Search Results (1,346)

Background: Trace elements and heavy metals can provide valuable forensic information for individual identification, lifestyle reconstruction, and association with the scene or time of death and may also assist in linking objects to criminal activities. However, the lack of standardized guidelines and post-mortem reference values represents a significant limitation in forensic investigations. Methods: This review was conducted in accordance with the PRISMA statement. We performed a comprehensive literature study over the last ten years focusing on the analysis of trace elements and heavy metals in post-mortem tissues. Results: The search results from the databases yielded 247 records. The screening, according to PRISMA criteria, allowed us to select and include 19 articles. The results showed the need for standardized guidelines and reference values. Although post-mortem trace element analysis shows high potential for forensic applications, substantial methodological heterogeneity persists. Some studies have proposed preliminary reference values for cadmium (Cd) in kidneys and mercury (Hg) in hair but validated post-mortem reference ranges remain largely unavailable. Conclusions: The current literature demonstrates the forensic potential of trace element and heavy metals analysis including Cd, Hg, lead (Pb), Manganese (Mn), Aluminum (Al), Copper (Cu), Zinc (Zn), Iron (Fe), Thallium (Tl), Polonium (²¹⁰Po) but also underlines the urgent need for standardized protocols and validated post-mortem reference values to improve interpretability and reliability in forensic contexts. Full article

This article examines the interactions between Wang Yangming’s School of Mind and Daoist traditions, focusing on specific instances of contact, adaptation, and reinterpretation. Drawing on both historically attested events and later hagiographical narratives—treated here as cultural representations rather than literal biographies—the study traces how Wang encountered Daoist religious sites, imagery, and technical vocabulary over the course of his life. Particular attention is given to parallels between Wang’s use of concepts such as liangzhi (innate moral knowledge) and Daoist terms from inner alchemy, as well as his adaptation of practices like stillness-sitting (jingzuo) and the metaphor of “forming the sacred embryo” (jie shengtai). The analysis shows that these elements were selectively reframed within his own intellectual framework, often shifting their emphasis from physical cultivation or longevity to moral and practical self-cultivation. Such a reorientation may have something to do with the Jingming Sect 淨明道. By situating Wang’s reinterpretations within the broader religious and philosophical environment of early sixteenth-century China, the article contributes to a more nuanced understanding of cross-tradition engagement and the circulation of ideas between Confucianism and Daoism. Full article

The profound Phanerozoic destruction of the eastern North China Craton (NCC) is well documented, yet its mechanism remains debated due to limited constraints on thermal state and lithospheric thickness during the Early Cretaceous—the peak period of cratonic destruction. We address this gap through integrated geochemical analysis (major/trace elements, Sr-Nd-Pb isotopes, olivine chemistry) of Early Cretaceous (~125 Ma) Fangcheng basalts from Shandong. These basalts possess high MgO (8.14–11.31 wt%), Mg# (67.23–73.69), Ni (126–244 ppm), and Cr (342–526 ppm). Their trace elements show island arc basalt (IAB) affinities: enrichment in large-ion lithophile elements and depletion in high-field-strength elements, with negative Sr and Pb anomalies. Enriched Sr-Nd isotopic compositions [⁸⁷Sr/⁸⁶Sr(t) = 0.709426–0.709512; ε_Nd(t) = −12.60 to −13.10], unradiogenic ²⁰⁶Pb/²⁰⁴Pb(t) and ²⁰⁸Pb/²⁰⁴Pb(t) ratios (17.55–17.62 and 37.77–37.83, respectively), and slightly radiogenic ²⁰⁷Pb/²⁰⁴Pb(t) ratios (15.55–15.57) reflect an upper continental crustal signature. Covariations of major elements, Cr, Ni, and trace element ratios (Sr/Nd, Sc/La) with MgO indicate dominant olivine + pyroxene fractionation. High Ce/Pb ratios and lack of correlation between Ce/Pb or ε_Nd(t) and SiO₂ preclude significant crustal contamination. The combined isotopic signature and IAB-like trace element patterns support a lithospheric mantle source that was metasomatized by upper crustal material. Olivine phenocrysts exhibit variable Ni (1564–4786 ppm), Mn (903–2406 ppm), Fe/Mn (56.63–85.49), 10,000 × Zn/Fe (9.55–19.55), and Mn/Zn (7.07–14.79), defining fields indicative of melts from both peridotite and pyroxenite sources. High-MgO samples (>10 wt%) in the Grossular/Pyrope/Diopside/Enstatite diagram show a clinopyroxene, garnet, and olivine residue. Reconstructed primary melts yield formation pressures of 3.5–3.9 GPa (110–130 km depth) and temperatures of 1474–1526 °C, corresponding to ~60 mW/m² surface heat flow. This demonstrates retention of a ≥110–130 km thick lithosphere during peak destruction, arguing against delamination and supporting a thermo-mechanic erosion mechanism dominated by progressive convective thinning of the lithospheric base via asthenospheric flow. Our findings therefore provide crucial thermal and structural constraints essential for resolving the dynamics of cratonic lithosphere modification. Full article

Background and Objective: Thyroid cancer (TC) represents the most common group of endocrine tumors, and its incidence has increased over the last four decades. The imbalance of trace elements, such as zinc (Zn), has been investigated due to the thyroid’s sensitivity to these elements. Zn is essential for thyroid hormone action and may be involved in the pathogenesis of TC. This systematic review and meta-analysis aim to contribute to the discussion on the association between low serum Zn concentrations and the occurrence of TC. Materials and Methods: The search was carried out in the PubMed/MEDLINE, Scopus, Embase, LILACS and Web of Science databases, including observational studies published until December 2024. The primary outcome was low serum Zn concentration and the occurrence of TC. Three independent reviewers selected the studies and extracted the data from the original publications. The risk of bias was assessed using the Newcastle–Ottawa Quality Assessment Scale. Data analysis was performed using R software (V.4.3.1), and heterogeneity was calculated using the I² statistic, with results based on random effects models. Results: A total of 10 studies (n = 7 case–control and n = 3 cross-sectional) with sample sizes ranging from 44 to 294 individuals were included. The results indicated that serum Zn levels were not significantly lower in patients with TC compared with healthy controls (mean difference: −251.77; 95% confidence interval: −699.09, 195.54; I² = 100%, very low certainty). Conclusions: Further investigations, including rigorously designed observational studies with representative samples and improved control of potential confounding variables are indispensable. Full article

To unravel the link between agate geochemistry, host volcanic rocks, and ore-forming processes, this study integrated elemental correlation analysis, interaction interpretation, and interpretable machine learning (LightGBM-SHAP framework with SMOTE and 5-fold cross-validation) using 203 in-situ element datasets from 16 global deposits. The framework achieved 99.01% test accuracy and 97.4% independent prediction accuracy in discriminating host volcanic rock types. Key findings reveal divergence between statistical elemental correlations and geological interactions. Synergies reflect co-migration/co-precipitation, while antagonisms stem from source competition or precipitation inhibition, unraveling processes like stepwise crystallization. Rhyolite-hosted agates form via a “crust-derived magmatic hydrothermal fluid—medium-low salinity complexation—multi-stage precipitation” model, driven by high-silica fluids enriching Sb/Zn. Andesite-hosted agates follow a “contaminated fluid—hydrothermal alteration—precipitation window differentiation” model, controlled by crustal contamination. Basalt-hosted agates form through a “low-temperature hydrothermal fluid—basic alteration—progressive mineral decomposition” model, with meteoric water regulating Na-Zn relationships. Zn acts as a cross-lithology indicator, tracing crust-derived fluid processes in rhyolites, feldspar alteration intensity in andesites, and alteration timing in basalts. This work advances volcanic-agate genetic studies via “correlation—interaction—mineralization model” coupling, with future directions focusing on large-scale micro-area elemental analysis. Full article

The fragile ecological environment of the Qinghai–Tibet Plateau (QTP) is significantly affected by human activities. This study employed a self-organizing map (SOM) for cluster analysis and positive matrix factorization (PMF) to trace the source of potentially toxic elements (PTEs) in the surface water of rivers. The results revealed that the average concentration of PTEs in the rivers was generally low. However, at some sampling points, especially in areas near the Qarhan Salt Lake, the content of Cu, Hg, and Ni were high. The water quality index (WQI), contamination factor (CF), and modified contamination index (mCd) identified good water quality, while potential Ni in the Quanji and Golmud River basins were the primary contaminants of concern. The potential ecological risk index (PERI) showed a low ecological risk. The SOM yielded four clusters of water PTEs, including Hg, Cu-Ni, Pb-Cd-Zn, and As. PMF model further revealed PTE sources, with industrial sources (39.73%) as the primary anthropogenic factor, followed by natural weathering (33.44%), vehicle emissions (21.52%), and atmospheric deposition (5.31%). This study laid the foundation for the ecological monitoring of rivers on the QTP and provided a reference for balancing industrial development and ecological protection in Qarhan Salt Lake areas. Full article

The Dulong Sn-polymetallic deposit in Yunnan Province of southwestern China serves as a unique case study for unraveling the evolution of skarn systems and tin mineralization. Four distinct garnet types (Grt I to Grt IV) were classified based on petrographic observations. Compositional analysis reveals a progression from Grt I to Grt III, marked by increasing andradite components, and elevated tin concentrations, peaking at 5039 ppm. These trends suggest crystallization from Sn-enriched magmatic-hydrothermal fluids. In contrast, Grt IV garnet exhibits dominant almandine components and minimal tin content (<2 ppm). Its association with surrounding rocks (schist) further implies its metamorphic origin, distinct from the magmatic origin of the other garnet types. Combined with previously published sulfur and lead isotopic data, as well as trace element compositions of garnet, our study suggests that Laojunshan granites supply substantial ore-forming elements such as S, Pb, W, Sn, In, and Ga. In contrast, elements such as Sc, Y, and Ge are inferred to be predominantly derived from, or buffered by, the surrounding rocks. The geochemical evolution of the garnets highlights the critical role of redox fluctuations and fluid chemistry in controlling tin mineralization. Under neutral-pH fluid conditions, early-stage garnets incorporated significant tin. As the oxygen fugacity of the ore-forming fluid declined, cassiterite precipitation was triggered, leading to tin mineralization. This study reveals the interplay between fluid redox dynamics, garnet compositional changes, and mineral paragenesis in skarn-type tin deposits. Full article

The characteristics and evolution of fibrous calcite veins in organic-rich shales have gained significant attention due to the recent advancements in shale oil and gas exploration. However, the fibrous calcite veins in the Upper Permian Dalong Formation remain lacking in awareness. To investigate the formation and significance of bedding-parallel fibrous calcite veins in the Dalong Formation, we conducted an extensive study utilizing petrography, geochemistry, isotopic analysis, and fluid inclusion studies on outcrops of the Dalong Formation in South China. Our findings reveal that fibrous calcite veins predominantly develop in the middle section of the Dalong Formation, specifically within the transitional interval between siliceous and calcareous shales, characterized by symmetric, antitaxial fibrous calcite veins. The δ¹³C values of these veins exhibit a broad range (−4.53‰ to +3.39‰) and display a decreasing trend in the directions of fiber growth from the central part, indicating an increased contribution of organic carbon to the calcite veins. Additionally, a consistent increase in trace element concentrations from the central part toward the fiber growth directions suggests a singular fluid source in a relatively closed environment, while other samples exhibit no distinct pattern, possibly due to the mixing of fluids from multiple layers resulting from repeated opening and closing of bedding-parallel fractures in the shales. The notable difference in δEu between the fibers on either side of the median zone indicates that previously formed veins acted as barriers, impeding the mixing of fluids, with the variation in δEu reflecting the differing sedimentary properties of the surrounding rocks. The in situ U-Pb dating of fibrous calcite veins yields an absolute age of 211 ± 23 Ma, signifying formation during the Late Triassic, which correlates with a shale maturity of 1.0‰ to 1.25‰. This integrated study suggests that the geochemical records of fibrous calcite veins document the processes related to overpressure generation and the opening and healing of bedding-parallel fractures within the Dalong Formation. Full article

This study investigates the concentrations of essential and trace elements (Ni, Cu, Fe, Zn, Mn, and Al) in packaged ice cream samples collected from markets in Kırşehir province, located in Central Anatolia, Turkey, aiming to assess potential health risks associated with their consumption. Among the detected trace elements, Al (3.21–16.6 mg/kg) and Fe (2.03–24.0 mg/kg) had the highest concentrations, followed by Zn (0.56–3.00 mg/kg), Ni (0.84–4.84 mg/kg), Cu (1.15–3.46 mg/kg), and Mn (0.18–1.56 mg/kg). To explore the relationships between trace elements and identify possible contamination sources, chemometric approaches including principal component analysis, correlation matrices, and hierarchical cluster analysis (Ward’s method) were applied. Human health risk assessment was conducted by calculating Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), Hazard Index (HI), and Carcinogenic Risk (CR), with uncertainty evaluated through Monte Carlo Simulation (10,000 iterations). HI values above 1 in children and adults indicate that trace element exposure through ice cream consumption may pose a health risk. High Al-THQ and Ni-CR values in children may require stricter monitoring and regulatory measures in case of long-term and regular consumption. Full article

The present study provides a comprehensive characterization of soil elemental composition in the Nile Delta, Egypt. The soil samples were analyzed using Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), highly appropriative for the major element determination and Inductively Coupled Plasma Mass Spectrometry (ICP–MS), outstanding for the trace element analysis. A total of 55 elements were measured across 53 soil samples. A variety of statistical and analytical techniques, including both descriptive and inferential methods, were employed to assess the elemental composition of the soil. Bivariate and multivariate statistical analyses, discriminative ternary diagrams, ratio biplots, and unsupervised machine learning algorithms—such as Principal Component Analysis (PCA), t-Distributed Stochastic Neighbour Embedding (t-SNE), and Hierarchical Agglomerative Clustering (HAC)—were utilized to explore the geochemical similarities between elements in the soil. The application of t-SNE for soil geochemistry is still emerging and is characterized by the fact that it preserves the local distribution of elements and reveals non-linear relationships in geochemical research compared to PCA. Geochemical background levels were estimated using Bayesian inference, and the impact of outliers was analyzed. Pollution indices were subsequently calculated to assess potential contamination. The findings suggest that the studied areas do not exhibit significant pollution. Variations in background levels were primarily attributed to the presence of outliers. The clustering results from PCA and t-SNE were consistent in terms of accuracy and the number of identified groups. Four distinct groups were identified, with soil samples in each group sharing similar geochemical properties. While PCA is effective for linear data, t-SNE proved more suitable for nonlinear dimensionality reduction. These results provide valuable baseline data for future research on the studied areas and for evaluating their environmental situation. Full article

The development and use of urban spaces for food production is increasing in response to the search for healthier foods and contact with nature. These spaces can be created or built on materials of various types, which might contain potentially toxic elements (PTEs). This study focuses on the evaluation of soil fertility and contamination levels in urban and rural kitchen gardens in Lisbon, Portugal. Soils of twenty kitchen gardens (n_urban = 15; n_rural = 5) were sampled, and their physicochemical characteristics and the contents of PTEs in the total and available fractions were analyzed. The results were used to calculate contamination indices and associated ecological risk. The soils of the urban and rural kitchen gardens had a neutral pH, with the presence of carbonate forms, and moderate-to-high organic matter contents, although with a clear nutritional imbalance. Regarding PTEs, both urban and rural kitchen gardens soils showed elevated levels of certain elements (e.g., Cr, Ni, Cu), exceeding the maximum allowable values established by Portuguese regulations. However, the available fraction of these elements was generally low. Contamination indices ranged from mild to considerable in isolated cases, with no general multi-element contamination or ecological risk. This suggests that associated environmental and health risks are minimal, although periodic monitoring of kitchen gardens’ soil quality is necessary to ensure and maximize the health benefits. Full article

Identifying the mineral pigments used in the decoration of prehistoric pottery is a significant step for understanding the evolution of the technological practices over time. On the Balkan Peninsula during late prehistory, the techniques used for red and dark-colored decorations underwent a significant transformation. In the Early Neolithic period, pottery was often decorated with dark-toned paints, ranging from deep red to brown. However, this approach declined noticeably during the Chalcolithic period, when red pigment pseudo-incrustation became the predominant decorative method. This study aims to identify the mineral pigments used in red and dark decorations on Neolithic and Chalcolithic pottery from Bulgaria and to trace possible technological, regional, or chronological variations in their composition. A total of 34 ceramic sherds, decorated in shades from red to brown and black, were analyzed using two complementary spectroscopic techniques: laser-induced breakdown spectroscopy (LIBS) and Fourier-transform infrared spectroscopy (FTIR). LIBS data were further evaluated using principal component analysis (PCA) to classify materials based on elemental composition. The results indicate that red decorations are consistently composed of hematite and remain compositionally stable regardless of the region, time period, or application technique. In contrast, dark decorations contain various combinations of iron oxides (magnetite and hematite) and manganese oxides, often including barium-rich manganese compounds—potentially indicating pigment provenance. Additionally, the dark decorations display regional differences. Full article

Strontium, a key trace element regulating bone development and cardiovascular function, has seen growing research interest in its groundwater accumulation and resource potential. The unique geological structure of the northern Lushan Mountain slope provides an ideal setting to investigate strontium migration and enrichment. We systematically collected 21 groundwater samples and analyzed strontium occurrence characteristics and formation mechanisms using hydrochemical analysis, PHREEQC simulations, Gibbs diagrams, and cation exchange adsorption models. Analysis revealed that 71.4% of samples (15 groups) exceeded the GB 8537-2018 standard (≥0.4 mg/L), significantly higher than typical groundwater systems. Spatial distribution showed marked geological differentiation: average strontium concentration in Cambrian-Ordovician fractured-karst water reached 2.79 mg/L (range: 0.207–12.41 mg/L), 109.8% higher than in bedrock fissure water (1.33 mg/L). Structural control was evident, with samples near fault zones exhibiting generally higher concentrations than non-fault areas. Multivariate statistics indicated significant positive correlations between Sr²⁺ and TDS, Na⁺, Ca²⁺, and SO₄²⁻, suggesting synergistic enrichment mechanisms. Hydrogeochemical simulations confirmed that multiphase leaching of strontium-bearing silicate rocks provides the primary source, while rock weathering-driven ion exchange reactions constitute the key enrichment mechanism. This study elucidates the structural-lithological coupling-controlled hydrogeochemical cycle of strontium, providing theoretical support for delineating high-quality mineral water targets and developing health-beneficial geo-resources in the Lushan region. Full article

Rare earth elements (REEs) and trace elements, due to their relative stability during sedimentary processes, are effective geochemical proxies for sediment provenance. In the Dongdaohaizi Depression of the eastern Junggar Basin, the provenance of the Middle Jurassic Sangonghe Formation remains contentious. In this study, representative sandstone samples were systematically collected from all three members of the Sangonghe Formation in both the Dongdaohaizi Depression and its western margin. Through comprehensive petrographic and geochemical analyses, we obtained the following results. The Sangonghe Formation is primarily composed of feldspathic lithic sandstones, lithic sandstones, and minor lithic–feldspathic sandstones. The heavy mineral assemblage includes zircon, garnet, chromite, and rutile, suggesting source rocks of intermediate to acidic igneous, metamorphic, and mafic lithologies. The total REE contents range from 101.84 to 192.68 μg/g, with an average of 161.80 μg/g. The ∑LREE/∑HREE ratios vary from 6.59 to 13.25 (average 10.96), and the average δEu values are close to 1. The δCe value ranges from 1.09 to 1.13 (average 1.11). Trace element discrimination diagrams, including La-Th-Sc, Th-Co-Zr/10, Th-Sc-Zr/10, and La/Y-Sc/Cr ternary plots, indicate that most samples fall within the continental island arc domain, with a few plotting in the passive continental margin field. Comparison with potential surrounding source regions reveals dual provenances: an eastern source from the Kalamaili Mountains and a western source from the Zhayier Mountains. During the Early Jurassic, these two orogenic belts acted as distinct sediment sources. The Zhayier Mountains provided stronger input, with fluvial and tidal processes transporting sediments into the basin, establishing the primary subsidence center in the west of the depression. By the Middle Jurassic, continued thrusting of surrounding fold belts caused a migration of the lake center and the main depocenter to the western edge of the Dongdaohaizi Depression, while the former depocenter gradually diminished. Furthermore, sustained erosion and denudation of the Mosowan Uplift during the Early–Middle Jurassic reduced its function as a structural barrier, thereby promoting increased mixing between eastern and western sediment sources. The study not only refines existing paleogeographic models of the Junggar Basin, but also demonstrates the utility of REE–trace geochemistry in deciphering complex provenance systems in tectonically active basins. Full article

Elemental contents are effective fingerprints for Pu-erh tea’s geographical traceability, which is crucial for consumer protection and sustainable development. Region and processing methods are key factors influencing the tea’s elemental fingerprint. This study analyzed 28 elements in Pu-erh tea samples from three Yunnan production regions subjected to different processing stages in the year of 2023. The results show that significant regional differences were observed for 25 of the 28 elements. As, Li, Cu, Zn, and Cd contents vary significantly during processing. The contents of 27 elements (excluding Pb) are significantly influenced by the interaction between region and processing stage. Orthogonal partial least squares discriminant analysis (OPLS-DA) achieved good validation (Q² = 0.946) and identified 18 key factors, while the original and cross-validation correct classification rates were 100% and 98.6%, respectively. Crucially, the robustness of the model was confirmed with 100% accuracy through an independent validation set from tea samples in the harvest year of 2024. This study confirms that the elemental contents of Pu-erh tea are mainly influenced by region rather than processing stage, and elemental analysis can trace the geographical origin of Pu-erh effectively, even when mixed with a differently processed tea. Full article