Articoli di riviste: "Manganese"

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Idrus, Arifudin, E. M. Ati, A. Harijoko e F. M. Meyer. "Characteristics and Origin of Sedimentary-Related Manganese Layers in Timor Island, Indonesia". Indonesian Journal on Geoscience 8, n. 4 (28 dicembre 2013): 191–203. http://dx.doi.org/10.17014/ijog.8.4.191-203.

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DOI: 10.17014/ijog.v8i4.169Sedimentary-related manganese layers have been discovered in South Central Timor Regency, Timor Island, Indonesia, which is tectonically active and being uplifted due to north-trending tectonic collision between Timor Island arc and Australian continental crust. The manganese layers of 2 to 10 cm-wide interbed with deep sea sedimentary rocks including reddish - reddish brown claystone, radiolarian chert, slate, marl as well as white and pinkish calcilutite of Nakfunu Formations. Stratigraphically, the rock formations are underlain by Bobonaro Formation. Two types of manganese ores found comprise manganese layers and manganese nodule. The manganese layers strongly deformed, lenticular, and segmented, are composed of manganite [MnO(OH)], groutite [MnO(OH)], pyrolusite (MnO2), lithioporite (Al,Li) MnO2(OH)2, and hollandite [Ba (Mn4+, Mn2+)8O16] associated with gangue minerals including calcite, quartz, limonite [FeO(OH)], hematite (Fe2O3), and barite (BaSO4). Whilst the nodule type is only composed of manganite and less limonite. Geochemically, the manganese layers have grade of 63 - 72 wt.% MnO, whereas the nodule one has grade of 63 - 69 wt.% MnO. Generally, iron in Mn ore is very low ranging from 0.2 to 1.54 wt.% Fe2O3, averaged 0.76 wt.%. Hence, Fe/Mn ratio which is very low (0.003 - 0.069), typically indicates a sedimentary origin, which is also supported by petrologic and petrographic data showing layering structure of manganite and lithioporite crystal/grain. Trace element geochemistry indicates that manganese ore was precipitated in a reduction condition. Rare earth element (REE) analysis of manganese ore shows an enrichment of cerium (Ce) suggesting that the ore is basically originated in a marine environment. The manganese nodule is interpreted to be formed by chemical concretion process of unsoluble metals (i.e. mangan, iron) in seawater (hydrogenous) and precipitated on deep sea bottom. On the other hand, the manganese layer is a detrital diagenetic deposit formed by Mn remobilization in seawater column, precipitated and sedimented on the deep sea bottom. Manganese layers have probably been influenced by ‘hydrothermal process’ of mud-volcano activities, proven by the presence of quartz and barite veinlets cutting the Mn layers, manganite recrystallization to be pyrolusite along veinlets cutting manganite and lithioporite layers, and the presence of pyrite and sulphur associated with Mn layers. Field data also exhibit that the significant manganese layers are mostly found around mud volcanoes. The closely spatial and genetic relationships between manganese layers and mud-volcanoes might also be an important guide for the exploration of Mn deposit in the region.

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Islamadina, B., e I. W. Warmada. "Mineralogy and geochemistry of Kliripan manganese ore deposit, Hargorejo Village, Kokap District, Kulonprogo Regency". IOP Conference Series: Earth and Environmental Science 1071, n. 1 (1 agosto 2022): 012026. http://dx.doi.org/10.1088/1755-1315/1071/1/012026.

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Abstract This study discusses the mineralogy and geochemistry of manganese deposits in the Kliripan area, where manganese had been mined since the Dutch occupancy until the 1970s. Although mining has been discontinued since then, the demand for manganese has increased in various industries, prompting exploration to continue to meet this demand. We performed petrographic, XRD, and XRF analysis of the ore and wall rock samples. Jasper and grainstone from the Sentolo Formation are the two lithologies where manganese mineralization occurs. Manganese-bearing minerals include pyrolusite, manganite, rhodochrosite, and lithiophorite, while the gangue minerals consist of quartz, calcite, hematite, and clay minerals. We interpret that Jasper is a product of alteration and has MnO content as high as 5.02 wt.%. Meanwhile, the economic grade manganese ore in grainstone has an MnO content up to 48.51 wt.%. The elements Ce, Zr, Co+Ni+Cu, are important discriminants to determine the type of manganese deposit. The results showed that the diagenetic process in reductive water formed the manganese ores. Oxidation of divalent manganese ion formed pyrolusite and manganite. Rhodochrosite crystallized when dilute manganese solution reacts with CO2 from limestone diagenesis. We concluded that the Kliripan manganese ore deposit has both hydrothermal and diagenetic deposits.

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Rybenko, I. A., I. D. Rozhikhina, O. I. Nokhrina e M. A. Golodova. "Rational application of high quality manganese concentrate". Izvestiya. Ferrous Metallurgy 67, n. 2 (21 aprile 2024): 237–44. http://dx.doi.org/10.17073/0368-0797-2024-2-237-244.

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The article presents the results of theoretical and experimental studies of manganese reduction processes from oxides of high-quality manganese concentrate obtained by hydrometallurgical enrichment of ferromanganese ores, as well as, from marokite (product of thermal synthesis of concentrate and dolomite) with carbon and silicon. The method of thermodynamic modeling with TERRA software complex determined the optimal temperatures and costs of reducing agents that ensure the complete reduction of manganese. It was found that any of the above-mentioned reducing agents, or a combination thereof in certain ratios, can be utilized as a reducing agent when using oxide manganese-containing materials for steel treatment. The results of experimental studies made it possible to develop technology for the production of marokite-manganite concentrate and monophase synthetic material (CaMnO3 ). They can be obtained using the technology developed by the authors, which includes mechanical and thermal treatment of a mixture of high-quality manganese concentrate and calcined dolomite or lime. Marokite-manganite concentrate is useful for alloying steel with manganese when it is smelted in an electric furnace or in a ladle furnace unit, and a monophasic synthetic material is efficient for the production of metal manganese. Based on the results of thermodynamic calculations and experimental studies, technological parameters for processing steel with marokite-manganite concentrate in an electric furnace and a ladle furnace unit are proposed. Monophasic synthetic material CaMnO3 should be used as the charge component for the production of metal manganese by the out-of-furnace aluminum thermal treatment, which will increase the terminality of the process, as well as the extraction of manganese at the level of 90 %. The results of experimental studies were obtained using modern research methods with laboratory and analytical equipment, as well as statistical processing methods.

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Winslow, James W. W., Kirsten H. Limesand e Ningning Zhao. "The Functions of ZIP8, ZIP14, and ZnT10 in the Regulation of Systemic Manganese Homeostasis". International Journal of Molecular Sciences 21, n. 9 (7 maggio 2020): 3304. http://dx.doi.org/10.3390/ijms21093304.

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As an essential nutrient, manganese is required for the regulation of numerous cellular processes, including cell growth, neuronal health, immune cell function, and antioxidant defense. However, excess manganese in the body is toxic and produces symptoms of neurological and behavioral defects, clinically known as manganism. Therefore, manganese balance needs to be tightly controlled. In the past eight years, mutations of genes encoding metal transporters ZIP8 (SLC39A8), ZIP14 (SLC39A14), and ZnT10 (SLC30A10) have been identified to cause dysregulated manganese homeostasis in humans, highlighting the critical roles of these genes in manganese metabolism. This review focuses on the most recent advances in the understanding of physiological functions of these three identified manganese transporters and summarizes the molecular mechanisms underlying how the loss of functions in these genes leads to impaired manganese homeostasis and human diseases.

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Fafure, A. A., A. O. Adekeye, L. A. Enye, A. A. Tijani, M. M. Ajao e E. E. Edem. "Ficus exasperata vahl improves manganese-induced neurotoxicity and motor dysfunction in mice". Anatomy Journal of Africa 7, n. 2 (4 luglio 2018): 1206–19. http://dx.doi.org/10.4314/aja.v7i2.174140.

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Manganese is an important element in the biological system, however, excessive exposure may lead to a neurological disorder known as manganism. The present study sought to investigate the ameliorative effects of Ficus exasperata Vahl (E.Vahl) on motor function and neuronal integrity of the Substantia nigra (SNc) and Corpus striatum (CPu) after acute exposure to manganese. Fifty adult male Balb/c mice weighing between 25 – 35g were divided into 5 groups – Group A (normal saline), Group B (Manganese), Group C (E.Vahl), Group D (Post-treatment), Group E (concurrent treatment). Manganese was intraperitoneally administered at 40mg/kg b.w, while E.Vahl orally at 200 mg/kg b.w. Motor coordination was assessed in the animals using Rotarod and Parallel Bar tests. Animals were later sacrificed; brain tissue extracted and processed for histology/immunohistochemistry. Manganese-exposed group showed decreased motor activity on the Rotarod test. Decreased motor activity shown by the increase in latency of turn (LoF) was recorded in the Parallel Bar test. Manganese induced activation of microglia and astrocytic cells in the SNc and CPu, which plays an important role in neurodegeneration as observed in the reduction of TH cells. Indistinct Nissl granules were also noticed in the manganese-exposed group. Treatment with E.Vahl produced significant motor improvement, as well as ameliorative effect on the histoarchitecture of the SNc and CPu. The present investigation has demonstrated the motor-enhancing and neuro-restorative potential of E.Vahl after manganese exposure in adult mice.Key Word: Neurodegeneration; Manganism; Ficus exasperata; Rotarod; immunohistochemistry.

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Raimo, Luis Augusto Di Loreto Di, Alexandra De Paiva Soares, Ricardo Santos Silva Amorim, Diana Medina Espinoza, Wellington De Azambuja Magalhães e Gilmar Nunes Torres. "APLICAÇÃO CONJUNTA DE MICRONUTRIENTE (Mn) E FUNGICIDA EM CULTIVO DE SOJA". Nativa 6, n. 1 (28 febbraio 2018): 09. http://dx.doi.org/10.31413/nativa.v6i1.4664.

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Objetivou-se com o presente estudo avaliar os efeitos da aplicação de manganês misturado ao fungicida, em plantas de soja. O experimento foi realizado na fazenda Beija-flor, município de Jaciara, estado de Mato Grosso. O delineamento utilizado foi o de blocos casualizados em esquema fatorial com parcela adicional (3x2+1) e quatro repetições. Foram aplicadas três doses de manganês (50, 100 e 150 g ha-1), com duas caldas de aplicação (manganês e manganês + fungicida), quando as plantas encontravam-se em estádio vegetativo e apresentavam 9 trifolíos completamente desenvolvidos (v10). Na parcela adicional (controle) foi aplicado apenas fungicida, também no estádio fenológico v10. As características avaliadas foram altura de plantas, massa de mil grãos, produtividade e teor de manganês foliar. Não ocorreram interações significativas entre os fatores avaliados. A produtividade não foi alterada pelas misturas realizadas, porém, apresentou diferenças significativas em função das doses de manganês, sendo a melhor dose equivalente a 100 g ha-1. A parcela adicional diferiu estatisticamente dos tratamentos que receberam as doses de 50 e 150 g ha-1 (sem fungicida) para a variável massa de mil grãos, e do tratamento que recebeu a dose de 100 g ha-1 de manganês misturado ao fungicida, para a produtividade de grãos. Conclui-se que a aplicação de manganês em mistura com fungicida não influenciou nas características agronômicas das plantas de soja avaliadas, apresentando-se como uma alternativa para diminuição de custos operacionais de aplicação em cultivos comerciais.Palavra-chave: Glycine max (L.) Merrill, antagonismo, produtividade, sinergismo. COMBINING MICRONUTRIENT (MN) AND FUNGICIDE APPLICATIONS IN SOY BEAN PRODUCTIVE SYSTEMS ABSTRACT: The objective of this study was to evaluate the effects of the application of manganese together with fungicide in soybean plants. The experiment was carried on Beija-flor farm, in municipality of Jaciara, Mato Grosso state. The experimental design used was randomized block design in a factorial arrangement with an additional plot (3x2+1) and four replications. Three manganese doses were applied (50, 100 and 150 g ha-1), with two application mixtures (manganese and manganese + fungicide), at vegetative stage, when the plants had 9 leafs (v10). On the aditional plot (control) only fungicide was applied, also phenological stage v10. The plant height, the mass of a thousand grains, the manganese content in the leaf and the yield, were the variables used to evaluate the effect of the applications. There were no significant interactions between the evaluated factors. Productivity was not altered by different mixtures, but there were found significant differences due to manganese doses. The best dose observed was the equivalent to 100 g ha-1 of manganese. The additional plot differed statistically from the treatments that received doses of 50 and 150 g ha-1 (without manganese) for the mass of thousand grains, and the treatment that received the dose of 100 g ha-1 manganese mixed with fungicide for grain yield. According to these results, the application of manganese and fungicides combined, do not influence the agronomic characteristics of soybean plants evaluated, that way is a valid alternative to reduce operating costs in soy bean production systems.Keywords: Glycine max (L.) Merrill, antagonism, productivity, synergism. DOI:

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Yang, Xin Sheng, Li Qin Yang, Li Lv e Yong Zhao. "Preparation and Properties of Novel Bonded Perovskite Manganite Oxides". Advanced Materials Research 79-82 (agosto 2009): 1723–26. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.1723.

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The two-phase perovskite manganese composites have potential application in the field of spintronics, as the observed enhanced low-field magnetoresistance in this kind of composite. To prepare the real manganite-based two-phase composition, the concept of bonded perovskite manganese was put forward recently. In this article we review main research results in these bonded perovskite manganite oxide composites and give some expectation.

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Новохацкая, А. А., e Г. Я. Акимов. "Роль избыточного марганца в формировании структуры и транспортных свойств манганита (Nd-=SUB=-0.67-=/SUB=-Sr-=SUB=-0.33-=/SUB=-)-=SUB=-1-x-=/SUB=-Mn-=SUB=-1+x-=/SUB=-О-=SUB=-3-=/SUB=- (x=0; 0.2), спеченного при 1273-1473 K". Физика твердого тела 60, n. 7 (2018): 1378. http://dx.doi.org/10.21883/ftt.2018.07.46127.009.

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AbstractThe Nd_0.67Sr_0.33MnO_3 manganite is a material promising for application as a cathode for medium-temperature solid oxide fuel elements. A high electrical conductivity of such a cathode is the parameter determining the efficiency of the operation of a fuel element. In this report, the effect of influence of excess manganese on the structure and the conductivity of manganite ceramics with compositions (Nd_0.67Sr_0.33)_1– x Mn_1 + x O_3± Δ ( x = 0, 0.2) sintered at temperatures 1273–1673 K is presented for the first time. The existence of 20% excess manganese in the initial manganite powder after sintering is shown to lead to that the conductivity of the obtained ceramics in the temperature range 823–1073 K is several times higher than the conductivity of the ceramics without excess manganese.

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Obeng, Sarfo Kwaku, Martin Kulhánek, Jiří Balík, Jindřich Černý e Ondřej Sedlář. "Manganese: From Soil to Human Health—A Comprehensive Overview of Its Biological and Environmental Significance". Nutrients 16, n. 20 (11 ottobre 2024): 3455. http://dx.doi.org/10.3390/nu16203455.

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Background: Manganese is an essential micronutrient that plays a pivotal role in environmental systems, plant physiology, and human health. This review comprehensively examines the manganese cycle in the environment, its absorption and transport mechanisms in plants, and the implications of manganese exposure to human health. Objectives: The objectives of this review are to (i) analyze the environmental cycling of manganese and its bioavailability, (ii) evaluate the role of manganese in plant metabolism and disease resistance, and (iii) assess the impact of manganese toxicity and deficiency on human health. Conclusion: This review highlights that while manganese is crucial for photosynthesis, enzyme activation, and resistance to plant diseases, both its deficiency and toxicity can have severe consequences. In plants, manganese deficiency can lead to impaired growth and reduced crop yields, while toxicity, particularly in acidic soils, can inhibit photosynthesis and stunt development. In humans, manganese is necessary for various physiological processes, but overexposure, especially in occupational settings, can result in neurodegenerative conditions such as manganism. The conclusion emphasizes the importance of managing manganese levels in agriculture and industry to optimize its benefits while minimizing health risks. A multidisciplinary approach is advocated to enhance agricultural productivity and ensure public health safety.

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Abe, Keita, Yuji Chiba e Yuzo Nishida. "Facile Uptake of Manganese(III) by Apo- Transferrin: Possible Origin of Manganism". Zeitschrift für Naturforschung C 63, n. 1-2 (1 febbraio 2008): 154–56. http://dx.doi.org/10.1515/znc-2008-1-228.

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We have investigated the mechanism of manganese ion uptake by apo-transferrin using a capillary electrophoresis method, and obtained clear evidence that oxidation state +3 and the binuclear unit of a manganese chelate are essential factors for the facile uptake by apotransferrin, similar to that observed for Fe(III) chelates. These results may give valuable information to understand the pathogenesis of manganism and to develop new countermeasures for the neurotoxicity by manganese ions.

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Liu, Winnie, Jihua Hao, Evert J. Elzinga, Piotr Piotrowiak, Vikas Nanda, Nathan Yee e Paul G. Falkowski. "Anoxic photogeochemical oxidation of manganese carbonate yields manganese oxide". Proceedings of the National Academy of Sciences 117, n. 37 (31 agosto 2020): 22698–704. http://dx.doi.org/10.1073/pnas.2002175117.

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The oxidation states of manganese minerals in the geological record have been interpreted as proxies for the evolution of molecular oxygen in the Archean eon. Here we report that an Archean manganese mineral, rhodochrosite (MnCO3), can be photochemically oxidized by light under anoxic, abiotic conditions. Rhodochrosite has a calculated bandgap of about 5.4 eV, corresponding to light energy centering around 230 nm. Light at that wavelength would have been present on Earth’s surface in the Archean, prior to the formation of stratospheric ozone. We show experimentally that the photooxidation of rhodochrosite in suspension with light centered at 230 nm produced H2 gas and manganite (γ-MnOOH) with an apparent quantum yield of 1.37 × 10−3 moles hydrogen per moles incident photons. Our results suggest that manganese oxides could have formed abiotically on the surface in shallow waters and on continents during the Archean eon in the absence of molecular oxygen.

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Majewski, Michal, Karolina Piwko, Michal Ordak, Elzbieta Muszynska, Tadeusz Nasierowski e Magdalena Bujalska-Zadrozny. "Magnetic Resonance Imaging and Manganism: A Narrative Review and Laboratory Recommendations". Journal of Clinical Medicine 13, n. 10 (10 maggio 2024): 2823. http://dx.doi.org/10.3390/jcm13102823.

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In recent years, a series of articles has been published concerning magnetic resonance imaging (MRI) studies in a group of patients exposed to manganism, specifically factory workers, welders, and individuals with liver diseases, as well as those abusing home-produced ephedrone. Some potential symptoms of manganese toxicity include motor disturbances, neurocognitive problems, sleep disorders, and psychosocial changes. Despite various publications on MRI research in individuals with an elevated risk of manganism, there is a noticeable absence of a comprehensive review in this field. The detection of the accumulation of manganese in the brain through MRI can confirm the diagnosis and guide appropriate treatment. Due to the high cost of determining manganese ion levels in biological material, an additional aim of the manuscript was to identify simple medical laboratory parameters that, when performed concurrently with MRI, could assist in the diagnosis of manganism. Among these types of parameters are the levels of bilirubin, magnesium, liver enzymes, creatinine, hemoglobin, and hematocrit.

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Odularu, Ayodele Temidayo. "Manganese Schiff Base Complexes, Crystallographic Studies, Anticancer Activities, and Molecular Docking". Journal of Chemistry 2022 (24 agosto 2022): 1–19. http://dx.doi.org/10.1155/2022/7062912.

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Choice of ligands is significant to successful synthesis of metal complexes (coordination compounds). This study reports the use of Schiff base as the right ligand to control the poor bioavailability and neurodegenerative toxicity challenges of manganese ion. In line with this study, document analysis was used as the methodological approach to evaluate the significance of Schiff base ligands in easing these manganese’s challenges and aligning the resultant coordination compounds (manganese Schiff base complexes) as therapeutic agents in anticancer studies. Report also involves crystallographic studies where single crystal X-ray crystallography was used as a chemical characterization technique. In addition, molecular docking studies, MOE2008, and AutoDock software were used to reveal the mode of interaction between the Schiff base and the manganese(II) and (III) ions, as well as scrutinizing the biological efficacy of the manganese(II) and manganese(III) Schiff bases coordination compounds as anticancer agents against some anticancer cell lines. Conclusion drawn was that manganese(II) and manganese(III) Schiff bases coordination compounds gave more active and potent activities than the corresponding Schiff bases. As a result, challenges of neurodegenerative toxicity and poor bioavailability of manganese ion were overcome, and the chelation therapy was fulfilled. Results from single crystal X-ray crystallography confirmed the successful synthesis of manganese(II) and manganese(III) Schiff bases coordination compounds and revealed the mechanism of reaction, while the molecular docking buttressed the biological activities of the Schiff base ligand and manganese Schiff base coordination compounds by portraying the structure activity relationship (SAR) between either Schiff base or the manganese Schiff base coordination compounds and the virtual cancer cell line (receptor protein), where hits were obtained for lead optimizations.

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Lachowicz, Joanna Izabela, Valeria Marina Nurchi, Guido Crisponi, Ilaria Cappai, Rosita Cappai, Matteo Busato, Andrea Melchior et al. "para-Aminosalicylic acid in the treatment of manganese toxicity. Complexation of Mn2+ with 4-amino-2-hydroxybenzoic acid and its N-acetylated metabolite". New Journal of Chemistry 42, n. 10 (2018): 8035–49. http://dx.doi.org/10.1039/c7nj04648k.

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Sobańska, Zuzanna, Joanna Roszak, Kornelia Kowalczyk e Maciej Stępnik. "Applications and Biological Activity of Nanoparticles of Manganese and Manganese Oxides in In Vitro and In Vivo Models". Nanomaterials 11, n. 5 (22 aprile 2021): 1084. http://dx.doi.org/10.3390/nano11051084.

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The expanding applications of nanotechnology seem to be a response to many technological, environmental, and medical challenges. The unique properties of nanoparticles allow for developing new technologies and therapies. Among many investigated compounds is manganese and its oxides, which in the form of nanoparticles, could be a promising alternative for gadolinium-based contrast agents used in diagnostic imaging. Manganese, which is essential for living organisms as an enzyme cofactor, under excessive exposure—for example, due to water contamination or as an occupational hazard for welders—can lead to neurological disorders, including manganism—a condition similar to Parkinson’s disease. This review attempts to summarise the available literature data on the potential applications of manganese and manganese oxide nanoparticles and their biological activity. Some of the published studies, both in vitro and in vivo, show negative effects of exposure to manganese, mainly on the nervous system, whereas other data suggest that it is possible to develop functionalised nanoparticles with negligible toxicity and novel promising properties.

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Lu, Chung-Hsin, e Shang-Wei Lin. "Dissolution Kinetics of Spinel Lithium Manganate and its Relation to Capacity Fading in Lithium Ion Batteries". Journal of Materials Research 17, n. 6 (giugno 2002): 1476–81. http://dx.doi.org/10.1557/jmr.2002.0219.

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The dissolution behavior and kinetics of spinel lithium manganate LiMn2O4 with different particle sizes have been investigated in this study. The dissolution of manganese cations from LiMn2O4 is confirmed to occur when LiMn2O4 particles are immersed in the electrolytes. The amount of dissolved manganese ions markedly increases with a rise in temperature and a decrease in particle size, which implies that the capacity fading of LiMn2O4 at elevated temperatures is associated with manganese dissolution. On the basis of the isothermal analysis of reaction kinetics, the rate of manganese dissolution from LiMn2O4 is dominated by the rate of dissolution reaction. Smaller particles exhibit a larger reaction rate constant and higher activation energy of the dissolution process than the larger ones. Therefore, an increase in temperature has a more pronounced effect on the dissolution reaction of small particles than on that of large particles.

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Freitas, Regeane M., Thomaz A. G. Perilli e Ana Claudia Q. Ladeira. "Oxidative Precipitation of Manganese from Acid Mine Drainage by Potassium Permanganate". Journal of Chemistry 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/287257.

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Although oxidative precipitation by potassium permanganate is a widely recognised process for manganese removal, research dealing with highly contaminated acid mine drainage (AMD) has yet to be performed. The present study investigated the efficiency of KMnO4in removing manganese from AMD effluents. Samples of AMD that originated from inactive uranium mine in Brazil were chemically characterised and treated by KMnO4at pH 3.0, 5.0, and 7.0. Analyses by Raman spectroscopy and geochemical modelling using PHREEQC code were employed to assess solid phases. Results indicated that the manganese was rapidly oxidised by KMnO4in a process enhanced at higher pH. The greatest removal, that is, 99%, occurred at pH 7.0, when treated waters presented manganese levels as low as 1.0 mg/L, the limit established by the Brazilian legislation. Birnessite (MnO2), hausmannite (Mn3O4), and manganite (MnOOH) were detected by Raman spectroscopy. These phases were consistently identified by the geochemical model, which also predicted phases containing iron, uranium, manganese, and aluminium during the correction of the pH as well as bixbyite (Mn2O3), nsutite (MnO2), pyrolusite (MnO2), and fluorite (CaF2) following the KMnO4addition.

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Devereux, Michael, Malachy McCann, Vanessa Leon, Majella Geraghty, Vickie McKee e Jan Wikaira. "Synthesis and Biological Activity of Manganese (II) Complexes of Phthalic and Isophthalic Acid: X-Ray Crystal Structures of [Mn(ph)(Phen)2(H2O)]· 4H2O, [Mn(Phen)2(H2O)2]2(Isoph)2(Phen)· 12H2O and {[Mn(Isoph)(bipy)]4· 2.75biby}n(phH2 = Phthalic Acid; isoph = Isophthalic Acid; phen = 1,10-Phenanthroline; bipy = 2,2-Bipyridine)". Metal-Based Drugs 7, n. 5 (1 gennaio 2000): 275–88. http://dx.doi.org/10.1155/mbd.2000.275.

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Manganese(II) acetate reacts with phthalic acid (phH2) to give [Mn(ph)]·0.5H2O (1). Reaction of 1 with 1,10-phenanthroline produces [Mn(ph)(phen)]·2H2O (2) and [Mn(ph)(phen)2(H2O)]·4H2O (3). Reaction of isophthalic acid (isophH2) with manganese(II) acetate results in the formation of [Mn(isoph)]·2H2O (4). The addition of the N,N-donor ligands 1,10-phenanthroline or 2,2'-bipyridine to 4 leads to the formation of [Mn2 (isoph)2(phen)3)]·4H2O (5), [(Mn(phen)2(H2O)2]2(isoph)2(phen)·12H2O (6) and {[Mn(isoph)(bipy)]4·2.75 biby}n (7), respectively. Molecular structures of 3, 6 and 7 were determined crystallographically. In 3 the phthalate ligand is bound to the manganese via just one of its carboxylate groups in a monodentate mode with the remaining coordination sites filled by four phenanthroline nitrogen and one water oxygen atoms. In 6 the isophthalates are uncoordinated with the octahedral manganese center ligated by two phenanthrolines and two waters. In 7 the Isophthalate ligands act as bridges resulting in a polymeric structure. One of the carboxylate groups is chelating a single manganese with the other binding two metal centres in a bridging bidentate mode. The phthalate and isophthalate complexes, the metal free ligands and a number of simple manganes salts were each tested for their ability, to inhibit the growth of Candida albicans. Only the “metal free” 1,10-phenanthroline and its manganese complexes were found to be active.

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S, Opoola S., e Ajibade A. J. "Neurotoxic Effects of Manganese Chloride on the Cerebellar Cortex of Adult Wistar Rats". EAS Journal of Pharmacy and Pharmacology 5, n. 03 (23 maggio 2023): 49–57. http://dx.doi.org/10.36349/easjpp.2023.v05i03.002.

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Manganese is a naturally occurring element and an essential nutrient. It is an essential trace metal that is involved in bone formation, brain development and in the metabolism of carbohydrates, cholesterol and amino acids. Excessive exposure of humans to manganese can result in a neurologic and psychological disorder called Manganism. This study assesses the effect of Manganese on the cerebellar cortex of adult wistar rats. Thirty-six (36) adult wistar rats were picked at random and divided into 4 groups with 9 animals each. Group A which was the control received distilled water, group B, group C and Group D received orally 0.3 mg/kg, 0.6 mg/kg and 0.8 mg/kg body weight of Manganese Chloride respectively for 29 days. Experimental Animals were sacrificed on the 30th day by cervical dislocation. The cerebellum were collected after sacrifice, weighted and fixed in 10% formol calcium and subsequently processed for histological observation using Hematoxylin and Eosin staining principle. Part of the cerebella cortex was homogenized for MDA, NO and SDH analysis. The result shows that the mean body weights decreased significantly in the manganese- treated groups when compared to the control. The mean brain weight of the Manganese Chloride treated groups B, C and D Insignificantly Increased compared with the control. Biochemical analysis of the MDA (Lipid Peroxide), NO (Nitric Oxide) and SDH (Succinate Dehydrogenase) Increased Significantly (P<0.05) in the Manganese treated group compare with the control. Histological analysis showed loss and degenerated neurons particularly the Purkinje cells in the cortical layers of the Manganese treated groups compare with normal Cerebella histoarchitecture in the control. This study concluded that Wistar rats treated with Manganese Chloride demonstrated neurodegenerative changes in the cerebella cortical layers, which may adversely affect some cerebella functions in the Wistar rats investigated.

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20

Krupińska, Izabela. "The Impact of Potassium Manganate (VII) on the Effectiveness of Coagulation in the Removal of Iron and Manganese from Groundwater with an Increased Content of Organic Substances". Civil and Environmental Engineering Reports 27, n. 4 (20 dicembre 2017): 29–41. http://dx.doi.org/10.1515/ceer-2017-0048.

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Abstract The article presents the results of studies concerning the impact of the method of Fe(II) ion oxidisation (dissolved oxygen and potassium manganate (VII)) on the effectiveness of coagulation in the removal of iron and manganese from groundwater with an increased content of organic substances. The efficiencies of two coagulants were compared: aluminium sulphate (VI) and polyaluminium chloride (Flokor 1.2A). Among the used methods of iron (II) oxidisation, the best effects have been achieved by potassium manganate (VII) because one of the oxidation products was manganese oxide (IV) precipitating from water. Better results in purifying the water were obtained with the use of a prehydrolysed coagulant Flokor 1.2 A than aluminium sulphate (VI).

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21

Firouzabadi, Habib, Babak Karimi e Mohammad Abbassi. "Efficient Solvent-free Oxidation of Benzylic and Aromatic Allylic Alcohols and Biaryl Acyloins by Manganese Dioxide and Barium Manganate". Journal of Chemical Research 23, n. 3 (marzo 1999): 236–37. http://dx.doi.org/10.1177/174751989902300333.

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22

Pereira, Luciano Almeida, Simone Soares de O. Borges, Maurício Costa Castro, Waldomiro Borges Neto, Cláudia Carvalhinho Windmöller e José Bento Borba da Silva. "Determination of manganese and nickel in slurry sampling by graphite furnace atomic absorption spectrometry". Canadian Journal of Chemistry 86, n. 4 (1 aprile 2008): 312–16. http://dx.doi.org/10.1139/v08-019.

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Methods for the determination of manganese and nickel in lake and marine sediment slurries by graphite furnace atomic absorption spectrometry using permanent modifiers are proposed. The slurries were maintained homogeneous with air bubbling with an aquarium pump. For manganese, the best modifier was ruthenium permanent with mo of 0.9 pg and of 1.0, 1.2, 1.5, and 1.8 pg, for Rh, without modifier, Ir, and Zr, respectively. For nickel, the best modifier was rhodium permanent with mo of 33 pg, followed by 85, 120, 132, and 240 pg, without modifier, Zr, Ir, and Ru, respectively. After determining manganese and nickel in two certified marine sediment samples (n = 10) from NRCC, PACS-2, and MESS-2, and in the San Joaquin 2079 soil, the results agreed at the confidence level of 95% with the certified value for all analytes studied using aqueous calibration. Calibration curves of all analytes had correlation coefficients R2 higher than 0.99. Recovery studies made in four levels for each analyte in sediments from Lake Pampulha showed acceptable values. The limits of detection (LODs) were 4.0 and 0.9 µg L-1 for manganese and nickel, respectively.Key words: manganse, nickel, sediments, GF AAS.

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23

Azimova, G. R. "STUDY OF LOW-TEMPERATURE OXIDATION OF CARBON MONOOXIDE ON Cu–Mn–Fe CATALYTIC OXIDE SYSTEMS OBTAINED BY THE SOL-GEL COMBUSTION METHOD". Azerbaijan Chemical Journal, n. 2 (2 giugno 2022): 93–99. http://dx.doi.org/10.32737/0005-2531-2022-2-93-99.

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The oxidation of carbon monoxide was studied on oxide Cu–Mn–Fe catalytic systems with metal ratio Cu:Mn:Fe=1:1:1; 2:1:1; 1:2:1 and 1:1:2 obtained by the sol-gel method with combustion. The results of X-ray phase analysis showed that the catalytic systems have a complex phase composition. Along with double oxides of manganese and iron, ferrites of copper-, manganese, copper manganite, manganese-substituted copper ferrites were formed (CuFe2O4; Mn0.43Fe2.57O4, Mn0.98Fe2.02O4; CuMn2O4; Cu1.2Mn1.8O4; Cu0.5Mn0.5Fe2O4). It has been found that depending on the ratio of metals in the catalyst, the reaction start temperature is in the temperature range of 120–1700C. And after 3–5 minutes after the start of the reaction, the conversion begins to increase sharply, reaching 100% within the next 5 minutes

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24

Kuźniarska-Biernacka, I., A. Lisinska-Czekaj, D. Czekaj, M. José Alves, A. Mauricio Fonseca e I. Correia Neves. "Styrene Epoxidation Over Heterogeneous Manganese(III) Complexes". Archives of Metallurgy and Materials 61, n. 3 (1 settembre 2016): 1477–82. http://dx.doi.org/10.1515/amm-2016-0242.

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Abstract The manganes(III) complex functionalised with 2,3-dihydropyridazine has been encapsulated in the supercages of the NaY zeolite using two different procedures, flexible ligand and in situ complex. The parent zeolite and the encapsulated manganese(III) complexes were screened as catalysts for styrene oxidation by using t-BOOH as the oxygen source in acetonitrile. Under the optimized conditions, the catalysts exhibited moderate activity with high selectivity to benzaldehyde

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25

Chakraborty, D., e T. K. Baidya. "Multi-Phase Manganese Mineralization in the Noamundi Synclinorium, East Indian Shield". Energy and Earth Science 3, n. 1 (7 maggio 2020): p26. http://dx.doi.org/10.22158/ees.v3n1p26.

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Manganese mineralization associated with phyllites in and around Joda, Odisha belongs to the Iron Ore Group of Noamundi basin and is a part of Jamda-Koira belt of East Indian Shield. The present study area comprises low to medium grade tectonites containing economic resources of both iron and manganese. Present study is concentrated on Manganese mineralization. Field study and petro-mineralogical observations reveal syngenetic character of manganese ores comprising lowT higher oxides viz. pyrolusite, cryptomelane, manganite as major Mn-minerals along with highT lower oxides viz. jacobsite, bixbyite, braunite and hausmannite as minor Mn-minerals. The Mn-ore bodies and associated phyllites have undergone multiple phases of deformation and metamorphism followed by hydrothermal and supergene processes. Four deformational phases have been deciphered during field study. Geochemical analyses of ores and phyllitic host rocks show high values of Al2O3, TiO2, Ba, Co, Ni, Cr, Cu, Sc, V, As, Zn but depletion of Sr, Yb, Sm, Nb. Geochemical data infer ores to be a recycling product originally derived from a mafic crustal source of tholeiitic character. Age data obtained from Sm-Nd ratio of two rock samples are 3.46 Ga and 2.79 Ga. Present work provides a critical assessment on the multiphase mineralization of manganese ores.

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Nascimento, Lorena Meirelis do, Murilo Farias dos Santos, Clarissa Araújo da Paz, Daniella Bastos de Araújo, Rayllan da Cunha Ferreira, Yris da Silva Deiga, Luana Vasconcelos de Souza et al. "Morphographic Changes in the Electrocardiogram of Colossoma macropomum Caused by Exposure to Manganese". International Journal of Molecular Sciences 25, n. 16 (16 agosto 2024): 8910. http://dx.doi.org/10.3390/ijms25168910.

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Manganese (Mn2+) is an abundant chemical element in the earth’s crust and is present in soil, water, and industrial environments, including mining, welding, and battery manufacturing. Manganese (Mn) is an essential metal needed as a cofactor for many enzymes to maintain proper biological functions. Excessive exposure to Mn in high doses can result in a condition known as manganism, which results in disorders of the neurological, cardiac, and pulmonary systems. The aim of this study was to assess cardiac susceptibility to manganese intoxication in Colossoma macropomum subjected to a fixed concentration of 4 mg/mL for a period of up to 96 h. This study used 45 Tambaquis (30.38 ± 3.5 g) divided into five groups of 9 animals/treatment. The treated groups were exposed to the manganese concentration for a period of 24, 48, 72, and 96 h, after which the animals’ ECGs were recorded, showing heart rate, R-R interval, P-Q interval, QRS complex duration and S-T interval. The results showed that cardiac activity decreased as the contact time increased, with an increase in the P-Q and S-T intervals. This indicates that the breakdown of circulatory homeostasis in these animals was caused by contact time with manganese.

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27

Lee, Sun Hee, Dae Hoon Park, Seong-Ju Hwang e Jin-Ho Choy. "Effect of Copper Doping on the Crystal Structure and Morphology of 1D Nanostructured Manganese Oxides". Journal of Nanoscience and Nanotechnology 7, n. 11 (1 novembre 2007): 4029–32. http://dx.doi.org/10.1166/jnn.2007.080.

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We have tried to control the aspect ratio and physicochemical properties of 1D nanostructured manganese oxides through copper doping. Copper-doped manganese oxide nanostructures have been synthesized by one-pot hydrothermal treatment for the mixed solution of permanganate anions and copper cations. According to powder X-ray diffraction and electron microscopic analyses, all the present materials commonly crystallize with α-MnO2-type structure but their aspect ratio decreases significantly with increasing the content of copper. Such a variation of crystallite dimension is attributable to the limitation of crystal growth by the incorporation of copper ions. X-ray absorption spectroscopic studies at Mn K- and Cu K-edges clearly demonstrate that the average oxidation state of manganese ions is increased by the substitution of divalent copper ions. Electrochemical measurements reveal the improvement of the electrode performance of nanostructured manganate upon copper doping, which can be interpreted as a result of the decrease of aspect ratio and the increase of Mn valence state. From the present experimental findings, it becomes certain that the present Cu doping method can provide an effective way of controlling the crystal dimension and electrochemical property of 1D nanostructured manganese oxide.

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Nicoletti, Alessandra, e Mario Zappia. "Comment on ‘A photoelectron spectroscopy study of lava stones’ by D. A. Cristaldi, C. G. Fortuna and A. Gulino, Anal. Methods, 2013, 5, 3458". Analytical Methods 8, n. 18 (2016): 3847–48. http://dx.doi.org/10.1039/c3ay41326h.

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Exposure to high levels of manganese can cause a form of parkinsonism known as manganism. A higher concentration of MnOOH species on the surface of lapilli from Mount Etna likely results in a high concentration of Mn in groundwater from Etna wells. A possible increased local risk of manganism has been hypothesized. Photograph © Salvatore Giammanco.

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29

Perez-Benito, Joaquin F., e Donald G. Lee. "Oxidation of hydrocarbons. 15. A study of the oxidation of alkenes by methyltributylammonium permanganate". Canadian Journal of Chemistry 63, n. 12 (1 dicembre 1985): 3545–50. http://dx.doi.org/10.1139/v85-582.

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A study of the reduction of methyltributylammonium permanganate by a large number of alkenes in methylene chloride has dispelled a current uncertainty concerning the nature of the inorganic product obtained. It is colloidal manganese dioxide and not a manganate(V) cyclic diester as previously supposed. This product is stabilized in methylene chloride solutions by adsorption of the alkene, which decreases its polarity at the solvent interphase. The solubility of the colloid is therefore a function of both the concentration and the identity of the alkene. In certain (atypical) cases, where acidic compounds are present, the product is further reduced to manganese(III).

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30

Tofan, Vlad-Constantin, Ştefania-Maria Lascăr e Ioana Berindan-Neagoe. "MANGANESE (II) MODULATES MACROPHAGES IMMUNE RESPONSE TO LIPOPOLYSACCHARIDE". Romanian Archives of Microbiology and Immunology 81, n. 2 (30 giugno 2022): 79–86. http://dx.doi.org/10.54044/rami.2022.02.02.

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Background: Manganese (Mn) impact on human health is often studied regarding its neurotoxicity, leading to a Parkinson-like pathology termed manganism. Since scientific reports indicate manganese neurotoxicity as potentially inflammation-driven, our study aims to investigate the influence of acute and chronic manganese (II) chloride (MnCl2) exposure on macrophages ability to react to an inflammatory stimulus. Methods: The experimental model consisted in in vitro treatment of RAW264.7 murine macrophage-like cells with MnCl2 for two different time intervals in an attempt to simulate acute intoxication and chronic intoxication. Non-cytotoxic MnCl2 concentration values were determined using MTT assay. Acute and chronic exposure to manganese was followed by lipopolysaccharide (LPS) stimulation. Relevant pro-inflammatory cytokine secretion, mRNA transcripts and NF-κB p65 nuclear translocation were measured. Results: LPS stimulation of cells treated with non-cytotoxic MnCl2 levels triggered enhanced TNF-α (Tumor Necrosis Factor α) secretion in the investigated acute model, whereas in the chronic exposure model only an intermediate MnCl2 concentration (37.5 μM) caused a rise in cytokine secretion. Acute treatment induced a dosedependent upregulation of Tnfα and Nos2 (Nitric oxide synthase 2) gene transcription coupled with an increasing trend in nuclear distribution of p65 subunit of NF-κB complex. Chronic treatment induced a dose-dependent downregulation of pro-inflammatory genes alongside an increase in Ho1 (Heme oxygenase 1) transcription. Conclusions: Our results suggest that manganese (II) has the potential to modulate macrophage inflammatory response development. Acute exposure generally intensifies inflammatory processes, while chronic exposure induces an attenuation of these, possibly due to heme oxygenase-1 inhibition of NF-kB signaling. Keywords: Manganese, Inflammation, Lipopolysaccharide, Cytokines, Heme oxygenase 1

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31

&NA;. "Manganese". Reactions Weekly &NA;, n. 1377 (novembre 2011): 24. http://dx.doi.org/10.2165/00128415-201113770-00077.

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32

Aschner, Michael, e David C. Dorman. "Manganese". Toxicological Reviews 25, n. 3 (2006): 147–54. http://dx.doi.org/10.2165/00139709-200625030-00002.

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&NA;. "Manganese". Reactions Weekly &NA;, n. 1154 (giugno 2007): 17. http://dx.doi.org/10.2165/00128415-200711540-00055.

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34

Aschner, Michael, e Keith Erikson. "Manganese". Advances in Nutrition: An International Review Journal 8, n. 3 (maggio 2017): 520–21. http://dx.doi.org/10.3945/an.117.015305.

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35

FREELAND-GRAVES, JEANNE H. "Manganese". Nutrition Today 23, n. 6 (novembre 1988): 13–19. http://dx.doi.org/10.1097/00017285-198811000-00004.

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36

Barceloux, Donald G., e Donald Barceloux. "Manganese". Journal of Toxicology: Clinical Toxicology 37, n. 2 (gennaio 1999): 293–307. http://dx.doi.org/10.1081/clt-100102427.

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37

GREGER, J. L., e ELISE A. MALECKI. "Manganese". Nutrition Today 32, n. 3 (maggio 1997): 116–21. http://dx.doi.org/10.1097/00017285-199705000-00004.

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38

Warrens, C. P. "Manganese". Coordination Chemistry Reviews 71 (agosto 1986): 3–36. http://dx.doi.org/10.1016/0010-8545(86)80019-4.

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39

Turp, N. "Manganese". Coordination Chemistry Reviews 72 (ottobre 1986): 197–294. http://dx.doi.org/10.1016/0010-8545(86)80030-3.

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40

Jomaron, C. M., M. M. Dworetsky e C. S. Allen. "Manganese abundances in mercury--manganese stars". Monthly Notices of the Royal Astronomical Society 303, n. 3 (1 marzo 1999): 555–64. http://dx.doi.org/10.1046/j.1365-8711.1999.02252.x.

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41

Denecke, Melissa A., W. Gunßer, G. Buxbaum e P. Kuske. "Manganese valence in precipitated manganese ferrite". Materials Research Bulletin 27, n. 4 (aprile 1992): 507–14. http://dx.doi.org/10.1016/0025-5408(92)90029-y.

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42

Carvalho, Glauber Miranda de, Hélio Marcos Fernandes Viana, Rubem Xerxes Trindade Rodrigues, João Paulo Freire Rocha e Gilson Rodrigues Junior. "DESEMPENHO RODOVIÁRIO LABORATORIAL DO RESÍDUO DE MINERAÇÃO DE MANGANÊS DE LICÍNIO DE ALMEIDA - BA QUANDO MISTURADO COM A BRITA 1". Revista Eletrônica de Gestão e Tecnologias Ambientais 9, n. 1 (26 aprile 2021): 99. http://dx.doi.org/10.9771/gesta.v9i1.38452.

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Abstract (sommario):

O presente trabalho avaliou o comportamento do CBR, na energia intermediária de Proctor, quando são adicionadas porcentagens de 30%, 50% e 75% de brita 1, em massa, ao rejeito de manganês que foi coletado na região do município de Licínio de Almeida. O objetivo foi encontrar uma mistura que atendesse satisfatoriamente aos requisitos do Departamento Nacional de Infraestrutura de Transportes (DNIT) estabelecidos em 2006 para construção de base de pavimentos rodoviários. Os ensaios laboratoriais realizados na energia intermediária de Proctor verificaram a eficiência de cada uma das misturas a partir dos valores de CBR e de sua expansão observados. Com base nos modelos estatísticos desenvolvidos, este trabalho constatou que uma mistura de rejeito de manganês-brita 1, com apenas 39,5% de teor de brita 1, em massa, atende às referidas exigências. A conclusão do trabalho destaca que a adição de um baixo teor de brita 1, em massa, ao rejeito de manganês torna real a possibilidade de obter dois benefícios: combater um problema ambiental e viabilizar de forma altamente qualitativa a construção da base, que é uma das mais importantes camadas do pavimento rodoviário.Palavras-chave: Pavimento; Rejeitos; Manganês; Meio Ambiente LABORATORY ROAD PERFORMANCE OF LICÍNIO DE ALMEIDA (BA) MANGANESE MINING WASTE, WHEN MIXED WITH BRITA 1AbstractThis work aimed to use statistical modeling based on mixtures of materials, type of manganese tailings-crushed stone 1 to find a mixture that satisfactorily met the requirements of the DNIT (National Department of Transport Infrastructure) for the construction of a road pavement base. The crushed stone composed the studied mixtures in the contents of 30%, 50% and 75% by mass. Manganese tailings were classified as silty-sand soil (A-4 from TRB, SM from USCS and NA from MCT); Thus, the CBR behavior was evaluated that takes basis on the efficiency of each of the mixture for the intermediate energy of Proctor. Furthermore, based on developed statistical models, it was found that a mixture of manganese-crushed stone 1, with only 39.5% of gravel content, by mass, it was possible to meet the requirements of the DNIT (2006) for base construction of road pavements. Finally, with the addition of a low content of crushed stone 1, in mass, to the manganese tailings, the possibility of obtaining two benefits is real: to combat an environmental problem and to make possible the construction of the base, which is one of the most important road pavement layers.Keywords: Pavement; Tailings; Manganese; Environment

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43

Polgári, Márta, Marc Philippe, Magda Szábo-Drubina e Mária Tóth. "Manganese-impregnated wood from a Toarcian manganese ore deposit, Epleny mine, Bakony Mts., Transdanubia, Hungary". Neues Jahrbuch für Geologie und Paläontologie - Monatshefte 2005, n. 3 (17 marzo 2005): 175–92. http://dx.doi.org/10.1127/njgpm/2005/2005/175.

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44

Nielsen, Brian S., Erik H. Larsen, Ole Ladefoged e Henrik R. Lam. "Subchronic, Low-Level Intraperitoneal Injections of Manganese (IV) Oxide and Manganese (II) Chloride Affect Rat Brain Neurochemistry". International Journal of Toxicology 36, n. 3 (maggio 2017): 239–51. http://dx.doi.org/10.1177/1091581817704378.

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Abstract (sommario):

Manganese (Mn) is neurotoxic and can induce manganism, a Parkinson-like disease categorized as being a serious central nervous system irreversible neurodegenerative disease. An increased risk of developing symptoms of Parkinson disease has been linked to work-related exposure, for example, for workers in agriculture, horticulture, and people living near areas with frequent use of Mn-containing pesticides. In this study, the focus was placed on neurochemical effects of Mn. Rats were dosed intraperitoneally with 0.9% NaCl (control), 1.22 mg Mn (as MnO2)/kg bodyweight (bw)/day, or 2.5 mg Mn (as MnCl2)/kg bw/day for 7 d/wk for 8 or 12 weeks. This dosing regimen adds relevant new knowledge about Mn neurotoxicity as a consequence of low-dose subchronic Mn dosing. Manganese concentrations increased in the striatum, the rest of the brain, and in plasma, and regional brain neurotransmitter concentrations, including noradrenaline, dopamine (DA), 5-hydroxytrytamine, glutamate, taurine, and γ-amino butyric acid, and the activity of acetylcholinesterase changed. Importantly, a target parameter for Parkinson disease and manganism, the striatal DA concentration, was reduced after 12 weeks of dosing with MnCl2. Plasma prolactin concentration was not significantly affected due to a potentially reduced dopaminergic inhibition of the prolactin release from the anterior hypophysis. No effects on the striatal α-synuclein and synaptophysin protein levels were detected.

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Adeoye, Akintola Ojo, Najime Tavershima, Danladi Bello Abubakar, Ogunleye Paul Olusegun e Abubakar Ismail Yusuf. "Petrochemical Features of Manganese Nodules in Madaka (Sheet 142) SE and Part of Kwana - Bala (Sheet 142) NE, Nigeria". Sumerianz Journal of Scientific Research, n. 43 (24 luglio 2021): 52–59. http://dx.doi.org/10.47752/sjsr.43.52.59.

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Manganese nodule occurs in Madaka (Sheet 142) SE and part of Kwana - Bala (Sheet 142) NE, Nigeria. Four (4) samples of manganese nodules were analyzed petrochemical using X-ray diffractometry (XRD), reflected light microscopy, Electron probe micro analysis (EPMA), Atomic absorption spectrophotometer (AAS). XRD reveals sphalerite, manganates and ilmenite as major minerals in the nodules. Accessory minerals are siderite and rutile. Chemical study of the manganese nodules from Madaka and Kwana - Bala reveals that Mn-, Fe-, Co-, Ni-, and Cu-, minerals (including native elements and sulfides) commonly occur in the samples. Also, the results indicate that increased in Mn relative to the manganite content (10AO- plus 7AO), led to increase in Ni and Cu recovery. However, slightly greater amounts by weight of Ni and Cu were dissolved from the manganites than from Mn. This followed from the much higher Ni and Cu contents of manganites relative to Mn. The exploration for Ni and Cu from nodules on assay criterion was inadequate; the sphalerite Mn02 phase structure would also be a necessary criterion. It was suggested that nodules could be processed upon beneficiation for Ni and Cu contents for a future time relative to the original processing. It was thus proposed that Ni and Cu could be produced from manganese nodules in the study area.

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46

Matsuda, A., M. Kimura, M. Kataoka, S. Ohkuma, M. Sato e Y. Itokawa. "Quantifying manganese in lymphocytes to assess manganese nutritional status." Clinical Chemistry 35, n. 9 (1 settembre 1989): 1939–41. http://dx.doi.org/10.1093/clinchem/35.9.1939.

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Abstract To clarify whether manganese nutritional status is better reflected by the manganese concentration in lymphocytes or in whole blood, we injected manganese solutions intravenously into manganese-deficient rats and determined manganese concentrations in lymphocytes, whole blood, and various tissues. The manganese concentrations in lymphocytes and tissues, but not in whole blood, were significantly less in manganese-deficient rats than in normal rats. These low values could be prevented by intravenous injection of manganese in a dose-dependent manner. These results suggest that, for assessment of manganese nutritional status, measurement of manganese in lymphocytes is better than that in whole blood.

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Tan, Juanjuan, Shida Gong, Jianming Deng, Qianshu Li, Qiong Luo, Yaoming Xie e R. Bruce King. "Energetic preference of dative fluorine manganese bonds over direct manganese manganese bonds in binuclear hexafluorocyclopentadiene manganese carbonyls". Journal of Fluorine Chemistry 188 (agosto 2016): 50–57. http://dx.doi.org/10.1016/j.jfluchem.2016.06.003.

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48

Zhao, Fu-Wang, Xing Li e Nigel Graham. "The application of potassium manganate in water treatment". Water Supply 11, n. 5 (1 dicembre 2011): 612–20. http://dx.doi.org/10.2166/ws.2011.023.

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This paper explores the feasibility of using potassium manganate (K2MnO4) in water treatment. Manganate (Mn(VI)), like ferrate (Fe(VI)), can act as both an oxidant and a coagulant/adsorbent arising from the formation of insoluble manganese dioxide (Mn(IV)) from the chemical reduction of MnO42−. In this paper the basic properties of K2MnO4 are described, including the standard electrode potential which exceeds several oxidizing agents commonly used as water treatment chemicals. The methods of preparing K2MnO4 are outlined, and the main reaction products, which are potassium permanganate (KMnO4) and manganese dioxide (MnO2), and their use in water treatment are summarized. Some preliminary results of water treatment tests in China and at Imperial College London are presented, and alternative ways of applying K2MnO4 in water treatment are proposed. Finally, the paper provides a preliminary evaluation of the economic feasibility of using K2MnO4 in comparison with alternative chemicals, such as KMnO4. Overall, it is believed that K2MnO4 may be a useful water treatment chemical in the future.

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Ayotte, Pierre, e Gabriel L. Plaa. "Hepatic subcellular distribution of manganese in manganese and manganese-bilirubin induced cholestasis". Biochemical Pharmacology 34, n. 21 (novembre 1985): 3857–65. http://dx.doi.org/10.1016/0006-2952(85)90435-6.

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50

Yang, Wen Qiang, Juan An, Xiao Li Yuan e Wen Tang Xia. "Manganese Removal from Electrolytic Manganese Residue Using Ozone". Advanced Materials Research 997 (agosto 2014): 754–57. http://dx.doi.org/10.4028/www.scientific.net/amr.997.754.

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This paper deals with experimental investigations related to removal of manganese (II) from electrolytic manganese residues by using ozone as oxidant. Ozone was used in this study to oxidize manganese converting bivalent manganese to high valence states, the oxidized salts will precipitate as manganese oxides, that to reach the concentration of the pollutant under its limit values in water. Effects of reaction temperature, reaction contact time and initial pH value on the manganese (II) removal were investigated. The results indicated that the removal rate exceeded 99.9 percent, and the manganese (II) in solution was lower than 0.1 mg·L-1 under the conditions of reaction temperature 45 °C, reaction contact time 40 min and initial pH 12.

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