The Experts below are selected from a list of 164739 Experts worldwide ranked by ideXlab platform
Pierre Eid - One of the best experts on this subject based on the ideXlab platform.
-
Direct Signal transduction via functional interferon-alphabeta receptors in CD34+ hematopoietic stem cells.
Leukemia, 2002Co-Authors: J Giron-michel, D. Weill, G. Bailly, S. Legras, P. C. Nardeux, Bruno Azzarone, M. G. Tovey, Pierre EidAbstract:Direct Signal transduction via functional interferon-αβ receptors in CD34 + hematopoietic stem cells
-
Direct Signal transduction via functional interferon-αβ receptors in CD34^+ hematopoietic stem cells
Leukemia, 2002Co-Authors: J Giron-michel, D. Weill, G. Bailly, S. Legras, P. C. Nardeux, Bruno Azzarone, M. G. Tovey, Pierre EidAbstract:Affinity purified, freshly isolated CD34^+ progenitors were shown to express low levels of type I interferon (IFN) receptors (740 ± 60 binding sites/cell, K _d 0.7 ± 0.04 n M ) determined by Scatchard's analysis using a radiolabelled, neutralizing, monoclonal antibody Directed against the IFNAR1 chain of the human type I IFN receptor. Treatment of freshly isolated (day 0), highly purified (>95% pure) CD34^+ cells with recombinant IFN-α resulted in rapid tyrosine phosphorylation and activation of STAT1, Tyk2 and JAK1 as shown by Western immunoblotting. Similarly, IFN treatment was shown by confocal microscopy to result in rapid nuclear localization of the transcription factors IRF1 and STAT2, demonstrating the presence of functional IFN receptors on freshly isolated (day 0) CD34^+ cells. The number of specific type I IFN receptor binding sites expressed on hematopoietic progenitor cells increased to some 1440 ± 40 per cell after 11 days of cultivation of CD34^+ cells in vitro suggesting that receptor expression increases with cell differentiation. IFN-mediated Signal transduction and the inhibitory effect of IFN-α on 7 or 14 days CFU-GM and BFU-E colony formation was abrogated in the presence of the anti-IFNAR1 mAb, indicating that IFN-α acts Directly on the proliferation of human hematopoietic progenitor cells via receptor activated Signal transduction without excluding the induction of other cytokines or growth factors by residual accessory cells.
Jinhuai Liu - One of the best experts on this subject based on the ideXlab platform.
-
cadmium sulfide modified gce for Direct Signal amplified sensing of dna hybridization
Biophysical Chemistry, 2008Co-Authors: Qing Xia, Xing Chen, Jinhuai LiuAbstract:Abstract A novel DNA hybridization sensor based on nanoparticle CdS modified glass carbon electrode (GCE) was constructed and characterized coupled with Cyclic Voltammogram (CV) and Differential Pulse Voltammogram (DPV) techniques. The mercapto group-linked probe DNA was covalently immobilized onto the CdS layer and exposed to oligonucleotide (ODN) target for hybridization. The structure of DNA sensor was characterized by X-ray diffraction (XRD), field-emission microscopy (FESEM) and X-ray photoelectron spectra (XPS). Sensitive electrical readout achieved by CV and DPV techniques shown that when the target DNA hybridized with probe CdS-ODN conjugates and the double helix formed on the modified electrode, a significant increased response was observed comparing with the bare electrodes. The selectivity of the sensor was tested using a series of matched and certain-point mismatched sequences with concentration grads ranging from 10 − 6 μM to 10 1 μM. The Signal was in good linear with the minus logarithm of target oligonucleotide concentration with detection limit − 6 μM for the Signal amplification. Due to great surface properties, the additional negative charges and space resistance of as-prepared CdS nanoparticles, the sensor was able to robustly discriminate the DNA hybridization responses with good sensitivity and stability.
G Smith - One of the best experts on this subject based on the ideXlab platform.
-
evaluation of Direct Signal suppression for passive radar
IEEE Transactions on Geoscience and Remote Sensing, 2017Co-Authors: J. L. Garry, C. J. Baker, G SmithAbstract:Passive radar (PR) systems must be able to detect the presence of a target Signal many orders of magnitude weaker than the Direct Signal interference (DSI). Due to the continuous nature of most PR Signals, this interference, rather than thermal noise, determines the sensitivity of the system. Suppression of DSI and clutter prior to range-Doppler processing is crucial for maximizing the effective dynamic range, to increase detection range and improve overall system performance. A number of time-domain adaptive filtering techniques have been proposed to mitigate the effects of DSI, with varying levels of success. As such, an investigation of the primary factors affecting suppression performance is presented, using Advanced Television Systems Committee digital television (DTV) waveforms as an example, through simulation and extensive experimental trials. A number of spectral and spatially diverse DTV Signals are considered to analyze suppression performance under a wide range of realistic scenarios. In particular, the fast block least mean squares filter is shown to provide good suppression performance with low computational requirements. Results of this analysis can be used to predict PR performance and stability. Practical metrics, such as suppression runtime and ease of implementation, also serve to counsel selection of DSI mitigation algorithms for experimental systems.
B. Dupeyrat - One of the best experts on this subject based on the ideXlab platform.
-
ICASSP - Speech segmentation and recognition using syntactic methods on the Direct Signal
ICASSP '79. IEEE International Conference on Acoustics Speech and Signal Processing, 1Co-Authors: M. Baudry, B. DupeyratAbstract:The acoustical parameters are progressively extracted from the sampled Signal up to the phonems by use of syntactic methods. The rewriting rules, which are context-sensitive, are controled by the parameters that are evaluated on the Signal itself. This lends the syntactic analysis to a main semantic point. These techniques are applied in time domain to the speech Signal. Some preprocessing is done in order to code the elapsed time between the extrema of the Signal and the extremum aplitudes. Particularly the voiced aeras are analysed pitch synchronous by means of a "formants extractor" which makes use of the extrema. The prosody of the Signal is computed. The phonetic recognition results are given for various classes of french phonems. The are archieved on a mini-computer operating in real time.
J Giron-michel - One of the best experts on this subject based on the ideXlab platform.
-
Direct Signal transduction via functional interferon-alphabeta receptors in CD34+ hematopoietic stem cells.
Leukemia, 2002Co-Authors: J Giron-michel, D. Weill, G. Bailly, S. Legras, P. C. Nardeux, Bruno Azzarone, M. G. Tovey, Pierre EidAbstract:Direct Signal transduction via functional interferon-αβ receptors in CD34 + hematopoietic stem cells
-
Direct Signal transduction via functional interferon-αβ receptors in CD34^+ hematopoietic stem cells
Leukemia, 2002Co-Authors: J Giron-michel, D. Weill, G. Bailly, S. Legras, P. C. Nardeux, Bruno Azzarone, M. G. Tovey, Pierre EidAbstract:Affinity purified, freshly isolated CD34^+ progenitors were shown to express low levels of type I interferon (IFN) receptors (740 ± 60 binding sites/cell, K _d 0.7 ± 0.04 n M ) determined by Scatchard's analysis using a radiolabelled, neutralizing, monoclonal antibody Directed against the IFNAR1 chain of the human type I IFN receptor. Treatment of freshly isolated (day 0), highly purified (>95% pure) CD34^+ cells with recombinant IFN-α resulted in rapid tyrosine phosphorylation and activation of STAT1, Tyk2 and JAK1 as shown by Western immunoblotting. Similarly, IFN treatment was shown by confocal microscopy to result in rapid nuclear localization of the transcription factors IRF1 and STAT2, demonstrating the presence of functional IFN receptors on freshly isolated (day 0) CD34^+ cells. The number of specific type I IFN receptor binding sites expressed on hematopoietic progenitor cells increased to some 1440 ± 40 per cell after 11 days of cultivation of CD34^+ cells in vitro suggesting that receptor expression increases with cell differentiation. IFN-mediated Signal transduction and the inhibitory effect of IFN-α on 7 or 14 days CFU-GM and BFU-E colony formation was abrogated in the presence of the anti-IFNAR1 mAb, indicating that IFN-α acts Directly on the proliferation of human hematopoietic progenitor cells via receptor activated Signal transduction without excluding the induction of other cytokines or growth factors by residual accessory cells.