82 research outputs found

    Viral Encephalopathy and Retinopathy (VER) in Mediterranean wild and farmed fish species : the experience of the ‘Istituto Zooprofilattico Sperimentale’ in Sicily

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    Betanodavirus infection is widespread in a broad spectrum of fish species worldwide. In Italy, it is responsible for outbreaks of Viral Encephalo-Retinopathy (VER) that causes mortality and economic losses in sea fish farming. The infection is also widespread in the wild and not only in managed systems, where there are generally no observed clinical manifestations.peer-reviewe

    Dickkopf-3 upregulates VEGF in cultured human endothelial cells by activating activin receptor-like kinase 1 (ALK1) pathway

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    Dkk-3 is a member of the dickkopf protein family of secreted inhibitors of the Wnt pathway, which has been shown to enhance angiogenesis. The mechanism underlying this effect is currently unknown. Here, we used cultured HUVECs to study the involvement of the TGF-β and VEGF on the angiogenic effect of Dkk-3. Addition of hrDkk-3 peptide (1 or 10 ng/ml) to HUVECs for 6 or 12 h enhanced the intracellular and extracellular VEGF protein levels, as assessed by RTPCR, immunoblotting, immunocytochemistry and ELISA. The increase in the extracellular VEGF levels was associated to the VEGFR2 activation. Pharmacological blockade of VEGFR2 abrogated Dkk-3-induced endothelial cell tubes formation, indicating that VEGF is a molecular player of the angiogenic effects of Dkk-3. Moreover, Dkk-3 enhanced Smad1/5/8 phosphorylation and recruited Smad4 to the VEGF gene promoter, suggesting that Dkk-3 activated ALK1 receptor leading to a transcriptional activation of VEGF. This mechanism was instrumental to the increased VEGF expression and endothelial cell tubes formation mediated by Dkk-3, because both effects were abolished by siRNA-mediated ALK1 knockdown. In summary, we have found that Dkk-3 activates ALK1 to stimulate VEGF production and induce angiogenesis in HUVECs

    OBTAINING MESENCHYMAL STEM CELLS FROM ADIPOSE TISSUE OR MURIN ORIGIN: EXPERIMENTAL STUDY.

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    The aim of this study was to isolate and characterize rat adipose Derived Mesenchymal Stem Cells (AD-MSCs) in order to evaluate their proliferative potential and their ability to different cell types. AD-MSCs and Derived Mesenchymal Stem Cells (BM-MSCs) have the same characteristic in terms of plasticity. The advantage of adipose tissue is that it is an easier accessible source and it offers a large amount of MSCs by less invasive surgical tecniques. MSCs were obtained from subcutaneous adipose tissue of Wistar rats. first of all microbiological controls were made to exclude the presence of bacteria of fungi in then tissue. Adipose tissue was mechanically and enzimatically fragmented and stromal cell fraction was seeded in adherent culture flasks in DMEM 20% FBS. After 48 h the medium was replaced. Cells were characterized by evaluating:1)their ability tho adhere to the plastic; 2) the clonogenic potential by Colony Forming Unit (CFU) assay, 3) their ability to differentiate in 3 mesodermal lineages (adipocytes, osteocytes and chondrocytes). AD-MSCs are able to differentiate in adipocytes, osteocytes and chondrocytes as confirmed by oil red'O staining, von Kossa staining and histological analuysis respectively. This first characterization is essential for the second part of our study in which we are planning to use AD-MSCs in vivo to restore renal function after an induced ischemic damage in experimental animals

    Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

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    The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe

    Coexistence of plasmonic and magnetic properties in Au89Fe11 nanoalloys

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    We describe an environmentally friendly, top-down approach to the synthesis of Au89Fe11 nanoparticles (NPs). The plasmonic response of the gold moiety and the magnetism of the iron moiety coexist in the Au89Fe11 nanoalloy with strong modification compared to single element NPs, revealing a non-linear surface plasmon resonance dependence on the iron fraction and a transition from paramagnetic to a spin-glass state at low temperature. These nanoalloys are accessible to conjugation with thiolated molecules and they are promising contrast agents for magnetic resonance imaging

    Structural behaviour of hybrid glass beams with T cross-sections

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    An experimental investigation regarding the flexural and the shear behaviour of glass beams with length 900, 1300, 1700 mm and T cross-section is presented and discussed. T cross-sections were obtained by assembling glass web and glass flange. Some specimens were also reinforced internally in the web with steel plates of thickness 6 mm and depth 25 and 50 mm placed at the bottom portion of the beams for the entire length of the beams themselves. Three specimens for each investigated series were tested in flexure focusing on the flexural and shear response through the determination of the load-deflection curves and the crack patterns at rupture identifying the effects of steel plates. The shear span to depth ratios a/d were 2, 3 and 4, respectively. A simple model is also presented for a preliminary design of composite glass beams able to predict the ultimate load including limit states due to glass cracking, flexural failure with glass crushing or plates yielding, shear compression and diagonal tension failure. The resistance is obtained from equilibrium conditions of a portion of beam enclosed between the support and shear span, taking also into account the presence of steel plates. The model is able to reproduce experimental results to the varying of the geometrical characteristics of beam, of the reinforcement area and on the type of reinforcement

    Structural Behavior of Telescopic Steel Pipe for a Full-Scale 60 kW Wind Turbine Tower

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    A simple analytical model, including local effects due to buckling and shear to moment interaction, was developed to pre-dict the load-carrying capacity of CHS tubes under flexure and shear. A finite-element analysis with ABAQUS Code was also conducted for validation of the proposed model. By properly modeling the imperfection effects due to the ovalization of steel tube, a good correlation of the structural response and failure mode was also achieved, and a good correlation with the analytical model was also achieved. Numerical and analytical results were compared with experimental results recently obtained by the author with good agreement. Experimental tests refer to full-scale static test to failure were conducted on 6 m length of steel pipe constituting a segment of a telescopic wind tower with a 60-kW wind turbine. The diameter of the circular cross-section of steel pipes was 900 mm and the nominal thickness 10 mm. Steel grade was S355 J2, according to Eurocode 3. Although local buckling caused slight strength degradation, the reduction due to shear to moment interaction was very significant, while the recorded response showed a good amount of post-buckling ductility although the ovalization of cross-sections
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