Search Results (9,910)

Background/Objectives: The aim of the current study was to investigate the mechanistic hepatoprotective efficacy of selenium (SE) and chitosan-coated selenium nanoparticles (CS-SENPs) using a rat model induced by lipopolysaccharide (LPS). Methods: CS-SENP was prepared and characterized for particle size, polydispersity index (PDI), zeta potential, transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FTIR). Male albino rats (n = 40) were divided into four groups: control, LPS, SE, and CS-SENP. SE and CS-SENPs (5 mg/kg orally for 14 days) were given before LPS injection. Tissue architecture was assessed using histopathological analysis. HSP-47 and STEAP-3 protein expression levels were measured using ELISA, and oxidative stress markers were quantitatively evaluated. The expression of HO-1, TLR-4, STAT-3, TRAF-6, and IL-17A was measured using immunohistochemical analysis. Furthermore, HSP-90 expression was evaluated by immunofluorescence labeling. Results: CS-SENP characterization revealed uniform (PDI = 0.125 ± 0.04) nanoparticle size (108.54 ± 2.24 nm), with high zeta potential (+63.92 ± 6.287 mV), attributed to the CS layer, which was confirmed by FTIR and TEM as an electron-lucent halo enveloping the individual SENP cores. CS-SENPs significantly reduced lipid peroxidation (MDA) and restored glutathione (GSH) more effectively than SE. CS-SENPs improved redox (upregulated HO-1) and iron balance (downregulated STEAP-3), and also increased the anti-inflammatory effect (suppressed TLR-4, IL-17A, TRAF-6, and STAT-3). CS-SENPs showed superior antifibrotic efficacy (suppresses stress proteins, HSP-47 and HSP-90). Rats treated with CS-SENPs had nearly normal liver structure. Conclusions: The results concluded that CS-SENPs had superior and multi-targeted hepatoprotection against LPS-induced liver damage. Full article

The Tianfu Gas Field in the Sichuan Basin is a core block for the large-scale, economic development of Jurassic tight gas in China. The first sub-member of the first member of the Shaximiao Formation in the Zhongjiang Block hosts typical low-porosity and low-permeability tight sandstone reservoirs. Based on detailed field geological surveys and core observations, this study employed multiple technical methods, including cast thin sections, scanning electron microscopy, computed tomography (CT) scanning, and nuclear magnetic resonance (NMR) to investigate sedimentary microfacies' characteristics, analyze key reservoir properties (e.g., reservoir space types and pore structure), and clarify the main controlling factors of reservoir development. The results indicate the following: (1) The sedimentary period of the first sub-member of the first member of the Shaximiao formation (Es₁¹) was controlled by a subtropical humid climate, with widespread gray mudstones and bedding-parallel plant fossil fragments. The main sedimentary environment was a shallow-water delta front, where the underwater distributary channel microfacies was the dominant facies belt. (2) Reservoir lithology is dominated by lithic arkose and feldspathic litharenite, with low compositional and structural maturity. Residual primary intergranular pores are the dominant reservoir space type, followed by intragranular dissolved pores in feldspar and lithic fragments. (3) The pore structure is characterized by a small pore-throat radius, poor sorting, and strong heterogeneity. Reservoirs can be subdivided into three categories, with Types II and III being the main types developed in this block. (4) Underwater distributary channels of the shallow-water delta are the main occurrence of reservoir sand bodies. During the burial diagenetic stage, calcite and laumontite cementation and filling led to reservoir densification. Meanwhile, early-formed chlorite rim cement effectively protected primary pores by inhibiting grain compaction and quartz overgrowth. Superimposed with the dissolution and alteration of feldspar, lithic fragments, and other components by late acidic fluids, effective pores were further expanded. The synergistic coupling of these sand-controlling factors and the “densification–protection–alteration” diagenetic process jointly constitutes the formation mechanism of high-quality reservoirs. This mechanism can provide a reliable theoretical basis for the accurate prediction of reservoir “sweet spots” and the optimal selection of horizontal well targets in the Zhongjiang Block of the Tianfu Gas Field. Full article

This study examines the role of volatility mean reversion in option pricing and evaluates the performance of commonly used volatility estimators within a broad market context. Using a comprehensive dataset of end-of-day option chains for the 100 most actively traded U.S. equities from 2018 to 2023, we apply several established statistical techniques—including unit root tests, variance ratio analysis, Hurst exponent estimation, and GARCH modeling—to quantify the presence and strength of mean reversion in volatility. To assess the accuracy and practical usability of volatility metrics for option valuation, we compare realized volatility, GARCH-based forecasts, range-based estimators, and widely used implied volatility measures such as the VIX and daily implied volatility averages, benchmarking each against contract-specific implied volatility. The results indicate that more than 65% of the analyzed tickers exhibit statistically significant mean-reverting behavior, and that the 30-day average implied volatility consistently provides the most reliable predictive performance among the tested metrics, while range-based estimators perform poorly when applied to end-of-day data. Finally, backtests of six delta-neutral option strategies informed by these findings did not yield consistent profitability or statistically significant outperformance, suggesting that although volatility mean reversion is measurable, its direct application to systematic trading remains challenging. Full article

Synergistic diagenetic evolution of sandstones and shales significantly impacts the quality of associated tight oil and shale oil reservoirs. Using integrated petrographic (thin sections, fluorescence thin sections, scanning electron microscopy with energy dispersive spectroscopy), mineralogical (X-ray diffraction), geochemical (stable carbon–oxygen isotopes, electron microprobe), organic petrologic, and petrophysical analyses, combined with basin burial and thermal history reconstruction, this study investigates the mechanisms and processes of synergistic diagenesis in the tight sandstone-shale assemblages of the 7th and 8th Members of the Yanchang Formation (Middle-Late Triassic) in the western Zhidan area, Ordos Basin, China. Controlled by basin evolution, the interbedded sandstones and shales, under shared burial-thermal conditions, exhibit strong synergy in four coupled processes: compaction, clay mineral evolution, shale fluid expulsion coupled with sandstone carbonate cementation, and shale hydrocarbon expulsion coupled with sandstone secondary porosity generation. This “fluid supply-response modification” relationship strongly influences diagenetic pathways and reservoir space evolution in sandstones, leading to variable reservoir quality among different sandstone-shale assemblages. Thicker-bedded sandstones interbedded with thinner-bedded shales represent potential targets for high-quality tight sandstone reservoirs. These findings provide a possible theoretical and methodological basis for identifying high-quality tight sandstone reservoirs in lacustrine-deltaic sandstone-shale assemblages. Full article

Drought is an increasing threat to livelihood security and sustainable development in the Vietnamese Mekong Delta (VMD), particularly in Kien Giang Province. This study examines the spatiotemporal dynamics of meteorological drought from 1992 to 2024 using daily rainfall data from 10 rain gauges. The Standardized Precipitation Index (SPI) was calculated at 3-, 6-, and 12-month timescales to assess short-, medium-, and longer-term precipitation deficits across the province. The results show that the most severe drought events were concentrated in the most recent decade, especially during the 2015–2016 and 2019–2020 dry seasons. Spatial analysis identified clear drought hotspots: the northern coastal zone, including Ha Tien and Hon Dat, exhibited the strongest long-timescale drought signal, while central inland areas such as Go Quao experienced more frequent short-timescale drought conditions. A significant negative relationship was also observed between SPI and the Oceanic Niño Index (ONI), indicating that El Niño conditions intensified drought severity, particularly in coastal areas. These findings highlight the need for spatially differentiated drought adaptation in Kien Giang Province, with stronger emphasis on water storage and water-use efficiency in inland districts and on early warning and integrated drought–salinity management in high-risk coastal zones. Full article

Water level fluctuations in reservoir areas subject bank slopes to intense wet–dry cycles (WDCs), compromising rock mass stability. This study investigates the macro–meso damage evolution of yellow sandstone from the Wudongde Reservoir. Specimens subjected to 0–20 WDCs were analyzed using nuclear magnetic resonance (NMR) alongside Brazilian splitting, uniaxial, and triaxial compression tests. Results indicate that porosity increases linearly with WDC, rising from 6.12% to 17.61% after 20 cycles, driven by the transformation of micropores into macropores. Macroscopic mechanical parameters, particularly tensile strength and cohesion, exhibit significant exponential and sharp decay, respectively, while the internal friction angle remains relatively stable. Notably, increasing confining pressure effectively mitigates WDC-induced deterioration by inhibiting microcrack propagation. The damage mechanism is primarily attributed to the dissolution of clay binder and uneven mineral swelling/shrinkage, whereas the rigid mineral skeleton remains largely intact. These findings provide a theoretical basis for quantifying rock damage and predicting slope stability in complex hydrological environments. Full article

Alluvial plains in the marginal zone of the monsoon system are sensitive to the climate–hydrology interaction. However, long term, high-resolution sedimentary records remain scarce in the Songnen Plain of Northeast China. This limited our understanding of the paleoclimate–paleohydrology coupling evolution over glacial–interglacial cycles. A 50.6 m continuous core was retrieved from the western Songnen Plain. The age–depth model and wavelet transform spectrum showed sedimentary continuity from ~885 ka B.P. (the late Early Pleistocene) to ~6 ka B.P. (the early Holocene), with no major hiatuses exceeding orbital resolution. Grain size analyses revealed 18 microfacies, which were synthesized into two major evolutionary cycles: a fan-delta front cycle (dominated by subaqueous mouth bars and distributary channels) and a fan-delta plain cycle (characterized by intertributary bays, floodplain lakes/swamps, and crevasse splays). The absence of pro-delta facies and the sediment succession record the oscillatory shrinkage of the Songnen paleolake. The pulsed enhancements of hydrodynamic energy, marked by grain size coarsening, coincide with major glacial–interglacial transitions (MIS 20/19, 18/17, 16/15, 14/13, 8/7, 6/5, 4/3, and 2/1), whereas fining grain sizes dominate warm interglacial periods (MIS 11, 9, 7, 5, 3, 1). These patterns are sensitive response of the alluvial plain to orbital-scale climate change. Cold–arid glacial background promoted vegetation loss and hydrological instability, and warm–humid interglacial background favored low-energy hydrological condition. This study demonstrates that the regional alluvial evolution was primarily controlled by global ice-volume fluctuations through variability of the East Asian summer monsoon. This study provides a reference for the muti-scale climate–hydrology coupling mechanism study in the northern marginal zone of EASM and highlights the importance of alluvial sediment succession in paleo-research. Full article

The qEEG findings of subjects with Down syndrome (DS) have not been described in the context of bipolar montage. Resting-state EEG (rsEEG) with a bipolar montage was performed in 22 young adults (26.0 ± 1.2 years) with DS but without psychiatric or neurological pathology and matched control subjects of the same sex and age, and the results were conventionally and numerically analyzed. Channels were grouped into frontal, parieto-occipital, and temporal lobes. For every channel, the power spectrum was calculated and used to compute the area for the delta, theta, alpha and beta bands and was log-transformed. Shannon’s spectral entropy (SSE) and coherence by bands were computed. Finally, we also calculated the peak frequency distribution of the alpha band. qEEG revealed alterations in the rsEEG that were not detected visually. Subjects with DS showed a significant generalized increase in the power of the delta and theta bands, along with a decrease in the power of the alpha band in the posterior half of the scalp. This alpha activity also exhibited features corresponding to older euploid subjects, showing interhemispheric asynchrony in one-third of the individuals. The beta band power was significantly increased in the frontal lobes and adjacent regions, such as the parietal and mid-temporal regions. Individuals with DS showed a generalized decrease in parieto-occipital synchronization associated with intelligence quotient. Left temporal synchronization was also lower. The synchronization of specific channel pairs was greater in subjects with DS in the frontal lobe and much lower in the occipital and temporal regions. These results indicate that alterations in band structure and synchronization in subjects with DS are highly specific and can aid in the clinical evaluation of these individuals. Full article

China’s stringent clean air policies have substantially reduced nitrogen oxides (NO_x) emissions, leading to a general decline in nitrogen dioxide (NO₂). However, surface ozone (O₃) pollution remains severe, creating a complex challenge due to the non-linear relationship between O₃ and its precursors. To disentangle the drivers behind these trends, this study quantifies the impacts of interannual variations in top-down constrained NO_x emissions on surface NO₂ and O₃ concentrations from 2014 to 2021 across mainland China and five national urban agglomerations. We employed the WRF-CMAQ model with a fixed-emission simulation approach, using an observationally optimized NO_x emission inventory derived from the assimilation of surface NO₂ measurements. Results reveal that NO₂ reductions were predominantly emission-driven (>80% post-2017), with declines most pronounced in winter. A strong linear consistency was found between interannual changes in top-down NO_x emissions and attributed NO₂ concentration variations, validating the methodology. In contrast, O₃ responses to NO_x reductions were spatially and seasonally heterogeneous, reflecting a non-linear photochemical regime. In major urban agglomerations (e.g., Beijing–Tianjin–Hebei (BTH), Yangtze River Delta (YRD), Pearl River Delta (PRD)), NO_x reductions post-2018 showed limited effectiveness in mitigating summertime O₃ and even increased O₃ in spring and autumn, indicating a prevalent VOC-sensitive regime where NO_x reduction can disinhibit O₃ formation. Conversely, certain provinces (e.g., Anhui, Shanxi, Jilin) exhibited O₃ decreases, suggesting a NO_x-sensitive regime. The area benefiting from NO_x reductions expanded steadily in summer after 2017 but not in other seasons. This study confirms the efficacy of NO_x-focused policies for reducing primary NO₂ pollution but highlights that mitigating persistent O₃ requires a strategic shift to synergistic, region-specific control of volatile organic compounds alongside NO_x, informed by local chemical sensitivity. Full article

In this paper, we introduce new two-sided Ostrowski-type inequalities on arbitrary time scales. Using the delta derivative and delta integral operators, we obtain explicit bounds for the deviation of a function value from the mean delta integral, under the assumption that the delta derivative is bounded between two integrable functions. With additional monotonicity conditions on the bound functions, further refinement of the obtained estimates is possible. The results recover the classical continuous Ostrowski inequality, as well as its discrete and quantum counterparts on $\mathbb{Z}$ and $q^{\mathbb{Z}}$, as special cases. Full article

Introduction: SLC6A1-related neurodevelopmental disorder (SLC6A1-NDD) is an epileptic encephalopathy linked to mutations in the SLC6A1 gene and is characterized by early-onset seizures and developmental delays. Despite the growing recognition of SLC6A1 as a major cause of early-onset epilepsy, the electrophysiological changes associated with the disorder remain inadequately characterized. This study aims to identify electrophysiological biomarkers of SLC6A1-NDD by characterizing EEG delta power using automated tools, EEGLAB (v2023.1) and Persyst 13, exploring age- and state-related effects. Methods: We analyzed EEG recordings from 20 patients with SLC6A1-NDD and 20 neurotypical age- and sex-matched controls using EEGLAB and Persyst, quantifying delta power and related metrics. The Wilcoxon signed-rank method tested for differences between patients and controls, area under the curve (AUC) values evaluated patient classifier models, and Pearson’s correlation assessed concordance between EEGLAB and Persyst. Results: Patients with SLC6A1-NDD exhibited significantly elevated delta power (19.4 ± 4.1) compared to controls (14.2 ± 3.0; p < 0.001). The mean delta power showed an age-dependent increasing trend in patients (b = 0.5), contrasting with a decline in controls (b = −1.0; p < 0.001). In Persyst, the frequency of delta activity above an optimized threshold best differentiated patients from controls in wake epochs (AUC = 0.93). Concordance between EEGLAB and Persyst was one-to-one but with moderate variability (R² = 0.644; p < 0.001). Conclusions: Elevated delta power is a notable feature of SLC6A1-NDD. Cross-platform comparison demonstrates the feasibility of quantitative EEG analysis, while imperfect concordance highlights the need for pipeline standardization. Future work should validate these findings in larger cohorts and, as suitable reference data emerge, benchmark delta power metrics against age-matched children with other developmental and epileptic encephalopathies. Full article

The urban ecosystem constitutes a complex adaptive system comprising interdependent subsystems—environment, population, infrastructure, public services, environmental governance, and socio-economic factors. Conventional system dynamics (SD) modeling relies on expert-derived causal assumptions, which have limitations in objectivity, transferability, and adaptability. To solve these, this study develops a data-driven SD modeling framework that infers causal structures from time-series data of 38 sustainability indicators. The framework integrates multiple causal inference techniques to identify causal relationships among variables, then systematically identifies stock variables and constructs an SD simulation model. Applying it to panel data from 41 cities in China’s Yangtze River Delta (2013–2022), the study characterizes the causal network topology, interaction patterns between subsystems, dominant feedback loops, and temporal evolution trajectories of key stock variables. Results show: (1) There is significant cross-city variation in causal network structure due to differences in urban development and institutional configurations; (2) Environmental conditions are the most frequently affected terminal node with an average normalized causal strength of 0.277, higher than other subsystems; (3) Several cross-subsystem positive and negative feedback loops are identified, highlighting potential path dependencies and intervention-sensitive nodes for sustainable urban transitions. This study provides a replicable, comparable, and scalable framework for urban sustainable development analysis, offering data-driven support for smart city management and policy formulation. Full article

Artificial seawater lakes constructed in estuarine environments are highly susceptible to the intrusion of water containing high concentrations of suspended sediment, which can degrade water quality and threaten ecosystem stability. To clarify the settling mechanisms and sedimentation efficiency under high-turbidity conditions, this study investigated the Baishawan Artificial Lake in the Jiaojiang Estuary, eastern China, through field observations, controlled still-water sedimentation experiments, and a multi-particle size sedimentation efficiency model. Field measurements revealed significant spatiotemporal variability in suspended sediment concentration (SSC), with higher SSC during spring tides than neap tides and a spatial gradient decreasing from the near-estuary zone to the artificial lake and offshore waters. Grain-size analysis showed that suspended sediment was dominated by clay and silt (>98%). Laboratory experiments indicated a two-stage settling process characterized by rapid initial sedimentation followed by gradual stabilization; under high concentration (1.32 kg/m³), SSC decreased by about 85% within 40 min due to concentration-enhanced flocculation, whereas under low-concentration conditions (0.24 kg/m³) approximately 14 h were required to reach the target concentration of 0.01 kg/m³. Model validation demonstrated that the multi-component sedimentation model effectively reproduced the temporal attenuation of SSC. Model application further suggested that when the initial SSC was 0.70 kg/m³ and the water depth was 5.7 m, the sedimentation tank could reduce the SSC to 0.01 kg/m³ within about 16–17 h, with an estimated annual sedimentation volume of ~65,000 m³ and a recommended dredging interval of five years. These results provide quantitative guidance for sedimentation tank operation and sediment management in estuarine artificial lakes and other high-turbidity coastal environments. Full article

Background: Subchondral cysts at the ulnar corner of the lunate are frequently encountered in patients with distal radius fractures. We hypothesized that the presence of these lunate subchondral cysts may be associatedwith decreased cortical bone density due to limited load translation. Consequently, this could lead to lunate fossa collapse and increased ulnar variance following fracture fixation. Methods: A retrospective analysis was performed on 176 patients who underwent open reduction and internal fixation using the Double-tiered Subchondral Support (DSS) procedure between May 2014 and June 2017. Twenty-eight patients identified with lunate subchondral cysts on preoperative CT scans were selected as the study group. A control group of 28 patients without cysts was selected using matched-pair analysis, controlling for gender, age, fracture classification, and follow-up period. Results: The mean change (delta) in ulnar variance was 0.191 mm in the cyst group, which was less than the 0.233 mm observed in the control group; however, this difference was not statistically significant (p = 0.557). Regarding ulnolunate distance, the cyst group showed a mean change (delta) of 0.991 mm, while the control group showed a change of 1.123 mm. This difference was also not statistically significant (p = 0.681). Conclusions: Although it was hypothesized that lunate subchondral cysts might limit load translation to the radius and compromise cortical bone density—potentially affecting fracture healing and the maintenance of reduction—our statistical analysis did not support this hypothesis. The presence of lunate subchondral cysts did not significantly increase the risk of lunate fossa collapse or ulnar variance progression compared to the control group. Full article

Intrabasinal low uplifts in lacustrine rift basins are key targets for sedimentological and petroleum geological research, as they can act as local source areas and exert critical controls on intrabasinal “source-to-sink” systems. Due to the discontinuous sediment supply, these systems often demonstrate the subtle and intermittent nature, and their roles in the development of depositional systems are usually overlooked. To clarify the controlling effect of intrabasinal local provenances on sedimentary system evolution, this study reconstructed the dynamic tectonic evolution of the Weixinan Low Uplift in the Beibuwan Basin, and systematically analyzed its control on “source-to-sink” systems and sedimentary filling using integrated high-resolution 3D seismic, core, well logging and geochemical data. Our results demonstrate that the activity of Fault 3 dominated the paleogeomorphic evolution of the Weixinan Low Uplift and its surrounding areas, which further governed the spatiotemporal development of the “source-to-sink” system and the distribution of sedimentary systems, with distinct evolutionary stages as follows: During the Ls2 Member stage (48.6–40.4 Ma), Fault 3 was inactive, the Weixinan Low Uplift was manifested as a gently dipping subaqueous slope under the influence of regional lacustrine transgression, and only small-scale braided river deltas were developed on the slope belt with weak sediment supply from the Qixi Uplift. During the Ls1 Member stage (40.4–33.9 Ma), the Ls13 Sub-member stage (lower Ls1 Member stage) was characterized by initiation of Fault 3 with segmented activity, triggering the formation of the Eastern Sub-sag of the Haizhong Sag and subaqueous uplift of the Weixinan Low Uplift; clastic sediments from the central Qixi Uplift were transported northeastward, developed braided river deltas and large-scale basin-floor lacustrine fans. In the Ls12 Sub-member stage (middle Ls1 Member stage), Fault 3 continued to propagate and was gradually linked, leading to further uplift of the Weixinan Low Uplift and expansion of the Haizhong Sag; Clastic materials from the central Qixi Uplift were almost entirely trapped in the Eastern Sub-sag of the Haizhong Sag. During the Ls11 Sub-member stage (upper Ls1 Member stage), further intensification of Fault 3 activity caused the Weixinan Low Uplift to be subaerially exposed and evolve into an intrabasinal local provenance, which supplied clastic sediments to surrounding sags and developed braided river deltas on the gentle slope belts and small-scale lacustrine fans on the lower slope. This study demonstrates that the tectonic evolution of the Weixinan Low Uplift has induced prominent changes in the basin paleogeomorphology, which in turn triggered dynamic shifts in the provenance and sediment transport pathways, and thus gave rise to complex local “source-to-sink” systems and depositional styles. Full article