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The aim of this article is to upgrade the performance of polypropylene/ethylene propylene rubber (PP/EPR) blends by addition of hydrophobic nanosilica (SiR805) and using “high shear processing technology”. The morphological developments, mechanical and rheological properties of these composites were investigated as a function of processing conditions. High shear processing has proved to be an efficient process to decrease the size of the dispersed phase (EPR) up to 300 nm and to disperse finely nanosilica particles to less than 30 nm especially at 800 min-1. Moreover, the morphology stability of the nanocomposite is ascribed to the formation of a core shell structure (EPR nodules = core; nano-silica = shell) and selective location of nanosilica at the interface. More importantly, this core-shell structure is favoured to enhance the impact strength of the (PP/EPR)/3 wt% SiR805 nanocomposite. In agreement to the obtained morphology, the improvement (about 60 %) of elongation at break attests a good adhesion between phases due to high shear effect as highlighted by viscoelastic properties. Therefore, high shear processing technology has proved to be a relevant method to prepare nanocomposites with high performances without adding any additive and offers new perspectives for recycling and lightening structures.

The residence time distributions (RTD) of a high shear twin screw extruder were measured by an on–line UV fluorescence device. First, by increasing throughput (Q) and screw speed (N), a decrease of the complex viscosity of the studied polypropylene (PP) was observed, revealing chain scissions. It was associated to high viscous dissipation taking place during extrusion, and more particularly under high shear conditions. Then the impact of these experimental conditions on the RTD was carried out. As expected, an increase of usual throughputs and screw speeds decrease mostly the RTD characteristic data. In this study industrial rate have been studied: throughput varied from 1.5 up to 22 kg h-1and screw speed varied from 200 min-1up to 1 200 min-1. However, by increasing the screw speed over usual values (from 500 up to 1 200 min-1), the variation of some experimental RTD characteristics were unexpected. Indeed, the slope of the shape of the experimental RTD function E(t) changed significantly. This phenomenon will be called lag or delay time. This result was only observed at low throughputs and high screw rotation speeds. To finish, a modeling software of twin screw extrusion process was used to compare experimental and calculated results. For usual processing conditions (up to 700 min-1), the simulation predicts nicely the experimental RTDs. However, at high screw speed (N > 800 min-1) and moderate throughput (Q = 4 kg h-1), the simulation fails to predict the RDT delay time. Hence, some side effects apparently occurred during high shear extrusion at low throughputs.

To assess the efficacy and toxicity of pegylated liposomal doxorubicin combined with gemcitabine as first-line chemotherapy in metastatic breast cancer patients in a phase II trial.

La place de l’irradiation axillaire dans la prise en charge du cancer du sein reste très discutée. Alors que la valeur pronostique péjorative d’une atteinte ganglionnaire axillaire a été largement démontrée, le bénéfice d’un traitement axillaire reste plus incertain. Les grands essais cliniques, ayant montré le bénéfice de la radiothérapie postopératoire des tumeurs localement évoluées, ont comporté une irradiation ganglionnaire large, incluant la région axillaire. Cependant, l’étendue variable du curage dans ces études rend l’interprétation du bénéfice de la radiothérapie axillaire difficile. Bien que l’irradiation axillaire postopératoire des patientes, présentant une atteinte ganglionnaire étendue ou un curage insuffisant, demeure consensuelle, le pronostic de ces patientes reste bien souvent lié à l’évolution métastatique de la maladie et une telle stratégie majore la toxicité et les séquelles fonctionnelles potentielles. Des évaluations complémentaires devraient permettre de mieux définir les indications et le bénéfice réel de l’irradiation axillaire.

Les sels de platines sont une classe pharmacologique majeure en oncologie. Ils sont utilisés dans presque tous les types de tumeurs solides. Leur chef de file, le cisplatine, est connu depuis de nombreuses années. Son efficacité et ses toxicités sont bien documentées dans la littérature. Le carboplatine possède un profil de toxicité différent et semble mieux toléré avec un impact potentiel favorable en termes de qualité de vie. Il a été développé dans la majorité des indications du cisplatine. Le but de la présente revue de la littérature est de réaliser un état des lieux le plus exhaustif possible des indications en termes de supériorité d’efficacité ou autre du carboplatine vis-à-vis du cisplatine et inversement. Si pour les tumeurs bronchopulmonaires et germinales, l’efficacité du cisplatine est supérieure, lorsque la chimiothérapie n’est pas prescrite dans un but curatif la meilleure tolérance du carboplatine pourrait être prise en compte dans des études évaluant plus la qualité de vie que la réponse au traitement. Bien sur, il reste au carboplatine les contre-indications de l’utilisation du cisplatine.

Le but de l’étude est de mesurer le niveau d’activité physique des patientes traitées pour un cancer du sein à travers un questionnaire, le Population Physical Activity Questionnaire(POPAQ) et de comparer les résultats obtenus avec deux populations féminines, l’une non pathologique et l’autre présentant une anamnèse de pathologie cardiovasculaire.

Free-radical solution copolymerization of acrylamide (AAm) and of a disubstituted acrylamide derivative, N-acryloylmorpholine (NAM), with N-acryloxysuccinimide (NAS) was investigated with the aim to obtain a copolymer of at least 100,000 g mol⁻¹. Different polymerization conditions likely to increase the molecular weight were studied such as monomer and initiator concentrations, temperature, and nature of the solvent. The molecular weights were determined by SEC using a light-scattering detector. The grafting of end-functionalized polysaccharide chains onto such high molecular weight poly(NAM-co-NAS) was performed and a graft copolymer bearing a high number of saccharidic branches was obtained. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1808–1816, 2003

Bulk polymerization of urethane made from diphenylmethane 4, 4' diisocyanate (MDI) and polyether macro diol was performed from size exclusion chromatography and viscoelastic studies. Coupling the viscoelastic characterization and the kinetic law showed that the viscoelastic behavior of the urethane system is only dependent of the degree of polymerization. The rheological study proved that low physical interactions can be found between the polyurethane chains. Furthermore, the critical molecular weight corresponding to a rheological maximum effect of these interactions was observed close to the value Mc = 2Me, characterizing the onset of the topological entanglement coupling. A qualitative explanation of this singular behavior was attempted from a hydrogen bonding point of view. On the other hand, the linear viscoelastic properties of polyurethane samples of different molecular weights were studied. The main viscoelastic parameters, ηo, $J^0_{\hbox{e}}$ and $G^0_{\hbox{N}}$ were determined. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2395–2406, 1997