Resonant and crossover phenomena in a multiband superconductor tuning the chemical potential near a band edge

Resonances in the superconducting properties, in a regime of crossover from BCS to mixed Bose-Fermi superconductivity, are investigated in a two-band superconductor where the chemical potential is tuned near the band edge of the second mini-band generated by quantum confinement effects. The shape resonances at T=0 in the superconducting gaps (belonging to the class of Feshbach-like resonances) is manifested by interference effects in the superconducting gap at the first large Fermi surface when the chemical potential is in the proximity of the band edge of the second mini-band. The case of a superlattice of quantum wells is considered and the amplification of the superperconducting gaps at the 3D-2D Fermi surface topological transition is clearly shown. The results are found to be in good agreement with available experimental data on a superlattice of honeycomb boron layers intercalated by Al and Mg spacer layers.Comment: 13 pages, 9 image

Finite Elements Analysis of an Electrochemical Coating Process of an Irregularly Shaped Cathode with COMSOL Multiphysics(R)

The overall goal of this work is the use of COMSOL Multiphysics® in the modelling of the current density distributions for the electrodeposition of Aluminium coatings from Ionic Liquids baths. The local current distribution is strongly dependant on the conductivity, on the distribution of concentrations and on the geometry of the galvanic cell, such a calculation can only be performed by the numerical solution of the PDE’s governing the system. This work approach is to exploit computational techniques based on the well-known FEA (Finite Elements Analysis) to obtain stationary and dynamical solutions of such problem. The ability to predict the local current density on an electrode is crucial to eventually evidence portions where the deposition may be invalidated.</jats:p

Subclinical Hypothyroidism: behavioral and psychophysiological characteristics.A pilot study

Background: Clinical hypothyroidism affects various aspects of cognitive and affective brain function. The most severe hypothyroidism may also mimic a picture of melancholic depression and dementia. Subclinical hypothyroidism (SHT) is characterized by elevated TSH levels despite normal thyroid hormone concentrations. The aim of this research is to verify the presence of a typical psychophysiological pattern in SHT patients. Methods: Since 1998 fifty patients who underwent surgeries at the Department of Endocrinology, University of Pisa, diagnosed with SHT, were subsequently recruited. Subjects underwent an inspection of the reported symptoms using the Crown & Crisp Experiential Index, and a psychophysiological assessment with a simultaneous recording of the parameters Skin Conductance Level/ Response (SCL/SCR), Surface Frontal Electromyogram (EMG), Peripheral Temperature (PT), Heart Rate (HR). As a control group, fifty subjects without endocrine disorders were subsequently recruited. Results: Data shows little difference in levels in hormonal assays except for TSH. There is also a significant elevation of some of the CCEI subscales: Anxiety, Depression, and Somatic Complaints. At the autonomic level, there is a general pattern of excessive arousal with significant differences in SCL/SCR, HR, and PT. Conclusions: A first data interpretation is that in sub-clinical hypothyroidism, the body tries to support and integrate the general lack of energy with an acceleration of the autonomic activity. This condition of initial arousal could be a useful indicator in order to monitor the treatment course and its effectiveness on the pathological evolution

Perturbation of symmetric 3-RPR manipulators and asymptotic singularities

International audienceSmall perturbations can affect the kinematic properties of manipulators with non-generic architecture. We study in this paper the perturbations of symmetric planar 3-RPR manipulators. We show in particular that one can obtain any of the three possible stable types of behaviour of 3-RPR manipulators for large values of the lengths of the legs

A two-step immunomagnetic microbead-based method for the isolation of human primary skin telocytes/CD34+ stromal cells

Telocytes (TCs), commonly referred to as TCs/CD34+ stromal cells, are a peculiar type of interstitial cells with distinctive morphologic traits that are supposed to exert several biological functions, including tissue homeostasis regulation, cell-to-cell signaling, immune surveillance, and reparative/regenerative effects. At present, the majority of studies investigating these cells are mainly descriptive and focus only on their morphology, with a consequent paucity of functional data. To gain relevant insight into the possible functions of TCs, in vitro analyses are clearly required, but currently, the protocols for TC isolation are only at the early stages and not fully standardized. In the present in vitro study, we describe a novel methodology for the purification of human primary skin TCs through a two-step immunomagnetic microbead-based cell separation (i.e., negative selection for CD31 followed by positive selection for CD34) capable of discriminating these cells from other connective tissue-resident cells on the basis of their different immunophenotypic features. Our experiments clearly demonstrated that the proposed method allows a selective purification of cells exhibiting the peculiar TC morphology. Isolated TCs displayed very long cytoplasmic extensions with a moniliform silhouette (telopodes) and presented an immunophenotypic profile (CD31&minus;/CD34+/PDGFR&alpha;+/vimentin+) that unequivocally differentiates them from endothelial cells (CD31+/CD34+/PDGFR&alpha;&minus;/vimentin+) and fibroblasts (CD31&minus;/CD34&minus;/PDGFR&alpha;+/vimentin+). This novel methodology for the isolation of TCs lays the groundwork for further research aimed at elucidating their functional properties and possible translational applications, especially in the field of regenerative medicine

Temporal Dynamics of Memory Trace Formation in the Human Prefrontal Cortex

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On the helium content of Galactic globular clusters via the R parameter

We estimate the empirical R parameter in 26 Galactic Globular Clusters covering a wide metallicity range, imaged by WFPC2 on board the HST. The improved spatial resolution permits a large fraction of the evolved stars to be measured and permits accurate assessment of radial populaton gradients and completeness corrections. In order to evaluate both the He abundance and the He to metal enrichment ratio, we construct a large set of evolutionary models by adopting similar metallicities and different He contents. We find an absolute He abundance which is lower than that estimated from spectroscopic measurements in HII regions and from primordial nucleosynthesis models. This discrepancy could be removed by adopting a C12O16 nuclear cross section about a factor of two smaller than the canonical value, although also different assumptions for mixing processes can introduce systematical effects. The trend in the R parameter toward solar metallicity is consistent with an upper limit to the He to metal enrichment ratio of the order of 2.5.Comment: accepted for pubblication on Ap

Antiviral activity of fecal water samples from HIV-1 infected subjects treated with a specific probiotic formulation

Objectives: The aim of the study was to investigate if the supplementation with multistrain probiotics may be able to modulate T cell response in HIV-1 infected patients and to evaluate the anti-HIV activity of probiotic by studying fecal water (FW) samples. Methods: Three HIV-1-positive patients (Pt1, Pt2 and Pt3) on long-term suppressive combined antiretroviral therapy (cART) received a specific multi-strain probiotic supplementation (Vivomixx ®), for six months (T6). Levels of T cell subsets were evaluated by flow cytometry. Anti- HIV activity of FW samples was evaluated in vitro. Results: CD4+ T cells levels increased in all HIV-1 infected patients whereas activation markers (CD38 and HLA-DR) were decreased both on CD4+ and CD8+ T cells. FW samples presented an increased inhibitory activity against HIV-1 compared to T0 (FW-Pt1: T0 =40%, T6 = 65% of reduction; FW Pt2: T0 = 26%, T6 = 46% of reduction; FW Pt3: T0 = 47%, T6 = 94% of reduction). Discussion: Our data suggest that the administration of the specific probiotic formulation improves the antiviral status of people living with HIV-1 under cART, also modulating T cell response. Conclusion: Anti-HIV activity of FW may have several public health and social implications for sexually transmitted diseases that need to be further explored