Sol–gel processing and characterization of (RE-Y)-zirconia powders for thermal barrier coatings

The effect of doping on the structural, morphological and thermal properties of ZrO2–XO1.5 (X=Y, La, Sm, Er) solid solutions for thermal barrier (TBC) applications was investigated. Oxide powders of various compositions from 9.7 to 40 mol% XO1.5 (X=Y, La, Sm, Er) were synthesised by the sol–gel route. The structural analysis of the powders was performed using X-ray diffraction analysis coupled with Rietveld refinements and the measurement of their specific surface area with the BET method. For each rare earth dopant, the morphology of the powders varies from monoliths to agglomerates of thinner particles when the doping amount increases. In order to determine the specific heat, the thermal diffusivity at room temperature and the thermal expansion coefficient of some selected compositions, DSC, laser thermal diffusivity and hightemperature dilatometry measurements were performed on samples densified by Spark Plasma Sintering. Working thermal characterisation indicated that zirconia doped with 30 mol% SmO1.5 and ErO1.5 have better insulation properties and a lower thermal expansion coefficient than our reference YSZ ceramic. These various compositions are very promising for the elaboration of multilayer TBCs by the sol–gel process

Correlations between genotypic and cultural factors on protein and oil contents and fatty acids composition of soybean seeds

International audienc

Correlations between genotypic and cultural factors on protein and oil contents and fatty acid composition of soybean seeds

International audienc

Entre information et communication, les nouveaux espaces du document

Ce numéro s’inscrit dans la réflexion actuelle qui traverse les Sciences de l’Information et de la documentation autour de la notion de document, en rapport avec le développement des réseaux numériques. Le terme d’espaces est ici volontairement ambigu, car Études de Communication souhaite ouvrir un débat autour de cette notion à la fois quotidienne, technique et savante. Lorsqu’on parle d’Internet, les métaphores de l’espace se multiplient : outre les images rebattues liées à la navigation, au parcours, à l’exploration, il est question de cartes conceptuelles, de géographie des sites, mais aussi de profondeur, de dimension cachée... autant de termes qui ramènent à l’indexation et aux procédures de guidage dans l’univers des signes. Il semble quasi impossible d’élaborer une conception d’Internet sans recourir à des images mentales à caractère spatial. Les espaces réels, symboliques et imaginaires concernent à la fois la dimension cognitive du document, sa dimension technique et sa dimension sociale. En ce sens, étudier les espaces du document et/ou ses métamorphoses conduit à de multiples questionnements. Interrogations que se propose d’explorer le trentième numéro d’Études de Communication. This issue is part of the current reflection running through the information and documentation sciences concerning the notion of the document in relation to the development of digital networks. Use of the term “spaces” is voluntarily ambiguous because Études de Communications wants to open the debate on this idea that is at once routine, technical, and scholarly. When we speak about the Internet, metaphors of space are multiple: other than images borrowed from navigation, itineraries, or exploration, there is the question of conceptual maps, site geography, but also depth, hidden dimensions . . . terms that refer to the indexation of piloting procedures in the universe of signs. It seems almost impossible to discuss the idea of the Internet without recourse to mental images related to space. Real, symbolic, and imaginary spaces concern both the cognitive dimension of the document, and its technical and social dimensions. In this sense, studying the spaces of the document and/or its transformations leads to multiple questions which the thirtieth issue of Études de Communications intends to explore

Hydroxychloroquine levels in patients with systemic lupus erythematosus: whole blood is preferable but serum levels also detect non-adherence

International audienceBackground: Hydroxychloroquine (HCQ) levels can be measured in both serum and whole blood. No cut-off point for non-adherence has been established in serum nor have these methods ever been compared. The aims of this study were to compare these two approaches and determine if serum HCQ cut-off points can be established to identify non-adherent patients.Methods: HCQ levels were measured in serum and whole blood from 573 patients with systemic lupus erythematosus (SLE). The risk factors for active SLE (SLEDAI score > 4) were identified by multiple logistic regression. Serum HCQ levels were measured in 68 additional patients known to be non-adherent, i.e. with whole-blood HCQ < 200 ng/mL.Results: The mean (± SD) HCQ levels were 469 ± 223 ng/mL in serum and 916 ± 449 ng/mL in whole blood. The mean ratio of serum/whole-blood HCQ levels was 0.53 ± 0.15. In the multivariate analysis, low whole-blood HCQ levels (P = 0.023), but not serum HCQ levels, were independently associated with active SLE. From the mean serum/whole-blood level ratio, a serum HCQ level of 106 ng/mL was extrapolated as the corresponding cut-off to identify non-adherent patients with a sensitivity of 0.87 (95% CI 0.76-0.94) and specificity of 0.89 (95% CI 0.72-0.98). All serum HCQ levels of patients with whole-blood HCQ below the detectable level (< 20 ng/mL) were also undetectable (< 20 ng/mL).Conclusions: These data suggest that whole blood is better than serum for assessing the pharmacokinetic/pharmacodynamic relation of HCQ. Our results support the use of serum HCQ levels to assess non-adherence when whole blood is unavailable