Variable Element Research Articles

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.

Feasibility of C2 Lamina Screw Placement in a New Zealand Cohort: Computed Tomography Analysis According to Ethnicity and Gender.

Previous analyses have suggested variations in cervical spine canal morphology according to ethnicity, possibly in part due to variations in the posterior elements. The potential for these variations to affect the placement of instrumentation is uncertain. The aim of this study was to report on the feasibility of C2 lamina screw insertion in a New Zealand cohort including analysis of Māori, the indigenous people of New Zealand. A trauma computed tomography database was accessed to identify suitable images. On axial images, where the isthmus was at its widest, the outer diameter (OD) and inner diameter (ID) of the lamina were measured. Screw length was measured from a proposed entry point to the contralateral junction of the lamina and lateral mass. The spinolaminar angle was measured as the angle subtended by the screw trajectory and midsagittal plane. A 5.5-mm OD was accepted as a threshold for the feasibility of lamina screw placement. One hundred eighty-seven images were assessed: 115 New Zealand European and 72 Māori. The mean age of the cohort was 41.9 years (SD 19.6), and most patients (64%) were men. For the entire cohort, mean OD was 6.6 and 6.8 mm on the right and left, respectively; the mean inner diameter was 3.5 and 3.8 mm; mean screw length was 31.5 and 31.5 mm; and mean spinolaminar angle was 46.0° and 46.1°. C2 lamina screw placement was feasible in a majority of patients. Considering only Māori patients, placement was feasible in 96% of right and 94% of left laminae in men but 72% of right and 72% of left laminae in women. In a majority of patients, C2 lamina screw placement is feasible. However, advanced imaging must be carefully assessed preoperatively because data suggest that Māori women may not necessarily have optimal anatomy.Clinical RelevanceCare needs to be taken when assessing and planning surgery inpatients of different ethnicities because variations may exist in the morphology of the posterior elements of C2, leading to variation in optimal fixation strategy.Level of Evidence3.

Tracking the Variations in Trace and Heavy Elements in Smoking Products Marketed in Oman and Egypt: Risk Assessment After Implementation of Constraining Protocols.

Tobacco smoking is becoming one of the major worldwide concerns regarding environmental pollution as well as health threats. In 2005, the World Health Organization (WHO) released the Framework Convention On Tobacco Control (FCTC), which outlined protocols for controlling tobacco products. Oman was one of the leading countries to follow these protocols; however, Egypt has only followed these protocols recently in 2020. One of the main challenges in tobacco product control is the variation in their trace element's types and amounts from country to country owing to differences in agriculture techniques and used chemical additives. Smoking releases different toxic metal ions found in them into the air, and hence, analyzing trace amounts of metals in tobacco smoking products is becoming more critical. The proposed research aims to evaluate the current levels of 11 heavy metals (namely, As, Pb, Cd, Co, Cr, Be, Ba, Mn, Ni, Fe, and Hg) in 22 tobacco products available in Egypt and Oman using inductively coupled plasma optical emission spectroscopy and a direct mercury analyzer. Although some elements such as Be, Co, and Cd were absent, the positive detection of As and Pb and the levels of Ba, Cr, and Ni are still alarming, especially for heavy smokers. The obtained results were then statistically related to previously published data in 2017 to explore the effectiveness of implementing the FCTC protocols within the Egyptian market. The outcomes suggested a positive impact of FCTC protocol implementation in Egypt, besides the lower levels of elemental content for Omani products compared to the Egyptian market.

Phenolic, Amino Acid, Mineral, and Vitamin Contents during Berry Development in ‘Italia’ and ‘Bronx Seedless’ Grape Cultivars

Understanding the variations in amino acids, phenolic compounds, elements, and vitamins between grape varieties is essential for optimizing grape production, fine-tuning dietary recommendations, and harnessing the health potential of grapes. In this regard, this comprehensive study investigated the compositional diversity of two distinct table grape cultivars, ‘Bronx Seedless’ and ‘Italia’, at various critical phenological stages (BBCH-77, -79, -81, -83, -85, and -89). The research findings demonstrated remarkable differences in the concentrations of key nutritional components. Bronx Seedless consistently exhibited higher levels of several amino acids, including glutamate, phenylalanine, and aspartate with concentrations reaching 49.6, 52.7, and 24.8 pmol μL−1, respectively, in contrast to Italia. Regarding phenolic compounds, Italia emerged as the richer source, with concentrations notably higher for compounds such as vanillic acid (18.2 µg g−1 FW) and gallic acid (37.4 µg g−1 FW). Mineral analysis revealed variable concentrations, with Italia grapes containing higher levels of Fe (91.0 mg/kg) compared to Bronx Seedless (87.1 mg/kg); however, Bronx Seedless had slightly elevated levels of K (31,089 mg/kg) compared to Italia (28,184 mg/kg). Concidering vitamins, Italia grapes showcased superior levels of Vitamin B1 (14.1 mg/100 g FW) and Vitamin A (11.0 mg/100 g FW), while Bronx Seedless had higher concentrations of Vitamin B6 (29.5 mg/kg), C (3.9 mg/100 g FW) and Vitamin B2 (36.9 mg/100 g FW). Principal component analysis (PCA) elucidated complex relationships within these components, offering insights into potential correlations and interactions. The heatmap visualization further indicated the concentration gradients across various samples, unveiling the intricate nutritional profiles of these grape cultivars. This research can aid grape growers and consumers in making informed decisions about grape cultivars and their corresponding health advantages.

Alkali Metal–Substitution–Induced Confinement Effect for Designing High Phase–Transition–Temperature Molecular–Based Compounds Exhibiting Strong Photoluminescence

AbstractOrganic–inorganic hybrid phase–transition molecular materials have attracted increasing attention due to their excellent properties of combining inorganic and organic components. However, few research has been conducted on rare‐earth–based bimetallic organic–inorganic hybrids. Here, we successfully constructed a series of rare–earth–based organic–inorganic hybrid multifunctional materials, (C6H14N2)2EuX(NO3)6O2 (X=Na, K, Rb), with reversible phase transition, switchable dielectric, photoluminescence and semiconductor properties. Specifically, the phase‐transition temperature of three compounds are determined to be 364, 405 and 440 K, respectively. By the confinement effect caused by the variation of alkali metal elements in the two–dimensional structure, the phase transition temperature is successfully increased by 76 K. Meanwhile, the solid–state photoluminescence of three compounds displays bright red light at room temperature. Additionally, the bandgaps of three compounds are determined to be 3.21, 3.53 and 3.32 eV, respectively. It is expected that the strategy of alkali metal substitution proposed in this work will provide new thoughts for the design of multifunctional organic‐inorganic hybrid crystals.

Carbon-Sulfur isotope and major and trace element variations across the Permian–Triassic boundary on a shallow platform setting (Xiejiacao, South China)

We examined microbialites deposited near the Permian–Triassic boundary (PTB) at the Xiejiacao section of South China, including the size and morphology of pyrite framboids, carbonate carbon isotopes (δ13Ccarb), carbonate associated sulfur isotope (δ34SCAS), major and trace elements, and total organic carbon (TOC) concentrations. The microbialite unit is much thicker than the PTB beds in deeper water sections, providing more detailed geochemical records from that time. A prominent negative δ13Ccarb excursion was recognized in association with the second phase of the Permian–Triassic mass extinction (PTME), comparable with that of several other shallow platform facies sections worldwide. δ34SCAS stratigraphic profiles also show a negative excursion, with minimum values occurring slightly later than those of δ13Ccarb. The minimum peak can be calibrated to the middle part of the conodont Isarcicella staeschei Zone, corresponding to the second phase of PTME. Over all, the carbon and sulfur isotopes demonstrate a coupled long-term relationship with large negative excursions during the Permian–Triassic transition followed by gradual recovery in the lowest Triassic, represented an extremely low concentration of sulfate in the ocean during this period. In contrast, the CS isotopes are strongly decoupled within the microbialite unit, which could be linked with the oxygen-poor conditions and microbial sulfate reduction (MSR: Sulfate reducing microorganisms facilitated the precipitation of sulfide and carbonate, such as SO42− + 2CH2O → H2S + 2HCO3−). The second phase of PTME was calibrated to the top of the microbialite unit, which was marked by the second δ13Ccarb-δ34SCAS negative excursions. The distinct marine oxygen deficiency was indicated by the small pyrite framboids, relatively high values of UEF (>1) and Ce/Ce* (>0.8). Combined with the previous biostratigraphic work, we propose that continuous volcanic activity induced intensified marine anoxia, leading to biotic mortality in the second phase of the PTME. Overall, our isotopic and geochemical data, integrated with results of previous studies, provided a new explanation for the carbon and sulfur isotope variations and additional evidences into the concurrent environmental changes during the Permian–Triassic transition.

Standardization of Emergency Department Clinical Note Templates: A Retrospective Analysis Across an Integrated Health System.

This was a retrospective study before and after the implementation of a standardized ED note template. A multi-disciplinary group consensus was built around standardized note elements, provider note workflows within the electronic health record (EHR), and how to incorporate newly required medical decision-making elements. The primary outcomes measured included the proportion of ED visits using standardized note templates, and the distribution of billing codes in the six months before and after implementation. In the pre-implementation period, a total of six legacy ED note templates were being used across nine emergency departments, with the most used template accounting for approximately 36% of ED visits. Marked variations in documentation elements were noted across six legacy templates. After the implementation, 82% of ED visits system-wide used a single standardized note template. Following implementation, we observed a 1% increase in the proportion of ED visits coded as highest acuity and an unchanged proportion coded as second highest acuity. We observed a greater than two-fold increase in the use of a standardized ED note template across a 9-hospital health system in anticipation of the new 2023 coding guidelines. The development and utilization of a standardized note template format relied heavily on multi-disciplinary stakeholder engagement to inform design that worked for varied documentation practices within the EHR. After the implementation of a standardized note template, we observed better-than-anticipated coding performance.

Decomposition and Variation in Carbon and Nitrogen of Leaf Litter Mixtures in a Subtropical Mangrove Forest

The decomposition of mangrove litter plays a crucial role in material circulation and energy flow within mangrove forests. Evaluating the decomposition-based variation in biogenic elements in litter is important for improving our understanding about their biogeochemical cycling in ecosystems. The main objective of this study was to examine the interaction effect during the decomposition process of mixed Kandelia obovata and Avicennia marina litter. Variations in C and N were also determined in the decomposing leaf litter mixtures. Our findings revealed that the decomposition rates were faster in summer than in winter, and increased with the proportion of A. marina litter. After 35 days of decomposition in summer, the remaining weights for different proportions of K. obovata (KO) and A. marina (AM) were 22.9% (KO:AM = 1:2), 27.2% (KO:AM = 1:1), and 31.2% (KO:AM = 2:1), respectively. Similarly, after 49 days of decomposition in winter, the remaining weights for the different KO:AM proportions were 27.7%, 35.4%, and 44.0%, respectively. Additionally, the decomposition of mixed K. obovata and A. marina litter had an influence on C content and N release dynamics. These results provide a scientific basis for understanding the decomposition of mixed mangrove litter and its implications for material circulation and energy flow within these ecosystems.

Assessment of rare earth elements variations in five water systems in Beijing: Distribution, geochemical features, and fractionation patterns

This study investigates the distribution of rare earth elements (REEs) within the Beijing water system, specifically examining the Yongding, Chaobai, Beiyun, Jiyun, and Daqing rivers. Results indicate that the Beiyun River exhibits the highest REE concentrations, ranging from 35.95 to 59.78 μg/mL, while the Daqing River shows the lowest concentrations, ranging from 15.79 to 17.48 μg/mL. LREEs (La to Nd) predominate with a total concentration of 23.501 μg/mL, leading to a notable LREE/HREE ratio of 7.901. Positive Ce anomalies (0.70–1.11) and strong positive Eu anomalies (1.38–2.49) were observed. The study suggests that the Beijing water system's REEs may originate from geological and anthropogenic sources, such as mining and industrial activities in neighboring regions, including Inner Mongolia. These findings underscore the importance of ongoing monitoring and effective water management strategies to address REE-related environmental concerns.

Constructing stable type-II NaLiTi3O7/La2S3 heterojunctions for efficient photocatalytic charge separation and hydrogen production

Designing titanium-based oxides with efficient photogenerated carrier separation is an essential approach to enhance their photocatalytic hydrogen production performance. ALiTi3O7 possesses excellent stability, corrosion resistance, and non-toxicity. More importantly, its stoichiometry can be changed along with the variations in A-site elements and Li content, leading to tunable redox potentials of the conduction band minimum (CBM) and valence band maximum (VBM). Exploring the possible application of such materials in the field of photocatalysis is crucial for developing novel and efficient titanium-based photocatalysts. As a member of the family, NaLiTi3O7 (NLT) has a large bandgap, limiting its application as visible light photocatalyst. To address this issue, non-toxic La2S3 (LS) narrow-bandgap semiconductor was incorporated to form a heterojunction. The characterization techniques have revealed the structural and interfacial characteristics of the NLT-LS heterojunction, while the Infrared, Raman, UV–Vis diffuse reflectance spectroscopy (UV–vis DRS), X-ray photoelectron spectroscopy (XPS), and work-function tests elucidated the influence of the interface interaction on charge carrier separation mechanism. The test results further demonstrated that the formation of a type II heterojunction facilitated the transfer of photogenerated electrons from the conduction band of LS to the conduction band of NLT under light radiation. Simultaneously, the induced holes were confined to the valence band of LS. This charge transfer characteristic significantly improved the separation efficiency of the photogenerated carriers in the heterojunction, ultimately resulting in a photocatalytic hydrogen production rate of 102.4 μmol h−1 g−1 for the NLT-LS2 sample, which is ∼8 times higher than that of pure NLT and almost no decay after four cycles.

Screening of low-Cd-accumulating and Cd-remediating oilseed rape varieties using a newly indicator system for risk management of Cd-contaminated agricultural land

Although oilseed rape is frequently used as an alternative planting crop in the phytoremediation of cadmium (Cd)-contaminated agricultural land, methods for screening excellent oilseed rape varieties in this regard are inadequate. Herein, we developed a screening method that incorporates Cd accumulation, distribution, and removal, economic output, adaptability to Cd-contaminated agricultural land, and trace element variation. A Cd-adaptability index (Cd-AI) based on 10 agronomic traits was used to measure the adaptability of varieties to Cd-contaminated agricultural land. Moreover, to simplify the evaluation of adaptability, yield, biomass, and pod number with high weightings were selected to construct a discriminant function for Cd-contaminated agricultural land adaptability (correctly classified 94.20%). In a 2 year field trial, we evaluated 225 oilseed rape varieties, among which we identified two promising low-Cd-accumulating and two Cd-remediating varieties. For the low-Cd-accumulating varieties (HuYou17 and DeXingYou558), we obtained grain bioaccumulation factor (BAF) values of 0.07 and 0.08, BAFsoil-stalk values of <1, and economic outputs of RMB 25,054 and 32,292 yuan hm−2, respectively. Similarly, the Cd-remediating varieties (ZaoZa8 and YuYou61) were characterized by BAFsoil-stalk values of 4.65 and 3.61, BAFsoil-grain values of 0.16 and 0.16, Cd removals of 69.02 and 58.25 g hm−2, and economic outputs of RMB 31,189 and 24,962 yuan hm−2, respectively. Compared with the control variety, we detected lower uptakes of multiple trace elements (3–43%) in the low-Cd-accumulating varieties, whereas the Cd-remediating varieties were characterized by 15.40% and 8.30% increases in the accumulation of magnesium and zinc, respectively. Our findings augment the evaluation indices used for evaluating oilseed rape varieties and provide valuable insights from the perspectives of varietal screening and promotional application. The effective varieties identified have application potential for safe production and the remediation of agricultural land without interrupting annual agricultural production, and provide an economically sustainable approach for the utilization of Cd-contaminated agricultural land.

Genesis of the Hujiazhuang apatite-rich carbonatite complex in North China and its implication for the REE fertility of the carbonatite system

Apatite is a common REE-compatible mineral in carbonatites, so its formation can affect the REE ore-forming potential of carbonatite systems. In nature, there are numerous apatite-rich carbonatite complexes, but the petrogenesis of these complexes has long been debated. To resolve this controversy, this study conducts elemental and isotopic analyses on the Mesozoic (∼120 Ma) Hujiazhuang carbonatite complex in North China. The Hujiazhuang complex contains magnetite-calcite-apatite carbonatites and calcite carbonatites. Calcite grains from these two rock phases exhibit identical initial 87Sr/86Sr ratios (0.71027–0.71038), indicating a common parental magma derived from a metasomatized lithosphere mantle. Then, from magnetite-calcite-apatite carbonatites to calcite carbonatites, the Mg, Fe, and Mn contents of calcite continuously increase while the Sr and REE contents decrease, consistent with elemental variations of calcite during fractional crystallization of carbonatitic magma. Therefore, these two lithologies are proposed to be formed through fractional crystallization of a common magma. Notably, the Hujiazhuang carbonatite complex was derived from a metasomatized lithosphere mantle and experienced intensive fractionation, which potentially facilitate the formation of REE deposits. However, this complex cannot meet REE's economic standard. The early-stage magnetite-calcite-apatite carbonatites have high REE contents (3,675–11,075 ppm), and a positive correlation can be observed between REE and P contents in this lithology. It indicates that early, extensive crystallization of apatite led to REE dispersion, largely hindering REE enrichment in later stages. In general, this study provides important insights into the genesis of the apatite-rich carbonatite complex and advances our understanding of the REE dispersion or enrichment behaviors in carbonatite system.

Geochemical proxies for deep-sea temperature and nutrient content in cold-water bamboo corals

The impact of warming, acidification, and deoxygenation on deep-sea environments is a growing concern. Historical records are sparse, particularly at high latitudes, making climate change projections challenging. Indirect proxies, such as trace element composition of marine carbonates, such as coral skeletons, can offer an alternative method to fill data gaps but have not been realised. Here, using Laser Ablation Triple-Quadrupole Inductively Coupled Plasma Mass Spectrometry (LA-QQQ-ICP-MS), we examined micrometre-scale element variation within and between individual colonies of the bamboo coral Keratoisis sp. obtained from the Eastern Canadian Arctic. These data are used to assess the influence of biological variability on geochemical tracers for reconstructing past environmental conditions (temperature: Mg/Ca, Li/Mg, Sr/Ca, Ba/Ca, U/Ca; [Ba]SW: Ba/Ca). We place these data into context, based on a survey of literature data, using refined calibrations for high-Mg calcitic Octocorals. We find reproducible (2σ relative coefficient of variation) values of Mg/Ca (3%) and Ba/Ca (6%) along the radial growth axis of all colonies and internodes of Keratoisis sp., indicating that these signals are likely suitable for environmental reconstructions. After revising the available multi-taxa calibrations for Mg/Ca (0.316 ± 0.026 °C/mmol/mol, R2 = 0.87, p < 0.001) and Ba/Ca ([Ba/Ca μmol/mol] = 0.148 ± 0.005 [BaSW nmol/kg], R2 = 0.97, p < 0.001), we show that vital effects within and among Keratoisis sp. colonies strongly influence reconstructed temperature and [Ba]SW, but this can be somewhat mitigated by combining multiple internode transects from one colony into a single composite series. Despite the ontogenetic variability, all colonies reveal a gradual deep-water cooling trend since the early 21st century and synchronised, multi-year spikes in Ba/Ca (and hence [Ba]SW) that suggest substantial and coherent barium inputs to the seafloor. Our study confirms the reliability of Mg/Ca and Ba/Ca proxies in high-Mg bamboo corals for detecting multi-annual temperature and seawater barium variations in cold-water environments, but further investigation into micro-scale element behaviour influenced by biotic processes in these corals is needed to enhance confidence in reconstructions at finer spatial and temporal resolutions. We conclude that employing empirical calibrations based on multi-taxa approaches can increase the certainty of capturing regional changes in the environment more accurately than a single species calibration, while leveraging multiple element series to account for biological-induced variability improves single colony reconstructions.

From source to surface: clues from garnet-bearing Carboniferous silicic volcanic rocks, Iberian Pyrite Belt, Portugal

This work investigates the relationships between partial melting, melt extraction, pluton growth and silicic volcanism in garnet-bearing felsic volcanic rocks that were extruded in the Iberian Pyrite Belt, at ca. 345 Ma. The garnets are of peritectic origin, displaying textural and chemical features of disequilibrium crystallization during partial melting reactions involving biotite at high temperatures (up to 870 °C) in the middle-lower crust. Major element composition suggests compositional equilibrium with the entrained and pinitized peritectic cordierite, but reveals some subsequent homogenization by diffusion. Trace element maps and spot analyses of garnet show, nonetheless, significant trace element variations, reflecting biotite and Y-REE-P-rich accessory phase breakdown during partial melting reactions. Peritectic garnet and cordierite growth resulted in the preservation of Th- and Y-rich prograde suprasolidus monazite, which constrains the timing of partial melting of the metapelitic protolith at ca. 356.8 ± 2.4 Ma. The zircon cargo further shows that a significant amount of zircon crystals from previously crystallized felsic melts were also remobilized and erupted. These were likely stored in an upper crustal pluton that grew episodically since ca. 390 Ma during voluminous melt generation periods within the middle to lower crust, which also resulted in voluminous volcanism. The geochemical trends of the felsic volcanic rocks reflect the entrainment of xenoliths of peritectic garnet, cordierite and feldspar, and as such, the garnet-bearing felsic volcanic rocks represent an erupted mixture of a lower-temperature (ca. 770 °C) silicic melt and autocrysts, and peritectic phases and zircon crystals from previously crystallized and stored felsic melts.

Efficient and stable self-powered PbSe photodetectors via doping-induced asymmetric Cr electrodes modulation of surface work function

Conventional PbSe infrared photodetectors typically demands a substantial external electric field, posing challenges in energy-constrained environments. Self-powered photodetectors present a promising avenue for addressing such electricity-related challenges. Nevertheless, the inherent limitations of symmetric Schottky contacts in metal-semiconductor-metal (MSM) photodetectors constrain their self-powered performance, resulting in opposing photocurrents. Constructing asymmetric MSM structures usually requires intricate design or sustained external fields. In this study, we propose a novel contact engineering strategy based on iodine doping to modulate surface work functions of PbSe film. Utilizing Cr electrodes, we achieve Ohmic contact on the iodine-doped top surface of PbSe film and Schottky contact on the as-grown bottom surface. This approach establishes a self-powered PbSe infrared photodetector with an asymmetric top-bottom MSM structure. We comprehensively investigate contact engineering by investigating surface chemical states, elemental variations, and surface work functions variation. Remarkably, the photodetector demonstrates an exceptional zero-bias detectivity of 1.13 × 109 Jones, with an extremely low dark current of 3.67 pA, high Ilight/Idark ratio exceeding 104, and extremely short response times of less than 1 ms, respectively. Our work introduces a new strategy for modifying the band structure, contributing to the fabrication of high-performance self-powered photodetectors.

XPS study on passivation behavior of naturally formed oxide on AlFeCuCrMg1.5 high-entropy alloy

High-entropy alloys have exceptional oxidation resistance due to their passive oxide film. In this study, photoelectron spectroscopy was used in a modern atomic-scale in situ initial oxidation analysis process to determine the oxidation behavior and elemental variation on its breakdown. Furthermore, the behavior of natural oxide formed on the AlFeCuCrMg1.5 HEA after the exposure of the alloy to the atmosphere for one hour, one day, and seven days was investigated in detail. Through a survey scan, the elements present on the oxidized surface were determined and quantified. Additionally, the seven-day-exposed HEA was depth-profiled and discovered drastic modifications in the alloy.

Analysis of Acoustic Elements in Northwest Pacific Ocean Based on Operational MODAS Data and Its Response to Kuroshio Seasonal Variation

This study utilized operational MODAS (Modular Ocean Data Assimilation System) data to analyze the seasonal variation of acoustic elements of Northwest Pacific Ocean (NWPO). Combining the seasonal variation of the Kuroshio, it further investigated the impact of the Kuroshio seasonal variation on acoustic properties. The results indicate that the distribution of acoustic elements have significant seasonal variation, with a strong correlation between sonic layer depth and mixed layer depth. The acoustic thermocline depth and thermocline depth show significant correlations in the whole area in winter and spring, while in the rest two seasons, it only occurs in low latitude, the southern part of South China Sea (SCS), and also the Kuroshio area.

Petrogenetic and geochemical constraints on ca. 1.89–1.88 Ga Bastanar mafic dyke swarm, Bastar craton, India: Insights into MORB- and OIB-type contributions and interactions with metasomatized subcontinental lithospheric mantle

The Bastar craton of the Indian Shield hosts several generations of mafic dyke swarms of various trends, compositions, and ages, which span from ca. 2.7 Ga to 1.42 Ga. This study focuses on geochemical attributes of the ca. 1.89–1.88 Ga NNW-trending Bastanar swarm, aiming to address a perceived discrepancy between its arc-like geochemistry and the influence of a heterogeneous mantle source. To resolve the intra-swarm geochemical variations, we conducted a comprehensive geochemical characterization and petrogenetic interpretation of the ca. 1.89–1.88 Ga Bastanar swarm. The samples from this swarm are categorized into two distinct groups, primarily based on their geochemical composition. The Group 1 samples exhibit higher TiO2 (1.06–1.86 wt%), (La/Yb)N (7.2–8.6), (Gd/Yb)N (2- 2.27), Nb (14.6–16.6 ppm), Th (1.23–3.03 ppm) and Zr (104–118.72 ppm) concentrations than the Group 2 samples. Furthermore, rare-earth element patterns and variations in high-field strength element contents in the Group 1 samples suggest derivation from a deeper, less depleted mantle source resembling an OIB/less MORB-type. This inference is further supported by higher TiO2/Yb, Zr/Nb, and Nb/Y ratios. In contrast, the Group 2 samples indicate derivation from a shallower, more MORB/less OIB-type depleted mantle source, as evidenced by lower TiO2/Yb, Zr/Nb, and Nb/Y ratios. Variations in Dy/Yb and Gd/Yb ratios confirm the involvement of variable mantle sources, implying the derivation of the Group 1 and 2 samples from garnet-rich and spinel-rich lherzolite mantle sources, respectively. The absence of consistent negative Nb-Ta-Ti anomalies in the Group 1 samples suggests an uncontaminated nature, ruling out any role of crustal contamination. On the other hand, the Group 2 samples display negative Nb-Ta-Ti anomalies with enriched LREE and LILE patterns, indicating the involvement of crustal components in their genesis. A trace-element modelling suggests that the ca. 1.89–1.88 Ga mafic dyke swarm exhibits significant intra-swarm variability, with at least two distinct source components contributing to its genesis – a depleted MORB-type and an enriched OIB-type mantle. Notably, the geochemical characteristics of the Group 2 samples suggest interaction with a metasomatized mantle source, possibly enriched by fluids from an earlier subducted slab. Geochemical evidence presented in this work supports Archean subduction-related processes for the crustal growth of the Bastar craton and highlight the enduring influence of a metasomatized sub-continental lithospheric mantle on subsequent magmatism over millions of years.

Cartographic evaluation of the risk of natural elements' deficiency in the soil cover provoking spatial variation of the endemic morbidity level (on example of thyroid morbidity among population of the Central Federal District, Russia).

The main goal of the study is to evaluate the contribution of the natural geochemical risk in the central part of the Eastern European Plain to the spatial distribution of human diseases provoked by the deficiency of biologically significant microelements (Co, Cu, and I) in the environment. The Central Federal District (CFD) of Russia, located in the Eastern European Plain is characterized by a deficiency of Co, Cu, and I in the environment (soils, local food). To access the risk of thyroid diseases associated with Co, Cu, and I content in soils of the CFD based on published data of trace elements concentrations and digital soil map we create maps of the elements variation in soil cover allowing to estimate their mean concentration in the regions. The obtained cartographic estimates are comparable with the previously published assessments and averaged study results at the regional level. Comparison with medical data on thyroid disease morbidity from 2013 to 2017 at the regional level showed a significant inverse correlation with the cartographic estimates of soil I and combined (Co + Cu + I) status with due consideration of soil structure (12 regions, except for those affected by technogenic radioiodine contamination and Moscow urbanized regions). The urban population suffered from thyroid diseases to a higher extent in comparison with the rural population, which corresponds to our previous estimates. The results confirmed the possibility of assessing the geochemical risk of endemic diseases based on geochemical soil maps and identifying the negative contribution of micronutrient deficiency in the environment to endemic morbidity in the population.

A chemodynamical analysis of bright metal-poor stars from the HESP-GOMPA survey – indications of a non-prevailing site for light r-process elements

ABSTRACT We present a comprehensive analysis of the detailed chemical abundances for a sample of 11 metal-poor, very metal-poor, and extremely metal-poor stars ([Fe/H] = −1.65 to [Fe/H]  = −3.0) as part of the HESP-GOMPA (Galactic survey Of Metal Poor stArs) survey. The abundance determinations encompass a range of elements, including C, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, and Ba, with a subset of the brighter objects allowing for the measurement of additional key elements. Notably, the abundance analysis of a relatively bright highly r-process-enhanced (r-II) star (SDSS J0019+3141) exhibits a predominantly main r-process signature and variations in the lighter r-process elements. Moreover, successful measurements of thorium in this star facilitate stellar age determinations. We find a consistent odd–even nucleosynthesis pattern in these stars, aligning with expectations for their respective metallicity levels, thus implicating Type II supernovae as potential progenitors. From the interplay between the light and heavy r-process elements, we infer a diminishing relative production of light r-process elements with increasing Type II supernova contributions, challenging the notion that Type II supernovae are the primary source of these light r-process elements in the early Milky Way. A chemodynamical analysis based on Gaia astrometric data and our derived abundances indicates that all but one of our program stars are likely to be of accreted origin. Additionally, our examination of α-poor stars underscores the occurrence of an early accretion event from a satellite on a prograde orbit, similar to that of the Galactic disc.