The aim of this work was to evaluate the transformation of manganese oxide (hausmannite) by microscopic filamentous fungus and the effects of the transformation on mobility and bioavailability of arsenic. Our results showed that the strain CBS 140837 greatly affected the stability of hausmannite and induced its transformation into biogenic crystals of manganese oxalates-falottaite and lindbergite. The transformation was enabled by fungal acidolysis of hausmannite and subsequent release of manganese ions into the culture medium. While almost 45% of manganese was bioextracted, the arsenic content in manganese precipitates increased throughout the 25-day static cultivation of fungus. This significantly decreased the bioavailability of arsenic for the fungus. These results highlight the unique strain's ability to act as an active geochemical factor via its ability to acidify its environment and to induce formation of biogenic minerals. This affects not only the manganese speciation, but also bioaccumulation of potentially toxic metals and metalloids associated with manganese oxides, including arsenic.
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http://dx.doi.org/10.3390/jof6040270 | DOI Listing |
J Expo Sci Environ Epidemiol
January 2025
Department of Environmental Sciences & Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Background: Preterm birth (PTB) is a common pregnancy complication associated with significant neonatal morbidity. Prenatal exposure to environmental chemicals, including toxic and/or essential metal(loid)s, may contribute to PTB risk.
Objective: We aimed to summarize the epidemiologic evidence of the associations among levels of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), manganese (Mn), lead (Pb), and zinc (Zn) assessed during the prenatal period and PTB or gestational age at delivery; to assess the quality of the literature and strength of evidence for an effect for each metal; and to provide recommendations for future research.
Sci Rep
January 2025
Department of Physics, Khalifa University of Science and Technology, 127788, Abu Dhabi, United Arab Emirates.
In this study, biopolymer composites based on chitosan (CS) with enhanced optical properties were functionalized using Manganese metal complexes and black tea solution dyes. The results indicate that CS with Mn-complexes can produce polymer hybrids with high absorption, high refractive index and controlled optical band gaps, with a significant reduction from 6.24 eV to 1.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Fujian Province Key Laboratory of Pollution Control and Resource Reuse, College of Environmental and Resource Science, Fujian Normal University, Fuzhou, 350007, Fujian Province, China. Electronic address:
Since the widespread use of antibiotics, the residues of antibiotics have frequently been detected in various water sources, making antibiotic pollution an urgent environmental issue. In this paper, one-step green synthetic reduced graphene/manganese nanoparticles (rGO/Mn NPs) composites have been utilized as a novel environmentally-friendly catalyst for tetracycline (TC) removal. The results demonstrated that rGO/Mn NPs exhibit excellent adsorption performance for TC, and can efficiently activate sodium persulfate (PDS) to oxidize and degrade TC.
View Article and Find Full Text PDFPharmaceutics
January 2025
Department of Pharmacy, "Federico II" University of Naples, 80131 Naples, Italy.
Arginase (ARG) is a binuclear manganese-containing metalloenzyme that can convert L-arginine to L-ornithine and urea and plays a key role in the urea cycle. It also mediates different cellular functions and processes such as proliferation, senescence, apoptosis, autophagy, and inflammatory responses in various cell types. In mammals, there are two isoenzymes, ARG-1 and ARG-2; they are functionally similar, but their coding genes, tissue distribution, subcellular localization, and molecular regulation are distinct.
View Article and Find Full Text PDFSensors (Basel)
January 2025
Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang 110004, China.
Fluorescent iron nanoclusters are emerging fluorescent nanomaterials. Herein, we synthesized hemoglobin-coated iron nanoclusters (Hb-Fe NCs) with a significant fluorescence emission peak at 615 nm and investigated the inner-filter effect of fluorescence induced by a manganese dioxide nanosheet (MnO NS). The fluorescence quenching of Hb-Fe NCs by a MnO NS can be significantly reversed by the addition of ascorbic acid.
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