Inelastic Coulomb scattering rate of a multisubband Q1D electron gas

In this work, the Coulomb scattering lifetimes of electrons in two coupled quantum wires have been studied by calculating the quasiparticle self-energy within a multisubband model of quasi-one-dimensional (Q1D) electron system. We consider two strongly coupled quantum wires with two occupied subbands. The intrasubband and intersubband inelastic scattering rates are caculated for electrons in different subbands. Contributions of the intrasubband, intersubband plasmon excitations, as well as the quasiparticle excitations are investigated. Our results shows that the plasmon exictations of the first subband are the most important scattering mechanism for electrons in both subbands.Comment: 9 pages, REVTEX, 2 figure

Anomalous magnetic and weak magnetic dipole moments of the τ\tau lepton in the simplest little Higgs model

We obtain analytical expressions, both in terms of parametric integrals and Passarino-Veltman scalar functions, for the one-loop contributions to the anomalous weak magnetic dipole moment (AWMDM) of a charged lepton in the framework of the simplest little Higgs model (SLHM). Our results are general and can be useful to compute the weak properties of a charged lepton in other extensions of the standard model (SM). As a by-product we obtain generic contributions to the anomalous magnetic dipole moment (AMDM), which agree with previous results. We then study numerically the potential contributions from this model to the $\tau$ lepton AMDM and AWMDM for values of the parameter space consistent with current experimental data. It is found that they depend mainly on the energy scale $f$ at which the global symmetry is broken and the $t_\beta$ parameter, whereas there is little sensitivity to a mild change in the values of other parameters of the model. While the $\tau$ AMDM is of the order of $10^{-9}$, the real (imaginary) part of its AWMDM is of the order of $10^{-9}$ ($10^{-10}$). These values seem to be out of the reach of the expected experimental sensitivity of future experiments.Comment: 23 pages, 11 figures, new analysis and References adde

Three-dimensional patchy lattice model: ring formation and phase separation

We investigate the structural and thermodynamic properties of a model of particles with $2$ patches of type $A$ and $10$ patches of type $B$. Particles are placed on the sites of a face centered cubic lattice with the patches oriented along the nearest neighbor directions. The competition between the self-assembly of chains, rings and networks on the phase diagram is investigated by carrying out a systematic investigation of this class of models, using an extension of Wertheim's theory for associating fluids and Monte Carlo numerical simulations. We varied the ratio $r\equiv\epsilon_{AB}/\epsilon_{AA}$ of the interaction between patches $A$ and $B$, $\epsilon_{AB}$, and between $A$ patches, $\epsilon_{AA}$ ($\epsilon_{BB}$ is set to $0$) as well as the relative position of the $A$ patches, i.e., the angle $\theta$ between the (lattice) directions of the $A$ patches. We found that both $r$ and $\theta$ ($60^\circ,90^\circ,$ or $120^\circ$) have a profound effect on the phase diagram. In the empty fluid regime ($r < 1/2$) the phase diagram is re-entrant with a closed miscibility loop. The region around the lower critical point exhibits unusual structural and thermodynamic behavior determined by the presence of relatively short rings. The agreement between the results of theory and simulation is excellent for $\theta=120^\circ$ but deteriorates as $\theta$ decreases, revealing the need for new theoretical approaches to describe the structure and thermodynamics of systems dominated by small rings.Comment: 26 pages, 10 figure

Impacts of in vivo and in vitro exposures to tamoxifen: comparative effects on human cells and marine organisms

Tamoxifen (TAM) is a first generation-SERM administered for hormone receptor-positive (HER+) breast cancer in both pre- and post-menopausal patients and may undergo metabolic activation in organisms that share similar receptors and thus face comparable mechanisms of response. The present study aimed to assess whether environmental trace concentrations of TAM are bioavailable to the filter feeder M. galloprovincialis (100 ng L-1) and to the deposit feeder N. diversicolor (0.5, 10, 25 and 100 ng L-1) after 14 days of exposure. Behavioural impairment (burrowing kinetic), neurotoxicity (AChE activity), endocrine disruption by alkali-labile phosphate (ALP) content, oxidative stress (SOD, CAT, GPXs activities), biotransformation (GST activity), oxidative damage (LPO) and genotoxicity (DNA damage) were assessed. Moreover, this study also pertained to compare TAM cytotoxicity effects to mussels and targeted human (i.e. immortalized retinal pigment epithelium - RPE; and human transformed endothelial cells - HeLa) cell lines, in a range of concentrations from 0.5 ng L-1 to 50 μg L-1. In polychaetes N. diversicolor, TAM exerted remarkable oxidative stress and damage at the lowest concentration (0.5 ng L-1), whereas significant genotoxicity was reported at the highest exposure level (100 ng L-1). In mussels M. galloprovincialis, 100 ng L-1 TAM caused endocrine disruption in males, neurotoxicity, and an induction in GST activity and LPO byproducts in gills, corroborating in genotoxicity over the exposure days. Although cytotoxicity assays conducted with mussel haemocytes following in vivo exposure was not effective, in vitro exposure showed to be a feasible alternative, with comparable sensitivity to human cell line (HeLa).info:eu-repo/semantics/publishedVersio