6,413 research outputs found

    Investigation into the Role of Platelet Derived Growth Factor (PDGF) in Type I Collagen Glomerulopathy

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    Progressive accumulation of collagen and extracellular matrix (ECM) proteins within renal glomeruli have implications for or result in renal fibrosis and glomerulosclerosis, with both events culminating in renal failure. To model this accumulation the Col1a2-deficient mouse model was used. The Col1a2-deficientmouse model is characterized by a mutation in the a2(I) chain, preventing incorporation into the type I collagen molecule. As a result, an α1(I) collagen chain incorporates into the collagen triple helix forming homotrimeric type I collagen, as opposed to heterotrimeric type I collagen. This change is due to the secondary wound healing response in response to ECM accumulation, fibrosis, or damage. Transforming growth factor-beta (TGF-β) has been studied within this model and demonstrated it was not the initiating molecule in collagen deposition. This study looks at Tumor Necrosis Factor-Alpha (TNF-a) and Platelet Derived Growth Factor (PDGF) as potential mediators of this hypothesized secondary wound healing response. TNF-ais an inflammatory cytokine produced following tissue damage, released by mesangial cells, and has been shown to induce epithelial-to-mesenchymal transition (EMT). Recently, PDGF receptors and ligand upregulation has been shown in other mouse models of renal fibrosis. However, TNF-ashowed no differential staining upon Picrosirius Red (PSR) between experimental and control groups. PDGFR-ββ and PDGF-BB displayed differential labeling in Col1a2-deficient in comparison to age matched wild type animals. The results for PDGF-DD mice were less conclusive when comparing the Col1a2-deficient mice to that of their wild type counterparts

    Complexified sigma model and duality

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    We show that the equations of motion associated with a complexified sigma-model action do not admit manifest dual SO(n,n) symmetry. In the process we discover new type of numbers which we called `complexoids' in order to emphasize their close relation with both complex numbers and matroids. It turns out that the complexoids allow to consider the analogue of the complexified sigma-model action but with (1+1)-worldsheet metric, instead of Euclidean-worldsheet metric. Our observations can be useful for further developments of complexified quantum mechanics.Comment: 15 pages, Latex, improved versio

    Disparity and diversity workshop

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    High temperature–high pressure thermal conductivities of ethylene and propane

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    Thermal conductivities λ of ethylene and propane were measured in the temperature and pressure ranges 400–750 K and 0.1–2.65 MPa (ethylene) and 400–725 K and 0.1 to 0.6 MPa (propane). The data were correlated by expressions of the form λ=λ0(T) ×λp(P), with λ0 being a second order polynomial in temperature and λp a third (ethylene) or a fourth (propane) order polynomial in pressure. The results obtained were compared with previous thermal conductivity measurements.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71313/2/JCPSA6-70-8-3948-1.pd

    Quantum affine Cartan matrices, Poincare series of binary polyhedral groups, and reflection representations

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    We first review some invariant theoretic results about the finite subgroups of SU(2) in a quick algebraic way by using the McKay correspondence and quantum affine Cartan matrices. By the way it turns out that some parameters (a,b,h;p,q,r) that one usually associates with such a group and hence with a simply-laced Coxeter-Dynkin diagram have a meaningful definition for the non-simply-laced diagrams, too, and as a byproduct we extend Saito's formula for the determinant of the Cartan matrix to all cases. Returning to invariant theory we show that for each irreducible representation i of a binary tetrahedral, octahedral, or icosahedral group one can find a homomorphism into a finite complex reflection group whose defining reflection representation restricts to i.Comment: 19 page
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