Effect of annealing treatments on normal state resistivity of YBa2(Cu1-xTix)3Oy superconductor in bipolaron model

Samples of YBa2(Cu1-xTix)3Oy superconductor with x=0.00 , 0.01, 0.03 have been prepared by solide state reaction method. The effect of annealing treatments on normal electrical resistivity has been done using the bipolaron model. The results of this study show the increase of localized charge when the dopant content increases and the reduction of this localization with annealing treatment.Keywords: YBa2(Cu1-xTix)3Oy superconductor, normal state, bipolaro

The bipolaron model in transport properties of YBa2Cu3Oy superconductor prepared by adding Pr2Co7 magnetic nanoparticles

Samples with the addition of ferromagnetic nanoparticles of Pr2Co7 on YBa2Cu3Oy (YBCO) polycrystalline superconductor were prepared by the standard solid state reaction method. The analysis of x-ray diffraction patterns by Rietveld refinement indicates orthorhombique to tetragonal phase transformation and oxygen rate reduction from x=0.3% of Pr2Co7 content. Resistivity at room temperature increases as Pr2Co7 content increases. The normal state resistivity versus temperature was analyzed properly by the bipolaron model. It suggested the increase of mobile charge localization with Pr2Co7 content.Keywords: Pr2Co7 ferromagnetic nanoparticles, high temperature superconductor, bipolaron model, localization of mobile charg

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.

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

Etude de la magnetoresistance du compose supraconducteur YBa2(Cu1-xTix)3Oy suite a un multicycle de traitement thermique

Des séries d’échantillons de la phase supraconductrice YBa2(Cu1-xTix)Oy (x=0,00 ;0,01 ; 0,03 ; 0,06 ; 0,10 ; 0,20 ; 0,25) ont été élaborés par la méthode de réaction à l’état solide. L’effet de différents cycles de recuit sur la substitution du cuivre par le titane dans l’YBCO a été faite à travers des mesures de résistivité électrique en absence et en présence du champ magnétique. Trois cycles de recuit ont été considérés : le cycle 2T, le cycle 3T et le cycle 4T. Les résultats obtenus montrent qu’en absence du champ magnétique, la substitution augmente la résistivité de l’état normal de tous les cycles. Les mesures de résistivité électrique en présence du champ magnétique ont été faites avec les échantillons contenant les taux de substitution suivants : 0%, 1% et 3%. Le champ magnétique réduit la température de transition supraconductrice élargissant ainsi la zone de transition supraconductrice vers les basses températures. Ceci à cause du déplacement des vortex thermiquement activés. Les lignes d’irréversibilité qui délimitent les zones liquide de vortex et solide de vortex, déduites des courbes de magnéto résistivité, montrent que pour 0% et 1% de substitution, les échantillons du cycle 4T présentent un meilleur ancrage de vortex. A 3% du taux de titane, ce sont les échantillons du cycle 2T qui présentent un meilleur ancrage de vortex. Les échantillons du cycle 3T montrent peu d’aptitude à l’ancrage de vortex.Mots clés: YBa2(Cu1-xTix)Oy , substitution, cuivre, titane, magnétorésistance, vortexEnglish Title: Magnetoresistance study of YBa2(Cu1-xTix)3Oy superconductor compound as a result of thermal multiprocessing treatmentEnglish AbstractA series of YBa2(Cu1-xTix)Oy (x=0.00, 0.01, 0.03, 0.06 , 0,10 , 0.20, 0.25) superconductor phase have been elaborated using solid state reaction method. The effect of annealing treatments of copper substitution by titanium in YBCO is performed across electrical resistivity measurement out of and in magnetic field. Three multiprocessing thermal annealing are considered : 2T, 3T and 4T. The results show that in absence of magnetic field, the substitution increases the normal state resistivity of the whole samples. The magneto resistivity measurements have been done with the samples contained 0%, 1% and 3% of titanium. The magnetic field reduces the superconductor transition temperature enlarging the transition zone to the low temperature. This is explained by the movement of vortex thermally activated. The irreversibility line which separates the liquid vortex area and the solid vortex area, show that, the 4T multiprocessing samples with 0% and 1% of titanium contain are more efficient in vortex pining than those of 2T and 3T. At 3% of titanium contain, 2T multiprocessing samples are more efficient in vortex pining. 3T multiprocessing samples are not efficient in vortex pining.Keywords: YBa2(Cu1-xTix)Oy , substitution, copper, titanium, magneto resistivity, flu

Proposition de recherche comparative de la recomoposition des usages de la montagne méditerranéenne autour de mines abandonnées au 20ème siècle : Moyen Atlas, Pyrénées, Piémont tunisien, FONCIMED. Réseau de recherche et d'échange sur le foncier méditerranéen

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Characterization of Coxsackievirus B4 virus-like particles VLP produced by the recombinant baculovirus-insect cell system expressing the major capsid protein

Coxsackievirus B4 (CV-B4) is suspected to be an environmental factor that has the intrinsic capacity to damage the pancreatic beta cells and therefore causes insulitis and type 1 diabetes (T1D). Although vaccination against CV-B4 could reduce the incidence of this chronic auto-immune disease, there is currently no therapeutic reagent or vaccine in clinical use. By the employment of the Bac-to-Bac® vector system to express the major viral capsid protein, we contributed towards the development of a CV-B4 vaccine by producing CV-B4 virus-like particles (VLPs) from recombinant baculovirus in infected insect cells. In fact Western blot and Immunofluorescence analysis detected the viral protein 1 (VP1) in the cells resulting from the construction of a recombinant bacmid DNA carrying the key immunogenic protein then transfected in the insect cells. Sucrose gradient ultracentrifugation fractions of the infected cell lysates contained the recombinant protein and the electron microscopy demonstrated the presence of VLPs in these sucrose fractions. This study clearly shows for the first time the expression of CVB4 VP1 structure protein alone can form VLPs in the baculovirus-infected insect cell keeping conserved both characteristics and morphology.Authors acknowledge the Tunisian Ministry of Higher Education and Scientific Research (UR17ES30) and the Deanship of Scientific Research at King Faisal University for the financial support under Nasher Track (Grant No. 186390)