Influence of flax fibers on network formation of DGEBA/DETA matrix

Natural fibers and particularly flax fibers have a great potential to replace glass fibers in composite materials. However, the interaction between these fibers and thermoset matrices remains unclear and results in a weak interface affecting the mechanical properties of the composite. This study was carried out to investigate the impact of natural fibers on the chemical reaction between the resin and the hardener, studying the interaction of fibers with each component separately to understand more precisely the phenomena involved. The results show that the contact with the fibers involves a change of the matrix properties that has been attributed to the water absorbed on their surface. On the one hand, water could modify amine functions of the hardener leading to a decrease of 40°C of matrix glass transition temperature (Tg). This issue could be corrected by adding a 16% excess of hardener. On the other hand, the water added to the resin could also accelerate the epoxide/amine reaction increasing slightly the Tg of the matrix and also generating weaker distinct networks of lower Tg by post-modification of the hardener. Therefore, the control of the water content in flax fibers is a crucial parameter for composite manufacturing

Évaluation et expérimentation de logiciels libres pour la petite et moyenne entreprise

Les logiciels libres, ou Open Source Software, ont connu un très grand succès au cours des dernières années. Les logiciels libres offrent plusieurs avantages à leurs utilisateurs: des coûts plus bas, davantage de flexibilité dans la conduite de leur stratégie informatique ainsi que la réduction de certains risques, tel que la disparition de l’éditeur d’un logiciel. Récemment, plusieurs logiciels d’affaires sont apparus sous licence libre: parmi ceux-ci, certains progiciels de gestion intégrée (PGI, ou ERP) se démarquent, dont Compiere, avec des centaines de milliers de références sur Google et un nombre total de plus de 700 000 téléchargements. Il est raisonnable de croire que les logiciels d’affaires libres offrent aux PME canadiennes l'opportunité de bénéficier des avantages des technologies de l'information à moindre coût. Nous soutenons que l’accès au gain d’efficience promis par ces logiciels à moindre coût pourrait augmenter la compétitivité des entreprises canadiennes. Ce projet est une première étape en vue de vérifier cette hypothèse. Son but est d’identifier les meilleurs logiciels d’affaires libres et d’en faire une évaluation sommaire. Pour mieux nous préparer à la recherche des meilleurs candidats, nous avons d’abord fait la revue des différentes méthodologies de sélection de logiciels, autant dans le domaine du propriétaire que du libre. Par la suite, nous avons établi la liste des différents types de logiciels d’affaires, en prenant comme toile de fond les principes de la réingénierie des processus. Finalement, nous avons appliqué une série de cribles dans le but d'identifier une dizaine de logiciels libres matures. De tous les candidats potentiels, trois ont été retenus pour une évaluation ergonomique et fonctionnelle sommaire. Compiere : présenté comme un ERP, Compiere permet d’automatiser les processus d’achat, de vente, de gestion d’inventaire et les opérations comptables. Il est programmé en Java et son installation est facile. L’évaluation ergonomique s’est avérée satisfaisante. L’offre de services professionnels est déjà importante. L’enthousiasme de la communauté semble donc justifié. ERP5 : choisi parmi les finalistes pour son caractère unique. C’est le seul logiciel de gestion de production. Cependant, il s’est avéré impossible à installer. Il fut aussi impossible d’obtenir du support technique. Pour ces raisons, nous ne recommandons pas ce logiciel pour un site pilote. SQL-Ledger : Essentiellement un logiciel de comptabilité, son installation s’est avérée très facile. Ce logiciel est aussi bien supporté par sa communauté. Cependant, le processus d’évaluation a révélé des déficiences ergonomiques importantes. Nous ne pouvons donc recommander ce logiciel. En conclusion, Compiere se démarque clairement parmi les logiciels d’affaires libres. C’est un logiciel mature qui offre à faible coût des fonctions requises par un très grand nombre de PME. Cette étude n’est pas suffisante pour recommander formellement ces logiciels aux entreprises canadiennes. Une étude plus approfondie, tel un projet pilote en entreprise, sera nécessaire. Nous recommandons que Compiere soit choisi pour ces projets pilotes.

MRI Low Signal Prominence at the Anteroinferior Glenohumeral Joint Recess: Frequency, Associated MRI Findings, and Arthroscopic Correlation

Shoulder MRI occasionally shows a low signal prominence at the anteroinferior glenohumeral joint (GHJ) recess resembling thickened capsular tissue which has an uncertain clinical significance.Objectives are to examine the frequency of this finding on MR and if it is visualized on arthroscopy, and to correlate with other common shoulderpathologies seen on MR

La place de l'homéopathie dans les pathologies anxieuses

De nos jours, l anxiété et le stress sont deux pathologies de plus en plus rencontrées dans la population générale. Elles peuvent revêtir de multiples formes cliniques telles que le trouble anxieux généralisé, l attaque de panique ou encore la phobie spécifique. Derrière ces pathologies, se cache un vaste champ thérapeutique. Plus communément, c est le traitement anxiolytique qui prône sur les autres thérapeutiques, et plus précisément l emploi de benzodiazépines. Or, il n est pas sans savoir que ces molécules ne sont pas anodines. De nombreux effets indésirables comme la sédation, la tolérance ou encore la dépendance émergent de l utilisation de ces médicaments. C est pourquoi, il est important que le pharmacien développe ses compétences dans l usage des thérapeutiques alternatives. Parmi celles-ci, il y a l homéopathie. L homéopathie, créée par le médecin Samuel Hahnemann, est une médecine complexe prenant de plus en plus d ampleur auprès des professionnels de santé et du grand public. En s appuyant sur des études cliniques, elle se révèle être une excellente thérapeutique des troubles anxieux.Nowadays anxiety and stress disorders are two pathologies that are found more and more often throughout the general population. They can take multiple clinical forms such as generalized anxiety disorder (GAD), panic disorder or even a specific phobia. Behind these pathologies there is a vast, hidden therapeutic field. The anxiolytic treatment is the most commonly recommended, and more precisely, the use of benzodiazepines. Nevertheless, their molecules are not harmless. Numerous and undesirable effects such as sedation, tolerance and physical dependency can occur after the use of these medicine. That is why, it is important that pharmacists develop their expertise on the use of alternative therapies. Among these therapies is homeopathy. Homeopathy, which was created by the German physician Samuel Hahnemann, is a complex medicine, and the use of it by health professionals and the general public is growing is size. Based on clinical studies, homeopathy has revealed itself as an excellent therapy for anxiety disorders.ANGERS-BU Médecine-Pharmacie (490072105) / SudocSudocFranceF

In vivo methods for imaging blood–brain barrier function and dysfunction

International audienceThe blood–brain barrier (BBB) is the interface between the central nervous system and systemic circulation. It tightly regulates what enters and is removed from the brain parenchyma and is fundamental in maintaining brain homeostasis. Increasingly, the BBB is recognised as having a significant role in numerous neurological disorders, ranging from acute disorders (traumatic brain injury, stroke, seizures) to chronic neurodegeneration (Alzheimer’s disease, vascular dementia, small vessel disease). Numerous approaches have been developed to study the BBB in vitro, in vivo, and ex vivo. The complex multicellular structure and effects of disease are difficult to recreate accurately in vitro, and functional aspects of the BBB cannot be easily studied ex vivo. As such, the value of in vivo methods to study the intact BBB cannot be overstated. This review discusses the structure and function of the BBB and how these are affected in diseases. It then discusses in depth several established and novel methods for imaging the BBB in vivo, with a focus on MRI, nuclear imaging, and high-resolution intravital fluorescence microscopy

Resolving sets for Johnson and Kneser graphs

A set of vertices $S$ in a graph $G$ is a {\em resolving set} for $G$ if, for any two vertices $u,v$, there exists $x\in S$ such that the distances $d(u,x) \neq d(v,x)$. In this paper, we consider the Johnson graphs $J(n,k)$ and Kneser graphs $K(n,k)$, and obtain various constructions of resolving sets for these graphs. As well as general constructions, we show that various interesting combinatorial objects can be used to obtain resolving sets in these graphs, including (for Johnson graphs) projective planes and symmetric designs, as well as (for Kneser graphs) partial geometries, Hadamard matrices, Steiner systems and toroidal grids.Comment: 23 pages, 2 figures, 1 tabl

Subaortic stenosis in the spectrum of atrioventricular septal defects Solutions may be complex and palliative

AbstractFrom July 1982 through September 1994, 19 children had operative treatment of subaortic stenosis associated with an atrioventricular septal defect. Specific diagnosis were septum primum defects in 7, Rastelli type A defects in 6, transitional defects in 4, inlet ventricular septal defect with malattached chordae in 1, and tetralogy of Fallot with Rastelli type C defect in 1. Twenty-seven operations for subaortic stenosis were performed. Surgical treatment of the outlet lesion was performed at initial atrioventricular septal defect repair in 3 children and in the remaining 16 from 1.2 to 13.1 years (mean 4.9 years, median 3.9 years) after repair. Eighteen of the 19 children had fibrous resection and myectomy for relief of obstruction. Seven children had an associated left atrioventricular valve procedure. One child received an apicoaortic conduit. Seven children (36.8%) required 8 reoperations for previously treated subaortic stenosis. Time to the second procedure was 2.8 to 7.4 years (mean 4.9 years). Follow-up is 0.4 to 14.0 years (median 5.6 years). Six-year actuarial freedom from reoperation is 66% ±15%. The angle between the plane of the outlet septum and the plane of the septal crest was measured in 10 normal hearts (86.4 ±13.7) and 10 hearts with atrioventricular septal defects (22.2 ±26.0; p <0.01). The outflow tract can be effectively shortened, widened, and the angle increased toward normal by augmenting the left side of the superior bridging leaflet and performing a fibromyectomy. Conclusion: Standard fibromyectomy for subaortic stenosis in children with atrioventricular septal defects leads to a high rate of reoperation. Leaflet augmentation and fibromyectomy may decrease the likelihood of reoperation. (J THORAC CARDIOVASC SURG 1995;110:1534-42

Noise2Recon: Enabling Joint MRI Reconstruction and Denoising with Semi-Supervised and Self-Supervised Learning

Deep learning (DL) has shown promise for faster, high quality accelerated MRI reconstruction. However, supervised DL methods depend on extensive amounts of fully-sampled (labeled) data and are sensitive to out-of-distribution (OOD) shifts, particularly low signal-to-noise ratio (SNR) acquisitions. To alleviate this challenge, we propose Noise2Recon, a model-agnostic, consistency training method for joint MRI reconstruction and denoising that can use both fully-sampled (labeled) and undersampled (unlabeled) scans in semi-supervised and self-supervised settings. With limited or no labeled training data, Noise2Recon outperforms compressed sensing and deep learning baselines, including supervised networks, augmentation-based training, fine-tuned denoisers, and self-supervised methods, and matches performance of supervised models, which were trained with 14x more fully-sampled scans. Noise2Recon also outperforms all baselines, including state-of-the-art fine-tuning and augmentation techniques, among low-SNR scans and when generalizing to other OOD factors, such as changes in acceleration factors and different datasets. Augmentation extent and loss weighting hyperparameters had negligible impact on Noise2Recon compared to supervised methods, which may indicate increased training stability. Our code is available at https://github.com/ad12/meddlr