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A comprehensive study on the photo-excited relaxation dynamics in semiconducting perovskite quantum dots (PQDs) is pivotal in realizing their extensive potential for optoelectronics applications. Among different competing photoinduced relaxation kinetics, energy transfer and charge transfer (CT) in PQDs need special attention, as they often influence the device efficacy, particularly with the donor–acceptor hybrid architecture. In this work, we explore a detailed investigation into photoinduced CT dynamics in mixed halide undoped CsPb(Br/Cl)3 and Mn2+ doped CsPb(Br/Cl)3 PQDs with a quinone molecule, p-benzoquinone (BQ). The energy level alignment of undoped PQDs with BQ allows an efficient CT, whereas Mn2+ doping reduces the CT efficiency, experiencing a competition between energy transfer from host to dopant and CT to BQ. The conductive atomic force microscopy measurements unveil a direct correlation with the spectroscopic studies by showing a significant improvement in the conductance of undoped PQDs in the presence of BQ, while an inappreciable change is observed for doped PQDs. A much-reduced transition voltage and barrier height in the presence of BQ further validate faster CT for undoped PQD than the doped one. Furthermore, Mn2+ doping in PQDs is observed to enhance their stability, showing better air and thermal stability compared to their undoped counterparts. These results reveal that doping strategy can regulate the CT dynamics in these PQDs and increase their stability, which will be beneficial for the development of desired optoelectronic devices with long-term stability. [ABSTRACT FROM AUTHOR]

The structure and mechanism of the water-oxidation chemistry that occurs in photosystem II have been subjects of great interest. The advent of X-ray free electron lasers allowed the determination of structures of the stable intermediate states and of steps in the transitions between these intermediate states, bringing a new perspective to this field. The room-temperature structures collected as the photosynthetic water oxidation reaction proceeds in real time have provided important novel insights into the structural changes and the mechanism of the water oxidation reaction. The time-resolved measurements have also given us a view of how this reaction-which involves multielectron, multiproton processes-is facilitated by the interaction of the ligands and the protein residues in the oxygen-evolving complex. These structures have also provided a picture of the dynamics occurring in the channels within photosystem II that are involved in the transport of the substrate water to the catalytic center and protons to the bulk.

The effects of isothermal annealing on the self-assembled nanostructures of spinel manganese oxide ZnMnGaO4 were investigated using transmission electron microscopy and x-ray diffraction. The checkerboard nanostructures and zigzag nanostructures (named "Sierra" nanostructures) coexisted owing to the chemical phase separation of Mn3+ and Ga3+ ions by isothermal annealing at 575 °C. It was observed that the checkerboard nanostructures were dominant in short-time annealing and that the volume fraction of the Sierra nanostructures became more prominent as the annealing period increase. The interdiffusion of Mn3+ and Ga3+ is indicated to play an important role in gaining the total energy of the system by the reduction in the local strain caused by the formation of nanostructures. These results provide further insights into the fabrication of distinct types of nanostructures in complex transition-metal compounds. [ABSTRACT FROM AUTHOR]

The effects of isothermal annealing on the self-assembled nanostructures of spinel manganese oxide ZnMnGaO4 were investigated using transmission electron microscopy and x-ray diffraction. The checkerboard nanostructures and zigzag nanostructures (named "Sierra" nanostructures) coexisted owing to the chemical phase separation of Mn3+ and Ga3+ ions by isothermal annealing at 575 °C. It was observed that the checkerboard nanostructures were dominant in short-time annealing and that the volume fraction of the Sierra nanostructures became more prominent as the annealing period increase. The interdiffusion of Mn3+ and Ga3+ is indicated to play an important role in gaining the total energy of the system by the reduction in the local strain caused by the formation of nanostructures. These results provide further insights into the fabrication of distinct types of nanostructures in complex transition-metal compounds. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the spin transport properties of binuclear manganese phthalocyanine (M n 2 P c 2) spintronic devices sandwiched between two nickel electrodes using the non-equilibrium Green's function method in combination with density functional theory. Based on the calculation results, the M n 2 P c 2 device exhibited excellent spin-filtering capabilities, demonstrating an exceptionally high spin filter efficiency (SFE). Irrespective of the parallel or antiparallel orientation of magnetization in the electrodes, we observed that when both manganese atoms were in a spin-up state, the SFE of spin-resolved currents under finite bias and the thermoelectric currents induced by temperature gradients at fixed temperatures were both close to 100%. The large spin Seebeck polarization of the M n 2 P c 2 device was also obtained at low reference temperatures. This study explores the potential for developing multifunctional spintronic single-molecule devices using Ni − M n 2 P c 2. [ABSTRACT FROM AUTHOR]

Using high-frequency electron paramagnetic resonance (EPR), we have observed the ferromagnetic coupling of manganese Mn2+ pairs in a layered van der Waals GaS semiconductor. The EPR spectra of Mn2+ pairs (Mn24+) [replacing covalently bonded Ga24+ pairs oriented along the chain axis (c axis) of two gallium ions and being situated in the center of the layer] were recorded at 94 and 130 GHz. The fine structure parameters for the lower multiplets with spin S = 5 and S = 4 were determined equal to D = −0.040 cm−1 and D ≅ −0.035 cm−1, respectively. Based on the observation of additional EPR lines in the region of intersection of the levels in the magnetic field of the multiplet with S = 5 and S = 4, the energy of the isotropic exchange interaction J was estimated to be ∼−0.5 cm−1. For all transitions, a well-resolved hyperfine structure was observed, due to the interaction with two equivalent 55Mn nuclei, leading to the appearance of 11 lines with a hyperfine interaction constant A = 30(1) × 10−4 cm−1, which is approximately half the hyperfine interaction constant for single Mn2+ ions. In addition, a signal from single manganese ions Mn2+ with spin S = 5/2 and a hyperfine interaction constant A = 60(1) × 10−4 cm−1 was observed, which are characterized by extremely large fine structure splitting of D = −0.15 cm−1. Simultaneously with EPR studies, the crystals were monitored by photoluminescence and micro-Raman scattering measurements using a microscope with confocal optics. [ABSTRACT FROM AUTHOR]

Higher manganese silicides have evolved as an efficient thermoelectric material because of their exceptional thermoelectric performance at intermediate temperatures. In this work, we report the ultralow-thermal conductivity with improved thermoelectric properties of Mn 1-x Cr x Si 1.8 (x = 0, 0.025, 0.05 and 0.1) prepared by induction melting followed by ball milling and uni-axial induction hot-pressing. Bragg diffraction patterns confirmed that the as-synthesized compound belongs to the Mn 15 Si 26 phase along with the solid solubility of Cr in the HMS lattice. In addition, the backscattered electron micrographs revealed the precipitation of excess Si in the HMS matrix, originating from Si-rich stoichiometry. Furthermore, an elevation in electrical conductivity with increasing Cr content has been observed because of its acceptor dopant behaviour at the Mn site. On the contrary, the Seebeck coefficient decreased upon an increase in Cr content, and bulk MnSi 1.8 has shown the highest Seebeck coefficient of 220 μV/K at 773 K. Impressively, nanostructuring along with the generated point defects as a result of Cr dopant facilitates an intensified phonon scattering at the nanostructured grain boundaries that results in a very low κ total of 0.99 W/mK at 773 K for ball-milled Mn 0.9 Cr 0.1 Si 1.8 , leading to an elevated zT of 0.46 at 773 K. [ABSTRACT FROM AUTHOR]

The Mn X Tm 1‒X Se (0 ≤ Х ≤ 0.2) solid solutions have been first synthesized and their structural, magnetic, and transport properties have been studied in the temperature range of 80–1000 K and magnetic fields of up to 12 kOe. The surface morphology of the samples has been examined and the chemical analysis has been carried out. It is shown that the valence change with the increasing substitution concentration is accompanied by a change in the lattice parameter and a decrease in the magnetic moment of the samples. The Kondo temperatures caused by the manganese and thulium subsystem have been found in the low- and room-temperature regions. The temperature of localization of small-radius polarons has been determined. A drastic decrease in the relaxation time in the range of the manganese ion percolation through the lattice in the Mn X Tm 1‒X Se system has been established. The change of the current carrier type upon variation in the temperature and substitution concentration was determined from the Seebeck coefficient. A high-temperature extremum of thermopower was revealed, which is explained within the framework of the Anderson model. [ABSTRACT FROM AUTHOR]

The halogen-free synthesis of oligosilazanes has been observed upon dehydrocoupling silanes with ammonia at 25 °C using [(2,6-iPr2PhBDI)Mn(µ-H)]2. Extending this methodology to polymethyl-hydrosiloxanes afforded thermally robust polysiloxazane solids, and the dehydrocoupling of 1,3,5,7-tetra-methylcyclotetrasiloxane with ammonia afforded a polysiloxazane having a weight-average molecular weight of 4300 g mol-1. A representative oligosilazane has been applied to a copper surface and found to afford a 20 μm thick coating that resists corrosion after 24 h under water. Addition of ammonia to [(2,6-iPr2PhBDI)Mn(µ-H)]2 allowed for characterization of the catalyst resting state, [(2,6-iPr2PhBDI)Mn(µ-NH2)]2, which has been found to mediate Si-N dehydrocoupling. [ABSTRACT FROM AUTHOR]

Introduction Military members and first responders may, at moment's notice, be asked to assist in incidents that may result in radiation exposure such as Operation Tomadachi in which the U.S. Navy provided significant relief for the Fukushima Daiichi Nuclear Reactor accident in Japan after an earthquake and tsunami in 2011. We are also currently facing potential threats from nuclear power plants in the Ukraine should a power disruption to a nuclear plant interfere with cooling or other safety measures. Exposure to high doses of radiation results in acute radiation syndrome (ARS) characterized by symptoms arising from hematopoietic, gastrointestinal, and neurovascular injuries. Although there are mitigators FDA approved to treat ARS, there are currently no FDA-approved prophylactic medical interventions to help protect persons who may need to respond to radiation emergencies. There is strong evidence that manganese (Mn) has radiation protective efficacy as a promising prophylactic countermeasure. Materials and Methods All animal procedures were approved by the Institutional Animal Care and Use Committee. Male and female B6D2F1J mice, 10 to 11 weeks old, were used for neurotoxicity studies and temporal effects of Mn. Four groups were evaluated: (1) vehicle injection, (2) dose of 4.5 mg/kg for 3 days, (3) dose of 13.5 mg/kg, and (4) sham. Irradiated mice were exposed to 9.5 Gy whole body Co60 γ-radiation. MRI was performed with a high dose of manganese chloride (MnCl2) (150 mg/kg) to assess the distribution of the MnCl2. Results The mice have promising survival curves (highest survival—13.5 mg/kg dose over 3 days of MnCl2 at 80% [87% female, 73% male] P  = 0.0004). The complete blood count (CBC) results demonstrated a typical hematopoietic response in all of the irradiated groups, followed by mildly accelerated recovery by day 28 in the treated groups. No difference between groups was measured by Rota Rod, DigiGait, and Y-maze. Histologic evaluation of the bone marrow sections in the group given 13.5 mg/kg dose over 3 days had the best return to cellularity at 80%. MRI showed a systemic distribution of MnCl2. Discussion The preliminary data suggest that a dose of 13.5 mg/kg of MnCl2 given over 3 days prior to exposure of radiation may have a protective benefit while not exhibiting the neurobehavioral problems. A countermeasure that can prophylactically protect emergency personnel entering an area contaminated with high levels of radiation is needed, especially in light that nuclear accidents are a continued global threat. There is a need for a protective agent with easy long-term storage, easy to transport, easy to administer, and low cost. Histologic evaluation supports the promising effect of MnCl2 in protecting tissue, especially the bone marrow using the dose given over 3 days (4.5 mg/kg per day) of MnCl2. Conclusions Initial experiments show that MnCl2 is a promising safe and effective prophylactic countermeasure against ARS. MRI data support the systemic distribution of MnCl2 which is needed in order to protect multiple tissues in the body. The pathology data in bone marrow and the brain support faster recovery from radiation exposure in the treated animals and decreased organ damage. [ABSTRACT FROM AUTHOR]

To mitigate the effects of drought stress on fatty acid compositions and seed germination, various hypothesis have been studied by researchers. In this study, the field experiments were conducted in two cropping seasons (2020–2021) to investigate the effect of micronutrients on some characteristics of canola cultivars under late-season drought stress conditions. The experiments were arranged in a factorial split-plot design with three replications. The main factors included irrigation regimes (regular irrigation and irrigation interruption at the flowering stage) and foliar applications of Zn and Mn after rosette stage (F1: none application, F2: ZnSO4, F3: MnSO4, and F4: ZnSO4+MnSO4). The third factor included three cultivars, including Nima, R15 and KS7, as subfactor. Limited irrigation at flowering stage reduced length of seedling (25% and 17%), weight of seedling (30% and 14%), and seed yield (42% and 29) in first and second year, respectively. Irrigation withholding at flowering stage reduced seed yield by 37, 27, and 42% in R15, Nima and KS7 cultivars, respectively. Based on the current experimental data, irrigation withholding at flowering stage caused severe stress to the plants, especially those with long-term growth periods such as R15 and KS7. By contrast, the minimum yield loss was obtained from Nima cultivar, an early mature cultivar. Overall, it is recommended R15 cultivar for normal irrigation and Nima cultivar for a drought environment when considered the acceptable seed yield in new plants. In general, it is suggested that a suitable performance of canola seeds is achieved by foliar application of manganese and zinc. [ABSTRACT FROM AUTHOR]

The aviation sector is believed to be responsible for considerable environmental damage attributed to emission of a large number and amount of pollutants. Airports are often surrounded by forest fragments and humid areas that attract birds of prey and hence may potentially serve as useful bioindicators. The aim of the present study was to examine genotoxic potential in raptors exposed to airport pollution using the micronucleus (MN) test and morphological changes as evidenced by bilateral symmetry. This investigation was conducted at Salgado Filho International Airport of Porto Alegre – RS as well as in private and zoological breeding grounds. The presence of metals was measured in the blood cells of the collected birds. Seventeen birds (Caracara (Polyborus) plancus) were used in this study 11 from exposed and 6 from non-exposed group. The nuclear alterations clearly indicate that organisms exposed to airport pollution exhibited a significantly higher frequency of genetic damage compared to non-exposed birds. Further, manganese and chromium were detected exclusively in the blood of the exposed group. In contrast, the analysis of bilateral symmetry did not detect any significant morphologic differences between the two groups. Therefore, data indicate that blood genotoxic stress occurs in birds of prey living in civil aviation areas as evidenced by MN frequency increase and presence of manganese and chromium. [ABSTRACT FROM AUTHOR]

Manganese (Mn) is a heavy metal that occurs widely in nature and has a vital physiological role in growth and development. However, excessive exposure to Mn can cause neurological damage, especially cognitive dysfunction, such as learning disability and memory loss. Numerous studies on the mechanisms of Mn-induced nervous system damage found that this metal targets a variety of metabolic pathways, for example, endoplasmic reticulum stress, apoptosis, neuroinflammation, cellular signaling pathway changes, and neurotransmitter metabolism interference. This article reviews the latest research progress on multiple signaling pathways related to Mn-induced neurological dysfunction. [ABSTRACT FROM AUTHOR]

Background: The global market for lithium-ion batteries (LIBs) is growing exponentially, resulting in an increase in mining activities for the metals needed for manufacturing LIBs. Cobalt, lithium, manganese, and nickel are four of the metals most used in the construction of LIBs, and each has known toxicological risks associated with exposure. Mining for these metals poses potential human health risks via occupational and environmental exposures; however, there is a paucity of data surrounding the risks of increasing mining activity. The objective of this review was to characterize these risks. Methods: We conducted a review of the literature via a systematic search of the PubMed database on the health effects of mining for cobalt, lithium, manganese, and nickel. We included articles that (1) reported original research, (2) reported outcomes directly related to human health, (3) assessed exposure to mining for cobalt, lithium, manganese, or nickel, and (4) had an available English translation. We excluded all other articles. Our search identified 183 relevant articles. Results: Toxicological hazards were reported in 110 studies. Exposure to cobalt and nickel mining were most associated with respiratory toxicity, while exposure to manganese mining was most associated with neurologic toxicity. Notably, no articles were identified that assessed lithium toxicity associated with mining exposure. Traumatic hazards were reported in six studies. Three articles reported infectious disease hazards, while six studies reported effects on mental health. Several studies reported increased health risks in children compared to adults. Conclusions: The results of this review suggest that occupational and environmental exposure to mining metals used in LIBs presents significant risks to human health that result in both acute and chronic toxicities. Further research is needed to better characterize these risks, particularly regarding lithium mining. [ABSTRACT FROM AUTHOR]

Here we report a protocol for the preparation of 1,4‐diketones from 1,2‐disubstituted cyclobutanols based on their ring‐opening oxidation with molecular oxygen. The reaction proceeds under manganese catalysis in the presence of 1,10‐phenanthroline ligand and leads to the target product along with minor 4‐hydroxyketone that can be oxidized with Dess‐Martin periodinane in the same reaction vessel. Substrates with alkyl and aryl substituents including those bearing functional groups were successfully engaged in the reaction. [ABSTRACT FROM AUTHOR]

This study was conducted on the distribution of manganese content in the soils of the city of Mitrovica and its surroundings in Kosovo. A total of 156 topsoil samples were taken in the entire study region (sampling grid of 1.4 × 1.4 km2). The average Mn content of the entire study area is 1600 mg/kg (range 170–17000 mg/kg), which is 4.2 times higher than the EU average and 3.3 times higher than the global average. The spatial distribution maps show that the higher Mn contents occur mainly in soils from Miocene latite as well as quartz-latite and from Triassic volcanic-sedimentary formations in the eastern and north-eastern part of the study area. The lower values were found in the Flysch and Cretaceous flysch outcrops. It was found that the increased Mn contents in soils from this area are mostly of lithogenic origin. The values of the enrichment factor (EF) show that the soils of the entire study area are very highly enriched with Mn (20 < EF < 40). The values of the geo-accumulation index (1< I-geo ≤ 2), show that the soils of the entire study area are moderately contaminated with Mn. [ABSTRACT FROM AUTHOR]

Doping semiconductor nanomaterials with manganese ion (Mn2+) introduce a well‐defined photoactive d‐d level within the band structure, paving the way for diverse applications. Although Mn doping in single‐layer 2D hybrid perovskites (n = 1) has been extensively studied, limited research has been conducted on doping with modulation of the layer thickness. Herein, Mn2+ doping in hybrid 2D perovskite nanoplatelets (NPLs), L2An‐1[Pb1‐xMnx]nBr3n+1 (where L = butylammonium, A = methylammonium), with variations in Mn concentration (x = 0–0.60) and layer thickness (n = 1–3) is reported. Substitutional doping of Mn significantly increases the photoluminescence quantum yield as well as the rate of energy transfer efficiency, which strongly depends on the layer thickness of NPLs. The Mn concentration in 2D NPLs determines the rate of forward and backward energy transfer. Low‐temperature emission spectra allow to determine thickness‐dependent exciton binding energy for Mn‐doped 2D NPLs (x = 0.5) with values of 410 ± 11 meV (n = 1), 188 ± 9 meV (n = 2), and 151 ± 17 meV (n = 3). The faster dissociation of band‐edge excitons into free carriers at Mn2+ sites results in high brightness with an excellent CRI of 89.2 for the white light‐emitting diode. [ABSTRACT FROM AUTHOR]

In this paper, we report an inexpensive one-step synthesis of self-supported 3D nickel-manganese (NiMn) bimetallic coatings and their application for the hydrogen evolution reaction in simulated seawater (1 M KOH + 0.5 M NaCl) and alkaline natural seawater (1 M KOH + natural seawater). These binary coatings were electrodeposited on a titanium substrate using a facile electrochemical deposition method by a dynamic hydrogen bubble template technique. The as-deposited NiMn coatings with variable Mn amounts produce typical globular and unique porous architecture with abundant pores of different sizes. The activity of these fabricated catalysts towards the hydrogen evolution reaction was investigated by linear sweep voltammetry towards simulated seawater and alkaline natural seawater at different temperatures. The surface morphology and composition of the catalysts were also characterized by scanning electron microscopy and inductively coupled plasma optical emission spectroscopy. The as-prepared NiMn/Ti electrocatalyst, which was electrodeposited using a chemical bath containing Ni2+ and Mn2+ ions with a molar ratio of Ni2+:Mn2+ = 1:5, exhibits excellent hydrogen evolution activity in simulated seawater with an ultra-low overpotential of 64.2 mV to reach a current density of 10 mA cm−2. It is noteworthy that this NiMn/Ti electrocatalyst also achieves a current density of 10 mA cm−2 in alkaline natural seawater with a comparably low overpotential of 79.3 mV. The current densities increase by ca. 1.75–2.35 times with an increase in temperature from 25 °C to 75 °C for hydrogen evolution in both electrolytes. This bimetallic catalyst has shown excellent long-term stability at a constant potential of −0.23 V (vs. RHE) and a constant current density of 10 mA cm−2 for 10 h, which ensures higher durability and robustness for practical application of seawater splitting technology. [Display omitted] • 3D bimetallic NiMn/Ti electrocatalysts synthesized using a dynamic hydrogen bubble template technique. • Efficient and stable 3D bimetallic NiMn/Ti electrocatalysts for HER in simulated seawater/alkaline natural seawater. • NiMn/Ti-5 shows excellent HER activity with overpotentials of 64.2 and 79.3 mV at 10 mAcm−2 in simulated and natural seawater. • Simple, non-toxic, affordable, and time-saving synthesis procedure. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objectives: Experimental and acute exposure studies imply that manganese affects red blood cell production. Nevertheless, the association between environmental exposure and red blood cell distribution width (RDW) has yet to be explored. This research sought to assess the correlation between blood manganese levels and RDW within the general population of the United States. Materials and methods: Employing weighted multiple linear regression models, data from the 2011–2018 National Health and Nutrition Examination Survey (NHANES) were utilized to assess the correlation between manganese levels in the blood and RDW. Restricted cubic spline plots and two-piecewise linear regression models were also employed. Result: The analysis included a total of 15882 participants in which we determined an independent positive relationship between blood manganese levels and RDW among participants(β = 0.079, P<0.001). Moreover, we identified a J-shaped association between blood manganese levels and RDW in total participants (inflection point for blood manganese: 7.32 ug/L) and distinct subgroups following adjusted covariates. Women exhibited a more pronounced association, even after controlling for adjusted covariates. Conclusions: We determined a J-shaped relationship between blood manganese levels and RDW with an inflection point at 7.32 ug/L for blood manganese. Nevertheless, fundamental research and large sample prospective studies are needed to determine the extent to which blood manganese levels correlate with RDW. [ABSTRACT FROM AUTHOR]

The Mn(III)-based oxidation of 1,3-indanedione (1) with 1,1-diarylethenes 2a–c effectively proceeded in boiling AcOH to produce 2,2-bis(vinyl)indanediones 5a–c and 1,2'-spirobi[indene]-1',3'-diones 6a–c via the formation of 2,2-bis(2-acetoxyethyl)indanedione 3 and acetoxyindeno[1,2-b]furan-4-one 4 intermediates. On the other hand, the Mn(III)-based aerobic oxidation of 1a with 2a at room temperature resulted in bis(endoperoxide) 8a and endoperoxypropellane 9a via the production of mono(endoperoxide) 7a. The plausible reaction pathways were also discussed. [ABSTRACT FROM AUTHOR]

In this study, Sorel cement (SC) was doped with Mn7+ to develop a cost-effective adsorbent that can quickly remove methylene blue (MB) dye from aqueous solutions. The characteristics of the prepared adsorbents were examined using X-ray diffraction, atomic force microscopy, scanning electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The examinations confirmed the formation of SC and the successful doping of manganese. Batch adsorption experiments were also performed to investigate and to optimise the operational parameters such as Mn7+ ion concentration, contact time, dosage, MB concentration, pH, and temperature. The modified adsorbent revealed a significant adsorption improvement when compared with pure SC. A small addition of 0.01 g of Mn7+ exhibited 100% removal efficiency up to a dye concentration of about 100 mg/L, whereas about 64% removal efficiency was obtained with pure SC using 36.5 mg/L of the MB solution. Furthermore, the modified adsorbent revealed rapid equilibrium times of around 1 and 3 minutes using 36.5 and 100 mg/L of the MB solution, respectively. An experimental adsorption capacity of up to 246 mg/g was obtained, and the equilibrium data were consistent with the Freundlich isotherm and were well fitted with a pseudo-second-order kinetic model. The thermodynamic values indicated a physisorption, exothermic (ΔH° = −7.7 kJ/mol), and spontaneous (ΔG° = −9.4 kJ/mol) nature of the adsorption process with enhanced feasibility and comparable regeneration efficiency for up to five cycles. Therefore, the results indicate that the modified sorbent can possibly be utilised as a potential fast method for the removal of MB dye from wastewater. [ABSTRACT FROM AUTHOR]

In this work, manganese whitlockite (Mn-WH, Ca 18 Mn 2 (HPO 4) 2 (PO 4) 12) was successfully synthesized and comprehensively characterized. This material is a manganese-containing analog of the biomineral magnesium whitlockite (Mg-WH, Ca 18 Mg 2 (HPO 4) 2 (PO 4) 12). The synthesis was performed via a low-temperature dissolution-precipitation process in aqueous medium under ambient pressure at 75 °C using dicalcium phosphate dehydrate and manganese acetate tetrahydrate as starting materials. The crystal structure of the synthesized powder was determined by powder X-ray diffraction, FTIR and Raman spectroscopies, demonstrating the presence of characteristic structural units. Morphological features and elemental distribution within the synthesized powder were studied by SEM/EDX analysis. XPS, EPR and magnetic studies confirmed the presence of Mn ions in a divalent state. Temperature-dependent magnetic measurements revealed a paramagnetic behavior of Mn-WH down to 5 K. In vitro cytotoxicity experiments were performed with MC3T3-E1 preosteoblastic cell line. [ABSTRACT FROM AUTHOR]

A homogeneous catalyst system consisting of Mn(OAc)2 and 2‐picolinic acid was studied for alcohol oxidation using peracetic acid as the oxidant. Catalyst loadings as low as 0.01 mol% could be utilized and the system compared well to other peroxide based methods. The utilization of continuous flow allowed the fast, exothermic reactions to be carried out in a safe and scalable manner. [ABSTRACT FROM AUTHOR]

From organs to subcellular organelles, trace element (TE) homeostasis is fundamental for many physiological processes. While often overlooked in early stages, manifested TE disbalance can have severe health consequences, particularly in the context of aging or pathological conditions. Monitoring TE concentrations at the mitochondrial level could identify organelle-specific imbalances, contributing to targeted diagnostics and a healthier aging process. However, mitochondria isolation from frozen tissue is challenging, as it poses the risk of TE losses from the organelles due to cryodamage, but would significantly ease routine laboratory work. To address this, a novel method to isolate an enriched mitochondria fraction (EMF) from frozen tissue was adapted from already established protocols. Validation of manganese (Mn), iron (Fe), and copper (Cu) quantification via inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) showed sufficiently low quantification limits for EMF TE analysis. Successful mitochondrial enrichment from frozen liver samples was confirmed via immunoblots and transmission electron microscopy (TEM) revealed sufficient structural integrity of the EMFs. No significant differences in EMF TEs between frozen and fresh tissue were evident for Mn and Cu and only slight decreases in EMF Fe. Consequently, EMF TEs were highly comparable for isolates from both tissue states. In application, this method effectively detected dietary differences in EMF Fe of a murine feeding study and identified the disease status in a Wilson disease rat model based on drastically increased EMF Cu. In summary, the present method is suitable for future applications, facilitating sample storage and high-throughput analyses of mitochondrial TEs. [ABSTRACT FROM AUTHOR]

Globally, scale deposition in water supply pipelines is one of the major problems faced by water utilities. This research aimed to determine the causes and effects of scale deposition in the water supply pipelines in Surakarta City, Indonesia. The total dissolved solids (TDS), hardness, manganese, and alkalinity in groundwater were higher than those in the surface water and spring water; thus, the supply areas from groundwater were identified using TDS at the taps. The three scaling indicators, i.e., the Langelier saturation index (LSI), the Ryznar stability index (RSI), and the Puckorius scaling index (PSI), indicated moderate calcium carbonate scaling. However, elemental analysis of eight scale samples using X-ray fluorescence (XRF) revealed that the major components of scale were either manganese (50.1–80.8%) or iron (45.6–63.8%), whereas calcium (3.0–7.8%) was a minor component. Because only five of twenty groundwater sources were chlorinated before distribution, it is estimated that dissolved manganese is oxidized by manganese-oxidizing bacteria. The manganese deposition rate in the networks was estimated to be 1660 kg/year using the manganese concentration at groundwater sources and in customers' taps. These results suggest the importance of the elemental analysis of scale and avoidance of overreliance on scale indicators. [ABSTRACT FROM AUTHOR]

Chemoselective hydrogenation of α,β‐epoxy ketones and α‐ketoamides is achieved at room temperature (25 °C) using 2.0 bar H2 and a pincer‐ligated Mn(I) catalyst that provides synthetically valuable α‐hydroxy epoxides and α‐hydroxy amides. This protocol applies to a wide range of alkyl‐ and aryl‐substituted α,β‐epoxy ketones, including terpenes (α‐ionone, nootkatone, and R‐carvone)‐ and steroids (testosterone and progesterone)‐derived epoxy ketones, and tolerates H2 sensitive functionalities, such as halides, acetyl, nitrile, nitro, epoxide, alkenyl and alkynyl groups. Additionally, α‐ketoamides bearing reducible functional groups, including acetyl and diazo benzene, were untouched under this protocol and selectively converted to α‐hydroxy amides. A preliminary mechanistic study highlighted the metal‐ligand cooperative H2 activation process. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSIONS An issue of pressing concern is the manganese contamination in farmland soils adjacent to industrial areas. To address this, intercropping hyperaccumulator plants with crops emerges as a sustainable approach to ensuring food security. This study aims to investigate the influence of intercropping Sedum alfredii with maize or soybean on their growth and the dynamics of manganese accumulation through field experiments.The results showed that compared with monoculture, the Sedum alfredii–maize intercropping system exhibited a land equivalent ratio (LER) of 1.89, signifying a 71.13% augmentation in bioaccumulation amount (BCA). Additionally, it led to a significant reduction in manganese content in various organs, ranging from 17.05% to 25.50%. However, the Sedum alfredii–soybean intercropping system demonstrated a LER of 1.94, accompanied by a 66.11% increase in BCA, but did not significantly reduce the manganese content in the roots, stems, and pods of soybeans. Furthermore, manganese accumulation in maize and soybean grains was primarily attributed to the aboveground translocation of manganese. The intercropping effect on blocking manganese absorption of maize during growth and maturity is primarily attributed to the earlier manganese accumulation in intercropped maize by 2.63 to 4.35 days, and a reduction of 21.95% in the maximum manganese accumulation rate.The study found that manganese accumulation dynamics vary significantly depending on the crop family. Intercropping Sedum alfredii with maize enhances land‐use efficiency and reduces manganese uptake by crops, making it a promising strategy for remediating manganese‐contaminated farmland near industrial areas. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Regulating the intrinsic activity of electrocatalysts is an effective strategy towards outstanding behaviour for oxygen evolution reaction (OER). Herein, the rational design of a Mn–CoP@CoFe 2 O 4 core-shell heterojunction using nickel foam (NF) as a supporting material with special interface engineering has been investigated by a facile hydrothermal technique combined with phosphorization and electrodeposition method. The physical characterization demonstrates Mn–CoP@CoFe 2 O 4 core-shell heterostructure with Mn–CoP nanoneedles as core and CoFe 2 O 4 nanosheets as shell has been successfully acquired. The electrochemical measurements of the as-prepared Mn–CoP@CoFe 2 O 4 /NF core-shell heterojunction nanoarray electrode exhibit the superior electrocatalytic behaviour for OER (Tafel slope of 35.6 mV dec−1 and overpotential of 209.6 mV@10 mA cm−2). The remarkable OER behaviour may be ascribed to the sufficient active sites and the enhanced intrinsic activity due to the introduction of CoFe 2 O 4 and Mn element, which can regulate the electron structure and increase the turnover frequency. Furthermore, the Mn–CoP@CoFe 2 O 4 /NF electrode appears an excellent long-run stability during the OER process at 100 mA cm−2 for 100 h. Therefore, the construction of metal doping transition metal-based core-shell heterostructure electrocatalysts may be a promising way for the remarkable OER electrocatalytic performance towards water splitting. Mn–CoP@CoFe 2 O 4 core–shell heterostructure electrocatalyst revealed the remarkable OER behaviour and stability, ascribing to the sufficient active sites and the enhanced intrinsic activity by the introduction of CoFe 2 O 4 and Mn element, which can regulate the electron structure and increase the turnover frequency. [Display omitted] • Mn–CoP@CoFe 2 O 4 /NF core-shell heterostructure electrocatalyst was fabricated. • Mn–CoP@CoFe 2 O 4 /NF exhibited the outstanding OER behaviour in 1 M KOH. • Mn–CoP@CoFe 2 O 4 /NF electrode appeared an excellent long-run stability for OER in 100 mA cm−2 for 100 h. • Mn–CoP@CoFe 2 O 4 /NF electrode possessed sufficient active sites and enhanced intrinsic activity. [ABSTRACT FROM AUTHOR]

The relationship between slag structure and viscosity is studied, employing Raman spectroscopy for the five-component slag system of MnO-SiO2-CaO-Al2O3-MgO and its subsystems. This study aims to investigate the influence of variations in slag composition on viscosity, which is crucial for optimizing industrial processes. Based on industrial slag compositions produced in a silicomanganese submerged arc furnace, 17 slags with a fixed content of MnO of 10 wt% are synthesized with varying contents of SiO2 of 33 to 65 wt%; CaO within the range of 14 to 40 wt%; and fixed contents of Al2O3 and MgO of 17 and 6 wt%, respectively. The slag compositions are divided into four groups, ranging from low basicity (0.38) to high basicity (0.80), with each group containing the four slag systems of MnO-SiO2-CaO, MnO-SiO2-CaO-Al2O3, MnO-SiO2-CaO-MgO, and MnO-SiO2-CaO-Al2O3-MgO, with fixed basicity. Additionally, a five-component composition with the lowest basicity of 0.28 is considered. Raman spectroscopy measurements are performed in the wavenumber range of 200 to 1200 cm − 1 using a green source laser with a 532 nm wavelength. The high-wavenumber region of the Raman spectra (800 to 1200 cm − 1 ) is deconvoluted to quantitatively investigate the effect of each oxide on the slag structure and the degree of polymerization (DOP) of the silicate network. Results indicate that measured NBO/T increases with increasing basicity, demonstrating a reduction in DOP of the silicate structure. This depolymerization effect is more pronounced in slags containing Al2O3 compared to those without it. In a group of slags with similar basicity, the substitution of SiO2 with Al2O3 leads to further depolymerization. In contrast, substituting CaO with MgO has little effect on the silicate structure in slags without Al2O3 but causes depolymerization in slags containing Al2O3. To study the relationship between structure and viscosity, viscosity data obtained from FactSage are used as reference values. The predictions of slag viscosity using the Raman-structure model and the NBO/T viscosity model are then compared to the FactSage results. The adjustable parameters of the Raman-structure model are re-determined using the FactSage data for the studied slag compositions. The NBO/T viscosity model employs both calculated NBO/T values from the slag compositions and measured NBO/T values from the deconvolution results. The findings of this study reveal good agreement between the predictions of the Raman-structure model and the FactSage viscosity data. [ABSTRACT FROM AUTHOR]

The electrochemical behavior of manganese silicide-germanides with different ratios of germanium and silicon is studied using the methods of voltammetry and impedance spectroscopy in 0.5 M aqueous sodium sulfate solution. It is shown that the oxidation stability of materials decreases with an increase in the ratio of germanium, which, unlike silicon, is incapable of forming a layer of stable oxides on the material surface. [ABSTRACT FROM AUTHOR]

A new bidentate Schiff base ligand (C16H16Cl2N4), condensation product of ethylene diamine and 4-chloro N-phenyl formamide, and its metal complexes [M(C16H16Cl2N4)2(OAc)2] (where M = Mn(II) and Zn(II)) were synthesized and characterized using various analytical and spectral techniques, including high-resolution mass spectrometry (HRMS), elemental analysis, ultraviolet-visible (UV-vis), Fourier-transform infrared (FTIR) spectroscopy, AAS, molar conductance, 1H NMR, and powder XRD. All the compounds were non-electrolytes and nanocrystalline. The synthesized compounds were assessed for antioxidant potential by DPPH radical scavenging and FRAP assay, with BHT serving as the positive control. Inhibitory concentration at 50% inhibition (IC50) values were calculated and used for comparative analysis. Furthermore, the prepared compounds were screened for antibacterial activity against two Gram-negative bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram-positive bacteria (Escherichia coli and Salmonella typhi) using disk-diffusion methods, with amikacin employed as the standard reference. The comparison of inhibition zones revealed that the complexes showed better antibacterial activity than the ligand. To gain insights into the molecular interactions underlying the antibacterial activity, the ligand and complexes were analyzed for their binding affinity with S. aureus tyrosyl-tRNA synthetase (PDB ID: 1JIL) and S. typhi cell membrane protein OmpF complex (PDB ID: 4KR4). These analyses revealed robust interactions, validating the observed antibacterial effects against the tested bacterial strains. [ABSTRACT FROM AUTHOR]

The phase composition of the pre-oxidized film on an alloy surface usually has a great influence on its corrosion resistance. In this work, the surface oxide film growth behavior in low-oxygen atmosphere at 720 °C of two 12Cr heat-resistant steels with different Mn content was studied, and their corrosion resistance in liquid lead–bismuth eutectic (LBE) with saturated oxygen at 600 °C was tested. The results indicated that the pre-oxidized film of 1.6Mn steel is mainly composed of large-size Mn–Cr spinel and Fe–Cr spinel, while that of improved 0Mn steel is mainly composed of continuous and dense Cr2O3 and Fe–Cr spinel. This is because Mn has a high diffusion rate in Cr2O3, so it can pass through the Cr2O3 layer and combine with O to form Mn-rich oxides, and then the Mn-rich oxides react with Cr2O3 to form Mn–Cr spinel. However, due to the high solubility of Mn in LBE, the Mn-rich pre-oxidized film of 1.6Mn steel will dissolve and fail quickly, so its long-term corrosion resistance in LBE is lower than that of 0Mn steel. [ABSTRACT FROM AUTHOR]

The increasing global demand for Mn necessitates cost-effective recovery methods applicable to low- and medium-grade ores. Reductive bioleaching has emerged as a promising technique for Mn extraction from low-grade ores. This study aimed to simultaneously bioleach both Cu and Mn from low-grade ore obtained from Boleo, Mexico, using Acidithiobacillus thiooxidans. Additionally, the influence of activated coffee charcoal on the leaching process was examined. The biotic samples exhibited significantly higher Cu (70.6–71.9%) and Mn (78.8–82.2%) extraction compared to abiotic samples (41.7% Cu and 2.7% Mn). The presence of activated coffee charcoal improves the extraction rate and leaching efficiency of Mn, but it does not significantly impact Cu bioleaching from low-grade ore. Additional experiments confirmed that sulfur oxidation by A. thiooxidans played a significant role in Mn dissolution. A. thiooxidans oxidizes elemental sulfur, and during this process, Mn undergoes reduction either through enzymatic or non-enzymatic pathways. After the bioleaching process, the majority of Cu and Mn in the aqueous phase, and Cu and Mn within the residual ore can also be easily leached in a weak acid environment. This study demonstrates the applicability of simultaneous bioleaching without the necessity of an additional chemically reducing agent, effectively contributing to metal extraction practices. Further optimization of operational parameters, including sulfur concentration and operation time, is necessary to enhance leaching efficiency before the scaling-up of the approach validated in the presented study. [ABSTRACT FROM AUTHOR]

The studies are focused in the Mara–Kamenka–Uvat interfluve of the Biryusa Uplift of the basement of the Siberian Platform, where the Mara paleovolcano was recognized during the prospecting works for manganese more than 50 years ago. The specific volcano-sedimentary rocks are considered in the structure of the Late Riphean Karagas Group. Our mineralogical and petrographic studies allowed us to establish abundant high-K pyroclastic rocks, ignimbrites, and trachybasalts, which indicate a subaerial explosive character of the Mara volcano. The age of high-K volcanism of 640 Ma is based on U–Th–Pb dating of zircon. The Lu–Hf isotope systematics of zircon indicates a link of volcanism with mantle magmas. The composition and the period of the formation of rocks prevent their correlation (as was considered before) with sedimentary Late Riphean quartz and quartz–feldspar sandstones of the Karagas Group and dolerites of the Nersa intrusive complex. Specific mineralogical–petrographic features of rocks allow their use as a regional stratigraphic reference. [ABSTRACT FROM AUTHOR]

Melanoma is a highly malignant and drug-resistant disease that imposes a substantial economic burden on the world. There are many studies linking trace elements to diverse types of cancers, including melanoma. This review elucidates the relationship between trace elements exposure and melanoma. It was identified that copper, manganese, selenium, zinc, iron, and many other trace elements were associated with melanoma in humans. In terms of epidemiology, different elements have different correlations with melanoma. These trace elements affect the occurrence and development of melanoma through various mechanisms, such as oxidative stress and the MAPK pathway. The literature on the role of trace elements in the pathogenesis and treatment of melanoma depicts promising prospects for this field. [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate the heavy metal pollution status of the agricultural soils in Ramhormoz Plain, Khuzestan province, Iran. A total of 54 samples from the depths (0–20 cm) of the soil were collected from the selected areas in (March) 2021. According to the obtained results, the concentrations of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn, Al in soil samples were 1.3, 0.68, 60, 10.6, 0.01, 218, 23, 3.65, 14 and 0.58 mg/kg, respectively, in which As showed significant soil contamination and Cu, Hg, Mn, Ni, Pb, Zn and Al moderate contamination according to the calculation of contamination factor (CF). PCA analysis revealed that both anthropogenic and natural sources of pollution like agricultural and transport activities contributed to the enrichment of study area. Investigation of ecological risk indicated that Ramhormoz Plain was categorized as a high risk area. [ABSTRACT FROM AUTHOR]

• The enrichment of iodine in the groundwater within an acid and reducing environment is investigated in the Pearl river delta, China. • The redox of MnO 2 and iodide resulted in the formation of iodine and iodate, which can be effectively adsorbed on soil. • By improving the concentration of dissolved oxygen in groundwater can immobilize the iodine species in soils to a greater extent. In North China, iodine-rich groundwater has been extensively studied, but few in South China. This study aimed to investigate the characteristics of iodine-rich groundwater in South China and identify potential contamination sources. The results revealed that the average concentration of iodine in groundwater was 890 µg/L, with a maximum concentration of 6350 µg/L, exceeding the permitted levels recommended by the World Health Organization (5–300 µg/L). Notably, the enrichment of iodide occurred in acidic conditions (pH = 6.6) and a relatively low Eh environment (Eh = 198.4 mV). Pearson correlation and cluster analyses suggested that the enrichment of iodide could be attributed to the intensified redox process involving Mn(II), iodine (I 2), or iodate (IO 3 −) in the soil. The strong affinity between Mn(II) and I 2 /IO 3 − facilitated their interaction, resulting in the formation and mobilization of I− from the soil to the groundwater. Leaching experiments further confirmed that reducing substances (such as sodium sulfides, ascorbic acids, and fulvic acids) in the soil with low dissolved oxygen (DO) levels (< 1.0 mg/L) enhanced the dissolution of iodine species. Conversely, higher DO content (> 3.8 mg/L) promoted the oxidation of I− into I 2 or IO 3 −, leading to its stabilization. This research provides new insights into the characteristics and mechanisms of I− enrichment in groundwater in South China, and emphasizes the significance of the redox reactions involving Mn(II) and I 2 /IO 3 −, as well as the influence of soil properties in regulating the occurrence and transportation of iodine species within groundwater systems. [Display omitted] [ABSTRACT FROM AUTHOR]

The perfect strategy for the generation of green and renewable hydrogen (H2) fuels is the direct electrocatalytic splitting of plentiful seawater rather than scarce freshwater. One of the half-reactions taking place during the electrocatalytic splitting of seawater is oxygen evolution (OER). However, the OER is affected by slow four-electron transfer kinetics as well as competitive chlorine evolution reactions (CERs) in seawater. To overcome the kinematic and competitive barriers of seawater splitting and achieve an excellent overall performance of seawater splitting, we herein report a facile, low-cost, one-step fabrication procedure of 3D structured nickel–manganese (NiMn) coatings using a dynamic hydrogen bubble template (DHBT) technique. The electrocatalytic activities of the thus synthesized catalytic materials for OER in simulated seawater (0.5 M NaCl + 1 M KOH, denoted as SSW) and alkaline natural seawater (natural seawater + 1 M KOH, denoted as ASW) were investigated using linear sweep voltammetry (LSV) at varying temperatures from 25 to 75 °C. Scanning electron microscopy (SEM) and inductively coupled plasma–optical emission spectroscopy (ICP–OES) were used to examine the surface morphology and composition of the prepared catalysts. It was found that the prepared NiMn/Ti-1 catalyst in a plating bath containing a molar ratio of 1:1 Ni2+:Mn2+ and having the lowest Mn loading of 13.43 µg cm−2 exhibited quite reasonable activity for OER in Cl− ion rich SSW and ASW. To achieve the benchmark current density of 10 mA cm−2 in SSW and ASW, the NiMn/Ti-1 electrocatalyst requires overpotentials of 386 and 388 mV, respectively. In addition, this optimal bimetallic electrocatalyst also demonstrated superior long-run stability at 1.81 V (vs. RHE) and 10 mA cm−2 for 24 h in both working electrolytes. Impressively, the two-electrode electrolyzer—NiMn/Ti-5(−)||NiMn/Ti-1(+)—needs only 1.619 V to deliver 10 mA cm−2 current density for overall alkaline seawater electrolysis, which is even 0.075 V lower than the noble metal-based electrolyzer (Pt(−)||NiMn/Ti-1(+)). [ABSTRACT FROM AUTHOR]

For efficient lithium recovery, the electrochemical lithium recovery (ELR) process that uses LiMn2O4 (LMO) electrodes with selectivity for lithium ions, has been introduced. The electrochemical system is environmentally friendly and allows for the recovery of lithium at a high yield, but the issue of manganese dissolution in LMO electrodes, decreasing their stability, remains to be solved. Herein, we suggest a solution to the existing problem through a rapid lithium recovery method that also enhances the stability of LMO electrodes through the state-of-charge (SoC) control approach. The retained discharge capacity of the system with a high current density (0.4 A/g) remains at 99.2% at 60% SoC after 300 cycles. Compared to the results under full charge/discharge operation (44.2% after 300 cycles), the proposed method demonstrates the state-of-charge (SoC) control adjustments at high current density levels to enhance the recovery rate and stability of the electrode. Additionally, high lithium-ion selectivity with a similar recovery rate is maintained at a high current density under 60% SoC operation compared to 100% SoC in lithium recovery tests. These results indicate that the SoC control strategy can increase the efficiency of ELR by improving the stability of the electrode under high-rate operational condition [ABSTRACT FROM AUTHOR]

Manganese dioxide in pyrolusite was directly reduced to manganese sulfate by high-temperature roasting with ammonium sulfite as reducing agent, so as to achieve efficient extraction of pyrolusite. The effects of mass ratio of ammonium sulfite to pyrolusite, roasting temperature and time, leaching temperature and time on the extraction rate of manganese were investigated, and the optimum process conditions were determined. The results show that the optimal conditions are the mass ratio of ammonium sulfite to pyrolusite of 0.75:1, roasting temperature of 500 °C, roasting time of 1.5 h, leaching temperature of 25 °C, leaching time of 30 min. Under the conditions, the leaching rate of manganese and iron is about 93% and about 9.5%, respectively. The extraction effect of manganese is good. [ABSTRACT FROM AUTHOR]

BACKGROUND: Nail salon technicians are susceptible to potential exposure to a diverse array of hazardous chemicals in the form of dust or vapors. One of the main routes of exposure is dermal contact. OBJECTIVE: The aim of present study was to health risk assessment of dermal exposure to dust containing heavy metals in nail salon technicians. METHODS: Dust sampling was done on the work surface of 20 available nail salon technicians. The concentration of five metals including cadmium, lead, chromium, nickel, and manganese were determined using ICP-MS. Afterwards, the United States Environmental Protection Agency (USEPA) guideline was used to estimate the potential health risks, including carcinogenic and non-carcinogenic risks, associated with the analyzed metals. RESULTS: Results indicated the mean concentrations of Pb, Cd, Ni, Cr and Mn were 0.7953±0.4373, 0.0952±0.0264, 0.7666±0.8629, 0.4900±0.5994 and 1.134±0.4736, respectively. The hazard quotient (HQ) of all metals was within the permissible value, while hazard index (HI) was greater than 1. The probability of cancer risk (CR) resulting from dermal exposure to Ni, Cd and Cr exceeded the acceptable risk levels (10-6–10–4), but CR calculated for Pb was less than allowable value. CONCLUSION: Implementation of engineering controls such as downdraft vented nail tables and portable source capture systems is necessary. Besides, the use of personal protective equipment such as disposable nitrile gloves, N95 respirator masks, and ensuring proper training on safe work practices is recommended. [ABSTRACT FROM AUTHOR]

Lithium manganese phosphate (LiMnPO4) has been considered as promising cathode material for electric vehicles and energy storage. However, its durability and capability still face challenges. The first‐principles calculations are a powerful tool to explore the fundamentals of LiMnPO4 cathode materials. Hereby, the recent advances and prospects in the application of first‐principles calculations boosting LiMnPO4 cathode material for lithium‐ion batteries are analyzed and reviewed. Based on the results from density functional theory calculation and experimental research verification, the micromechanism research progress of the influence of ion doping on the electronic conductivity, lithium‐ion diffusion, working voltage, and stability of LiMnPO4 are summarized in detail. On top of a brief outlook, further elaboration is made on the direction of continuing relevant research. [ABSTRACT FROM AUTHOR]

Plutonium oxalate supernatant requires a treatment step for further recovery of the residual Pu. As the oxalate ion present in the solution poses problems during the recovery of Pu, it needs to be destroyed. In the present work, Mn2+ based catalytic destruction of oxalate ion was studied in detail, as it could minimize the generation of secondary radioactive waste compared to the conventional process. The effect of various parameters, namely concentrations of HNO3, catalyst, oxalic acid and effect of the metal ion has been studied. Moreover, the robustness of the catalytic destruction method along with the kinetics of oxalate destruction reaction has been investigated. The process was also demonstrated with Pu supernatant generated from CORAL at 1 L scale. [ABSTRACT FROM AUTHOR]