63 research outputs found
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 sĂ©ries dâĂ©chantillons de la phase supraconductrice YBa2(Cu1-xTix)Oy (x=0,00 ;0,01 ; 0,03 ; 0,06 ; 0,10 ; 0,20 ; 0,25) ont Ă©tĂ© Ă©laborĂ©s par la mĂ©thode de rĂ©action Ă lâĂ©tat solide. Lâeffet de diffĂ©rents cycles de recuit sur la substitution du cuivre par le titane dans lâYBCO a Ă©tĂ© faite Ă travers des mesures de rĂ©sistivitĂ© Ă©lectrique en absence et en prĂ©sence du champ magnĂ©tique. Trois cycles de recuit ont Ă©tĂ© considĂ©rĂ©s : le cycle 2T, le cycle 3T et le cycle 4T. Les rĂ©sultats obtenus montrent quâen absence du champ magnĂ©tique, la substitution augmente la rĂ©sistivitĂ© de lâĂ©tat normal de tous les cycles. Les mesures de rĂ©sistivitĂ© Ă©lectrique en prĂ©sence du champ magnĂ©tique ont Ă©tĂ© faites avec les Ă©chantillons contenant les taux de substitution suivants : 0%, 1% et 3%. Le champ magnĂ©tique rĂ©duit la tempĂ©rature de transition supraconductrice Ă©largissant ainsi la zone de transition supraconductrice vers les basses tempĂ©ratures. Ceci Ă cause du dĂ©placement des vortex thermiquement activĂ©s. Les lignes dâirrĂ©versibilitĂ© qui dĂ©limitent les zones liquide de vortex et solide de vortex, dĂ©duites des courbes de magnĂ©to rĂ©sistivitĂ©, montrent que pour 0% et 1% de substitution, les Ă©chantillons du cycle 4T prĂ©sentent un meilleur ancrage de vortex. A 3% du taux de titane, ce sont les Ă©chantillons du cycle 2T qui prĂ©sentent un meilleur ancrage de vortex. Les Ă©chantillons du cycle 3T montrent peu dâaptitude Ă lâancrage de vortex.Mots clĂ©s: YBa2(Cu1-xTix)Oy , substitution, cuivre, titane, magnĂ©torĂ©sistance, 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
La patrimonialisation en faveur des paysages viticoles de la plaine du Mornag : un nouvel axe de développement local d'un territoire à des conflits d'usage
Proposition de recherche comparative de la recomoposition des usages de la montagne méditerranéenne autour de mines abandonnées au 20Úme siÚcle : Moyen Atlas, Pyrénées, Piémont tunisien, FONCIMED. Réseau de recherche et d'échange sur le foncier méditerranéen
International audienc
Comparative study of nano-sized particles CoFe2O4 effects on superconducting properties of Y-123 and Y-358
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-BacÂź 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)
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