Tomographie par diffusion Rayleigh et Compton avec reconstruction numérique de l'image

La diffusion des rayons X par effets Rayleigh et Compton permet d'obtenir des tomographies de la matière inerte ou vivante. Nous décrivons un nouveau système d'acquisition en tomographie par diffusion et sa méthode de reconstruction. Le déplacement de l'objet est similaire à celui utilisé avec les tomographes de première génération. Un algorithme de reconstruction standard donne deux images intermédiaires, correspondant aux contributions Rayleigh et Compton. Des artefacts de type "cupping effect", dûs à l'auto-atténuation des photons dans l'échantillon, sont présents sur chacune de ces deux images. En faisant le rapport de ces deux images intermédiaires, on obtient une cartographie, dénuée de tout artefact, représentant le numéro atomique local de l'objet contrôlé, indépendamment de sa densité. Les expériences ont été réalisées à 1'ESRF (European Synchrotron Radiation Facility) de Grenoble, sur la ligne ID 15 B. L'important flux de photons monochromatiques (1012 ph.s-1.mm-2) permet d'obtenir des temps d'acquisition courts (quelques secondes par mesure) et d'avoir une bonne résolution spatiale. La taille du voxel est de 1x1 mm2 dans le plan de coupe pour une épaisseur de coupe de 0,3 mm.The detection of X-ray photons scattered through a sample by the Rayleigh and Compton processes is used to perform tomographic images. We describe a new experimental arrangement and the corresponding reconstruction method. The scanning method is similar to the one used for first generation tomographs. A standard reconstruction algorithm gives two intermediate images, corresponding to the Compton and Rayleigh contributions. On both images artifacts are present, due to photon attenuation in the sample. Dividing those two images produces a map, free from artifacts, which represents the atomic number Z, independently from density. The experiments were carried out at the European Synchrotron Radiation Facility (ESRF), in Grenoble (France), on line ID15 B. Due to the very high photon flux (1012 ph.s-1.mm-2), short measurement times (about a few seconds per point) are allowed, as well as a good spatial resolution. The voxel size is 1 x 1 mm2 in the plane of the slice and 0.3 mm in the third direction

Conception of a high resolution x‐ray computed tomography device; application to damage initiation imaging inside materials

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Pharmacokinetics of pitolisant in children and adolescents with narcolepsy

Objective: To evaluate the pharmacokinetic profile and tolerability of pitolisant, a selective histamine 3 (H3) 12receptor antagonist/inverse agonist, in children and adolescents with narcolepsy. Methods: This multicenter, open-label, single-dose study of pitolisant 17.8 mg enrolled patients aged 6 through 17 years with a diagnosis of narcolepsy. Blood samples were collected at prespecified time points for analysis of pharmacokinetic parameters, including maximum serum concentration (Cmax) and area under the serum concentration\u2013time curve from time 0\u201310 h (AUC0\u201310h). Pharmacokinetic parameters were compared across three prespecified age groups: younger pediatric patients (aged 6 to <12 years), older pediatric patients (aged 12 to <18 years), and a historical comparison group of young adults (aged 18 to <45 years). Results: Of the 25 enrolled patients, 24 were included in the pharmacokinetic analysis. Pitolisant Cmax and AUC0\u201310h were greater (by 52% and 73%, respectively) in the younger (n = 12) versus older (n = 12) pediatric subgroup. These parameters were lower in the young adult group (n = 13) by 51% and 48%, respectively, compared with the older pediatric patients, and by 68% and 70%, respectively, compared with the younger pediatric patients. There were six treatment-emergent adverse events: headache (three), dizziness (one), diarrhea (one), and vomiting (one). Conclusions: After single-dose administration, the exposure parameters of pitolisant were significantly greater in the younger compared with older pediatric patients with narcolepsy. Pitolisant doses up to 17.8 mg/d (in children with body weight <40 kg) or 35.6 mg/d are appropriate for further evaluation in pediatric patients. Trial registration: EudraCT Number: 2013-001505-93

Real-time hybrid simulation facility for PV inverter testing

International audienc

Pharmacokinetics of pitolisant in children and adolescents with narcolepsy

Objective: To evaluate the pharmacokinetic profile and tolerability of pitolisant, a selective histamine 3 (H3)−receptor antagonist/inverse agonist, in children and adolescents with narcolepsy. Methods: This multicenter, open-label, single-dose study of pitolisant 17.8 mg enrolled patients aged 6 through 17 years with a diagnosis of narcolepsy. Blood samples were collected at prespecified time points for analysis of pharmacokinetic parameters, including maximum serum concentration (Cmax) and area under the serum concentration–time curve from time 0–10 h (AUC0–10h). Pharmacokinetic parameters were compared across three prespecified age groups: younger pediatric patients (aged 6 to <12 years), older pediatric patients (aged 12 to <18 years), and a historical comparison group of young adults (aged 18 to <45 years). Results: Of the 25 enrolled patients, 24 were included in the pharmacokinetic analysis. Pitolisant Cmax and AUC0–10h were greater (by 52% and 73%, respectively) in the younger (n = 12) versus older (n = 12) pediatric subgroup. These parameters were lower in the young adult group (n = 13) by 51% and 48%, respectively, compared with the older pediatric patients, and by 68% and 70%, respectively, compared with the younger pediatric patients. There were six treatment-emergent adverse events: headache (three), dizziness (one), diarrhea (one), and vomiting (one). Conclusions: After single-dose administration, the exposure parameters of pitolisant were significantly greater in the younger compared with older pediatric patients with narcolepsy. Pitolisant doses up to 17.8 mg/d (in children with body weight <40 kg) or 35.6 mg/d are appropriate for further evaluation in pediatric patients. Trial registration: EudraCT Number: 2013-001505-93

Répartition des souches A2 de Phytophthora infestans en France en 1996

International audienc

Le traitement ciblé-sélectif des bovins, ovins et caprins contre les strongles gastro-intestinaux

Les ruminants pâturant sont systématiquement infestés par des strongles gastro-intestinaux. Quelle que soit la filière, la réponse est souvent l’utilisation insuffisamment raisonnée d’anthelminthiques, ce qui entraine le développement de vers résistants. Aujourd’hui, il est donc nécessaire de mieux utiliser ces traitements. Le projet visait à répondre aux deux questions majeures « quand traiter » et « qui traiter » chez les vaches laitières, les ovins et les caprins, et à comprendre les motivations des éleveurs et des conseillers. Il apparait que, pour les vaches laitières, il serait préférable de traiter à la rentrée en stabulation uniquement les jeunes vaches insuffisamment immunisées et fortement exposées aux parasites au pâturage. Pour les petits ruminants, la coproscopie de mélange permet une bonne estimation du niveau d’excrétion d’un lot d’animaux et de cibler le moment d’intervention. De plus, au niveau individuel, les critères utilisés par les éleveurs de chèvres permettent de sélectionner correctement les animaux à traiter. Pour les bovins et les caprins, les périodes à risque parasitaire au pâturage peuvent être estimées grâce à un système expert. Enfin, il ressort que les acteurs de la filière bovine sont moins sensibilisés au traitement ciblé-sélectif que ceux de la filière caprine, mais leur sensibilisation est possible.Grazing ruminants are always infested by gastrointestinal nematodes. Whatever the animal supply chain, the answer is often an insufficiently reasoned use of anthelmintics, which involves a development of resistant parasites. Nowadays, it is necessary to better use these treatments. The project aimed at answering two major questions: “when to treat” and “who to treat” in dairy cows, sheep and goats, and to understand motivations of farmers and advisers. It appears that, for dairy cows, it would be better to treat at the beginning of the housing period, only inadequately immunized young cows that are severely exposed to parasites in pasture. For small ruminants, the mixing coproscopy provides a good estimation of the level of excretion of a group of animals and enables to target the time of intervention. Moreover, at the individual level, the criteria used by goat and cow farmers permit to correctly select animals to be treated. For cattle and goats, grazing parasitic risk periods can be estimated by an expert system. A. Duvauchelle-Waché et al. 136 Innovations Agronomiques 55 (207), 135-153 Finally, it appears that actors of the cattle industry are less aware of the targeted-selective treatment than the goat sector, but raising their awareness is possible