3,872 research outputs found

    MYC and E1A Oncogenes Alter the Response of PC12 Cells to Nerve Growth Factor and Block Differentiation: A Thesis

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    PC12 rat pheochromocytoma cells respond to nerve growth factor (NGF) by neuronal differentiation and partial growth arrest. Mouse c-myc and adenovirus E1A genes were introduced into PC12 cells to study the influence of these nuclear oncogenes on neuronal differentiation. Expression of myc and E1A blocked morphological differentiation and caused NGF to stimulate rather than inhibit cell proliferation. NGF binding to cell surface receptors, activation of ribosomal S6 kinase, and ornithine decarboxylase induction were similar in myc and E1A expressing clones compared with wild-type PC12 cells, suggesting that changes in the cellular response to NGF were at a post-receptor level. The ability of myc and E1A expression to block the transcription-dependent induction of microtubule associated proteins by NGF further suggested that these genes may inhibit differentiation by interfering with NGP\u27s ability to regulate transcription. These results illustrate that NGF can promote either growth or differentiation of PC12 cells, and that myc or E1A alter the phenotypic responses to growth factors

    Indentation modulus, indentation work and creep of metals and alloys at the macro-scale level: Experimental insights into the use of a primary Vickers hardness standard machine

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    In this work, the experimental method and the calculation model for the determination of indentation moduli, indentation work, and indentation creep of metallic materials, by means of macroscale-level forces provided by a primary hardness standard machine at the National Institute of Metrological Research (INRIM) at the at room temperature were described. Indentation moduli were accurately determined from measurements of indentation load, displacement, contact stiffness and hardness indentation imaging and from the slope of the indentation unloading curve by applying the Doerner-Nix linear model; indentation work, representing the mechanical work spent during the force application of the indentation procedure, was determined by calculating the areas under the loading–unloading indentation curve, through fitting experimental data with a polynomial law. Measurements were performed with a pyramidal indenter (Vickers test). The applied force was provided by a deadweight machine, and the related displacement was measured by a laser interferometric system. Applied forces and the occurring indentation depths were simultaneously measured: The resulting loading–unloading indentation curve was achieved. Illustrative tests were performed on metals and alloy samples. Discussion and comments on the suitability of the proposed method and analysis were reported

    Comparison between tensile properties and indentation properties measured with various shapes indenters of Copper-Chromium-Zirconium alloy at macroscale level

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    In this paper the experimental results of tensile properties and indentationproperties, as a function of pyramidal and spherical indenters, of Copper-Chromium-Zirconium alloy, in the macro-scale range at room temperature, are presented and compared. Measurements are performed on three Cu-Cr-Zr samples in order to evaluate different heat treatments: two samples areaged for 2 hours in a vacuum furnace at 480 °C, 550 °C and one sample is kept as received. The experimental procedures for the measurement of indentation modulus, by using the primary hardness standard machine at INRiM, and tensile modulus, by means of engineering tensile tests at CIRA, aredescribed

    Constraints on new physics from the quark mixing unitarity triangle

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    The status of the Unitarity Triangle beyond the Standard Model including the most recent results on Delta m_s, on dilepton asymmetries and on width differences is presented. Even allowing for general New Physics loop contributions the Unitarity Triangle must be very close to the Standard Model result. With the new measurements from the Tevatron, we obtain for the first time a significant constraint on New Physics in the B_s sector. We present the allowed ranges of New Physics contributions to Delta F=2 processes, and of the time-dependent CP asymmetry in B_s to J/Psi phi decays.Comment: 5 pages, 4 figures. v2: numerical error in Delta Gamma_s/Gamma_s corrected. Plots and tables updated. v3: update after ICHEP06, final version published in Phys Rev Letter

    Update of the Unitarity Triangle Analysis

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    We present the status of the Unitarity Triangle Analysis (UTA), within the Standard Model (SM) and beyond, with experimental and theoretical inputs updated for the ICHEP 2010 conference. Within the SM, we find that the general consistency among all the constraints leaves space only to some tension (between the UTA prediction and the experimental measurement) in BR(B -> tau nu), sin(2 beta) and epsilon_K. In the UTA beyond the SM, we allow for New Physics (NP) effects in (Delta F)=2 processes. The hint of NP at the 2.9 sigma level in the B_s-\bar B_s mixing turns out to be confirmed by the present update, which includes the new D0 result on the dimuon charge asymmetry but not the new CDF measurement of phi_s, being the likelihood not yet released.Comment: 4 pages, 2 figures, Proceedings of the 35th International Conference of High Energy Physics - ICHEP2010 (July 22-28, 2010, Paris

    Cryo-mechanical treatment and hydrometallurgical process for recycling Li-MnO2primary batteries with the direct production of LiMnPO4nanoparticles

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    In this work, an innovative hydrometallurgical recycling route for the recovery of all the materials composing Li-MnO2 primary batteries was proposed. End-of-life batteries were mechanically treated in an innovative pilot plant where a cryogenic crushing was performed. The mechanical treatment allowed for the release of the electrodic powder contained in the batteries with the simultaneous recovery of 44 kg of steel and 18 kg of plastics from 100 kg of batteries. Electrodic powder was employed as the raw material for the synthesis of LiMnPO4 nanoparticles. To obtain the synthesis precursors, selective sequential leaching of Li and Mn was performed. Li was extracted via water washing the electrodic powder and Li2CO3 and a purity of 99% was recovered. The black mass containing Mn oxides was leached using phosphoric acid, which gave a Mn-bearing precursor solution that was directly used for the hydrothermal synthesis of LiMnPO4 nanoparticles. A preliminary materials balance of the process was presented, indicating that the proposed process should be an easy hydrometallurgical route for the recycling of primary lithium batteries. In addition, the simultaneous production of high-value-added products that could be reintroduced into the battery manufacturing chain could ensure the economic feasibility of the process
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