Iron System Research Articles

Molecular dynamics investigation of structural, thermal, and dynamic properties of maghemite through thermal cycling.

We analyzed the thermal, structural, and dynamic properties of maghemite using classical molecular dynamics, focusing on bulk and nanoparticle systems. We explored their behavior when heated to high temperatures (above the melting point) and during cooling, as well as under thermal cycles ending at intermediate temperatures. Our findings show that in the bulk system, both the tetrahedral and octahedral iron sub-lattices undergo a phase transition prior to melting. Cooling the system from above this transition, or from above the melting point, leads to the formation of different metastable maghemite structures. In contrast, this sub-lattice transition is absent in nanoparticles, where melting occurs through an interface-mediated process. At temperatures just above the transition, nanoparticles adopt an ellipsoidal shape, which is retained during cooling. In addition, the specific heat of both bulk and nanoparticle systems at temperatures above the Debye temperature is evaluated and compared with the available experimental data. Overall, our results highlight the complex thermal behavior of maghemite across a range of temperatures, which remains insufficiently explored experimentally. Further experimental investigations could also provide valuable feedback for model refinements.

The efficacy of IV iron in anemic heart failure patients: a systemic review and meta-analysis of randomised controlled trials

Abstract Introduction Iron deficiency in the context of heart failure is a multifaceted concern, where the intricate interplay between diminished iron stores, impaired absorption mechanisms, and reduced recycled iron in the reticuloendothelial system adds a layer of complexity to patient management. Initial attempts to address this issue with oral iron treatments have been questioned due to its poor absorption. Intravenous iron therapy is now preferred, as it has been shown to reduce heart failure hospitalisations and cardiovascular mortality. However, there is a lack of randomised studies specifically focused on heart failure patients, highlighting the need for more targeted investigations. Purpose The aim of this review is to provide reliable evidence from published randomised controlled trials (RCTs) regarding the beneficial effect of IV iron in heart failure patients. Methods We systematically searched PubMed, Web of Science, Scopus, and Cochrane Central, and EMBASE from inception until December 2023. We included randomised controlled trials (RCTs) comparing the effect of IV iron in heart failure patients versus placebo. The primary outcomes were 6MWT mean change, ferritin concentration mean change, transferrin saturation mean change and worsening heart failure. All data were pooled as either Mean difference in the random effect model with the corresponding SD or pooled as RR and 95% CI for dichotomous data. Results Twelve RCTs involving 6800 patients were included in the analysis. The overall effect on the measured primary outcomes was in favour of IV iron in terms of 6MWT mean change (MD= 34.45, 95% CI [ 29.58 to 39.31], P=<0.0001), ferritin concentration mean change (MD= 219.18, 95% CI [ 208.7 to 229.66], P=<0.0001), transferrin saturation mean change (MD= 9.77, 95% CI [ 8.14 to 1.39], P=<0.0001) and worsening heart failure (RR= 0.46, 95% CI [ 0.31 to 0.69], P=0.002). Conclusion The introduction of the IV iron therapy to heart failure patients showed a beneficial effect in terms of the measured haematological and cardiovascular metrics, which include 6MW test mean change, ferritin concentration mean change, and worsening heart failure.6MWT mean changeFerritin mean change

Degradation kinetics, influencing factors, and mechanisms of polycyclic aromatic hydrocarbons in a Fe3O4-nZVI Fenton-like system

To improve the catalytic performance of nano zero-valent iron (nZVI) in a Fenton-like system, Fe3O4 supported nZVI (Fe3O4-nZVI) was produced by the liquid-phase reduction method and co-precipitation method, then characterized by SEM, EDS, XRD, XPS, and VSM. Fe3O4-nZVI was used as the catalyst in a Fenton-like system to degrade polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap), phenanthrene (Phe), and pyrene (Pyr) in simulated wastewater. The results showed that under the optimization conditions, which were 25 ℃, 0.6 g/L of Fe3O4-nZVI dosage, 3 of the pH in the reaction system, and 10–15 mmol/L of the concentration of H2O2, the sequence of degradation efficiency in this system was Phe (99.76 %)>Pyr (99.71 %)>Nap (98.01 %). The reused experiments on Fe3O4-nZVI showed that the degradation efficiency for PAHs remained above 87 % after 4 reuses of Fe3O4-nZVI. These results indicated that nanoscale magnetic composites of Fe3O4-nZVI had excellent reactivity, stability, and reuse performance. The fitting parameters of kinetics showed that the degradation of PAHs in the Fenton-like system with the Fe3O4-nZVI catalyst fitted well with the Behnajady-Modirshahla-Ghanbery kinetic model. The radial quenching experiment proved that·OH was the dominant free radical for the degradation of PAHs in the Fe3O4-nZVI Fenton-like system. Based on the degradation products of PAHs and the related literature, the possible degradation paths of the three PAHs in the Fe3O4-nZVI Fenton-like system were inferred. The above results could provide a reference and basis for the treatment of wastewater containing PAHs by Fe3O4-nZVI Fenton-like technology.

Separation and utilization of iron, cerium, and other rare earth elements from rare earth waste by chlorination

Due to the lack of effective screening systems in the rare earth waste recycling industry, the composition of rare earth elements in rare earth waste is complex and difficult to separate. In response to such problems, by studying the reaction behavior between various elements in rare earth waste and cobalt chloride, we propose a process path for the separation and recovery of iron, cerium and other rare earth elements using cobalt chloride roasting. The experiments on simulated wastes show that the leaching rates of the Nd, Sm, Gd, Pr can reach 98.31%, 94.5%, 93.87% and 72.05% under the optimal process conditions, respectively. Ce and iron remain in the leaching residue in the form of CeO2 and CoFe2O4, respectively. And through a simple magnetic separation process, CeO2 and CoFe2O4 can be enriched in non-magnetic leaching residue and magnetic leaching residue, respectively. The cerium content in the leaching residue composed of cobalt ferrite is only 1.95%. Therefore, this method is beneficial to the separation and high-value utilization of iron, cerium, and other rare earth elements in the waste system. The research results can provide theoretical reference for the low-cost and high-value recovery of rare earth secondary resources.

High Concentration of Iron Ions Contributes to Ferroptosis-Mediated Testis Injury.

In order to explore the effect of excessive iron supplementation on ferroptosis in mouse testes, Kunming mice received injections of varying concentrations of iron. The organ weight, sperm density, and malformation rate were measured. Observations of pathological and ultrastructural alterations in spermatogenic tubules were conducted using haematoxylin eosin (HE) staining and transmission electron microscopy(TEM). Transcript levels of related genes and serum biochemical indicators were measured in mouse testicular tissue. The results showed that higher iron concentration inhibited the growth of mice; reduced the organ coefficients of the testis, heart, and liver; and increased the rate of sperm malformation and mortality. Supplementation with high levels of iron ions can adversely affect the male reproductive system by reducing sperm count, damaging the structure of the seminiferous tubules and causing sperm cell abnormalities. In addition, the iron levels also affected the immune response and blood coagulation ability by affecting the red blood cells, white blood cells and platelets. The results showed that iron ions can affect mouse testicular tissue and induce ferroptosis by altering the expression of ferroptosis-related genes. However, the degree of effect was different for the different concentrations of iron ions. The study also revealed the potential role of deferoxamine in inhibiting the occurrence of ferroptosis. Nevertheless, the damage caused to the testis by deferoxamine supplementation suggests the need for further research in this direction. This study provides reference for reproductive toxicity induced by environmental iron exposure and clarifies the mechanism of reproductive toxicity caused by iron overload and the important role of iron in the male reproductive system.

Observations and simulations for separation mechanism of vanadium and chromium: Progressive study based on oxides, spinels and vanadium-chromium slag

In this study, V2O3-CaO-Cr2O3 oxides system, Fe2VO4-CaO-FeCr2O4 spinels system and V-Cr slag-CaO system were established progressively to investigate the separation effect of vanadium and chromium components in vanadium-chromium slag (V-Cr slag). Then, the separation mechanism was proposed by XRD, SEM and leaching experiments. The results show that the reaction ability of vanadium with calcium is far stronger than that of chromium. In oxides and spinels systems, as CaO increases, CaV2O6, Ca2V2O7, and Ca3V2O8 are generated sequentially. In V-Cr slag-CaO system, additive CaO, along with manganese, magnesium and iron components in V-Cr slag reacts with vanadium, resulting in the complex composition of vanadate. As to chromium component, Cr2O3 in oxides system will be converted into CaCrO4 as n(CaO)/n(V2O3) is higher than 2. Iron in the spinels system reacts with chromium and form solid solution (FexCr1-x)2O3, resulting in less chromium reacting with calcium to produce CaCrO4. In V-Cr slag-CaO system, SiO2 generated by the decomposition of silicate phase combines with part of calcium expected to react with chromium, making CaCrO4 generation more difficult, promoting the separation of vanadium and chromium further. Consequently, during H2SO4 leaching, chromium leaching ratios are 98.75%, 45.77% and 5.91%, respectively, in oxides, spinels and V-Cr slag system when n(CaO)/n(V2O3) is 5. And when n(CaO)/n(V2O3) is 2, more than 90% of vanadium can be leached, however, the leaching ratios of chromium are 0.22%, 0.17% and 0.094% in these three systems. Furthermore, the variation regularities of chromium leaching ratios with CaO amount are described by regression equations. These findings would provide the theoretical support for the calcification roasting process with V-Cr slag.

Perceptions and experiences of intravenous iron treatment for anaemia in pregnancy in Malawi: a formative qualitative study

Background The study objective was to explore opinions, identify experiences, and describe perspectives on the acceptability of intravenous (IV) iron to treat anaemia in pregnancy and identify potential barriers and facilitators of introducing IV iron in the Malawian healthcare system. Methods We conducted 15 in-depth interviews and two focus group discussions with pregnant women, and seven in-depth interviews with health workers at a community-based health centre in Blantyre and a tertiary hospital in Zomba. Results Most women who used IV iron treatment during the second trimester of pregnancy reported feeling better and stronger after receiving the intervention. Women perceived that IV iron treatment worked faster than oral iron tablets and increased their haemoglobin count. However, cultural beliefs that IV iron treatment will cause miscarriage and the perception that study procedures involved Satanism and vampirism practices were barriers to acceptability. Health workers found IV iron treatment easy to administer because it is a single-dose treatment, simultaneously reducing the burden for pregnant women taking daily oral iron tablets. However, health workers expressed concerns about the costs and the need to train health workers before the large-scale implementation and integration of IV iron treatment into Malawi’s routine care. Conclusions Despite the perceived concerns and challenges experienced in participating in the first IV iron infusion trial in Malawi, participants’ reflections suggest that IV iron infusion is acceptable for treating iron-deficiency anaemia in pregnancy. Participant advocate groups can offer a peer-to-peer education approach to sensitize and engage community members on the benefits of treatment and dispel concerns when the country contemplates integrating IV iron infusion for treating anaemia in pregnancy in Malawi.

Evaluation of a Novel High-Efficiency SHS-EAH Multi-Stage DG-ADP Process for Cleaner Production of High-Quality Ferrovanadium Alloy

A novel high-efficiency industrialized clean production technology based on multi-stage gradient batching and smelting was proposed for the production of high-quality ferrovanadium. The thermodynamic mechanism of aluminothermic reduction equilibrium, alloy settlement and raw material impurity distribution were confirmed, and a multi-stage double-gradient aluminum addition pattern (DG-ADP), the highly efficient separation of molten slag and alloy, and typical impurity control standards of raw materials were achieved on the basis of a self-propagating high-temperature synthesis with an electric auxiliary heating (SHS-EAH) process. The reduction efficiency, separation efficiency and the comprehensive utilization rate of the secondary resources were significantly improved, as the whole total vanadium (T.V) content in the industrially produced residue slag reduced from 2.34 wt.% to 0.60 wt.%, while the corresponding smelting yield increased from 93.7 wt.% to 98.7 wt.% and the aluminum consumption decreased from 510 kg·t−1 to 400 kg·t−1. The multi-stage DG-ADP process enabled the internal circulation of vanadium-bearing materials in the ferrovanadium smelting system, as well as the external circulation of iron and residue slag in the same system, and finally achieved the zero discharge of solid and liquid waste from the ferrovanadium production line, which provides a brand-new perspective for the cleaner production of ferrovanadium alloy.

A case of atypical IgA paraprotein interference on multiple chemistry assays: How to deal with it.

This case report discusses how paraproteins interfere with multiple chemistry analyses and protocols to overcome such obstacles. A serum specimen containing two monoclonal IgA (llight chain) paraproteins is subjected to a battery of tests on three wet chemistry platforms - AU5800, Cobas Pure, and Alinityci; the results were compared with those on a Vitros 350/ ECiQ dry chemistry platform. Paraprotein interference was found to affect the bilirubins, inorganic phosphate, and iron, whose repeat runs were also found to be irreproducible. Dilution with normal saline also failed to produce a satisfactory effect. Deproteinization by polyethylene glycol and dilution of the specimen with a normal serum specimen were observed to produce desirable results. Interference by IgA paraprotein on measurement of the bilirubin, phosphate, and iron in the wet chemistry system can be mitigated either by deproteinization or by dilution with normal serum.

Impact of iron supplementation on media bed aquaponic system: Focusing on growth performance, fatty acid composition and health status of juvenile mirror carp (Cyprinus carpio var. specularis), production of lettuce (Lactuca sativa var. ramosa Hort), water quality and nitrogen utilization rate

To evaluate the effects of iron supplementation on the growth performance, body composition and health status of mirror carp (Cyprinus carpio var. specularis) (10.34 ± 1.56 g), production of lettuce (Lactuca sativa var. ramosa Hort), and nitrogen utilization efficiency in media bed aquaponic system, a 60-day experiment was conducted. During the experiment, 0 (C), 1, 2, 3 and 4 mg/L iron chelate (ferrous glycinate) was added to fish tank of each system every 20 days. The results indicated as following: (1) Regarding the growth performance of mirror carp, the 1 mg/L group showed the highest weight gain (WG) and the lowest feed conversion ratio (FCR) when compared to the C group and the 4 mg/L group (P < 0.05). (2) In terms of body composition of mirror carp, the 1 mg/L group exhibited a significant increase in crude fat and iron content in the muscle (P < 0.05), and the ∑n-3 LCPUFA (C20:5n-3, EPA; C22:6n-3, DHA) was significantly higher in this group compared to the other groups (P < 0.05). (3) Regarding the health status of mirror carp, the 1 mg/L group had the highest liver catalase (CAT) activity, and the level of superoxide dismutase (SOD) activity was significantly higher than in the C, 3 mg/L, and 4 mg/L groups (P < 0.05). Liver malondialdehyde (MDA) content of mirror carp was significantly lower in 1 mg/L group compare to other groups (P < 0.05). (4) Concerning lettuce growth, the yield increased with rising iron content, and the group with 2 mg/L exhibited the highest chlorophyll content (P < 0.05). (5) Nitrogen utilization results showed that the 2 mg/L chelated iron group had the highest nitrogen utilization rate of 33.95%, while the C group had the lowest nitrogen utilization rate of 28.61%. Additionally, iron supplementation did not have a negative impact on the water quality of the aquaponic system. In summary, under the conditions of this study, adding 1 mg/L of chelate iron every 20 days in the aquaponic system is beneficial to the growth, body composition and health status of the mirror carp, the lettuce in the 2 mg/L group had better growth and yield. It is recommended to add 1–2 mg/L glycine chelated iron in the media bed aquaponic system every 20 days to promote the growth of fish and vegetables and improve the nitrogen utilization efficiency of the system.

Magnetic carbon formation via in-situ CO2 capture and electrolysis in a molten carbonate system

CO2 gas has been used as a feedstock to demonstrate the effectiveness of direct CO2 electrolysis for the generation of value-added carbon products from problematic greenhouse gas. Iron-based materials act as low-cost catalysts in the synthesis of graphitic carbon in several electrochemical applications for conversions of CO2 to carbonaceous substances, however limited attention has been given to the influence of this abundant material on deposition outcomes. It was therefore the aim here to observe cathodic behaviour of iron in a high-temperature electrolysis system and compare its performance with an alloyed iron (stainless steel) cathode. In this work, a eutectic ternary (Li, Na, K)2CO3 electrolyte at a mild temperature of 600 °C has been used as the reduction process medium while capturing CO2 to regenerate carbonate. The electrolytic carbon products have been extensively characterized by different tests to determine physical and chemical properties of products formed. The impact of temperature and thermal cycling of electrolytes on the electrodeposition process have also been studied. Carbon with magnetic properties has been synthesized using a bulk iron cathode at a temperature of 600 °C, while employing alloyed iron inhibited the formation of magnetic carbon in similar experimental conditions. The mechanism of magnetic carbon formation on a bulk iron cathode has been explained to result from in-situ iron oxide formation on the surface of the cathode which is subsequently reduced to iron metal under reduction potential and subsequent inclusion of iron with the carbon products. This study provides a single-step process for synthesizing valuable magnetic carbon which not only used CO2 as the feedstock during its formation but has multiple value-added material applications.

Prevalence of anaemia, iron, and vitamin deficiencies in the health system in the Republic of Ireland: a retrospective cohort study.

Anaemia is a common but treatable condition that predicts adverse clinical outcomes. However, standards of anaemia management vary considerably. To estimate the prevalence of anaemia and extent of screening for common underlying causes in the healthcare system in the Republic of Ireland. We conducted a retrospective cohort study of 112 181 adult patients, aged ≥18 years, who had a full blood count performed in 2013, using data from the National Kidney Disease Surveillance System. The prevalence of anaemia was determined across demographic and clinical subgroups, according to World Health Organization (WHO) definitions. The proportion screened for iron, vitamin B12, and folate deficiency was determined within a 3-month follow-up period and the corresponding prevalence for each deficiency determined. The overall prevalence of anaemia was 12.0% (95% confidence interval [CI] = 11.8% to 12.2%) and was higher in women than men (13.2% versus 10.5%, P<0.001). Anaemia increased with advancing age (33.4% for those aged >75 years) and worsening kidney function (8.2%, 10.9%, 33.2%, and 63.8% for each estimated glomerular filtration rate [eGFR] categories >90, 60-89, 30-59 and <30 ml/min/1.73 m², respectively, P<0.001). After 3-months' follow-up, the proportion screened for iron deficiency was 11.2% based on transferrin saturation and 33.7% using serum ferritin. Screening for folate and B12 deficiency was 17.6% and 19.8%, respectively. Among screened patients, the prevalence of iron deficiency, B12, and folate deficiency was 37.0%, 6.3%, and 5.8%, respectively. The burden of anaemia in the healthcare system is substantial especially for older patients and those with advanced kidney disease. Low screening rates for iron, B12, and folate deficiency are common and warrant quality improvement initiatives.

Evaluation of Lead and Iron Content in Different Stages of Water Treatment Facilities within Otuoke and Yenagoa Metropolis, Bayelsa State, Nigeria

The mechanism of keeping water safe by improving its quality makes it easily accessible for community health. The objective of this work was to evaluate the levels of lead and Iron in the domestic water supply system at Ekeki Housing Estate Yenegoa local government and Otuoke community in Ogbia local government in Bayelsa State, Nigeria. AAS version 5.0 Model was used to analyze Iron and Lead after acid digestion. Results obtained were compared with WHO standard, and statistically inferences were drawn using ANOVA and Spearman correlation matrix. All water sampled presented values of lead between (0.02-0.64) mg/L expect for point I3 and I4 which conformed to 0.01mg/L, while Iron values ranged from (0.01-5.3) mg/L. Most of the results obtained exceeded the WHO standard of 0.01 mg/L for lead and 0.03mg/L respectively. The research findings had shown that most treatment processes adopted were not suitable for treatment of the contaminants, hence the need to review treatment processes, distribution and monitoring of the source.

Selective formation of high-valent iron in Fenton-like system for emerging contaminants degradation under near-neutral and high-salt conditions

In view of the near-neutral and high-salt conditions, the Fenton technology with hydroxyl radicals (HO•) as the main reactive species is difficult to satisfy the removal of trace emerging contaminants (ECs) in pharmaceutical sewage. Here, a layered double hydroxide FeZn-LDH was prepared, and the selective formation of ≡Fe(IV)=O in Fenton-like system was accomplished by the chemical environment regulation of the iron sites and the pH control of the microregion. The introduced zinc can increase the length of Fe-O bond in the FeZn-LDH shell layer by 0.22 Å compared to that in Fe2O3, which was conducive to the oxygen transfer process between ≡Fe(III) and H2O2, resulting in the ≡Fe(IV)=O formation. Besides, the amphoteric hydroxide Zn(OH)2 can regulate the pH of the FeZn-LDH surface microregion, maintaining reaction pH at around 6.5–7.5, which could avoid the quenching of ≡Fe(IV)=O by H+. On the other hand, owing to the anti-interference of ≡Fe(IV)=O and the near-zero Zeta potential on the FeZn-LDH surface, the trace ECs can also be effectively degraded under high-salt conditions. Consequently, the process of ≡Fe(IV)=O generation in FeZn-LDH system can satisfy the efficient removal of ECs under near-neutral and high-salt conditions.

Immobilization of phosphorus in water-sediment system by iron-modified attapulgite, calcite, bentonite and dolomite under feed input condition: Efficiency, mechanism, application mode effect and response of microbial communities and iron mobilization

Four kinds of iron-based materials, i.e., iron-modified attapulgite, calcite, bentonite and dolomite (abbreviated as Fe-ATP, Fe-CA, Fe-BT and Fe-DOL, respectively) were prepared and used to immobilize the phosphorus in the system of overlying water (O-water) and sediment under the feed input condition, and their immobilization efficiencies and mechanisms were investigated. The influence of application mode on the immobilization of phosphorus in the water-sediment system by Fe-ATP, Fe-CA, Fe-BT and Fe-DOL was researched. The effects of Fe-ATP, Fe-CA, Fe-BT and Fe-DOL on the concentration of labile iron in the water-sediment system and the microbial communities in sediment were also studied. The results showed that the Fe-ATP, Fe-CA, Fe-BT and Fe-DOL addition all can effectively immobilize the soluble reactive phosphorus (SRP), dissolved total phosphorus (DTP) and diffusive gradients in thin-films (DGT)-labile phosphorus in O-water under the feed input condition, and also had the ability to inactivate the DGT-labile phosphorus in the top sediment. Although the change in the application mode from the one-time addition to the multiple addition reduced the inactivation efficiencies of SRP and DTP in O-water in the early period of application, it increased the immobilization efficiencies in the later period of application. Although Fe-ATP, Fe-CA, Fe-BT and Fe-DOL had a certain releasing risk of iron into the pore water, they had negligible risk of iron release into O-water. The addition of Fe-ATP, Fe-CA, Fe-BT or Fe-DOL reshaped the sediment bacterial community structure and can affect the microorganism-driven phosphorus cycle in the sediment. Results of this work suggest that Fe-ATP, Fe-CA, Fe-BT and Fe-DOL are promising phosphorus-inactivation materials to immobilize the phosphorus in the water-sediment system under the feed input condition.

Sulfidated nanoscale zero valent iron for in situ immobilization of hexavalent chromium in soil and response of indigenous microbes

This study aimed to investigate the immobilization efficiency of sulfidated nanoscale zero valent iron on Cr(VI) in soil. Reactions between sulfidated nanoscale zero valent iron and Cr(VI) in soil system and effects of sulfidated nanoscale zero valent iron on microbes had been demonstrated. Solid characterization results confirmed the incorporation of sulfur into nanoscale zero valent iron. Furthermore, the main oxidation products of iron after the reactions were magnetite, goethite and lepidocrocite. Fe–Cr complexes indicated that Cr(VI) was reduced to Cr(III). The results of 16 S rRNA gene analysis indicated that the sulfidated nanoscale zero valent iron had a limited bactericidal effect but further stimulated the sulfite reductase gene population, representing its positive effect for the soil remediation. The study showed that some microflora such as Protobacteria were promoted, while others community such as Firmicutes, were depressed. Furthermore, Cr mainly converted from a high toxic state such as exchangeable (EX) to less bioavailable state such as iron-manganese oxides bound (OX) and organic matter-bound (OM), thus reducing the toxicity of Cr when sulfidated nanoscale zero valent iron was added. High immobilization efficiency of the Cr(VI) compared to nanoscale zero valent iron indicated an improvement on selectivity and reactivity after sulfidation. Overall, sulfidated nanoscale zero valent iron was promising for the immobilization of Cr(VI) immobilization soil.

Minerals and their role in the optimal functioning of the immune system – literature review

An adequate supply of minerals in the diet is crucial for the proper functioning of the immune system. This applies to both the mechanisms of innate and adaptive immunity, and in particular, the pro- and anti-inflammatory balance of the body. For most people, a balanced diet is sufficient to provide the body with adequate amounts of minerals. However, certain groups are particularly at risk of deficiencies in these nutrients. These include people who perform frequent and intense sports training when the body does not have an opportunity to regenerate properly. The aim of this paper was to discuss the role of minerals in the suitable functioning of the immune system. The following review of the latest literature focuses on the role of magnesium, zinc, iron and selenium as the components of greatest importance in immunology. The effects of a deficiency of these minerals and their impact on the maturation and function of immunocompetent cells, antibody production, cytokine production and immune pathways are discussed. The review was based on the available data collected in the PubMed database and in the Google Scholar search engine using the keywords: “the role of magnesium in the immune system”, “the role of zinc in the immune system”, “the role of iron in the immune system”, the role of selenium in the immune system”, “mineral deficiencies in athletes”, “impact of intense physical exercise on the immune system”.

Novel Fe‐Based Amorphous Brazing Foils in the Quinary System Fe–Ni–Cr–Si–B

Amorphous brazing foils are increasingly used on a wide variety of component geometries because of their flexibility and the resulting ease of application. Due to the recent rapid rise in Ni prices, there is an enormous need for research into the substitution of nickel with iron within conventionally used nickel‐based amorphous brazing foils. To avoid time‐consuming series of experiments, newly developed thermodynamic databases will be used to predict alloy compositions with a high glass forming ability. Foils should be produced with the melt‐spin process and characterized with differential scanning calorimetry and secondary electron microscopy. Novel iron‐based brazing foils with different compositions are successfully produced in the alloying system iron–nickel–chromium–silicon–boron. The characterization of these foils indicates the presence of a partly amorphous or nanocrystalline structure. The novel iron‐based brazing foils are characterized by a simple and cost‐efficient alloying concept. Furthermore, newly developed thermodynamic databases in the iron–nickel–chromium–silicon–boron system are validated by the successful production of these foils. The prediction of further iron‐based amorphous foils with the aid of thermodynamic calculations can thus be made possible.

Insights of Colorimetric Estimation of Phytic Acid in Rice Grain

Phytic acid present in rice grain is an anti-nutrient that hinders the absorption of iron (Fe) and zinc (Zn) ions in the human digestive system. Estimation of phytic acid is a part of the biofortification studies targeted to enhance micronutrient content in the rice grain. Among the various methods of phytic acid estimation, colorimetric method is highly amenable to most of the laboratories due to its simple requirements. Wade reagent has been widely used in phytic acid estimation in various crops. However, details like the range of phytic acid concentrations required for standard graph preparation and maximum limits of detection were not clearly mentioned and the volume of Wade reagent differed. Hence, the objective of this study is to identify the range of phytic acid concentrations that is suitable to develop phytic acid standard graph followed by the determination of the maximum limit of Wade reagent volume. The results of this study will be useful in the future studies to understand the inherent details like the volume of Wade reagent, volume of biological extract, optimum volume as well as concentration optimum for standard graph preparation and the factor for calculating phytate-P from phytic acid.

Biochar regulates biogeochemical cycling of iron and chromium in a soil-rice system by stimulating Geobacter and Clostridium

In soil-rice systems, microbial reduction of iron (Fe) has been recognized as a crucial biogeochemical process that regulates Fe and chromium (Cr) translocation; however, the underlying processes are unknown. To investigate the impacts of biochar on the biochemical cycling of Fe and Cr and their toxicity to rice, maize straw biochar was applied at 1% (weight/weight) to a paddy soil spiked with 300 mg kg-1 Cr under two phosphorus (P) levels (0 or 90 mg kg-1) in a pot experiment. The key microbial groups affecting Fe dissimilatory reduction and their environmental drivers were explored. Biochar inhibited root Cr uptake by 36%, owing to the promoted iron plaque (IP) formation on the rice root surface. Correlation analysis showed that Fe concentration in pore water was strongly linked to the abundances of Geobacter (r = 0.81–0.94, P < 0.05) and Clostridium (r = 0.83–0.95, P < 0.05), indicating that Geobacter and Clostridium played essential roles in Fe reduction. Redundancy analysis showed that labile carbon and pore water P concentrations were the key determinants influencing Fe-reducing bacterial abundances, accounting for 42% and 32% of the variation in community composition, respectively. Besides, biochar increased Fe and P concentrations in root cell walls, which retained more Cr. Overall, Cr stress in rice under biochar treatment was relieved through increasing IP formation and altering subcellular distribution. These mechanistic insights had important implications for reducing Cr uptake by rice.