97 research outputs found

    On the Unification of Process Semantics: Logical Semantics

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    We continue with the task of obtaining a unifying view of process semantics by considering in this case the logical characterization of the semantics. We start by considering the classic linear time-branching time spectrum developed by R.J. van Glabbeek. He provided a logical characterization of most of the semantics in his spectrum but, without following a unique pattern. In this paper, we present a uniform logical characterization of all the semantics in the enlarged spectrum. The common structure of the formulas that constitute all the corresponding logics gives us a much clearer picture of the spectrum, clarifying the relations between the different semantics, and allows us to develop generic proofs of some general properties of the semantics.Comment: In Proceedings SOS 2011, arXiv:1108.279

    Comparison of single- and multistage strategies during fenestrated-branched endovascular aortic repair of thoracoabdominal aortic aneurysms

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    Objective: The aim of this study was to compare outcomes of single or multistage approach during fenestrated-branched endovascular aortic repair (FB-EVAR) of extensive thoracoabdominal aortic aneurysms (TAAAs). Methods: We reviewed the clinical data of consecutive patients treated by FB-EVAR for extent I to III TAAAs in 24 centers (2006-2021). All patients received a single brand manufactured patient-specific or off-the-shelf fenestrated-branched stent grafts. Staging strategies included proximal thoracic aortic repair, minimally invasive segmental artery coil embolization, temporary aneurysm sac perfusion and combinations of these techniques. Endpoints were analyzed for elective repair in patients who had a single- or multistage approach before and after propensity score adjustment for baseline differences, including the composite 30-day/in-hospital mortality and/or permanent paraplegia, major adverse event, patient survival, and freedom from aortic-related mortality. Results: A total of 1947 patients (65% male; mean age, 71 ± 8 years) underwent FB-EVAR of 155 extent I (10%), 729 extent II (46%), and 713 extent III TAAAs (44%). A single-stage approach was used in 939 patients (48%) and a multistage approach in 1008 patients (52%). A multistage approach was more frequently used in patients undergoing elective compared with non-elective repair (55% vs 35%; P < .001). Staging strategies were proximal thoracic aortic repair in 743 patients (74%), temporary aneurysm sac perfusion in 128 (13%), minimally invasive segmental artery coil embolization in 10 (1%), and combinations in 127 (12%). Among patients undergoing elective repair (n = 1597), the composite endpoint of 30-day/in-hospital mortality and/or permanent paraplegia rate occurred in 14% of single-stage and 6% of multistage approach patients (P < .001). After adjustment with a propensity score, multistage approach was associated with lower rates of 30-day/in-hospital mortality and/or permanent paraplegia (odds ratio, 0.466; 95% confidence interval, 0.271-0.801; P = .006) and higher patient survival at 1 year (86.9±1.3% vs 79.6±1.7%) and 3 years (72.7±2.1% vs 64.2±2.3%; adjusted hazard ratio, 0.714; 95% confidence interval, 0.528-0.966; P = .029), compared with a single stage approach. Conclusions: Staging elective FB-EVAR of extent I to III TAAAs was associated with decreased risk of mortality and/or permanent paraplegia at 30 days or within hospital stay, and with higher patient survival at 1 and 3 years

    Ecology of Juvenile Salmon in Shallow Tidal Freshwater Habitats of the Lower Columbia River, 2007?2010

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    The TFM study was designed to investigate the ecology and early life history of juvenile salmonids within shallow (<5 m) tidal freshwater habitats of the LCRE. We started collecting field data in June 2007. Since then, monthly sampling has occurred in the vicinity of the Sandy River delta (rkm 192–208) and at other sites and times in lower river reaches of tidal freshwater (rkm 110 to 141). This report provides a comprehensive synthesis of data covering the field period from June 2007 through April 2010

    Case series of aortic arch disease treated with branched stent-grafts

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    Abstract Background Surgical repair of aortic arch pathology is complex and associated with significant morbidity and mortality. Alternative approaches have been developed to reduce these risks, including the use of thoracic stent-grafts with fenestrations or in combination with bypass procedures to maintain supra-aortic trunk blood flow. Branched stent-grafts are a novel approach to treat aortic arch pathology. Methods Consecutive patients with aortic arch disease presenting to a single university hospital vascular centre were considered for branched stent-graft repair (October 2010 to January 2017). Patients were assessed in a multidisciplinary setting including a cardiologist, cardiac surgeon and vascular surgeon. All patients were considered prohibitively high risk for standard open surgical repair. The study used reporting standards for endovascular aortic repair and PROCESS (Preferred Reporting of Case Series in Surgery) guidelines. Results Some 30 patients (25 men) underwent attempted branch stent-graft repair. Mean age was 68 (range 37–84) years. Eighteen patients had chronic aortic dissection, 11 patients had an aneurysm and one had a penetrating ulcer. Fourteen patients had disease in aortic arch zone 0, six in zone 1 and ten in zone 2. Twenty-five patients had undergone previous aortic surgery and 24 required surgical revascularization of the left subclavian artery. Technical success was achieved in 27 of 30 patients. Four patients had an endoleak (type Ia, 1; type II, 3). The in-hospital mortality rate was three of 30. Mean length of follow-up was 12·0 (range 1·0–67·8) months, during which time 12 patients required an aortic-related reintervention. Conclusion Repair of aortic arch pathology using branched stent-grafting appears feasible. Before widespread adoption of this technology, further studies are required to standardize the technique and identify which patients are most likely to benefit. </jats:sec

    SiC MOSFET soot sensor in a co-fired LTCC package

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    Abstract A novel method for soot detection based on SiC MOSFET devices with a dual suspended/ floating gate configuration in a co-fired LTCC package has been investigated. Response to different concentrations of soot was measured through the application of an electric field between the two gate electrodes to attract charged soot onto the sensor surface. Results are promising with application areas from automotive and transportation to air pollution control

    Aortic treatment in connective tissue disease

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    Connective tissue disease (CTD) represents a group of genetic conditions characterized by disruptive matrix remodeling. When this process involves aortic and vascular wall, patients with CTD have a high risk of developing arterial aneurysms, dissections and ruptures. Open surgical repair is still the gold standard therapy for patients with CTD with reasonable morbidity and mortality risk. The surgical treatment of CTD often requires multiple operations. In the endovascular era, fenestrated and branched stent grafts may play a role in reducing the complications of multiple open operations. Although the long-term results of endovascular treatment in the setting of CTD are unknown, it is generally accepted that endovascular treatment is restricted to selected patients with high surgical risk. In an emergency setting, endovascular intervention can serve as a lifesaving bridge to elective open aortic repair. Aortic centers performing a large volume of complex open and endovascular aortic repairs have started to combine these two techniques in a staged fashion. The goal is to reduce the morbidity and mortality associated with extensive aortic repairs in CTD patients. For this reason, recommend endovascular therapy when a \u201cgraft-to-graft\u201d approach is possible. In this scenario, the surgeon who performs the open repair must take into consideration future interventions. Surgical repair in any aortic segment should allow creation of proximal and distal landing zones over 4 cm to secure the sealing of a future stent graft. Connective tissue disease should be treated with a multidisciplinary approach, in high volume centers. Endovascular treatment represents a potential option in patients at high risk for open repair. Staged hybrid procedures have emerged as a way to reduce spinal cord ischemia and avoid multiple open surgeries. The aim of this article is to discuss the management of aortic diseases in CTD, focusing on to the role of standard open surgery and emerging endovascular treatment, and to give an overview of the few series published regarding this topic with a small number of patients
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