85 research outputs found

    Growth and texture of Spark Plasma Sintered Al2O3 ceramics: a combined analysis of X-rays and Electron Back Scatter Diffraction

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    Textured alumina ceramics were obtained by Spark Plasma Sintering (SPS) of undoped commercial a-Al2O3 powders. Various parameters (density, grain growth, grain size distribution) of the alumina ceramics, sintered at two typical temperatures 1400{\deg}C and 1700{\deg}C, are investigated. Quantitative textural and structural analysis, carried out using a combination of Electron Back Scattering Diffraction (EBSD) and X-ray diffraction (XRD), are represented in the form of mapping, and pole figures. The mechanical properties of these textured alumina ceramics include high elastic modulus and hardness value with high anisotropic nature, opening the door for a large range of applicationsComment: 16 pages, 6 figures, submitted to J. Appl. Phy

    Human Cytomegalovirus IE1 Protein Elicits a Type II Interferon-Like Host Cell Response That Depends on Activated STAT1 but Not Interferon-γ

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    Human cytomegalovirus (hCMV) is a highly prevalent pathogen that, upon primary infection, establishes life-long persistence in all infected individuals. Acute hCMV infections cause a variety of diseases in humans with developmental or acquired immune deficits. In addition, persistent hCMV infection may contribute to various chronic disease conditions even in immunologically normal people. The pathogenesis of hCMV disease has been frequently linked to inflammatory host immune responses triggered by virus-infected cells. Moreover, hCMV infection activates numerous host genes many of which encode pro-inflammatory proteins. However, little is known about the relative contributions of individual viral gene products to these changes in cellular transcription. We systematically analyzed the effects of the hCMV 72-kDa immediate-early 1 (IE1) protein, a major transcriptional activator and antagonist of type I interferon (IFN) signaling, on the human transcriptome. Following expression under conditions closely mimicking the situation during productive infection, IE1 elicits a global type II IFN-like host cell response. This response is dominated by the selective up-regulation of immune stimulatory genes normally controlled by IFN-γ and includes the synthesis and secretion of pro-inflammatory chemokines. IE1-mediated induction of IFN-stimulated genes strictly depends on tyrosine-phosphorylated signal transducer and activator of transcription 1 (STAT1) and correlates with the nuclear accumulation and sequence-specific binding of STAT1 to IFN-γ-responsive promoters. However, neither synthesis nor secretion of IFN-γ or other IFNs seems to be required for the IE1-dependent effects on cellular gene expression. Our results demonstrate that a single hCMV protein can trigger a pro-inflammatory host transcriptional response via an unexpected STAT1-dependent but IFN-independent mechanism and identify IE1 as a candidate determinant of hCMV pathogenicity

    A low noise, large dynamic range pulse amplifier

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    The ECLine-driver: a flexible, 20MHz, 256 words ECLine generator

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    The ECLine-Driver is a dual 256 words of 16 bits fast ECLine generator fully controlled by CAMAC. Designed to fit requirements of high energy physics experiments, its flexibility makes it a general purpose unit. It is used on the LEP L3 experiment, at CERN, to implement two applications. In the first one, it generates the "trigger detector" response in order to exercise the different trigger processors under experimental conditions. In the second one, it generates some 10000 synchronisation signals required to drive the level-1 energy trigger processor. 70 units are installed on the experiment

    Globalizing practices and university responses: European and Anglo-American differences

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    Investigates the impact that certain globalizing practices have on European and American universities. Due to dwindling resources and the ideology of privatization, universities are becoming more corporatized and managerial. The authors investigate the consequences of these changes on the lives of academics and analyze how globalizing practices such as managerialism, accountability, and employment flexibility penetrate different universities. Globalization is a contested term. It exists in the form of an integrated world economy and global communication networks. Along with this material world, politicians have created a neoliberal ideology that exhorts nation states to open up their economies to free trade, reduce their public sector, and allow market forces to reshape their public agencies. In effect, this means a reduced role for government, lower taxes, and diminishing funds for public institutions like universities. The underlying thesis of this book is that globalization is not an inexorable force. All nations need to debate its consequences. The authors analyze how globalizing practices are penetrating universities. Are they creating a certain uniformity? Are academics adapting to or resisting particular globalizing practices? The premise at the beginning of the study was that European universities were responding differently to globalizing practices than Anglo-American universities. This premise was confirmed as some universities saw certain globalizing practices as inevitable and other universities resisted them. The authors asked academics and key managers how their funding had changed, and which accountability mechanisms their universities adopted. They also investigated the use of the Internet in their teaching. They found differences between European and American universities in their approach to permanent employment. The French and Norwegian universities were maintaining many of their traditional values and only the Dutch university showed some movement towards the globalizing practices, which American universities were more readily adopting

    Psoriatic epidermis is associated with upregulation of CDK 2 and inhibition of CDK 4 activity

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    International audienceBackground: The cyclin-dependent kinases (CDKs) CDK2 and CDK4 are involved in regulation of cell-cycle progression, and psoriasis is characterized by hyperproliferation of basal epidermal cells. CDK inhibitory proteins (CKIs) such as p16INK 4A (p16) bind CDK4/6 kinases and prevent their interaction with D-type cyclins. CKIs such as p21Cip1 (p21) and p27Kip1 (p27) associate with CDK-cyclin complexes and prevent their activation.Objectives: To gain insight into the molecular implication of CDK2 and CDK4 kinases in psoriasis, we sought to characterize expression of these kinases and associated cyclins, as well as of CKIs, and addressed the status of CDK2 and CDK4 activity in human psoriatic epidermis.Methods: A cohort of 24 patients with psoriasis participated in the study. Biopsies were removed from a chronic plaque and from nonlesional skin. CDK2, CDK4, cyclin D1, cyclin E and CKI protein expression was assessed by immunoblotting, immunohistochemistry and immunofluorescence. CDK4 and CDK2 mRNA expression was determined by real-time polymerase chain reaction. Specific kinase activities of CDK2 and CDK4 were evaluated using fluorescent peptide biosensors.Results: CDK2-cyclin E expression and activity were significantly increased in psoriatic epidermis compared with uninvolved adjacent skin. In contrast, CDK4-cyclin D1 activity was inhibited, although its expression was increased in psoriatic epidermis and its transcription slightly inhibited. p27 expression was reduced, while p16 and p21 expression was induced in psoriatic epidermis.Conclusions: Epidermal CDK2 activity is increased in psoriatic epidermis while CDK4 activity is completely inhibited. These alterations are not associated with changes in CDK transcription and instead involve post-translational control mediated by decreased expression of p27 and p16 overexpression, respectively. What's already known about this topic? Cyclin-dependent kinases (CDKs) are involved in cell-cycle progression. The levels of cyclin partners and CDK inhibitors regulate their activity. Psoriasis is a chronic T-cell-driven inflammatory skin disease characterized by hyperproliferation of basal epidermal cells. What does this study add? Thanks to fluorescent peptide biosensors, this study demonstrates that epidermal CDK2 activity is increased in psoriatic epidermis while CDK4 activity is completely inhibited. These alterations involve post-translational control mediated by decreased expression of p27, and p16 overexpression, respectively. What is the translational message? CDK2 and CDK4 are involved in regulation of cell-cycle progression, and psoriasis is characterized by hyperproliferation of basal epidermal cells. Epidermal CDK2 activity is increased in psoriatic epidermis while CDK4 activity is completely inhibited. These alterations are not associated with changes in CDK transcription and instead involve post-translational control mediated by decreased expression of p27 and p16 overexpression, respectively. Pharmacological modulation of CDK2 and CDK4 may constitute a promising therapeutic strategy
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