Search Results (669)

This study investigates the metasedimentary sequences of terrigenous–carbonate Sakar-type Triassic (TCSTT) and Sakar-type Triassic (STT) in the Sakar Unit, southeastern Bulgaria. Both share lithological similarities (alternation of carbonate–silicate schists, mica schists, marbles, and impure marbles) and are affected by post-Triassic metamorphism, but with differences in metamorphic grade and partly in the variation of potential sources of the sedimentary material. STT shows a higher metamorphic grade (lower amphibolite facies) when compared to TCSTT (lower greenschist facies). Petrographic observations and geochemical analyses indicate protoliths composed of arkosic sandstones, shales, and limestones derived from a quartz-dominated source with minor contributions from intermediate magmatic sources. The U-Pb geochronology of the detrital zircons reveals a dominant Carboniferous age complemented by an Early Ordovician age, which is consistent with the presence of Carboniferous–Permian igneous rocks in the basement. The presence of Early Paleozoic and Cambrian–Neoproterozoic zircons in the detrital zircon populations suggests that older rocks of the basement of the Sakar Unit and the Srednogorie Zone are also sources of the sedimentary material. Based on the immobile trace element content and discrimination diagrams, the siliciclastic component originates from rocks formed in a continental-arc setting. REE patterns indicate a negative Eu anomaly inherited from granitic-source rocks. Full article

MICA/B molecules (MICs) are stress-induced molecules expressed by infected and tumor cells. Their expression also characterizes trophoblast cells. Cytotoxic lymphocytes, including natural killer (NK) cells, express the NKG2D receptor, aiding them in the recognition and destruction of target cells that present MICs. To evade destruction, target cells employ various defense mechanisms, including the secretion of soluble forms of MICs. Choriocarcinoma JEG-3 cells and NK-92 cells were used to assess the expression of MICs and NKG2D. The cytotoxicity of NK-92 cells against JEG-3 cells in the presence of trichostatin A (TSA), anti-MICA/B antibodies (anti-MICA/B), and recombinant MIC proteins (rMICA/B) was evaluated. JEG-3 cells and NK-92 cells express MICs. Additionally, NK-92 cells exhibit high levels of NKG2D receptor expression. TSA treatment reduced the surface expression of MICs on choriocarcinoma cells, and was also associated with the release of soluble MICB. However, the TSA-induced decrease in MIC expression by choriocarcinoma cells did not protect them from the cytotoxic effects of NK cells. Only the activation of NK cells by IL-12 resulted in a decline in susceptibility of TSA-treated choriocarcinoma cells to NK cell-mediated cytotoxicity. Thus, NK cells activated by IL-12 lose their ability to effectively kill TSA-treated choriocarcinoma cells through the MIC-mediated mechanisms. Full article

Ten ukiyo-e woodblock prints from the collection of the Museo delle Culture in Lugano (Switzerland) were analyzed to identify the materials used in their production. These Japanese artworks were traditionally created with colors derived from minerals and plants, mixed with diluted animal glue and applied to paper using wooden matrices. Due to their fragility, non-invasive external reflection infrared spectroscopy and imaging analysis were employed. Spectral data were compared with reference samples of Japanese pigments and existing literature, reflecting the growing interest in the characterization of ukiyo-e prints. Within the limits of the non-invasive approach, several colorants were identified, including akane (madder), suo (sappanwood), yamahaji (Japanese sumac), kariyasu (Eulalia), and kio (orpiment), along with a proteinaceous binding medium. The extensive use of bero-ai (Prussian blue), applied both as a pure pigment and in mixtures, was confirmed. Notably, mica was detected in the background of one print, providing the first analytical evidence of the kirazuri decorative technique, which produces a sparkling, silver-like effect. Ultraviolet-induced fluorescence imaging further contributed to the assessment of conservation status, revealing faded decorative motifs and signs of previous water damage. Full article

This study investigates the influence of hybrid filler systems comprising carbon black (CB), mica, and surface-modified mica (SM) on the properties of ethylene–propylene–diene monomer (EPDM)/butadiene rubber (PB) composites. To reduce the environmental issues associated with CB, mica was incorporated as a partial substitute, and its compatibility with the rubber matrix was enhanced through surface modification using ureidopropyltrimethoxysilane (URE). The composites with hybrid filler systems and surface modification were evaluated in terms of curing behavior, crosslink density, mechanical and elastic properties, and dynamic viscoelasticity. Rheological analysis revealed that high mica loadings delayed vulcanization due to reduced thermal conductivity and accelerator adsorption, whereas SM composites maintained comparable curing performance. Swelling tests showed a reduction in crosslink density with increased unmodified mica content, while SM-filled samples improved the network density, confirming enhanced interfacial interaction. Mechanical testing demonstrated that the rubber compounds containing SM exhibited average improvements of 17% in tensile strength and 20% in toughness. In particular, the CB20/SM10 formulation achieved a well-balanced enhancement in tensile strength, elongation at break, and toughness, surpassing the performance of the CB-only system. Furthermore, rebound resilience and Tan δ analyses showed that low SM content reduced energy dissipation and improved elasticity, whereas excessive filler loadings led to increased hysteresis. The compression set results supported the thermal stability and recovery capacity of the SM-containing systems. Overall, the results demonstrated that the hybrid filler system incorporating URE-modified mica significantly enhanced filler dispersion and rubber–filler interaction, offering a sustainable and high-performance solution for elastomer composite applications. Full article

Container production of landscape plants requires reliably consistent and affordable substrates with properties suitable for a wide range of species. Native plant production often requires additional considerations when determining ideal substrates for species found in precise ecosystems. Thus, the introduction of novel native species, such as garberia [Garberia heterophylla (W. Bartram) Merrill & F. Harper] requires research insight into discerning which type of substrate provides the greatest plant quality in the least amount of time. In this greenhouse study, garberia was container-grown for six months in five substrates. These included two different pine bark-based media (Atlas 3000 and ‘Native mix’) typically used for native plant production, a commercial standard of peat-based medium (ProMix BX), and compost-based medium (COMANDscape) by itself or at a 1:1 compost/native mix ratio. All substrates varied from each other in terms of pH and electroconductivity (EC), with ProMix BX having the most acidic pH (5.3) and COMANDscape having the highest EC (5.2 dS/m). The ProMix BX had the greatest water-holding capacity, while the Atlas 3000 had the greatest bulk and particle densities. After six months, plant heights and widths were similar between treatments. The ProMix BX yielded the greatest shoot and root dry matter values and well-developed root systems that held the substrate the best. Plants grown in ProMix BX or COMANDscape had the greatest SPAD values and very good to excellent shoot visual quality ratings, compared to other substrates evaluated. While garberia was found to be a slow-growing species regardless of substrate, these results demonstrate its tolerance of diverse substrates that are non-characteristic of the soil where it thrives naturally. This knowledge can be useful for nursery practitioners; ultimately contributing to expanded production and the widened use of garberia in landscapes. Full article

Mica is a naturally layered material recognized for its superior insulation and exceptional barrier properties; however, it is prone to agglomeration, and its compatibility with resin remains to be resolved. In this work, phosphate butynediol ethoxylate (PBEO), synthesized by the reaction of a commercial corrosion inhibitor, butynediol ethoxylate, with phosphorus pentoxide, was employed to modify mica nanosheets (MNs), as evidenced by FTIR, Raman, and XPS. The obtained MN@PBEO demonstrated improved water dispersibility and enhanced compatibility with acrylic latex. EIS measurements revealed that the impedance (|Z|_0.01Hz) for the waterborne acrylic coating with 0.5 wt% MN@PBEO was approximately an order of magnitude greater than that of the pure waterborne acrylic coating after 28 days of immersion in a 3.5 wt% NaCl solution. Additionally, compared to the pure waterborne acrylic coating, the 0.5 wt% MN@PBEO/acrylic nanocomposite coating on Q235 carbon steel exhibited a water diffusion coefficient that was roughly ten times lower, demonstrating substantially enhanced corrosion protection, attributable to its superior barrier properties. Full article

The copper oxide ore in Zambia exhibits complex mineralogical characteristics, with copper primarily occurring in mica. The local hydrometallurgical plant employs heating–agitation acid leaching, which is hindered by a low leaching rate and prolonged leaching period, resulting in high energy consumption. To enhance the copper leaching efficiency, a systematic study was conducted on the use of organic cationic surfactants to enhance the leaching of the copper oxide ore. The results indicated that the primary copper-bearing mineral in the raw ore is cupriferous biotite, which is the reason for the difficulty in leaching. Under optimal conditions: a sulfuric acid dosage of 45 kg/t, a CTAB dosage of 75 g/t, a leaching temperature of 65 °C, a liquid-to-solid ratio of 2:1, and a leaching time of 120 min, the copper leaching rate reached 78.32%. Compared to the optimal result of regular heating–agitation acid leaching, this approach increased the copper leaching rate by 3.06%, reduced the leaching time by 80 min, and lowered leaching energy consumption without destroying the structure of cupriferous biotite. Mechanistic studies show that organic cations in CTAB neutralize excess anions, thereby weakening the electrostatic Coulomb forces between the interlayer cations and the hexagonal structure. This increases the interlayer spacing of biotite, facilitating the entry of H⁺ from sulfuric acid into the interlayer. The H⁺ then reacts with the copper in the biotite, enhancing the copper leaching rate and reducing leaching time. Because CTAB has high degradability, it will not cause persistent pollution to the environment. The use of CTAB as a leaching aid can reduce the energy consumption of heating–agitation acid leaching and reduce the heating cost per ton of ore by USD 6.11–9.36. Full article

Carbon nanotube field-effect transistors (CNT FETs) are considered strong candidates for next-generation flexible electronics due to their excellent carrier mobility and mechanical flexibility. However, the fabrication of CNT FETs on conventional flexible substrates such as PI or PET is often limited by surface roughness, chemical incompatibility, and poor mechanical robustness, resulting in degraded device performance. In this study, we report the fabrication of buried-gate CNT FETs incorporating Hf_0.5Zr_0.5O₂ as the gate dielectric on mica substrates, which offer high surface flatness, low defect density, and superior mechanical durability. The fabricated devices exhibit outstanding electrical characteristics, including a field-effect mobility of 38.4 cm²/V·s, a subthreshold swing of 93 mV/dec, and a transconductance of 14.2 μS. These results demonstrate the excellent mechanical stability and reliable electrical performance of the proposed devices under bending stress, highlighting their suitability for mechanically demanding flexible electronics applications. Full article

The increasing shortage of drinking water, driven by reduced rainfall and the intensification of industrial and agricultural activities, has raised justified concerns about the quantity and quality of available water resources. These sectors not only demand high water consumption but also discharge large amounts of toxic substances such as organic matter, metal ions and inorganic anions, posing risks to both public health and the environment. This study evaluated the effectiveness of clay-based nanomaterials in the treatment of contaminated industrial wastewater from the mining sector. The materials tested included montmorillonite, high-loading expandable synthetic mica, and their organically functionalized forms (MMT, Mica-Na-4, C18-MMT, and C18-Mica-4). The experimental results show that these clays had minimal impact on the pH of the water, while a notable decrease in the chemical oxygen demand (COD) was observed. Ion chromatography indicated an increase in nitrogen and sulfur compounds with higher oxidation states. Inductively coupled plasma analysis revealed a significant reduction in the calcium concentration and an increase in the sodium concentration, likely due to cation exchange mechanisms. However, the removal of copper and iron was ineffective, possibly due to competitive interactions with other cations in the solution. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) confirmed the structural modifications and interlayer spacing changes in the clay materials upon exposure to contaminated water. These findings demonstrate the potential of clay minerals as effective and low-cost materials for the remediation of industrial wastewater. Full article

This study explores the magmatic and hydrothermal evolution of porphyry–skarn–transitional Cu-Mo-W-Au systems within the Nilüfer Mineralization Complex (NMC), located in the westernmost segment of the Eocene Tavşanlı Metallogenic Belt, NW Türkiye. Through integration of field data, whole-rock geochemistry, Re–Os molybdenite dating, and amphibole–biotite mineral chemistry, the petrogenetic controls on mineralization across four spatially associated mineralized regions (Kirazgedik, Güneybudaklar, Kozbudaklar, and Delice) were examined. The earliest and thermally most distinct phase is represented by the Kirazgedik porphyry system, characterized by high temperature (~930 °C), oxidized quartz monzodioritic intrusions emplaced at ~2.7 kbar. Rising fO₂ and volatile enrichment during magma ascent facilitated structurally focused Cu-Mo mineralization. At Güneybudaklar, Re–Os geochronology yields an age of ~49.9 Ma, linking Mo- and W-rich mineralization to a transitional porphyry–skarn environment developed under moderately oxidized (ΔFMQ + 1.8 to +0.5) and hydrous (up to 7 wt.% H₂O) magmatic conditions. Kozbudaklar represents a more reduced, volatile-poor skarn system, leading to Mo-enriched scheelite mineralization typical of late-stage W-skarns. The Delice system, developed at the contact of felsic cupolas and carbonates, records the broadest range of redox and fluid compositions. Mixed oxidized–reduced fluid signatures and intense fluid–rock interaction reflect complex, multistage fluid evolution involving both magmatic and external inputs. Geochemical and mineralogical trends—from increasing silica and Rb to decreasing Sr and V—trace a systematic evolution from mantle-derived to felsic, volatile-rich magmas. Structurally, mineralization is controlled by oblique fault zones that localize magma emplacement and hydrothermal flow. These findings support a unified genetic model in which porphyry and skarn mineralization styles evolved continuously from multiphase magmatic systems during syn-to-post-subduction processes, offering implications for exploration models in the Western Tethyan domain. Full article

Red sandstones of the Cambrian age are globally distributed and represent an important sedimentation phase during this critical time interval. Their sedimentology and geochemistry can provide key information about the sedimentation style, paleoclimatic conditions, and weathering trends during the Cambrian. In the Salt Range of Pakistan, the Khewra Sandstone constitutes the Lower Cambrian strata and consists of red–maroon sandstones with minor siltstone and shale in the basal part. Cross-bedding, graded bedding, ripple marks, parallel laminations, load casts, ball and pillows, desiccation cracks, and bioturbation are the common sedimentary features of the formation. The sandstones are fine to medium to coarse-grained with subangular to subrounded morphology and display an overall coarsening upward trend. Petrographic analysis indicates that the sandstones are sub-arkose and sub-lithic arenites, and dolomite and calcite are common cementing materials. X-ray Diffraction (XRD) analysis indicates that the main minerals in the formation are quartz, feldspars, kaolinite, illite, mica, hematite, dolomite, and calcite. Geochemical analysis indicates that SiO₂ is the major component at a range of 53.3 to 88% (averaging 70.4%), Al₂O₃ ranges from 3.1 to 19.2% (averaging 9.2%), CaO ranges from 0.4 to 25.3% (averaging 7.4%), K₂O ranges from 1.2 to 7.4% (averaging 4.8%), MgO ranges from 0.2 to 7.4% (averaging 3.5%), and Na₂O ranges from 0.1 to 0.9% (averaging 0.4%), respectively. The results of the combined proxies indicate that the sedimentation occurred in fluvial–deltaic settings under overall arid to semi-arid paleoclimatic conditions with poor to moderate chemical weathering. The Khewra Sandstone represents the red Cambrian sandstones on the NW Indian Plate margin of Gondwana and can be correlated with contemporaneous red sandstones in the USA, Europe, Africa, Iran, and Turkey (Türkiye). Full article

High-purity quartz (HPQ), an indispensable industrial mineral, serves as a critical raw material for advanced technology sectors. Derived from natural quartz precursors through processing, HPQ preparation efficiency fundamentally depends on raw material selection. Two pegmatite samples (muscovite pegmatite and two-mica pegmatite) sampled from the eastern sector of the North Qinling Orogenic Belt were investigated through a suite of analytical techniques, as well as processing and purification, to evaluate their potential as raw materials for high-purity quartz. Muscovite pegmatite is predominantly composed of quartz, plagioclase, K-feldspar, muscovite, and garnet, with accessory phases including limonite and kaolinite. However, in addition to quartz, plagioclase, K-feldspar, muscovite, garnet, and limonite, two-mica pegmatite contains minerals such as biotite and calcite. The fluid inclusions in both muscovite and two-mica pegmatite quartz are small, but the former has fewer fluid inclusions. Compared with muscovite pegmatite, surface discontinuity (i.e., cracks, pits, cavities) development is more pronounced in two-mica pegmatite purified quartz, which may be related to its high content of fluid inclusions. Following purification, the total concentration of trace elements decreased significantly. However, the concentrations of Al and Ti appeared to remain the same. Titanium enrichment in purified two-mica pegmatite quartz likely derives from biotite, while Na and Ca concentrations may be related to fluid inclusions or microscopic mineral inclusions. The trace element content (27.69 ppm) in muscovite pegmatite is lower than that (45.28 ppm) of two-mica pegmatite, we thus suggest that muscovite pegmatite quartz is more likely to have the potential to produce high-purity quartz. Full article

Soil contamination with toxic inorganic elements poses a major challenge to rice cultivation, affecting plant physiology, yield, and grain safety. While natural variation in tolerance exists among rice genotypes and related species, recent advances in genomics, breeding, and biotechnology offer new opportunities to enhance adaptation. This review synthesizes the current knowledge on the physiological effects of toxic elements and explores strategies to improve tolerance, from harnessing genetic diversity to genome editing and transgenic approaches. Attention is also paid to the role of microbiota in mitigating toxicity and reducing translocation to seeds, highlighting emerging solutions for sustainable rice production in contaminated environments. Full article

This study investigates the impact of mineralogical and petrographic characteristics on the mechanical behavior of granitic and mafic rocks from the Shuangjiangkou (Sichuan Province) and Damiao complexes (Hebei Province) in China. The research methodology combined petrographic investigation, comprising optical microscopy and Scanning Electron Microscopy–Energy-Dispersive X-ray Spectroscopy (SEM-EDS) methods, with methodical geotechnical characterization to establish quantitative relationships between mineralogical composition and engineering properties. The petrographic studies revealed three lithologic groups: fine-to-medium-grained Shuangjiangkou granite (45%–60% feldspar, 27%–35% quartz, 10%–15% mica), plagioclase-rich anorthosite (more than 90% of plagioclase), and intermediate mangerite (40%–50% of plagioclase, 25%–35% of perthite). The uniaxial compressive strength tests showed great variations: granite (127.53 ± 15.07 MPa), anorthosite (167.81 ± 23.45 MPa), and mangerite (205.12 ± 23.87 MPa). Physical properties demonstrated inverse correlations between mechanical strength and both water absorption (granite: 0.25%–0.42%; anorthosite: 0.07%–0.44%; mangerite: 0.10%–0.25%) and apparent porosity (granite: 0.75%–0.92%; anorthosite: 0.20%–1.20%; mangerite: 0.29%–0.69%), with positive correlations to specific gravity (granite: 1.88–3.03; anorthosite: 2.67–2.90; mangerite: 2.43–2.99). Critical petrographic features controlling mechanical behavior include the following: (1) mica content in granite creating anisotropic properties, (2) extensive feldspar alteration through sericitization increasing microporosity and reducing intergranular cohesion, (3) plagioclase micro-fracturing and alteration to clinozoisite–sericite assemblages in anorthosite creating weakness networks, and (4) mangerite’s superior composition of >95% hard minerals with minimal sheet mineral content and limited alteration. Failure mode analysis indicated distinct patterns: granite experiencing shear-dominated failure (30–45° diagonal planes), anorthosite demonstrated tensile fracturing with vertical splitting, and mangerite showed catastrophic brittle failure with extensive fracture networks. These findings provide quantitative frameworks that relate petrographic features to engineering behavior, offering valuable insights for rock mass assessment and engineering design in similar crystalline rock terrains. Full article

Background: Tumor-associated macrophages (TAMs) play a crucial role in the tumor microenvironment (TME), and the metabolic activities of both tumor cells and TAMs have an impact on the TME. Moreover, the expression of MICA in tumor cells is closely associated with immune cells in hepatocellular carcinoma (HCC). However, it remains unclear whether MICA expression correlates with TAMs and influences the switch in macrophage phenotype by mediating metabolic alterations. Methods: Various biostatistical tools, qPCR, and IHC staining experiments were utilized to analyze data from The Cancer Genome Atlas (TCGA) and collected HCC tumor tissues. Single-cell RNA sequencing (scRNA-seq) analyses and a co-culture model of HCC cells with macrophages were performed to validate the findings from the biostatistical analyses. Results: Through the intersection of differentially expressed genes (DEGs), metabolism-related genes (MRGs), and co-expression genes (CEGs) with MICA in HCC, the EHHADH gene was identified. Gene set enrichment analyses were conducted to further confirm the role of EHHADH. EHHADH expression is decreased in HCC tumors and can serve as a prognostic biomarker for HCC. Expressions of MICA and EHHADH exhibited significant correlations with various phenotypic macrophages and exerted opposing effects on M1-like and M2-like macrophages infiltrating HCC. The underlying metabolic and molecular mechanisms revealed that MICA in tumor cells induced M2-like polarization through the PPAR/EHHADH pathway, which regulates the fatty acid oxidation (FAO) in macrophages. Conclusions: The metabolic gene EHHADH, which is associated with MICA, led to alterations in M2-like macrophages by promoting heightened fatty acid uptake and augmenting levels of FAO within macrophages. Full article