Underlying formation pathways of dimethylmercury ((CH3)2Hg) in the ocean are unknown. Early work proposed reactions of inorganic Hg (Hg(II)) with methyl cobalamin or of dissolved monomethylmercury (CH3Hg) with hydrogen sulfide as possible bacterial mediated or abiotic pathways. A significant fraction (up to 90%) of CH3Hg in natural waters is however adsorbed to reduced sulfur groups on mineral or organic surfaces. We show that binding of CH3Hg to such reactive sites facilitates the formation of (CH3)2Hg by degradation of the adsorbed CH3Hg. We demonstrate that the reaction can be mediated by different sulfide minerals, as well as by dithiols suggesting that e.g. reduced sulfur groups on mineral particles or on protein surfaces could mediate the reaction. The observed fraction of CH3Hg methylated on sulfide mineral surfaces exceeded previously observed methylation rates of CH3Hg to (CH3)2Hg in seawaters and we suggest the pathway demonstrated here could account for much of the (CH3)2Hg found in the ocean.
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http://dx.doi.org/10.1038/srep27958 | DOI Listing |
Antioxid Redox Signal
January 2025
Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, NHC Key Laboratory of Assisted Circulation (Sun Yat-Sen University), The First Affiliated Hospital, Sun Yat Sen University, Guangzhou, China.
Abnormal migration and proliferation of vascular smooth muscle cells (VSMCs) are considered early events in the onset of thoracic aortic dissection (TAD). Endogenous sulfur dioxide (SO), primarily produced by aspartate aminotransferase (AAT1) in mammals, has been reported to inhibit the migration and proliferation of VSMCs. However, the role of SO in the development of TAD remains unclear.
View Article and Find Full Text PDFChem Mater
January 2025
Graduate School of Biomedical Science and Engineering, Koç University, Istanbul 34450, Türkiye.
AgBiS nanocrystals (NCs), composed of nontoxic, earth-abundant materials and exhibiting an exceptionally high absorption coefficient from visible to near-infrared (>10 cm), hold promise for photovoltaics but have lack of photoluminescence (PL) due to intrinsic nonradiative recombination and challenging shell growth. In this study, we reported a facile wet-chemical approach for the epitaxial growth of ZnS shell on AgBiS NCs, which triggered the observation of PL emission in the near-infrared (764 nm). Since high quality of the core is critical for epitaxial shell growth, we first obtained rock-salt structured AgBiS NCs with high crystallinity, nearly spherical shape and monodisperse size distribution (<6%) via a dual-ligand approach reacting Ag-Bi oleate with elemental sulfur in oleylamine.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
College of Materials Science and Engineering, Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials, Shaanxi University of Science and Technology, Xian 710021, China.
The low conductivity of sulfur substances and the fussy effect of lithium polysulfides (LPS) limit the practical application of lithium-sulfur batteries (LSBs). In this work, NiS is in situ synthesized on N-doped 3D carbon nanofibers with an optimized pore structure as a cathode material for LSBs. The conductive carbon nanofiber skeleton with a hierarchical (micropore-mesopore-macropore) structure etched by Cd can reduce the interface resistance of the cathode and remiss volume expansion during charge-discharge progress.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Crop Science, Chungbuk National University, Cheongju-si, 28644, Republic of Korea.
Glyphosate (Gly) is a widely used herbicide for weed control in agriculture, but it can also adversely affect crops by impairing growth, reducing yield, and disrupting nutrient uptake, while inducing toxicity. Therefore, adopting integrated eco-friendly approaches and understanding the mechanisms of glyphosate tolerance in plants is crucial, as these areas remain underexplored. This study provides proteome insights into Si-mediated improvement of Gly-toxicity tolerance in Brassica napus.
View Article and Find Full Text PDFJ Food Sci
January 2025
Key Laboratory of Agro-food Quality and Safety of Ministry of Agriculture and Rural Affairs, Institute of Agricultural Quality Standard and Testing Technology, Chinese Academy of Agricultural Sciences, Beijing, China.
This study applied program temperature-controlled drying (PTCD) to optimize the hot-air drying process for shiitake mushrooms, adjusting the drying temperature based on activity changes of γ-glutamyl transpeptidase (γ-GTase) and cysteine sulfoxide lyase (C-S lyase). Compared with constant temperature drying, PTCD (ST_75 and ST_150) significantly enhanced the umami and aroma profiles and sulfur compounds, increasing the levels of key flavor compounds such as glutamic acid and 5'-GMP. Moreover, PTCD improved rehydration capacity (515.
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