Influence of layered double hydroxide (LDH) lateral size on corrosion resistance of AZ31 Mg alloy

peer reviewe

Replication Validity of Initial Association Studies:A Comparison between Psychiatry, Neurology and Four Somatic Diseases

CONTEXT:There are growing concerns about effect size inflation and replication validity of association studies, but few observational investigations have explored the extent of these problems. OBJECTIVE:Using meta-analyses to measure the reliability of initial studies and explore whether this varies across biomedical domains and study types (cognitive/behavioral, brain imaging, genetic and "others"). METHODS:We analyzed 663 meta-analyses describing associations between markers or risk factors and 12 pathologies within three biomedical domains (psychiatry, neurology and four somatic diseases). We collected the effect size, sample size, publication year and Impact Factor of initial studies, largest studies (i.e., with the largest sample size) and the corresponding meta-analyses. Initial studies were considered as replicated if they were in nominal agreement with meta-analyses and if their effect size inflation was below 100%. RESULTS:Nominal agreement between initial studies and meta-analyses regarding the presence of a significant effect was not better than chance in psychiatry, whereas it was somewhat better in neurology and somatic diseases. Whereas effect sizes reported by largest studies and meta-analyses were similar, most of those reported by initial studies were inflated. Among the 256 initial studies reporting a significant effect (p<0.05) and paired with significant meta-analyses, 97 effect sizes were inflated by more than 100%. Nominal agreement and effect size inflation varied with the biomedical domain and study type. Indeed, the replication rate of initial studies reporting a significant effect ranged from 6.3% for genetic studies in psychiatry to 86.4% for cognitive/behavioral studies. Comparison between eight subgroups shows that replication rate decreases with sample size and "true" effect size. We observed no evidence of association between replication rate and publication year or Impact Factor. CONCLUSION:The differences in reliability between biological psychiatry, neurology and somatic diseases suggest that there is room for improvement, at least in some subdomains

Study of formation and corrosion resistance of Ce-doped ZnAl hydrotalcite layers on different zinc alloys coated steel

peer reviewedDue to their unique structure, hydrotalcite (HT) can trap and hold aggressive corrosive anions in their positively charged layers [1]. Moreover, hydrotalcite can be directly grown on the metal surface and form a physical protective layer avoiding the exposure of substrate to corrosive environments [2]. Recently, various methods have been investigated to prepare HT layers as smart anti-corrosion coatings on surfaces of zinc alloys and galvanized steel [3, 4]. However, the preparation and corrosion resistance assessment of “in-situ” La/Ce-doped HT layer on galvanized steel substrates have not been still well investigated. This study aims at investigating the influence of composition and roughness of the zinc coated steel substrates such as hot-dip galvanized steel, Zn-Al coated steel, and Zn-Al-Mg coated steel substrates on the formation and the anti-corrosion properties of Ce-doped ZnAl HT layers grown by the “in-situ” synthesis method at pH 12. The structural and morphological properties of Ce-doped ZnAl HT layers were detected by Fourier-transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and electron microscopy/energy dispersive X-ray spectroscopy. The corrosion behaviour of layers was recorded by electrochemical methods such as potentiodynamic polarization and electrochemical impedance spectroscopy during 168 h immersion in sodium chloride (0.1 M). Besides, the inhibitive effect of Ce-doped ZnAl HT layers on all corrosion substrates was discussed in detail.4617 - ARES PRD 2020 - Vietnam - Renforcement de l'expertise du centre de compétences en protection contre la corrosion et en éléctrochimie - Fédération Wallonie Bruxelles9. Industry, innovation and infrastructur

Correlating corrosion modes with the microstructure of the 2XXX series alloys: A comparative approach

peer reviewedIn this study, the localized corrosion susceptibility of AA2050-T84, AA2198-T851, and AA2024-T3 alloys was compared by immersion in three test solutions, specifically sodium chloride solution (3.5% NaCl), EXCO solution, according to ASTM G34-18, and a solution for intergranular corrosion (IGC) test recommended by ASTM G110-15 and via scanning vibrating electrode technique (SVET). The results showed higher susceptibility of AA2050-T84 alloy to all types of corrosion tested compared to the other studied 2XXX series alloys. Corrosion penetration was deeper in the AA2050-T84 due to its microstructural characteristics as a difference in the micrometric Cu-Rich intermetallic particle distribution on the surface and related to the distribution of the T1 (Al2CuLi) phase.9. Industry, innovation and infrastructur

How French media have portrayed ADHD to the lay public and to social workers

Two models of attention deficit hyperactivity disorder (ADHD) coexist: the biomedical and the psychosocial. We identified in nine French newspapers 159 articles giving facts and opinions about ADHD from 1995 to 2015. We classified them according to the model they mainly supported and on the basis of what argument. Two thirds (104/159) mainly supported the biomedical model. The others either defended the psychodynamic understanding of ADHD or voiced both models. Neurological dysfunctions and genetic risk factors were mentioned in support of the biomedical model in only 26 and eight articles, respectively. These biological arguments were less frequent in the most recent years. There were fewer articles mentioning medication other than asserting that medication must be combined with psychosocial interventions (14 versus 57 articles). Only 11/159 articles claimed that medication protects from school failure. These results were compared to those of our two previous studies. Thus, both French newspapers and the specialized press read by social workers mainly defended either the psychodynamic understanding of ADHD or a nuanced version of the biomedical model. In contrast, most French TV programmes described ADHD as an inherited neurological disease whose consequences on school failure can be counteracted by a very effective medication

Les usages de la micro-informatique et d'internet dans les écoles primaires francophones

International audienceLe présent article se propose d'apporter un éclairage sur les pratiques pédagogiques en matière d'utilisation de la micro-informatique à l'école. A partir d'un sous-ensemble particulier d'écoles, à savoir des écoles primaires francophones disposant en 1998 d'une connexion Internet, une enquête a été réalisée pour conna\ⁱtre les enseignants qui sont à l'origine de cette connexion, leurs pratiques informatiques personnelles, les pratiques qu'ils encadrent à l'école et le poids de ces pratiques au sein des activités d'apprentissage traditionnelles. Il en ressort que les activités informatiques des élèves francophones sont fortement dépendantes de l'intérêt que leur enseignant manifeste pour les technologies de l'information et de la communication dans l'enseignement (TICE), intérêt individuel avant tout, qui semble peu devoir à l'environnement scolaire

Contrôle de la libération et de l'élimination de la dopamine par la recapture et les autorécepteurs (études par électrochimie in vivo dans le striatum)

Nous avons étudié deux mécanismes contrôlant la dopamine extracellulaire : l'autorégulation et la recapture par son transporteur (DAT). L'efflux de dopamine évoqué par des stimulations électriques a été enregistré dans le striatum et le noyau accumbens par ampérométrie continue chez la souris anesthésiée. Nous avons montré in vivo que le DAT est le seul mécanisme d'élimination de la dopamine, et qu'il permet la reconstitution du stock de dopamine libérable. Les neurones dopaminergiques présentent une activité tonique à 4 Hz, et une activité phasique en bouffées à 15 Hz. Chez l'animal normal, seules les bouffées entraînent une accumulation de la dopamine extracellulaire. Chez les souris sans DAT, la dopamine s'accumule aussi lors de l'activité tonique. L'expression différentielle des activités tonique et phasique, en termes de dopamine extracellulaire, dépend donc du DAT. Nous avons montré que la recapture limite la distance de diffusion de la dopamine à 7(micron)m. La dopamine extracellulaire agit sur des autorécepteurs D2 présynaptiques qui inhibent sa propre libération. Nous avons précisé le décours temporel de cette inhibition (maximum à 0,2 s et durée de 0,6 s) et nous avons montré que l'activation des autorécepteurs nécessite l'accumulation de dopamine extracellulaire. Ces caractéristiques sont typiques des récepteurs couplés aux protéines G. L'autoinhibition limite le taux de dopamine extracellulaire durant une bouffée et la quantité de dopamine libérée par un potentiel d'action suivant une bouffée. Toutefoi_s, par rapport à la recapture, l'autorégulation ne joue qu'un rôle secondaire de régulateur fin. L'autorégulation est diminuée en absence du DAT, et non l'inverse. De plus, des altérations postsynaptiques de la transmission dopaminergique n'induisent pas d'adaptation présynaptique. Il semble donc que seule une atteinte directe de la recapture altère de façon majeure l'expression de la transmission dopaminergique en termes de dopamine extracellulaire.BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF