Search Results (12,799)

The reactive transport of hexavalent chromium (Cr(VI)) in anthropogenically disturbed sites (e.g., mine waste rock dumps, chromium salt industrial sites) is critically influenced by physico-chemical heterogeneity, yet the interplay between physical and chemical heterogeneities remains poorly understood. This study employed a series of experiments and numerical modeling to investigate the transport of Cr(VI), focusing on the implications of physical heterogeneity—represented by preferential flow paths—and chemical heterogeneity—characterized by reductive mineral lenses. Key findings indicate that physical heterogeneity accelerates Cr(VI) breakthrough by 1.4 to 2.1 pore volumes (PV) relative to homogeneous columns. The presence of pyrite lenses delays breakthrough by 0.6–1.2 PV under neutral pH and 1.6–2.0 PV under acidic pH. At a flow rate of 3.0 m/day, the apparent sorption capacity decreases by ~62.5% compared to 0.3 m/day, indicating that physical advection largely suppresses chemical retention under high-flux conditions. The above results demonstrate that physical heterogeneity governs flow paths and advection rates, whereas chemical heterogeneity impedes transport through heterogeneous adsorption and reduction in Cr(VI) to Cr(III) along these pathways. Furthermore, the presence of preferential paths leads to greater spatial variability, which subsequently influences the interaction dynamics between Cr(VI) and reactive minerals in the aqueous environment. The dominance shifts between physical/chemical controls based on flow rates and pH. At higher flow rates, the influence of physical heterogeneity becomes more pronounced, diminishing chemical reactions due to insufficient residence time of Cr(VI). Conversely, a lower pH environment enhances pyrite dissolution, which decouples the dependency on physical heterogeneity by promoting homogeneous reactions. Further evidence was obtained through X-ray photoelectron spectroscopy (XPS) analysis. The experimental observations are complemented by TOUGHREACT-based reactive transport simulations, which further reveal that the apparent dominance shifts arise from competing timescales between advection and surface reaction. The insights gained from the study emphasize the necessity of integrating both physical and chemical spatial variability in risk assessments, transport modeling, and designing targeted remediation strategies. Full article

Background/Objectives: Alzheimer’s disease (AD), one of the most prevalent neurodegenerative disorders in the elderly, is characterized by progressive cognitive loss, amyloid-β (Aβ) plaque deposition, and neurofibrillary tangle formation. Cerebral hypoxia has been reported as a complex modulator of AD pathology, with hypoxia-inducible factor-1 (HIF-1) emerging as a central molecular marker associated with neurodegeneration. This review aims to comprehensively report the roles of HIF-1 signaling in AD pathogenesis, emphasizing its neuroprotective and neurotoxic mechanisms along with demonstrating the therapeutic potential and challenges of translating this pathway for AD therapeutics. Methods: A comprehensive literature search was conducted across PubMed, Scopus, Web of Science, Embase, and Google Scholar databases for articles published between January 2000 and December 2025 on the context. Results: Under mild hypoxic conditions, HIF-1 activation enhances neuronal survival through upregulation of glucose transporters, glycolytic enzymes, angiogenic factors, erythropoietin, and antioxidant defense mechanisms. In contrast, chronic hypoxia modulates HIF-1 into a pathogenic marker through transcriptional activation of β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) and γ-secretase, facilitating amyloidogenic APP processing, along with tau hyperphosphorylation. Moreover, HIF-1 exacerbates neuroinflammation through microglial activation and pro-inflammatory cytokine release. The cell-type-specific expression patterns of HIF-1α and the temporal dynamics of its activation regulate whether the pathway exerts neuroprotective or neurodegenerative effects. Conclusions: This review discusses the current understanding of HIF-1-mediated mechanistic insights in AD pathology and impacts of existing HIF-1 modulators on AD pathology, along with the therapeutic implications of targeting this pathway for translational application in AD therapeutics. Full article

In 2023, Murcia implemented a new sustainable urban Mobility Plan emphasizing pedestrianization, segregated public transportation, and the reduction of private vehicle traffic within the city. Consequently, this study aimed to evaluate heavy metal pollution in urban dust by comparing data collected prior to the plan’s implementation (2016) with that obtained afterward (2025). Systematic sampling of urban dust was conducted at 84 sites during both study periods. The concentrations of elements were quantified employing inductively coupled plasma mass spectrometry. The K-means algorithm was employed to identify data clusters. The analysis revealed a distinct geochemical shift, with the dominant elemental abundance changing from Fe > Zn > Mn > Pb > Cu > Cr in 2016 to Fe > Zn > Mn > Cu > Cr > Pb by 2025. Concentrations of Pb and Mn declined following the implementation of the Mobility Plan, whereas levels of As exhibited an increase between 2016 and 2025. Children are at risk of exposure arising from As, which was identified as the contaminant of greatest concern. The Murcia Mobility Plan, implemented in 2023, had a significant and multifaceted impact. It led to a decrease in traditional metal contaminants and simultaneously highlighted the emergence of new contaminants, such as arsenic (As). Full article

Shale gas reservoirs are characterized by low permeability, nanoscale pore structures, and complex fracture networks. Multistage fractured horizontal wells are an important technology for commercial shale gas development. However, many shale gas productivity models primarily emphasize gas transport within the reservoir and fracture system, while pressure variations caused by frictional losses along the horizontal wellbore are often simplified or treated separately. To address this issue, this study develops a fully coupled multiscale dual-porosity numerical model that integrates the shale matrix, hydraulic fractures, and horizontal wellbore within a unified simulation framework. The model incorporates key physical mechanisms governing shale gas transport, including Knudsen diffusion, Langmuir adsorption–desorption, stress sensitivity, and non-Darcy flow in fractures. Meanwhile, the Darcy–Weisbach equation is introduced to describe wellbore frictional pressure losses. The reliability of the proposed model is validated through history matching with field production data from the Changning shale gas reservoir. The results demonstrate that neglecting wellbore friction losses leads to a 30–50% overestimation of horizontal well productivity, indicating that wellbore friction has a significant impact on fracture flow distribution and productivity prediction. Furthermore, an exponent factor r is introduced to characterize and evaluate non-uniform fracture placement patterns. The results show that toe-dense fracture placement can increase cumulative gas production by approximately 37.8% compared with uniform fracture placement when r = 1.10, which yields the highest cumulative gas production among the tested cases. However, the additional production benefit becomes substantially smaller after the initial increase and remains relatively stable as r further increases. This study improves the understanding of friction-induced heel-to-toe effects and provides an effective numerical approach for productivity prediction and fracture placement design in shale gas horizontal wells. Full article

Woody biomass is often promoted as a low-carbon energy source in global decarbonization efforts. However, LCA (life cycle assessment) evaluations of woody biomass-to-energy systems show very different environmental performance. Variations in technology and methodology across investigations can cause these inconsistencies. This review paper analyzes methodologies of LCAs of woody biomass conversion routes such as combustion, combined heat and power, gasification, pyrolysis, torrefaction-assisted systems, and new bioenergy with carbon capture configurations. A systematic literature review was conducted using Scopus, SpringerLink, and ScienceDirect, identifying 4272 records, of which 98 studies were retained for detailed analysis following the application of defined inclusion and exclusion criteria. Functional unit selection, from biomass mass per unit to power or heat per unit, is highly variable, affecting comparability. Forest carbon stock fluctuations, infrastructure, and end-of-life treatment are inconsistently included in cradle-to-grave system boundaries. Static GWP100 methods are often used in biogenic carbon removal without considering temporal carbon dynamics. The importance of pretreatment steps like drying, pelletizing, and torrefaction cannot be overstated, even though they have a direct impact on the quality of the fuel, the efficiency of transportation, and the effectiveness of the conversion process downstream. The large range of stated emission levels for comparable technologies is further influenced by logistics assumptions, plant scale, and allocation mechanisms in cogeneration systems. The review synthesizes these methodological differences and proposes a harmonization methodology to increase woody biomass LCA transparency and comparability. By identifying important sources of outcome variability, this study helps policymakers, project developers, and industry stakeholders evaluate biomass energy investments and bring clarity to environmental decisions. Full article

The rapid expansion of fiber-reinforced polymers (FRPs) in wind energy, transportation, and aerospace is generating increasing amounts of accompanied waste, making effective valorization essential to a circular economy. This review compares FRP recovery technologies in terms of recovered-fiber quality, operating conditions, post-treatment, environmental impacts, and industrial applicability. Then, it also examines direct reuse, FRP remanufacturing, and reuse in cementitious composites. Quantitative synthesis indicates that high-quality recycled carbon fibers (rCFs) generally retain more than 90% of their original strength, whereas mechanically recovered glass fibers (rGFs) typically retain approximately 70–90%. The preferred pathway depends on the intrinsic value, damage state, morphology, and residual properties. Components with sufficient residual capacity should be directly reused; high-quality fibers are better suited to polymer remanufacturing; and heterogeneous or lower-grade glass-FRP (GFRP) fractions are more compatible with cementitious applications, where mechanically recycled GFRP can provide interfacial bond strengths comparable to conventional engineering macrofibers. Future research should establish quantitative links among recovered material quality, processing, interfacial behavior, and end-use performance, while adopting consistent environmental and economic assessment boundaries. A graded utilization framework is therefore required to support both large-scale and value-added reuse of FRP waste. Full article

The Amazon region harbors one of the richest biodiversities on the planet, representing a vast reservoir of bioactive compounds with high therapeutic potential. Although several Amazonian bioactives have already been incorporated into biopolymeric matrices, the effects of their incorporation on the mechanical, barrier, and biological properties of these materials remain insufficiently systematized. This review addresses this knowledge gap by critically analyzing reported Amazonian bioactive–biopolymer systems, with emphasis on how bioactive incorporation influences matrix properties, release behavior, and biological performance, particularly in biomedical applications. Emphasis is placed on the role of polymer–bioactive interactions in modulating physicochemical, mechanical, and transport properties, as well as in controlling release kinetics and biological performance. Different incorporation strategies, such as encapsulation and matrix embedding, are critically discussed in terms of their impact on stability and functionality. Overall, the reported studies demonstrate that Amazonian bioactives can substantially modulate the physicochemical, mechanical, barrier, and biological performance of biopolymeric systems, depending on the bioactive, polymeric matrix, and incorporation strategy. However, challenges related to variability in raw materials, lack of standardization, and limited reproducibility remain key barriers to translation and large-scale application. Full article

Background and Clinical significance: Potassium is one of the most frequently measured laboratory parameters used to assess a patient’s clinical status and is also one of the analytes most commonly affected by preanalytical errors. Case Presentation: A potassium test was ordered for a 63-year-old male patient. The result obtained was 6.4 mmol/L, indicating hyperkalemia, and a medical consultation was recommended in the laboratory report. As the potassium result was inconsistent with the patient’s clinical status, a new blood sample was analyzed the next day. This yielded a result that was 1.3 mmol/L (20%) lower. A detailed interview with the patient and the staff responsible for blood sample collection revealed that the spurious hyperkalemia was most likely caused by prolonged storage of the blood sample in a refrigerator implemented because of high ambient temperatures. Further analysis demonstrated that after storage of blood samples at low temperature, potassium concentration increased significantly on average by 5% and 20% at the 4 h and 8 h time points, respectively. Conclusions: Low temperature and prolonged blood sample storage before analysis significantly affect potassium results. Since even a slight alteration in potassium levels can have a severe impact on a patient’s health and may require immediate action, obtaining accurate potassium results requires ensuring appropriate conditions for sample storage and transport, and proper sample handling. This is particularly important in laboratories serving large geographical areas, where prolonged storage and transportation of blood samples can considerably extend the preanalytical phase. Full article

This exploratory descriptive-correlational study analyses the perceptions of 257 adult students (doctoral, master’s, and teachers) at DPPD, USV Iași, during the 2025–2026 academic year regarding hybrid education, teaching quality, and environmental sustainability. Using a structured Likert-scale questionnaire, the analysis indicates good-to-excellent internal consistency, with Cronbach’s alpha values ranging between 0.886 and 0.901, and a high overall global average score of 4.64. The findings reveal strong support for the hybrid model. Perceived teaching quality received the highest subscale rating (M = 4.80), closely followed by the perceived ecological impact (M = 4.65). The analysis indicates strong Pearson correlations, specifically between the hybrid learning experience and perceived teaching quality (r = 0.818), as well as between the perceived ecological impact and pro-sustainability attitudes (r = 0.809). Regarding academic mobility, the estimate indicates 81,283 km of avoided commuting travel and approximately 12,295 kg of avoided commuting-related CO₂ emissions, based on self-reported distance, means of transport, and number of physical attendances replaced by online activities. These findings suggest that hybrid learning may represent a relevant managerial option for university sustainability policies. The model appears well suited to postgraduate programmes addressed to employed adults, although the ecological benefits should be read as partial and do not displace perceived teaching quality as the central factor. Full article

This paper presents a comparative analysis of two models for direct current (DC) networks used in transmission expansion planning (TEP) problems. These models incorporate distinct sets of constraints and have different levels of detail: the transportation model incorporates only Kirchhoff’s First Law, while disjunctive model represents both Kirchhoff’s Laws. The choice of an appropriate modeling approach is a critical decision for planners, as it directly impacts the accuracy and feasibility of expansion plans. This study examines the impact of these different DC system representations, particularly in multi-terminal configurations with closed meshed topologies, on power flow calculations and system expansion investments. Although these models are well established for alternating current (AC) networks, their application to the DC portion of power systems is still under development regarding more complex grids. The results, obtained through modified IEEE test cases incorporating DC meshes along with a simplified example case, show superior results of the disjunctive DC formulation in comparison to the transportation model. Full article

Corrosion of reinforcing steel remains a major cause of premature deterioration in concrete infrastructure, motivating the development of inhibitors with lower toxicity and reduced environmental impact. This review critically examines recent advances in green and bio-based corrosion inhibitors for reinforced concrete, including plant extracts, agro-industrial residues, naturally occurring organic compounds, proteins, polysaccharides, bio-based coatings, hybrid formulations, and microbial systems. The available evidence is synthesized in terms of chemical functionality, delivery route, adsorption and film-forming mechanisms, electrochemical response, compatibility with cementitious materials, and durability under chloride- and carbonation-related exposure. Many formulations provide substantial inhibition under optimized laboratory conditions through interfacial adsorption, coordination with iron species, passive-film stabilization, suppression of anodic and cathodic reactions, and restriction of aggressive-species transport. However, reported efficiencies are not directly comparable because experimental scale, exposure conditions, dosage, steel preparation, and calculation methods vary considerably. Moreover, long-term reinforced-concrete and field studies remain scarce, while extract standardization, cement compatibility, toxicity, biodegradability, and life-cycle performance are frequently insufficiently addressed. Green and bio-based inhibitors therefore represent a promising but heterogeneous technology class. Their practical implementation requires chemically reproducible formulations, complementary electrochemical and surface evidence, concrete-scale durability assessment, environmental validation, and stage-gated progression toward monitored field applications. Full article

As the market of perishable goods in China continues to expand, reducing quality loss during transportation has become an urgent issue for the industry. Multimodal transport, as a key approach to optimizing the transportation structure and lowering logistics costs, has been increasingly adopted in practice. However, multimodal transport involves multiple transfers, and continuous vibration from transportation equipment throughout the transport process, together with impacts during transfer operations, can easily increase the loss of perishable goods, making it highly significant in practice to consider vibration loss during transportation in route planning. Since different transportation equipment generates different levels of vibration acceleration, this study considers the vibration losses caused by road, rail, and air transport. A bi-objective route optimization model for fresh produce multimodal transport is established, aiming to minimize total cost while maximizing product quality satisfaction. A hybrid algorithm combining an improved Strength Pareto Evolutionary Algorithm and a multi-objective adaptive large neighborhood search algorithm is designed to solve the model. The effectiveness of the model and algorithm is verified through case analysis, followed by sensitivity analysis on different time-sensitive factors of vibration damage and vibration acceleration. The results show that, compared with the multi-objective adaptive large neighborhood search algorithm and the non-dominated sorting genetic algorithm, the proposed algorithm can obtain solutions with lower total costs or higher product quality satisfaction. The minimum total cost of the multimodal transport scheme obtained by the proposed algorithm is reduced by 0.27% and 2.4%, respectively, compared with the multi-objective adaptive large neighborhood search algorithm and the non-dominated sorting genetic algorithm, while the maximum satisfaction is increased by 2.1% and 0.35%, respectively. Full article

Amid the well-researched negative effects of road congestion and increased private car use, there is a need for more sustainable modes of transport. The literature points towards trains as being a vital part of the solution to the current problems, but their success depends on a number of variables, especially when it comes to the main railway stations in the largest cities. The first goal of this study was to identify the relationship between passenger numbers at major railway stations in Poland and selected parameters characterizing public transport services; the second was to assess the usefulness of the NOAH (Nest of Apes Heuristic) method for data analysis. In Poland, the number of major transfer hubs is limited, and there is a lack of an existing method allowing comparison of variables in such small datasets in a way that infers statistical significance. This is a research gap that the authors aimed to address using the NOAH algorithm combined with an analysis of regression. The initial dataset had been successfully expanded in a way that dependencies could be observed, with both goals being met. Passenger numbers relied most on the number of trains departing at each station daily, while walking distance during transfers impacted that number most negatively. The results point towards other variables influencing the passenger numbers, which were not considered in this study but could form the basis of further research. The utilized method could also be applied to a different group of cities, and in other countries. Additionally, the study added to the development of the NOAH algorithm itself, improving the method. Full article

Donkeys and horses diverged approximately 4 million years ago and exhibit substantial genetic, chromosomal, and physiologic differences. Although mostly studied in horses, metabolic syndrome represents a broader metabolic dysfunction with systemic consequences, such as obesity and laminitis, that can impact the quality of life of equids. This review summarizes the current knowledge of glucose and insulin regulation in healthy horses and donkeys and examines the pathophysiology of equine metabolic syndrome (EMS) in comparison with donkey metabolic syndrome (DMS), including insulin dysregulation, impaired glucose transport, adipose tissue dysfunction, and emerging evidence of systemic meta-inflammation and oxidative stress. Compared with horses, donkeys demonstrate distinct patterns of adipose deposition, different metabolic profiles, and altered glucose and insulin dynamics following oral soluble carbohydrate intake. While our understanding of donkey medicine has expanded in recent years, gaps in knowledge remain regarding mechanistic insights into glucose metabolism and dysregulation in donkeys. Finally, we evaluate current and emerging therapeutic strategies, including dietary management, exercise, nutraceuticals, and pharmacologic interventions such as metformin and sodium–glucose cotransporter 2 inhibitors (SGLT2is). While these therapeutic approaches have demonstrated efficacy in horses, evidence in donkeys remains extremely limited. This highlights a critical need for species-specific research to elucidate the pathophysiological mechanisms and optimize therapeutic strategies for donkeys. Full article

With urban rail transit networks gradually entering a mature stage of development, whether newly added lines and stations can still improve local labour market outcomes remains an important question in transport planning and urban regeneration research. This paper examines light rail transit expansion in three mature UK cities: Manchester, Sheffield, and Nottingham. Using MSOA-level panel data from 2013 to 2024, this study applies a Difference-in-Differences (DID) approach to evaluate the impact of light rail transit expansion on local labour market vulnerability. MSOAs intersecting with the 500-m buffer zones of newly opened light rail stations are defined as the treatment group, while MSOAs not directly affected by light rail expansion are used as the control group. The Claimant Count is used as a proxy for welfare dependency and labour-market vulnerability. The results show that light rail transit expansion significantly reduces the Claimant Count in treated areas, with an estimated decline of approximately 7.52–7.56%. This finding remains robust after adding demographic, socio-economic, and built environment controls, applying MSOA-level clustered standard errors, implementing PSM-DID, and conducting placebo tests. Mechanism analysis further shows that light rail expansion is associated with changes in the functional structure of station areas, including increases in overall POI density and service-oriented facilities, while manufacturing and production-related facilities decline. These findings suggest that light rail expansion may reduce local unemployment-related welfare dependency by improving employment accessibility, alleviating spatial mismatch, and promoting service-sector agglomeration. This study provides new empirical evidence on the socio-economic effects of light rail expansion in mature UK cities. Full article