Homogeneous Fermion Superfluid with Unequal Spin Populations

For decades, the conventional view is that an s-wave BCS superfluid can not support uniform spin polarization due to a gap $\Delta$ in the quasiparticle excitation spectrum. We show that this is an artifact of the dismissal of quasiparticle interactions $V_{qp}^{}$ in the conventional approach at the outset. Such interactions can cause triplet fluctuations in the ground state and hence non-zero spin polarization at "magnetic field" $h<\Delta$. The resulting ground state is a pairing state of quasiparticles on the ``BCS vacuum". For sufficiently large $V_{qp}$, the spin polarization of at unitarity has the simple form $m\propto \mu^{1/2}$. Our study is motivated by the recent experiments at Rice which found evidence of a homogenous superfluid state with uniform spin polarization.Comment: 4 pages, 3 figure

The σ\sigma pole in J/ψ→ωπ+π−J/\psi \to \omega \pi^+ \pi^-

Using a sample of 58 million $J/\psi$ events recorded in the BESII detector, the decay $J/\psi \to \omega \pi^+ \pi^-$ is studied. There are conspicuous $\omega f_2(1270)$ and $b_1(1235)\pi$ signals. At low $\pi \pi$ mass, a large broad peak due to the $\sigma$ is observed, and its pole position is determined to be $(541 \pm 39)$ - $i$ $(252 \pm 42)$ MeV from the mean of six analyses. The errors are dominated by the systematic errors.Comment: 15 pages, 6 figures, submitted to PL

Green function techniques in the treatment of quantum transport at the molecular scale

The theoretical investigation of charge (and spin) transport at nanometer length scales requires the use of advanced and powerful techniques able to deal with the dynamical properties of the relevant physical systems, to explicitly include out-of-equilibrium situations typical for electrical/heat transport as well as to take into account interaction effects in a systematic way. Equilibrium Green function techniques and their extension to non-equilibrium situations via the Keldysh formalism build one of the pillars of current state-of-the-art approaches to quantum transport which have been implemented in both model Hamiltonian formulations and first-principle methodologies. We offer a tutorial overview of the applications of Green functions to deal with some fundamental aspects of charge transport at the nanoscale, mainly focusing on applications to model Hamiltonian formulations.Comment: Tutorial review, LaTeX, 129 pages, 41 figures, 300 references, submitted to Springer series "Lecture Notes in Physics

Strengthening mechanisms in thermomechanically processed NbTi-microalloyed steel

The effect of deformation temperature on microstructure and mechanical properties was investigated for thermomechanically processed NbTi-microalloyed steel with ferrite-pearlite microstructure. With a decrease in the finish deformation temperature at 1348 K to 1098 K (1075 °C to 825 °C) temperature range, the ambient temperature yield stress did not vary significantly, work hardening rate decreased, ultimate tensile strength decreased, and elongation to failure increased. These variations in mechanical properties were correlated to the variations in microstructural parameters (such as ferrite grain size, solid solution concentrations, precipitate number density and dislocation density). Calculations based on the measured microstructural parameters suggested the grain refinement, solid solution strengthening, precipitation strengthening, and work hardening contributed up to 32 pct, up to 48 pct, up to 25 pct, and less than 3 pct to the yield stress, respectively. With a decrease in the finish deformation temperature, both the grain size strengthening and solid solution strengthening increased, the precipitation strengthening decreased, and the work hardening contribution did not vary significantly

Ring sideroblasts in AML are associated with adverse risk characteristics and have a distinct gene expression pattern

Contains fulltext : 209362.pdf (publisher's version ) (Open Access

Inhibitory Effects of Urtica thunbergiana Ethanol Extract on Atopic Dermatitis-Induced NC/Nga Mice

Atopic dermatitis (AD) is a chronic, inflammatory skin disease that persists or repeatedly recurs in both childhood and adulthood. Urtica thunbergiana (UT) is an aroma herb with little-known pharmacological effects and anti-inflammatory activities against AD. This study investigated the immunomodulatory efficacy of 50% ethanol-extracted UT in necrosis factor-alpha/interferon-gamma (TNF-&alpha;/IFN-&gamma;)-stimulated HaCaT cells in vitro and AD-Biostir-induced NC/Nga mice in vivo. The results showed that UT exhibits a dose-dependent increase in scavenged free radicals, reaching 76.0% &plusmn; 1.4% of scavenged 1,1-diphenyl-2-picrylhydrazyl at a concentration of 250 &micro;g/mL. In addition, UT significantly downregulated the mRNA expression of the following pro-inflammatory cytokines and chemokines in TNF-&alpha;/IFN-&gamma;-stimulated HaCaT cells: interleukin (IL)-6, IL-8, thymus- and activation-regulated chemokine, macrophage-derived chemokine, and regulated on activation normal T expressed and secreted. UT-treated HaCaT cells showed inhibition of the overexpression of chemokine-regulated signaling molecules, such as nuclear factor-kappa B, inhibitor of kappa B (I&kappa;B&alpha;), signal transducer and activator of transcription 1, and mitogen-activated protein kinases (MAPKs). UT dietary administration in AD-Biostir-induced NC/Nga mice treated and improved AD-like symptoms, such as scales, epidermal thickening, the dermatitis severity score, high trans-epidermal water loss, reduced skin hydration, increased mast cells, elevated serum immunoglobulin E levels, and an enlarged spleen. UT treatment inhibited the expression of phosphorylated forms of MAPKs, nuclear factor of activated T-cells 1, and regulator I&kappa;B&alpha;. It also upregulated filaggrin (FLG) production. Therefore, UT shows high anti-AD activity both in vitro and in vivo, and can be a useful anti-AD agent