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A large database for α-hexachlorocyclohexane (α-HCH), together with multimedia models, shows this chemical to have exhibited classical ‘cold condensation’ behavior. The surface water of the Arctic Ocean became loaded between 1950 and 1990 because atmospheric transport of α-HCH from source regions to the Arctic was rapid and because α-HCH partitioned strongly into cold water there. Following emission reductions during the 1980s, α-HCH remained trapped under the permanent ice pack, with the result that the highest oceanic concentrations in the early 1990s were to be found in surface waters of the Canada Basin. Despite a much stronger partitioning into water than for α-HCH, β-HCH did not accumulate under the pack ice of the Arctic Ocean, as might be expected from the similar emission histories for the two chemicals. β-HCH appears to have loaded only weakly into the high Arctic through the atmosphere because it was rained out or partitioned into North Pacific surface water. However, β-HCH has subsequently entered the western Arctic in ocean currents passing through Bering Strait. β-HCH provides an important lesson that environmental pathways must be comprehensively understood before attempting to predict the behavior of one chemical by extrapolation from a seemingly similar chemical. [Copyright &y& Elsevier]

The circular susceptibility χ of amorphous and nanocrystalline Fe73.5Cu1Nb3Si13.5B9 wires was measured under an axially applied field H up to 89 kA/m. The χ(H) of the amorphous sample may be well described by the core–shell model of positive magnetostrictive amorphous wires; however, after nanocrystallization, the χ(H) can be a few to few tens times greater than the ideal circular susceptibility χid=Ms/H deduced from the assumption of a zero anisotropy. This phenomenon is discussed in terms of a negative local anisotropy field Hk* resulting from the existence of magnetic inclusions, but its actual mechanism has to be further studied. [Copyright &y& Elsevier]

β-SiC nanoparticles (NPs) were anchored onto the surface of reduced graphene oxide (RGO) by a facile solvothermal method. The characterization results of the novel RGO-SiC composites indicate an effective chemical interaction between the RGO sheets and β-SiC NPs. Moreover, methylene blue (MB) dye was employed as a model pollutant to evaluate the adsorption and photocatalytic ability of the composites. It is found that the content of RGO sheets can significantly tune the adsorption and photocatalytic activity of various composites with an optimal value of 3 wt%. The enhancement of photocatalytic activity can be attributed to the synergistic effect of the accelerated separation of photogenerated electron-hole pairs, and the enhanced absorption ability for dyes is mainly due to the RGO sheets which work as an excellent photocatalyst supporter and offer electrons channel to accept and transfer the photogenerated carriers from excited β-SiC NPs. [ABSTRACT FROM AUTHOR]

Background: In this study, we assessed the prognostic value of the lymph node ratio (LNR), established a hypothetical tumor–ratio–metastasis (TRM) staging system and compared it with the 7th edition International Union Against Cancer pathological N (pN) and tumor–node–metastasis (TNM) system.Patients and methods: A total of 1343 gastric cancer patients undergoing D2 resection were staged using the TRM staging system and the 7th edition TNM system. Optimal cut points of LNR were calculated using X-tile software and validated by bootstrapping. Homogeneity, discriminatory ability, and monotonicity of gradients of the TRM and TNM systems were compared using linear trend χ2, likelihood ratio χ2 statistics, and Akaike information criterion (AIC) calculations.Results: Optimal cut points classified patients into LNR0 (0%), LNR1 (1%–30%), LNR2 (31%–60%), and LNR3 (61%–100%) groups. In univariate, multivariate and stratified analyses, the LNR staging showed superiority to the 7th edition pN staging. The TRM staging system had higher linear trend and likelihood ratio χ2 scores and smaller AIC values compared with those for the TNM system, which represented the optimum prognostic stratification.Conclusions: The novel TRM staging system predicts survival of gastric cancer more accurately than the 7th edition TNM system. It may be considered as an alternative to TNM system. [ABSTRACT FROM AUTHOR]