12 research outputs found

    Oxidation catalysts prepared from biosorbents supported on zeolites

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    The catalytic oxidation of 1,2-dichlorobenzene was investigated over NaYand NaX zeolites, loaded with chromiumthrough the action of a robust biosorption system consisting of a bacterial biofilm supported on the zeolites. The results of biosorption showed that the maximum metal removal efficiencywas 20%, in both systems based on NaYorNaX, starting fromsolutions with chromium(VI) concentrations ranging from 50 to 250 mgCr/L. The bacterial biofilm, Arthrobacter viscosus, supported on the zeolite reduces Cr(VI) to Cr(III). The Cr(III) is retained in the zeolite by ion exchange. The new catalysts were characterized by spectroscopic methods (FTIR ), chemical analyses (ICP-AES), surface analysis (XRD) and thermal analysis (TGA). The various techniques of characterization show that this biosorption process does not modify the morphology and structure of the FAUzeolites. These catalysts,Cr/FAU, prepared through this newprocedure present good activity and selectivity for dichlorobenzene oxidation in wet air at 350 ºC. The Cr50-Y was selected as the most active, selective and stable catalyst for oxidation of 1,2-dichlorobenzene in wet air.Departamento de Ciências da Terra of Universidade do Minho; Fundação para a Ciência e a Tecnologia (FCT) ; Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME); Région Poitou-Charentes

    Catalytic behavior of biosorbents supported in zeolites

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    The catalytic oxidation of 1,2-dichlorobenzene at 350 oC was investigated over a robust biosorption system consisting of a bacterial biofilm supported on NaY or NaX zeolites. The batch method has been employed using chromium concentrations in solution ranging from 50 to 250 mgCr/L. The results showed that the maximum removal efficiency was 20% for Cr in both systems based in NaY or NaX. The bacterial biofilm, Arthrobacter viscosus, supported on the zeolite reduces Cr(VI) to Cr(III). The Cr(III) is retained in the zeolite by ion exchange. The new biosorvents catalysts were characterized by spectroscopic methods (FTIR and ICP-AES), surface analysis (DRX) and thermal analysis (TGA). The various techniques of characterization used show that this biosorption process does not modify the morphology and structure of the FAUzeolites. These catalysts, Cr/FAU, prepared through this new procedure present good activity and selectivity for dichlorobenzene oxidation in wet air. The Cr50-Y was selected as the most active, selective and stable catalyst for oxidation of 1,2 dichlorobenzene in wet air.Fundação para a Ciência e a Tecnologia (FCT)Departamento de Ciências da Terra of Universidade do MinhoAgence de l’Environnement et de la Maîtrise de l’Energie (ADEME) and the Région Poitou-Charente

    The management of acute venous thromboembolism in clinical practice. Results from the European PREFER in VTE Registry

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    Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in Europe. Data from real-world registries are necessary, as clinical trials do not represent the full spectrum of VTE patients seen in clinical practice. We aimed to document the epidemiology, management and outcomes of VTE using data from a large, observational database. PREFER in VTE was an international, non-interventional disease registry conducted between January 2013 and July 2015 in primary and secondary care across seven European countries. Consecutive patients with acute VTE were documented and followed up over 12 months. PREFER in VTE included 3,455 patients with a mean age of 60.8 ± 17.0 years. Overall, 53.0 % were male. The majority of patients were assessed in the hospital setting as inpatients or outpatients (78.5 %). The diagnosis was deep-vein thrombosis (DVT) in 59.5 % and pulmonary embolism (PE) in 40.5 %. The most common comorbidities were the various types of cardiovascular disease (excluding hypertension; 45.5 %), hypertension (42.3 %) and dyslipidaemia (21.1 %). Following the index VTE, a large proportion of patients received initial therapy with heparin (73.2 %), almost half received a vitamin K antagonist (48.7 %) and nearly a quarter received a DOAC (24.5 %). Almost a quarter of all presentations were for recurrent VTE, with >80 % of previous episodes having occurred more than 12 months prior to baseline. In conclusion, PREFER in VTE has provided contemporary insights into VTE patients and their real-world management, including their baseline characteristics, risk factors, disease history, symptoms and signs, initial therapy and outcomes

    Dynamics of Ag+ ions in RbAg4I5 probed indirectly via 87Rb solid-state NMR

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    Solid-state 87Rb NMR has been used to determine the ionic hopping rate of Ag+ ions in a powdered sample of \u3b1-RbAg 4I5 as a function of temperature from 20 to 250 C. In this phase, Rb is a stationary framework atom, which does not take part in ionic conduction in this material. At the same time 87Rb has a large quadrupole moment, making 87Rb NMR capable of detecting mobile species in close proximity. Simulation of the static 87Rb NMR powder pattern under the influence of Ag+ motion was performed using the EXPRESS software. Lineshape simulations were used to extract an ionic hopping rate for each temperature, and changes in the line shape were correlated to changes in ion mobility, which increases with temperature. Ag+ hopping rates were found to be in the range of 7.0 \ub1 0.5 kHz to 30 \ub1 2 kHz within the temperature window of 20 to 100 C, resulting in an activation energy of 17 \ub1 3 kJ/mol (0.18 \ub1 0.03 eV), for silver ion hopping. This result is in agreement with previous studies, suggesting that this indirect method of detecting ion mobility can be extended to other ion conducting materials. \ua9 2013 American Chemical Society.Peer reviewed: YesNRC publication: Ye

    The management of acute venous thromboembolism in clinical practice - study rationale and protocol of the European PREFER in VTE Registry

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    Background: Venous thromboembolism (VTE) is a major health problem, with over one million events every year in Europe. However, there is a paucity of data on the current management in real life, including factors influencing treatment pathways, patient satisfaction, quality of life (QoL), and utilization of health care resources and the corresponding costs. The PREFER in VTE registry has been designed to address this and to understand medical care and needs as well as potential gaps for improvement. Methods/design: The PREFER in VTE registry was a prospective, observational, multicenter study conducted in seven European countries including Austria, France Germany, Italy, Spain, Switzerland, and the UK to assess the characteristics and the management of patients with VTE, the use of health care resources, and to provide data to estimate the costs for 12 months treatment following a first-time and/or recurrent VTE diagnosed in hospitals or specialized or primary care centers. In addition, existing anticoagulant treatment patterns, patient pathways, clinical outcomes, treatment satisfaction, and health related QoL were documented. The centers were chosen to reflect the care environment in which patients with VTE are managed in each of the participating countries. Patients were eligible to be enrolled into the registry if they were at least 18 years old, had a symptomatic, objectively confirmed first time or recurrent acute VTE defined as either distal or proximal deep vein thrombosis, pulmonary embolism or both. After the baseline visit at the time of the acute VTE event, further follow-up documentations occurred at 1, 3, 6 and 12 months. Follow-up data was collected by either routinely scheduled visits or by telephone calls. Results: Overall, 381 centers participated, which enrolled 3,545 patients during an observational period of 1 year. Conclusion: The PREFER in VTE registry will provide valuable insights into the characteristics of patients with VTE and their acute and mid-term management, as well as into drug utilization and the use of health care resources in acute first-time and/or recurrent VTE across Europe in clinical practice. Trial registration: Registered in DRKS register, ID number: DRKS0000479
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