Search Results (1,963)

Hepatorenal syndrome (HRS) is a high-mortality, potentially reversible form of kidney failure that arises from a tight hemodynamic–inflammatory coupling in cirrhosis. Contemporary redefinitions prioritize creatinine kinetics over static thresholds and recognize non-acute kidney injury (AKI) functional phenotypes, enabling earlier recognition but heightening the need for precise etiologic triage. This narrative synthesis integrates current concepts across pathophysiology, diagnosis and management. Portal hypertension, bacterial translocation and inflammatory mediators amplify splanchnic vasodilation and effective arterial underfilling. Compensatory neurohumoral activation precipitates renal vasoconstriction, intrarenal microcirculatory dysfunction and sodium–water retention. The pivotal diagnostic fork remains HRS–AKI versus acute tubular necrosis. A pragmatic, tiered strategy, structured volume assessment, filtration markers and a parsimonious tubular-injury panel offer actionable discrimination, whereas fractional excretion indices serve as adjuncts only. Initial therapy should be bundled and time-sensitive: remove nephrotoxins, treat infection and initiate albumin plus a vasoconstrictor. The transplant strategy should default to isolated liver transplantation unless end-stage renal disease is established. Future priorities include validated biomarker cut-offs, ultrasound-guided volume algorithms and pathway-based trials to reduce diagnostic delay and improve survival. Full article

This paper advances a novel bio-cognitive framework for understanding how urban peripheries function as disabling environments that systematically undermine human flourishing. Drawing on recent theoretical developments in predictive processing, 4E cognition (embodied, embedded, enactive, and extended), and biology, we propose that marginalization in urban contexts emerges not merely from socio-economic deprivation but from fundamental disruptions to cognitive, physiological, and embodied processes. Our analysis illustrates how peripheral spaces operate as neuro-affective ecologies that constrain agency through the breakdown of sensorimotor coupling, the generation of persistent prediction errors, and the activation of chronic stress responses. We argue that environmental features characteristic of urban peripheries, such as fragmented infrastructure, limited affordances, and unpredictable spatial configurations, create conditions where the dynamic interplay between body, brain, and environment systematically impairs inhabitants’ capacity for effective action and adaptation. This bio-cognitive perspective challenges conventional approaches that frame peripheries primarily through geographic or policy lenses, instead revealing how spatial injustice also operates at the intersection of neural, bodily, and environmental processes. Our framework contributes to emerging debates on spatial justice by providing a scientifically grounded account of how built environments become constitutively disabling, offering new conceptual tools for policy interventions that address the embodied and cognitive dimensions of urban inequality. The implications extend beyond urban planning to fundamental questions about how environments shape human potential and the ethical imperatives of creating spaces that support rather than constrain human flourishing. Full article

Near-fault ground motions significantly threaten bridges due to their distinct features, which are often inadequately considered in current seismic codes based mainly on far-field records. This study analyzes 941 near-fault records to evaluate the effects of site class, pulse-like motions, and vertical components on the peak acceleration ratio and normalized response spectra. A finite element model of a typical simply supported girder bridge is developed to examine how these factors affect pier internal forces. Results show that the peak acceleration ratio increases with softer sites and exhibits large scatter in near-fault regions, indicating that the conventional vertical-to-horizontal ratio of 0.65 may significantly underestimate vertical seismic actions. Pulse motions shift and broaden response spectra, raising seismic demands for medium- to long-period structures. Additionally, pulse effects combined with soft sites cause coupled amplification of internal forces. This work offers a theoretical basis for seismic design and assessment of similar bridges. Full article

Calmodulin (CaM) plays a central role in cardiac excitation–contraction coupling by regulating ion channels, including the L-type calcium (Ca²⁺) channel Ca_v1.2 and the voltage-gated potassium (K⁺) channel K_v7.1. Mutations in CaM are linked to severe arrhythmogenic disorders such as Long QT syndrome (LQTS), yet the molecular mechanisms remain incompletely understood. Here, we investigate the structural and functional consequences of the arrhythmia-associated CaM variant D133H. Biophysical analysis revealed that D133H destabilises Ca²⁺ binding at the C-terminal lobe of CaM, altering its Ca²⁺-dependent conformational changes. Electrophysiological recordings demonstrated that CaM D133H impairs Ca²⁺-dependent inactivation (CDI) of Ca_v1.2, prolonging Ca²⁺ influx, while also reducing activation of K_v7.1, thereby limiting repolarising K⁺ currents. Together, these dual defects converge to prolong action potential duration, providing a mechanistic basis for arrhythmogenesis in LQTS. Our findings establish that CaM D133H perturbs both Ca²⁺ and K⁺ channel regulation, highlighting a shared pathway by which calmodulinopathy mutations disrupt cardiac excitability. Full article

Adult neurogenesis is well established in canonical niches—the dentate gyrus and the subventricular zone, where aerobic exercise reliably enhances progenitor proliferation, survival, and synaptic integration via increased cerebral blood flow, neurotrophins (e.g., BDNF, IGF-1), neurotransmitter regulation, and reduced neuroinflammation. Nutraceuticals (e.g., polyphenols, omega-3, creatine, vitamins) further support neuroplasticity and neuronal survival through convergent trophic, anti-inflammatory, and metabolic pathways. By contrast, the hypothalamus, a metabolically pivotal, non-canonical niche, remains comparatively understudied. Here, we synthesize anatomical and functional features of hypothalamic neural stem cells, primarily tanycytes (α1, α2, β1, β2), which line the third ventricle and differentially contribute to neuronal activity regulation, metabolic signaling, and cerebrospinal fluid–portal vasculature coupling, thereby linking neurogenesis to endocrine control. Notably, tanycytes can form neurospheres in vitro, enabling mechanistic interrogation. Although evidence for adult hypothalamic neurogenesis in humans is debated due to methodological constraints, animal data suggest potential relevance to disorders characterized by neuronal loss, metabolic dysregulation, and impaired neuroendocrine function. We propose that an integrative framework is timely: exercise and diet likely interact in the hypothalamic niche through shared mediators (BDNF, IGF-1, CNTF, GPR40) and exercise-derived signals (e.g., lactate, IL-6) that may be complemented by defined nutraceuticals. Yet critical uncertainties persist, including the extent of bona fide hypothalamic neurogenesis, nucleus-specific responses (arcuate nucleus, paraventricular nucleus, ventromedial hypothalamic nucleus), and the mechanistic integration of lifestyle signals in this region. To address these gaps, we outline actionable priorities: (i) single-cell and lineage-tracing studies of tanycyte subtypes under distinct training modalities (aerobic, high-intensity interval training, resistance); (ii) combinatorial interventions pairing structured exercise with nutraceuticals to test synergy on progenitor dynamics and inflammation; and (iii) multi-omics and translational studies to identify biomarkers and establish clinical relevance. Clarifying these interactions will determine whether lifestyle and supplementation strategies can synergistically modulate hypothalamic neurogenesis and inform therapies for neurological, neuropsychiatric, and metabolic disorders. Full article

Manhole shafts in urban drainage systems are prone to accumulating trapped air pockets during intense rainfall, which can lead to sudden bounce of hinged covers and pose significant near-field risks. However, threshold criteria at the prototype scale remain unavailable. To obtain quantitative evidence of cover bounce under full-scale conditions and to clarify the effects of counterweight, dual-shaft coupling, and pressure–displacement phase lag, a series of experiments have been conducted on a prototype platform consisting of two shafts with hinged covers. Tests have been repeated under various counterweight conditions ranging from 0 to 30 kg. Pressure data from multiple transducers and high-speed video recordings have been synchronously acquired, filtered, and temporally aligned. Based on these, the critical overpressure at initial lift-off was identified, and oscillation characteristics and coupling effects have been analyzed. The critical overpressure was found to increase monotonically with added counterweight. When the counterweight was large, the system transitioned into a decaying response, with negligible subsequent bounce. The single-peak “rise–fall” pattern observed in single-shaft conditions no longer appeared when both covers lifted simultaneously. Notably, the critical overpressure did not coincide with the pressure peak, and a significant phase lag was observed between the pressure maximum and the moment of maximum displacement. These findings provide actionable support for the identification, modeling, and rapid mitigation of manhole cover bounce risks in urban drainage systems. Full article

Silicone rubber, primarily composed of polydimethylsiloxane (PDMS) chains, is widely used in sealing materials due to its excellent flexibility and durability. Its performance is significantly affected by environmental conditions, with humid-heat aging being a major factor of degradation. In this study, molecular dynamics simulations were conducted to systematically investigate the effects of water and temperature on PDMS at the molecular scale. The glass transition temperature (T_g) and free volume distribution were analyzed to evaluate the mobility of polymer chains under hydrated conditions. Mechanical simulations (including tensile and compressive deformation) indicate that the combined effect of elevated temperature and moisture significantly accelerates the degradation of rubber properties. Thermal decomposition simulations indicate that, under high-temperature and humid conditions, PDMS main chains gradually break into small molecules, with free radical reactions further promoting the aging process. The results elucidate the molecular mechanisms underlying silicone rubber performance deterioration under the coupled action of water and temperature, providing a theoretical basis for service-life prediction and durability design of sealing materials. Full article

With the growing global demand for mineral resources, enhancing the transport capacity of heavy-haul railways (HHR) has emerged as a key area of research. As an emerging train formation technology, the virtual coupling train system (VCTS) has the potential to substantially increase the traffic density of heavy-haul trains (HHT) and thereby improve transport efficiency. However, the stable operation of virtually coupled fleets relies on train-to-train (T2T) communication, which is vulnerable to jamming attacks (JAs) within the complex operational environments of HHR. To address issues such as train decoupling and emergency braking in the VCTS that may be caused by JAs, this study proposes a stochastic game-based anti-jamming control (SGAC) strategy aimed at ensuring the stability and operational safety of the VCTS operating within HHR. The proposed approach models both JAs and defensive actions as a stochastic game and employs an $H^{\infty }$-based cross-layer control method to mitigate their adverse effects. The control performance is analyzed through frequency-domain mapping, and a quantitative evaluation is conducted using the $H^{\infty }$ norm. The simulation results demonstrate that the SGAC scheme significantly enhances the resilience of VCTS cooperative control under JAs, offering a robust solution for ensuring the stable operation of HHR. Full article

Background: Healthcare systems worldwide face growing challenges in anticipating and managing patient surges, particularly in times of public health crises, natural disasters, or seasonal peaks. The ability of healthcare organisations to forecast and respond to such demand fluctuations—referred to as organisational readiness for patient capacity surge—has become a critical determinant of service continuity and patient outcomes. Despite the urgency, there remains a lack of consolidated evidence on how healthcare authorities measure, evaluate, and operationalise this readiness. This systematic review aims to identify and synthesise existing literature that presents case studies, methodologies, and strategic frameworks used to evaluate organisational preparedness for patient surge capacity. It also explores resource allocation mechanisms, hospital capacity planning algorithms, and temporary facility strategies documented in healthcare settings. Methods: The review was conducted across two major scientific repositories, i.e., PubMed and Web of Science (WoS). A set of four structured search queries were formulated to capture the breadth of the topic, focusing on demand forecasting, hospital capacity planning, workforce models, and resource management within the context of healthcare surge demand. The search was limited to publications from the last 10 years (2014–2024) to ensure the inclusion of contemporary practices and technologies. Results: A total of 142 articles were selected for detailed analysis. The articles were categorised into six thematic groups: (i) empirical case studies on healthcare surge management; (ii) hospital resources and capacity scaling; (iii) ethical frameworks guiding surge response; (iv) IT-driven algorithms and forecasting tools; (v) policy evaluations and actionable lessons learned; and (vi) existing systematic reviews in related domains. Notably, several articles provided evidence-based frameworks and simulation models supporting predictive planning, while others highlighted real-world implementation of temporary care facilities and staff redeployment protocols. Conclusions: The review underscores the fragmented yet growing body of literature addressing the multidimensional nature of surge preparedness in healthcare. While algorithmic forecasting and capacity modelling are advancing, gaps remain in standardising metrics for organisational readiness and incorporating ethical considerations in surge planning. Limitations of this review include potential selection bias and the subjective categorisation of articles. Future research should aim to develop integrative frameworks that couple technical, operational, and ethical readiness for patient surge scenarios. Full article

Achieving carbon neutrality is a global priority, and China’s “dual-carbon” goals place urgent demands on emission reduction. In this context, the digital economy and industrial structure transformation are key drivers of synergistic carbon mitigation and sustainable development. This study constructs an integrated analytical framework, combining an improved three-system coupling coordination model, exploratory spatial data analysis, and panel vector autoregression, using panel data from 30 Chinese provinces between 2013 and 2022. The results reveal three main findings: (1) Spatial heterogeneity: The digital economy follows an “advanced East—catching-up Central—lagging West” pattern, while carbon emissions show a “higher North—lower South” gradient. (2) Improving coordination with regional disparities: Overall coupling coordination has steadily increased, but Eastern provinces exhibit stronger synergistic capabilities than Central and Western regions. (3) Bidirectional interactions and self-reinforcing effects: Digital economy development drives industrial structure upgrading, which in turn promotes long-term carbon reduction; all three systems display self-reinforcing dynamics. These findings provide robust empirical evidence on the complex co-evolution of digital economy, industrial transformation, and carbon emissions, offering actionable insights for policymakers to design region-specific strategies for coordinated low-carbon development. Full article

Extensive high and steep open-pit slopes in gneiss are distributed in cold regions at high altitudes or high latitudes of China, such as Qinghai, Tibet, and Xinjiang, posing significant hazards to mine safety. Several recent slope failure incidents highlight the urgent need to study the failure modes and mechanisms of gneiss open-pit slopes in these cold regions. This study focuses on the 14 September 2023 landslide at the Jinbao Mine in Xinjiang. Initially, field investigation and displacement monitoring were employed to analyze its failure characteristics and mode. Subsequently, utilizing mechanical parameters of the gneissic foliation and the rock mass obtained under various conditions, discrete element numerical modeling was conducted to study the failure mechanisms. The results indicate that the landslide was a typical bedding failure characterized by an upper bedding-controlled sliding zone, combined with buckling and crushing of the slope toe. Under the long-term combined effects of rainfall, freeze–thaw cycles and blasting, the shear strength of the gneissic foliation decreased. This reduction led to a decrease in the anti-sliding force and an increase in the sliding force within the upper bedding-controlled sliding zone. Consequently, the load transferred to the rock mass at the slope toe progressively increased. Under prolonged compression, the toe rock mass experienced bending, which intensified over time. Coupled with the strength reduction caused by the repeated action of rainfall, freeze–thaw cycles and blasting, the toe rock mass gradually fractured and ultimately failed in a buckling mode. This led to the loss of support for the upper mass, which then subsided along the foliation, precipitating the landslide’s overall instability. Full article

Environmental issues have become increasingly critical and frequent in recent decades due to excessive population growth and intensified industrial and mining activities. Among the most concerning contaminants is arsenic (As), a toxic element associated with severe environmental and human health risks. This study aimed to investigate the bioremediation potential of the bacterial strains Lysinibacillus boronitolerans and Bacillus cereus, elucidating the mechanisms involved in arsenic transformation and removal under controlled conditions. The strains were cultivated in liquid medium containing known concentrations of As(III) and As(V), and the chemical forms of arsenic were analyzed using High-Performance Liquid Chromatography coupled with Inductively Coupled Plasma Mass Spectrometry (LC-ICP-MS). The production of exopolysaccharides (EPSs) and arsenite oxidase activity were also evaluated. Morphological and elemental analyses were performed using scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). The bacterial strains exhibited significant 69.38–85.72% reductions in arsenic concentration and approximately 14–15% volatilization rates. No EPS production or arsenite oxidase activity was detected, suggesting alternative detoxification pathways. SEM-EDS analyses revealed intracellular accumulation of arsenic, while LC-ICP-MS speciation confirmed interconversion between As(III) and As(V), indicating the action of methylation-dependent detoxification and membrane transport mechanisms. The findings demonstrate that L. boronitolerans and B. cereus possess efficient arsenic resistance and transformation mechanisms, even without conventional enzymatic pathways. These strains show strong potential for use in sustainable bioremediation of arsenic-contaminated environments, particularly in regions affected by mining activities. Full article

Urban underground pipeline aging and leakage can result in soil erosion and ground collapse, constituting a major threat to urban public safety. To investigate this disaster mechanism, this present study established a two-dimensional numerical model based on the computational fluid dynamics–discrete element method (CFD–DEM) two-way fluid–solid coupling approach, simulating and reproducing the entire process from soil erosion, soil arch evolution to ground collapse caused by underground pipeline leakage in water-rich sand layers. The simulation shows that under the action of seepage pressures, soil particles are eroded and lost, forming a cavity above the pipeline defect. As soil continues to be lost, the disturbed zone expands toward the ground surface, causing ground settlement, and in water-rich sand layers, a funnel-shaped sinkhole is eventually formed. The ground collapse process is closely related to the groundwater level and the thickness of the overlying soil layer above the pipeline. Rising groundwater levels reduce the effective stress and shear strength of the soil, significantly exacerbating seepage erosion. Increasing the thickness of the overlying soil layer can enhance the confining pressure, improve soil compactness, and promote the formation of soil stress arch, thereby effectively slowing down the rate of ground collapse. This study reproduces the process of ground collapse numerically and reveals the mechanism of ground collapse induced by underground pipeline leakage in water-rich sand layers. Full article

Accurately constructing a soil–water characteristic curve (SWCC) model that accounts for the combined effects of multiple factors is of great significance for in-depth understanding of the physical and mechanical behaviors of soils in complex environments. Based on the van Genuchten (vG) model, this study systematically analyzed the effect of the coupling mechanism of void ratio, temperature, and salinity on SWCC. An SWCC model capable of characterizing multi-factor coupling effects was established by incorporating multi-factor influence terms. Fitting verification with experimental data demonstrates that the proposed model can effectively depict soil water retention characteristics under the combined action of multiple factors. Furthermore, parameter sensitivity analysis clarifies the influence laws of each model parameter on the air entry value and the slope of the transition segment of SWCC. To address the challenge of cumbersome determination of model parameters, a parameter prediction method based on the Bayesian regularized neural network (BRNN) was proposed. By training a large volume of SWCC experimental data under multi-factor conditions, effective prediction of model parameters was achieved, with the input being the basic physical properties of soil and environmental variables and the output being the target model parameters. Considering that the influence of salinity introduces additional parameters, the training set was divided into two scenarios (saline and non-saline conditions) for separate modeling to enhance the pertinence and accuracy of parameter prediction. Prediction results indicate that the proposed method exhibits reliable parameter prediction capability, and its prediction accuracy is mainly influenced by the quantity and quality of training data. Full article

Cementitious materials are multiscale and multiphase composites whose frost resistance at the macroscale is closely governed by microstructural characteristics. However, the interfacial transition zone (ITZ) between clinker and hydrates, recognized as the weakest solid phase, plays a decisive role in the initiation and propagation of microcracks under freezing conditions. Understanding the frost damage mechanism of ITZ is therefore essential for improving the durability of concrete in cold regions. The motivation of this study lies in revealing how freezing affects the mechanical integrity and microstructure of ITZ in its early ages, which remains insufficiently understood in existing research. To address this, a nanoscratch technique was employed for its ability to quantify local fracture properties and interfacial adhesion at the submicronscale, providing a direct and high-resolution assessment of ITZ behavior under freeze–thaw action. The ITZ thickness and fracture properties were characterized in unfrozen cement paste and in cement paste frozen at 1 and 7 days of age to elucidate the microscale frost damage mechanism. Moreover, the enhancement effect of nano-silica modification on frozen ITZ was investigated through the combined use of nanoscratch and mercury intrusion porosimetry (MIP). The correlations among clinker particle size, ITZ thickness, and ITZ fracture properties were further established using nanoscratch coupled with scanning electron microscopy (SEM). This study provides a novel micromechanical insight into the frost deterioration of ITZ and demonstrates the innovative application of nanoscratch technology in characterizing freeze-induced damage in cementitious materials, offering theoretical guidance for designing durable concrete for cold environments. Full article