Ambipolar Nernst effect in NbSe2_2

The first study of Nernst effect in NbSe$_2$ reveals a large quasi-particle contribution with a magnitude comparable and a sign opposite to the vortex signal. Comparing the effect of the Charge Density Wave(CDW) transition on Hall and Nernst coefficients, we argue that this large Nernst signal originates from the thermally-induced counterflow of electrons and holes and indicates a drastic change in the electron scattering rate in the CDW state. The results provide new input for the debate on the origin of the anomalous Nernst signal in high-T$_c$ cuprates.Comment: 5 pages including 4 figure

Electronic structure of one-dimensional copper oxide chains in LiCu2O2 from angle-resolved photoemission and optical spectroscopy

Angle-resolved photoemission (ARPES) and optical measurements were performed on single crystal samples of LiCu2O2, an antiferromagnetic S=1/2 spin-chain compound. The ARPES spectra show several dispersive branches associated with hybrid copper-oxygen states. The occurrence of the valence band maximum halfway between the center and the edge of the Brillouin zone, and the complex spectral line shapes are not reproduced by the existing calculations of the electronic structure. We suggest that they can be interpreted within a one-dimensional scenario of strongly correlated antiferromagnetic insulators. The combination of ARPES and optics allows us to estimate the magnitude of the charge-transfer gap (Delta=1.95 eV). Moreover, the temperature-dependent optical conductivity bears signatures of the three different magnetic phases of this material

Racial/ethnic differences in hepatic steatosis in a population‐based cohort of post‐menopausal women: the Michigan Study of Women's Health Across the Nation

Aims The prevalence of hepatic steatosis may differ between post‐menopausal African‐American women and non‐Hispanic white women and by sex hormone binding globulin level. We examined prevalence of hepatic steatosis by race/ethnicity and associations with sex hormone binding globulin. Methods Participants included post‐menopausal women who underwent hepatic ultrasound ( n  = 345) at the Michigan site of the Study of Women's Health Across the Nation, a population‐based study. We examined hepatic steatosis prevalence by race/ethnicity and used logistic regression models to calculate the odds of hepatic steatosis with race/ethnicity and sex hormone binding globulin, after adjustment for age, alcohol use, waist circumference, high density lipoprotein cholesterol, triglycerides, systolic blood pressure and use of medications reported to lower intrahepatic fat. Results Fewer African‐American women than non‐Hispanic white women had hepatic steatosis (23 vs. 36%, P  = 0.01). African‐American women had lower triglyceride and low‐density lipoprotein cholesterol levels, but higher blood pressure and follicle‐stimulating hormone levels ( P  < 0.05). In the optimal‐fitting multivariable models, women in the highest tertile of sex hormone binding globulin (60.2–220.3 nmol/l) had a lower odds of hepatic steatosis (odds ratio 0.43, 95% CI 0.20–0.93) compared with women in the lowest tertile of sex hormone binding globulin (10.5–40.3 nmol/l). There was an interaction between race/ethnicity and medication use whereby non‐Hispanic white women using medications had three times higher odds of hepatic steatosis compared with African‐American women not using medications (odds ratio 3.36, 95%  CI 1.07–10.58). Interactions between race/ethnicity and other variables, including sex hormone levels, were not significant. Conclusions Hepatic steatosis on ultrasound may be more common in post‐menopausal non‐Hispanic white women than African‐American women and was associated with lower levels of sex hormone binding globulin. What's new? Although hepatic steatosis is common in post‐menopausal women, previous studies have not examined risk factors in this population, particularly sex steroids and sex hormone binding globulin. We report that increased sex hormone binding globulin, the primary binding protein of sex hormones and a risk factor for diabetes, was strongly associated with decreased odds of hepatic steatosis in both race/ethnicities.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/101792/1/dme12225.pd

Effect of shot peening on the residual stress and mechanical behaviour of low-temperature and high-temperature annealed martensitic gear steel 18CrNiMo7-6

A martensitic gear steel (18CrNiMo7-6) was annealed at 180 \ub0C for 2h and at ∼ 750 \ub0C for 1h to design two different starting microstructures for shot peening. One maintains the original as-transformed martensite while the other contains irregular-shaped sorbite together with ferrite. These two materials were shot peened using two different peening conditions. The softer sorbite + ferrite microstructure was shot peened using 0.6 mm conditioned cut steel shots at an average speed of 25 m/s in a conventional shot peening machine, while the harder tempered martensite steel was shot peened using 1.5 mm steel shots at a speed of 50 m/s in an in-house developed shot peening machine. The shot speeds in the conventional shot peening machine were measured using an in-house lidar set-up. The microstructure of each sample was characterized by optical and scanning electron microscopy, and the mechanical properties examined by microhardness and tensile testing. The residual stresses were measured using an Xstress 3000 G2R diffractometer equipped with a Cr Kα x-ray source. The correspondence between the residual stress profile and the gradient structure produced by shot peening, and the relationship between the microstructure and strength, are analyzed and discussed

Doping nature of native defects in 1T−TiSe₂

The transition-metal dichalcogenide 1T−TiSe₂is a quasi-two-dimensional layered material with a charge density wave (CDW) transition temperature of TCDW≈200  K. Self-doping effects for crystals grown at different temperatures introduce structural defects, modify the temperature-dependent resistivity, and strongly perturbate the CDW phase. Here, we study the structural and doping nature of such native defects combining scanning tunneling microscopy or spectroscopy and ab initio calculations. The dominant native single atom dopants we identify in our single crystals are intercalated Ti atoms, Se vacancies, and Se substitutions by residual iodine and oxygen

Pilot study on the prevalence of salmonella in slaughter pigs in Germany: III. Detection of salmonellae by PCR, serovar distribution and population analysis of isolates

In a survey on the prevalence of Salmonellae in German slaughter pigs, almost 12,000 pig carcasses were investigated by standard cultural, immunological and PCR technique\u27s. Seven abattoirs distributed all over Germany were included into the study. Each abattoir was investigated on ten weekly sampling occasions. In total 6% of all slaughter pigs were positive in faecal or lymphnode material. This number increased to I 0% when surface swabs were evaluated as well. From all sources nearly 1400 bacterial isolates were obtained and characterised by traditional and molecular typing methods. Typing at the National Reference Laboratory for Salmonella (NRL) follows a hierarchic protocol. At the beginning the serotype is determined by using poly- and monoclonal antisera for standard slide agglutination. In total 28 serotypes could be detected