In an acid medium, nitrite diazotized with p-rosaniline and then coupled with 8-hydroxyquinoline in a weak alkaline medium produces azo compounds. The azo compounds produce a very sensitive polarographic wave at -0.70 V (versus the saturated calomel electrode). The height of the peak is linear with the concentration of nitrite in the range of 5 x 10(-9) to 5 x 10(-7) g/mL. The detection limit is 3 x 10(-9) g/mL. The electrochemical characteristics of the polarographic wave are also discussed. The method was used to determine nitrite in sausage. The results agree well with those obtained by spectrophotometry.
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J Am Chem Soc
March 2025
Department of Chemistry, The University of Hong Kong, Hong Kong 999077, SAR ,China.
Electrochemical H production from water favors low-voltage molecular oxidation to replace the oxygen evolution reaction as an energy-saving and value-added approach. However, there exists a mismatch between the high demand for H and slow anodic reactions, restricting practical applications of such hybrid systems. Here, we propose a bipolar H production approach, with anodic H generation from the N-N oxidatively coupled dehydrogenation (OCD) of 3,5-diamino-1-1,2,4-triazole (DAT), in addition to the cathodic H generation.
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August 2025
College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
In this study, layered chitosan-based magnetic nickel ferrite NiFeO/chitosan (CS-LDO) composites were synthesized. The results show that under optimal conditions, 98 % of methylene blue (MB) and 92 % of xylenol orange (XO) can be simultaneously degraded within 120 min in the CS-LDO/persulfate (PS) system, and the removal rates of total organic carbon (TOC) and chemical oxygen demand (COD) can reach 67.32 % and 74.
View Article and Find Full Text PDFGates Open Res
March 2025
Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK.
Background: The emergence of insecticide resistance in insects has led researchers to develop new control tools so that historic gains made in reducing disease transmission are not lost. Attractive targeted sugar baits (ATSBs) are a vector control tool being widely trialled to target insects that feed on plant sugars and blood. We designed a field-friendly, economical and more environmentally responsible sugar feeder for maintaining mosquito colonies and screening potential ATSB candidates.
View Article and Find Full Text PDFSci Rep
March 2025
Laboratory of Biology, Engineering and Imaging for Ophthalmology (BiiO), Faculty of Medicine, Health Innovation Campus, Jean Monnet University, Saint-Étienne, France.
This study addressed limitations in calcein-AM-based endothelial viability assays, specifically focusing on pre-stripped DMEK grafts. Key challenges included the suboptimal calcein staining and the incompatibility of the viability assay with subsequent immunofluorescence (IF). Using human corneal grafts, we employed two strategies to optimize calcein staining.
View Article and Find Full Text PDFPeerJ
March 2025
Avtsyn Research Institute of Human Morphology, Petrovsky National Research Centre of Surgery, Moscow, Russia.
Background: One of the effective strategies for the treatment of tumor diseases, including colitis-associated colorectal cancer (CAC), is immunotherapy. During inflammation, NF-κB is activated, which is connected with the hypoxia-inducible factor-HIF, regulating the immune cells functioning and influences the CAC development. Organisms differ according to their hypoxia resistance and HIF expression.
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