The fungi Aureobasidium pullulans , Mortierella humilis , Trichoderma harzianum and Phoma glomerata were used to investigate the formation of selenium- and tellurium-containing nanoparticles during growth on selenium- and tellurium-containing media. Most organisms were able to grow on both selenium- and tellurium-containing media at concentrations of 1 mM resulting in extensive precipitation of elemental selenium and tellurium on fungal surfaces as observed by the red and black colour changes. Red or black deposits were confirmed as elemental selenium and tellurium, respectively. Selenium oxide and tellurium oxide were also found after growth of Trichoderma harzianum with 1 mM selenite and tellurite as well as the formation of elemental selenium and tellurium. The hyphal matrix provided nucleation sites for metalloid deposition with extracellular protein and extracellular polymeric substances localizing the resultant Se or Te nanoparticles. These findings are relevant to remedial treatments for selenium and tellurium and to novel approaches for selenium and tellurium biorecovery.

Simultaneous stimulation of arsenic methylation and inhibition of cadmium bioaccumulation in rice grain using zero valent iron and alternate wetting and drying water management,

Epidemiologic studies report cardiovascular protection conferred by omega-3 fatty acids, in particular docosahexaenoic acid (DHA). However, few experimental studies have addressed its potential in acute stroke treatment. The present study used multimodal MRI to assess in vivo the neuroprotection conferred by DHA and by a brain-targeting form of DHA-containing lysophosphatidylcholine (AceDoPC) in experimental stroke. Rats underwent intraluminal middle cerebral artery occlusion (MCAO) and were treated at reperfusion by intravenous injection of i) saline, ii) plasma from donor rats, iii) DHA or iv) AceDoPC, both solubilized in plasma. Twenty-four hours after reperfusion, animals underwent behavioral tests and were sacrificed. Multiparametric MRI (MRA, DWI, PWI, T2-WI) was performed at H0, during occlusion, and at H24, before sacrifice. Brain tissue was used for assay of F(2)-isoprostanes as lipid peroxidation markers. Initial lesion size and PWI/DWI mismatch were comparable in the four groups. Between H0 and H24, lesion size increased in the saline group (mean ± s.d.: +18% ± 20%), was stable in the plasma group (-3% ± 29%), and decreased in the DHA (-17% ± 15%, P=0.001 compared to saline) and AceDoPC (-34% ± 27%, P=0.001 compared to saline) groups. Neuroscores in the AceDoPC group tended to be lower than in the other groups (P=0.07). Treatments (pooled DHA and AceDoPC groups) significantly decreased lipid peroxidation as compared to controls (pooled saline and vehicle) (P=0.03). MRI-based assessment demonstrated the neuroprotective effect of DHA in the MCAO model. Results further highlighted the therapeutic potential of engineered brain-targeting forms of omega-3 fatty acids for acute stroke treatment.

Carboniferous coals of the Ayrshire Coalfield are enriched in selenium (Se) relative to average UK and world compositions, substituting for sulphur in pyrite. Greenburn surface mine coals are characterized by syngenetic concretionary pyrite (c. 15% total area), occurring as bedding-parallel banding, and later-formed (epigenetic) cross-cutting pyrite in cleats (c. 9% total area). In these, sulphur isotope compositions for both syngenetic and epigenetic pyrite include isotopically light and heavy variants, suggesting diagenetic and hydrothermal fluid formation. Late/post-Visean cleat-filling pyrite is enriched in Se (up to 266 ppm) compared to the earlier-formed material (Se up to 181 ppm).Anomalous Se may have been sourced from near-by sulphidic Dalradian metamorphic rocks. Initial Se sequestration is associated with syngenetic pyrite mineralization, absorbed from seawater and pore waters, with additional Se introduced from fluids mobilized during epigenetic pyrite formation. Cleats from local brittle fracturing provided channels for fluid flow and a locus for precipitation of comparatively high-Se pyrite. Permian dolerite intrusions may have provided an enrichment source and/or fluid distribution mechanism. The Se concentrations of the Greenburn coals relate to multi-stage mineralization, with cleat-filling pyrite showing the highest Se content, and highlight the potential for high Se in similarly altered and fractured coal deposits worldwide.Supplementary material: LA-ICP-MS maps for Fe, Se, Ag, As, Cu, Hg, Pb and Te for Greenburn coal samples from seams 9300 Lime and 6900 Burnfoot Bridge are available at https://doi.org/10.6084/m9.figshare.c.3967860