Ice sheets play a more important role in the global silicon cycle than previously appreciated. Input of dissolved and amorphous particulate silica into natural waters stimulates the growth of diatoms. Here we measure dissolved and amorphous silica in Greenland Ice Sheet meltwaters and icebergs, demonstrating the potential for high ice sheet export. Our dissolved and amorphous silica flux is 0.20 (0.06-0.79) Tmol year, ∼50% of the input from Arctic rivers. Amorphous silica comprises >95% of this flux and is highly soluble in sea water, as indicated by a significant increase in dissolved silica across a fjord salinity gradient. Retreating palaeo ice sheets were therefore likely responsible for high dissolved and amorphous silica fluxes into the ocean during the last deglaciation, reaching values of ∼5.5 Tmol year, similar to the estimated export from palaeo rivers. These elevated silica fluxes may explain high diatom productivity observed during the last glacial-interglacial period.
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http://dx.doi.org/10.1038/ncomms14198 | DOI Listing |
Inorg Chem
January 2025
Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan.
Bismuth oxide nanosheets were synthesized through the exfoliation of layered compounds without any organic exfoliation agents. The layered compound BiSrCaFeO, comprising Bi-O layers and Sr-Ca-Fe-O layers, was synthesized as the starting material. The Sr-Ca-Fe-O layers were selectively dissolved by shaking the compound in 0.
View Article and Find Full Text PDFPharmaceutics
December 2024
University of Belgrade-Faculty of Chemistry, Studentski trg 12-16, 11000 Belgrade, Serbia.
Background/objectives: Clofazimine (CFZ) is a Biopharmaceutics Classification System (BCS) II drug introduced in the US market in 1986 for the treatment of leprosy. However, CFZ was later withdrawn from the market due to its extremely low aqueous solubility and low absorption. In the literature, the intrinsic solubility of CFZ has been estimated to be <0.
View Article and Find Full Text PDFEnviron Res
December 2024
College of Land Science and Technology, China Agricultural University, Beijing, 100193, PR China; Key Laboratory of Arable Land Conservation in North China, Ministry of Agriculture and Rural Affairs, Beijing, 100193, PR China. Electronic address:
The ongoing weathering of metal sulfides has substantially posed threats to the eco-systems. For remediating metal sulfides-contaminated soils, phytostabilization is a promising nature-based technique that immobilizing heavy metals (HMs) that dissolved from metal sulfides in the rhizosphere, preventing their leaching and migrating into soil and groundwater. However, the underlying mechanism regarding the mineral-root interaction involving primary metal sulfides such as galena (PbS) during the remediation processes has yet been well studied.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Material Science, BASF SE, RGA/BM-B007, Carl-Bosch-Str. 38, D-67056 Ludwigshafen, Germany.
The controlled formation and stabilization of nanoparticles is of fundamental relevance for materials science and key to many modern technologies. Common synthetic strategies to arrest growth at small sizes and prevent undesired particle agglomeration often rely on the use of organic additives and require non-aqueous media and/or high temperatures, all of which appear critical with respect to production costs, safety, and sustainability. In the present work, we demonstrate a simple one-pot process in water under ambient conditions that can produce particles of various transition metal carbonates and sulfides with sizes of only a few nanometers embedded in a silica shell, similar to particles derived from more elaborate synthesis routes, like the sol-gel process.
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