18 research outputs found

    Trapping in irradiated p-on-n silicon sensors at fluences anticipated at the HL-LHC outer tracker

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    The degradation of signal in silicon sensors is studied under conditions expected at the CERN High-Luminosity LHC. 200 ÎĽ\mum thick n-type silicon sensors are irradiated with protons of different energies to fluences of up to 3â‹…10153 \cdot 10^{15} neq/cm2^2. Pulsed red laser light with a wavelength of 672 nm is used to generate electron-hole pairs in the sensors. The induced signals are used to determine the charge collection efficiencies separately for electrons and holes drifting through the sensor. The effective trapping rates are extracted by comparing the results to simulation. The electric field is simulated using Synopsys device simulation assuming two effective defects. The generation and drift of charge carriers are simulated in an independent simulation based on PixelAV. The effective trapping rates are determined from the measured charge collection efficiencies and the simulated and measured time-resolved current pulses are compared. The effective trapping rates determined for both electrons and holes are about 50% smaller than those obtained using standard extrapolations of studies at low fluences and suggests an improved tracker performance over initial expectations

    Aqueous extract of Arbutus unedo inhibits STAT1 activation in human breast cancer cell line MDA-MB-231 and human fibroblasts through SHP2 activation

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    Arbutus unedo L. has been for a long time employed in traditional and popular medicine as an astringent, diuretic, urinary anti-septic, and more recently, in the therapy of hypertension and diabetes. Signal transducer and activator of transcription 1 (STAT1) is a fascinating and complex protein with multiple yet contrasting transcriptional functions. Although activation of this nuclear factor is finely regulated in order to control the entire inflammatory process, its hyperactivation or time-spatially erroneous activation may lead to exacerbation of inflammation. The modulation of this nuclear factor, therefore, has recently been considered as a new strategy in the treatment of inflammatory diseases. In this study, we present data showing that the aqueous extract of Arbutus unedo's leaves exerts inhibitory action on interferon-\u3b3 (IFN- \u3b3)-elicited activation of STAT1, both in human breast cancer cell line MDA-MB-231 and in human fibroblasts. This down-regulation of STAT1 is shown to result from a reduced tyrosine phosphorylation of STAT1 protein. Evidence is also presented indicating that the inhibitory effect of this extract may be mediated through enhancement of tyrosine phosphorylation of SHP2 tyrosine phosphatase. The modulation of this nuclear factor turns out into the regulation of the expression of a number of genes involved in the inflammatory response such as inducible nitric oxide synthase (iNOS) and intercellular adhesion molecule-1 (ICAM-1). Taken together, our results suggest that the employment of the Arbutus unedo aqueous extract is promising, at least, as an auxiliary anti-inflammatory treatment of diseases in which STAT1 plays a critical role

    Nitric oxide mediates anti-inflammatory action of extracorporeal shock waves

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    Here, we show that extracorporeal shock waves (ESW), at a low energy density value, quickly increase neuronal nitric oxide synthase (nNOS) activity and basal nitric oxide (NO) production in the rat glioma cell line C6. In addition, the treatment of C6 cells with ESW reverts the decrease of nNOS activity and NO production induced by a mixture of lipopolysaccharides (LPS), interferon-γ (IFN-γ) plus tumour necrosis factor-α (TNF-α). Finally, ESW treatment efficiently downregulates NF-κB activation and NF-κB-dependent gene expression, including inducible NOS and TNF-α. The present report suggests a possible molecular mechanism of the anti-inflammatory action of ESW treatment

    Nitric oxide mediates anti-inflammatory action of extracorporeal shock waves

    No full text
    Here, we show that extracorporeal shock waves (ESW), at a low energy density value, quickly increase neuronal nitric oxide synthase (nNOS) activity and basal nitric oxide (NO) production in the rat glioma cell line C6. In addition, the treatment of C6 cells with ESW reverts the decrease of nNOS activity and NO production induced by a mixture of lipopolysaccharides (LPS), interferon-γ (IFN-γ) plus tumour necrosis factor-α (TNF-α). Finally, ESW treatment efficiently downregulates NF-κB activation and NF-κB-dependent gene expression, including inducible NOS and TNF-α. The present report suggests a possible molecular mechanism of the anti-inflammatory action of ESW treatment

    alpha-Bisabolol, a nontoxic natural compound, strongly induces apoptosis in glioma cells.

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    In this study, alpha-bisabolol, a sesquiterpene alcohol present in natural essential oil, was found to have a strong time- and dose-dependent cytotoxic effect on human and rat glioma cells. After 24 h of treatment with 2.5-3.5 microM alpha-bisabolol, the viability of these cells was reduced by 50% with respect to untreated cells. Furthermore, the viability of normal rat glial cells was not affected by treatment with alpha-bisabolol at the same concentrations as above. Glioma cells treated with high concentration of alpha-bisabolol (10 microM) resulted in a 100% cell death. Judging from hypo-G1 accumulation, poly(ADP-ribose) polymerase cleavage, and DNA ladder formation, the cytotoxicity triggered by alpha-bisabolol resulted from apoptosis induction. Moreover, the dissipation of mitochondrial-inner transmembrane potential and the release of cytochrome c from mitochondria indicated that, in these glioma cells, apoptosis occurred through an intrinsic pathway. As pointed out by the experimental results, alpha-bisabolol may be considered a novel compound able to inhibit glioma cell growth and survival

    Alpha-Bisabolol, a non toxic natural compound, strongly induces apoptosis in glioma cells

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    In this study, a-bisabolol, a sesquiterpene alcohol present in natural essential oil, was found to have a strong time- and dosedependent cytotoxic effect on human and rat glioma cells. After 24 h of treatment with 2.5\u20133.5 lM a-bisabolol, the viability of these cells was reduced by 50% with respect to untreated cells. Furthermore, the viability of normal rat glial cells was not affected by treatment with a-bisabolol at the same concentrations as above. Glioma cells treated with high concentration of a-bisabolol (10 lM) resulted in a 100% cell death. Judging from hypo-G1 accumulation, poly(ADP-ribose) polymerase cleavage, and DNA ladder formation, the cytotoxicity triggered by a-bisabolol resulted from apoptosis induction. Moreover, the dissipation of mitochondrialinner transmembrane potential and the release of cytochrome c from mitochondria indicated that, in these glioma cells, apoptosis occurred through an intrinsic pathway. As pointed out by the experimental results, a-bisabolol may be considered a novel compound able to inhibit glioma cell growth and surviva
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