47 research outputs found
Charge and current-sensitive preamplifiers for pulse shape discrimination techniques with silicon detectors
New charge and current-sensitive preamplifiers coupled to silicon detectors
and devoted to studies in nuclear structure and dynamics have been developed
and tested. For the first time shapes of current pulses from light charged
particles and carbon ions are presented. Capabilities for pulse shape
discrimination techniques are demonstrated.Comment: 14 pages, 12 figures, to be published in Nucl. Inst. Meth.
Characterization and localization of partial-discharge-induced pulses in fission chambers designed for sodium-cooled fast reactors
During the operation of the Superphenix and Phenix reactors, an aberrant electrical signal was detected from the fission chambers used for neutron flux monitoring. This signal, thought to be due to partial electrical discharge (PD) is similar to the signal resulting from neutron interactions, and is generated in fission chambers at temperatures above 400°C. This paper reports work on the characterization and localization of the source of this electrical signal in a High Temperature Fission Chamber (HTFC). The dependence of the shape of the PD or neutron signal on the various experimental parameters (nature and pressure of the chamber filling gas, electrode gap distance, and fission chamber geometry) are described. Next, experiments designed to identify the location within the chambers where the PD are being generated are presented in way to propose changes to the fission chamber in order to reduce or eliminate the PD signal
Protein and lipid MALDI profiles classify breast cancers according to the intrinsic subtype
<p>Abstract</p> <p>Background</p> <p>Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) has been demonstrated to be useful for molecular profiling of common solid tumors. Using recently developed MALDI matrices for lipid profiling, we evaluated whether direct tissue MALDI MS analysis on proteins and lipids may classify human breast cancer samples according to the intrinsic subtype.</p> <p>Methods</p> <p>Thirty-four pairs of frozen, resected breast cancer and adjacent normal tissue samples were analyzed using histology-directed, MALDI MS analysis. Sinapinic acid and 2,5-dihydroxybenzoic acid/α-cyano-4-hydroxycinnamic acid were manually deposited on areas of each tissue section enriched in epithelial cells to identify lipid profiles, and mass spectra were acquired using a MALDI-time of flight instrument.</p> <p>Results</p> <p>Protein and lipid profiles distinguish cancer from adjacent normal tissue samples with the median prediction accuracy of 94.1%. Luminal, HER2+, and triple-negative tumors demonstrated different protein and lipid profiles, as evidenced by permutation <it>P </it>values less than 0.01 for 0.632+ bootstrap cross-validated misclassification rates with all classifiers tested. Discriminatory proteins and lipids were useful for classifying tumors according to the intrinsic subtype with median prediction accuracies of 80.0-81.3% in random test sets.</p> <p>Conclusions</p> <p>Protein and lipid profiles accurately distinguish tumor from adjacent normal tissue and classify breast cancers according to the intrinsic subtype.</p
Identification of Differentially Expressed Proteins in the Serum of Colorectal Cancer Patients Using 2D-DIGE Proteomics Analysis
Description of current pulses induced by heavy ions in silicon detectors
International audienceThe polarization of the electron-hole pairs induced by 80 MeV View the MathML source ions in a silicon detector was considered and connected to the relative dielectric permittivity. The dissociation of pairs was supposed to take place with a constant probability in a time unit. The exact coordinate dependence of the modified electric field, inside and outside the ion range, was found as the solution of the one-dimensional Maxwell's equation for the electric field in this inhomogeneous medium. The improvement of the current signal simulation with that time-dependent treatment is encouraging, as compared to a prompt carrier collection in an undisturbed electric field
Dye-attached magnetic poly(hydroxyethyl methacrylate) nanospheres for albumin depletion from human plasma
Dielectric polarization and electric field distorsion due to heavy ions impinging on silicon detectors
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