Guinea pig and rabbit aortic rings which have been incubated in a Ca2+- and Mg2+ -free solution containing ethylene glycol bis-(beta-aminoethyl ether) N,N,N'N'-tetraacetic acid (EGTA) responded to addition of Ca2+ in a similar Ca2+ - and Mg2+ -free solution without EGTA by increasing tension gradually at first and then more sharply at Ca2+ concentrations above 2 mM. Prior addition of D 600 (10 or 50 microM) inhibited contractions to low Ca2+ concentrations, but only partially attenuated those to high Ca2+ concentrations. The resulting contraction is thought to represent Ca2+ entry from both voltage-dependent (D 600-sensitive) Ca2+ channels and Na+ -Ca2+ exchange (D 600-insensitive).
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http://dx.doi.org/10.1016/0014-2999(86)90503-0 | DOI Listing |
Environ Toxicol Chem
January 2025
ARCHE Consulting, Ghent, Belgium.
This study aimed to develop a bioavailability-based effects assessment method for nickel (Ni) to derive acute freshwater environmental thresholds in Europe. The authors established a reliable acute freshwater Ni ecotoxicity database covering 63 different freshwater species, and the existing acute Ni bioavailability models for invertebrates were revised. A single average invertebrate bioavailability model was proposed, in which the protective effects of Ca2+ and Mg2+ on Ni2+ toxicity were integrated as a single-site competition effect at the Ni biotic ligand.
View Article and Find Full Text PDFUnlabelled: One of the principles of prevention and non-drug treatment of liver diseases, including hepatitis of various etiologies, is the normalization of the diet, including the use of daily diet foods with physiologically active ingredients, in particular betulin, which helps to reduce metabolic and oxidative processes within liver cells. The aim of the work was to evaluate the in vivo effect of triterpene alcohol betulin Roth isolated from the bark of birch Betula pendula Roth. added to fat-containing products (for example, mayonnaise) on the biochemical parameters of blood and the morphological structure of the liver of rats with initiated acute toxic hepatitis.
View Article and Find Full Text PDFSmall
January 2025
Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai, 980-8577, Japan.
Hollandite-type α-MnO exhibits exceptional promise in current industrial applications and in advancing next-generation green energy technologies, such as multivalent (Mg, Ca, and Zn) ion battery cathodes and aerobic oxidation catalysts. Considering the slow diffusion of multivalent cations within α-MnO tunnels and the catalytic activity at edge surfaces, ultrasmall α-MnO particles with a lower aspect ratio are expected to unlock the full potential. In this study, ultrasmall α-MnO (<10 nm) with a low aspect ratio (c/a ≈ 2) is synthesized using a newly developed alcohol solution process.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
School of Chemistry and Molecular Engineering, East China Normal University, Dongchuan Road 500, Shanghai, 200241, China.
Monitoring dynamic neurochemical signals in the brain of free-moving animals remains great challenging in biocompatibility and direct implantation capability of current electrodes. Here we created a self-supporting polymer-based flexible microelectrode (rGPF) with sufficient bending stiffness for direct brain implantation without extra devices, but demonstrating low Young's modulus with remarkable biocompatibility and minimal position shifts. Meanwhile, screening by density functional theory (DFT) calculation, we designed and synthesized specific ligands targeting Mg and Ca, and constructed Mg-E and Ca-E sensors with high selectivity, good reversibility, and fast response time, successfully monitoring Mg and Ca in vivo up to 90 days.
View Article and Find Full Text PDFACS Nano
January 2025
National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, P. R. China.
Regeneration of diabetic bone defects remains a formidable challenge due to the chronic hyperglycemic state, which triggers the accumulation of advanced glycation end products (AGEs) and reactive oxygen species (ROS). To address this issue, we have engineered a bimetallic metal-organic framework-derived Mn@CoO@Pt nanoenzyme loaded with alendronate and Mg ions (termed MCPtA) to regulate the hyperglycemic microenvironment and recover the osteogenesis/osteoclast homeostasis. Notably, the Mn atom substitution in the CoO nanocrystalline structure could modulate the electronic structure and significantly improve the SOD/CAT catalytic activity for ROS scavenging.
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