Possible superconductivity above 25 K in single crystalline Co-doped BaFe2_{2}As2_{2}

We present superconducting properties of single crystalline Ba(Fe$_{0.9}$Co$_{0.1}$)$_{2}$As$_{2}$ by measuring magnetization, resistivity, upper critical field, Hall coefficient, and magneto-optical images. The magnetization measurements reveal fish-tail hysteresis loop at high temperatures and relatively high critical current density above $J_{c}=10^{5}$ A/cm$^{2}$ at low temperatures. Upper critical field determined by resistive transition is anisotropic with anisotropic parameter $\sim$ 3.5. Hall effect measurements indicate that Ba(Fe$_{0.9}$Co$_{0.1}$)$_{2}$As$_{2}$ is a multiband system and the mobility of electron is dominant. The magneto-optical imaging reveals prominent Bean-like penetration of vortices although there is a slight inhomogeneity in a sample. Moreover, we find a distinct superconductivity above 25 K, which leads us to speculate that higher transition temperature can be realized by fine tuning Co-doping level.Comment: 4 pages, 5 figure

Chinese herbal medicine and prednisone increase proportion of splenic CD4+CD25-FOXP3+ cells and alleviate glomerular lesion in MRL/LPRmice

Objective: This study investigated the effects of Chinese herbal medicine and prednisone onCD4+FoxP3+ T cells (Tregs) and Th17 cells in the MRL/lpr mouse model of systemic lupus erythematosus.Methods: MRL/lpr mice were treated with herbal medicine (yin-nourishing and heat-clearing therapy), prednisone, and a combination of both for 7 weeks. The proportions of CD4+CD25-FOXP3+ cells, CD4+CD25-FOXP3+ cells, and CD4+IL-17+ cells in splenic mononuclear cell suspension were determined by flow cytometry. Histological slices of kidneys were stained by H&E, PAS, and Masson’s method. Activity indexes (AI) of glomerular lesions were scored.Results: The result showed that both herbal medicine and prednisone significantly increased the proportion of CD4+CD25-FOXP3+ cells (P<0.05), but lowered the proportion of CD4+CD25-FOXP3+ cells (P<0.05) and CD4+IL-17+ cells (P<0.05) in MRL/lpr mice. Consequently, CD4+CD25-FOXP3+ cells became dominant CD4+ FoxP3+ cells after either treatment. AIl the glomerular lesions in both herbal medicine group and prednisone group were significantly lower than those in the model group (P<0.05). AI was positively related with the proportion of CD4+IL-17+ cells (Spearman's rho= 0.4958, P＜0.05), but was negatively correlated with the proportions of CD4+Foxp3+ cells(Spearman's rho= -0.5934，P＜0.05) and CD4+CD25-FOXP3+ cells (Spearman's rho= -0.5914，P＜0.05).Conclusion: Both Chinese herbal medicine and prednisone significantly enhanced the proportion of CD4+CD25-FOXP3+ cells and reduced the proportion of Th17 cells in lupus-prone MRL/lpr mice. Increased proportion of CD4+CD25-FOXP3+ cells was correlated with less severe glomerular lesions, indicating that CD4+CD25-FOXP3+ cells might play a regulatory role in the treatment of systemic lupus erythematosus.Keywords: Systemic lupus erythematosus; regulatory T cells; Herbal medicine; Prednison

Patterns of Dynamical Gauge Symmetry Breaking

We construct and analyze theories with a gauge symmetry in the ultraviolet of the form $G \otimes G_b$, in which the vectorial, asymptotically free $G_b$ gauge interaction becomes strongly coupled at a scale where the $G$ interaction is weakly coupled and produces bilinear fermion condensates that dynamically break the $G$ symmetry. Comparisons are given between Higgs and dynamical symmetry breaking mechanisms for various models.Comment: 14 pages, late

Distinct transport behaviors of LaFe1-yCoyAsO1-xFx (x=0.11) between the superconducting and nonsuperconducting metallic y regions divided by y ~ 0.05

Electrical resistivities, Hall coefficients and thermoelectric powers have been measured for polycrystalline samples of LaFe1-yCoyAsO1-xFx (x=0.11) with various values of y. The results show that there exists clear distinction of these transport behaviors between the superconducting and nonsuperconducting metallic regions of y divided by the boundary value yc~0.05. We have found that the behaviors in both regions are very similar to those of high-Tc Cu oxides in the corresponding phases. If they reflect, as in the case of Cu oxides, effects of strong magnetic fluctuations, the energy scale of the fluctuations is considered to be smaller than that of the high Cu oxides by a factor of ~1/2. Arguments on the electronic nature and superconducting symmetry are presented on the basis of the observed small rate of the Tc suppression rate by the Co doping.Comment: 8 pages, 4 figures, submitted to J. Phys. Soc. Jp

Progress towards elimination of mother-to-child transmission of hepatitis B virus infection in China: a modelling analysis.

Objective: To determine the projected burden of hepatitis B virus (HBV) in China, the intervention strategies that can eliminate mother-to-child transmission (MTCT) by 2030 or earlier and the measurable parameters that can be used to monitor progress towards this target. Methods: We developed a dynamic, sex- and age-stratified model of the HBV epidemic in China, calibrated using hepatitis B surface antigen (HBsAg) and e antigen (HBeAg) prevalence data from sequential national serosurveys (1979-2014) and the numbers of HBV-related cancer deaths (2012). We determined whether China can achieve elimination of MTCT of HBV by 2030 under current prevention interventions. We modelled various intervention scenarios to represent different coverage levels of birth-dose HBV vaccination, hepatitis B immunoglobulin to newborns of HBsAg-positive mothers and antiviral therapy (tenofovir) to HBeAg-positive pregnant women. Findings: We project that, if current levels of prevention interventions are maintained, China will achieve the elimination target by 2029. By modelling various intervention scenarios, we found that this can be brought forward to 2025 by increasing coverage of birth-dose vaccination, or to 2024 by the administration of tenofovir to HBeAg-positive pregnant women. We found that achievement of the target by 2025 would be predicted by a measurement of less than 2% MTCT in 2020. Conclusion: Our results highlight how high-quality national data can be combined with modelling in monitoring the elimination of MTCT of HBV. By demonstrating the impact of increased interventions on target achievement dates, we anticipate that other high-burden countries will be motivated to strengthen HBV prevention policies

Microstructure and properties of Mg-Nd-Zn-Zr alloys

One of the limitations of magnesium alloys is their low mechanical properties at elevated temperatures. In order to improve the creep strength, rare earth element neodymium Nd is added to Mg-0.3Zn-0.32Zr alloy. A significant grain refinement has already been achieved by the Zr addition in the base metal. The inclusion of Nd further reduces grain size from 120 μm to 75 μm. When the Nd content is less than 1%, the Nd is fully dissolved into Mg matrix. Increasing the Nd addition to 1.6% leads to a precipitation of Mg 12Nd intermetallic phase at grain boundaries. The Nd-contained materials undergo a T6 heat treatment with a solution treatment at 530°C for 8 hours followed by an aging at 250°C for 12 hours. The heat treatment results in the Nd fully dissolved and then re-precipitated as Mg12Nd, distributing as cluster within the grains and along the grain boundaries. This Mg12Nd precipitation significantly increases the mechanical properties of the materials, especially the high temperature properties. The 200°C tensile strength is 120 MPa for 0.2% Nd-contained alloy and 200 MPa at 2.6% Nd. Even at a higher temperature, 300°C, the Nd-contained alloys still retain significant strength, 60MPa for 0.2% Nd alloy and 110 MPa for 2.6% Nd alloy. The heat treatment also results in some grain coarsening, and Nd acts as effective barriers for the grain agglomeration