Ni-Mn-Ga films in the austenite and the martensite structures at room temperature: Uniaxial texturation and epitaxial growth

Ni-Mn-Ga films in the austenite and the martensite structures at room temperature have been obtained using the DC magnetron sputtering technique. Two elaboration processes were studied. A first batch of samples was deposited using a resist sacrificial layer in order to release the film from the substrate before vacuum annealing. This process leads to polycrystalline films with a strong (022) fiber texture. The martensitic phase transformation of such polycrystalline freestanding films has been studied by optical and scanning electron microscopy. A second batch of samples was grown epitaxially on (100)MgO substrates using different deposition temperatures. The texture has been analyzed with four-circle X-ray diffraction. Epitaxial films crystallized both in the austenite and the martensite structures at room temperature have been studied

Effect of side wind on a simplified car model: Experimental and numerical analysis

International audienceA prior analysis of the effect of steady cross wind on full size cars or models must be conducted when dealing with transient cross wind gusts effects on automobiles. The experimental and numerical tests presented in this paper are performed on the Willy square-back test model. This model is realistic compared to a van-type vehicle; its plane under-body surface is parallel to the ground and separations are limited to the base for moderated yaw angles. Experiments were carried out in the semi-open test section at the Conservatoire National des Arts et Métiers (CNAM) and computations were performed at the Ecole Centrale de Nantes (ECN). The ISIS-CFD flow solver, developed by the CFD Department of the Fluid Mechanics Laboratory of ECN, used the incompressible unsteady Reynolds-Averaged Navier-Stokes equations. In this paper, the results of experiments obtained at a Reynolds number of 0.9 106 are compared with numerical data at the same Reynolds number for steady flows. In both the experiments and numerical results, the yaw angle varies from 0° to 30°. The comparison between experimental and numerical results obtained for aerodynamic forces, wall pressures and total pressure maps shows that the unsteady ISIS-CFD solver correctly reflects the physics of steady three-dimensional separated flows around bluff bodies. This encouraging result allows us to move to a second step dealing with the analysis of unsteady separated flows around the Willy model

Three-dimensional separated flows past ground vehicles

The separated flow past a thick body is calculated using a theoretical model based on a discrete wake-vortex representation. Rehbach's unsteady inviscid scheme (1977) was used in the three-dimensional analysis. The obstacle is represented by singularities, and the wake is modeled by vortex particles emitted at the separation line. Calculated results for an axisymmetric body are compared with flow visualization results

Epithelial cell migration on laminins

At the epidermal-dermal junction of the skin, the basal keratinocytes are stably anchored to the underlying basement membrane by specific anchoring structures, the hemidesmosomes. For tissue remodelling, like during wound healing or the cycling growth of the hair follicle, epithelial cell migration occurs and the epithelial cells are forced to reorganize their anchoring structures in order to respond to the new environment. Here, we report that components of the hemidesmosomes, in particular collagen XVII and the tetraspanin CD151, are involved in the regulation of keratinocyte migration in cooperation with the laminin-binding integrins. We observe that collagen XVII-deficient cells are more motile than normal keratinocytes (Tasanen et al., 2004). The tetraspanin CD151 is known to form stable complexes with laminin-binding integrins. In the epidermis, CD151 is associated with alpha3beta1 integrins at cell-cell contacts and with alpha6beta4 integrins in hemidesmosomes. We used a monoclonal antibody against CD151, TS151r, the epitope of which overlaps with the tetraspanin integrin-binding site, to investigate the role of CD151 in the migration of epithelial cells. Under standard culture conditions, the migratory capacity of epithelial HaCaT cells on laminins is low compared to that of Wi26 fibroblasts, apparently due to the production of endogenous laminin 5. However, HaCaT cells treated with TS151r respond to laminin 1 by an enhanced migration. This event is associated with a disruption of cell-cell contacts and a redistribution of beta1 and beta4 integrins. In the hair follicle, free CD151 is present in cell-cell contacts in the epithelial sheet lining the hair bulb, which is considered to contain migrating cells. Together, these results strongly suggest that integrin-bound CD151 inhibits cell migration and that dissociation of the CD151-integrin complex permits cell migration. In contact with the extracellular matrix, the cells capture information through their integrin membrane receptors, which further transduce the signals to the actin cytoskeleton. Two different laminin isoforms, laminin 1 and 5, activate alpha6beta1 and alpha3beta1 integrins, respectively, in fibroblasts and epithelial cells. Upon adhesion, these cells develop laminin-isoform specific morphology and cell-matrix adhesions, which influence the migration pattern of the cells. On laminin 5, the cells develop lamellipodia and very small vinculin patches and migrate in a polarized manner, while on laminin 1, the same cells form filopodia-like structures and thick vinculin aggregates and migrate in an uncoordinated manner, as shown by immunofluorescence staining and time-lapse videomicroscopy, respectively. In HaCaT epithelial cells, these differences can be explained by the activation of different Rho GTPases as shown by pull-down assays of activated Rho GTPases. Upon adhesion on laminin 1, Cdc42 is primarily activated and in the absence of Cdc42 the cells are not able to spread correctly and to develop strong focal adhesions. In contrast, laminin 5 is an activator of Rac1 and a down-regulator of RhoA. In a complementary approach, RhoA and Rac1 were down-regulated in epithelial cells using siRNA. RhoA-deficient HaCaT cells are flat and present small focal complexes, even when plated on laminin 1, while Rac1-deficient HaCaT cells have numerous and large focal adhesions on laminin 1 and laminin 5. An enhanced migration on laminin 1 is obtained when RhoA (to a smaller extent Cdc42) is down-regulated, leading to the development of lamellipodia and tiny focal adhesions. These results show that laminins differentially regulate epithelial cell migration by transducing defined signals via specific membrane receptors. These signals induce the activation of the small Rho GTPases, which participate in the formation of cell morphology and behavior

SÍNDROME DE DOWN: A NARRATIVA MIDIÁTICA EM DIÁLOGO COM O DISCURSO DE SUPERAÇÃO

Em uma sociedade voltada para a lógica produtivista, qual o discurso utilizado para relatar as vidas de pessoas com Síndrome de Down? Para produzir sua aceitação, as mídias forjam um discurso de superação das diferenças que lhes são próprias. O presente trabalho analisou uma série de reportagens sobre síndrome de Down intitulada “Qual é a diferença?”, em um programa de TV, veiculado aos domingos, em horário nobre, a fim de propor uma reflexão sobre a abordagem das mídias em relação a diferença

Fabrication and characterization of a Ni-Mn-Ga uniaxially textured freestanding film deposited by DC magnetron sputtering

Homogeneous freestanding films have been obtained by the direct current (DC) magnetron sputtering technique using a sacrificial layer. After annealing, the films are crystallized with a strong out-of-plane texture along the (022) direction. The stoichiometry of the annealed films is close to the target composition and leads to a martensitic transformation around 255K. The annealed films demonstrate ferromagnetic behavior with a Curie temperature of about 362K. The magnetization process has been studied on the both states and during the martensitic transition. The saturation magnetizations have been determined by fitting the experimental data with a saturation approach law in the range 1-5T. Results show the saturation magnetization of the martensite is around 10% higher than that of the austenite. A model based on intrinsic magnetic properties of each state allowing the description of the magnetization M=f (H, T) of such polycrystalline films during the martensitic transformation is presented. The mass fraction of martensite inside the austenite phase can be determined using this model. The shape memory effect is analyzed both by scanning electron microscopy and by optical microscopy with in-situ measurement of the resistance temperature dependence

Elevated Expression of Stromal Palladin Predicts Poor Clinical Outcome in Renal Cell Carcinoma

The role that stromal renal cell carcinoma (RCC) plays in support of tumor progression is unclear. Here we sought to determine the predictive value on patient survival of several markers of stromal activation and the feasibility of a fibroblast-derived extracellular matrix (ECM) based three-dimensional (3D) culture stemming from clinical specimens to recapitulate stromal behavior in vitro. The clinical relevance of selected stromal markers was assessed using a well annotated tumor microarray where stromal-marker levels of expression were evaluated and compared to patient outcomes. Also, an in vitro 3D system derived from fibroblasts harvested from patient matched normal kidney, primary RCC and metastatic tumors was employed to evaluate levels and localizations of known stromal markers such as the actin binding proteins palladin, alpha-smooth muscle actin (α-SMA), fibronectin and its spliced form EDA. Results suggested that RCCs exhibiting high levels of stromal palladin correlate with a poor prognosis, as demonstrated by overall survival time. Conversely, cases of RCCs where stroma presents low levels of palladin expression indicate increased survival times and, hence, better outcomes. Fibroblast-derived 3D cultures, which facilitate the categorization of stromal RCCs into discrete progressive stromal stages, also show increased levels of expression and stress fiber localization of α-SMA and palladin, as well as topographical organization of fibronectin and its splice variant EDA. These observations are concordant with expression levels of these markers in vivo. The study proposes that palladin constitutes a useful marker of poor prognosis in non-metastatic RCCs, while in vitro 3D cultures accurately represent the specific patient's tumor-associated stromal compartment. Our observations support the belief that stromal palladin assessments have clinical relevance thus validating the use of these 3D cultures to study both progressive RCC-associated stroma and stroma-dependent mechanisms affecting tumorigenesis. The clinical value of assessing RCC stromal activation merits further study

Lack of CD151/integrin alpha 3 beta 1 complex is predictive of poor outcome in node-negative lobular breast carcinoma: opposing roles of CD151 in invasive lobular and ductal breast cancers

background: The proposed involvement of CD151 in breast cancer (BCa) progression is based on findings from studies in invasive ductal carcinoma (IDC). The IDC and invasive lobular carcinoma (ILC) represent distinct disease entities. Here we evaluated clinical significance of CD151 alone and in association with integrin α3β1 in patients with ILC in context of the data of our recent IDC study. methods: Expression of CD151 and/or integrin α3β1 was evaluated in ILC samples (N=117) using immunohistochemistry. The findings were analysed in relation to our results from an IDC cohort (N=182) demonstrating a prognostic value of an expression of CD151/integrin α3β1 complex in patients with HER2-negative tumours. results: Unlike in the IDCs, neither CD151 nor CD151/α3β1 complex showed any correlation with any of the ILC characteristics. Lack of both CD151 and α3β1 was significantly correlated with poor survival (P=0.034) in lymph node-negative ILC N(−) cases. The CD151−/α3β1− patients had 3.12-fold higher risk of death from BCa in comparison with the rest of the ILC N(−) patients. conclusions: Biological role of CD151/α3β1 varies between ILC and IDC. Assessment of CD151/α3β1 might help to identify ILC N(−) patients with increased risk of distant metastases

Simple scoring system to predict in-hospital mortality after surgery for infective endocarditis

BACKGROUND: Aspecific scoring systems are used to predict the risk of death postsurgery in patients with infective endocarditis (IE). The purpose of the present study was both to analyze the risk factors for in-hospital death, which complicates surgery for IE, and to create a mortality risk score based on the results of this analysis. METHODS AND RESULTS: Outcomes of 361 consecutive patients (mean age, 59.1\ub115.4 years) who had undergone surgery for IE in 8 European centers of cardiac surgery were recorded prospectively, and a risk factor analysis (multivariable logistic regression) for in-hospital death was performed. The discriminatory power of a new predictive scoring system was assessed with the receiver operating characteristic curve analysis. Score validation procedures were carried out. Fifty-six (15.5%) patients died postsurgery. BMI >27 kg/m2 (odds ratio [OR], 1.79; P=0.049), estimated glomerular filtration rate 55 mm Hg (OR, 1.78; P=0.032), and critical state (OR, 2.37; P=0.017) were independent predictors of in-hospital death. A scoring system was devised to predict in-hospital death postsurgery for IE (area under the receiver operating characteristic curve, 0.780; 95% CI, 0.734-0.822). The score performed better than 5 of 6 scoring systems for in-hospital death after cardiac surgery that were considered. CONCLUSIONS: A simple scoring system based on risk factors for in-hospital death was specifically created to predict mortality risk postsurgery in patients with IE