18,771,268 research outputs found
Layer-by-Layer coated tyrosinase: An efficient and selective synthesis of catechols
No full textAgaricus bisporous tyrosinase was immobilized on commercial available epoxy-resin Eupergit (R) C250L and then coated by the Layer-by-Layer method (LbL). The two novel heterogeneous biocatalysts were characterized for their morphology, pH and storage stability, kinetic properties (K-m, V-max, V-max/K-m) and reusability. These biocatalysts were used for the efficient and selective synthesis of bioactive catechols under mild and environmental friendly experimental conditions. Ascorbic acid was added in the reaction medium to inhibit the formation of ortho-quinones, thus avoiding the known enzyme suicide inactivation process. Catechols were obtained mostly in quantitative yields and conversion of substrate. Tyrosinase immobilized on Eupergit (R) C250L and coated by the LbL method showed better catalytic activities, higher pH and storage stability, and reusability with respect to immobilized uncoated tyrosinase. Since chemical procedures to synthesize catechols are often expensive and with high environmental impact, the use of immobilized tyrosinase represents an efficient alternative for the preparation of this family of bioactive compounds. (C) 2011 Elsevier Ltd. All rights reserved
Dye Degradation by Layer by Layer Immobilized Peroxidases/Redox Mediator Systems
No full textHorseradish peroxidase (HRP) was immobilised on Eupergit C250L resin coated with poly-electrolytes, or by entrapment inside pre-formed layer-by-layer (LbL) micro-capsules of poly-electrolytes. In these systems, namely HRP/E-LbL, HRPm/LbL and HRPm/LbLp, the native enzyme retained its catalytic activity. Immobilised HRP showed a significant activity in the oxidation of selected azo, quinoline and fluorone dyes with H2O2 as the primary oxidant under mild experimental conditions, and HRPm/LbL was the best catalyst. A comparison between the catalytic efficiency of different redox mediators for HRP activity was made by using 1-hydroxybenzotriazole (HOBt), violuric acid (VLA) and veratrylic alcohol (VA). As a general trend, azo dyes were degraded in higher yields, and HOBt was the best mediator for the oxidation. The degradation yield increased on increasing the reaction time and reached the highest value after 12h, which is comparable with that observed for native HRP. Notably, HRPm/LbL retained its catalytic activity for more runs
Emotional mapping of museum augmented places
No full textIl mobile e ubiquitous learning è stato messo in relazione alle nuove tecnologie dell’informazione e della comunicazione che si trovano incorporate negli oggetti della vita quotidiana. Una varietà invisibile di strumenti integrati sono stati sviluppati e collegati a Internet. I confini tra apprendimento, gioco, simulazione o giochi di ruolo non sono chiaramente definiti. Ne consegue che anche una visita in luoghi di interesse culturale (es. musei, parchi archeologici, città storiche, trekking urbani ecc.), utilizzando uno smartphone o un tablet, potrebbe offrire un’esperienza educativa unica come descritto nelle sperimentazioni del format EMMAP (Emotional Mapping of Museum Augmented Places) presso il Museo Civico Archeologico "Giuseppe Moretti" di San Severino Marche, il Museo della Carrozza di Macerata e la passeggiata attorno alle mura urbiche di Macerata, per osservare la mostra “Poesia di Strada” in realtà aumentata.
EMMAP è un format didattico che mira a sviluppare pedagogie innovative, utilizzando la tecnologia portatile, combinata con i codici QR, il broadcast e la realtà aumentata. Questi strumenti sono utili alla creazione di ambienti mobili e ubiqui di apprendimento idonei al coinvolgimento emotivo dei partecipanti in situazione di apprendimento autentico
A double-blind comparative study of the safety and efficacy of iomeprol in renal intra-arterial digital subtraction angiography
No full textThis randomised, double-blind, parallel group study was to compare the safety, tolerance and diagnostic efficacy of iomeprol and iopamidol, both at an iodine concentration of 150 mgI/ml, in 40 patients with arterial hypertension who required renal intraarterial digital subtraction angiography (IA-DSA) for suspected renovascular stenosis. All patients underwent extensive pre- and post-contrast clinical, instrumental and laboratory controls for safety assessments. The tolerance to the test contrast media was evaluated in terms of discomfort associated with the injection of the test compounds. Image quality was prospectively graded by two independent readers according to a five-point scale as follows: 1, insufficient; 2, sufficient; 3, good; 4, excellent; E, excessive. The quality of vascular opacification in the region of interest was rated as diagnostic in 87.8% of radiographs obtained in the iomeprol group and in 84.5% in the iopamidol group, without significant differences between the two study groups. The results of angiography were always useful for subsequent patient management. The procedure was always well tolerated. There were no clinically significant changes in vital signs, ECG and laboratory parameters during the study in both groups. The results of our study show that iomeprol 150 mgI/ml, and iopamidol 150 mgI/ml are equally effective, well tolerated and safe contrast agents when used for IA-DSA
Emotional Mapping of a Place of Interest using Mobile Devices for Learning.
No full textProceedings of IADIS International Conference - Mobile Learning 2011 Avila (Spain
Four years' follow-up results of three different percutaneous treatments for male varicocele
No full textObjective: To evaluate the efficacy of three different interventional radiological procedures for the treatment of venous reflux in symptomatic male varicocele. Design: Prospective study with a 48-month colour duplex ultrasound (CD) follow-up. Setting: Department of Radiology, Tor Vergata University of Pome. Patients: From January 1991 to December 1993, 45 symptomatic patients with third- to fourth-degree varicocele, according to Sarteschi's CD classification, were randomly divided into three equal groups (15 patients each). Interventions: The first group received sclerotherapy (Athoxysclerol), the second underwent embolisation (Gianturco coils), while the third group received combined sclero-embolisation therapy (Athoxysclerol and Gianturco coils). Main outcomes measures: The frequency of recurrence for each procedure. Results: Two recurrences (13%) after 1 and 2 years occurred in patients who underwent sclerotherapy. In the embolisation group, two patients showed residual varices (13%). Neither recurrence nor-residue was seen in the third group, who received combined therapy. Conclusions: Sclerotherapy provides good immediate results but drug dilution may cause a relapse shortly after treatment. Embolisation has a lower immediate success but better long-term success. Combined treatment provides the highest long-term success-rate
A novel and efficient oxidative functionalization of lignin by layer-by-layer immobilised Horseradish peroxidase
No full textHorseradish peroxidase (HRP) was chemically immobilised onto alumina particles and coated by polyelectrolytes layers, using the layer-by-layer technique. The reactivity of the immobilised enzyme was studied in the oxidative functionalisation of softwood milled wood and residual kraft lignins and found higher than the free enzyme. In order to investigate the chemical modifications in the lignin structure, quantitative 31P NMR was used. The immobilised HRP showed a higher reactivity with respect to the native enzyme yielding extensive depolymerisation of lignin
Representation and knowledge of historic construction: HBIM for structural use in the case of Villa Palma-Guazzaroni in Terni
No full textA validated method for the digital representation of historic construction through HBIM permits assessment of compliance with workmanlike practices and structural performance. The construction of an appropriate model is closely linked to survey methodology, to the integrated application of multiple techniques of direct and indirect survey and non-destructive tests. The paper specifically deals with the complementarity between photogrammetry based on UAV (Unmanned Aerial Vehicles) with TLS (Terrestrial Laser Scanner). Finally, through this methodology, the HBIM model set for structural use allows the analysis of local mechanisms in order to verify the performance of the building. The methodological approach to the relationship between constructive survey and construction of the HBIM model to understand and evaluate the building organism from a structural point of view is exposed using Villa Palma-Guazzaroni in Terni as a case study. The Villa is representative of architectural heritage resulting from an original unitary intervention and subsequently affected by several modifications that, without obscuring many of the original values, have nevertheless altered the building and its architectural characteristics
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