170,234 research outputs found
ACTIVATION OF PARTIAL SEIZURES WITH MOTOR SIGNS DURING CYCLIC ALTERNATING PATTERN IN HUMAN SLEEP
No full textParaplegia spastica ereditaria, epilessia e ritardo mentale: Descrizione di nuove famiglie
No full textActivation of partial seizures with motor signs during cyclic alternating pattern in human sleep.
No full textBoth interictal and ictal EEG phenomena are commonly activated by functional instability. The different non-REM sleep stages comprise long-lasting periods of cyclic alternating pattern (CAP) in which arousal fluctuates between 'A phases' of greater arousal and 'B phases' of less arousal, and periods in which vigilance maintains a tonic stability (non-CAP). Previous studies have revealed that phase A induces a marked enhancement of generalized EEG paroxysms, a minor though significant activation of focal lesional bursts, but no effect on rolandic functional spikes. Conversely, phase B exerts an inhibitory modulation, especially on bilateral interictal phenomena. Because of the opposite influence of phase A and phase B also on muscle tone, we assessed the amount and distribution of nocturnal partial motor seizures in 6 subjects affected by focal epilepsy. The polysomnograms included 45 motor seizures, 43 of which occurred during non-REM sleep. Nocturnal fits were significantly more frequent in stages 1 and 3 (P less than 0.0001). Among the non-REM seizures, 42 appeared in CAP (P less than 0.0001) and always in phase A. The transient arousal and the concomitant muscle tone activation expressed by phase A of CAP is likely to support the motor components of nocturnal seizures. Sleep analysis in terms of CAP and non-CAP provides a better understanding of the continuum from subclinical EEG paroxysms to clinical manifestations and of the relations between vigilance and seizure disorders
Le etiologie infiammatorie nelle epilessie della casistica del Centro Regionale di Vicenza
No full textTransesterification of Bis(2-Ethylhexyl) Phthalate for the Recycling of Flexible Polyvinyl Chloride Scraps in the Circular Economy Framework
No full textThe identification of suitable process solutions for the recycling of plastics is nowadays one of the main challenges to reduce their environmental impact and promote their sustainability. In this context, the recycling of flexible polyvinyl chloride (PVC) has severe limitations because this material can contain bis(2-ethylhexyl) phthalate (DEHP), a plasticizing additive recently banned by the European Chemicals Agency (ECHA) due to its endocrine disruptor effect. In this study, we investigated a transesterification process for the possible conversion of DEHP to other less toxic phthalates applicable in the context of PVC mechanical recycling using a selective dissolution process. Different catalytic routes have been tested to find optimal concentrations for pure DEHP conversion and applied under real process conditions. Best results have been obtained at 80 °C with tetrabutyl titanate [Ti(OBu)4], using alcohol/DEHP molar ratios from 10:1 to 5:1, with conversions of more than 90% for pure DEHP in 15 min. However, limitations are related to the final conversion of DEHP in the presence of the PVC phthalate mixture, ranging between 57 and 60% after 90 min for the Ti(OBu)4catalyst. Such results are ascribed to dilution for complete PVC dissolution and the preferential formation of monosubstituted phthalates
Theoretical Studies of the RSOO, ROSO, RSO2 and HOOS (R = H, CH3) Radicals
No full textArticle on theoretical studies of the RSOO, ROSO, RSO2 and HOOS (R=H, CH3) radicals
Predictive Tools to Assist the Development of Flame Retarded Phosphorus-Free Polypropylene and Identify Synergy between Flame Retardants
No full textThe development of flame-retarded polypropylene is carried out with the ultimate goal of obtaining a UL94-V0 not only halogen- but also phosphorus-free formulation because phosphate rocks, precursors of phosphorus-based flame retardants, are recognized as critical raw materials within Europe. Different flame retardants (FRs) (melamine, phosphate ester, and radical generator) are used. A statistical approach is applied to predict UL94 behavior and develop optimized formulations in terms of cost, filler or phosphorus content. Models for most common "nondripping" as well as "nonflaming dripping" UL94-V0 behavior are proposed. The experimental validation has shown the reliability of the models proposed and their usefulness to assist and speed up the development of optimized formulations. The use of the models also gives insight into the interactions between flame retardants, thus suggesting if potential synergies take place, before studying the FRs system in details. Indeed, synergies between melamine and phosphate ester as well as melamine and radical generator are discovered. Thanks to these synergies that V0 rating can be achieved. A UL94-V0 formulation, comprising melamine and radical generator, is identified as the optimal halogen- and phosphorus-free formulation with a reduced filler content
Quantitative electrical homogeneity assessment of nanowire transparent electrodes
No full textThe homogeneous distribution of electric current (electrical homogeneity) is not guaranteed in nanowire electrodes but is crucial for the stability of the electrode and actually desirable in most applications. Despite the relevance of this feature, it is common practice to perform qualitative assessments at the electrode scale, thus masking local effects. To address this issue, we have developed a computational strategy to aid in the design of nanowire electrodes with improved electrical homogeneity. Nanowire electrodes are modeled as two-dimensional networks of stick and junction resistors (with resistance R-w and R-j, respectively) to simulate the electric conduction process. Electrodes are discretized into regular grids of squares and the electrical power of the network contained in each square is computed. The mismatch between the areal power density of the entire electrode and that of the squares provides a quantitative electrical homogeneity evaluation. Repeating the analysis with squares of different size yields an evaluation that spans across length scales. A scalar indicator, coined the homogeneity index, summarizes the results of the multiscale evaluation. The proposed strategy is employed to assess the electrical homogeneity of silver nanowire electrodes through the analysis of scanning electron microscopy images. Our results agree with the outcomes of the experimental assessment performed on the same electrodes. Parametric studies are performed by varying nanowire content and nanowire-to-junction resistance ratio R-w/R-j. We observe that a significant reduction of contact resistance is not necessary to ensure a high degree of homogeneity. The ideal condition of negligible junction resistance (R-w >> R-j) leads to the best-case scenario, a situation which is closely approached if R-w approximate to R-j (15% difference at the most in terms of homogeneity index)
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