Search Results (2,573)

The selective separation of chalcopyrite from pyritic ores represents a major industrial challenge due to inadvertent copper activation. This study systematically investigates the batch flotation kinetics of a complex sulfide ore (Draa Sfar North, Morocco) using a first-order kinetic model ($R^2>0.916$). The impacts of pulp pH, chemical depressants, and specialized collectors were evaluated to optimize the copper/iron selectivity index ($S{I}_{Cu/Fe}$). The results reveal a high-alkalinity paradox: At pH 11.0, chalcopyrite kinetics experience a severe passivation bottleneck ($K_{i,Cu}=0.1330 {\min }^{-1}$). At pH 11.5, selectivity collapses ($SI=2.64$) due to persistent iron sulfide floatability ($K_{i,Fe}=0.2066 {\min }^{-1}$). Conversely, natural pH ($\approx 6.0$) provides a superior baseline ($SI=3.32$), where 40 g/t sodium cyanide (NaCN) yielded a peak index of $S{I}_{Cu/Fe}=10.25$. As an eco-friendly substitute, sodium lignosulfonate (LSNa) achieved outstanding performance ($S{I}_{Cu/Fe}=5.30$), reducing iron kinetics to their lowest level ($K_{i,Fe}=0.0356 {\min }^{-1}$) via ferric–anionic complexation. Furthermore, Danafloat 271 secured the highest collector-driven selectivity ($S{I}_{Cu/Fe}=5.03$) by suppressing the iron matrix ($K_{i,Fe}=0.0306 {\min }^{-1}$) following Hard–Soft Acid–Base principles. This study clarifies specific aspects of selective copper–iron flotation, demonstrating that natural pH circuits with green depressants or selective collectors offer a sustainable alternative. Full article

Iron deficiency (ID) represents one of the most prevalent nutritional disorders worldwide, affecting approximately 1.2 billion individuals. Beyond its well-established hematological consequences, emerging evidence demonstrates that ID profoundly impacts endocrine function across multiple organ systems. Iron serves as an essential cofactor for numerous enzymes involved in hormone synthesis, metabolism, and signaling pathways. This comprehensive review examines the bidirectional relationships between iron deficiency and endocrine pathologies, including thyroid disorders (hypothyroidism, Hashimoto’s thyroiditis, thyroid peroxidase impairment), diabetes mellitus (types 1 and 2), obesity, Polyendocrine Metabolic Ovarian Syndrome (PMOS), male hypogonadism, adrenal insufficiency, growth hormone deficiency, pituitary dysfunction, and parathyroid disorders. We systematically analyze the molecular mechanisms linking iron metabolism to endocrine dysfunction, with particular emphasis on thyroid peroxidase activity, insulin secretion and sensitivity, hepcidin regulation, testosterone synthesis, and cortisol production. Furthermore, we critically evaluate the therapeutic potential of liposomal iron supplementation, a novel delivery system that offers superior bioavailability and gastrointestinal tolerability compared to conventional oral iron formulations. Randomized controlled trials demonstrate that liposomal iron achieves comparable efficacy to intravenous iron while significantly reducing adverse events. This review synthesizes current evidence to provide clinicians with a comprehensive understanding of iron-endocrine interactions and evidence-based recommendations for iron supplementation in endocrine disorders. Recognition of these complex relationships is essential for optimizing diagnostic and therapeutic approaches in patients with concurrent iron deficiency and endocrine dysfunction. Full article

The stele pavilion at the Jiezhou Guandi Temple in Shanxi Province is a significant Qing-dynasty architectural structure within one of China’s most renowned temple complexes dedicated to Guan Yu. However, its polychrome paintings have suffered severe deterioration due to prolonged weathering, and the composition, technological characteristics, and historical alterations of these paintings remain poorly understood. In this study, six polychrome pigment samples and one red oil-coating sample collected from different structural parts of the pavilion were systematically analyzed using laser Raman spectroscopy, scanning electron microscopy with energy-dispersive spectroscopy, X-ray diffraction, and pyrolysis-gas chromatography/mass spectrometry. The results show that the pigment layers primarily consist of mineral pigments including iron red, cinnabar, red lead, iron yellow, lavendulan, carbon black, and ultramarine, together with the organic pigment indigo. The oil coatings and polychrome paintings were restored in different periods. The initial oil coating, applied directly to the wood surface, has completely fallen off, whereas the later reapplication employed a single-layer ash ground with calcite aggregate and a binder of heat-bodied tung oil and rosin, indicating a simplified formula. The paint ground layer, dominated by kaolinite, contains pig blood, drying oil, and rosin, reflecting continuity with the Shanxi blood-based ground preparation tradition. These findings provide essential material evidence for conservation and offer a valuable case study for the technological history of Qing-dynasty regional architectural paintings in Shanxi. Full article

Spinal cord injury (SCI) is a devastating neurological condition characterized by irreversible primary damage followed by a complex secondary injury cascade involving oxidative stress, neuroinflammation, iron dysregulation, and regulated cell death. Among these mechanisms, ferroptosis, a distinct, iron-dependent form of regulated cell death driven by lipid peroxidation and redox imbalance, is increasingly recognized as a critical mediator of neurodegeneration after SCI. The miRNAs play essential roles in neural injury responses by modulating inflammation, oxidative stress, and cell-death pathways. Growing evidence indicates that miRNAs closely regulate ferroptosis-related signaling networks following SCI, influencing key molecular targets including iron metabolism, antioxidant defense systems, and lipid peroxidation pathways. Conversely, ferroptotic stress may alter miRNA expression profiles, suggesting a bidirectional regulatory relationship. In addition, ferritinophagy, a selective autophagy pathway degrading ferritin via nuclear receptor coactivator 4 (NCOA4), has emerged as an important yet underexplored regulator of intracellular iron homeostasis and ferroptosis susceptibility in SCI. This review systematically summarizes current evidence on the molecular mechanisms linking miRNAs and ferroptosis in SCI, highlights how miRNA-mediated regulation of ferroptosis contributes to neuronal death, glial responses, and impaired regeneration, and discusses emerging therapeutic strategies targeting this axis to promote neuroprotection and functional recovery. By integrating recent experimental findings, we aim to provide mechanistic insight and identify translational opportunities for miRNA- and ferroptosis-based interventions in SCI. Full article

Pharmaceutical pollutants have emerged as a critical class of aquatic micropollutants due to their continuous release, persistence, and potential impacts on ecosystems and human health. Conventional wastewater treatment systems are often insufficient to achieve complete removal, necessitating the development of advanced oxidation processes (AOPs), such as Fenton and Fenton-like systems. These processes rely on the generation of reactive oxygen species (ROS), including hydroxyl radicals (•OH), superoxide species, singlet oxygen, and, in some heterogeneous systems, high-valent iron-oxo intermediates, which collectively enable the degradation of structurally diverse and recalcitrant pharmaceutical compounds. Recent advances have highlighted the pivotal role of nanomaterials as catalysts in enhancing Fenton-based processes. Nanostructured catalysts, including iron-based nanoparticles (NPs), metal oxides, carbon-based materials, and bimetallic composites, offer high surface area, tunable redox properties, and improved electron transfer, leading to enhanced catalytic efficiency and mineralization rates. Importantly, the integration of green synthesis approaches using plant extracts, microorganisms, and biopolymers provides environmentally benign routes for nanomaterial fabrication while introducing functional surface groups that improve catalytic performance. Mechanistically, pharmaceutical degradation in Fenton systems involves complex pathways driven by multiple ROS species, including •OH, superoxide radicals, and singlet oxygen, leading to the formation of intermediate products and eventual mineralization. However, challenges such as NP aggregation, metal leaching, incomplete mineralization, and potential toxicity of intermediates remain critical considerations. This review critically evaluates the occurrence of pharmaceutical pollutants, the fundamentals of Fenton and Fenton-like processes, and the design and application of green-synthesized nanomaterials as efficient catalysts. It further explores degradation mechanisms, operational parameters, and sustainability considerations, highlighting future directions for scalable, environmentally responsible water treatment technologies. Full article

Although the mineralogical form of occurrence of critical metals is widely recognised as a key factor controlling their recovery during beneficiation, this relationship has rarely been verified directly on freshly mined ore and its primary beneficiation products from Central Asian polymetallic deposits. This raises the research question of how the mineralogical mode of occurrence of Bi, In, Cd, Co, Se, Te and Re governs their distribution between gravity and flotation products. Accordingly, the aim of this study was to establish how the mineralogical form of occurrence of these critical metals determines their distribution among gravity-concentration and flotation products, using ores from the Zhuantobe and Strezhanskoe deposits (Kazakhstan) as a case study. To this end, the mineralogical features and distribution patterns of critical metals during gravity and flotation beneficiation of polymetallic ores from these deposits were investigated by optical microscopy, X-ray diffraction, and SEM-EDS, while metal distribution among beneficiation products was determined by chemical analysis. Sphalerite, galena, pyrrhotite, and silver tellurides were identified as the main carriers of the critical metals, with bismuth occurring as an isomorphic admixture in sphalerite (3.69 wt.%) and galena (1.85 wt.%). During flotation, distribution was governed by mineralogical affinity: cadmium and indium were preferentially concentrated in the zinc concentrate (56.31% and 15.44% recovery, respectively), bismuth in the copper–lead concentrate (23.03%), and selenium and rhenium in the copper-bearing products (23.60% and 37.05%). Correlation analysis of the gravity-concentration products confirmed a close association of cadmium with sphalerite (R² = 0.9998), bismuth with galena and sphalerite (R² = 0.9674), and cobalt with iron-bearing sulfides (R² = 0.9144). These results demonstrate that the distribution of critical metals is governed primarily by their mineralogical form of occurrence rather than by bulk ore content, providing a basis for technologies for the complex processing of polymetallic ores. Full article

Iron beneficiation tailings from the Bayan Obo West Mine constitute a low-grade secondary rare-earth resource in which rare-earth minerals are finely disseminated and intricately intergrown with gangue. This study quantified the modes of occurrence of rare-earth minerals and assessed an integrated flowsheet comprising screening, magnetic separation, and flotation. The feed contained 1.32 wt.% rare-earth oxides (REOs), as determined by X-ray fluorescence spectrometry (XRF) and inductively coupled plasma optical emission spectrometry (ICP-OES). X-ray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), and automated mineralogy (AMICS) further showed that monazite and bastnäsite hosted 47.39% and 39.19% of the total REOs, respectively. Screening at 74 μm rejected 32.60% of the feed as a coarse fraction containing 0.65 wt.% REOs. Subsequent wet high-intensity magnetic separation reduced the mass entering flotation to 54.35% of the original feed while retaining 74.94% of the feed REOs and increasing the REO grade to 1.82 wt.%. Closed-circuit flotation with one rougher and three cleaner stages yielded a concentrate containing 51.99 wt.% REOs at an overall recovery of 52.38%. Rare-earth minerals accounted for 82.55 wt.% of the concentrate, including 41.65 wt.% monazite and 33.96 wt.% bastnäsite. This study thus demonstrated the feasibility of producing a high-grade rare-earth concentrate from the low-grade, fine-grained iron beneficiation tailings of the Bayan Obo West Mine characterized by complex mineral intergrowths, providing a practical basis for further rare-earth beneficiation and flowsheet optimization. Full article

The historical connection between art history and archaeology dates back to the origin of art history in emerging as a discipline from classical archaeology. The practices of both continue to diverge and intersect, rendering an ironic status for both as summarised in this contribution. Ecological approaches to archaeology are problematic, with the role of -scapes (land, sea, sky, etc.) and environments being weighted differently, depending on region, time period, and research questions. These are influenced by broader methodological approaches such as environmental determinism (processualism), traditional art history, field archaeology, and the emphasis of environmental studies on macro (-scape studies) and micro (archaeobotany and phytolith analysis) levels. Field archaeology is by necessity interdisciplinary, requiring different but complementary areas of expertise as discussed below. This contribution will elaborate on the relationship between archaeology, its intersecting disciplines and approaches, and the role of collaboration. It concludes with a brief case study summarising the relationship between trade, complex society, and scapes in the Late Bronze Age (ca. 1700–1200 BCE) Mediterranean and the possible role of climate change, piracy, and religion that caused its collapse in the 12th century BCE. Full article

The liver plays a central role in fatty acid (FA) metabolism, triacylglycerol synthesis, and energy homeostasis. The study aims to evaluate how a four-week dietary intervention with fish-based (EF), milk-based (EM), and standard diets (ES) affects relationships between mineral levels, FA profiles and indices, and oxidative stress parameters in female Wistar rats. Liver tissue samples were collected and analyzed for these variables. Post hoc analysis revealed significant differences in trace elements between the EM and EF and the EM and ES groups, and in toxic trace elements only between the EM and EF groups. Individual mineral differences were observed for calcium (Ca), iron (Fe), copper (Cu), zinc (Zn), arsenic (As), mercury (Hg), and lead (Pb), all showing large effect sizes (ηp² = 0.32–0.63). The strongest mineral–FA correlations occurred mainly in the ES group (15/25) and, to a lesser extent, in EF (9/25), involving 14 minerals, while only one mineral was significant in EM. Individual mineral correlations were most frequent in ES (13/25), followed by EF (8/25) and EM (4/25). Zn was the strongest predictor of malondialdehyde (MDA) in EF (90.6%), and Cu was the main determinant in ES (72.9%). We concluded that EM showed minimal interactions, limited to Fe and oleic acid, whereas EF and ES displayed multiple strong mineral–FA correlations, with ES exhibiting the most extensive and complex interaction network. Full article

Interpreting multispectral remote sensing data for hydrothermal alteration mapping remains challenging in complex mountainous metallogenic belts because dense pixel-level field labels are difficult to obtain and weak spectral responses are affected by lithological background, vegetation, snow/ice cover, and topographic shadow. This study proposes a principal component analysis (PCA)-guided weakly supervised workflow for mapping hydroxyl- and iron-oxide-related spectral anomalies in the Bulong–Maidan–Tuoyun gold–copper metallogenic belt, southwestern Tianshan, China, using Landsat 8 Operational Land Imager (OLI) imagery. PCA was used as a spectral prior to generate PCA-derived positive spectral anomaly samples for model training. A Residual-ECA Alteration Information Extraction (REA-AIE) model was developed to refine PCA-derived anomalies by learning local spectral–spatial features from multispectral image patches. Under the PCA-constrained random sample-level evaluation, REA-AIE achieved F1 scores of 95.90% and 97.09% for hydroxyl- and iron-oxide-related spectral anomalies, respectively; these values indicate agreement with PCA-derived pseudo-labels rather than spatially independent estimates of mapping performance. Petrography-constrained site-level assessment showed that REA-AIE-predicted spectral anomalies occurred within 90 m of 43 of the 53 altered sites, corresponding to a site-level recall of 81.13% and supporting their consistency with field-based geological evidence. Full article

This study explores the poetic formulation of justice and retribution in the Aqhat Epic. ˀIlu, the supreme god of Ugarit, designates the goddess ˁAnatu “impious in heart,” yet he neither prevents her murder of ˀAqhatu nor punishes her overtly. The narrative contains no judicial scene and no central governing deity who assumes the role of explicit divine adjudicator. Nevertheless, one may ask whether the story is shaped by a guiding mechanism of justice, comparable to certain biblical models of retribution, and what conception of retribution emerges from it, illuminating the relationship between gods and humans. The article highlights multiple instances showing that the narrative weaves a complex web linking transgression and consequence, in which acts of violence, desire, and rebellion give rise to corresponding consequences. These consequences manifest not only as visible punishments—such as the loss of the bow, the breaking of wings, and the curses upon implicated agents—but also in subtle reversals and ironic patterns accessible primarily to the audience. The moral order is neither absent nor declarative; rather, it is mediated through poetic formulations. Retribution unfolds on two interrelated levels: through overt narrative events and through a covert rhetorical structure that forges connections by means of repetition, key words, wordplay, and thematic symmetry. The study employs contextual close reading, supplemented by comments on the character roles. The conclusion reached is that the mechanism of measure-for-measure functions in the Aqhat Epic as a structuring narrative device, and that a sense of justice emerges through the convergence of human and divine agency. Full article

Effective iron removal from highly acidic leachates without neutralizer addition is a long-standing challenge in hydrometallurgy. For Cu-Co-bearing pyrite cinder, we demonstrate that a cyclic leaching process achieves this outcome. Operating entirely without neutralizers, the process consumed 96% of residual acid, enriched Cu and Co 4.76- and 3.88-fold, and removed 48.2% of iron, all while maintaining pH below 1.5 across four closed-loop cycles. Thermodynamic analysis reveals that Fe³⁺-${\mathrm{SO}}_4^{2-}$ complexation suppresses free Fe³⁺ to approximately 10⁻⁸ mol/L, ruling out conventional hydrolytic precipitation and directing precipitation towards schwertmannite-type basic ferric sulfate (Fe₈O₈(OH)₆SO₄). The formation of this sulfate-bearing Fe precipitate is consistent with the thermodynamic analysis, the iron mass balance, and a 176% increase in solid-phase sulfur. This neutralizer-free strategy offers a sustainable paradigm for recovering critical metals from iron-rich secondary resources. Full article

Germanium is a critical rare-dispersed metal with irreplaceable applications in infrared optics, fiber-optic communications, and semiconductor industries, making its efficient recovery from secondary resources of great strategic importance. This study investigates the selective recovery of germanium from complex zinc smelting leachates using a novel hydroxamic acid extractant, BGYW, in synergistic combination with P204. The feed solution contained approximately 360 mg/L Ge, 10,790 mg/L Fe²⁺, and 98,530 mg/L Zn, representing a highly complex matrix. Continuous counter-current extraction was performed in a 30-stage miniature mixer-settler. Under optimized conditions of 10% BGYW + 5% P204 in white oil, an O/A ratio of 1:1, and 8 mol/L NH₄F as strippant, the single-stage germanium extraction efficiency reached 99.4%. Over 16 consecutive cycles, the extraction system maintained stable performance with average germanium extraction above 99%. A 3-stage scrubbing section using 50 g/L H₂SO₄ effectively removed co-extracted Zn, Cu, and Al impurities. Iron co-extraction, a major challenge, was successfully mitigated through a 2–3 stage iron scrubbing step using a chloride-containing scrubbing solution, which reduced the iron concentration in the strip liquor from approximately 600 mg/L to below 4 mg/L, and decreased the Fe/Ge mass ratio from 0.197 to below 0.01. The overall germanium recovery across the entire 30-stage continuous process reached 98.82%, and the dissolution loss of BGYW in the aqueous phase was reduced by over 85% compared to the conventional YW100 extractant. Third-phase formation caused by residual organic flocculants from the leaching step was eliminated through enhanced pre-treatment, while ferric fluoride precipitation in the stripping section was resolved by incorporating the iron scrubbing stage. This study demonstrates that the BGYW-P204 extraction system with the integrated iron scrubbing step offers an efficient, stable, and industrially viable approach for germanium recovery from zinc smelting leachates, providing a practical solution to the long-standing challenge of germanium–iron separation and contributing to the sustainable supply of this critical metal. Full article

Selective recovery of gold from cyanide leach liquors is hindered by the co-dissolution of iron minerals that generate ferrocyanide complexes which strongly compete with [Au(CN)₂]⁻ at ion-exchange sorbents. Here, we investigate mixed-bed interpolymer systems (IPS) composed of a strong-acid sulfonated polystyrene–divinylbenzene cation exchanger (TC007, Na⁺ form) and a strong-base quaternary ammonium anion exchanger (AV-17-8, Cl⁻ form) as a charge-selective platform for gold cyanide recovery. IPS compositions spanning cation-to-anion molar ratios from 6:0 to 0:6 were evaluated in batch contact with binary model solutions containing 30 mg L⁻¹ each of [Au(CN)₂]⁻ and [Fe(CN)₆]⁴⁻ at pH 10 and 25 °C. The optimal 1:5 IPS achieved an [Au(CN)₂]⁻ extraction degree of 79.88% and a selectivity coefficient β = D_Au/D_Fe = 4.95 at 48 h, whereas the pure AV-17-8 anion exchanger (0:6) reached only 37.55% Au extraction at 48 h, following an atypical delayed-uptake kinetic profile rather than the rapid, near-quantitative capture expected of an unmodified strong-base resin. Sorption kinetics were best described by a pseudo-second-order model (R² = 0.9992), confirming ion exchange at quaternary ammonium sites as the dominant rate-controlling step, with a ~30-fold increase in k₂ for [Au(CN)₂]⁻ in the 1:5 IPS relative to AV-17-8 alone. FTIR spectroscopy and TGA-DSC revealed the incorporation of metal cyanide complexes into the IPS matrix, with diagnostic C≡N stretching bands at 2108.7 and 2034.1 cm⁻¹ and an additional thermal event at 200–280 °C. These findings establish compositionally tunable IPS based on commercially available resins as a charge-selective sorbent platform demonstrating a capacity to regenerate under single-cycle elution conditions for gold cyanide recovery from ferrocyanide-containing process streams while highlighting the need for further evaluation under industrial Fe:Au ratios. Full article

Ovotransferrin (OvoTf) is an iron-binding glycoprotein of avian innate immunity with antimicrobial activity, but its antifungal mechanism remains incompletely understood. We examined the candidacidal activity of OvoTf and two derived γ-core-containing peptides, kaliocin-3 (Kal-3) and kaliocin-4 (Kal-4), against Candida albicans. All three agents reduced fungal viability in a concentration-dependent manner, with minimal propidium iodide uptake, indicating a predominantly non-permeabilizing mechanism. Their activity was attenuated by extracellular Na⁺ and K⁺, whereas isoosmotic sorbitol did not confer protection. OvoTf induced partial K⁺ release, and tetraethylammonium increased cell survival. Inhibition of mitochondrial complex I or ATP synthase also reduced susceptibility, although none of the agents detectably suppressed oxygen consumption under the conditions tested. OvoTf, Kal-3, and Kal-4 caused plasma membrane depolarization, ATP accumulation, and impaired glucose-induced proton extrusion. This phenotype is consistent with disruption of Pma1-dependent proton and ion homeostasis, with mitochondrial bioenergetic activity contributing as a downstream requirement rather than constituting the primary target. Neither peptide caused detectable hemolysis; Kal-4 had minimal effects on mammalian cell metabolic viability, whereas Kal-3 reduced MCF-7 metabolic viability at higher concentrations. The activity of γ-core regions in both OvoTf lobes supports their further study as templates for mechanism-guided antifungal design. Full article