la realizzazione dei cordoni di siliconatura nella sede di Constructa, azienda forlivese dove è stato svolto il tirocinio. La prima fase del lavoro consiste in uno step di formazione riguardante l’utilizzo e la programmazione del robot per potere in un secondo momento progettare le traiettorie dell’ugello, che con un apposito sistema di spinta depositerà il silicone. La progettazione ha toccato tutte le fasi di realizzazione di un prodotto: hardware, software e realizzazione dei campioni per i test di prova che verranno effettuati nella sede della multinazionale in Polonia

    Medium-Long-Term Radiographic and Clinical Outcomes after Surgical Treatment of Intra-Articular Tibial Pilon Fractures by Three Different Techniques

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    The goal of this retrospective, observational, case series study was to evaluate the medium-long-term clinical and radiographic results of the three most common surgical osteosynthesis techniques used for the treatment of articular tibial pilon fractures: ORIF, MIPO, and EF. Materials and Methods. A consecutive series of patients with articular pilon fractures who underwent surgery at our institution were enrolled in this study. Fractures were classified according to the M\ufcller AO classification system. Overall outcomes took the following into account: radiographic quality of reduction, evaluated using Ovadia and Beals\u2019 criteria; clinical assessment, evaluated using the AOFAS questionnaire; and general health, evaluated with the SF36-v2 Health Survey. Results. A total of 94 articular pilon fractures (34 type 43-B and 60 43-C) were evaluated with a mean follow-up of 56.34 months (range 33\u2013101). The techniques used were ORIF, MIPO, and EF in 63 (67%), 17 (18.9%), and 14 cases (14.1%), respectively. According to Ovadia and Beals\u2019 criteria, good, fair, and poor results were reported in 61 (64.89%), 26 (27.66%), and 7 (7.45%) cases, respectively. The mean AOFAS score was 82.41 for MIPO, 79.83 for ORIF, and 50.57 for EF, respectively. Thirty-nine patients (41.49%) presented early and/or late complications. Conclusion. Satisfactory outcomes using the three different techniques were reported. In particular, the radiographic outcomes were inversely proportional to the fracture comminutions and statistically different between internal and external osteosynthesis, but comparable between ORIF and MIPO techniques. On the other hand, the clinical outcomes were closely related to the soft tissue conditions and the anatomical reconstruction of the joint

    Invasive versus conservative management in spontaneous coronary artery dissection: A meta-analysis and meta-regression study.

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    Abstract Background There is a paucity of data regarding the best treatment for spontaneous coronary artery dissection (SCAD). Purpose To compare the prognostic impact of conservative versus invasive treatment in patients with SCAD. Methods We systematically searched the literature for studies evaluating the comparative efficacy and safety of invasive revascularization versus medical therapy for the treatment of SCAD from 1990 to 2019. Random-effect meta-analysis was performed comparing clinical outcomes between the two groups. Results 24 observational studies with 1720 patients were included. After 28±14 months, a conservative approach reduced target vessel revascularization rate compared with invasive treatment (OR=0.50; 95% CI 0.28–0.90; P=0.02). No difference was found regarding all-cause mortality (OR=0.81; 95% CI 0.31–2.08; P=0.66), cardiovascular mortality (OR=0.89; 95% CI 0.15–5.40; P=0.89), myocardial infarction (OR=0.95; 95% CI 0.50–1.81; P=0.87), heart failure (OR 0.96; 95% CI 0.41–2.22; P=0.92) and SCAD recurrence (OR=0.94; 95% CI 0.52–1.72; P=0.85). The meta-regression analysis suggested that male gender, diabetes mellitus, smoking habit, prior coronary artery disease, left main coronary artery involvement and lower ejection fraction at admission are related with higher overall mortality, whereas SCAD recurrence was higher among patients with fibromuscular dysplasia. Conclusion A conservative approach provides similar clinical outcomes and lower target vessel revascularization rates compared to an invasive strategy in the setting of SCAD; therefore, when feasible, it should be preferred in this scenario. Forest plots on the study outcomes Funding Acknowledgement Type of funding source: Non

    Percutaneous Coronary Intervention (PCI) Reprograms Circulating Extracellular Vesicles from ACS Patients Impairing Their Cardio-Protective Properties

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    Extracellular vesicles (EVs) are promising therapeutic tools in the treatment of cardiovascular disorders. We have recently shown that EVs from patients with Acute Coronary Syndrome (ACS) undergoing sham pre-conditioning, before percutaneous coronary intervention (PCI) were cardio-protective, while EVs from patients experiencing remote ischemic pre-conditioning (RIPC) failed to induce protection against ischemia/reperfusion Injury (IRI). No data on EVs from ACS patients recovered after PCI are currently available. Therefore, we herein investigated the cardio-protective properties of EVs, collected after PCI from the same patients. EVs recovered from 30 patients randomly assigned (1:1) to RIPC (EV-RIPC) or sham procedures (EV-naive) (NCT02195726) were characterized by TEM, FACS and Western blot analysis and evaluated for their mRNA content. The impact of EVs on hypoxia/reoxygenation damage and IRI, as well as the cardio-protective signaling pathways, were investigated in vitro (HMEC-1 + H9c2 co-culture) and ex vivo (isolated rat heart). Both EV-naive and EV-RIPC failed to drive cardio-protection both in vitro and ex vivo. Consistently, EV treatment failed to activate the canonical cardio-protective pathways. Specifically, PCI reduced the EV-naive Dusp6 mRNA content, found to be crucial for their cardio-protective action, and upregulated some stress- and cell-cycle-related genes in EV-RIPC. We provide the first evidence that in ACS patients, PCI reprograms the EV cargo, impairing EV-naive cardio-protective properties without improving EV-RIPC functional capability

    Matrix metalloproteinase-9 might affect adaptive immunity in non-ST segment elevation acute coronary syndromes by increasing CD31 cleavage on CD4+ T-cells

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    Aims In patients with acute coronary syndrome (ACS), the higher activity of effector T-cells suggests that mechanisms involving adaptive immunity dysregulation might play a role in coronary instability. The shedding of the functional CD31 domain 1-5 leads to uncontrolled lymphocyte activation. In experimental models, matrix metalloproteinase-9 (MMP-9) has been implicated in endothelial CD31 cleavage. Interestingly, higher serum levels of MMP-9 have been observed in ACS. We aim to investigate the mechanisms underlying CD31 dysregulation in ACS. Methods and results To assess CD31 cleavage on CD4+ T-cells, we analysed by flow cytometry CD4+ T-cells of 30 ACS, 25 stable angina (SA) patients, and 28 controls (CTRL) using two different CD31 antibodies that specifically recognize domain 1-5 or the non-functional membrane-proximal domain 6. The ratio between the domains was significantly lower in ACS than in SA and CTRL (P = 0.002 ACS vs. SA; P = 0.002 ACS vs. CTRL). After stimulation with anti-CD3/CD28, the 1-5/6 domain ratio was significantly lower in ACS than in SA (P = 0.005). ELISA of supernatants obtained from T-cell receptor-stimulated CD4+ T-cells showed higher production of MMP-9 in ACS than in SA (P < 0.001). CD31 domain 1-5 expression in activated CD4+ T-cells from ACS patients increased after treatment with a specific MMP-9 inhibitor (P = 0.042). Conclusion Our study suggest that enhanced MMP-9 release plays a key role in determining the cleavage and shedding of the functional CD31 domain 1-5 in CD4+ T-cells of ACS patients. This mechanism might represent an important therapeutic target to modulate T-cell dysregulation in ACS
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