327 research outputs found

    Gender Equity in Chinese Education

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    Valley Contrasting Magnetoluminescence in Monolayer MoS2_{2} Quantum Hall Systems

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    The valley dependent optical selection rules in recently discovered monolayer group-VI transition metal dichalcogenides (TMDs) make possible optical control of valley polarization, a crucial step towards valleytronic applications. However, in presence of Landaul level(LL) quantization such selection rules are taken over by selection rules between the LLs, which are not necessarily valley contrasting. Using MoS2_{2} as an example we show that the spatial inversion-symmetry breaking results in unusual valley dependent inter-LL selection rules, which directly locks polarization to valley. We find a systematic valley splitting for all Landau levels (LLs) in the quantum Hall regime, whose magnitude is linearly proportional to the magnetic field and in comparable with the LL spacing. Consequently, unique plateau structures are found in the optical Hall conductivity, which can be measured by the magneto-optical Faraday rotations

    Carbon Stocks of Coarse Woody Debris in Central African Tropical Forests

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    Coarse Woody Debris (CWD; defined here as fallen and standing dead trees and tree branches) is a critical-structural and functional component of forest ecosystems that typically comprises a large proportion of total aboveground carbon storage. Coarse woody debris estimation for the tropics is uncommon, and little is known about how carbon storage in CWD will respond to climate change. Given the predominant role that tropical forests play in global carbon cycling, this information gap compromises efforts to forecast climate change impacts on terrestrial carbon balance. In this study, we aimed to identify the variation in Coarse Woody Debris (CWD) stocks between forest types (Old-growth and selective logging forests) and among the plots in Ipendja mixed lowland terra firme tropical rainforest (central Africa), and we examined the consequence for CWD carbon stocks estimation. The study area is located at Ipendja forest management unit (UFA), close to Dongou district (Likouala Department), in Northern Republic of Congo. Data collection were done with eight rectangular plots, each 25 x 200 m (0.5 ha). The method of line intercepts sampling has been used in each studied site. A total number of 135 CWD samples of diameter Âł 10 cm in the studied plots have been recorded. It was obvious that stock of coarse woody debris in Mokelimwaekili site (mean: 19.96 Mg ha-1; sum: 79.84 Mg ha-1) were higher than those of Sombo site (mean: 8.9 Mg ha-1; sum: 35 Mg ha-1). There was a significance difference in Ipendja evergreen forest about CWD stocks across two forest types and plots. This finding suggests that values vary among forest types and that separate reference values should be adopted for estimates of undisturbed forest carbon stocks in the different ecosystems in Congo basin. Different reference values represent the variability of CWD among forest types and contribute to reducing uncertainties in current estimates of carbon stock in central African forest ecosystems

    IL28B is associated with outcomes of chronic HBV infection

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    Purpose The role of IL28B gene variants and expression in hepatitis B virus (HBV) infections are not well understood. Here, we evaluated whether IL28B gene expression and rs12979860 variations are associated with HBV outcomes. Materials and Methods IL28B genetic variations (rs12979860) were genotyped by pyrosequencing of DNA samples from 137 individuals with chronic HBV infection [50 inactive carriers (IC), 34 chronic hepatitis B (CHB), 27 cirrhosis, 26 hepatocellular carcinoma (HCC)], and 19 healthy controls. IL28A/B mRNA expression in peripheral blood mononuclear cells was determined by qRT-PCR, and serum IL28B protein was measured by ELISA. Results Patients with IL28B C/C genotype had greater IL28A/B mRNA expression and higher IL28B protein levels than C/T patients. Within the various disease stages, compared to IC and healthy controls, IL28B expression was reduced in the CHB, cirrhosis, and HCC cohorts (CHB vs. IC, p=0.02; cirrhosis vs. IC, p=0.01; HCC vs. IC, p=0.001; CHB vs. controls, p&#60;0.01; cirrhosis vs. controls, p&#60;0.01; HCC vs. controls, p&#60;0.01). When stratified with respect to serum HBV markers in the IC and CHB cohorts, IL28B mRNA and protein levels were higher in HBeAg-positive than negative individuals (p=0.01). Logistic regression analysis revealed that factors associated with high IL28B protein levels were C/C versus C/T genotype [p=0.016, odds ratio (OR)=0.25, 95% confidence interval (CI)=0.08-0.78], high alanine aminotransferase values (p&#60;0.001, OR=8.02, 95% CI=2.64-24.4), and the IC stage of HBV infection (p&#60;0.001). Conclusion Our data suggest that IL28B genetic variations may play an important role in long-term development of disease in chronic HBV infections.</p

    Tobacco Mosaic Virus Templated Synthesis of One Dimensional Inorganic–Polymer Hybrid Fibres

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    Inorganic–polymer hybrid nanofibres were prepared by using a rod-like tobacco mosaic virus (TMV) as a template. With tetraethylorthosilicate (TEOS) as a precursor, long silica-coated TMVfibres were formed via a head-to-tail assembly, which showed a substantial increase of the elastic modulus. Furthermore, homogenous titania–TMV hybrid fibres could be prepared using polyaniline-coated TMV fibres as a template, which were used to form a composite film that was able to sense liquefied petroleum gases

    Tobacco Mosaic Virus Templated Synthesis of One Dimensional Inorganic-Polymer Hybrid Fibres

    Get PDF
    Inorganic–polymer hybrid nanofibres were prepared by using a rod-like tobacco mosaic virus (TMV) as a template. With tetraethylorthosilicate (TEOS) as a precursor, long silica-coated TMVfibres were formed via a head-to-tail assembly, which showed a substantial increase of the elastic modulus. Furthermore, homogenous titania–TMV hybrid fibres could be prepared using polyaniline-coated TMV fibres as a template, which were used to form a composite film that was able to sense liquefied petroleum gases
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