A new fast method for ceramic foam impregnation: Application to the CCVD synthesis of carbon nanotubes

A new process that allows preparing, in a single step, good washcoats of catalytic materials for the catalytic chemical vapour deposition (CCVD) synthesis of carbon nanotubes (CNTs) in reticulated ceramic foams is reported. It is shown that the washcoats, obtained by impregnation using viscous slurries made of finely divided powders dispersed in different media, cover the total surface of foams with good adhesions. The catalytic activity with regards to the CNT synthesis is finally verified, showing that our new fast impregnation process makes possible to get materials with final architectures suitable for heterogeneous catalysis applications

Surgical technic of laryngoplasty in standing horse

Une ventriculo-cordectomie uni ou bilatérale par laser, suivie d’une laryngoplastie, a été effectuée sous contrôle endoscopique chez des chevaux tranquillisés avec désensibilisation du site chirurgical par une anesthésie locale. La laryngoplastie a été bien tolérée sans aucune hyperabduction du carti-lage aryténoïde paralysé. Les complications telles que toux, dysphagie et les complications de plaie sont survenues dans un nombre minimal de chevaux. L’analyse des résultats à long terme a montré une résolution des signes cliniques respiratoires chez environ 95 % des chevaux. La laryngoplastie effectuée chez le cheval debout permet d’éviter les risques associés à l’anesthésie générale et au réveil et donne des résultats au moins équivalents à à ceux de la laryngoplastie réalisée sous anesthésie générale. L’avantage principal de cette technique est de permettre un ajustement peropératoire précis du degré d’abduction du cartilage aryténoïde.A unilateral or bilateral laser ventriculo-cordectomy followed by a laryngoplasty were performed under endoscopic guidance in the standing sedated horse, and the surgical site was desensitized with local anesthetic solution. In our experience, laryngoplasty was completed in all horses and was well tolerated. No hyperabduction of the affected arytenoid cartilage was observed. Complications such as coughing, dysphagia, and wound complications were encoutered in a minority of cases. Respiratory function improved satisfactory in 95% of horses at late follow-up. Laryngoplasty performed in the standing horse avoids risk associated with general anesthesia and recovery and its results were compar¬able to the procedure performed under general anaesthesia. The principal advantage of this tech¬nique is to allow accurate intraoperative adjustment of the degree of arytenoid cartilage abduction

Physiological surgical treatment of laryngeal hemiplegia in horses

Au cours des dernières années le traitement chirurgical de l’hémiplégie laryngée a considérablement évolué. Bien que la laryngoplastie reste le traitement de référence, la technique de greffe de nerf cervical représente le seul moyen de rétablir physiologiquement la fonction laryngée avec un risque de complications inférieur. Des critères objectifs de sélection puis de suivi des candidats permettent d’offrir un bon pronostic aux chevaux de sport ou de course, bien que plus de recul soit nécessaire sur ces derniers. L’endoscopie au repos et à l’exercice, l’échographie laryngée, et le test d’électro-stimulation du nerf greffé apportent des informations essentielles sur le grade du cornage, sur le degré d’amyotrophie du muscle cricoaryténoïdien dorsal (CAD) ainsi que le suivi de sa réinnervation et de sa récupération fonctionnelle. Cette technique chirurgicale a déjà montré son efficacité dans des grades précoces d’hémiplégie laryngée et lorsque le temps de réhabilitation est compatible avec le programme sportif des chevaux. Ce traitement physiologique de l’hémiplégie laryngée pourrait être élargi dans l’avenir à des grades plus avancés en l’associant avec un neurostimulateur relié à une électrode fixée sur le nerf greffé dans le but d’améliorer la réhabilitation du muscle CAD et la fonction laryngée à l’exercice.Presently, C1-C2 cervical nerve graft represents the only mean of restoring the physiological laryngeal function, with a low risk of complications, in horses with laryngeal hemiplegia. Selection criteria and follow-up of the candidates make possible for operated horses a return to their initial activity. The endoscopy at rest and at exercise, laryngeal echography and electrostimulation of the grafted nerve give essential information on the severity of the laryngeal hemiplegia, the degree of amyotrophy of the dorsal crico-arytenoideus muscle (CAD), its reinnervation and its functional recovery. This surgical technique already showed its effectiveness in early stages of laryngeal hemiplegia and when the time of rehabilitation is suitable with the activity of the horses. This physiological treatment of laryngeal hemiplegia could be extended to more severely affected horses, in combination with an electrostimulator using an electrode implanted into the grafted C1 nerve. This may improve the rehabilitation of the CAD muscle as well as laryngeal function at exercise

Study of the Effect of Siliceous Species in the Formation of a Geopolymer Binder: Understanding the Reaction Mechanisms among the Binder, Wood, and Earth Brick.

International audienceIn building construction, geopolymer binder or mortar can interact with the structural materials and thus modify the binder formation mechanisms. In a geopolymer binder, the availability and amount of siliceous species is a preponderant parameter influencing the nature of networks formed after consolidation. In this study, the interactions between the binder and structural materials (wood and earth bricks) were investigated by 29Si magic angle spinning nuclear magnetic resonance (MAS NMR) and Fourier transform infrared spectroscopy (FTIR) during and after the consolidation. Then, the effect of the amount and nature of the siliceous species available in the reaction medium were analyzed. According to the siliceous species available, it is possible to form different types of materials (hardening or sedimented materials). By corroborating these results with MAS NMR and FTIR analyses, a formation scheme of the binder in contact with the materials was proposed

aHIF but not HIF-1α transcript is a poor prognostic marker in human breast cancer

BACKGROUND: Hypoxia-inducible factor-1α (HIF-1α) is part of a transcriptional factor that regulates genes involved in metabolic and vascular adaptation of tumours to oxygen restriction. A splicing variant lacking exon 14 (sHIF-1α) encodes a truncated protein that competes with the normal HIF-1α protein, decreasing its activity. A natural antisense transcript (aHIF) complementary to the 3'-untranslated region of HIF-1α mRNA was described recently. METHODS: With a semiquantitative multiplex reverse transcriptase–PCR (RT–PCR) assay, we assessed transcript concentrations of HIF-1α, sHIF-1α and aHIF in 110 patients with invasive breast carcinoma. RESULTS: We found a strong positive association between HIF-1α and sHIF-1α, sHIF-1α and aHIF, and an inverse correlation between HIF-1α /sHIF-1α and aHIF. aHIF transcript expression was associated with poor disease-free survival in univariate (P = 0.0038) and multivariate (P = 0.0016) analyses in this series of high-risk primary breast carcinomas. CONCLUSION: In our series of breast cancer patients, aHIF, and not HIF-1α transcript, is a marker of poor prognosis

CaCu3Ti4O12 ceramics from co-precipitation method: Dielectric properties of pellets and thick films

Dielectric properties of CaCu3Ti4O12 (CCTO)-based ceramics and thick films (e ∼50m) prepared from powders synthesized by a soft chemistry method (co-precipitation) are presented and discussed. The characteristics of pellets and thick films are compared. The pellets exhibit high values of the dielectric permittivity (εr ∼1.4×105) and relatively small dielectric losses (tan δ ∼0.16) at 1 kHz and room temperature. These properties are independent of the nature of the metallization of the electrodes. In addition, the dielectric permittivity decreases when the diameter of the electrodes of the pellets increases, while the losses remain constant. This result, which is strongly related to the nature of the dielectric material in between the electrodes, constitutes a strong indication that the high dielectric permittivity values observed in this material are not related to an interfacial (electrode material) related mechanism but is an internal barrier layer capacitor (IBLC) type. Very high values of the dielectric permittivity of CCTO thick films are measured (εr ∼5×104). The differences in dielectric permittivity between thick films and dense pellets may be attributed to the difference in grain size due to different CuO contents, and to the different reactivity of the materials

Biomimetic apatite sintered at very low temperature by spark plasma sintering: Physico-chemistry and microstructure aspects

Nanocrystalline apatites analogous to bone mineral are very promising materials for the preparation of highly bioactive ceramics due to their unique intrinsic physico-chemical characteristics. Their surface reactivity is indeed linked to the presence of a metastable hydrated layer on the surface of the nanocrystals. Yet the sintering of such apatites by conventional techniques, at high temperature, strongly alters their physico-chemical characteristics and biological properties, which points out the need for "softer" sintering processes limiting such alterations. In the present work a non-conventional technique, spark plasma sintering, was used to consolidate such nanocrystalline apatites at non-conventional, very low temperatures (T° < 300 °C) so as to preserve the surface hydrated layer present on the nanocrystals. The bioceramics obtained were then thoroughly characterized by way of complementary techniques. In particular, microstructural, nanostructural and other major physico-chemical features were investigated and commented on. This work adds to the current international concern aiming at improving the capacities of present bioceramics, in view of elaborating a new generation of resorbable and highly bioactive ceramics for bone tissue engineering

Synthesis and biological evaluation of diversely substituted indolin-2-ones

International audienceThe synthesis of indolin-2-one derivatives substituted in the 3-position by an aminomethylene group bearing either an ornithine or a lysine residue is described. The inhibitory activities of these compounds toward a panel of eight kinases were examined. Furthermore, the antibacterial activities of the prepared compounds were tested against two Gram-positive bacteria Bacillus cereus and Streptomyces chartreusis, a Gram-negative bacterium Escherichia coli and a yeast Candida albicans