Gold nanoclusters (AuNCs) with fluorescence in the Near Infrared (NIR) by both one- and two-photon electronic excitation were incorporated in mesoporous silica nanoparticles (MSNs) using a novel one-pot synthesis procedure where the condensation polymerization of alkoxysilane monomers in the presence of the AuNCs and a surfactant produce hybrid MSNs of 49 nm diameter. This method was further developed to prepare 30 nm diameter nanocomposite particles with simultaneous NIR fluorescence and superparamagnetic properties, with a core composed of superparamagnetic manganese ferrite nanoparticles (MnFe2O4) coated with a thin silica layer, and a shell of mesoporous silica decorated with AuNCs. The nanocomposite particles feature NIR-photoluminescence with 0.6% quantum yield and large Stokes shift (290 nm), and superparamagnetic response at 300 K, with a saturation magnetization of 13.4 emu g-1. The conjugation of NIR photoluminescence and superparamagnetic properties in the biocompatible nanocomposite has high potential for application in multimodal bioimaging.

Plastics, primarily microplastics, are among the greatest pollutants in aquatic environments. Their removal and/or degradation in these environments are crucial to ensure an optimal future of the ecosystems. In this work MnO2 particles were synthesized and characterized for the removal polystyrene microplastics as a model. MnO2 catalyzes the peroxide reaction, resulting in the formation of oxygen bubbles that propel the pollutants to the surface, achieving removal efficiencies of up to 80%. To achieve this, hydrothermal synthesis was employed using various methods. Parameters such as MnO2, microplastics and H2O2 concentrations were varied to determine the optimal conditions for microplastics recovering. The ideal conditions for a low microplastic concentrations of microplastics (10 g L-1) are 0.2 g L-1 MnO2, 1.6% of H2O2 and 0.01 triton as a surfactant. In these conditions the micromotors can recover approximately of 80% 300 nm sized polystyrene microplastic within 40 min.

In recent years cultivated soils have been increasingly supplemented with nutrients that at low doses are necessary for proper plant functioning but become toxic at high doses. New methods are needed to prevent these destructive actions, and for this reason we studied the effects of two elements – Mn treated as a stressor and Se treated as a potential defense in two wheat cultivars. The intensity of stress was manifested in tissue browning and weight reduction and was determined by an increase in lipid peroxidation and quantitative analysis of hydrogen peroxide levels. It was found that the excess of Mn in the substrate caused more intense changes in these indicators in the root system than in the leaves, and that Se presence partly eliminated the stress evoked effects. Moreover, Mn-treatment was accompanied by a greater absorption of this element by the roots, and a reduced uptake of other elements (K, Fe, S, P), with the exception of Ca, an increase in which was observed especially in the additional presence of Se. It was suggested that the rise in Ca level can lead to modification of cell differentiations and may be one of the steps in defense mechanisms. The change in the direction of cell differentiation in the apical part of the root was observed microscopically under Mn stress and was accompanied by a quantitative increase in 5-met C. Based on DNA methylation profiles detected by MSAP we concluded that various types of methylation sites may be activated under Mn treatment in roots.

Manganese sludge, an industrial waste in the ferroalloy industry, contains various components and holds significant importance for sustainable development through its valorization. This study focuses on characterizing a manganese sludge and investigating its behavior during sulfuric acid leaching. The influence of process conditions, including temperature, acid concentration, liquid to solid ratio, and leaching duration, was examined. The results revealed that Mn, Zn, and K are the main leachable components, and their leaching rates increase with increasing temperature, liquid to solid ratio, and time. However, acid concentration requires optimization. High leaching rates of 90% for Mn, 90% for Zn, and 100% for K were achieved. Moreover, it was found that Pb in the sludge is converted to sulfate during the leaching which yields a sulfate concentrate rich in PbSO4. The leaching process for Mn and Zn species appears to follow a second or -third order reaction, and the calculation of rate constants indicated that Mn leaching kinetics are two to five times higher than those for Zn. Thermodynamic calculations were employed to evaluate the main chemical reactions occurring during leaching.

The objective of this work is the study the crystal structure and elemental content of braunite-hematite and braunite-psilomelane oxide manganese ores y means of X-ray diffractometry (XRD), Energy Dispersion X-ray (EDX) analysis, and X-Ray fluorescent (XRF) analysis. It was found that heat treatments at 600, 800, and 1000 °C promote the phase transitions of the manganese ores to the formation of thermostable phases hausmannite and bixbyite without change in the metallic composition. The homogeneity of the structure increases with increasing temperature, which is expressed in the decreasing of the Mn content in the EDX spectra after sintering above 800 °C as well as in a decrease of the phase number to only two phases: bixbyite and quartz. Remarkably, the hausmannite phase is obtained in the fraction of 61% after sintering the braunite-hematite ore sample at 1000 °C for 4 h. Since hausmannite is widely used to produce building materials, electrodes, catalysts, and other materials, these results are promising for developing technologies for obtaining new products based on phases of manganese minerals at high temperatures.

High levels of groundwater containing both arsenic and fluorine are prevalent, resulting in serious health problems when consumed as drinking water. This co-pollution phenomenon is widespread and requires urgent attention. The multiple forms of arsenic and arsenic-fluorine co-contamination pose a significant challenge to efficiently co-remove both substances. This research utilized a green and stable synthesis approach to create MgLaFe LDO heterostructures, which were anchored on α-MnO2 nanowires. The materials comprise magnesium and lanthanum elements with a powerful attraction towards fluoride ions, elemental iron, which can establish stable compounds with arsenate, and MnO2, which can effectively oxidize arsenous acid, thereby enabling efficient co-removal of arsenic and fluorine. The efficient oxidation process of the MnO2 nanowire and the prompt ion adsorption process of the LDO work together synergistically. The adsorption performance was assessed through isotherm and kinetic fitting. Chemisorption was found to be the process for As(Ⅲ), As(V), and F- adsorption, with As(Ⅲ) going through monolayer adsorption on the surface of MnO2 nanowires, while As(V) and F- were mainly adsorbed by multilayer process on LDO. The maximum adsorption capacities were 111.76 mg/g, 230.51 mg/g, and 765.10 mg/g for As(Ⅲ), As(V), and F-, respectively. The XPS analysis provided further elucidation on the adsorption mechanism of the MnO2@LDO heterostructure, detailing each component's role in the process. The results confirm the successful construction of the heterostructure and its efficient coupling of oxidation and adsorption.

Filamentous manganese (Mn) oxide particles, which occur in the suboxic zone of stratified waterbodies, are important drivers of diverse elemental cycles. Although these particles are considered to be bacteriogenic, the environmental factor responsible for their formation has not been identified. Based on this study of laboratory cultures of a model Mn(II)-oxidizing bacterium, the supply of algal extracellular polymeric substances (EPS) was shown to stimulate Mn(II) oxidation and thus the production of filamentous Mn oxide particles. This observation was consistent with results obtained for naturally occurring particles collected from a near-bottom layer (depth of ~90 m) in the northern basin of Lake Biwa, Japan, that is, most Mn particles resembling delta-MnO2 were associated with an EPS-like gelatinous matrix, which contained dead algal cells and was lectin-stainable. In the lake water column, EPS produced by photosynthesis sank to the bottom layer. The analysis of the quality of water samples, which have been collected from the study site for 18 years, reveals that the annual average total phytoplankton biovolume in the surface layer correlates with the density of filamentous Mn particles in the near-bottom layer. Among different phytoplankton species, green algae appeared to be the key species. The results of this study suggest that algal EPS production induces the formation of filamentous Mn oxide particles in the near-bottom layer of the northern basin of Lake Biwa.

This study examined the accumulations and transfer of manganese into 11 wild plants from the mining soils of Gümüşköy, Turkey. The greatest silver resource in Turkey is found in the Gümüsköy mining area, which is situated roughly 25 kilometers to the west of Kütahya. ICP-MS was used to determine the Mn contents in soil and plant samples that were taken from the field. In the research area, the average Mn concentrations in the soil, roots, and shoots of wild plants were 1872, 1076, and 1048 ppm, respectively. Based on their ECS and ECR values, the plants were divided into three groups: the best plants, good plants, and candidate plants. While Glaucium flavum, Carduus nutans, Phlomis sp., Onosma sp., and Verbascum thapsus were selected as the best plants, Cynoglossum officinale, Anchusa arvensis were determined as good plants, and the others (Alyssum saxatile, Centaurea cyanus, Silene compacta, Isatis were determined as candidate plants. According to the current study, all of the best and good plants in the study region had a very high ability to remove Mn. As a result, these plants can be helpful in studies involving phytoremediation or remediation of Mn-polluted soil.

OsNRAMP5—a member of the same family as the iron, manganese (Mn), and cadmium (Cd) transporter OsNRAMP1—is responsible for the transport of Mn and Cd from soil in rice. Knockout of OsNRAMP5 markedly reduces both Cd and Mn absorption; therefore, in low -Mn environments, such plants would exhibit Mn deficiency and suppressed growth. Amino acid mutations in IRT1 alter its metal selectivity. We generated random mutations in OsNRAMP5 via error-prone PCR, and used yeast to screen for the retention of Mn absorption and inhibition of Cd absorption. The results showed ththat alanine 512th is the most important amino acid residue for Cd absorption, and that its substitution resulted in the absorption of Mn but not Cd.

Four different Mn and Re catalysts for electrochemical CO2 reduction have been studied by IR spectroelectrochemistry (SEC) in dry acetonitrile. In the case of Mn(apbpy)(CO)3Br (apbpy= 4(4-aminophenyl)-2,2’-bipyridine) SEC suggests that a very slow catalytic reduction of CO2 occurs in acetonitrile also in the absence of proton donors, but at rather negative potentials. On the contrary, the corresponding Re(apbpy)(CO)3Br clearly displays a slow catalytic conversion already at the first reduction potential. Switching to saturated CO2 solutions in a mixture of acetonitrile and 5% of water as proton donor, the SEC of Mn(apbpy)(CO)3Br displays faster catalytic behavior.

The CYSTM (cysteine-rich transmembrane module) protein family comprises small molecular cysteine-rich tail-anchored membrane proteins found in many eukaryotes. The Saccharomyces cerevisiae strains carrying the CYSTM genes YDRO34W-B and YBR056W-A (MNC1) fused with GFP were used to test expression of these genes under different stresses. The YBR056W-A (MNC1) and YDR034W-B genes are expressed under stress conditions caused by the toxic concentrations of heavy metal ions such as manganese, cobalt, nickel, zinc, cuprum, and 2.4-dinitrophenol uncoupler. YDR034W-B but not YBR056W-A is expressed under alkali and cadmium stresses. YBR056W-A is localized in intracellular membranes, while YDR034W-B is localized in the cytoplasmic membrane. The null-mutants in both genes demonstrated both decreased cell concentration and lytic phenotype when cultivated in the presence of excess manganese. This indicates the involvement of Mnc1 and YDR034W-B proteins in manganese detoxification, probably by complexation of its ion.

In this study, Mg-Al and Mg-Al-Ni - layered double hydroxides (LDHs) were successfully synthesized for efficient removal of Mn²⁺ from synthetically wastewater. LDH adsorbents (Mg-Al and Mg-Ni-Al) were prepared by co-precipitation method. The formation of the layered double hydroxide, the adsorption of manganese on both LDH (Mg-Al and Mg-Ni-Al) were observed by XRD, SEM and EDX analysis. The various parameters such as the effect of shaking time, initial Mn²⁺ concentration, temperature were controlled and optimized to removal of Mn²⁺ from synthetic wastewater. The kinetics and adsorption isotherms for Mn²⁺ removal from wastewater were studied in batch mode. At temperatures of 10 °C and 20 °C the adsorption equilibrium was reached after 24 h. Adsorption isotherms of Mn²⁺ are well fitted by Langmuir and Freundlich isotherm equation. The adsorption capacity of Mn²⁺ from synthetic wastewater of 80.607 mg/kg was obtained for (Mg-Al-Ni)-LDH. It is found that the adsorption kinetics is best described by the pseudo-second order model. These results prove that LDHs can be considered as a potential material for adsorption of Mn²⁺ from wastewater.

Phosphors based on magnesium titanate activated with Mn⁴⁺ ions are of great interest because, when excited with blue light, they display a strong red-emitting luminescence. They are characterized by a luminescence decay which is strongly temperature dependent in the range from 0 to 80 °C, making these materials very promising for temperature sensing in the biochemical field. In this work the optical and thermal properties of the luminescence of Mg₂TiO₄ are investigated for different Mn⁴⁺ doping concentrations. The potential of this material for temperature sensing is demonstrated by fabricating a fiber optic temperature microsensor and by comparing its performance against a standard resistance thermometer. The response of the fiber optic sensor is exceptionally fast, enabling monitoring of temperature fluctuation in subsecond time domain.

Solution combustion synthesis (SCS) is often utilized to prepare crystalline nanoparticles of transition metal oxides, in particular Mn oxides. The structure and composition of the final product depend on the conditions of the synthesis, in particular on the composition of metal precursors, its molar ratio to the fuel component, and the mode of heating. In the present work the study of chemical phenomena which may occur in the during SCS process has been studied for the conventional nitrate-glycine synthesis of Mn oxide, as well as for nitrate-citrate-glycine and nitrate-citrate-urea synthesis. In the case of nitrate-glycine synthesis, formation of a weak complex of Mn(II) and glycine provides the conditions of instantaneous SCS reaction upon heating, resulting in slight sintering of final oxide nanoparticles. However, partial hydrolysis of Mn precursor during slow solvent evaporation results in formation of mixture of oxides, namely MnO and Mn3O4. Formation of MnO is completely suppressed in the presence of ammonium citrate in the initial mixture, and pure Mn3O4 phase is obtained. SCS reaction in this case is slower, resulting in stronger sintering of the nanoparticles. The study of electrochemical properties of synthesized oxides demonstrated that the SCS with nitrate-citrate-urea mixture provides the highest charge capacitance in 1M NaOH: 130 F/g at 2 A/g. Impedance characterization of materials allowed to propose a tentative mechanism of degradation of electrode materials during the galvanostatic cycling.

Carbon dioxides capture chemical looping combustion (CLC) technology uses metal oxides as oxygen transporters (TO). (1) These oxygen transporters, OXMN009 and OXMN009P, are used in a cyclic process that prevents the formation of nitrogen oxides by keeping air and fuel separate. (2) Thermogravimetric balance (TGA) experiments were conducted to evaluate the kinetic behavior of these copper-modified oxygen transporters. (3) It was found that OXMN009P has improved reactivity and oxygen transfer properties due to copper impregnation. The kinetic parameters obtained in the TGA indicate that the reaction is non-thermal and requires less energy to initiate. (4) The results show that OXMN009P has reactivity comparable to other manganese-based materials reported in the literature and can be an effective option for carbon dioxide capture.

White-rot fungi (WRF) have specific enzymes to degrade lignocellulosic and phenolic compounds. Therefore, their direct application could be an alternative to biodegrade complex lignocellulosic biomass such as olive mill solid waste (OMSW). The aim of this study was to evaluate the capacity of A. discolor and S. hirsutum to grow in OMSW as the sole substrate under static conditions and evaluate the phenolic removal compounds and lignin degradation. The lignolytic enzyme activity was determined, as was the phenolic compound removal. At the same time, lignin degradation and structural changes were evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscope (SEM), respectively. Both strains were able to grow using OMSW as the sole substrate without adding other nutrients, oxygen and/or agitation. The higher ligninolytic enzyme activity was found at day 8, and the highest phenolic removal (more than 80% with both strains) was reached after 24 days of incubation. The CLSM analysis confirmed lignin degradation through the drop in lignin fluorescence from 3967 for untreated OMSW to 235 and 221 RFU after 24 days of treatment by A. discolor and S. hirsutum respectively. The results indicate that both WRF could be suitable candidates to design an in-situ pretreatment step of OMSW, as long as in future research the WRFs have the same performance in non-sterile conditions.

In order to discover how formed the multiple oxides observed in the final external scales after long exposure of a low–Mn high–Cr Cantor’s alloy to hot air, oxidation tests in furnace were performed for seven different durations. Metallographic characterization was carried out concerning the oxidation products obtained after each test duration. The different oxides did not appear one after the other, but simultaneously, at the early beginning of the exposure to hot air and after. They thickened all progressively and the chemical composition of each also evolved with time, more or less. Globally the innermost oxide is almost chromia much richer in Cr than in Mn while the outermost one contains Mn principally. The interrupted tests also allowed specifying the mass gain kinetic, which is parabolic, twice faster than a chromia–forming alloy. Despite the lowered content in Mn, manganese still plays an important role in the oxidation phenomenon, starting very early.

The transport of iron(III) from Fe(III)-Mn(II)-HCl mixed solutions through a flat-sheet supported liquid membrane is investigated, being the carrier phase of Cyanex 923 (commercially available phosphine oxide extractant) dissolved in Solvesso 100 (commercially available diluent), as a function of hydrodynamic conditions, concentration of manganese and HCl in the feed phase, and carrier concentration in the membrane phase. A transport model is derived that describes the transport mechanism, consisting of diffusion through a feed aqueous diffusion layer, a fast interfacial chemical reaction, and diffusion of the Fe(III)-Cyanex 923 complex across the membrane phase. The membrane diffusional resistance (Δm) and feed diffusional resistance (Δf) are calculated from the model, and their values are 145 s/cm and 361 s/cm, respectively. It is apparent that the transport of iron(III) is mainly controlled by diffusion through the aqueous feed boundary layer, being the thickness of this layer calculated as 2.9x10-3 cm. Since Mn(II) is not transported through the membrane phase, the present system allows to the purification of this manganese-bearing solutions.

In the outskirts of the Pinios dam reservoir (Ilia Regional Unit, Greece) a freshwater refinery serves the water supply needs of the surrounding Municipalities, in which high concentrations of Fe and Mn, before treatment, have been observed. The main purpose of this research is to investigate the mechanism of increased iron (Fe) and manganese (Mn) levels in the reservoir of the Pinios dam, which impacts its freshwater refinery's operation. A comprehensive hydrochemical and sedimentological analysis was conducted over a hydrological year, focusing on the spatial and temporal distribution of Fe and Mn in both water and sediment samples across the established research monitoring stations. Sediment samples from the reservoir's bottom revealed predominantly fine-grained material, rich in total organic carbon, with elevated Mn and Fe oxide levels. Significant seasonal variations in Fe and Mn levels were also discovered, with higher Mn levels observed in the anoxic bottom waters of the reservoir during the dry season, attributed to the reduced conditions favoring Mn oxide dissolution over Fe. Conversely, during the wet season, a homogenization of metal concentrations throughout the water column was observed due to increased oxygenation and freshwater inflow. These outcomes were confirmed by the hydrochemical analysis, indicating that the redox conditions, pH, temperature, as well as the presence of organic matter significantly influence the mobility and bioavailability of these metals in the reservoir. The findings of this study clarify that the high concentration of Fe and Mn can be linked to the mineral composition of the upstream Neogene and flysch formations in the study area. As these formations are affected by geological weathering, they tend to enrich the streams, through soil erosion and runoff processes, in metals like Fe and Mn, which are eventually transported into the dam reservoir. This study highlights the critical role of geological, sedimentological and hydrological factors in shaping the hydrochemistry of dam reservoirs, providing essential insights for water resource management and environmental conservation strategies.

The study reports the effect of some metal carbides (niobium carbide, vanadium carbide, titanium carbide, and manganese sulfide) on hydrogen embrittlement in the pipeline industry using plane wave’s density functional theory (DFT). Our results predicted that the interaction of hydrogen molecules with these metals carbide occurs in the long range with binding energy varying in the energy window [0.70eV to 0.043eV]. Also, our study shows the desorption of H2 molecules from these metal carbides in the chemisorptions. Since, hydrogen embrittlement, occurs in the atomic state of hydrogen, therefore our finding in the atomic interaction of hydrogen with NbC, VC, TiC, and MnS showed that the strength of the trapping of the hydrogen atom could be classified as: TiC+H>VC+H>NbC+H> MnS+H. In addition, our study reveals that the carbon site is the most favorable hydrogen trapping site than the metal one. Furthermore, our results demonstrate that increasing the layer can also be an efficient way to enhance the trapping capacity.

A conventionally cast CoNiFeMn0.5Cr1.5 alloy and two versions with 0.25C&3.7Ta or 0.25C&3.7Hf were tested in oxidation at 1000°C for 50h with thermogravimetric recording of the oxidation kinetic. In all cases the obtained mass gain curves are parabolic. Their parabolic constants are much lower than the Kp previously determined for the original alloys with an equimolar base (CoNiFeMnCr). However, the post–mortem exploitation of the oxidized samples revealed analogous oxidation features on surface and subsurface, with here too external oxide strata on surface with different Mn and Cr contents, and rather great Mn–depletion in addition to a moderate Cr–depletion, in subsurface. Globally, the oxidation behavior is significantly better than earlier observed for the equimolar version of these alloys.

The innate immune system is the first line of host defense sensing viral infection. Manganese (Mn) has recently been found to be involved in the activation of innate immune DNA sensing cGAS-STING pathway and subsequent anti-DNA virus function. However, whether Mn2+ mediates host defense against RNA viruses is still unclear. In the current study, we demonstrated that Mn2+ exhibited antiviral effects against various animal and human viruses including RNA viruses such as PRRSVs and the VSV as well as a DNA virus such as the HSV1 in a dose-dependent manner. Moreover, cGAS and STING were both investigated in the Mn2+ mediated antiviral roles using the knockout cells made by CRISPR-Cas9 approach. Unexpectedly, the results revealed that neither cGAS knockout nor STING knockout had any effect on Mn2+ mediated antiviral functions. Nevertheless, we verified that Mn2+ promoted the activation of cGAS-STING signaling pathway. These findings suggest that Mn2+ has broad spectrum antiviral activities in a cGAS-STING pathway independent manner. This study also provides significant insights into redundant mechanisms participating in the Mn2+ antiviral functions and also indicates new target for Mn2+ antiviral therapeutics.

This paper seeks to examine how the Mn-Co spinel interconnect coating microstructure can in-fluence the Cr contamination in an oxygen electrode of intermediate temperature Solid Oxide Cells at the operating temperature of 750 °C. A Mn-Co spinel coating is processed on Crofer 22 APU substrates by electrophoretic deposition and subsequently sintered following both the one-step and two-step sintering, in order to obtain significantly different densification levels. The electrochemical characterization is performed on anode supported cells with a LSCF cathode. The cells were aged prior to the electrochemical characterization in contact with the spinel coated Crofer 22 APU at 750 °C for 250 hours. Current-voltage and impedance spectra of the cells were measured after the exposure with the interconnect. Post-mortem analysis of the interconnect and the cell was carried out in order to assess the Cr retention capability of coatings with different microstructures.

Single-Molecule Magnets (SMMs) have attracted much interest because of their spin properties and potential technological applications. Besides, a great effort has been devoted to their functionalization, which is made with functional groups convenient to connect suitable SMMs to junction devices or to perform their grafting on surfaces of different substrates. We have synthesized and characterized two lipoic acid-functionalized and oxime-based MnIII compounds, of formula [Mn6(μ3-O)2(H2N-sao)6(lip)2(MeOH)6][Mn6(μ3-O)2(H2N-sao)6(cnph)2(MeOH)6]}·10MeOH (1) and [Mn6(μ3-O)2(H2N-sao)6(lip)2(EtOH)6]·EtOH·2H2O (2) [H2N-saoH2 = salicylamidoxime, lip = lipoate anion, cnph = 2-cyanophenolate anion]. 1 crystallizes in the triclinic system with space group Pī and 2 crystallizes in the monoclinic system with space group C2/c. In their crystal packing, adjacent Mn6 complexes are connected through non-coordinating solvent molecules, which are H-bonded to N atoms of –NH2 groups of salicylamidoxime ligand. In addition, Hirshfeld surfaces of 1 and 2 were calculated to study the variety of intermolecular interactions and different level of importance that take place in their crystal lattice, this type of computed study being the first time performed on Mn6 molecules. The study of the magnetic properties of 1 and 2 through dc magnetic susceptibility measurements reveals the coexistence of ferro- and antiferromagnetic exchange couplings between the Mn(III) metal ions in both compounds, the latter being the predominant magnetic interaction. A ground state spin value of S = 4 was obtained through isotropic simulations of the experimental magnetic susceptibility data for both 1 and 2. Ac magnetic susceptibility measurements show the occurrence of slow relaxation of the magnetization in 1 and 2, which indicate that SMM behavior take place in both compounds.

Mn-promoted bulk iron catalysts with high specific surface area (82-211 m2.g-1) were synthesized by coprecipitation followed by drying under supercritical conditions. The catalysts were tested in the CO2 hydrogenation reaction. The Mn-promoted iron catalysts showed better textural properties than the bare Fe2O3 catalyst, allowing better dispersion of the active phase, easier reduction of iron oxide, better carburization of iron oxides and higher catalytic activity than the bare Fe2O3 catalyst. The best activity results were obtained by catalyst promotion with a very low amount of Mn (Mn/Fe ratio of 0.05). Upon steady-state conditions (T=340 ºC, total pressure of 20 bar and H2/CO2=3), this catalyst showed high CO2 conversion (44.2%) and selectivity to C2-C4 hydrocarbons (68%, olefin to paraffin ratio of 0.54), while the selectivity to C5+ hydrocarbons, CH4 and CO was about 3.2, 38.5 and 5%, respectively. A close correlation was found between catalyst textural properties and CO2 conversion. The most active MnFe-0.05 catalyst shows high stability during 72 h of reaction related to low amount of soft coke formation and catalyst activation through the formation of χ-Fe5C2 phase during the on-stream reaction.

In this work, we report manganese phthalocyanine (MnPc) films obtained by ultrasonic spray-pyrolysis technique at 40°C deposited on glass substrate subjected to thermal annealing at 100 °C and 120°C. The MnPc films were characterized by UV/Vis spectroscopy, Raman spectroscopy, X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The absorption spectra of the MnPc films were studied in a wavelength range from 200 to 850 nm, where the characteristic bands of a metallic phthalocyanine known as B and Q bands were observed in this range of the spectrum. The optical energy band (Eg) was calculated by the Tauc equation. It was found that for these MnPc films, the Eg has the values of 4.41, 4.46 and 3.58 eV corresponding to as deposited, annealing 100°C and 120°C, respectively. The Raman spectra of the films showed their characteristic vibrational modes of the MnPc films. In X-ray diffractograms of these films, the characteristic diffraction peaks of a metallic phthalocyanine are observed, presenting a monoclinic phase. SEM images of these films were studied in cross section obtaining thicknesses of 2, 1.2 and 0.3 μm to as deposited, annealing 100°C and 120°C, successively. Also, in the SEM images of these films, both the average particle sizes ranging from 4 to 0.041 µm and the average diameter from 4.8 to 0.091 μm were obtained. The results agree with those reported in the literature for MnPc films deposited with other techniques.

Manganese dioxide (MnO2) has drawn attention as a sensitizer to be incorporated in graphene-based chemoresistive sensors thanks to its promising properties. In this regard, a rGO@MnO2 sensing material was prepared and deposited on two different substrates (Silicon and Kapton). These sensors were exposed to different dilutions of NO2 under dry and humid conditions at room temperature. Other gases or vapours such as NH3, CO, ethanol and H2 were also tested. FESEM, HRTEM, RAMAN and XRD were used to characterize the prepared sensors. The experimental results showed that the incorporation of MnO2 in the rGO material enhanced its response towards NO2. Moreover, this material showed also very good responses toward NH3 both under dry and humid conditions and showed no cross-responsiveness towards other toxic gases.

A novel composite consisting of fluorine-doped carbon and graphene double-coated LiMn0.6Fe0.4PO4 (LMFP) nanorods, synthesized via a facile low temperature solvothermal method that employs a hybrid glucose and polyvinylidene fluoride as carbon and fluorine sources. As revealed by physicochemical characterization, F-doped carbon coating and graphene form a ‘point-to-surface’ conductive network, facilitating rapid electron transport and mitigating electrochemical polarization. Furthermore, the uniform thickness of the F-doped carbon coating alters the growth of nanoparticles and prevents direct contact between the material and the electrolyte, thereby enhancing structural stability. Strong electronegative F− is beneficial to inhibit the structural changes of LMFP caused by Li-insertion/extraction during charge/discharge, which effectively reduces the Jahn-Teller effect, and inhibits Mn dissolution. The distinctive architecture of LMFP/C-F/G cathode material exhibits excellent electrochemical properties, exhibiting an initial discharge capacity of 163.1 mAh g−1 at 0.1 C and a constant Coulombic efficiency of 99.7% over 100 cycles. Notably, LMFP/C-F/G cathode material achieves an impressive energy density of 607.6 Wh kg−1 , surpassing that of commercial counterparts. Moreover, it delivers a reversible capacity of 90.3 mAh g−1 at a high current rate of 5 C. The high-capacity capability and energy density of the prepared materials give them great potential for use in next-generation lithium-ion batteries.

When wastewater containing methylene blue, a cationic dye is improperly treated or immediately dumped into the environment, it can degrade the quality of water bodies and contaminate the ecological environment. The removal of methylene blue from the aqueous solution is critical and urgent. The present work focuses on the use of maize stalk agricultural waste to prepare an adsorbent for the removal of cationic dye (methylene blue) from an aqueous solution. The prepared maize stalk biochar (MSB) was modified with MnO2 and the modified maize stalk biochar was characterized using Fourier transform infrared (FTIR) spectroscopy. Taguchi technique was employed to determine the optimum conditions for the removal of methylene blue (MB) dye from aqueous solution by MMSB. The factors were adsorbent dose (0.5, 1.0 and 1.5 g/100 mL), initial dye concentration (100, 200 and 300 mg/L), contact time (30, 60, 90 minutes) and pH (4, 6 and 8). Among the investigated process factors, adsorption efficiency was influenced by adsorbent dose and initial MB dye concentration. The optimum parameters were 1 g/100 mL adsorbent dose, 100 mg/L initial dye concentration, 60 minutes contact time and a pH of 8.0. This yielded a removal efficiency of 87.49% with adsorption capacity of 206.53 mg/g. The adsorption kinetics agreed with the pseudo-second-order (R2 of 0.999968) model and fitted a Langmuir isotherm (R2 of 0.9795) representing homogeneous monolayer chemisorption.

Nitric acid is a key component in the production of nitrate fertilisers and is industrially produced using the Ostwald process. The Ostwald process can be further intensified by oxidising nitric oxide to nitrogen dioxide using heterogeneous catalysts. We have explored various monometallic and bimetallic catalysts for NO to NO2 oxidation and found ruthenium supported on ceria, containing 10 wt.% manganese to be a promising catalyst for oxidising NO to NO2 at low temperatures at industrially relevant conditions. For a feed comprising 10% NO, 6% O2, 15% H2O and rest Ar, and 8% NO, 2% NO2 5% O2, 15% H2O and rest Ar, the ruthenium-manganese catalysts attained NO-NO2 equilibrium below 400∘C. For the 5wt.% ruthenium and 10 wt.% manganese on ceria catalyst, an apparent activation energy of 39.4 kJ/mol and 85.4 kJ/mol were observed in the absence and presence of NO2, respectively. These findings demonstrate the potential of supported bimetallic ruthenium-manganese catalysts for efficient oxidation of NO to NO2 at low temperatures which can lead to significant process intensification of nitric acid plants.

Aquatic animals have unique physiological mechanisms to absorb and retain minerals from their diets and water. Research and development in the area of mineral nutrition of farmed fish and crustaceans have been relatively slow and major gaps exist in the knowledge of trace element requirements, physiological functions and bioavailability from feed ingredients. Quantitative dietary requirements have been reported for three macroelements (calcium, phosphorus and magnesium) and six trace minerals (zinc, iron, copper, manganese, iodine and selenium) for selected fish species. Mineral deficiency signs in fish include reduced bone mineralization, anorexia, lens cataracts (zinc), skeletal deformities (phosphorus, magnesium, zinc), fin erosion (copper, zinc), nephrocalcinosis (magnesium deficiency, selenium toxicity), thyroid hyperplasia (iodine), muscular dystrophy (selenium) and hypochromic microcytic anaemia (iron). An excessive intake of minerals from either diet or gill uptake causes toxicity and therefore a fine balance between mineral deficiency and toxicity is vital for aquatic organisms to maintain their homeostasis either through increased absorption or excretion. Release of minerals from uneaten or undigested feed and from urinary excretion can cause eutrophication of natural waters, which requires additional consideration in feed formulation. The current knowledge in mineral nutrition of fish is briefly reviewed.

Cardiovascular diseases (CVDs) constitute the first cause of death among the population of developing and developed countries. Atherosclerosis, which is a disorder with multifactorial etiopathogenesis, underlies most CVDs. The available literature includes ample research studies on the influence of classic cardiovascular (CV) risk factors. However, environmental exposure to heavy metals, among other substances, is still an unappreciated risk factor of CVDs. This study aimed to assess the concentration of some heavy metals (copper (Cu), zinc (Zn), manganese (Mn), cobalt (Co), and iron (Fe)) in the blood serum of postmyocardial infarction (post-MI) patients and patients free from myocardial infarction (MI) as well as estimate the relationship between the occurrence of MI and increased concentration of heavy metals. The concentration of heavy metals (Cu, Zn, Mn, Co, and Fe) was assessed using the inductively coupled plasma mass spectrometry technique in a group of 146 respondents divided into two groups: post-MI group (study group (SG), n = 74) and group without cardiovascular event (CVE) having a low CV risk (control group (CG), n = 72). The concentration of the analyzed heavy metals was higher in SG. All the heavy metals showed a significant diagnostic value (p < 0.001). The highest value of area under the curve (AUC) was observed for manganese (Mn) (0.955; 95% confidence interval (CI) = 0.922–0.988), while the lowest value was found for zinc (Zn) (0.691; 95% CI = 0.599–0.782). In one-dimensional models, high concentrations of each of the analyzed heavy metals significantly increased the chances of having MI from 7-fold (Cu) to 128-fold (Mn). All the models containing a particular metal showed a significant and high discrimination value for MI occurrence (AUC 0.72–0.92). Higher concentrations of Cu, Zn, Mn, Co, and Fe were found to considerably increase the chances of having MI. Considering the increasingly higher environmental exposure to heavy metals in recent times, their concentrations can be distinguished as a potential risk factor of CVDs.

Microbial populations involved in forming the distinctive precipitates of the S, Fe, Mn, and Ca cycles in the San Diego River watershed reflect an interplay between mineralogy of the rocks in the watershed, sparse rainfall, ground- and surface-water anoxia, and runoff of high sulfate, treated imported water. In the less developed headwaters, Temescal Creek tributary emerges from pyrite-bearing metamorphic rocks, and thus exhibits both an oxidized Fe and reduced S cycle. In the middle reaches, the river moves through developed land where treated, imported high sulfate Colorado River water enters from urban runoff. Mast Park surrounded by caliche-bearing sedimentary rocks is a site where marl is precipitating. Cobbles in riffles in the river are coated black with Mn oxide. When the river encounters deep-seated volcanic bedrock, it wells up to precipitate both Fe and Mn oxides at Old Mission Dam. Then, directly flowing through caliche-laced sedimentary rocks, Birchcreek tributary precipitates tufa. Further downstream, at a site that periodically receives full sunlight, a sulfuretum sets up during the summer when the river is deoxygenated. Such a rich geochemistry results in activity of iron and manganese oxidizing bacteria, sulfur oxidizers and reducers, and cyanobacteria precipitating calcareous marl and tufa.

Li-rich manganese-based cathode materials (LRMs) are considered one of the most promising cathode materials for the next generation lithium-ion batteries (LIBs) because of their high energy density. However, there are problems such as capacity decay, poor rate performance, and continuous voltage drop, which seriously limit their large-scale commercial applications. In this work, Li1.2Mn0.54Co0.13Ni0.13O2 coated with Li2MoO4 with unique spinel structure was prepared by wet chemistry method and the subsequent calcination process. The Li2MoO4 coating layer with spinel structure can provide a 3D Li+ transport channel, which is beneficial for improving rate performance, while protecting LRMs from electrolyte corrosion, suppressing interface side reactions, and improving cycling stability. The capacity retention rate of LRMs coated with 3wt% Li2MoO4 increased from 69.25% to 81.85% after 100 cycles at 1C, and the voltage attenuation decreased from 7.06 to 4.98 mV per cycle. The lower Rct also exhibits improved magnification performance. The results indicate that the Li2MoO4 coating effectively improves the cyclic stability and electrochemical performance of LRMs.

Sensors became integrated through the control condition arrangement, either for visual, mechanical, biological, or chemical applications. New stuff is designed for detection, as Diluted Magnetic Semiconductors (DMS), and are considered attractive candidates that consist of a traditional 111- V, II-VI, or group IV semiconductor. Manganese Mn-doped GaN (Mn.Gac.N) epitaxial velum has a unique magnetic, visual and chemical properties in order to control system intelligent for detector design. The subject area of the magnetic properties of MnxGal-xN is on a large scale available, there are only a few studies on the visual properties and electrochemical properties of MnxGal-xN epitaxial velums. Where MnGaN velums were used in spintronic and opto-electronic applications according to their magnetic characterization and constructed MnGaN electrode are drop fabric potential for potentiometric sensor applications since they have good performance as ion-selective electrodes. The electrical and magnetic properties that allow the control of electron spin as well as complaint period, makes the materials ideal for spintronic applications. Designing such spintronic and optoelectronic devices based on MnxGal-xN requires a broader agreement of physical, visual, electrical and chemical properties epitaxial velums that are still seldom in the literature. This bailiwick displays the potential use of MnGaN semiconductor as an all solid-state potentiometric sensor for measuring anions in solutions in the control engineering field.

Three types of the composites were tested for electromagnetic interference (EMI) absorption shielding effectiveness, curing process and physical-mechanical properties. In the first type of composites, manganese-zinc ferrite, nickel-zinc ferrite, and both fillers in their mutual combinations were incorporated into acrylonitrile-butadiene rubber. The overall content of the filler, or fillers combinations was kept on 200 phr. Then, carbon black, or carbon fibres, respectively were incorporated into each rubber formulation in constant loading - 25 phr, while the content of magnetic fillers was unchanged - 200 phr. The work was focused on the understanding of correlation among electromagnetic shielding parameters and electrical conductivity of composites in relation to their EMI absorption shielding effectiveness. The absorption shielding ability of materials was evaluated within the frequency range from 1 MHz to 6 GHz. The study revealed good correlation among permittivity, conductivity, and EMI absorption effectiveness. Although, the absorption shielding efficiency of composites filled only with ferrites seems to be the highest, the absorption maxima of those composites were reached over 6 GHz. The application of carbon based fillers resulted in higher electrical conductivity and higher permittivity of composites, which was reflected in their lower absorption shielding performance. Though, the composites with filled with ferrites and carbon based fillers absorbed electromagnetic radiation within the desired frequency range. The presence of carbon based fillers caused the improvement in tensile behavior of composites. The study also demonstrated that the higher was the ratio of nickel-zinc ferrite in magnetic fillers combinations, the higher was the absorption shielding performance.

The research presented in the article is devoted to the study of the influence of phase compounds on the friability of the Fe-Si-Mn-Al complex alloy. The urgency of the problem lies in the development of technology for producing a non-scatterable alloy from manganese-containing ores and high-ash coals. The main goal of the work is to determine the range of alloy compositions and the resulting phases that affect the dispersibility of the alloy, which is critically important for its industrial implementation. Research methods include thermodynamic diagram analysis (TDA) using data on the standard enthalpy of formation of intermetallic compounds, as well as experimental tests in an ore-thermal electric furnace with a capacity of 200 kV*A. The results show that Fe-Si-Mn-Al complex alloys form a variety of silicide and aluminide phases, including intermetallic compounds and ternary systems, which is critical for understanding and controlling their physicochemical properties. When smelting a complex alloy, the content of leboite (Fe3Si7) in the Fe-Si-Mn-Al system plays a significant role. The development of smelting technology will be aimed at avoiding the FeSi2-Fe3Si7-F2(FeAl3Si2)-Mn11Si19 tetrahedron area. This approach to controlling the composition of a complex alloy is critical to ensuring its consistent friability properties in industrial applications. Thus, this work represents an important step in understanding the physical properties and stability of Fe-Si-Mn-Al complex alloys, which have potential for widespread use in metallurgical and other industrial applications.

Huntington’s disease (HD) is a rare but progressive and devastating neurodegenerative disease characterized by involuntary movements, cognitive decline, executive dysfunction, and neuropsychiatric conditions such as anxiety and depression. It follows an autosomal dominant inheritance pattern. Thus, a child who has a parent with the mutated huntingtin (mHTT) gene has a 50% chance of developing the disease. Since HTT protein is involved in many critical cellular processes including neurogenesis, brain development, energy metabolism, transcriptional regulation, synaptic activity, vesicle trafficking, cell signaling, and autophagy, its aberrant aggregates lead to disruption of numerous cellular pathways and neurodegeneration. Essential heavy metals are vital at low concentrations, however, at higher concentrations, can exacerbate HD by disrupting the glial-neuronal communication, and/or causing dysbiosis (disturbance in the gut microbiota, GM), both of which can lead to neuroinflammation and further neurodegeneration. Here, we discuss in detail the interactions of iron, manganese and copper with glial-neuron communication and GM and indicate how this knowledge may pave the way for development of a new generation of disease-modifying therapies in HD.

There is little doubt that the efficacy of MnDPDP and its therapeutic improved counterpart Ca4Mn(DPDP)5 mainly depends on their MnSOD-mimetic activity when it comes to their potential use as rescue medicines, during e.g., acute myocardial infarction. However, pharmacokinetic considerations suggest that the efficacy of MnDPDP on Pt2+-associated neurotoxicity depends on another action of this drug. Electron Paramagnetic Resonance (EPR) studies have demonstrated that Pt2+ outcompetes Mn2+ and endogenous Zn2+ from binding to fodipir (DPDP), and hence suggest that the previously reported CIPN protective efficacy of MnDPDP is a result of chelation and elimination of Pt2+ by DPDP, which in turn suggests that Mn2+ is unnecessary for efficacy when it comes to oxaliplatin-associated CIPN.

Manganosalen complexes are coordination compounds that possess a chelating salen-type ligand, a class of bis-Schiff bases obtained by condensation of salicylaldehyde and a diamine. They may act as catalytic antioxidants mimicking both the structure and the reactivity of the native antioxidant enzymes active site. Thus, manganosalen complexes have shown to exhibit superoxide dismutase, catalase, and glutathione peroxidase activities, and they could potentially facilitate the scavenging of excess ROS, thereby restoring the redox balance in the damaged cells and organs. Initial catalytic studies compared the potency of these compounds as antioxidants in terms of rate constants of the chemical reactivity against ROS, giving catalytic values approaching and even exceeding that of the native antioxidative enzymes. Although most of these catalytic studies lack of biological relevance, subsequent in vitro studies have confirmed the efficiency of many manganosalen complexes in oxidative stress models. These synthetic catalytic scavengers, cheaper than natural antioxidants, have accordingly attracted intensive attention for the therapy of ROS-mediated injuries. The aim of this review is to focus on in vivo studies performed on manganosalen complexes and their activity on the treatment of several pathological disorders associated with oxidative damage. This disorders, ranging from the prevention of fetal malformations to the extension of lifespan, include neurodegenerative, inflammatory and cardiovascular diseases, tissue injury, and other damages related to liver, kidney or lungs.

Two experiments were conducted to develop a Nano green manganese and assess its effect on grapevines. The first experiment was microbiological, where several incorporation strategies were utilized to enrich the yeast with manganese, as follows: (1) adding manganese to the liquid medium (growth phase), (2) adding after 24 h of incubation (non-growth phase). As the results, growth phase reduced the possibility of medium contamination. Manganese concentration in the yeast cells was increased as that of manganese sulphate in the medium. Manganese incorporation in yeast cells was 99.93% higher than that of the medium at 0.0195 g/l of manganese. Although the concentration of manganese in the medium raised the OD of yeast cell biomass, manganese sulphate had no passive influence on it. The second experiment was horticultural, done on Flame Seedless grapevines, since both active fresh and frozen yeast enriched with manganese resulted from the first experiment were sprayed twice a year at 10 or 20 cm3/l comparing with manganese sulphate, and manganese chelate. The results demonstrated that yeast extracts in both forms increased the yield and improved fruit properties. The most effective treatment on vegetative growth, yield and fruit properties was the frozen yeast enriched with manganese at 20 cm3/l.

In the past decade, under the background of the carbon peaking and carbon neutrality era, the rapid development of new energy vehicles has put forward higher requirements for the performance of strike forces such as battery cycle life, energy density and cost. Lithium-ion batteries have gradually become the mainstream of electric vehicle power batteries due to their excellent energy density, rate performance and cycle life. At present, the most widely used cathode materials for power batteries are lithium iron phosphate (LFP) and ternary nickel-cobalt-manganese (NCM). However, these materials exhibit the bottlenecks that limit the improvement and promotion of power battery performance. In this review, the performance characteristics, cycle life attenuation mechanism (including structural damage, gas generation and active lithium loss, etc.) and improvement methods (including surface coating and element-doping modification) of LFP and NCM batteries are reviewed. Finally, the development prospects of this field are proposed.

The achievement of size uniformity and monodispersity in perovskite quantum dots (QDs) requires the implementation of precise temperature control and the establishment of optimal reaction conditions. Nevertheless, the accurate control of a range of reaction variables represents a considerable challenge. This study addresses the aforementioned challenge by employing manganese (Mn) doping to achieve size uniformity in CsPbBr₃ perovskite QDs without the necessity for precise control of the reaction conditions. By optimizing the Mn:Pb ratio, it is possible to successfully dope CsPbBr₃ QDs with appropriate concentrations of Mn²⁺ and achieve a uniform size distribution. The spectroscopic measurements on single QDs indicate that the appropriate Mn²⁺ concentrations can result in a narrower spectral linewidth, a longer photoluminescence (PL) lifetime, and a reduced biexciton Auger recombination rate, thus positively affecting the PL properties. This study not only simplifies the size control of perovskite QDs, but also demonstrates the potential of Mn-doped CsPbBr₃ QDs for narrow linewidth light-emitting diode applications.

Hydroxyapatite (HAP) is the main mineral component of bones and teeth. It is widely used in medicine as a bone filler and coating for implants to promote new bone growth. Ion substitutions into the HAP structure highly affect its properties. One of the important substituents is manganese. This paper presents the new results obtained by high-precision density functional theory calculations using hybrid functionals, for studies of the Mn/Ca substitutions in HAP in a wide manganese concentration range within 2x2x2 supercell model. The experimental data on the mechanochemical synthesis of HAP-Mn samples with different Mn concentrations are also presented. The comparison between experiment and theory showed good agreement: the HAP-Mg unit cell parameters and volume decrease with increasing degree of Mn/Ca substitution. It is shown that electronic energy levels appear inside the band gap Eg of HAP, which depend on the concentration of Mn and change the photo-excitation energy of HAP, making its effective value Eg* less than the band gap Eg, and generally changing the photoelectronic properties of HAP. It was established that the energies of formation of the substitutions Mn/Ca depend on the position of the Ca atom (Ca1 or Ca2) and on the concentration of manganese. It has been shown that the replacement of calcium cations with manganese occurs predominantly at the Ca2 position.

In order to obtain the good match between yield strength and low-temperature toughness, the short-time partial austenitization (SPA) process was employed for V-microalloying 0.22C-5.24Mn steel. The initial microstructure after intercritical tempering was dual-phase ferrite and reversed austenite (RA), while the final microstructure was consisted of ferrite, RA and secondary martensite (SM) after subjected to SPA process. (V, Mo)C with disc-like morphology mainly precipitated during intercritial tempering, and the aspect ratio of particle decreased, leading to the appearance of near-spherical morphology. After subjected to SPA process, the resultant multiphase hierarchical microstructure (three layers: out layer of ferrite, interlayer of SM and inner layer RA) enabled high yield strength of 1097 MPa, total elongation of 14%, and impressive impact energy of 33.3 J at -20 °C. The strengthening contribution of (V, Mo)C precipitation was estimated about 108 MPa.

The wealth of data obtained during the past 20 years using Laser-Induced Breakdown Spectroscopy (LIBS) indicates that the technique is very promising to detect small chemical contents of alloying elements. The potential of LIBS was looked more seriously during the past two decades or so as more data were obtained on Aluminum and steel to study the phenomena in the condition of local thermodynamic equilibrium and time-delay between a Q-switch laser and an intensified CCD camera. Since the past decade, some data on compounds were also shown to be useful in determining small concentrations of harmful elements. This manuscript is intended to show that the technique of LIBS performance is very promising in fields such as micro-machining, in alloying element analysis, surface cleaning and environmental applications even with lightweight spectrometers having a relatively low resolution, which can potentially be air-borne.