Alum Research Articles

Loss of Chromium(III) From Mixed Cr(III), Fe(III) Serum Transferrins

Abstract Objectives Transferrin, Tf, the protein that transports iron as Fe(III) from the blood to the tissues via endocytosis, is believed to also transport chromium(III), Cr(III). Under physiological conditions, Tf binds and releases Cr(III) rapidly from Cr(III)2-Tf; however, the major form of Tf in the bloodstream is mono-ferric Tf. Given the low concentration of Cr(III) in the bloodstream, the form of Cr(III)-containing Tf that is transported is probably monochromic, monoferric-Tf (Cr(III), Fe(III)-Tf). Given that Tf has two specific metal-binding sites, one in both its C-terminal and the N-terminal lobe, two forms of Cr(III), Fe(III)-Tf can form. The loss of Cr(III) from both forms of Cr(III), Fe(III)-Tf has been examined for the first time. Methods Cr(III), Fe(III)-Tf with Cr(III) in the C-lobe was prepared by adding CrCl3 to N-lobe monoferric Tf in deionized H2O at pH 7.5 containing ∼20 mM bicarbonate. Cr(III), Fe(III)-Tf with Cr(III) in the N-lobe was prepared by adding 1 equivalent of Fe as ferrous ammonium sulfate to Cr(III)2-Tf in 0.1 M HEPES buffer solution with 25 mM bicarbonate at pH 7.4. To examine the release of Cr(III), the pH of solutions of Cr(III), Fe(III)-Tf were acidified from pH 7.4 to pH 5.5. After time intervals, aliquots were removed and frozen for analysis by electron paramagnetic resonance (EPR) spectroscopy, which can distinguish aquated Cr(III) and Cr(III) bound to each of the two metal binding sites of Tf. Results The acidification of solutions of Cr(III), Fe(III)-Tf's in 100 mM HEPES and 25 mM bicarbonate solution, pH 7.4 to pH 5.5 resulted in a rapid loss of Fe(III) followed by a slower loss of Cr(III). The loss of Cr(III) from the Cr(III), Fe(III)-Tf with Cr(III) in the C-lobe is about 4 times faster than that from the same site in Cr(III)2-Tf. For the other site, the Cr loss is about 28 times faster. Thus, having one site vacant from the loss of Fe(III) leads to faster loss of Cr(III) from both lobes, suggesting Cr(III) loss is cooperative. Conclusions Mixed-metal Cr(III), Fe(III) Tf's loose Cr(III) for both metal binding sites in similar fashions to Cr(III) losses from Cr(III)2-Tf. Cr(III) is probably transported as mixed Cr(III), Fe(III)-Tf's. Funding Sources The University of Alabama Bioinorganic Chemistry of Chromium Research Fund.

Interfacial Reinitiation of Free Radicals Enables the Regeneration of Broken Polymeric Hydrogel Actuators

Interfacial Reinitiation of Free Radicals Enables the Regeneration of Broken Polymeric Hydrogel Actuators

A Protocol for Immunohistochemistry and RNA In-situ Distribution within Early Drosophila Embryo.

Calcium induced calcium release signaling (CICR) plays a critical role in many biological processes. Every cellular activity from cell proliferation and apoptosis, development and ageing, to neuronal synaptic plasticity and regeneration have been associated with Ryanodine receptors (RyRs). Despite the importance of calcium signaling, the exact mechanism of its function in early development is unclear. As an organism with a short gestational period, the embryos of Drosophila melanogaster are prime study subjects for investigating the distribution and localization of CICR associated proteins and their regulators during development. However, because of their lipid-rich embryos and chitin-rich chorion, their utility is limited by the difficulty of mounting embryos on glass surfaces. In this work, we introduce a practical protocol that significantly enhances the attachment of Drosophila embryo onto slides and detail methods for successful histochemistry, immunohistochemistry, and in-situ hybridization. The chrome alum gelatin slide-coating method and embryo pre-embedding method dramatically increases the yield in studying Drosophila embryo protein and RNA expression. To demonstrate this approach, we studied DmFKBP12/Calstabin, a well-known regulator of RyR during early embryonic development of Drosophila melanogaster. We identified DmFKBP12 in as early as the syncytial blastoderm stage and report the dynamic expression pattern of DmFKBP12 during development: initially as an evenly distributed protein in the syncytial blastoderm, then preliminarily localizing to the basement layer of the cortex during cellular blastoderm, before distributing in the primitive neuronal and digestion architecture during the three-gem layer phase in early gastrulation. This distribution may explain the critical role RyR plays in the vital organ systems that originate in from these layers: the suboesophageal and supraesophageal ganglion, ventral nervous system, and musculoskeletal system.

Improved modelling of magnetic splitting in a chrome alum below 300 mK

Chrome-Caesium Alum (CCA) is a paramagnetic salt that can be used to achieve ultra-low temperature refrigeration through adiabatic demagnetization. Cooling capacity measurements of CCA show a significant reduction below the isolated paramagnetic spin model for temperatures below 100 mK. A more complete understanding of the thermodynamic properties of CCA could improve model accuracy, vital for meeting cooling requirements at subKelvin temperatures. Modelling effort was undertaken to understand the physical origin of this reduction in heat and refrigeration capacity, and measurements from two separate CCA salt pills between 50 mK and 300 mK were used for model validation. Both the model and the experimental design and results are discussed in this work. The model uses exact eigenvalues for the Cr3+ ions from the spin Hamiltonian. Two interactions of interest are the zero-field splitting and hyperfine splitting, as these are not standard in presently used models.We found that, though hyperfine interactions were not significant at temperatures above 50 mK, the inclusion of the zero-field splitting interaction resulted in qualitative agreement with the data. We optimized this model using a nonlinear least square regression to find the best fit to the two experimental data sets with two independent fitting parameters. Measured data at 50 mK still show a significant reduction below the fitted model prediction. Conductance measurements and thermal relaxation times were used to characterize addenda heat capacity and entropy loss due to non-adiabatic effects, which were not found to be significant. Accordingly, cooling capacity reduction below 50 mK cannot be accounted for by these effects. CCA is in the same chemical family as Chrome-Potassium Alum (CPA) which used widely in adiabatic demagnetization refrigerators. Thus, this modelling work described here is applicable to CPA. New measurements are planned to understand if the remaining discrepancy between the model and data is a systematic effect or a more fundamental feature of the salt.

Geochemical ice-core constraints on the timing and climatic impact of Aniakchak II (1628BCE) and Thera (Minoan) volcanic eruptions.

Decades of research have focused on establishing the exact year and climatic impact of the Minoan eruption of Thera, Greece (c.1680 to 1500BCE). Ice cores offer key evidence to resolve this controversy, but attempts have been hampered by a lack of multivolcanic event synchronization between records. In this study, Antarctic and Greenland ice-core records are synchronized using a double bipolar sulfate marker, and calendar dates are assigned to each eruption revealed within the 'Thera period'. From this global-scale sequence of volcanic sulfate loading, we derive indications toward each eruption's latitude and potential to disrupt the climate system. Ultrafine sampling for sulfur isotopes and tephra conclusively demonstrate a colossal eruption of Alaska's Aniakchak II as the source of stratospheric sulfate in the now precisely dated1628 BCE ice layer. These findings end decades of speculation that Thera was responsible for the 1628BCE event, and place Aniakchak II (52 ± 17 Tg S) and an unknown volcano at 1654BCE (50 ± 13 Tg S) as two of the largest Northern Hemisphere sulfur injections in the last 4,000years. This opens possibilities to explore widespread climatic impacts for contemporary societies and, in pinpointing Aniakchak II, confirms that stratospheric sulfate can be globally distributed from eruptions outside the tropics. Dating options for Thera are reduced to a series of precisely dated, constrained stratospheric sulfur injection events at 1611BCE, 1561/1558/1555BCE, and c.1538BCE, which are all below 14 ± 5 Tg S, indicating a climatic forcing potential for Thera well below that of Tambora (1815CE).

Iron plays a role in sulfasalazine-induced ferroptosis with autophagic flux blockage in K7M2 osteosarcoma cells.

Osteosarcoma is the most common primary bone malignancy in children and young adults, with a very poor prognosis. It is of great importance to develop targeted therapeutic strategies for osteosarcoma. Sulfasalazine (SAS) is an FDA-approved drug for the treatment of Crohn's disease, rheumatoid arthritis, and inflammatory bowel disease. It acts as an inhibitor of cystine/glutamate system, which is important for cellular glutathione synthesis and maintenance of GPx4 activity. Nowadays, SAS has been repurposed as an antitumor drug for inducing ferroptosis in cancers. This study aimed to uncover the role of iron in SAS-induced ferroptotic cell death in K7M2 osteosarcoma cells. Herein, SAS led to an iron-dependent cell death mode in K7M2 cells, accompanied with decreased antioxidant defense and increased production of cytosolic and lipid reactive oxygen species. Results also showed that iron supplement with ferric ammonium citrate (FAC) or ferrous ammonium sulfate (FAS) exacerbated the declined cell viability of SAS-treated K7M2 cells, while in the case of iron depletion, it weakened such suppression. Furthermore, iron promoted SAS-induced alterations on cell cycle, cytoskeleton, mitochondria morphology and function, and redox system. Iron also induced the dysfunction of autophagic activity in SAS-treated K7M2 cells. In conclusion, our study uncovered the essential role of iron in SAS's effects on K7M2 cells and provided the potential combined therapy of inhibition on antioxidant defense and an increase in oxidative potential, which further disturbed the redox status in tumor cells.

Studying the Effect of Experimental Bases on the Growth Quality of Liquid Nutritional Media for Submerged Cultivation of Plague Microbe Vaccine Strain

The aim of the study was to investigate the effect of experimental bases on the growth qualities of liquid nutrient media at the stage of obtaining the biomass of plague microbe vaccine strain using submerged cultivation.Materials and methods. Yersinia pestis EV NIIEG vaccine strain was used in the work. The cultivation was carried out in a 5 L bioreactor with automatic stirrer control. We used 28 variants of nutrient media obtained through combining five types of bases and six growth stimulants. Nutrient media without the addition of growth-stimulating additives were used as controls. The following parameters were assessed in the yield biomass: the total number of microbial cells, pH, the percentage of viable microbial cells.Results and discussion. On experimental nutrient media, biomasses of the plague microbe vaccine strain have been produced using submerged cultivation. After evaluating bacterial suspensions by the main indicators, the quality of the obtained suspensions has been compared depending on the nutrient medium used. The most promising bases identified are pancreatic hydrolyzate of casein with dry enzymatic peptone and acid hydrolyzate of corn syrup, especially in combination with such growth stimulants as sodium sulfite, ferrous ammonium sulfate or ammonium molybdate.

Simultaneous oxidation of aromatic compounds using Sr‐doped lanthanum manganites as catalysts

Strontium-doped lanthanum manganites, La1-xSrxMnO3 (LSMO), are promising and affordable catalysts for oxidative degradation of volatile organic compounds. LSMO catalysts (x = 0, .1, .2, and .3) were prepared by the citrate-nitrate autocombustion (CNA) and coprecipitation synthesis. The phase composition was confirmed by X-ray diffraction and Rietveld refinement analysis, while the oxygen content was determined by Mohr's salt permanganate titration. Morphology and porosity of prepared catalysts was correlated to catalytic oxidation of benzene, toluene, ethylbenzene and o-xylene. It was observed that both synthesis methods yielded catalysts of similar average pore size diameter and specific surface area, but the pore size distribution differed: CNA-prepared catalysts had a multimodal pore size distribution, while the coprecipitated ones had a single maximum at 4 nm. Catalysts prepared by the CNA method have shown a higher catalytic activity in the temperature range 373–723 K, as the presence of Mn3+/Mn4+ mixed valences increased their reducibility.

Iron Bioavailability from Ferrous Ammonium Phosphate, Ferrous Sulfate, and Ferric Pyrophosphate in an Instant Milk Drink-A Stable Isotope Study in Children.

Ferrous ammonium phosphate (FAP) is an iron salt that has been developed for the fortification of food matrices sensitive to color and flavor changes. The objective of the study was to measure iron absorption from FAP in young children and compare it to a previous evaluation of FAP in young women. A double-blind randomized crossover study with two parallel arms was used to evaluate the iron absorption from FAP added to reconstituted milk powder in comparison to that from ferrous sulfate (FeSO4) and ferric pyrophosphate (FePP). Iron absorption was measured in 39 children aged 3- to 6-years-old using erythrocyte incorporation of stable Fe isotopes (57Fe, 58Fe). The geometric mean iron absorption in iron replete children from FAP, FeSO4 and FePP from milk was 8.3%, 7.6% and 2.1%, respectively. Iron absorption from FAP and FeSO4 fortified milk was not significantly different (p = 0.199); however, it was significantly higher than from FePP fortified milk (p < 0.001). Iron bioavailability from FAP and FePP relative to FeSO4 (relative bioavailability (RBV)) was 110% and 33%, respectively. The RBV of FAP (110%) in iron replete children was higher than previously reported RBV (71%) in mainly iron deficient women. The difference in iron status between the children and women in the respective studies may explain the different RBV values and is discussed.

Floor plants’ leaf shape and Phyllagathis rotundifolia’s soil organic matter in Kuala Keniam Trail, Pahang National Park

Abstract Kuala Keniam forest in the Pahang National Park is a part of the oldest and most complex ecosystem in the world with multispecies of plants and structures. Unfortunately, near to none information was documented on the geometrical aspects of leaves. Thus, this study aims to pre-document on the variety of shapes of leaves along the trail and classify them. Photographs of the plants and all site activities were taken and documented by using the digital single-lens reflex (DSLR) and smartphone-digital cameras. Secondly, this study also aims at understanding this one particular herbaceous plant, known as Phyllagathis rotundifolia (tapak sulaiman) which is commonly found along the trail, and traditionally used to relieve gastrointestinal problems and fever. The composition of the soil organic matter of the plant were collected for better understanding of the type of soil needed for mass-cultivation and medical purposes. The Walkley-Black (WB) titration method was used to analyse the soil, where the oxidation of organic matter by potassium dichromate (K2Cr2O7)-sulfuric acid mixture followed by back titration of the excessive dichromate by ferrous ammonium sulphate (Fe (NH4)2(SO4)2.6H2O) were monitored. Findings from the Kuala Keniam trails were documented and analysed. Thirty distinct-leaves have been identified and classified into 10-distinct leaf shape categories. Rich soil contents such as iron, carbon and phosphorous were also detected, thus creating Kuala Keniam as an excellent environment for the growth of beneficial shrubs and herbs

How Xylenol Orange and Ferrous Ammonium Sulphate Influence the Dosimetric Properties of PVA-GTA Fricke Gel Dosimeters: A Spectrophotometric Study.

The development of Fricke gel (FG) dosimeters based on poly(vinyl alcohol) (PVA) as the gelling agent and glutaraldehyde (GTA) as the cross-linker has enabled significant improvements in the dose response and the stability over time of spatial radiation dose distributions. However, a standard procedure for preparing FG in terms of reagent concentrations is still missing in the literature. This study aims to investigate, by means of spectrophotometric analyses, how the sensitivity to the radiation dose and the range of linearity of the dose–response curve of PVA-GTA-FG dosimeters loaded with xylenol orange sodium salt (XO) are influenced by ferrous ammonium sulphate (FAS) and XO concentrations. Moreover, the effect of different concentrations of such compounds on self-oxidation phenomena in the dosimeters was evaluated. PVA-GTA-FG dosimeters were prepared using XO concentrations in the range 0.04–0.80 mM and FAS in the range 0.05–5.00 mM. The optical absorbance properties and the dose response of FG were investigated in the interval 0.0–42.0 Gy. The results demonstrate that the amount of FAS and XO determines both the sensitivity to the absorbed dose and the interval of linearity of the dose–response curve. The study suggests that the best performances of FG dosimeters for spectrophotometric analyses can be obtained using 1.00–0.40 mM and 0.200–0.166 mM concentrations of FAS and XO, respectively.

Estimation of the Internal Dose Imparted by 18F-Fluorodeoxyglucose to Tissues by Using Fricke Dosimetry in a Phantom and Positron Emission Tomography.

Assessment of the radiation dose delivered to a tumor and different organs is a major issue when using radiolabelled compounds for diagnostic imaging or endoradiotherapy. The present article reports on a study to correlate the mean 18F-fluorodeoxyglucose (18F-FDG) activity in different tissues measured in a mouse model by positron emission tomography (PET) imaging, with the dose assessed in vitro by Fricke dosimetry. The dose-response relationship of the Fricke dosimeter and PET data was determined at different times after adding 18F-FDG (0-80 MBq) to a Fricke solution (1 mM ferrous ammonium sulfate in 0.4 M sulfuric acid). The total dose was assessed at 24 h (~13 half-lives of 18F-FDG). The number of coincident events produced in 3 mL of Fricke solution or 3 mL of deionized water that contained 60 MBq of 18F-FDG was measured using the Triumph/LabPET8TM preclinical PET/CT scanner. The total activity concentration measured by PET was correlated with the calculated dose from the Fricke dosimeter, at any exposure activity of 18F-FDG. The radiation dose measured with the Fricke dosimeter increased rapidly during the first 4 h after adding 18F-FDG and then gradually reached a plateau. Presence of non-radioactive-FDG did not alter the Fricke dosimetry. The characteristic responses of the dosimeter and PET imaging clearly exhibit linearity with injected activity of 18F-FDG. The dose (Gy) to time-integrated activity (MBq.h) relationship was measured, yielding a conversion factor of 0.064 ± 0.06 Gy/MBq.h in the present mouse model. This correlation provides an efficient alternative method to measure, three-dimensionally, the total and regional dose absorbed from 18F-radiotracers. The Fricke dosimeter can be used to calibrate a PET scanner, thus enabling the determination of dose from the measured radioactivity emitted by 18F-FDG in tissues. The method should be applicable to radiotracers with other positron-emitting radionuclides.

Flashover Voltage Prediction Models under Agricultural and Biological Contaminant Conditions on Insulators

The flashover performance of contaminated insulators highly depends on the type of pollutant and its present concentration. In this paper, important agricultural salts (NaCl, K2SO4, NaHCO3, CaSO4, KHCO3, MgSO4, NH4), 2Fe(SO4)2, and 6H2O (ferrous ammonium sulphate, dust, and urea) at different concentrations, and biological contaminants, such as algae and fungi, were taken as pollutants, and the AC flashover behavior of a porcelain-cap-and-pin-type insulator polluted with these two different pollutants was investigated. The experiment was carried out by a semi-natural method, wherein the insulator was first polluted artificially; thereafter, natural fog was applied to measure the wet flashover voltage. Test results indicated that the flashover voltages were affected by both soluble salts and non-soluble components deposited on the insulator surface. In the case of the thickly contaminated layers, non-soluble deposits greatly reduced the flashover voltage. Moreover, by using regression analysis, four empirical models based on different variables were developed. The empirical models developed in the present work represented a good degree of relation in predicting the flashover voltage of naturally contaminated insulators.

Histological, histochemical, ultrastructural and immunohistochemical identification and characterization of the neurosecretory cells of the adult rabbit's adrenal medulla.

The present investigation was conducted on the adrenal glands of 40 adult New Zealand rabbits of both sexes to characterize and identify the histological, histochemical, ultrastructural, and immunohistochemical features of the neurosecretory cells of the adrenal medulla. The obtained specimens of adrenal medulla were subjected to routine histological techniques and then stained with different histological stains, including general, non-specific, specific, and highly specific stains for neurosecretory cells, in addition to immunohistochemical reactions. The obtained results showed two types of adrenal medullary neurosecretory cells containing secretory granules (SGs) of different electron densities: adrenaline and noradrenaline (NA) secreting cells. These secretory granules showed a strong positive reaction to the Grimelius silver impregnation technique. Sections stained with Gomori's chrome alum haematoxylin stain, and the secretory granules showed a strong dark blackish-blue positive colour. The medullary cells showed typical chromaffin reactions when stained by H&E and Giemsa stains after formol dichromate 'Ortha's fluid' fixation. The noradrenaline secretory granules gave a strong positive Schmorl's test, while the adrenaline ones showed a moderate reaction. Immunohistochemically, the adrenal medullary cells were subjected to anti-chromogranin A (CHGA) antibody using the PAP technique, which gave positive reactions.

Recovery of nickel, cobalt and rare-earth elements from spent nickel–metal-hydride battery: Laboratory tests and pilot trials

The recycling of nickel, cobalt and rare earths from spent nickel–metal-hydride batteries was investigated. Nickel and cobalt were recovered as a nickel–cobalt mixed sulfide, which can be used as an intermediate raw material in existing nickel refineries. Rare earths were recovered as double sulfates, which can be recycled into industrial materials. In the recovery of rare earths, yttrium, a heavy rare earth, could be precipitated and recovered by co-precipitation with a light rare-earth double sulfate, which was considered impossible by the double-sulfate precipitation method because of high solubility of yttrium double sulfate. On the other hand, the coprecipitation behavior of yttrium was found to be unstable at the pilot scale because the stirring force was weaker than that in the laboratory experiments. In this study, the optimum conditions for leaching, double-sulfate precipitation, and sulfide precipitation reactions were determined in a laboratory test and the good performance was demonstrated in a pilot test. Based on the results, the estimated metal yields were 87% nickel, 90% cobalt, 54% yttrium, 99% lanthanum and 99% cerium. The nickel and cobalt impurities in the double sulfate that were recovered by this process were 0.04% and 0.005%, respectively, and the rare-earth impurities in the nickel–cobalt mixed sulfide were low at 0.049% yttrium, 0.007% lanthanum and 0.003% cerium. This process combined with a precipitation method showed a high separation performance.

Mineralogical and Chemical Changes after Reduction Roasting of Xinjiang Iron Ore, China

The mineralogical and chemical changes in Chinese Xinjiang iron ore containing impurities, lead, and zinc as a result of reduction roasting were studied via chemical analysis, optical microscopy, X-ray fluorescence (XRF), electron probe microanalysis (EPMA), and energy-dispersive spectroscopy (EDS). Analysis showed that hematite was the main iron-bearing mineral, with small amounts of magnetite and iron silicate; lead impurities were mainly lead oxide and lead–iron alum, while zinc oxide was the main zinc impurity. X-ray fluorescence analysis for raw samples indicated the presence of quartz, hematite, magnetite, chlorite, calcite, and dolomite. The results of the analysis of roasted samples showed an increase in hematite at temperatures of 750 °C and 950 °C, while the elemental iron increased at a temperature of 1200 °C, along with the conversion of galena to lead oxide and sphalerite to zinc oxide, with a stable quartz ratio. The chemical analysis of the raw sample showed that the TFe grade of the sample was 47.04%, while the contents of harmful Pb and Zn impurities were 0.39% and 0.30%, respectively, both of which exceed the index (less than 0.10%) required by the iron industry for raw materials. The content of harmful sulfur impurities was also high, at 1.19%, which needs to be eliminated or reduced. The results of EPMA and EDS analysis of pre-roasting raw samples showed that chemical compositions vary in different locations in the hematite, magnetite, sphalerite, and galena micro-zones. It has also been observed that quartz is mostly diffused with magnetite and hematite, and sulfur appears in small quantities in most regions. The analysis after roasting showed that the percentages of lead, zinc, and sulfur impurities decreased by a large rate. It is clear that the roasting process plays a major role in removing impurities such as sulfur, which appears in a small percentage after the roasting process, and also helps in oxidizing the impurities of lead and zinc, which helps in removing them.

Study of the natural mineral sorbents’ absorption properties of the Ural region (Russia)

The article is devoted to the study of the sorption properties of natural mineral sorbents from deposits located in the Ural (Sverdlovsk, Kurgan, Chelyabinsk regions). For the experiments, the following natural sorbents were used: bentonite clays with an admixture of carbonate inclusion; flasks - dense, slightly porous rocks consisting of the smallest particles of biogenic silica; diatomite; glauconites- layered low-temperature ferruginous micas; calcined vermiculite. The absorption capacity in relation to heavy metals: copper, zinc, lead, cadmium, nickel, chromium, arsenic has been investigated. The are no significant differences in the completeness of sorption between the studied sorbents, all of them can be successfully used under certain conditions for ecological and geochemical recultivation of soils contaminated with HMs. Separately, the influence of sorbents on the copper and chromium absorption as the largest soil pollutants in the Urals was considered. Experiments have shown that copper in the form of a bivalent cation is well sorbed by all sorbents, while chromium in the form of a complex anion (in a hexavalent form) is practically not sorbed. To ensure a proper chromium sorption effect, it was decided to preliminary transfer it into a trivalent cationic form by a reducing agent, which was ferrous ammonium sulfate - FeSO4·(NH4)2·SO4·6H2O. The reduction of chromium to a trivalent cation increases the sorption completeness to 94-99%.

Structural transformation of Na2Mn2(SO4)3 alluaudite into orthorhombic Li2Mn2(SO4)3 induced after lithium intercalation

Double sulfate salts of sodium and manganese, Na2Mn2(SO4)3, with an alluaudite-type of structure has been shown to intercalate Li+ ions reversibly, but the mechanism is still unclear. This study aims to examine the structure transformation of the alluaudite sodium manganese sulfate Na2Mn2(SO4)3 after Li+ intercalation by means of ex-situ transmission electron microscopy. We demonstrate that lithium intercalation into alluaudite Na2Mn2(SO4)3 proceeds at a nano-scale and leads to a formation of orthorhombic phase Li2Mn2(SO4)3. Although the alluaudite and orthorhombic structures possess common Mn2O10 entities, they are completely different. Because of the nano-structure, in-situ generated phase Li2Mn2(SO4)3 displays better capacity in comparison with the phase obtained before the electrochemical experiment. The orthorhombic Li2Mn2(SO4)3 is obtained by freeze-drying method, followed by thermal treatment at 500 °C. The revised electrochemical property shows that orthorhombic Li2Mn2(SO4)3 is able to intercalate reversible at least 1 mol of Li only in the case when electrolyte based on ionic liquid is used.

Labile iron, ROS, and cell death are prominently induced by haemin, but not by non-transferrin-bound iron

BackgroundIn transfusion-related iron overload, haem-derived iron accumulation in monocytes/macrophages is the initial event. When iron loading exceeds the ferritin storage capacity, iron is released into the plasma. When iron loading exceeds transferrin binding capacity, labile, non-transferrin-bound iron (NTBI) appears and causes organ injury. Haemin-induced cell death has already been investigated; however, whether NTBI induces cell death in monocytes/macrophages remains unclear. Material and MethodsHuman monocytic THP-1 cells were treated with haemin or NTBI, particularly ferric ammonium citrate (FAC) or ferrous ammonium sulfate (FAS). The intracellular labile iron pool (LIP) was measured using an iron-sensitive fluorescent probe. Ferritin expression was measured by western blotting. ResultsLIP was elevated after haemin treatment but not after FAC or FAS treatment. Reactive oxygen species (ROS) generation and cell death induction were remarkable after haemin treatment but not after FAC or FAS treatment. Ferritin expression was not different between the FAC and haemin treatments. The combination of an iron chelator and a ferroptosis inhibitor significantly augmented the suppression of haemin cytotoxicity (p = 0.011). DiscussionThe difference in LIP suggests the different iron traffic mechanisms for haem-derived iron and NTBI. The Combination of iron chelators and antioxidants is beneficial for iron overload therapy.

Fabrication of ferrous tungstate with enhanced sonocatalytic performance for meloxicam removal

The composites ferrous tungstate (FeWO4) were fabricated as the sonocatalyst for degradation of meloxicam (MEL) in water. The composites are prepared carefully via hydrothermal reaction of sodium tungstate dehydrate and ferrous ammonium sulfate hexahydrate. The morphology of FeWO4 were controlled successfully, by adjusting the acidity of the reaction solution (pH = 5, 6, 7, 8, 9). Multiple characterization results revealed that the obtained FeWO4 shared the similar nano-microspheres structure, but with different BET surface area and energy gap. The sonocatalytic experiments showed that FeWO4 nanomaterials with various synthetic pH values had different sonocatalytic performance on degradation of meloxicam (MEL), and FeWO4 synthesized at pH 6 reaches maximum of 73.5% on degradation of MEL. This phenomenon was not only due to the moderate BET surface area (31.18 m2/g), moderate pore size distribution (10–30 nm) and moderate energy gap (1.73 eV) of FeWO4 nano-microspheres, ·OH and holes also played a key role in the removal of MEL. The obtained catalyst was proved to be stable enough after four cycles. Our study demonstrates a novel finding, not reported previously, that FeWO4 could be utilized as a promising sonocatalyst to degrade MEL by ultrasound-driven.