Serviço de vídeo a pedido através da Internet

O presente téxto tem o objectivo de introduzir os conceitos relacionados com a transmissão de vídeo através da Internet. Através da realização, implementação e estudo de uma plataforma de suporte ao serviço de vídeo a pedido, analisam-se os principais problemas inerentes à concepção de um serviço deste tipo. Apresenta-se uma solução para um clube de vídeo on-line, mostrando uma implementação possível para o serviço de vídeo em tempo real. Por fim fazem-se as conclusões e enumeram-se algumas direcções para melhorar a qualidade do serviço

ACUTE CAROTID STENT THROMBOSIS – A RARE CLINICAL ENTITY?

Introduction: Acute carotid stent thrombosis (ACST), defined according to the Academic Research Consortium as occurring in the first 24 hours after the procedure, is described as an exceedingly rare complication of CAS but it can lead to catastrophic neurologic consequences. The European Society for Vascular Surgery updated guidelines state thrombolysis and intravenous abciximab may be effective, but provide no specific recommendations. Given the lack of data concerning the optimal management, the purpose of this review was to evaluate the current literature and report on ACST aetiology and management strategies. Methods: Literature review was performed in the MEDLINE database. Results: No data on ACST is evident in large randomized controlled trials. ACST incidence rate ranges from 0.5-0.8%, reaching as high as 33% in acute-setting.   Considering aetiology, it can be subdivided into 2 main groups: systemic causes and technical complications. In the first antiplatelet non-compliance/resistance were the most reported while in the latter carotid artery dissection and plaque protrusion were the most common causes. Also, dual layer stents were associated with greater risk for ACST There are three main approaches for ACST: pharmacologic, endovascular and surgical. Pharmacologic management included anticoagulation, thrombolysis and facilitated thrombolysis. A role for thrombolysis and facilitated thrombolysis is still to be determined. Endovascular treatment was the most common approach to intraprocedural ACST: mechanical thrombectomy with or without concomitant facilitated thrombolysis. Surgical options included carotid endarterectomy with stent explantation which was a bail-out after failed endovascular treatment with excellent recanalization rates. In asymptomatic ACST conservative management with anticoagulation was unanimous. Discussion: As a conclusion, ACST is probably an underestimated clinical entity associated with multiple risk factors. Decision on the best approach depends if ACST occurs intraprocedural or afterwards, on the development of neurologic status deterioration and on centre´s experience. Additional studies must be undertaken to better define optimal management

Physiological parameters for Prognosis in Abdominal Sepsis (PIPAS) Study : a WSES observational study

BackgroundTiming and adequacy of peritoneal source control are the most important pillars in the management of patients with acute peritonitis. Therefore, early prognostic evaluation of acute peritonitis is paramount to assess the severity and establish a prompt and appropriate treatment. The objectives of this study were to identify clinical and laboratory predictors for in-hospital mortality in patients with acute peritonitis and to develop a warning score system, based on easily recognizable and assessable variables, globally accepted.MethodsThis worldwide multicentre observational study included 153 surgical departments across 56 countries over a 4-month study period between February 1, 2018, and May 31, 2018.ResultsA total of 3137 patients were included, with 1815 (57.9%) men and 1322 (42.1%) women, with a median age of 47years (interquartile range [IQR] 28-66). The overall in-hospital mortality rate was 8.9%, with a median length of stay of 6days (IQR 4-10). Using multivariable logistic regression, independent variables associated with in-hospital mortality were identified: age > 80years, malignancy, severe cardiovascular disease, severe chronic kidney disease, respiratory rate >= 22 breaths/min, systolic blood pressure 4mmol/l. These variables were used to create the PIPAS Severity Score, a bedside early warning score for patients with acute peritonitis. The overall mortality was 2.9% for patients who had scores of 0-1, 22.7% for those who had scores of 2-3, 46.8% for those who had scores of 4-5, and 86.7% for those who have scores of 7-8.ConclusionsThe simple PIPAS Severity Score can be used on a global level and can help clinicians to identify patients at high risk for treatment failure and mortality.Peer reviewe

Multicriteria Optimization of Gasification Operational Parameters Using a Pareto Genetic Algorithm

Gasification is a well-known technology that allows for a combustible gas to be obtained from a carbonaceous fuel by a partial oxidation process (POX). The resulting gas (synthesis gas or syngas) can be used either as a fuel or as a feedstock for chemical production. Recently, gasification has also received a great deal of attention concerning power production possibilities through IGCC process (Integrated Gasification Combined Cycle), which is currently the most environmentally friendly and efficient method for the production of electricity. Gasification allows for low grade fuels, or dirty fuels, to be used in an environmental acceptable way. Amongst these fuels are wastes from the petrochemical and other industries, which vary in composition from shipment to shipment, and from lot to lot. If operating conditions are kept constant this could result in lose of efficiency. This paper presents an application of Genetic Algorithms to optimize the operating parameters of a gasifier processing a given fuel, so that the system achieves maximum efficiency for each particular fuel composition. A Pareto multiobjective optimization method, combined with a Genetic Algorithm, is applied to the simultaneous maximization of two different objective functions: Cold Gas Efficiency and Hydrogen Contents of the syngas. Results show that the optimization method developed is fast and simple enough to be used for on-line adjustment of the gasification operating parameters for each fuel composition and aim of gasification, thus improving overall performance of the industrial process

Stoma-free survival after anastomotic leak following rectal cancer resection: worldwide cohort of 2470 patients

Background: The optimal treatment of anastomotic leak after rectal cancer resection is unclear. This worldwide cohort study aimed to provide an overview of four treatment strategies applied. Methods: Patients from 216 centres and 45 countries with anastomotic leak after rectal cancer resection between 2014 and 2018 were included. Treatment was categorized as salvage surgery, faecal diversion with passive or active (vacuum) drainage, and no primary/secondary faecal diversion. The primary outcome was 1-year stoma-free survival. In addition, passive and active drainage were compared using propensity score matching (2: 1). Results: Of 2470 evaluable patients, 388 (16.0 per cent) underwent salvage surgery, 1524 (62.0 per cent) passive drainage, 278 (11.0 per cent) active drainage, and 280 (11.0 per cent) had no faecal diversion. One-year stoma-free survival rates were 13.7, 48.3, 48.2, and 65.4 per cent respectively. Propensity score matching resulted in 556 patients with passive and 278 with active drainage. There was no statistically significant difference between these groups in 1-year stoma-free survival (OR 0.95, 95 per cent c.i. 0.66 to 1.33), with a risk difference of -1.1 (95 per cent c.i. -9.0 to 7.0) per cent. After active drainage, more patients required secondary salvage surgery (OR 2.32, 1.49 to 3.59), prolonged hospital admission (an additional 6 (95 per cent c.i. 2 to 10) days), and ICU admission (OR 1.41, 1.02 to 1.94). Mean duration of leak healing did not differ significantly (an additional 12 (-28 to 52) days). Conclusion: Primary salvage surgery or omission of faecal diversion likely correspond to the most severe and least severe leaks respectively. In patients with diverted leaks, stoma-free survival did not differ statistically between passive and active drainage, although the increased risk of secondary salvage surgery and ICU admission suggests residual confounding