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This study aims to evaluate the intrinsic vulnerability of the Moeda Syncline, located in the western portion of the Quadrilátero Ferrífero in the State of Minas Gerais, Brazil. This region stands out for hosting important gold and iron ore mines and is the target of geological studies due to its structural complexity and economic importance. The Moeda Syncline is responsible for feeding springs and important tributaries in the hydrographic basins of the Velhas and Paraopeba rivers, thus contributing with a great part of the water consumed by the population of the Metropolitan Region of Belo Horizonte (RMBH). The main threats to the sustainable use of water in the Moeda Syncline are urban expansion and mining enterprises. From the mapping of vulnerability to contamination it is possible to identify the areas that need to receive priority treatment. To assess the vulnerability of aquifers, four methods were selected according to the types of aquifers, namely: DRASTIC, SINTACS, GOD and EPIK. The DRASTIC method was developed to be used in any type of aquifer, the SINTACS method was developed for fissural aquifers, the GOD method for porous aquifers and the EPIK method for karst aquifers. In addition to the application of the proposed methods, modifications were made in order to adapt the method to the physical characteristics of the region, considering the less efficient parameters. From the results obtained, it was found that the most appropriate method to assess the vulnerability of the study area are those specific to each type of aquifer, considering that the proposed adaptations proved to be more efficient than the original methods. In addition, it was observed that the DRASTIC method, developed for all types of aquifers, demonstrates efficacy by indicating that the main aquifers susceptible to contamination are those of the cover layers, Cauê and Gandarela.

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Titanium oxide is of fundamental strategic importance in the global market as it is used as a raw material by several industries, such as medical prostheses, paints, pigments, and, more recently, electronic chips. The main source of titanium oxide is ilmenite, a mineral deposited in many coastal areas of the world, including the state of Rio Grande do Sul in Southern Brazil in its central coastal plain, under specific morphodynamic conditions. Some geological targets, such as mineral oxides, show distinct thermal spectral features. The present study evaluated the surface concentration of ilmenite in Southern Brazil using thermal spectroscopy (µFT-IR). The emissivity spectral signatures of pure ilmenite between 8 and 14 µm were determined and some indicative features were identified. The obtained emissivity spectrum has been employed as a reference for the Spectral Angle Mapper (SAM) and Linear Spectral Unmixing (LSU) image classification algorithms. An image from the Advanced Spaceborne Thermal Emission Radiometer (ASTER) sensor (AST_05 emissivity product) was used to recognize the occurrence and assess the richness of the ilmenite. The outcomes of the present study indicated pixels with ilmenite concentration between 0 and 29.6%, with the highest concentration occurring under the transgressive dune field. In contrast, a lower concentration is found in the backshore. To obtain the degree of purity of the ilmenite, a quantitative microanalysis of the samples was conducted in a scanning electron microscope (SEM), and the results indicated that 80% of the minerals were ilmenite. Qualitative microanalysis showed that ilmenite is in the primary alteration phase, with a low degree of weathering and a lower concentration of impurities. Integrated techniques for analyzing multispectral and hyperspectral data in the thermal infrared were able to identify and map minerals rich in titanium oxide (ilmenite) quickly, effectively, at low cost, and non-destructively.

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BACKGROUND: Insects like Gryllus assimilis have an excellent nutritional profile, including iron. However, the bioavailability of this iron and its effects on intestinal health and oxidative balance remain unclear. To enhance acceptance, insects can be used in powder form and combined with common flours. OBJECTIVE: This study evaluates the effects of Gryllus assimilis powder, alone or with soy flour, on iron bioavailability, intestinal health, and oxidative balance in rodents. METHODS: Using the hemoglobin depletion/repletion method, 32 male Wistar rats were divided into four groups: A (standard diet + ferrous sulfate), B (diet + Gryllus assimilis + soy flour), C (diet + Gryllus assimilis), and D (diet + soy flour). Hemoglobin levels, regeneration efficiency, biological value, serum markers, intestinal health, and oxidative balance were assessed. RESULTS: Food intake, weight gain, and bioavailability measures showed no differences. However, the Gryllus + soy group showed higher weekly and final hemoglobin levels than Gryllus alone. This combination also improved acetic acid levels, fecal moisture, and oxidative balance, increasing superoxide dismutase activity while reducing peroxidation products compared to Gryllus alone. CONCLUSION: These findings highlight the potential benefits of combining Gryllus assimilis with soy flour for iron bioavailability and overall health.

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Rice (Oryza sativa L.) is a staple food for more than half of the human population. Rice plants are cultivated in several different environments, and face various abiotic stresses, including nutritional imbalance in soils. The ionome, the inorganic composition of an organism, is known to be tightly regulated, as changes in concentration of one element affect concentrations of others. Iron (Fe) is an essential element that is involved in redox reactions, nitrogen metabolism and chlorophyll synthesis. The hallmark of Fe deficiency in plants is leaf chlorosis, a phenotype known to be alleviated by deficiencies of other elements, such as phosphorus (P). Aluminum (Al) is abundant in soils and limits plant growth in acidic soils. Despite its well-established detrimental effects, Al has been proposed to have a positive effect on growth for some species, but little is known about this phenomenon. Here we aim to understand whether Al affects Fe homeostasis in rice. We found that Al alleviated Fe deficiency-induced chlorosis. +Al-Fe treatment decreased expression of Fe deficiency marker genes and partially recovered photosynthesis. We also observed that Al induced expression of a P deficiency marker gene, and addition of excess P to nutrient solution reversed effects of Al on chlorosis. Our data show that Al alleviates Fe deficiency-induced chlorosis, and suggests that this occurs indirectly by inducing P deficiency in leaves.

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Waste pile substrates from Fe mining may carry potentially toxic elements (PTE). Rehabilitation efforts must maintain soil vegetation cover effectively, avoiding the dispersion of particulate matter and reducing the risk to the environment and human health. Therefore, this study aims to evaluate the pseudo-total and extractable contents, perform chemical fractionation, and assess the bioaccessibility and risk of PTE in waste piles of Fe mining in the Eastern Amazon. Soils were sampled from waste piles in different stages of environmental rehabilitation and from non-rehabilitated and native forest areas. The waste materials exhibit mean pseudo-total concentrations of Zn, Ni, Cr, and Cu that exceed the Brazilian soil quality threshold. However, they do not surpass reference values for human health safety. In addition, these elements are predominantly associated with the residual fraction, suggesting low availability. Among the 11 PTE evaluated, only Al, Cu, Fe, Mn, and Zn presented concentrations that were bioaccessible to the gastrointestinal tract. At the same time, Al, Fe, and Mn showed lung bioaccessibility. Soil properties limiting PTE extractability and bioaccessibility include pH and base saturation. Considering only elements above threshold levels, no environmental risk was observed, and the human health risk was considered insignificant for adult oral and inhalation exposure routes. Finally, the results show that high pseudo-total PTE contents in the analyzed Fe waste piles do not necessarily indicate high risks. However, substrate properties should be monitored over time to better understand their potential impacts and the main factors influencing their bioavailability.

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One of the biggest public health problems globally is that of iron deficiency anemia. The present research aimed to determine the effect of prebiotics along with iron fortification on iron biomarkers in female anemic rats as some evidence suggests that prebiotics convert increase the solubility of iron, thereby enhancing its absorption. A total of 126 Sprague Dawley rats were fed with sixteen different types of fortified feed containing prebiotics (Inulin + Galacto Oligosaccharides) and Iron Fortificants (Sodium Ferric Ethylenediaminetetraacetate + Ferrous Sulphate). The duration of the trials was 3 months aimed at determining the effect of iron fortification and prebiotics on different iron biomarkers including Hemoglobin (Hb), Hematocrit, Red Blood Cell (RBC) count, Mean Corpuscular Volume (MCV), Mean Corpuscular Hemoglobin (MCH) and Mean Corpuscular Hemoglobin Concentration (MCHC). The trials resulted in statistically significant improved iron biomarkers among female anemic rats (P-value < 0.05). It was concluded that iron fortification and prebiotics in combination were able to increase the levels of iron biomarkers in female anemic rats.

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There is a debate about the implications of the effect of nanoparticles or nanomaterials on edible plants and soil organisms. Earthworms have been used to evaluate soil quality, reproduction, survival, and other biochemical parameters when organisms are exposed to nanomaterials. Most studies have been performed in laboratory settings, and little has been studied under realistic conditions, especially when earthworms and corn plants share the same natural soil and organic matter space. The objective of this research was to evaluate concentrations of 10, 100, 200, 400, and 800 mg kg-1 of iron nanoparticles (Fe NPs, combination of magnetite [Fe3O4] and hematite [α-Fe2O3]) on the growth and development of maize plants (Zea mays L.), and of the reproduction parameters of Eisenia fetida during 110 days of exposure. The results demonstrated that concentrations of 100 and 400 mg kg-1 of Fe NPs positively changed some morphological, photosynthetic, and yield parameters in maize crops. Unexpectedly, concentrations of 400 and 800 mg kg-1 decreased earthworm population but, at the same time, increased the number of juveniles. With this holistic approach experiment, it was demonstrated that the use of Fe nanoparticles as a biostimulant can promote corn yield parameters, but at the same time it impacts the reproductive capacity of the earthworms. However, it is necessary to explore the long-term effect of the proposed nanomaterials in agriculture to rule out risks or ecological implications in agricultural systems.

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Microfibrillated cellulose (MFC), a sustainable material derived from biomass, stands out as an environmentally friendly alternative for developing chemical sensors owing to its advantageous properties including high porosity, surface area, and available surface functional groups. Herein, we propose a simple and low-cost strategy for developing cellulose-based strips for the colorimetric detection of total iron in water. The strips were prepared by functionalizing MFC casting membranes with 1-(2-Thiazolylazo)-2-naphthol (TAN), which was characterized by structural and morphological techniques. The sensing ability of the MFC@TAN strips towards total iron was evaluated under distinct reaction times by digital image colorimetry. Under optimal conditions, the strips yielded limits of detections of 0.08 and 0.09 mg L-1 using the Blue (5 min) and Red (30 min) channels, respectively. Additionally, the sensor enabled total iron detection in tap water in the concentration range of 0.08-0.70 mg L-1, showing no significant difference against the standard method. When compared to commercial papers, the MFC@TAN strips showed enhanced sensing performance owing to their more porous and interpenetrating structure, which benefited the TAN immobilization and reaction with Fe2+. Our cellulose-based sensor strips offer a compelling combination of simplicity in manufacturing and cost-effectiveness, highlighting their potential for routine water analysis.

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The frequency and intensity of harmful cyanobacterial blooms have increased in the last decades, posing a risk to public health since conventional water treatments do not effectively remove extracellular cyanotoxins. Consequently, advanced technologies such as the Fenton process are required to ensure water safety. The cyanotoxin cylindrospermopsin (CYN) demands special attention, as it is abundant in the extracellular fraction and has a high toxicological potential. Hence, this study aimed to assess the application of the Fenton process for the oxidation of CYN spiked in natural water from Paranoá Lake (Brasília, Brazil). The H2O2/Fe(II) molar ratio was evaluated from 0.2 to 3.4, with an optimum molar ratio of 0.4, achieving a CYN degradation efficiency of 97.8% when using 100 µM of H2O2 and 250 µM of Fe(II). The CYN degradation efficiency, using 75 µM of H2O2 and 187.5 µM of Fe(II), decreased by increasing the initial pH (from 96.2% at pH 2 to 23.0% at pH 9) and the initial CYN concentration (from 93.7% at 0.05 µM of CYN to 85.0% at 0.2 µM of CYN). At the optimum H2O2/Fe(II) molar ratio of 0.4, the hydroxy radical scavengers tested (124.3 µM C of algogenic organic matter, 5 mg L-1 of humic acid, and 513.3 µM of methanol) did not considerably affect the CYN degradation, reaching a maximum CYN degradation reduction from 98.3% to 82.2%.

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The rise of atmospheric oxygen as a result of photosynthesis in cyanobacteria and chloroplasts has transformed most environmental iron into the ferric state. In contrast, cells within organisms maintain a reducing internal milieu and utilize predominantly ferrous iron. Ferric reductases are enzymes that transfer electrons to ferric ions, either extracellularly or within endocytic vesicles, enabling cellular ferrous iron uptake through Divalent Metal Transporter 1. In mammals, duodenal cytochrome b is a ferric reductase of the intestinal epithelium, but how insects reduce and absorb dietary iron remains unknown. Here we provide indirect evidence of extracellular ferric reductase activity in a small subset of Drosophila melanogaster intestinal epithelial cells, positioned at the neck of the midgut's anterior region. Dietary-supplemented bathophenanthroline sulphate (BPS) captures locally generated ferrous iron and precipitates into pink granules, whose chemical identity was probed combining in situ X-ray absorption near edge structure and electron paramagnetic resonance spectroscopies. An increased presence of manganese ions upon BPS feeding was also found. Control animals were fed with ferric ammonium citrate, which is accumulated into ferritin iron in distinct intestinal subregions suggesting iron trafficking between different cells inside the animal. Spectroscopic signals from the biological samples were compared to purified Drosophila and horse spleen ferritin and to chemically synthesized BPS-iron and BPS-manganese complexes. The results corroborated the presence of BPS-iron in a newly identified ferric iron reductase region of the intestine, which we propose constitutes the major site of iron absorption in this organism.

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Color and morphology are some of the most intriguing traits of plant galls, whose patterns resemble fruits and flowers. Many hypotheses were proposed to explain the involvement of anthocyanin accumulation with the development of red gall hues, whose mechanisms seem idiosyncratic. Anthocyanins are related to photoprotective strategies in green tissues and metal accumulation in some flowers. Despite that, the combination of such physiological phenomena has been neglected for galls, which are photosynthetic neoplasms genetically similar to reproductive organs. Here, we integrated different perspectives by measuring photosynthetic pigment and anthocyanin concentration combined with fluorescence quenching analysis, antioxidant activity assays, and histochemical elemental mapping in red and green galls induced by Espinosa nothofagi (Hymenoptera) on Nothofagus obliqua (Nothofagaceae). We found no relationship between high anthocyanin concentrations, light exposure, and red coloration in galls as anthocyanin concentrations were higher in the outermost tissues of green galls than in red galls. Red galls presented higher concentrations of total chlorophyll and lower carotenoid concentrations than green galls and leaves, which correlated with their highest photosynthetic activity and iron accumulation. The red color coincides with the accumulation of aluminum and Fe3+ and the lowest antioxidant capacity in the gall outer tissue. The high antioxidant capacity of N. obliqua galls and the Fe2+ and Fe3+ distribution are related to high photosynthesis, Fe-use efficiency in galls, and the supply of Fe to the inducer diet. Overall, iron metabolism connects the high photosynthesis activity to the red gall color in the presence of low anthocyanin concentrations, like some flowers.

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Banded iron formations (BIFs) are chemical sedimentary rocks commonly utilized for exploring the chemistry and redox state of the Precambrian ocean. Despite their significance, many aspects regarding the crystallization pathways of iron oxides in BIFs remain loosely constrained. In this study, we combine magnetic properties characterization with high-resolution optical and electron imaging of finely laminated BIFs from the 2.7 Ga Carajás Formation, Brazil, to investigate their nature and potential for preserving ancient environmental conditions. Our findings reveal that magnetite, in the form of large 0.1-0.5 mm crystals, is the main iron oxide, with an overall averaged saturation magnetization (Ms) of 25 Am2/kg (corresponding to ~27 wt% of magnetite) over the studied 230 m of the sequence. Nevertheless, the non-negligible contribution of minerals with higher coercivity suggests variable proportions of hematite along the core. Additionally, we observe non-uniform behavior in magnetite grains, with distinct populations identified through low-temperature measurements of the Verwey transition. Petrographic observations indicate that the original sediment was an Fe-Si mud consisting of a ferrihydrite-silica mixture formed in the water column. This assemblage was rapidly transformed into nano-scale hematite embedded in silica as indicated by a honeycomb structure composed of Si-spherules distributed in a microscale hematite matrix. Textural relationships show that the nucleation of magnetite started during or soon after the formation of hematite, as indicated by the preservation of the Si-spherules within magnetite cores. Further magnetite overgrowth stages are characterized by inclusion-free rims, associated with continuous Si supply during the evolving diagenetic or early metamorphic stages. These findings, combined with existing literature, suggest that ferrihydrite precipitated alongside Si and organic material, later crystallizing as hematite on the seafloor. Anaerobic respiration by Fe(III)-reducing microorganisms likely contributed to early magnetite formation in a fluid-saturated, unconsolidated sediment. Subsequent low-grade metamorphism and Si mobilization led to palisade quartz precipitation and a second stage of magnetite growth likely formed at the expense of matrix hematite through thermochemical Fe(III) reduction. Low-temperature magnetic analyses revealed that the two generations of magnetite core and rim are associated with specific stoichiometry.

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BACKGROUND AND PURPOSE: Bioavailability studies and observational evidence suggest that heme iron (HI) may have greater impact on iron status indicators compared with non-heme iron (NHI). This systematic review and meta-analysis aimed to review the current evidence on the effect of the administration of HI compared with NHI for improving iron status in non-hospitalized population groups. METHODS: We searched Pubmed, CENTRAL, Scopus, Web of Science, and LILACS from inception to July 2024. There was no language restriction or exclusion based on age or iron status. Only randomized controlled trials comparing HI with NHI were considered. A random-effects meta-analysis was performed to compare the effect of treatments for iron status indicators and total side effects (including gastrointestinal side effects). We measured the certainty of the evidence (CoE) using GRADE assessment. RESULTS: After screening 3097 articles, 13 studies were included. Most of the interventions used HI in low doses combined with NHI. The meta-analysis showed higher hemoglobin increases in children with anemia or low iron stores receiving HI (MD 1.06 g/dL; 95% CI: 0.34; 1.78; CoE: very low). No statistically significant difference between interventions were found for any iron status indicator in the other population subgroups (CoE: very low). Participants receiving HI had a 38% relative risk reduction of total side effects compared to NHI (RR 0.62; 95% CI 0.40; 0.96; CoE: very low). CONCLUSION: The current evidence comparing HI with NHI is very limited, preliminary findings suggest that interventions using HI may result in fewer side effects and may be superior in children with iron deficiency or anemia. However, given the very low certainty of the evidence, these results need further investigation through high-quality clinical trials. PROTOCOL REGISTRATION: CRD42023483157.

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Pregnancy increases the demand for essential metal ions to support fetal development, making the maternal metal ion status a critical determinant of perinatal outcomes. This prospective cohort study examined changes in metal ion levels across the three trimesters, evaluated the influence of preexisting metabolic conditions on the metal ion status, and assessed the associations between maternal metal ion levels and perinatal outcomes in 206 pregnant women from the Biochemical and Epigenetic Origin of Overweight and Obesity (OBESO) cohort receiving care at the Instituto Nacional de Perinatología in Mexico City from 2017 to 2020. Six essential metal ions (iron, zinc, copper, calcium, magnesium, and phosphorus) were measured in blood samples using inductively coupled plasma optic emission spectrometry. Significant variations in the metal ion levels were observed across the trimesters, with notable decreases in iron and magnesium and increases in copper as pregnancies progressed. Maternal hypothyroidism was associated with significantly low levels of zinc and magnesium during pregnancy. Regression analyses revealed robust associations between maternal metal ion levels and perinatal outcomes. For instance, declining magnesium levels as pregnancies progressed were positively associated with gestational diabetes (OR: 2.92, p = 0.04; OR: 2.72, p = 0.03). The maternal metal ion status significantly influences perinatal outcomes.

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Abstract Introduction: Iron (Fe) and manganese (Mn) are bioessential micronutrients for plants but can impair the energetic metabolism when present at high levels. Objective: To assess the photosynthetic performance and oxidative damages in Rhizophora mangle L. leaf tissues at low and high concentrations of Fe (74 and 195 mg kg-1; Feleaf) and Mn (65 and 414 mg kg-1; Mnleaf). Methods: Photosynthetic pigments, chlorophyll a fluorescence, leaf CO2 assimilation and gas exchange and DPPH• radical scavenging capacity were sampled in R. mangle growing in estuarine forests in the North region of Espírito Santo State and the extreme South of Bahia State (Brazil) showing low and high Feleaf and Mnleaf. Results: Effects of high Fe and Mn were not identified on pigment levels. The increase in Feleaf and Mnleaf at the levels observed in this assessment had a positive effect on the number of reaction centers and on the efficiency of the oxygen-evolving complex, evaluated as K-band, while no changes were found in the parameters related to the excitation trapping efficiency at the active center of photosystem II. Distinct interference patterns of Fe and Mn on the functional processes of photosynthesis were identified, especially on CO2 assimilation and reactive oxygen species metabolism, with major effects on CO2 assimilation and carboxylation efficiency of Rubisco at high Mnleaf. Conclusion: These findings demonstrate the efficiency of R. mangle in positively regulating the electron transport chain in response to high Fe and Mn, at least in terms of the preservation of structure and functionality of the plant photosynthetic apparatus. Moreover, interference of high Mnleaf in R. mangle occurs at non-stomatal and biochemical levels. There is an antagonistic interference of these trace elements with the physiology of R. mangle, which is a dominant species in Brazilian mangroves.

Resumen Introducción: El hierro (Fe) y el manganeso (Mn) son micronutrientes bioesenciales para las plantas, pero pueden afectar el metabolismo energético cuando están presentes en niveles altos. Objetivo: Evaluar el desempeño fotosintético y los daños oxidativos en tejidos foliares de Rhizophora mangle L. a bajas y altas concentraciones de Fe (74 y 195 mg kg-1; Feleaf) y Mn (65 y 414 mg kg-1; Mnleaf). Métodos: Se muestrearon pigmentos fotosintéticos, fluorescencia de clorofila a, asimilación e intercambio de gases de CO2 foliar y capacidad de eliminación de radicales DPPH• en R. mangle que crece en bosques de estuarios en la región Norte del estado de Espírito Santo y el extremo Sur del Estado de Bahía (Brasil) mostrando Feleaf y Mnleaf bajos y altos. Resultados: No se identificaron efectos de niveles elevados de Fe y Mn en los niveles de pigmento. El aumento de Feleaf y Mnleaf en los niveles observados en esta evaluación tuvo un efecto positivo en el número de centros de reacción y en la eficiencia del complejo generador de oxígeno, evaluado como banda K, mientras que no se encontraron cambios en los parámetros relacionados con la eficiencia de atrapamiento de excitación en el centro activo del fotosistema II. Se identificaron distintos patrones de interferencia de Fe y Mn en los procesos funcionales de la fotosíntesis, especialmente en la asimilación de CO2 y el metabolismo de las especies reactivas de oxígeno, con efectos importantes en la asimilación de CO2 y la eficiencia de carboxilación de Rubisco a niveles altos de Mnleaf. Conclusión: Los hallazgos demuestran la eficiencia de R. mangle en la regulación positiva de la cadena de transporte de electrones en respuesta a los altos niveles de Fe y Mn, al menos en términos de preservación de la estructura y funcionalidad del aparato fotosintético de la planta. Además, la interferencia de Mnleaf alto en R. mangle se presenta a niveles no estomáticos y bioquímicos. Hay interferencia antagónica de estos oligoelementos con la fisiología de R. mangle, que es una especie dominante en los manglares brasileños.

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The improvement of the sono-photo-Fenton process at nearby neutral pH (~ 6.2) and high iron concentration (5 mg L-1) by the addition of the juice of Passiflora edulis f. flavicarpa Degener (yellow passion fruit) on the degradation of imipenem in water is reported for the first time. Considering that the combination of sonochemistry with photo-Fenton takes advantage of the in situ sonogeneration of H2O2, the effects of frequency and acoustic power for the H2O2 accumulation were established initially. The sonication at 578 kHz and 23.8 W favored the H2O2 generation. Using such frequency and power, the antibiotic was synergistically degraded by the sono-photo-Fenton system in distilled water, leading to ~ 90% removal at 120 min of treatment. An atomic charge analysis showed that thioether, ß-lactam ring, and carboxylic acid moieties on the imipenem structure were very prone to interactions with the HO• generated in the sono-photo-Fenton process. Indeed, the primary transformation products (TPs) came from the oxidation of the thioether, the opening of the ß-lactam ring, and decarboxylations. Such TPs had a lower probability than imipenem to be active against bacteria. Besides, the addition of small amounts (2.5-10 µL) of the yellow passion fruit juice to the sono-photo-Fenton system significantly improved the pharmaceutical elimination. However, a juice excess (e.g., 100 µL) caused a detrimental effect due to competing effects by radicals. The juice of the yellow passion fruit induced analogous effects to citric acid (a commercial complexing agent) on the sono-photo-Fenton process. Indeed, the degradation of imipenem in simulated hospital wastewater by sono-photo-Fenton was improved by the yellow passion fruit juice (~ 38% at 60 min), and it was similar to that with citric acid (~ 39% of removal at 60 min). Thus, the commercial reagent can be replaced by a natural and low-cost complexing agent (e.g., yellow passion fruit juice or fruit wastes containing citric acid), as an enhancer of the sono-photo-Fenton process carried out at near-neutral pH and high iron concentration for degrading imipenem in water.

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Glycation-induced stress (G-iS) is a physiological phenomenon that leads to the formation of advanced glycation end-products, triggering detrimental effects such as oxidative stress, inflammation, and damage to intracellular structures, tissues, and organs. This process is particularly relevant because it has been associated with various human pathologies, including cancer, neurodegenerative diseases, and diabetes. As therapeutic alternatives, coordination compounds with antioxidant activity show promising potential due to their versatility in attenuating oxidative stress and inflammation. Herein, we investigated the antioxidant-related protective potential of a series of complexes: [Cu(II)(BMPA)Cl2] (1), [Fe(III)(BMPA)Cl3] (2), and [Cl(BMPA)MnII-(µ-Cl)2-MnII(BMPA)-(µ-Cl)- MnII(BMPA)(Cl)2]•5H2O (3), all synthesized with the ligand bis-(2-pyridylmethyl)amine (BMPA) in Saccharomyces cerevisiae exposed to G-iS caused by methylglyoxal (MG). Pre- treatment with complexes 1-3 proved highly effective, increasing yeast tolerance to G-iS and attenuating mitochondrial dysfunction. This observed phenotype appears to result from a reduction in intracellular oxidation, lipid peroxidation levels, and glycation. Additionally, an increase in the activity of the antioxidant enzymes superoxide dismutase and catalase was observed following treatment with complexes 1-3. Notably, although complexes 1-3 provided significant protection against oxidative stress induced by H2O2 and menadione, their protective role was more effective against MG-induced glycation stress. Our results indicate that these complexes possess both antiglycation and antioxidant properties, warranting further investigation as potential interventions for mitigating glycation and oxidative stress-related pathologies.

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Cyanobacteria, often overlooked in traditional agriculture, are gaining recognition for their roles in enhancing plant growth and soil health through diverse mechanisms. This review examines their multifaceted contributions to agricultural systems, highlighting their proficiency in auxin production, which promotes plant growth and development. Additionally, we examined cyanobacteria's ability to produce siderophores that enhance iron absorption and address micronutrient deficiencies, as well as their capacity for nitrogen fixation, which converts atmospheric nitrogen into a form that plants can utilize, all with the goal of reducing reliance on synthetic fertilizers. A meta-analysis of existing studies indicates significant positive effects of cyanobacteria on crop yield, although variability exists. While some research shows considerable yield increases, other studies report non-significant changes, suggesting benefits may depend on specific conditions and crop types. The overall random-effects model estimate indicates a significant aggregate effect, with a few exceptions, emphasizing the need for further research to optimize the use of cyanobacteria as biofertilizers. Although cyanobacteria-based products are limited in comparison to seaweed-derived alternatives, for instance, ongoing challenges include regulatory issues and production costs. Integrating cultivation with wastewater treatment could enhance competitiveness and viability in the agricultural market.

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The aim of this study was to identify, using proteomics, the molecular alterations caused by human serum exposure to Klebsiella pneumoniae ACH2. The analysis was performed under two different conditions, native serum from healthy donors and heat-inactivated serum (to inactivate the complement system), and at two different times, after 1 and 4 h of serum exposure. More than 1,000 bacterial proteins were identified at each time point. Enterobactin, a siderophore involved in iron uptake, and proteins involved in translation were upregulated at 1 h, while the chaperone ProQ and the glyoxylate cycle were identified after 4 h. Enzymes involved in the stress response were downregulated, and the SOD activity was validated using an enzymatic assay. In addition, an intricate metabolic adaptation was observed, with pyruvate and thiamine possibly involved in survival and virulence in the first hour of serum exposure. The addition of exogenous thiamine contributes to bacterial growth in human serum, corroborating this result. During 4 h of serum exposure, the glyoxylate cycle (GC) probably plays a central role, and the addition of exogenous succinate suppresses the GC, inducing a decrease in serum resistance. Therefore, serum exposure causes important changes in iron acquisition, the expression of virulence factors, and metabolic reprogramming, which could contribute to bacterial serum resistance.

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Increased intramitochondrial free iron is a key feature of various liver diseases, leading to oxidative stress, mitochondrial dysfunction, and liver damage. Polydatin is a polyphenol with a hepatoprotective effect, which has been attributed to its ability to enhance mitochondrial oxidative metabolism and antioxidant defenses, thereby inhibiting reactive oxygen species (ROS) dependent cellular damage processes and liver diseases. However, it has not been explored whether polydatin is able to exert its effects by protecting the phospholipid cardiolipin against damage from excess iron. Cardiolipin maintains the integrity and function of electron transport chain (ETC) complexes and keeps cytochrome c bound to mitochondria, avoiding uncontrolled apoptosis. Therefore, the effect of polydatin on oxidative lipid damage, ETC activity, cytochrome levels, and ROS production was explored in iron-exposed rat liver mitochondria. Fe2+ increased lipid peroxidation, decreased cardiolipin and cytochromes c + c1 and aa3 levels, inhibited ETC complex activities, and dramatically increased ROS production. Preincubation with polydatin prevented all these effects to a variable degree. These results suggest that the hepatoprotective mechanism of polydatin involves the attenuation of free radical production by iron, which enhances cardiolipin levels by counteracting membrane lipid peroxidation. This prevents the loss of cytochromes, improves ETC function, and decreases mitochondrial ROS production.