Search Results (676)

Deepwater shallow gas sediments and the weakly consolidated overburden are sensitive to depletion-induced effective stress redistribution. Since deepwater shallow gas has only recently begun to be treated as a commercially available natural gas resource, it lacks models to quantify the coupled flow and geomechanical behaviors in such environments. In this study, we propose a semi-analytical model for a shallow gas layer and its overburden sediments, where pore pressure evolution is described by vertical transient diffusion and the stress response is represented by an OCR-dependent (overconsolidation ratio-dependent) in situ stress field with depletion-induced effective stress increments. Pre-yield compressibility is characterized by a stress-dependent nonlinear elastic law, and post-yield deformation is approximated by a Mohr–Coulomb-based yield-controlled plastic correction for engineering purposes. The formulation is used in the base case and during a parametric sensitivity analysis. In the base case, the final settlement is 0.597 m, of which 45.3% is elastic and 54.7% is plastic. The sediments begin to yield after approximately 115 d of production, and the final yielded-thickness fraction reaches 0.268. The sensitivity analysis shows that friction angle, maximum drawdown, gas-layer thickness, and OCR magnitudes predominantly affect the final settlement and yielded-thickness response, while gas-layer permeability has an insignificant effect. Furthermore, the comparison reveals that the depletion timescale governs the stress evolution rate, while depletion pressure drawdown magnitude dictates deviatoric stress evolution and long-term settlement. Considering the engineering condition for the development of typical deepwater shallow sediments, the feasible production parameters should be in the low-to-moderate drawdown and slow depletion range. A practical operating window is approximately 3.6~4.0 MPa maximum drawdown with a depletion timescale of about 340~400 d. This study can provide quantitative insights into the potential commercial production of gas layers in deepwater shallow sediments. Full article

Reliable estimates of volumetric water content at field capacity (θFC) are important inputs for irrigation scheduling because θFC contributes to the estimation of plant-available water, depletion thresholds, and refill targets. In irrigated systems, θFC is therefore an operational decision variable rather than a fixed soil property. However, θFC varies systematically across estimation methods, introducing uncertainty into irrigation management. This study evaluated method-dependent differences in θFC for irrigated tropical soils in the Roldanillo–Unión–Toro agricultural irrigation district (Valle del Cauca, Colombia). Field capacity was estimated at 42 sampling points (0–0.10 m depth) using four methods: Mariotte bottle (MB), filter paper (FP), a pedotransfer function (PTF), and the Richards pressure plate method (RPP). The RPP method was used as an operational reference for comparative purposes, not as an absolute representation of true FC. Agreement and bias were assessed using descriptive statistics, error metrics, regression, Bland–Altman analysis, and texture-stratified comparisons. RPP θFC averaged 39.37% (range: 29.85–46.41%), whereas MB, FP, and PTF produced higher mean values of 42.66%, 44.26%, and 46.38%, respectively. Relative to RPP, mean error and root mean square error increased from MB (3.29% and 5.21%) to FP (4.89% and 8.16%) and PTF (7.01% and 10.82%). Disagreement also varied with soil texture. These results show that low-cost θFC methods are not directly interchangeable with RPP measurements in the evaluated surface layer. Because θFC is commonly used in irrigation calculations, the observed method-dependent differences may affect the estimation of depletion thresholds and refill targets if surface-layer values are extrapolated without local validation. Overall, surface-layer θFC in the Roldanillo–Unión–Toro irrigation district was strongly method-dependent, highlighting the need to account for method-related uncertainty before using alternative θFC estimates as inputs for irrigation decision support. Full article

Wildfires severely disrupt soil nitrogen (N) cycling, yet the mechanisms driving this disruption in fragile karst forest ecosystems remain poorly understood. We investigated how wildfires affect soil N transformation dynamics and the microclimatic drivers of these dynamics in a karst forest. Using an in situ paired burned versus unburned plot design, we evaluated post-fire soil physicochemical properties, N fractions, and N-acquiring enzyme activities in the 0–10 cm soil layer. Wildfires significantly deteriorated the soil microenvironment, increasing mean soil temperature by 9.93% and bulk density by 36.66%, while sharply reducing soil water content, porosity, and saturated hydraulic conductivity. Consequently, the fires severely depleted total and organic soil N pools. Furthermore, N-acquiring enzymes (urease, protease, nitrate reductase, and nitrite reductase) initially declined in activity before gradually recovering. Notably, partial least squares structural equation modeling (PLS-SEM) revealed a fundamental shift in the drivers of nitrogen transformation. In unburned soil, abiotic climatic factors regulated N dynamics. After wildfire, enzyme-mediated biological processes controlled N dynamics, and these processes were constrained by altered soil physics. Restoring soil physical structure and stimulating enzymatic mineralization are therefore critical, rate-limiting steps for the recovery of soil N reservoirs in fire-prone karst landscapes. Full article

A highly sensitive ppb-level resistive H${}_2$ gas sensor was fabricated based on Pt/PtO and Pd/PdO${}_x$ co-decorated WO${}_3$ nanofibers prepared via electrospinning and calcination. The optimized sensor based on 2 at% Pt–2 at% Pd co-decorated WO${}_3$ nanofibers exhibited reliable detection toward 100 ppb H${}_2$ at an optimized operating temperature of 170 ${}^{\circ }$C. Upon 2 at% Pd decoration, the response of the WO${}_3$-based sensor increased from 1, corresponding to almost no response, to 55 (R${}_a$/R${}_g$) toward 100 ppm H${}_2$. Further introduction of 2 at% Pt reduced the optimal operating temperature of the 2 at% Pd-decorated WO${}_3$-based sensor from 200 ${}^{\circ }$C to 170 ${}^{\circ }$C and enhanced the response by approximately twofold. The optimal sensor exhibits excellent linear response characteristics, high selectivity, good response repeatability, and long-term operational stability. The enhanced sensing performance is attributed to the catalytic capability and possible spillover-related effects of Pd/PdO${}_x$ and Pt/PtO toward H${}_2$/O${}_2$, as well as depletion-layer modulation induced by the heterostructures between Pt/PtO and WO${}_3$, and Pd/PdO${}_x$ and WO${}_3$. These synergistic catalytic and electronic sensitization effects collectively contribute to the high sensitivity toward H${}_2$. These results indicate that the proposed resistive H${}_2$ sensor holds significant potential for practical hydrogen-sensing applications. Full article

Controlled delivery using nanoparticle-based systems has attracted considerable attention; however, achieving cell-type specificity remains a major challenge. To address this issue, we focused on the intrinsic cell tropism of viruses. The hepatocyte tropism of hepatitis B virus (HBV) is mediated by interactions between its large envelope protein (L protein) and host factors, including the sodium taurocholate cotransporting polypeptide (NTCP). In this study, we explored viral-like secretory vesicles (VLSVs) displaying HBV spike proteins as a virus-inspired vesicle platform for hepatocyte targeting. We previously established a method for producing VLSVs from HBV L- and S-expressing HEK293T cells. In the present study, we developed an improved protocol using exosome-depleted fetal calf serum and optimized ultracentrifugation, resulting in VLSVs with comparable particle numbers and sizes but approximately tenfold higher protein content per particle. VLSVs were concentrated using a two-layer sucrose cushion, labeled with DiI, and purified by sucrose density gradient ultracentrifugation. We evaluated DiI uptake in hepatocyte-derived cells (HepG2 and Huh7), non-hepatic cells (MDA-MB231, H1299, HeLa, and Vero), and NTCP-overexpressing HepG2 cells. VLSVs showed preferential uptake in the following order: NTCP-overexpressing HepG2 > HepG2 > Huh7 > non-hepatic cells. Furthermore, removal of the N-terminal Flag tag from the L protein enhanced hepatocyte-associated uptake, suggesting the importance of preserving the native structure of the preS1 domain. While vesicle characterization and mechanistic validation remain to be further investigated, these findings provide a proof-of-concept for a virus-inspired vesicle platform exhibiting preferential uptake in hepatocyte-derived cells. Full article

The gastrointestinal (GI) barrier is a highly coordinated, multilayered defence system that maintains intestinal homeostasis by separating the luminal microbiota from the internal milieu. In liver cirrhosis, this barrier undergoes profound structural and functional disruption, emerging as a central driver of bacterial translocation and infection-related complications. Among these, spontaneous bacterial peritonitis (SBP) represents a major determinant of morbidity, mortality, and disease progression. Barrier failure in cirrhosis is not attributable to a single defect but results from the convergence of multiple interconnected mechanisms. Structural alterations include disruption of epithelial tight junctions and deterioration of the mucus layer, leading to increased intestinal permeability and loss of spatial compartmentalisation. These changes are compounded by microbial dysbiosis, characterised by reduced diversity, depletion of short-chain fatty acid-producing taxa, and expansion of pathobionts. In parallel, cirrhosis-associated immune dysfunction impairs both mucosal and systemic antimicrobial defences, while gut–vascular barrier disruption facilitates systemic dissemination of bacteria and microbial products. The resulting increase in bacterial translocation plays a pivotal role in the pathogenesis of SBP and contributes to systemic inflammation, circulatory dysfunction, and acute decompensation. Importantly, this process establishes a self-amplifying pathogenic loop in which barrier dysfunction, dysbiosis, and immune dysregulation mutually reinforce each other. Recent advances have identified key molecular pathways involved in barrier regulation, including bile acid–FXR signalling and microbiome-derived metabolites, providing novel targets for therapeutic intervention. While current management relies largely on antibiotics and supportive care, emerging strategies aim to restore barrier integrity and modulate the gut–liver axis. A deeper understanding of GI barrier dysfunction offers new opportunities to prevent bacterial translocation and improve clinical outcomes in patients with liver cirrhosis. Full article

The Chang 7₃ sub-member of the Yanchang Formation in Ordos Basin represents an important layer of uranium-rich source rocks. Exploring the genesis of phosphorus-bearing minerals and the mechanism of uranium enrichment are of great significance for deciphering basin evolution and uranium mineralization. The geochronology of phosphorus-bearing minerals and uranium enrichment mechanisms is investigated by using electron microscopy, laser ablation inductively coupled plasma mass spectrometry, U-Pb geochronology, and geochemical analysis. Results indicate the following: (1) The formation of phosphorus-bearing minerals can be divided into two independent stages. During the early sedimentary-diagenetic stage, influenced primarily by volcanic activity, volcanic ash tends to serve as the main source of both phosphorus and uranium. The coupling of high primary productivity and organic matter decomposition synergistically contributes to promoting apatite precipitation. During the Late Cretaceous hydrothermal diagenesis stage, the U-Pb isotopic systems of apatite were reset, yielding ages of 84 ± 2 Ma and 68 ± 1 Ma. This event also significantly modified the REE distribution patterns, resulting in flattened chondrite-normalized patterns and obvious LREE depletion. (2) Uranium enrichment in phosphorus-bearing minerals, which is closely associated with their formation, occurred through a two-stage process. During the sedimentary stage, U⁶⁺ was reduced to U⁴⁺ and incorporated into the mineral lattice via isomorphous substitution for Ca²⁺ or adsorbed onto mineral surfaces through complexation. Whereas the subsequent hydrothermal diagenesis stage led to further uranium enrichment as hydrothermal fluids introduced additional U⁶⁺, which was reduced to U⁴⁺ under anoxic conditions and incorporated into the apatite lattice via isomorphous substitution for Ca²⁺ or precipitated as discrete uranium minerals. Full article

Accurate production forecasting of oil wells is of great significance for reservoir management, production optimization, and investment decisions. However, complex subsurface dynamics and sudden operational interventions frequently break the temporal symmetry of production sequences, generating highly asymmetric data distributions. Standard deep sequence architectures often suffer from severe phase lag and limited adaptability when modeling such asymmetric regime transitions. To resolve these bottlenecks, we introduce the Signature-Weighted Kolmogorov–Arnold Network with Gated Recurrent Units (SigKAN-GRU). The architecture replaces static node activations with adaptive edge–spline mappings, enabling robust approximation of asymmetric nonlinearities. Path signatures compress high-order asymmetric temporal trajectories into invariant geometric features, a learnable gating kernel filters critical variations, and a final GRU layer enforces explicit sequential memory. This integration bridges long-term depletion trends with abrupt asymmetrical perturbations while maintaining structurally controlled complexity and an interpretable decomposition of nonlinear response and temporal weighting. Validated on two real-world wells with contrasting data characteristics, SigKAN-GRU consistently minimizes absolute error metrics and phase distortions against prevailing baselines. In addition, event-sensitive evaluations further confirm its reliability in peak regions and abrupt shock intervals. The resulting framework translates erratic historical data into robust deterministic forecasts, offering a rigorous quantitative tool for field-level reservoir optimization. Full article

The cement industry has been seeking strategies to ensure the circularity of materials through the incorporation of solid waste into its processes, driven by the environmental challenges associated with cement production, such as high CO₂ emissions and resource consumption. In this context, marble residue (MR) has been investigated for application in cementitious materials, including as a partial cement substitute, which also mitigates MR deposition as an inert waste in landfills. Although its technical feasibility has shown promising results, environmental justification is still necessary to validate this technology. This research presents a Life Cycle Assessment (LCA) of MR as a substitute for limestone filler in ternary cement production, promoting circular economy principles. The environmental impacts of three formulations were compared: Ordinary Portland Cement (OPC), used as the reference; limestone calcined clay cement (LC³), composed of calcined clay and limestone filler; and LC³-R, which incorporates 15% MR in place of limestone filler. The cradle-to-gate LCA included raw material extraction through to cement production, using OpenLCA (v2.3) and the Ecoinvent database (v3.6). The impact categories analyzed included abiotic depletion (ADP), abiotic depletion of fossil fuels (ADP-ff), global warming potential (GWP 100a), ozone layer depletion (ODP), human toxicity potential (HTP), and acidification potential (AP). Results showed that LC³-R had the lowest environmental impacts, with reductions up to 39% compared to OPC and 11% compared to LC³. A sensitivity analysis was conducted for environmental and economic dimensions to assess the influence of MR transportation distances in the LC³-R context. The LC³-R formulation remained environmentally viable up to an additional 400 km compared to OPC, and up to 100 km compared to LC³, being also competitive in the economic dimension. The results highlight the benefits of incorporating marble residue into LC³ cement, contributing to environmental impact reduction and promoting resource efficiency within a circular economy approach. Full article

Quantum Key Distribution (QKD) enables two parties to securely share encryption keys by leveraging the principles of quantum mechanics, offering protection against eavesdropping. In practical implementations, QKD systems often rely on a layered architecture where a key manager stores secret key material in a buffer and delivers it to higher communication layers as needed. However, this buffer can be depleted under high demand, requiring efficient replenishment strategies that minimize resource waste. Given the importance of optimizing time and resources in quantum cryptography protocols, we introduce a variable-length adaptation of the BB84 protocol designed to meet user-defined output key length constraints in non-ideal scenarios. We present a method for dynamically configuring the protocol’s initial parameters to generate secret keys of a desired length. To validate our approach, we developed simulation tools to model general QKD networks and discrete-variable protocols. These tools were used to implement and evaluate our strategies, which were developed within the BB84 framework but can be extended to other QKD protocols under reasonable assumptions. The results highlight their usefulness in optimizing quantum resource usage and supporting key management, contributing to the long-term goal of scaling and strengthening secure quantum networks. Full article

Water scarcity is a critical constraint to sustainable agricultural production in arid and semi-arid regions. This study evaluated the effectiveness of subirrigation controlled drainage (SCD) systems in improving water use efficiency, soil conditions, and productivity of Egyptian clover (Trifolium alexandrinum L.) over two consecutive growing seasons (2022–2024). Three drainage treatments were investigated: subirrigation controlled drainage with water table depths of 0.4 m (SCD-0.4) and 0.8 m (SCD-0.8), and conventional free drainage at 1.2 m (SFD-1.2). The results demonstrated that SCD significantly reduced irrigation water requirements, achieving water savings of up to 27% under SCD-0.4 compared with conventional drainage. The shallow water table enhanced groundwater contribution to crop evapotranspiration, reaching over 40%, which improved soil moisture availability and reduced soil water depletion. Consequently, SCD-0.4 increased fresh and dry biomass yields by approximately 18% and significantly improved water productivity and irrigation water productivity. However, controlled drainage led to increased soil salinity due to reduced leaching, particularly in upper soil layers. Economic analysis revealed that SCD-0.4 achieved the highest net returns and water use profitability. Overall, controlled drainage at shallow depths represents an effective strategy to enhance water productivity, crop yield, and economic efficiency, although long-term salinity management must be considered for sustainable implementation. Full article

Finite element modeling (FEM) of hybrid bonding stacks for high-density 3D integration suffers from excessive computational load and prohibitive simulation time. To address this critical technical bottleneck, this paper proposes an analytical lumped-distributed equivalent circuit model based on multi-layer structures. The model incorporates both redistribution layer (RDL) parasitics and metal–insulator–semiconductor (MIS) depletion effects for comprehensive signal integrity analysis. Frequency-dependent RLGC electromagnetic parameters were extracted from through-silicon via (TSV) and RDL interconnects. These parameters were numerically calculated using MATLAB R2020a to construct the equivalent circuit model in ADS. The model was subsequently validated against COMSOL finite element simulations. The results demonstrated that the proposed methodology achieved maximum deviations below 5% for all S-parameters in double-layer structures. For 5-layer stacks, errors were controlled within 10% across the 0–40 GHz frequency range. Computation time was reduced from several minutes to seconds. The proposed equivalent circuit method significantly reduces computational time while maintaining accuracy, providing an efficient simulation methodology for signal integrity analysis and verification of hybrid bonding stack structures. Compared to existing single-layer models, this work extends the modeling approach to multi-layer hybrid bonding stacks while comprehensively accounting for both RDL parasitics and MIS depletion effects, addressing a critical gap in the current state of the art. Full article

Addressing the problem of limited methane (CH₄) recovery degree under different production conditions in a target low-permeability carbonate gas reservoir, this study intends to further investigate the effect of carbon dioxide (CO₂) injection on enhanced gas recovery (EGR). A group of long-core physical simulation experiments of CO₂ injection for EGR was adopted. Field injection–production parameters were converted to laboratory conditions through similarity criteria to simulate the actual production process of gas wells. Systematic experiments on CH₄ depletion and CO₂ displacement were carried out under different irreducible water saturation, gas injection timing pressure and injection rates. The influence laws of each key parameter on the CO₂ breakthrough time and CH₄ recovery degree were analyzed emphatically, and the optimal injection–production scheme was obtained. For the target low-permeability carbonate gas reservoir (permeability < 1 mD), the optimal CO₂ injection scheme is as follows: for layers with medium to high irreducible water saturation (≥40%), CO₂ injection at a rate of 36,000 m³/d per well after the end of stable production (formation pressure > 7.38 MPa) can increase the CH₄ recovery degree by 3–5%. This study provides experimental support for the optimization of CO₂ injection schemes for enhanced recovery in gas reservoirs and the adjustment of gas reservoir development strategies under different irreducible water saturation conditions. Full article

Groundwater level (GWL) variations in the arid regions of Northwest China are driven by both natural processes and human activities. Identifying causal links between hydrological variables is fundamental to understanding groundwater evolution and conducting dynamic simulations. This study integrates the Mann–Kendall test, Seasonal-Trend decomposition using Loess, and the Peter and Clark Momentum-threshold and Momentary Conditional Independence (PCMCI) causal inference to analyze GWL variation characteristics and causal response processes across seven sub-basins in the Tarim Basin using multi-source remote sensing data. Results show an overall decline in GWL, primarily in the north-central part of the basin, with the Kaidu–Konqi River Basin reaching a maximum rate of 0.51 m/year. The trend components reveal localized depletion alongside broad stability, while seasonal components exhibit three types of temporal shifts in fluctuations. A mismatch exists between the prevalence of environmental influences and their causal strength. Daytime land surface temperature (LST_D), surface runoff (RO), and evapotranspiration (ET) show the highest detection frequencies, yet volumetric soil water in layers 2 (SWVL₂) and RO exhibit the largest ranges in strength and drive variations at specific sites. Response times are asymmetric. Negative effects from ET on GWL transmit quickly, while positive recovery is slow. Conversely, positive recharge from volumetric soil water in layer 1 (SWVL₁) is faster than its negative lag. At the basin scale, surface processes recharge GWL while mediating indirect influences from other variables. Climate and agricultural irrigation act as direct sinks. Depending on local conditions, three regional patterns emerge: direct climate-driven depletion, obstructed shallow water retention, and indirect compensation from agricultural water use. Causal networks indicate that RO and SWVL₁ have the highest centrality and dominate water output, whereas SWVL₂ acts as a passive receiver. Pathways from the surface to GWL are also asymmetric. The most frequent path involves step-by-step infiltration along RO → ET → SWVL₁ → SWVL₂ → GWL. In contrast, the paths with the highest cumulative strength are shorter and faster, specifically RO → ET → GWL and RO → SWVL₁ → GWL. The identified pathways and lag parameters provide a direct basis for groundwater dynamic modeling and water resource management in the basin. Full article

Ulcerative colitis (UC) is a type of inflammatory bowel disease without curative therapeutics. Recent studies demonstrate that Akkermansia muciniphila exerts mitigating effects on UC, but the underlying mechanisms remain unclear. In this study, we isolated a strain of A. muciniphila, designated NND9, from the feces of DSS-induced ulcerative colitis model mice and investigated its effects on UC of the mouse model. NND9 significantly alleviated UC severity in the mice by restoring gut barrier integrity through improving colonic mucus layer thickness, mitigating goblet cell depletion, and halting epithelial cell death. Mechanistically, NND9 suppressed the expression of the Tnfrsf10b gene encoding death receptor 5 (DR5) on the surface of colonic epithelial cells. Additionally, NND9 inhibited the phosphorylation of kinase 3 (RIPK3) and the pseudokinase mixed-lineage kinase domain-like protein (MLKL) associated with the necrotic apoptosis pathway, thereby reducing gut epithelial cell death. NND9 also markedly ameliorated the gut microbiome of the colitis mice. Untargeted metabolomics analysis demonstrated that NND9 modulated both tryptophan and bile acid metabolism. In conclusion, NND9 exhibits curative effects on UC by resolving inflammatory reactions of the gut mucosa through the DR5-RIPK3/p-RIPK3-MLKL/p-MLKL pathway and redressing gut dysbiosis. This study provides valuable information for the development of innovative therapeutic strategies for the treatment of UC. Full article