Effective properties evaluation for smart composite materials

The purpose of this article is to present a method which consists in the development of unit cell numerical models for smart composite materials with piezoelectric fibers made of PZT embedded in a non-piezoelectric matrix (epoxy resin). This method evaluates a globally homogeneous medium equivalent to the original composite, using a representative volume element (RVE). The suitable boundary conditions allow the simulation of all modes of the overall deformation arising from any arbitrary combination of mechanical and electrical loading. In the first instance, the unit cell is applied to predict the effective material coefficients of the transversely isotropic piezoelectric composite with circular cross section fibers. The numerical results are compared to other methods reported in the literature and also to results previously published, in order to evaluate the method proposal. In the second step, the method is applied to calculate the equivalent properties for smart composite materials with square cross section fibers. Results of comparison between different combinations of circular and square fiber geometries, observing the influence of the boundary conditions and arrangements are presented

Prognostic value of replication errors on chromosomes 2p and 3p in non-small-cell lung cancer

As chromosomes 2p and 3p are frequent targets for genomic instability in lung cancer, we have addressed whether alterations of simple (CA)n DNA repeats occur in non-small-cell lung cancer (NSCLC) at early stages. We have analysed by polymerase chain reaction (PCR) assay replication errors (RER) and loss of heterozygosity (LOH) at microsatellites mapped on chromosomes 2p and 3p in 64 paired tumour-normal DNA samples from consecutively resected stage I, II or IIIA NSCLC. DNA samples were also examined for K-ras and p53 gene mutations by PCR-single-stranded conformational polymorphism (PCR-SSCP) analysis and cyclic sequencing, as well as their relationship with clinical outcome. Forty-two of the 64 (66%) NSCLC patients showed RER at single or multiple loci. LOH was detected in 23 tumours (36%). Among patients with stage I disease, the 5-year survival rate was 80% in those whose tumours had no evidence of RER and 26% in those with RER (P = 0.005). No correlation was established between RER phenotype and LOH, K-ras or p53 mutations. RER remained a strong predictive factor (hazard ratio for death, 2.89; 95% confidence interval, 2.23-3.79; P = 0.002) after adjustment for all other evaluated factors, including p53, K-ras, LOH, histological type, tumour differentiation and TNM stage, suggesting that microsatellite instability on chromosomes 2p and 3p may play a role in NSCLC progression through a different pathway from the traditional tumour mechanisms of oncogene activation and/or tumour-suppressor gene inactivation

Procaine Inhibits Osteo/Odontogenesis through Wnt/β-Catenin Inactivation

Introduction Periodontitis is a complex pathology characterized by the loss of alveolar bone. The causes and the mechanisms that promote this bone resorption still remain unknown. The knowledge of the critical regulators involved in the alteration of alveolar bone homeostasis is of great importance for developing molecular therapies. Procaine is an anesthetic drug with demethylant properties, mainly used by dentists in oral surgeries. The inhibitor role of Wnt signaling of procaine was described in vitro in colon cancer cells. Methods In this work we evaluated the role of procaine (1 uM) in osteo/odontogenesis of rat bone marrow mesenchymal stem cells. Similarly, the mechanisms whereby procaine achieves these effects were also studied. Results Procaine administration led to a drastic decrease of calcium content, alkaline phosphatase activity, alizarin red staining and an increase in the expression of Matrix Gla Protein. With respect to osteo/odontogenic markers, procaine decreased early and mature osteo/odontogenic markers. In parallel, procaine inhibited canonical Wnt/β-catenin pathway, observing a loss of nuclear β-catenin, a decrease in Lrp5 and Frizzled 3, a significant increase of sclerostin and Gsk3β and an increase of phosphorylated β-catenin. The combination of osteo/ odontogenic stimuli and Lithium Chloride decreased mRNA expression of Gsk3β, recovered by Procaine. Furthermore it was proved that Procaine alone dose dependently increases the expression of Gsk3β and β-catenin phosphorylation. These effects of procaine were also observed on mature osteoblast. Interestingly, at this concentration of procaine no demethylant effects were observed. PLO

Invasión de la especie exótica Rugulopteryx okamurae en Andalucía. II. Foro Alga Invasora

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In vascular smooth muscle cells paricalcitol prevents phosphate-induced Wnt/β-catenin activation

The present study investigates the differential effect of two vitamin D receptor agonists, calcitriol and paricalcitol, on human aortic smooth muscle cells calcification in vitro. Human vascular smooth muscle cells were incubated in a high phosphate (HP) medium alone or supplemented with either calcitriol 10−8M (HP + CTR) or paricalcitol 3·10−8 M (HP + PC). HP medium induced calcification, which was associated with the upregulation of mRNA expression of osteogenic factors such as bone morphogenetic protein 2 (BMP2), Runx2/Cbfa1, Msx2, and osteocalcin. In these cells, activation of Wnt/β-catenin signaling was evidenced by the translocation of β-catenin into the nucleus and the increase in the expression of direct target genes as cyclin D1, axin 2, and VCAN/versican. Addition of calcitriol to HP medium (HP + CTR) further increased calcification and also enhanced the expression of osteogenic factors together with a significant elevation of nuclear β-catenin levels and the expression of cyclin D1, axin 2, and VCAN. By contrast, the addition of paricalcitol (HP + PC) not only reduced calcification but also downregulated the expression of BMP2 and other osteoblastic phenotype markers as well as the levels of nuclear β-catenin and the expression of its target genes. The role of Wnt/β-catenin on phosphate- and calcitriol-induced calcification was further demonstrated by the inhibition of calcification after addition of Dickkopf-related protein 1 (DKK-1), a specific natural antagonist of the Wnt/β-catenin signaling pathway. In conclusion, the differential effect of calcitriol and paricalcitol on vascular calcification appears to be mediated by a distinct regulation of the BMP and Wnt/β-catenin signaling pathways

Cdc42 localized in the CatSper signaling complex regulates cAMP‐dependent pathways in mouse sperm

Sperm acquire the ability to fertilize in a process called capacitation and undergo hyperactivation, a change in the motility pattern, which depends on Ca2+ transport by CatSper channels. CatSper is essential for fertilization and it is subjected to a complex regulation that is not fully understood. Here, we report that similar to CatSper, Cdc42 distribution in the principal piece is confined to four linear domains and this localization is disrupted in CatSper1-null sperm. Cdc42 inhibition impaired CatSper activity and other Ca2+-dependent downstream events resulting in a severe compromise of the sperm fertilizing potential. We also demonstrate that Cdc42 is essential for CatSper function by modulating cAMP production by soluble adenylate cyclase (sAC), providing a new regulatory mechanism for the stimulation of CatSper by the cAMP-dependent pathway. These results reveal a broad mechanistic insight into the regulation of Ca2+ in mammalian sperm, a matter of critical importance in male infertility as well as in contraception.Fil: Luque, Guillermina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Xu, Xinran. State University of Colorado - Fort Collins; Estados UnidosFil: Romarowski, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. State University of Colorado - Fort Collins; Estados UnidosFil: Gervasi, María G.. University of Massachussets; Estados UnidosFil: Orta, Gerardo. Universidad Autonoma de México. Instituto de Biotecnología; MéxicoFil: De la Vega Beltrán, José L.. Universidad Autonoma de México. Instituto de Biotecnología; MéxicoFil: Stival, Cintia Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Gilio, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: D'alotto Moreno, Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Krapf, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Visconti, Pablo E.. University of Massachussets; Estados UnidosFil: Krapf, Diego. State University of Colorado - Fort Collins; Estados UnidosFil: Darszon, Alberto. Universidad Autonoma de México. Instituto de Biotecnología; MéxicoFil: Buffone, Mariano Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Magnesium Inhibits Wnt/β-Catenin Activity and Reverses the Osteogenic Transformation of Vascular Smooth Muscle Cells

Magnesium reduces vascular smooth muscle cell (VSMC) calcification in vitro but the mechanism has not been revealed so far. This work used only slightly increased magnesium levels and aimed at determining: a) whether inhibition of magnesium transport into the cell influences VSMC calcification, b) whether Wnt/β-catenin signaling, a key mediator of osteogenic differentiation, is modified by magnesium and c) whether magnesium can influence already established vascular calcification. Human VSMC incubated with high phosphate (3.3 mM) and moderately elevated magnesium (1.4 mM) significantly reduced VSMC calcification and expression of the osteogenic transcription factors Cbfa-1 and osterix, and up-regulated expression of the natural calcification inhibitors matrix Gla protein (MGP) and osteoprotegerin (OPG). The protective effects of magnesium on calcification and expression of osteogenic markers were no longer observed in VSMC cultured with an inhibitor of cellular magnesium transport (2-aminoethoxy-diphenylborate [2-APB]). High phosphate induced activation of Wnt/β-catenin pathway as demonstrated by the translocation of β-catenin into the nucleus, increased expression of the frizzled-3 gene, and downregulation of Dkk-1 gene, a specific antagonist of the Wnt/β-catenin signaling pathway. The addition of magnesium however inhibited phosphate-induced activation of Wnt/β-catenin signaling pathway. Furthermore, TRPM7 silencing using siRNA resulted in activation of Wnt/β-catenin signaling pathway. Additional experiments were performed to test the ability of magnesium to halt the progression of already established VSMC calcification in vitro. The delayed addition of magnesium decreased calcium content, down-regulated Cbfa-1 and osterix and up-regulated MGP and OPG, when compared with a control group. This effect was not observed when 2-APB was added. In conclusion, magnesium transport through the cell membrane is important to inhibit VSMC calcification in vitro. Inhibition of Wnt/β-catenin by magnesium is one potential intracellular mechanism by which this anti-calcifying effect is achieved

Dietary Mg Supplementation Decreases Oxidative Stress, Inflammation, and Vascular Dysfunction in an Experimental Model of Metabolic Syndrome with Renal Failure

whether a dietary Mg supplementation might attenuate vascular dysfunction through the modulation of oxidative stress and inflammation in concurrent MetS and CKD. Methods: A rat model of MetS (Zucker strain) with CKD (5/6 nephrectomy, Nx) was used. Nephrectomized animals were fed a normal 0.1%Mg (MetS+Nx+Mg0.1%) or a supplemented 0.6%Mg (MetS+Nx+Mg0.6%) diet; Sham-operated rats with MetS receiving 0.1%Mg were used as controls. Results: As compared to controls, the MetS+Nx-Mg0.1% group showed a significant increase in oxidative stress and inflammation biomarkers (lipid peroxidation and aortic interleukin-1b and -6 expression) and Endothelin-1 levels, a decrease in nitric oxide and a worsening in uremia and MetS associated pathology as hypertension, and abnormal glucose and lipid profile. Moreover, proteomic evaluation revealed changes mainly related to lipid metabolism and CVD markers. By contrast, in the MetS+Nx+Mg0.6% group, these parameters remained largely similar to controls. Conclusion: In concurrent MetS and CKD, dietary Mg supplementation reduced inflammation and oxidative stress and improved vascular function

Un esfuerzo de integración para contribuir a la gestión de la invasión del alga Rugulopteryx okamurae en las costas de Andalucía: el foro Alga Invasora

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