31 research outputs found

    Direct measure of the exciton formation in quantum wells from time resolved interband luminescence

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    We present the results of a detailed time resolved luminescence study carried out on a very high quality InGaAs quantum well sample where the contributions at the energy of the exciton and at the band edge can be clearly separated. We perform this experiment with a spectral resolution and a sensitivity of the set-up allowing to keep the observation of these two separate contributions over a broad range of times and densities. This allows us to directly evidence the exciton formation time, which depends on the density as expected from theory. We also evidence the dominant contribution of a minority of excitons to the luminescence signal, and the absence of thermodynamical equilibrium at low densities

    Telomeres are shorter in myocardial infarction patients compared to healthy subjects: correlation with environmental risk factors

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    Shorter telomeres have been reported in premature myocardial infarction (MI) patients. Our work aimed at confirming the association of shorter telomere with MI in two case–control studies and in familial hypercholesterolemia (FH) patients with coronary heart disease (CHD). The HIFMECH study compared 598 white male patients (<60 years) who survived a first MI and 653 age-matched controls from North and South Europe. Additionally, from the UK, 413 coronary artery bypass graft (CABG) patients and two groups of 367 and 94 FH patients, of whom 145 and 17 respectively had premature CHD, were recruited. Leukocyte telomere length (LTL) was measured using a real-time polymerase chain reaction-based method. In HIFMECH, LTL was significantly shorter in subjects from the North (7.99 kb, SD 4.51) compared to the South (8.27 kb, SD 4.14; p = 0.02) and in cases (7.85 kb, SD 4.01) compared to controls (8.04 kb, SD 4.46; p = 0.04). In the CABG study, LTL was significantly shorter (6.89 kb, SD 4.14) compared to the HIFMECH UK controls (7.53, SD 5.29; p = 0.007). In both samples of FH patients, LTL was shorter in those with CHD (overall 8.68 kb, SD 4.65) compared to the non-CHD subjects (9.23 kb, SD 4.83; p = 0.012). Apart from a consistent negative correlation with age, LTL was not associated across studies with any measured CHD risk factors. The present data confirms that subjects with CHD have shorter telomeres than controls and extends this to those with monogenic and polygenic forms of CHD

    The role of GRHL2 and epigenetic remodeling in epithelial–mesenchymal plasticity in ovarian cancer cells

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    10.1038/s42003-019-0506-3Communications Biology2127

    Direct observation of longitudinal spatial hole burning in semiconductor optical amplifiers with injection

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    Measurements of spontaneous emission from InGaAsP semiconductor optical amplifiers provide information on both the carrier density and temperature. By spatially resolving the light emitted along the active layer of the device, we find evidence of longitudinal spatial hole burning which results from amplified spontaneous emission in the structure and is modified by the injected optical signal. Under injection, we also observe pronounced asymmetry of the amplified spontaneous emission intensity from the two facets which we relate to the carrier density profile. The experimental results are in good agreement with numerical simulations. An analysis of the measured spectra reveals an unexpected very high temperature (400 K) and its decrease by at least 35 K in the middle of the device when light is injected. (C) 2001 American Institute of Physics

    Combined RNAi and localization for functionally dissecting long noncoding RNAs

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    Whereas methods to comprehensively study cellular roles of protein-coding genes are available, techniques to systematically investigate long noncoding RNAs (lncRNAs), which have been implicated in diverse biological pathways, are limited. Here we report combined knockdown and localization analysis of noncoding RNAs (c-KLAN) that merges functional characterization and localization approaches to study lncRNAs. Using this technique we identified transcripts that regulate mouse embryonic stem cell identity

    Combined RNAi and localization for functionally dissecting long non-coding RNAs

    No full text
    Whereas methods to comprehensively study cellular roles of protein-coding genes are available, techniques to systematically investigate long noncoding RNAs (lncRNAs), which have been implicated in diverse biological pathways, are limited. Here we report combined knockdown and localization analysis of noncoding RNAs (c-KLAN) that merges functional characterization and localization approaches to study lncRNAs. Using this technique we identified transcripts that regulate mouse embryonic stem cell identity
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