Studies have been carried out in a Goldmine in Ghana to determine the exposure of the public to naturally occurring radioactive materials from processing of gold ore. Direct gamma spectrometry and neutron activation analysis techniques were used to analyse soil, rock, water and dust samples from the mining environment. The mean activity concentrations measured for (238)U, (232)Th and (40)K in the soil/rock samples were 15.2, 26.9 and 157.1 Bq kg( - 1), respectively. For the water samples, the mean activity concentrations were 0.54 and 0.41 Bq l( - 1)) and 7.76 Bq l( - 1) for (226)Ra, (232)Th and (40)K, respectively. The mean activity concentrations measured in the dust samples were 4.90 and 2.75 μBq m( - 3) for (238)U and (232)Th, respectively. The total annual effective dose to the public was estimated to be 0.69 mSv. The results in this study compared well with typical world average values. The results indicate an insignificant exposure of the public from the activities of the Goldmine.
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http://dx.doi.org/10.1007/s10661-010-1769-9 | DOI Listing |
Microbiol Spectr
January 2025
Yunnan Provincial Key Laboratory of Animal Nutrition and Feed, Faculty of Animal Science and Technology, Yunnan Agricultural University, Kunming, China.
is a vital zoonotic pathogen known for its extensive drug resistance and ability to form biofilms, which contribute to its antibiotic resistance. In this study, the phage vB_C4, specifically targeting , was isolated and subjected to bioinformatic analysis and bacteriostatic activity assays. The combination of phage vB_C4 with antibiotics such as cephalothin and cefoxitin, which target the bacterial cell wall, resulted in a significantly enhanced bacteriostatic effect compared to either the phage or antibiotics alone.
View Article and Find Full Text PDFIn this study, we have designed and developed a cationic bolaform C12-(2,3-dihydroxy-N, N-dimethyl-N-(2-ureidoethyl)propan-1-aminium chloride)2 (C12(DDUPAC)2) that is derived from biocompatible molecules. The bolaform C12(DDUPAC)2 has hydroxyl (OH) functionality at both the cationic head groups. The impact of head group structure on the self-assembly and effectiveness of gene transfection and antimicrobial activity was investigated and compared with that of the hydrochloride salt C12-(N, N-dimethyl-N-(2-ureidoethan-1-aminium chloride)2 (C12(DUAC)2) of its precursor molecule.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.
The local electric field (LEF) plays an important role in the catalytic process; however, the precise construction and manipulation of the electric field microenvironment around the active site remains a significant challenge. Here, we have developed a supramolecular strategy for the implementation of a LEF by introducing the host macrocycle 18-crown-6 (18C6) into a cobalt phthalocyanine (CoPc)-containing covalent organic framework (COF). Utilizing the supramolecular interaction between 18C6 and potassium ion (K), a locally enhanced K concentration around CoPc can be built to generate a LEF microenvironment around the catalytically active Co site.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085, India.
The precise identification of various toxic gases is important to prevent health and environmental hazards using cost-effective, efficient, metal oxide-based chemiresistive sensing methods. This study explores the sensing properties of a chemiresistive sensor based on a ZnSnO-SnO microcomposite for detecting -butanol vapours. The microcomposite, enriched with oxygen vacancies, was thoroughly characterized, confirming its structure, crystallinity, morphology and elemental composition.
View Article and Find Full Text PDFChemSusChem
January 2025
Leiden University: Universiteit Leiden, Leiden Institute of Chemistry, Einsteinweg 55, Room number EE4.19, 2333 CC, Leiden, NETHERLANDS, KINGDOM OF THE.
Electrocatalysis in metal-organic frameworks is an interplay between the diffusion of charges, the intrinsic catalytic rate, and the mass-transport of reactants through the pores. Here a systematic study is carried out to investigate the role of the electrolyte nature and concentration on the oxygen reduction reaction (ORR) with the PCN-224(Co) MOF in aqueous electrolyte. It was found that the ORR activity is slightly influenced by the nature of the ions in solution, providing that the ionic strength is high enough to minimize the resistivity during the measurement.
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