Fe Content Research Articles

[Pollution Characteristics, Source, and Health Risk Assessment of Metal Elements in PM2.5 Between Winter and Spring in Zhengzhou].

A total of 18 metal elements in ambient PM2.5 in Zhengzhou were continuously determined using an online heavy metal observation instrument in January and April, 2021, and the changes in element concentrations were analyzed. Metal elements were traced via enrichment factors, positive matrix factorization (PMF), and a characteristic radar chart. The US EPA health risk assessment model was used to assess the health risks of heavy metals, and the backward trajectory method and the concentration-weighted trajectory (CWT) method were used to evaluate the potential source regions of health risks. The results showed that the element concentrations were higher in spring, and the sum of Fe, Ca, Si, and Al concentrations accounted for 89.8% and 87.5% of the total element concentrations in winter and spring, respectively. Cd was enriched significantly, which was related to human activities. The concentrations of Pb, Se, Zn, Ni, Sb, and K in winter and Cr, Ni, Fe, Mn, V, Ba, Ca, K, Si, and Al in spring increased with the increasing pollution level. The results of PMF and the characteristic radar chart showed that the main sources of metal elements in winter and spring were industry, crust, motor vehicles, and mixed combustion, with industry and mixed combustion pollution occurring more often in winter and crust pollution occurring more often in spring. Significant non-carcinogenic risks existed in both winter and spring with more severe health risks in winter, and Mn caused significant non-carcinogenic risks. The health risks in winter were mainly influenced by Zhengzhou and surrounding cities and long-distance transport in the northwest, and the health risks in spring were mainly influenced by Zhengzhou and surrounding cities.

275 Assessment of changes in hemoglobin concentration (Hb) in sows and their offspring over two consecutive reproductive cycles

Abstract There remains a knowledge gap regarding changes in hematological parameters, such as Hb, throughout the reproductive cycle of a sow. The principle aim of this study was to assess Hb concentartions in sows and their offspring over at least two consecutive reproductive cycles. Blood Hb measurements were initiated during the gilt stage and continued through parities 1 and 2, with measurements taken at six time points (d 30, 60, 90, and 112 of gestation; d 2 and 17 of lactation) involving a total of 13 sows. Sow body weight (BW) during gestation was 193.2 ± 38.1 kg for parity 1 and 220.7 ± 26.2 kg for parity 2; in lactation, sow BW was 201.5 ± 14.3 kg for parity 1 and 214.0 ± 19.6 kg for parity 2. Sow daily iron (Fe) intake, based on analyzed Fe content, was 0.621 ± 0.06 g during gestation and 1.79 ± 0.15 g during lactation across parities 1 and 2, which represents more than a 2-fold greater Fe intake than NRC 2012 requirement estimates. All liveborn piglets (n = 204 for parity 1; n = 201 for parity 2) underwent Hb measurements. Blood Hb concentrations were assessed within 24 h of birth before iron supplementation (200 mg iron dextran) and again at 17 d of age. Sows and piglets were classified as either anemic (Hb < 10 g/dL) or non-anemic (Hb ≥ 10 g/dL). Analysis of variance included the main effect of day, parity and their interaction based on Tukey’s comparison. In gestation Hb was less (P = 0.03) at d 90 in parity 1 and at d 90 and 112 in parity 2 (Table 1). Across parity, Hb was less (P = 0.02) at d 60 in parity 2. In lactation, Hb was least (P = 0.0002) at d 17 in parity 1 where sows were deemed anemic; in parity 2, sows were deemed anemic throughout lactation. The total number of piglets born and born alive was 17.15 ± 2.03 and 16.0 ± 1.9, respectively, for parity 1, and 17.0 ± 3.11 and 15.85 ± 2.41, respectively, for parity 2. Regardless of parity, piglet Hb was greater (P < 0.02) at weaning compared with birth. However, Hb concentrations were greater (P < 0.0001) at both time points in parity 2 piglets. There was a reduced incidence of anemia at birth (39.1% vs. 59.02%, respectively) and weaning (14.2% vs 36.1%, respectively) among piglets born in parity 2 compared with parity 1. The decline in sow Hb status with parity, particularly in lactation, suggests the need to explore strategies to improve Hb in sows with advancing parity. Alternatively, piglet Hb status improved with parity, indicating a need to modify iron supplementation methods to facilitate greater Hb in parity 1 litters.

Genomic Advances in Biofortification of Iron and Zinc in Wheat (Triticum aestivum L.)

Majority of population that depend on wheat are found to be deficient in iron and zinc. About 20% of calories worldwide are derived from wheat. Milling of wheat reduces the bioavaibility of Fe and Zn in wheat grains. Micronutrient deficiency is the main cause of malnutrition worldwide and hidden hunger in underdeveloped countries. To overcome this problem it becomes necessary to develop varieties that are rich in iron and zinc content. Biofortification gets around these issues by enhancing the micronutrient content of wheat. The genetic approaches of biofortification particularly the non-conventional methods have proved to be the most efficient ones. These method includes QTL mapping approach, GWAS and transgenics. Although conventional methods for a long time has been used for developing varieties of wheat rich in Fe and Zn but conventional breeding for certain traits may be inconvenient and time-consuming and are prone to errors due to their reliance on traditional phenotyping or visual assessments. Several research have been undertaken to map QTLs of Fe and Zn concentration in wheat grains and have been used in elite genetic backgrounds to improve micronutrient content. Genomic studies revealed through GWAS exhibit high QTL resolution and allele coverage, which can be used for improvement of Fe and Zn content in wheat. Genetic engineering techniques or transgenics approaches allows genetic alteration of crops to improve the nutritional quality of wheat. Genomic approach of biofortification of wheat has proved to be the most efficient methods for increasing iron and zinc content in the crop.

Impact of air quality on the health of present-day workers in an Asbestos roof manufacturing industry, Sri Lanka.

The study's objective was to determine the air quality in an asbestos-related industry and its impact on current workers' respiratory health. Seventy-seven air and 65 dust samples were collected at 5-day intervals in an asbestos roofing sheets production factory in Sri Lanka having two production facilities. Sampling was performed in ten sites: Defective sheets-storage, Production-plant, Pulverizer, Cement-silo, and Loading-area. A detailed questionnaire and medical screening were conducted on 264 workers, including Lung Function Tests (LFT) and chest X-rays. Asbestos fibres were observed in deposited dust samples collected from seven sites. Free chrysotile fibres were absent in the breathing air samples. Scanning Electron Microscopy confirmed the presence of asbestos fibres, and the Energy Dispersive X-ray analysis revealed Mg, O, and Si in depositions. The average concentrations of trace metals were Cd-2.74, Pb-17.18, Ni-46.68, Cr-81.01, As-7.12, Co-6.77, and Cu-43.04mg/kg. The average Zn, Al, Mg, and Fe concentrations were within 0.2-163g/kg. The highest concentrations of PM2.52.5 and PM1010, 258 and 387µg/m3, respectively, were observed in the Pulverizer site. Forty-four workers had respiratory symptoms, 64 presented LFT abnormalities, 5 indicated chest irregularities, 35.98% were smokers, and 37.5% of workers with abnormal LFT results were smokers. The correlation coefficients between LFT results and work duration with respiratory symptoms and work duration and chest X-ray results were 0.022 and 0.011, respectively. In conclusion, most pulmonary disorders observed cannot directly correlate to Asbestos exposure due to negligible fibres in breathing air, but fibres in the depositions and dust can influence the pulmonary health of the employees.

Crystal Chemistry and Formation of Authigenic Chlorite: Influence on Tight Sandstone Reservoir in the Yanchang Formation, Ordos Basin, China

Authigenic chlorite is a crucial diagenetic cement that significant impacts tight sandstone reservoirs. The occurrence, crystal chemistry, formation and influences on reservoirs of different authigenic chlorite types were studied in the Yanchang Formation tight sandstones from the Ordos Basin. This study identified two primary types of chlorites: alteration chlorite and autochthonous authigenic chlorite. The alteration chlorite, characterizing by high Fe, Mg, Ti and AlIV contents and low Si and AlVI contents, originated from biotite during diagenesis. The autochthonous authigenic chlorite can be further classified into grain-coating, pore-lining, and pore-filling chlorite. The grain-coating chlorite features thin layers and limited crystal form. During the syndiagenetic stage, Fe2+ and Mg2+ carried by water adsorbed onto the particle surfaces. Additionally, the grain-coating chlorite contains relatively high K content due to the hydrolysis of biotite during the eodiagenetic A stage. The pore-lining chlorite formed during the prolonged eodiagenetic B stage. The biotite and abundant intermediate-basic magmatic fragments released Fe2+ and Mg2+, contributing to the widespread development of euhedral pore-lining chlorite. Notably, the pore-lining chlorite displayed elemental composition variations from the grain edge to the pore center, with increased Fe, Mg and AlIV, and decreased K and AlVI. The pore-filling chlorite formed locally resulted from Fe2+ and Mg2+ crystallization due to the hydrolysis of intermediate-basic magmatic rocks and the dissolution early formed chlorite. The pore-filling chlorite contains the most Fe, Mg and Mn contents and the least K content. Overall, authigenic chlorite acts as a "double-edged sword" in tight sandstone reservoir. The grain-coating and grain-lining chlorite enhance the mechanical strength, resist compaction, and inhibit quartz overgrowth, while pore-filling chlorite trends to obstruct pore throats and break reservoir quality. This study provides valuable insights into the detailed control factors influencing reservoir quality and can serve as a reference for further research.

Mechanism for Fe(III) to decrease cadmium uptake of wheat plant: Rhizosphere passivation, competitive absorption and physiological regulation

The presence of dissolved Fe(III) and Fe(III)-containing minerals has been found to alleviate cadmium (Cd) accumulation in wheat plants grown in Cd-contaminated soils, but the specific mechanism remains elusive. In this work, hydroponic experiments were conducted to dissect the mechanism for dissolved Fe(III) (0–2000 μmol L−1) to decrease Cd uptake of wheat plants and study the influence of Fe(III) concentration and Cd(II) pollution level (0–20 μmol L−1) on the Cd uptake process. The results indicated that dissolved Fe(III) significantly decreased Cd uptake through rhizosphere passivation, competitive absorption, and physiological regulation. The formation of poorly crystalline Fe(III) oxides facilitated the adsorption and immobilization of Cd(II) on the rhizoplane (over 80.4 %). In wheat rhizosphere, the content of CaCl2-extractable Cd decreased by 52.7 % when Fe(III) concentration was controlled at 2000 μmol L−1, and the presence of Fe(III) may reduce the formation of Cd(II)-organic acid complexes (including malic acid and succinic acid secreted by wheat roots), which could be attributed to competitive reactions. Down-regulation of Cd uptake genes (TaNramp5-a and TaNramp5-b) and transport genes (TaHMA3-a, TaHMA3-b and TaHMA2), along with up-regulation of the Cd efflux gene TaPDR8-4A7A, contributed much to the reduction of Cd accumulation in wheat plants in the presence of Fe(III). The inhibitory effect of Fe(III) on Cd uptake and transport in wheat plants declined with increasing Cd(II) concentration, particularly at 20 μmol L−1. This work provides important implications for remediating Cd-contaminated farmland soil and ensuring the safe production of wheat by using dissolved Fe(III) and Fe(III)-containing minerals.

Wildfire Ashes from the Wildland-Urban Interface Alter Vibrio vulnificus Growth and Gene Expression.

Climate change-induced stressors are contributing to the emergence of infectious diseases, including those caused by marine bacterial pathogens such as Vibrio spp. These stressors alter Vibrio temporal and geographical distribution, resulting in increased spread, exposure, and infection rates, thus facilitating greater Vibrio-human interactions. Concurrently, wildfires are increasing in size, severity, frequency, and spread in the built environment due to climate change, resulting in the emission of contaminants of emerging concern. This study aimed to understand the potential effects of urban interface wildfire ashes on Vibrio vulnificus (V. vulnificus) growth and gene expression using transcriptomic approaches. V. vulnificus was exposed to structural and vegetation ashes and analyzed to identify differentially expressed genes using the HTSeq-DESeq2 strategy. Exposure to wildfire ash altered V. vulnificus growth and gene expression, depending on the trace metal composition of the ash. The high Fe content of the vegetation ash enhanced bacterial growth, while the high Cu, As, and Cr content of the structural ash suppressed growth. Additionally, the overall pattern of upregulated genes and pathways suggests increased virulence potential due to the selection of metal- and antibiotic-resistant strains. Therefore, mixed fire ashes transported and deposited into coastal zones may lead to the selection of environmental reservoirs of Vibrio strains with enhanced antibiotic resistance profiles, increasing public health risk.

Effects of Fe on microstructure and mechanical properties of CoCrNiFeAl multi-principle elements alloys

Precipitation and twinning strengthening mechanisms have been extensively investigated to improve the yield strength and ductility of face-centered cubic (FCC) multi-principle elements alloys (MPEAs). Compared with well-studied Al0.3CoCrFeNi in CoCrFeNi system, the microstructure and mechanical properties of a new designed CoCrNiFe0.62Al0.38 MPEA with lower Fe content were evaluated by transmission electron microscopy and tensile tests, respectively. Higher volume fraction of B2 nanoprecipitates and early deformation twining within FCC matrix were proposed to play key roles in improving the synergy strength and ductility of the AlCoCrFeNi system. The experimental results presented herein not only provide insight into how transition metal element affect precipitation and twining process of B2 phase reinforced FCC MPEAs, but also demonstrate useful guidance for the development of precipitation hardened CoCrFeNi system other than adjusting conventional elements such as Al, Ti, Ta, etc.

Electrical resistivity and magnetoresistance of Sr3Fe2+xMo1–xO9–3x/2 (x = 0.45, 0.60, and 1.00) prepared by the solid-state reaction

In this paper, we focus on understanding the behavior of the temperature dependence of electrical resistivity (ρ) and magnetoresistance (MR) in Sr3Fe2+xMo1–xO9–3x/2 perovskites with x = 0.45, 0.60, and 1.00. Three polycrystalline materials were synthesized using conventional solid-state reaction techniques. Rietveld analysis of room-temperature X-ray diffraction data reveals that all three compositions crystallize in tetragonal symmetry; where x = 0.45 and 0.60 undergo an I4/mcm space group, while x = 1.00 adopts a P4/mmm space group. Electrical resistivity measurements carried out at magnetic fields (0 and 1 T) reveal the presence of a transition from the ferromagnetic phase to the paramagnetic phase in the vicinity of the TMI. The metal-insulator transition temperature (TMI) decreases with increasing Fe content and rises slightly with changing magnetic field from 0 to 1 T. The magnetoresistance (MR) of the SrFeO3–δ sample (x = 1.00) has a large value of about 63.6%, indicating that it can be exploited for certain devices. A variety of theoretical models are used to study the behavior of electrical resistivity in various temperature ranges, showing excellent agreement with experimental results.

Orange luminescence of α-Al2O3 related to clusters consisting of F centers and divalent cations.

The orange luminescence of α-Al2O3 under UV excitation is characterized by a 2.07-eV orange broadband emission that has not yet been elucidated. This emission is present in natural and synthetic crystals and powders, as well as in Be-treated samples. All orange-luminescent materials have low Fe concentration (mostly <1000 ppm) with traces of divalent cations, mostly Mg, or Be in Be-diffused material (dozens of ppm). Mg2+, Mn2+, and Be2+ cations substitute for trivalent Al. To accommodate the charge deficit, several defects are created, including oxygen vacancies also called F centers. Indeed, our excitation spectra revealed the presence of several different F centers (F, F+, and clustered F2, F2 +, F2 2+) in those samples. However, the thermal stability and the measured luminescence lifetimes do not match with previously reported characteristics of isolated F centers. Based on our experiments, we suggest that a complex aggregate of two F centers (F2 2+) trapped at divalent cations is a major cause of this uncommon microsecond lifetime emission, even if a variety of other defects, including Cr3+, V3+, or interstitial Al3+, are present.

Not so fast: Million-years of metal precipitation in Mississippi Valley type deposits inferred from in-situ petrochronology of hydrothermal carbonates

Mississippi Valley-type (MVT) deposits contain about 20% of global zinc resources and host critical raw materials crucial to the development of green technologies. Despite their economic and strategic importance, there is a lack of consensus on the duration of mineralizing fluid flow events in MVT systems. This study couples in-situ U-Pb dating with Sr-isotope and trace element analysis of syn- and post-ore gangue carbonates to establish: (1) timing and duration, (2) redox evolution, and (3) flow rates of mineralizing fluids in the world-class San Vicente Zn-(Pb) deposit (Peru). New radiometric ages bracket the crystallization of syn-mineralization dolomite, characterized by high Fe and Mn contents and Sr isotopic values overlapping with that of host carbonates, between 103.2 ± 4.1 Ma and 70.6 ± 5.6 Ma. This age interval reveals a direct genetic relationship between flow of mineralizing fluids and late Cretaceous Andean compressional tectonics. Basinal fluid expulsion coeval with known tectonic events continues in the district until Pliocene times, driving episodic crystallization of post-ore hydrothermal carbonates between 61.6 ± 9.3 and 2.7 ± 0.2 Ma. The low Mn and Fe content and high 87Sr/86Sr values characteristic of these post-ore, bedding-parallel and cross-cutting carbonate veins indicate a colder, oxidized environment. Our findings highlight the contribution of paired carbonate geochemistry and U-Pb geochronology in drawing links between tectonic events, fluid expulsion and the waxing and waning of mineralization potential in foreland basins. The results of this study challenge our understanding of timescales in MVT systems and imply that anomalous metal enrichment in basinal fluids over a short temporal interval is not a necessary precondition to form economic-sized, sediment-hosted Zn-Pb deposits. Rather, it is the coexistence of a focused fluid flow in an interconnected aquifer with suitable metal depositional mechanisms over a prolonged period of time (106–107 yr) that allows precipitation of economic amount of base metals at a specific site in the upper crust.

Ecophysiological responses of Phragmites australis populations to a tidal flat gradient in the Yangtze River Estuary, China

Phragmites australis is a prevalent species in the Chongming Dongtan wetland and is capable of thriving in various tidal flat environments, including high salinity habitats. P. australis population displays inconsistent ecological performances, highlighting the need to uncover their survival strategies and mechanisms in tidal flats with diverse soil salinities. Upon comparing functional traits of P. australis at multiple tidal flats (low, middle, and high) and their responses to soil physicochemical properties, this study aimed to clarify the salt-tolerant strategy of P. australis and the corresponding mechanisms. These results showed that leaf characteristics, such as specific leaf area and leaf dry matter content, demonstrated more robust stability to soil salinity than shoot height and dry weight. Furthermore, as salt stress intensified, the activities of superoxide dismutase (SOD), catalase (CAT) and peroxisome (POD) in P. australis leaves at low tidal flat exhibited an increased upward trend compared to those at other tidal flats. The molecular mechanism of salt tolerance in Phragmites australis across various habitats was investigated using transcriptome sequencing. Weighted correlation network analysis (WGCNA) combined with differentially expressed genes (DEGs) screened out 3 modules closely related to high salt tolerance and identified 105 core genes crucial for high salt tolerance. Further research was carried out on the few degraded populations at low tidal flat, and 25 core genes were identified by combining WGCNA and DEGs. A decrease in the activity of ferroptosis marker gonyautoxin-4 and an increase in the content of Fe3+ in the degenerated group were observed, indicating that ferroptosis might participate in degradation. Furthermore, correlation analysis indicated a possible regulatory network between salt tolerance and ferroptosis. In short, this study provided new insights into the salt tolerance mechanism of P. australis population along tidal flats.

Analize Die Casting process and Structure of HDF 12 Material for Lower Arm

Steel is part of raw material for manufacturing process making a product. Ferro Casting Ductile is part of manufacturing process from iron ore to be metal part using casting process. Die casting is a part of manufacturing process especially in automotive industries for engine of vehicle production process. this research will be focus on casting process, Ferro Casting Ductile (FCD). In this research using material steel HDF 12 Material, in this process production Magnesium, Pig Iron, Scrap, Silicon, Carburizer, Inoculant and Slagtol.  Manufacturing process is melting process of all raw material using temperature (melting point) at 1100 - 1400 ºC. When Specimen finish to process production will be analyze using spicrometer and SM machine for check of characteristic material and structure for crack issue. The result show that after casting process, the HDF12 have composition rate iron (Fe) content, namely 93.37% and also carbon (C) 3.82% and silicon (Si) 2.31% after check using. As visual check after die casting, lower arm is there no any crack, flash, flow mark finding by visual check inspection result. SEM Measurement check result until 300μm the result show that no any finding crack issue and result of Tensile strength of material Lower Arm upper limit is 433Kgf/cm2 and lower limit is 420 Kgf/cm and Elongation is 32%.

Water-saving irrigation mitigates methane emissions from paddy fields: The role of iron

Iron (Fe) and methane (CH4) emissions play crucial roles in the carbon cycling of paddy field ecosystems. However, little is known about the effect and mechanism of Fe transformation on the CH4 emission from paddy fields, especially with different water management methods. In this study, the dynamic changes in CH4 emissions and different forms of Fe and soil organic carbon content were observed in paddy fields under flooded irrigation (FI) and water-saving irrigation (WSI) (including intermittent irrigation (II) and controlled irrigation (CI)). In addition, the structural equation model was used to clarify the response relationship between CH4 emissions and Fe ions in paddy fields. The results indicate that the cumulative CH4 emissions under WSI were reduced by 29.03–61.29%. The reasons are as follows (i) WSI increased the oxidation ability of Fe to CH4 by increasing the soil ferric iron (Fe3+) content in paddy fields; (ii) WSI could reduce the substrate utilization by methanogens by transforming the Fe oxide forms to increase the binding capacity of Fe to dissolved organic carbon, which reduced the CH4 production. In addition, compared with II, CI had higher soil Fe3+ content, Fe-bound organic carbon content, and lower acetate content, so it had lower CH4 production capacity. In summary, WSI promotes the direct oxidation of CH4 by Fe3+ in paddy fields and indirectly reduces CH4 production by facilitating the combination of Fe oxides with the substrates. These findings deepen our understanding of the mechanisms of CH4 emission in paddy fields and provide new insights for research on carbon sequestration and emission reduction in paddy field ecosystems.

Clonal variation depending on Cu, Fe and Zn element concentrations in seed orchards

In order to increase the existing forest assets and to maintain sustainable forestry, breeding studies are carried out in forestry. One of the most important practices in these breeding studies is seed orchards. The purpose of seed orchards is to obtain better quality seeds per unit area. In this study, plant nutritional elements were used for the first time to determine clonal variation. The antagonism of nutrients and their accumulation rate in clones were investigated. The research was carried out in the Scots pine (Pinus sylvstris) clonal seed orchard in Taşköprü. Needle samples were taken from 8 ramets of 30 clones in the seed orchard in 3 replications and 240 trees were randomly sampled. In addition, soil samples were taken from the seed orchard. The samples taken were first washed in the laboratory and then two different drying processes were applied to the samples. After drying, samples were prepared by the melting method and then Cu, Fe and Zn element concentration analyzes were performed with the ICP-OES device. The results obtained were evaluated by analysis of variance and Tukey test with the help of Minitab 18 package program and differences between clones were tried to be determined depending on element concentrations. In the findings obtained, it was determined that there were significant differences between the clones in terms of the studied elements at the p&lt;0.05 probability level.

The Arabidopsis RTH plays an important role in regulation of iron (Fe) absorption and transport.

RTH may activate Fe assimilation related genes to promote Fe absorption, transport and accumulation in Arabidopsis. Iron (Fe) is an important nutrient element. The Fe absorption and transport in plants are well investigated over the past decade. Our previous work indicated that RTE1-HOMOLOG (RTH), the homologous gene of reversion-to-ethylene sensitivity 1 (RTE1), plays a role in ethylene signaling pathway. However, its function in Fe absorption and transport is largely unknown. In the present study, we found that RTH was expressed in absorptive tissue and conducting tissue, including root hairs, root vascular bundle, and leaf veins. Under high Fe concentration, the seedling growth of rth-1 mutant was better, while the RTH overexpression lines were retarded compared to the wild type (Col-0). When treated with EDTA-Fe3+ (400μM), the chlorophyll content and ion leakage rate were higher and lower in rth-1 than those of Col-0, respectively. By contrast, the chlorophyll contents and ion leakage rates of RTH overexpression lines were decreased and hastened compared with Col-0, respectively. Fe measurement indicated that the Fe contents of rth-1 were lower than those of Col-0, whereas those of RTH overexpression lines were comparably higher. Gene expression analysis revealed that Fe absorption and transport genes AHA2, IRT1, FIT, FPN1, and YSL1 decreased in rth-1 but increased in RTH overexpression lines compared with Col-0. Additionally, Y2H (yeast two-hybrid) and BiFC (bimolecular fluorescence complementation) assays showed that RTH can physically interact with hemoglobin 1 (HB1) and HB2. All these findings suggest that RTH may play an important role in regulation of Fe absorption, transport, and accumulation in Arabidopsis.

Contrasting effects of increasing dissolved iron on photosynthesis and O2 availability in the gastric cavity of two Mediterranean corals.

Iron (Fe) plays a fundamental role in coral symbiosis, supporting photosynthesis, respiration, and many important enzymatic reactions. However, the extent to which corals are limited by Fe and their metabolic responses to inorganic Fe enrichment remains to be understood. We used respirometry, variable chlorophyll fluorescence, and O2 microsensors to investigate the impact of increasing Fe(III) concentrations (20, 50, and 100 nM) on the photosynthetic capacity of two Mediterranean coral species, Cladocora caespitosa and Oculina patagonica. While the bioavailability of inorganic Fe can rapidly decrease, we nevertheless observed significant physiological effects at all Fe concentrations. In C. caespitosa, exposure to 50 nM Fe(III) increased rates of respiration and photosynthesis, while the relative electron transport rate (rETR(II)) decreased at higher Fe(III) exposure (100 nM). In contrast, O. patagonica reduced respiration, photosynthesis rates, and maximum PSII quantum yield (Fv/Fm) across all iron enrichments. Both corals exhibited increased hypoxia (<50µmol O2 L-1) within their gastric cavity at night when exposed to 50 and 100 nM Fe(III), leading to increased polyp contraction time and reduced O2 exchange with the surrounding water. Our results indicate that C. caespitosa, but not O.patagonica, might be limited in Fe for achieving maximal photosynthetic efficiency. Understanding the multifaceted role of iron in corals' health and their response to environmental change is crucial for effective coral conservation.

Interference and Elimination of Fe3+ During Spectrophotometric Testing of Typical Pollutants in Coking Wastewater

As typical pollutants in coking wastewater, pyridine, indole, quinoline, and phenol have the advantages of rapidity and accuracy when determined in aqueous solution using UV spectrophotometry, but the presence of other substances in the water can interfere with the results. In this study, the spectrophotometric detection of pyridine, indole, quinoline, and phenol in coking wastewater was interfered with by Fe3+. To minimize this interference, hydroxylamine hydrochloride (HA) was selected as a masking agent to eliminate the interference of Fe3+ on the detection. The results indicated that spectrophotometric determination was significantly affected by Fe3+, and the level of interference increased with the concentration of Fe3+. HA can effectively reduce the absorbance of Fe3+ in the wavelength range of 250-350 nm. It exhibits a strong masking effect on the determination of Fe3+ in indole and phenol solutions, but it hampers the detection of pyridine and quinoline. HA has a better elimination effect on the interference of different concentrations of Fe3+, which can make the relative error of the determination results of indole and phenol less than 5% and 10%, respectively.

Essential and toxic elements analysis of wild boar tissues from north-eastern Romania and health risk implications

IntroductionThe level of essential minerals in meat is an important factor in human nutrition and health. Meat from responsibly managed wildlife is an alternative raw material with considerable nutritional benefits. Meat from hunted animals has essential and non-essential elements for the human body. It is important to carefully monitor the levels of heavy metals accumulated in the tissues of hunted animals in polluted areas to ensure food safety and environmental contamination. High levels of heavy metals in food and the environment can pose a danger to human health.MethodsThe study aims to investigate the levels of essential mineral elements and heavy metals in the muscle tissue and organs of wild boar harvested through the herd density control plan over the last decade in north-eastern Romania.Results and discussionThe statistical analysis indicates that the age of the animals had a significant impact on Fe, Cu, and Zn levels in Longissimus lumborum. In the kidney a highly significant difference in Fe content by sex, with males showing higher values than females. The sex was shown to significantly influence the Mg levels. However, there are concerns about the accumulation of heavy metals such as Lead (Pb) and Cadmium (Cd), which may hurt the health of game meat consumers in the study area. Cd level it shows significant differences according to both age and sex, with higher concentrations in adults and males. Statistical analysis shows a negative correlation between Fe and Zn concentrations in muscle samples, while a positive correlation was found between Fe and Mn in kidney samples. There was also a positive association between Zn and Cu in muscle samples, but a negative association in kidney samples. Principal component analysis shows significant variation in essential element and heavy metals data between muscle and kidney samples. The loading plot shows a direct correlation between Pb and Cu and between Pb and Cd. However, an opposite correlation also is observed between Cu and Mg, Cd and Mg, and Pb and Mg. HQ (Hazard Quotient) for children compared to adults indicates a potentially higher risk associated with meat consumption among children because children are more vulnerable than adults. We report for the first time, to the best authors’ knowledge, various levels of essential minerals and exceeded maximum admitted level of heavy metals in the muscle tissues and kidneys of Sus scrofa ferus from Romania intended for human consumption, moreover, our findings highlight the need for strict monitoring and implementation of appropriate corrective measures, given the significant percentages of muscle and kidney samples exceeding the allowable limits for two of the most common toxic metals in the environment.

Fe(II)/Fe(III) cycle actuating a novel process to remove organics in waste pit mud from Maotai: Performance and mechanism

In this study, a novel method relying on iron cycle through intermittent aeration was proposed to treat organic matter in waste sealed pit mud from Moutai. Firstly, ferrihydrite was used to verify dissimilatory iron reduction could remove organics from the pit mud; then, the effect of iron cycle induced by intermittent aeration on organics was investigated. The results showed that the removal efficiency of organics was increased by 8.2 % after the addition of ferrihydrite, then intermittent aeration was carried out, Fe(II) content decreased after aeration and increased again after stopping aeration, indicating that iron cycle occurred. Additionally, the total chemical oxygen demand (TCOD) content further decreased by18.8 % in the reactor with intermittent aeration, significantly higher than that in the unaerated group (11.8 %) (p < 0.05). Due to the short aeration time (about once a week, 200–500 mL/min, 30 min for each aeration), aerobic microorganisms were undetected, which further indicated that iron cycle enhanced the removal of organics. Finally, intermittent aeration was conducted in the fermentation system of pit mud without adding iron, and the indigenous iron in the pit mud was also recycled. After 31 days, the TCOD removal efficiency increased by 15.6 % in the aeration group compared with that in the control group. Microbial analysis showed that some microorganism that degraded refractory organics, including iron reducing bacteria, were enriched in the aerated reactors, such as WCHB1–32, ADurb. bin053–1, Lentimicrobium, and Aneurinibacillus, Geobacteraceae. These indicated that organic matter removal can be enhanced by relying on its indigenous iron.