Search Results (5,117)

Groundwater in the Qingshui River Plain of southern Ningxia is one of the main water sources for local domestic and agricultural use. However, due to the geological background of the area, 33.94% of the groundwater samples had fluoride concentrations that exceeded the WHO drinking water standards. To examine the spatial patterns and formation processes of fluoride in groundwater, researchers gathered 79 rock samples, 2618 soil samples, 21 sediment samples, 138 groundwater samples, and 82 surface water samples across the southern Qingshui River Plain. The collected data were analyzed using statistical approaches and hydrogeochemical diagrams. The findings reveal that fluoride levels in groundwater exhibit a gradual increase from the eastern, western, and southern peripheral sloping plains toward the central valley plain. Vertically, higher fluoride concentrations are found within 100 m of depth. Over a ten-year period, fluoride concentrations have shown minimal variation. Fluoride-rich rocks, unconsolidated sediments, and soils are the primary sources of fluoride in groundwater. The primary mechanisms governing high-fluoride groundwater formation are rock weathering and evaporative concentration, whereas cation exchange adsorption promotes fluoride (F⁻) mobilization into the aquifer. Additional sources of fluoride ions include leaching of fluoride-rich sediments during atmospheric precipitation infiltration and recharge from fluoride-rich surface water. Full article

Environmental persistent free radicals (EPFRs) represent a class of long-lived, redox-active species with half lives spanning minutes to months. Emerging as critical environmental pollutants, EPFRs pose significant risks due to their persistence, potential for bioaccumulation, and adverse effects on ecosystems and human health. This review critically synthesizes recent advancements in understanding EPFR formation mechanisms, analytical detection methodologies, environmental distribution patterns, and toxicological impacts. While progress has been made in characterization techniques, challenges persist—particularly in overcoming limitations of electron paramagnetic resonance (EPR) spectroscopy and spin-trapping methods in complex environmental matrices. Key knowledge gaps remain, including molecular-level dynamics of EPFR formation, long-term environmental fate under varying geochemical conditions, and quantitative relationships between chronic EPFR exposure and health outcomes. Future research priorities could focus on: (1) atomic-scale mechanistic investigations using advanced computational modeling to resolve formation pathways; (2) development of next-generation detection tools to improve sensitivity and spatial resolution; and (3) integration of EPFR data into region-specific air-quality indices to enhance risk assessment and inform mitigation strategies. Addressing these gaps will advance our capacity to mitigate EPFR persistence and safeguard environmental and public health. Full article

The lower sub-member of Member 2, Dongying Formation (Paleogene) in the HHK Depression hosts an extensively developed thin-bedded beach-bar system characterized by favorable source rock conditions and reservoir properties, indicating significant hydrocarbon exploration potential. Integrating drilling cores, wireline log interpretations, three-dimensional seismic data, geochemical analyses, and palynological data, this study investigates the sedimentary characteristics, sandbody distribution patterns, controlling factors, and genetic model of this lacustrine beach-bar system. Results reveal the following: (1) widespread thin-bedded beach-bar sandbodies dominated by fine-grained sandstones and siltstones, exhibiting wave ripples and low-angle cross-bedding; (2) two vertical stacking patterns, Type A, thick mudstone intervals intercalated with laterally continuous thin sandstone layers, and Type B, composite sandstones comprising thick sandstone units overlain by thin sandstone beds, both demonstrating significant lateral continuity; (3) three identified microfacies: bar-core, beach-core, and beach-margin facies; (4) key controls on sandbody development: paleoenvironmental evolution establishing the depositional framework, secondary fluctuations modulating depositional processes, strike-slip extensional tectonics governing structural zonation, paleobathymetry variations and paleotopography controlling distribution loci, and provenance clastic influx regulating scale and enrichment (confirmed by detrital zircon U-Pb dating documenting a dual provenance system). Collectively, these findings establish a sedimentary model for a thin-bedded beach-bar system under the strike-slip extensional tectonic framework. Full article

A Cournot triopoly is a type of oligopoly market involving three firms that produce and sell homogeneous or similar products without cooperating with one another. In Cournot models, firms’ decisions about production levels play a crucial role in determining overall market output. Compared to duopoly models, oligopolies with more than two firms have received relatively less attention in the literature. Nevertheless, triopoly models are more reflective of real-world market conditions, even though analyzing their dynamics remains a complex challenge. A reaction–diffusion system of PDEs generalizing a nonlinear triopoly model describing a master–slave Cournot game is introduced. The effect of diffusion on the stability of Nash equilibrium is investigated. Self-diffusion alone cannot induce Turing pattern formation. In fact, linear stability analysis shows that cross-diffusion is the key mechanism for the formation of spatial patterns. The conditions for the onset of cross-diffusion-driven instability are obtained via linear stability analysis, and the formation of several Turing patterns is investigated through numerical simulations. Full article

Antibiotic resistance and biofilm formation complicate Staphylococcus aureus infections, raising concerns for global health. Understanding antimicrobial resistance and biofilm formation in these pathogens is essential for effective infection management. The current research aimed to assess antibiotic resistance patterns, biofilm formation, and the occurrence of integron classes 1, 2, and 3 in clinical S. aureus isolates. The disc diffusion method tested antibiotic susceptibility. MRSA strains were identified by cefoxitin disc diffusion, and the mecA gene by PCR. The D-test also assessed macrolide–lincosamide–streptogramin B. A microtiter plate assay assessed biofilm formation. By PCR, integron classes were examined. Of the 63 S. aureus isolates, 25 were MSSA and 38 were MRSA. Pus (39.5%) was the most prevalent clinical source of MRSA isolates, while blood (24%) was the predominant source of MSSA isolates. MRSA isolates were more resistant to clindamycin, ciprofloxacin, ofloxacin, levofloxacin, tetracycline, and doxycycline than MSSA isolates. In total, 76.2% of the isolates produced biofilm. Biofilm-producing isolates were more resistant to cefoxitin and clindamycin. The isolates had 33.3% cMLSB resistance. The intI1 gene was found in 21 S. aureus isolates (33.3%), whereas the intI2 or intI3 genes were not detected. Our findings demonstrate the need for strict infection control to prevent the spread of resistant bacteria. Full article

The formation and development of mushrooms depend on suitable conditions of humidity, substrate, and temperature. These environmental factors are directly influenced by ongoing climate change, which may alter fungal growth patterns, distribution, and morphology. However, these attributes remain inadequately investigated in Antarctic mushrooms. In this study, we examined 334 basidiomes of Arrhenia antarctica, discovered on Livingston Island in 2023. The morphological characteristics of these basidiomes were analyzed to explore how recent variations may be linked to and explained by climatic changes. Comparing the original description from over 60 years ago with the recent literature on the subject, we observed a larger pileus diameter (47.3% of basidiomes with diameters exceeding 23 mm, up to 75 mm) than previously documented (reported as up to 23 mm). Additionally, there were changes in pileus morphology, with not all of them exhibiting an umbilicate form, contrary to the references. We propose that these morphological variations may be attributed to climatic changes. The basidiomata were also found in association with pure Antarctic grass banks, prompting the question of whether Arrhenia antarctica is indeed a moss parasite. The information presented in this study aims to support ongoing research on the taxonomy and diversity of Agaricales fungi in Antarctica. Full article

About one third of all food produced for human consumption is lost or wasted, leading to societal, economic and environmental challenges. This study identifies the most important food wastage (FW) leverage points and their interrelations with specific food chains. Semi-structured interviews were conducted across four different food chains (milk, poultry, potatoes and greenhouse-grown fruit and vegetables) from primary production to food service. The outcomes of the interviews were summarized via a systems approach and validated during co-creation sessions. A total of twenty-two FW leverage points were identified across the food chains, consisting of four major hotspots, six patterns of behaviours, six structures and six mental models. Common transformative leverage points across all food chains were damaged products, oversupply, regulations and standards that limit product use and a lack of prioritization of FW reduction. Additionally, this study found that co-creation sessions with stakeholders from across the food chains could facilitate the formation of coalitions of willing companies, encouraging collaborative efforts to reduce FW. Full article

Background: The regulation of oil and protein contents in cottonseed is governed by a complex genetic network. Gaining insight into the mechanisms controlling these traits is necessary for dissecting the formation patterns of cottonseed quality. Method: In this study, Xinluzhong 37 (P₁) and Xinluzhong 51 (P₂) were selected as parental lines for two reciprocal crosses: P₁ × P₂ (F₁) and its reciprocal P₂ × P₁ (F₁′). Each F1 was selfed and backcrossed to both parents to generate the F₂ (F₂′), B₁ (B₁′), and B₂ (B₂′) generations. To assess nutritional traits in hairy (non-delinted) and lint-free (delinted) seeds, two indicators, oil content and protein content, were measured in both seed types. Joint segregation analysis was employed to analyze the inheritance of these traits, based on a major gene plus polygene model. Results: In the orthogonal crosses, the CVs for the four nutritional traits ranged at 2.710–7.879%, 4.086–11.070%, 2.724–6.727%, and 3.717–9.602%. In the reciprocal crosses, CVs ranged at 2.710–8.053%, 4.086–9.572%, 2.724–6.376%, and 3.717–8.845%. All traits exhibited normal or skewed-normal distributions. For oil content in undelinted/delinted seeds, polygenic heritabilities in the orthogonal cross were 0.64/0.52, and 0.40/0.36 in the reciprocal cross. For protein content, major-gene heritabilities in the orthogonal cross were 0.79 (undelinted) and 0.78 (delinted), while those in the reciprocal cross were both 0.62. Conclusions: Oil and protein contents in cottonseeds are quantitative traits. In both orthogonal and reciprocal crosses, oil content is controlled by multiple genes and is shaped by additive, dominance, and epistatic effects. Protein content, in contrast, is largely controlled by two major genes along with minor genes. In the P₁ × P₂ combination, major genes act through additive, dominance, and epistatic effects, while in the P₂ × P₁ combination, their effects are additive only. In both combinations, minor genes contribute through additive and dominance effects. In summary, the oil content in cottonseed is mainly regulated by polygenes, whereas the protein content is primarily determined by major genes. These genetic features in both linted, and lint-free seeds may offer a theoretical foundation for molecular breeding aimed at improving cottonseed oil and protein quality. Full article

Background/Objectives: The formation of oral biofilms in periodontal pockets and around dental implants with induction of periodontitis or peri-implantitis is an increasing problem in dental health. The intelligent design of a biofilm makes the bacteria embedded in the biofilm matrix highly tolerant to antiseptic therapy, often resulting in tooth or implant loss. The question therefore arises as to which mouthwashes have eradication potential against oral biofilm. Methods: A human oral biofilm model was developed based on donated blood plasma combined with buffy coats, inoculated with oral pathogenic bacterial species found in periodontal disease (Actinomyces naeslundii, Fusobacterium nucleatum, Streptococcus mitis, and Porphyromonas gingivalis). Over a span of 7 days, we tested different mouth rinsing and antiseptic solutions (Chlorhexidine, Listerine^®, NaOCl, Octenisept^®, and Octenident^®) covering the matured biofilm with 24 h renewal. Phosphate-buffered saline (PBS) was used as a control. Bacterial growth patterns were detected via quantitative polymerase chain reaction (qPCR) after 2, 4, and 7 days of treatment. Results: While all groups showed initial bacterial reduction, the control group demonstrated strong regrowth from day 2 to 4. Listerine showed a near-significant trend toward bacterial suppression. Additionally, strain-specific efficacy was observed, with Octenisept^® being most effective against Streptococcus mitis, Octenident^® and NaOCl showing superior suppression of Actinomyces naeslundii, and Listerine^® outperforming other solutions in reducing Fusobacterium nucleatum. Donor-specific, individual variability further influenced treatment outcomes, with distinct trends in bacterial suppression and regrowth observed across donors. Conclusions: These findings underscore the complexity of biofilm-associated infections and highlight the importance of targeted therapeutic approaches for managing bacterial biofilms. In this experiment, the donor-specific outcomes of the antimicrobial effects of the solutions may indicate that genetic predisposition/tolerance to oral infections appears to play a critical role in the control of oral biofilms. Full article

This study focuses on S32654 super austenitic stainless steel (SASS) and systematically characterizes the morphology of the sigma (σ) phase and the segregation behavior of alloying elements in its as-cast microstructure. High-temperature confocal scanning laser microscopy (HT-CSLM) was employed to investigate the effect of the rare earth element yttrium (Y) on the solidification microstructure and σ phase precipitation behavior of SASS. The results show that the microstructure of SASS consists of austenite dendrites and interdendritic eutectoid structures. The eutectoid structures mainly comprise the σ phase and the γ₂ phase, exhibiting lamellar or honeycomb-like morphologies. Regarding elemental distribution, molybdenum displays a “concave” distribution pattern within the dendrites, with lower concentrations at the center and higher concentrations at the sides; when Mo locally exceeds beyond a certain threshold, it easily induces the formation of eutectoid structures. Mo is the most significant segregating element, with a segregation ratio as high as 1.69. The formation mechanism of the σ phase is attributed to the solid-state phase transformation of austenite (γ → γ₂ + σ). In the late stages of solidification, the concentration of chromium and Mo in the residual liquid phase increases, and due to insufficient diffusion, there are significant compositional differences between the interdendritic regions and the matrix. The enriched Cr and Mo cause the interdendritic austenite to become supersaturated, leading to solid-state phase transformation during subsequent cooling, thereby promoting σ phase precipitation. The overall phase transformation process can be summarized as L → L + γ → γ → γ + γ₂ + σ. Y microalloying has a significant influence on the solidification process. The addition of Y increases the nucleation temperature of austenite, raises nucleation density, and refines the solidification microstructure. However, Y addition also leads to an increased amount of eutectoid structures. This is primarily because Y broadens the solidification temperature range of the alloy and prolongs grain growth perio, which aggravates the microsegregation of elements such as Cr and Mo. Moreover, Y raises the initial precipitation temperature of the σ phase and enhances atomic diffusion during solidification, further promoting σ phase precipitation during the subsequent eutectoid transformation. Full article

As a strategic replacement area for hydrocarbon exploration in the Tarim Basin, the Kuqa Depression has been the subject of relatively limited research on the sedimentary characteristics of the Triassic strata within its western Wushi Sag, which constrains exploration deployment in this region. This study focuses on the Wushi Sag, systematically analyzing the sedimentary facies types, the evolution of sedimentary systems, and the distribution patterns of the Triassic Kelamayi and Huangshanjie formations. This analysis integrates field outcrops, drilling cores, wireline logs, and 2D seismic data, employing methodologies grounded in foreland basin theory and clastic sedimentary petrology. The paleo-geomorphology preceding sedimentation was reconstructed through balanced section restoration to investigate the controlling influence of foreland tectonic movements on the distribution of sedimentary systems. By interpreting key seismic profiles and analyzing vertical facies successions, the study classifies and evaluates the petroleum accumulation elements and favorable source–reservoir-seal assemblages, culminating in the prediction of prospective exploration areas. The research shows that: (1) The Triassic in the Wushi Sag mainly develops fan-delta, braided-river-delta, and lacustrine–shallow lacustrine sedimentary systems, with strong planar distribution regularity. The exposed strata in the northern part are predominantly fan-delta and lacustrine systems, while the southern part is dominated by braided-river-delta and lacustrine systems. (2) The spatial distribution of sedimentary systems was demonstrably influenced by tectonic activity. Paleogeomorphological reconstructions indicate that fan-delta and braided-river-delta sedimentary bodies preferentially developed within zones encompassing fault-superposition belts, fault-transfer zones, and paleovalleys. Furthermore, Triassic foreland tectonic movements during its deposition significantly altered basin configuration, thereby driving lacustrine expansion. (3) The Wushi Sag exhibits favorable hydrocarbon accumulation configurations, featuring two principal source–reservoir assemblages: self-sourced structural-lithologic gas reservoirs with vertical migration pathways, and lower-source-upper-reservoir structural-lithologic gas reservoirs with lateral migration. This demonstrates substantial petroleum exploration potential. The results provide insights for identifying favorable exploration targets within the Triassic sequences of the Wushi Sag and western Kuqa Depression. Full article

This study investigates the coupling mechanism between a parabolic notch and dislocations in one-dimensional (1D) hexagonal piezoelectric quasicrystals (PQCs) based on the theory of complex variable functions. By applying perturbation techniques and the Cauchy integral, analytical solutions for complex potentials are derived, yielding closed-form expressions for the phonon–phason stress field and electric displacement field. Numerical examples reveal several key findings: significant stress concentration occurs at the notch root, accompanied by suppression of electric displacement; interference patterns between dislocation cores and notch-induced stress singularities are identified; the J-integral quantifies distance-dependent forces, size effects, and angular force distributions reflecting notch symmetry; and the energy-driven dislocation slip toward free surfaces leads to the formation of dislocation-free zones. These results provide new insights into electromechanical fracture mechanisms in quasicrystals. Full article

The human need for belonging and identity (stemming from the need for belonging) is strong. This article begins by discussing these needs, drawing on the theories of Abraham Maslow and Erik Erikson. Forceful societal trends in the early twenty-first-century world have been creating a new societal context that tends to disrupt historical, relatively simple trajectories of identity formation. These trends are then subsumed under two megatrends that operate in the contemporary world. The first is globalisation, evident in the world since c.1990 as “Globalisation 3.0”. One outcome of Globalisation 3.0 is identity flux. Around 2015, a trend of deglobalisation became evident around the world. Populism is one of the manifestations of this counter-trend, a manifestation that is also visible in identity formation patterns. Education, citizenship educationin particular, has long been looked up to as instrument of political socialisation and identity formation, and these counter-trends tend to impact it, as well. The thesis of this article is that citizenship education, as it is presented in the education systems of the contemporary world, could be deemed to be anachronistically simple and hence requires adaptations in response to the exigencies of this new, changed global context. Finally, we suggest some guidelines for a reconceptualised citizenship education attuned to the exigencies of the new unfolding global context. Full article

The hydraulic turbine serves as the cornerstone of hydropower generation systems, with the sealing system’s performance critically influencing energy conversion efficiency and operational cost-effectiveness. The sealing ring is a pivotal component, which mitigates leakage and energy loss by regulating flow within the narrow gap between itself and the frame. This study investigates the intricate flow dynamics within the gap between the sealing ring and the upper frame of a super-large-scale Francis turbine, with a specific focus on the rotating wall’s impact on the flow field. Employing theoretical modeling and three-dimensional transient computational fluid dynamics (CFD) simulations grounded in real turbine design parameters, the research reveals that the rotating wall significantly alters shear flow and vortex formation within the gap. Tangential velocity exhibits a nonlinear profile, accompanied by heightened turbulence intensity near the wall. The short flow channel height markedly shapes flow evolution, driving the axial velocity profile away from a conventional parabolic pattern. Further analysis of rotation-induced vortices and flow instabilities, supported by turbulence kinetic energy monitoring and spectral analysis, reveals the periodic nature of vortex shedding and pressure fluctuations. These findings elucidate the internal flow mechanisms of the sealing ring, offering a theoretical framework for analyzing flow in microscale gaps. Moreover, the resulting flow field data establishes a robust foundation for future studies on upper crown gap flow stability and sealing ring dynamics. Full article

Background/Objectives: Although technology has progressed and novel dosage forms have been developed, tablets are still the most used form of medication. However, the present manufacturing methods of these oral solid dosage forms offer limited capacity for personalized treatment and adaptable dosing. Personalized therapy, with a few exceptions, is not yet a part of routine clinical practice. Drug printing could be a possible approach to increase the use of personalized therapy. The aim of this work was to investigate the role of surface tension and the viscosity of inks in the formation of the printing pattern and to investigate how the porosity of substrate tablets influences the behavior of inks on the surface. Methods: Spray-dried mannitol served as a binder and filler, while magnesium stearate functioned as a lubricant in the preparation of substrate tablets. Brilliant Blue dye was a model “drug”. The ink formulation was applied to the substrates in three varying quantities. Results: Increasing the viscosity enhanced the drug content, potentially improving printing speed and pattern accuracy. However, it negatively impacted the dosing accuracy due to nozzle clogging and prolonged drying time. Viscosity had a significantly higher impact on the ink behavior than surface tension. Lowering the surface tension improved the dosing accuracy and reduced the drying time but resulted in smaller drop sizes and decreases in pattern accuracy. Reducing the substrate porosity led to longer drying times and diminished pattern accuracy. Conclusions: A target surface tension of around 30 mN/m is suggested for inkjet printing. It is necessary to further investigate the applicability of the technology with solutions of inks with high viscosity and low surface tension, including the API. Full article