Влияние состояния TiO2 на окислительную делигнификацию древесины осины и соломы пшеницы

The influence of preparation methods on structural characteristics of TiO2 catalysts was studied by the XRD, SEM, BET, DTA-DSC, FTIR techniques. Catalytic activity of obtained titanium dioxide samples was compared in reaction of oxidative delignification of aspen wood and wheat straw by hydrogen peroxide in acetic acid- water medium. The use of titanium dioxide in rutile modification allows to produce a cellulose product with lower content of a residual lignin, as compared to TiO2 in anatase modification. The increase of surface area of the TiO2 catalyst reduces its activity in wood and wheat straw delignificationМетодами РФА, СЭМ, БЭТ, ДТА-ДСК, ИКС изучено влияние способов получения катализаторов TiO2 на их структурные характеристики. Сопоставлена каталитическая активность полученных образцов диоксида титана в реакции окислительной делигнификации древесины осины и соломы пшеницы пероксидом водорода в среде «уксусная кислота–вода». Использование диоксида титана в модификации рутил позволяет получить целлюлозный продукт с более низким содержанием остаточного лигнина, чем при использовании TiO2 в модификации анатаз. Увеличение удельной поверхности катализатора приводит к уменьшению степени делигнификации древесины осины и соломы пшениц

Effets comparatifs des acides gras omega-3 (ALA, EPA, DHA) sur la sensibilité à l’insuline des cellules musculaires C2C12 dans un contexte lipotoxique

Objectifs :Etudier le rôle des ω3 sur la lipotoxicité induite par l’acide gras saturé palmitate (PAL, C16:0) dans un modèle de cellule musculaire C2C12.Identifier les effets propres de chaque w3 (ALA, EPA et DHA) à dose équivalente sur la fluidité des membranes et la réponse à l’insuline.Suivre le devenir intracellulaire du [1-14C]-palmitate en présence d’un w3 et définir les classes de lipides altérées.Rechercher les voies de signalisation impliquées dans la modulation de la réponse à l’insuline

A Novel Sparse Graphical Approach for Multimodal Brain Connectivity Inference

International audienceDespite the clear potential benefits of combining fMRI and diffusion MRI in learning the neural pathways that underlie brain functions, little methodological progress has been made in this direction. In this paper, we propose a novel multimodal integration approach based on sparse Gaussian graphical model for estimating brain connectivity. Casting functional connectivity estimation as a sparse inverse covariance learning problem, we adapt the level of sparse penalization on each connection based on its anatomical capacity for functional interactions. Functional connections with little anatomical support are thus more heavily penalized. For validation, we showed on real data collected from a cohort of 60 subjects that additionally modeling anatomical capacity significantly increases subject consistency in the detected connection patterns. Moreover, we demonstrated that incorporating a connectivity prior learned with our multimodal connectivity estimation approach improves activation detection

How caldera collapse shapes the shallow emplacement and transfer of magma in active volcanoes

Calderas are topographic depressions formed by the collapse of a partly drained magma reservoir. At volcanic edifices with calderas, eruptive fissures can circumscribe the outer caldera rim, be oriented radially and/or align with the regional tectonic stress field. Constraining the mechanisms that govern this spatial arrangement is fundamental to understand the dynamics of shallow magma storage and transport and evaluate volcanic hazard. Here we show with numerical models that the previously unappreciated unloading effect of caldera formation may contribute significantly to the stress budget of a volcano. We first test this hypothesis against the ideal case of Fernandina, Galápagos, where previous models only partly explained the peculiar pattern of circumferential and radial eruptive fissures and the geometry of the intrusions determined by inverting the deformation data. We show that by taking into account the decompression due to the caldera formation, the modeled edifice stress field is consistent with all the observations. We then develop a general model for the stress state at volcanic edifices with calderas based on the competition of caldera decompression, magma buoyancy forces and tectonic stresses. These factors control: 1) the shallow accumulation of magma in stacked sills, consistently with observations; 2) the conditions for the development of circumferential and/or radial eruptive fissures, as observed on active volcanoes. This top-down control exerted by changes in the distribution of mass at the surface allows better understanding of how shallow magma is transferred at active calderas, contributing to forecasting the location and type of opening fissures

Sources of experimental errors in the observation of nanoscale magnetism

It has been recently reported that some non-magnetic materials in bulk state, exhibit magnetic behavior at the nanscale due to surface and size effects. The experimental observation of these effects is based on the measurement of very small magnetic signals. Thus, some spurious effects that are not critical for bulk materials with large magnetic signals may become important when measuring small signals (typically below 0.0001 emu). Here, we summarize some sources of these small magnetic signals that should be considered when studying this new nanomagnetismComment: 16 pages, 10 figure

Effective connectivity reveals strategy differences in an expert calculator

Mathematical reasoning is a core component of cognition and the study of experts defines the upper limits of human cognitive abilities, which is why we are fascinated by peak performers, such as chess masters and mental calculators. Here, we investigated the neural bases of calendrical skills, i.e. the ability to rapidly identify the weekday of a particular date, in a gifted mental calculator who does not fall in the autistic spectrum, using functional MRI. Graph-based mapping of effective connectivity, but not univariate analysis, revealed distinct anatomical location of “cortical hubs” supporting the processing of well-practiced close dates and less-practiced remote dates: the former engaged predominantly occipital and medial temporal areas, whereas the latter were associated mainly with prefrontal, orbitofrontal and anterior cingulate connectivity. These results point to the effect of extensive practice on the development of expertise and long term working memory, and demonstrate the role of frontal networks in supporting performance on less practiced calculations, which incur additional processing demands. Through the example of calendrical skills, our results demonstrate that the ability to perform complex calculations is initially supported by extensive attentional and strategic resources, which, as expertise develops, are gradually replaced by access to long term working memory for familiar material

Impact of Neuromyelitis Optica Spectrum Disorder on Quality of Life from the Patients' Perspective : An Observational Cross-Sectional Study

Altres ajuts: Medical Department of Roche Farma, Spain (ML41397).Introduction: Neuromyelitis optica spectrum disorder (NMOSD) is associated with a reduced health-related quality of life (HRQoL). The purpose of this study was to describe the impact of NMOSD on HRQoL from the patients' perspective and its relationship with other disease factors. Methods: An observational, cross-sectional study was conducted at 13 neuroimmunology clinics in Spain. Patients with NMOSD diagnosis (2015 Wingerchuk criteria) were included. The 29-item Multiple Sclerosis Impact Scale (MSIS-29) was used to assess the HRQoL. Different questionnaires were used to measure symptom severity, stigma, mood disorders, pain, fatigue, and difficulties in the workplace. Factors that impact HRQoL were identified by Spearman's correlation and multivariate linear regression analysis. Results: Seventy-one patients were included (mean age 47.4 ± 14.9 years, 80.3% female, mean time since disease onset 9.9 ± 8.1 years). The median Expanded Disability Status Scale score was 3.0 (1.5-4.5). The mean (± SD) physical and psychological MSIS-29 sub-scores were 41.9 ± 16.8 and 20.9 ± 8.3, respectively. Fatigue and body pain were the most prevalent symptoms. Depressive symptoms were found in 44.3% (n = 31) of patients. The physical MSIS-29 dimension showed the highest correlation with symptom severity (ρ = 0.85584, p < 0.0001), whereas the highest correlations for psychological MSIS-29 dimension were pain, MSIS-29 physical dimension, and depression (ρ = 0.76487, 0.72779, 0.71380; p < 0.0001, respectively). Pain was a predictor of both dimensions of MSIS-29. Conclusion: Fatigue, pain, and depressive symptoms are frequent problems among patients with NMOSD, impacting on their quality of life. Assessment of patient-oriented outcomes may be useful to achieve a holistic approach, allowing early specific interventions

Unexpected large eruptions from buoyant magma bodies within viscoelastic crust

Large volume effusive eruptions with relatively minor observed precursory signals are at odds with widely used models to interpret volcano deformation. Here we propose a new modelling framework that resolves this discrepancy by accounting for magma buoyancy, viscoelastic crustal properties, and sustained magma channels. At low magma accumulation rates, the stability of deep magma bodies is governed by the magma-host rock density contrast and the magma body thickness. During eruptions, inelastic processes including magma mush erosion and thermal effects, can form a sustained channel that supports magma flow, driven by the pressure difference between the magma body and surface vents. At failure onset, it may be difficult to forecast the final eruption volume; pressure in a magma body may drop well below the lithostatic load, create under-pressure and initiate a caldera collapse, despite only modest precursors