Search Results (2,649)

The Sinian (Ediacaran) Dengying Formation in the northeastern Sichuan Basin exhibits a significant exploration potential. Nevertheless, the great burial depth of carbonates in the Dengying Formation and the scarcity of drilling data have imposed constraints on in-depth investigations into the evolution of lithofacies paleogeography as well as the primary controlling mechanisms. Through integrated analysis of field outcrops, core and well logging data, the evolution of the lithofacies and paleogeography of the Dengying Formation in the northeastern Sichuan Basin was reconstructed by using 3D stratigraphic forward modeling. The study area is predominantly characterized by platform margin facies and restricted platform facies, comprising four subfacies including microbial (algal) mound, grain shoal, intershoal sea, and intraplatform depression. The microbial (algal) mound and grain shoal subfacies are primarily developed along the western and eastern platform margins, exhibiting a near north–south trend. Scattered mound–shoal complexes and intershoal sea occur within the platform, with localized intraplatform depression zone. During the depositional stage of the Dengying Formation, three primary paleogeomorphic units were developed including the platform margin topographic high zone, intraplatform gentle slope zone, and intraplatform depression zone. During the Deng-1 and Deng-3 periods, sea level rise increased accommodation space, leading to a gradual decline in carbonate productivity and limited development of the mound–shoal complexes. In contrast, during the Deng-2 and Deng-4 periods, sea level decreased, water depth decreased, and carbonate productivity was enhanced, resulting in extensive development of the mound–shoal complexes. The simulation results indicate that carbonate-producing ecosystems thrive when wind blows from 270° W (80% frequency) or 15° N (60% frequency); with an effective water depth of 10–20 m, the elevated carbonate productivity is conducive to the growth of biogenic calcification. Comprehensive analysis suggests that paleogeomorphology, eustatic fluctuations, and paleowind fields collectively control the distribution and evolution of the lithofacies in the Dengying Formation in the northeastern Sichuan Basin. Paleogeomorphology governs the types and distribution of sedimentary facies belts as well as the spatial arrangement of lithofacies. Eustasy determines the magnitude of mound–shoals and their lateral migration. Three-dimensional stratigraphic forward modeling offers a novel approach for reconstructing paleogeographic evolution of carbonate platforms and analyzing key controlling factors, while also enhancing our ability to predict the distribution patterns of mound–shoal complexes. Full article

Soil erosion intensifies the redistribution and loss of soil nutrients. However, how erosion–deposition processes shape the spatial patterns of soil total nitrogen to total phosphorus (TN:TP) ratio in long-term eroded landscapes remains poorly understood. In this study, we examined the spatial variability of TN, TP, and the N:P ratio and their driving factors across a 7-ha sloping black-soil cropland in northeast China. Results showed that mean topsoil concentrations of TN and TP were 1.7 and 0.7 g kg⁻¹, respectively, and the corresponding N:P ratio averaged 5.2, which was 46.6% lower than the Chinese average. Erosion–deposition effects were strongly depth dependent. In the 20–40 cm soil layer, all three variables declined in strongly eroded zones but increased in depositional areas, whereas in the 0–20 cm layer they were lower in depositional zones than in weakly eroded zones, indicating a vertical decoupling of nutrient redistribution under prolonged erosion. Notably, variability in soil N:P was closely associated with TN, soil organic carbon, and silt content, with TN emerging as the dominant control, as reflected by its stronger correlation with N:P (p ≤ 0.001) and higher variability (CV = 21.7–35.8%) relative to TP. Although elevation and slope gradient both influenced N:P spatial variability, only elevation showed a significant negative correlation (p ≤ 0.05). These findings indicate that, compared with TP, TN is more sensitive to long-term soil erosion and deposition and dominates the spatial pattern of the N:P ratio. The enhanced role of TN may increase the risk of N limitation in eroded farmlands. This study provides insights into the mechanisms of nutrient imbalance in eroded black soil regions and offers a scientific basis for formulating targeted soil conservation and fertility enhancement measures. Full article

Unfavorable flow patterns, such as vortices and backflow in pump station forebays, can deteriorate pump suction conditions and exacerbate sediment deposition. This study investigates the effects of different pump unit operation combinations on the flow patterns in the forward-intake forebay of the Hongsi Pumping Station. A three-dimensional numerical model was established using the RNG k-ε turbulence model combined with the VOF method for free surface tracking, with Enhanced Wall Treatment employed for the near-wall region. The model was validated against field measurements, with mean absolute errors of 0.058 and 0.085 for two characteristic lines, respectively. Four unit operation combination schemes were simulated and compared. Results show that the velocity in the front end of the main flow zone reaches 0.344–0.345 m/s across all schemes, which is 19–24% higher than in the middle section and 26–37% higher than in the rear section. The inter-scheme velocity variation is minimal near the forebay inlet (1.1% at section X1) but increases significantly near the pump inlets (approximately 11% at section X4), indicating that unit operation combinations primarily affect the rear forebay region. Large-scale vortices are observed near the side walls and pump inlets, with vortex cores located at different positions depending on the operation scheme. When the units at both ends are operated symmetrically (Scheme 1: units 1#, 2#, 5#, 6#), the flow pattern is the most favorable, displaying characteristic dual-core vorticity distribution with symmetric pattern and moderate intensity, with the velocity uniformity at the inlet section reaching 81.77%, which is 5.21, 11.35, and 1.91 percentage points higher than Schemes 2, 3, and 4, respectively. For practical operation, Scheme 4 (1#, 2#, 4#, 5#) can serve as an alternative with a velocity uniformity of 79.86%, while central concentration and single-side bias configurations should be avoided due to their larger vortex scales and lower velocity uniformity. The findings provide quantitative guidance for the operation management of forward-intake pump stations. Full article

Determining the age and origin of the “Huoshan Sandstone” holds significant geological implications for the stratigraphic division and correlation of Precambrian sequences in the North China Craton, provenance analysis, reconstruction of tectonic–sedimentary patterns, and paleogeographic settings restoration. This paper investigates the petrology, zircon U-Pb dating, Hf isotopes analysis, and zircon microzonation geochemistry of the “Huoshan Sandstone”. The “Huoshan Sandstone” is grayish-white, light gray, light yellow, purplish-red quartzitic sandstone and quartz sandstone, with a quartz content ranging from 85.5% to 97.8%. The quartz grains exhibit relatively straight contact edges, characteristic of low-grade metamorphosed quartzite. The protolith of the “Huoshan Sandstone” is a medium-grained quartz sandstone with dominant grain sizes of 0.30~0.50 mm, exhibiting well-rounded to subrounded grains and highly developed siliceous cementation characterized by secondary overgrowth. The zircon Th/U ratio confirms that the zircons in the “Huoshan Sandston” are mainly magmatic zircons. Most zircons exhibit extreme HREE enrichment and left-sloping REE patterns, and show significant positive Ce anomalies (Ce/Ce* of 1.06~290.68) and negative Eu anomalies (Eu/Eu* of 0.065~0.61). The age range of zircon ²⁰⁷Pb/²⁰⁶Pb is 1770 ± 20~2732 ± 16 Ma, and there are two obvious peaks at 1800 and 2500 Ma in the U-Pb age frequency histogram, the age of the intersection point on the concordia line is 2521 ± 31 Ma, and the age of the intersection point on the lower part of the line is 1829 ± 22 Ma. These two ages correspond to the timing of Neoarchean TTG gneiss formation through oceanic crust partial melting in the central North China Craton, and the ~1.85 Ga Paleoproterozoic thermal metamorphic event recorded in the Zhongtiao Group of the same region, respectively. The maximum depositional age of the “Huoshan Sandstone”, constrained by the youngest detrital zircon U-Pb ages at 1770 ± 20 Ma, indicates that its sedimentation occurred after 1770 ± 20 Ma (Late Late Paleoproterozoic). Furthermore, as it underlies the red shales of the Cambrian Mantou Formation as a distinct tectonic layer, it must have formed prior to the deposition of the Cambrian Mantou Formation. In addition, in situ Lu-Hf isotopic analyses of these zircons yielded two-stage model ages, mainly between 2.5 and 2.8 Ga, suggesting the provenance to be the Precambrian basement of the Zhongtiao Mountain region in the central North China Craton. It is inferred that the Precambrian strata in the Zhongtiao Mountain area were involved in the process of subduction, collage, and collision of the two continental blocks of the eastern and western parts of the North China Craton, and further confirmation is provided that the final collision of the two continental blocks to form the central orogenic belt occurred in the late Palaeoproterozoic. Full article

Background/Objectives: Cardiomyopathy (CM) is a leading cause of morbidity and mortality in Duchenne muscular dystrophy (DMD) patients. Ferroptosis, an iron-dependent form of cell death characterized by lipid peroxidation, is implicated in various cardiovascular diseases. However, the role of ferroptosis in DMD-CM remains unexplored. Methods: Here, we used dystrophin and utrophin double-knockout (mdx:utr^−/−) mice as a model that exhibits cardiac pathological phenotypes similar to those seen in DMD patients to investigate the potential role of ferroptosis. Results: We observed an increased level of iron deposition and lipid peroxidation in the hearts of mdx:utr^−/− mice. Live/Dead viability assays revealed that mdx:utr^−/− cardiomyocytes exhibited greater susceptibility to ferroptosis than WT cardiomyocytes both at baseline and upon exposure to ferroptosis inducers. We also used mdx:utr^−/− mice with a heterozygous sarcolipin (SLN) knockout background (sln^+/−) to investigate the effect of SLN reduction on ferroptosis susceptibility in DMD-CM. Notably, ferroptosis was significantly suppressed in cardiomyocytes from mdx:utr^−/−:sln^+/− mice (p < 0.01). Western blot analysis confirmed the upregulation of transferrin receptor 1 (TfR1) and 15-lipoxygenase-1 (15LOX1), along with the downregulation of heme oxygenase-1 (HMOX-1) and ferroptosis suppressor protein 1 (FSP1) in mdx:utr^−/− hearts, while glutathione peroxidase 4 (GPX4) levels remained unchanged. A similar pattern of alterations in ferroptosis-related biomarkers was observed in human heart samples from DMD patients compared to healthy controls. Conclusions: Our results provide direct evidence that ferroptosis contributes to the pathology of DMD-CM and suggest that reducing SLN expression and inhibiting ferroptosis may represent potential therapeutic strategies for this condition. Full article

Circular economy (CE) decouples value creation from virgin resource use and waste in the medical device sector, which faces stringent patient-safety, quality, and regulatory obligations. Green Additive Manufacturing (AM) offers a precise, digitally driven route to implement CE through dematerialization, on-demand localized production, topology optimization, and material circularity. In this study, a comprehensive CE framework is tailored to medical device manufacturing that integrates eco-design, material circularity, remanufacturing, and regulatory compliance across the product life cycle. Methods include an International Organization for Standardization (ISO) 14040/44-aligned life cycle assessment, process energy metering, sterilization-compatibility studies, mechanical/biocompatibility verification to relevant standards, and a techno-economic/circularity analysis with Monte Carlo uncertainty quantification. Three case studies are explored using bio-based PA11 (selective laser sintering), recycled polyethylene terephthalate glycol (fused deposition modeling), and low-volatile organic carbon biocompatible photopolymer (stereolithography): (1) a patient-specific wrist orthosis, (2) a dental surgical guide, and (3) a single-use catheter Y-connector. Results indicate 38–68% reductions in embodied greenhouse-gas emissions, 22–54% energy savings per functional unit, and up to 80% mass recapture through in-process powder/runner reuse while maintaining clinical performance and regulatory conformity. Design-for-circularity patterns (DfC) were created for DfDisassembly, DfSter, DfTraceability, DfUpgrade, and DfPowder-Loop and provide a governance architecture combining ISO 13485 QMS, ISO 10993 biological evaluation, the European Union’s Medical Device Regulation (Regulation (EU) 2017/745), and the United States Food and Drug Administration’s guidance on Additive Manufactured (3D-printed) medical devices, guidance with unique device identification for closed-loop returns. The paper concludes with an Industry 5.0 roadmap for hospital-proximate micro-factories, materials passports, and digital product passports enabling verified circular flows at scale. Full article

Background: The spike D614G substitution became globally dominant early in the COVID-19 pandemic, and reversion to ancestral D614 is expected to be rare once D614G is fixed. SARS-CoV-2 sequences lacking D614G detected later raise questions about the origin of these reversions. Methods: We analyzed spike protein amino-acid sequences from 22 SARS-CoV-2 Variants of Concern (VOCs) deposited in the NCBI GenBank database, screening for sequences carrying ancestral D614 and comparing their distributions across VOCs. Results: D614 reversions (reverse mutations of D614G) were not evenly distributed across VOCs but were strongly enriched in Delta (B.1.617.2) and Omicron BA.2, reaching levels statistically inconsistent with other VOCs. In both lineages, D614-containing sequences showed limited mutational diversity and pronounced geographic clustering within specific U.S. regions. Conclusions: These non-random patterns are difficult to reconcile with spontaneous reverse mutation arising and spreading through typical community transmission and are more consistent with localized reintroduction of an older genetic background. Further investigation is warranted to assess whether laboratory-associated events could be involved. Full article

Extreme rainfall events often trigger landslides, debris flows, and sediment-laden floods that cause severe damage in built-up areas, yet sediment deposition is rarely quantified in hazard assessments. This study evaluates the capability of the physically based catchment model LISEMHazard to reconstruct sediment generation, transport, and deposition during Hurricane Maria (2017) in two catchments in Dominica (Coulibistrie and Grand Bay). Simulations were performed at 10 m resolution using rainfall, topography, soil, and land-use data. Model calibration and validation used mapped landslides and debris flows, field measurements of deposition height, and DEMs of Difference (DoDs). LISEMHazard reproduced the general magnitude of sediment volumes and the frequency–area distribution of medium and large landslides but showed poor ability to predict their exact locations and overestimated landslide depth and deposition height. Agreement between modeled and observed debris-flow patterns was good in major channels but weak in minor ones. Sensitivity analysis indicated that soil depth and cohesion dominate uncertainties, whereas saturated hydraulic conductivity and surface roughness exert minimal influence. Despite substantial data and model limitations, physically based modeling remains a practical approach for spatial estimation of sediment deposition needed for risk assessment, structural damage evaluation, and cleanup cost estimation. Full article

The stratigraphic evolution of low-latitude carbonate platforms, highly sensitive to sea-level changes, is often poorly constrained due to limited core data and discontinuous depositional records. This study elucidates the evolution of the Meiji Atoll, a representative low-latitude platform in the southern South China Sea (SCS), since the late Miocene, using the reef-penetrating core (Well NK1) from Nansha Island. By integrating facies analysis, sequence stratigraphy, and geochemical proxies, we identified two third-order sequences (SQ1 and SQ2), each comprising transgressive (TST) and highstand (HST) systems tracts. Geochemical data indicate that TSTs were associated with enhanced upwelling and nutrient availability, fostering algal productivity, while HSTs were marked by subaerial exposure. The overall retrogradational stacking pattern of the atoll reflects a dominant control by long-term sea-level rise, superimposed by eustatic fluctuations. Our findings confirm that eustatic sea-level variations were a primary factor controlling the stratigraphic architecture and development of Cenozoic low-latitude carbonate systems. Full article

This study investigated antibacterial dentures fabricated by peening titanium apatite onto a polymethyl methacrylate (PMMA) denture base resin using a peening device. The effects of different peening mass flow rates and total peening masses on the deposition and antibacterial properties of titanium apatite were investigated. Titanium apatite was peened onto PMMA specimens at mass flow rates of 1, 2, and 5 g/s, with total peening masses of 5, 10, and 15 g. The surface morphology, elemental distribution, and mass changes were analyzed before and after peening and after immersion and water rinsing. The antibacterial activity against Staphylococcus aureus was evaluated using a crystal violet assay. The results showed that reducing the peening mass flow rate increased the amount of titanium apatite transferred and enhanced the antibacterial properties, with the highest deposition achieved at 1 g/s. Varying the total peening mass did not significantly affect the deposition pattern or antibacterial activity. The arithmetic mean roughness of the denture base remained unchanged after peening, indicating its clinical applicability. In conclusion, peening titanium apatite onto PMMA at a lower mass flow rate enabled stronger bonding and incorporation of antibacterial properties, potentially contributing to the development of novel antibacterial denture base materials. Full article

Understanding the pathways through which heavy metals accumulate in medicinal plants and enter herbal infusions is essential for linking environmental quality with human exposure. This study investigated multi-matrix metal transfer in Tilia spp. along an urban–forest gradient by quantifying twelve elements (Pb, Cd, Zn, Cu, Ni, Cr, Mn, Co, As, Hg, Al, and V) in soil, bark, leaves, flowers, and corresponding infusions using inductively coupled plasma mass spectrometry and by estimating daily intake for different age groups based on EFSA default body weights and two consumption scenarios (150 and 400 mL day⁻¹). The results revealed clear spatial patterns, with significantly higher metal loads in urban sites and a consistent transfer from environmental compartments to plant tissues and infusions. Mn, Al, Pb, and Cd exhibited the highest extractability, leading to elevated estimated daily intakes in young children, identified as the most vulnerable group due to their lower body mass. However, all exposure values remained below EFSA and JECFA toxicological reference limits, while As and Hg were undetectable in all infusions. These findings indicate that Tilia infusions contribute minimally to overall dietary metal exposure and confirm Tilia spp. as reliable bioindicators of soil- and airborne metal deposition, supporting the safe consumption of linden tea under realistic intake conditions. Full article

Natural floodplain vegetation exhibits heterogeneous patterns in height and density that substantially affect flow and bed stability. Most previous studies have examined flows through uniformly distributed vegetation, resulting in a limited understanding of mixed-height canopies. Consequently, existing methods for estimating bed shear stress remain inadequately validated under such heterogeneous conditions. To bridge this gap, we conducted flume experiments to investigate how the density and height configuration of rigid vegetation affect the spatial distribution of bed shear stress, comparing three commonly used approaches: the Law of the Wall, Reynolds stress, and turbulent kinetic energy (TKE). Results showed strong agreement between TKE and Reynolds stress methods; the Law of the Wall produced larger errors (15–25%) due to log-layer disruption in vegetated zones, limiting its use. Vegetation density dominated bed shear stress: high-density areas reduced mean stress by 17–36%, promoting deposition, whereas tall–short vegetation interfaces increased local stress by 15–26%, elevating scour risk. Flow velocity raised overall stress by 15–25%, while water depth had minimal effect. Sparse vegetation led to patchy stress distributions and higher scour potential, while dense vegetation favored uniform stress and sediment accumulation. These findings clarify bed shear stress mechanisms in heterogeneous vegetation and provide a basis for floodplain restoration and stability management. Full article

Multi-outlet air-assisted sprayers are increasingly used for directional and zoned airflow to match varying canopy structures. In this study, a self-developed multi-outlet orchard air-assisted sprayer was investigated. Airflow velocity and direction were tested at different inlet areas, heights, and downstream horizontal distances using a three-dimensional ultrasonic anemometer. Analysis of variance (ANOVA) and regression modeling were applied to elucidate the effects of these three factors on airflow velocity, horizontal angle (θ), and elevation angle (Φ). The results showed that a stable alternating “primary jet–interaction zone” structure was formed in the spatial airflow field under all operating conditions, indicating that the fundamental airflow pattern was mainly governed by the sprayer layout. Varying the inlet area did not alter the basic airflow structure; however, the intensity and directional stability of the primary jets were significantly modified. Larger inlet openings produced higher airflow velocities, with a maximum near-field velocity of 19.7 m s⁻¹, whereas smaller inlet openings resulted in faster far-field attenuation and more pronounced diffusion. Increasing the inlet area caused the θ distribution peak to converge toward 0°, thereby improving axial coherence and directional stability. In contrast, decreasing the inlet area shifted Φ toward more negative values, with Φ reaching approximately −20° in the far field; moreover, far-field differences in Φ were more pronounced. Under the minimum inlet opening area condition (S1), the airflow velocity within the region 80–100 cm from the outlet can be stably maintained above 3 m/s, with a relatively uniform velocity distribution. This is beneficial for improving droplet deposition uniformity within the canopy and reducing droplet drift in non-target areas. Based on the experimental data, a regression model for mean airflow velocity was established (R² = 0.873), demonstrating good predictive performance and indicating that inlet-opening regulation is feasible. These findings provide a basis for airflow matching and spray-parameter optimization for different canopy structures. Full article

Neuroplacentology is an emerging field of research supporting that the placenta actively contributes to the fetal brain development through the release of bioactive molecules. Recent angiogenesis-focused data showed that prenatal alcohol exposure (PAE) disrupts inter-organ gene expression between the placenta and fetal cortex. The present study aimed to perform the first comprehensive and untargeted analysis of a murine placenta–cortex transcriptomic database of PAE. Gene lists from a recently NCBI-deposited PAE Placenta–Cortex transcriptomic database were analyzed using g:Profiler for unbiased functional profiling querying Gene Ontology, KEGG, and Reactome databases. Genes intersecting with cell–cell communication terms were submitted to STRING and ShinyGO analyses to identify enriched protein–protein interactions and pathways. Several ligand or receptor candidates were then validated by Western blot. g:Profiler revealed 21 enriched GO functional maps, seven KEGG pathways, and six Reactome pathways, of which 11 were related to cell-to-cell communication. STRING analysis exhibited substantial protein–protein interaction enrichments supporting that proteins belonging to the functional maps and pathways are biologically connected. Notably, 38 ligands or receptors from endocrine families including angiotensinogen, leptin, somatostatin, or PACAP were identified. Western blot analysis of protein candidates showed different validation patterns. In particular, the PACAP receptor family confirmed transcriptomic findings and revealed sex-dependent PAE-impacted expression profiles. The present study indicates that PAE is associated with alterations in the transcriptomic placenta–cortex expression profile, including changes in the expression ratios of several ligands and/or receptors implicated in key physiological pathways such as energy balance, vascular development, and neurogenesis. These transcriptomic associations suggest that altered placenta–fetal brain signaling at the gene expression level may be involved in alcohol-induced neurodevelopmental disorders, highlighting the need for future functional validation studies. Full article

Background and Clinical Significance: Phosphoglyceride crystal deposition disease (PCDD) is an extremely rare condition characterized by the deposition of phosphoglyceride crystals, occasionally forming tumor like lesions that present significant diagnostic challenges. Here, we report, to our knowledge, the first documented recurrent case of PCDD confined to the mandible, which clinically and radiologically mimicked a malignant bone tumor. Case Presentation: An 80-year-old female patient presented with a progressively enlarging mandibular mass, and imaging studies demonstrated an osteolytic lesion with cortical bone destruction and marked fluorodeoxyglucose uptake on positron emission tomography-computed tomography, raising a strong suspicion of malignancy. Histopathological examination revealed foreign-body granulomatous inflammation with characteristic crystal deposition, and the diagnosis of PCDD was definitively established through the combined use of gold hydroxamic acid staining, Raman spectroscopy, and ultrastructural analysis. Although surgical excision with curettage was initially achieved, local recurrence was observed 6 years later, indicating the potential for long-term disease persistence. In addition, a comprehensive literature review conducted in accordance with the PRISMA guidelines was performed to summarize previously reported cases of PCDD, with particular attention to anatomical distribution, radiological characteristics, recurrence patterns, and proposed pathogenic mechanisms. The review confirmed the extreme rarity of mandibular involvement and demonstrated that recurrence can occur apparently even after surgical treatment. Conclusions: This case underscores the importance of a multimodal diagnostic strategy integrating imaging, histopathology, and spectroscopic analyses for the accurate identification of PCDD and highlights the necessity of histopathological confirmation to prevent unnecessary aggressive treatment. Full article