Spectrophotometry was used to study the effect of EDTA on plutonium oxidation state distribution as a function of time, pH, and ligand-to-metal ratio (L/M) under anoxic conditions. Novel Pu(V)-EDTA absorption bands were identified at 571, 993, 1105, and 1150 nm with molar absorption coefficients of 15 ± 1, 6 ± 1, 10 ± 1, and 10 ± 1 cmM, respectively. Pu(V)-EDTA spectral changes occurred at L/M < 1, indicating only PuO(EDTA) formed with logK = 3.6 ± 0.3. Time-resolved experiments showed EDTA drastically increased the Pu(V/VI) reduction rate, which we propose is driven by amine lone-pair electron donation and the oxidative decarboxylation of EDTA. Oxidation of Pu(III)-EDTA to Pu(IV)-EDTA occurred on a slower time scale (110-237 days) than previously reported (<15 min) and is hypothesized to be radiolysis driven. Pu(V/VI)-EDTA and Pu(III)-EDTA both approached Pu(IV)-EDTA stabilization over time, yet Pu(V/VI)-EDTA solubility data was ≥ 1.0 log units higher than predicted by Pu(IV)-EDTA solubility models, indicating that current thermodynamic models are incomplete. Ultimately, the data show EDTA preferentially stabilizes Pu(IV) over time regardless of initial oxidation state, but Pu(V)-EDTA can persist under environmentally-relevant conditions, emphasizing the need to continue investigating redox reactions, speciation, and behavior of these complexes to support the transuranic waste disposal and surface remediation/containment efforts.
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http://dx.doi.org/10.1016/j.chemosphere.2021.129741 | DOI Listing |
Ecotoxicol Environ Saf
January 2025
State Key Laboratory of Swine and Poultry Breeding Industry, Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chendu 611130, PR China. Electronic address:
Copper is an essential trace element in biological systems, playing a key role in various physiological functions, including redox reactions and energy metabolism. However, an imbalance in copper homeostasis can induce oxidative stress, mitochondrial dysfunction, and inhibition of the ubiquitin-proteasome system, ultimately leading to significant cytotoxicity and cell death. According to recent research, copper can bind to lipoylation sites on proteins involved in the tricarboxylic acid cycle, causing aggregation of lipoylated proteins, the loss of Fe-S cluster proteins, proteotoxic stress, and ultimately, cell death.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction, Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan 430079, P. R. China.
-cycloalkenes are abundant in bioactive natural products and have been used as powerful tools in chemical biology and drug discovery. However, strategies for the modular synthesis of -cycloalkenes, especially planar-chiral medium-sized ones, with high efficiency and selectivity, still remain elusive. Herein, we report a Pd-catalyzed asymmetric [7 + 2] cyclization strategy to address this challenge.
View Article and Find Full Text PDFPLoS One
January 2025
College of Physics and Electronic Engineering, Hainan Normal University, HaiKou, China.
We have successfully prepared a significant number of nanowires from non-toxic silicon sources. Compared to the SiO silicon source used in most other articles, our preparation method is much safer. It provides a simple and harmless new preparation method for the preparation of silicon nanowires.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
NO is a significant primary atmospheric pollutant that plays a key role in atmospheric chemistry. It serves as a crucial precursor to photochemical smog, acid rain, and secondary particulate matter and is instrumental in determining the atmospheric oxidation capacity. In this review, we focus on the heterogeneous chemistry of NO, which has been demonstrated to significantly influence the sources and sinks of various nitrogen-containing species through field measurements and model simulations.
View Article and Find Full Text PDFAnal Chem
January 2025
State Key Laboratory of Applied Organic Chemistry and Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Gansu Lanzhou 730000, China.
The pathogenesis of acute kidney injury (AKI) is a multifaceted process involving various mechanisms, with oxidative stress playing a crucial role in its development. Hypochlorite (HOCl) and cysteine (Cys) are indicators of oxidative stress in AKI pathophysiology, directly reflecting the degree of oxidative stress and disease severity. However, their exact mechanism of action in AKI pathophysiology remains unknown.
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