A simple, rapid and economic method has been developed for the reduction of potassium permanganate in alkaline carbonate uranium leach liquors to a colourless solution. The pink colour of permanganate, if not reduced, seriously impedes the determination of carbonate, bicarbonate and phosphate by titrimetry and spectrophotometry. Out of 17 reductants investigated, commercial sugar has been found to be the most effective, rapid, simple and interference free for further estimations. To the best of the authors' knowledge, this is the first time that sugar as a reductant has been made use of in analytical investigations.
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http://dx.doi.org/10.1016/0039-9140(95)01530-o | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125.
Microbial metabolism is impressively flexible, enabling growth even when available nutrients differ greatly from biomass in redox state. , for example, rearranges its physiology to grow on reduced and oxidized carbon sources through several forms of fermentation and respiration. To understand the limits on and evolutionary consequences of this metabolic flexibility, we developed a coarse-grained mathematical framework coupling redox chemistry with principles of cellular resource allocation.
View Article and Find Full Text PDFChron Respir Dis
January 2025
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
A 57-year-old female presented with a chief complaint of cough, with productive yellow sputum particularly severe in the morning. Bronchoscopy revealed inflammatory changes in both main bronchi, with abundant white purulent secretions and necrotic material adhering to the luminal surface. Histopathological examination showed chronic inflammatory changes in the mucosal tissue, with mild hyperplasia of the local squamous epithelium and evidence of keratinization in the surrounding area, consistent with a diagnosis of tracheal mucosal keratosis.
View Article and Find Full Text PDFPLoS One
January 2025
Colección Nacional de Crustáceos, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico, Ciudad de México, Mexico.
The analysis of carbon and nitrogen stable isotopes (δ13C and δ15N) has been widely used in ecology since it allows to identify the circulation of energy in a trophic network. The anchialine ecosystem is one of the less explored aquatic ecosystems in the world and stable isotope analysis represents a useful tool to identify the routes through which energy flows and to define the trophic niches of species. Sampling and data recording was conducted in one anchialine cave, Cenote Vaca Ha, near the town of Tulum, Quintana Roo, Mexico, where seven stygobitic species endemic to the anchialine caves of the Yucatan Peninsula, plus sediment, water and vegetation samples were analyzed to determine what the main nutrient sources are.
View Article and Find Full Text PDFArch Toxicol
January 2025
School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi, 530004, People's Republic of China.
Over the past decade, fentanyl-type new psychoactive substances (F-NPS) have emerged as the most representative synthetic opioids in third-generation drugs. These substances are characterized by their "low" fatal dose and parent drug levels in biological matrices, "fast" rates of derivatization and metabolism, and "many" derivatization sites and analogs. The low levels of parent fentanyl NPS in biological matrices complicate their detection, necessitating the use of characteristic metabolites as biomarkers for forensic analysis.
View Article and Find Full Text PDFEnviron Monit Assess
January 2025
Institute of Nuclear Physics Polish Academy of Sciences, Radzikowskiego 152, Krakow, PL-31342, Poland.
This study assessed the geogenic radon potential using PECAME, an innovative tool designed to simultaneously measure soil-gas permeability and CO concentration - two key parameters for understanding radon transport in soil. Comparative field studies using the RADON-JOK device in various geological settings in Japan and Poland demonstrate the effectiveness of PECAME. These studies reveal a strong correlation between PECAME and RADON-JOK, with an R value of 0.
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