Mesure des contraintes résiduelles dans les pièces moulées par injection

Les contraintes résiduelles -- Processus de formation -- Influence des paramètres de mise en forme -- Méthodes de mesure -- Procédure expérimentale -- Matériaux et échantillons -- Appareillage expérimental -- Mesure des contraintes résiduelles -- Influence de la température du monde : comparaison entre les températures basse, nominale et haute -- Influence de la vitesse d'injection : comparaison entre les vitesses basse, nominale et haute -- Influence de la mesure du rayon de courbure sur les contraintes résiduelles

Simulation numérique d'un système antigivre pour ailes d'avions

Code de givrage -- Système antigivre -- Film mince -- Rugosités de surface -- Modèle mathématique -- Écoulement externe -- Eau de ruissellement -- Région solide -- Région d'écoulement interne -- Méthodes numériques -- Écoulement potentiel et trajectoires -- Couche limite et région d'eau de ruissellement -- Région solide -- Coefficient de convection interne -- Validations préliminaires -- Film liquide -- Couche limite sur plaque plane -- Cylindre -- Résultats et discussion -- Système antigivre électrique -- Simulation d'un système antigivre à air chaud

Predictive Factors of Poor Prognosis After Surgical Management of Traumatic Acute Subdural Hematomas: A Single-Center Series

BACKGROUND: Traumatic acute subdural hematomas (ASDHs) showed the highest mortality of intracranial hematomas. The aim of the current study was to identify predictive factors of poor prognosis among patients who were operated on. METHODS: This is a single-center retrospective cohort study of 82 patients who underwent surgical evacuation of a traumatic ASDH between January 2009 and December 2016. The epidemiologic, clinical, radiologic, and surgical features were recorded. Postoperative outcome were assessed by the Glasgow Outcome Scale (GOS) score at 6 months. Univariate and multivariate analysis and a classification and regression tree (CART) were performed. RESULTS: At 6 months, 76% of patients achieved an unfavorable outcome (GOS score 1-3). The context of polytrauma (P = 0.03) and ASDH thickness ≥20 mm (P = 0.02) were significantly associated with poor outcome in the multivariate analysis. The CART algorithm isolated 3 subgroups of patients with an unfavorable prognosis: polytrauma (91%), isolated head injury (HI) featuring an ASDH thickness ≥20 mm (89%), or isolated HI featuring a thickness <20 mm in a patient older than 54 years (71%). Isolated patients with HI younger than 54 years harboring an ASDH <20 mm thick had the most promising results, with 53% with a GOS score of 4 or 5. CONCLUSIONS: The context of polytrauma, ASDH thickness, and age were major predictive factors of poor prognosis in patients with surgically evacuated traumatic ASDH. The CART algorithm using these features isolated subgroups with decreasingly unfavorable outcome, providing a relevant statistical tool to apply to future studies of traumatic ASDH

Spheno-Orbital Meningiomas

Spheno-orbital meningiomas are mainly defined as primary en plaque tumors of the lesser and greater sphenoid wings, invading the underlying bone and adjacent anatomical structures. The patients, mostly women in their fifties, generally present with a progressive, unilateral, and nonpulsatile proptosis, often associated with cosmetic deformity and optic nerve damage. Surgical resection is currently the gold standard of treatment in case of optic neuropathy, significant symptoms, or radiological progression. The surgical strategy should take into account the morphology of the tumor, its epicenter at the level of the sphenoid wing, and the invasion of adjacent anatomical structures. Surgery stabilizes or improves visual function and oculomotricity in most cases but it is rare that the proptosis recovers completely. Gross total resection is hard to achieve considering the complex anatomy of the spheno-orbital region and the risk of inducing cranial nerve deficits. Rare cases of WHO grade II or III meningiomas warrant adjuvant radiotherapy. Tumor residues after subtotal resections of WHO grade I meningiomas are first radiologically monitored and then treated by stereotactic radiosurgery in case of progression

Ectopic expression of PtaRHE1, encoding a poplar RING-H2 protein with E3 ligase activity, alters plant development and induces defence-related responses

RING (really interesting new gene)-H2 domain-containing proteins are widely represented in plants and play important roles in the regulation of many developmental processes as well as in plant–environment interactions. In the present report, experiments were performed to unravel the role of the poplar gene PtaRHE1, coding for a RING-H2 protein. In vitro ubiquitination assays indicate a functional E3 ligase activity for PtaRHE1 with the specific E2 ubiquitin-conjugating enzyme UbcH5a. The overexpression of PtaRHE1 in tobacco resulted in a pleiotropic phenotype characterized by a curling of the leaves, the formation of necrotic lesions on leaf blades, growth retardation, and a delay in floral transition. The plant gene expression response to PtaRHE1 overexpression provided evidence for the up-regulation of defence- and/or programmed cell death-related genes. Moreover, genes coding for WRKY transcription factors as well as for mitogen-activated protein kinases, such as wound-induced protein kinase (WIPK), were also found to be induced in the transgenic lines as compared with the wild type. In addition, histochemical β-glucuronidase staining showed that the PtaRHE1 promoter is induced by plant pathogens and by elicitors such as salicylic acid and cellulase. Taken together, these results suggest that the E3 ligase PtaRHE1 plays a role in the ubiquitination-mediated regulation of defence response, possibly by acting upstream of WIPK and/or in the activation of WRKY factors

The Surgeon in Action: Representations of Neurosurgery in Movies from the Frères Lumière to Today

In this review, we examine the portrayal of neurosurgery and neurosurgeons in 61 movies produced from the beginnings of cinema from the Lumière brothers (1895) to 2017, across 4 continents and covering 10 cinematic genres. We find that these movies tend to shape most beliefs and stereotypes about neurosurgery. However, we notice that there is a trend to describe neurosurgery and neurosurgical disorders with more accuracy as we progress in time. Although it is not for the medical profession to dictate or censor fictional content, a keen eye on these depictions will help us to understand, and perhaps combat, some of the stereotypes and myths that continue to surround neurosurgery in the twenty-first century

Functional analysis of a cinnamyl alcohol dehydrogenase involved in lignin biosynthesis in wheat

Cinnamyl alcohol dehydrogenase (CAD) catalyses the final step in the biosynthesis of monolignols. In the present study, a cDNA encoding a CAD was isolated from wheat, designated as TaCAD1. A genome-wide data mining in the wheat EST database revealed another 10 CAD-like homologues, namely TaCAD2 to TaCAD11. A phylogenetic analysis showed that TaCAD1 belonged to the bona fide CAD group involved in lignin synthesis. Two other putative CADs from the wheat genome (TaCAD2 and TaCAD4) also belonged to this group and were very close to TaCAD1, but lacked C-terminal domain, suggesting that they are pseudogenes. DNA gel blot analysis for the wheat genome showed two to three copies of CAD related to TaCAD1, but RNA gel blot analysis revealed only single band for TaCAD1, which was highly expressed in stem, with quite low expression in leaf and undetectable expression in root. The predicted three-dimension structure of TaCAD1 resembled that of AtCAD5, but two amino acid substitutions were identified in the substrate binding region. Recombinant TaCAD1 protein used coniferyl aldehyde as the most favoured substrate, also showed high efficiencies toward sinapyl and p-coumaryl aldehydes. TaCAD1 was an enzyme being pH-dependent and temperature-sensitive, and showing a typical random catalysing mechanism. At the milky stage of wheat, TaCAD1 mRNA abundance, protein level and enzyme activity in stem tissues were higher in a lodging-resistant cultivar (H4546) than in lodging-sensitive cultivar (C6001). These properties were correlated to the lignin contents and lodging indices of the two cultivars. These data suggest that TaCAD1 is the predominant CAD in wheat stem for lignin biosynthesis and is critical for lodging resistance

Over-expression of a putative poplar glycosyltransferase gene, PtGT1, in tobacco increases lignin content and causes early flowering

Family 1 glycosyltransferases catalyse the glycosylation of small molecules and play an important role in maintaining cell homeostasis and regulating plant growth and development. In this study, a putative glycosyltransferase gene of family 1, PtGT1, was cloned from poplar (Populus tomentosa Carr.). Sequence analysis showed that this gene encodes a protein of 481 amino acid residues with a conserved PSPG box at its C-terminal, suggesting that it is active in the glycosylation of plant secondary products. The PtGT1 gene was expressed in poplar stems and leaves, with a particularly high expression level in elongating stems. Transgenic tobacco plants ectopically over-expressing PtGT1 were obtained and phenotypes were analysed. Wiesner and Mäule staining showed that stem xylem of transgenic tobacco plants stained more strongly than controls. Measurement of the Klason lignins showed much higher lignin content in the transgenic lines than in control plants. Furthermore, the ectopic over-expression of PtGT1 in tobacco resulted in an early flowering phenotype. These findings offer a possible starting point towards better understanding of the function of poplar PtGT1, and provide a novel strategy for lignin engineering and flowering control in plants through the genetic manipulation of a poplar glycosyltransferase gene