Search Results (2,109)

Ball screw feed systems are critical components of CNC machine tools, and their health condition directly affects positioning accuracy and operational reliability. However, variations in rotational speed under changing operating conditions can cause substantial shifts in fault characteristics, limiting the generalization capability of conventional fault identification methods developed under a single operating condition. To address this issue, a feature-enhanced multi-kernel domain adaptation framework is proposed for cross-domain fault identification of ball screw feed systems. First, an attention-based feature enhancement module is developed to adaptively reweight vibration features, thereby emphasizing informative feature components and suppressing redundant and noise-related information. Subsequently, a residual feature extraction and fusion module is employed to learn hierarchical fault representations and improve feature discriminability. Finally, a multi-kernel maximum mean discrepancy (MK-MMD) strategy is integrated with adversarial domain adaptation to reduce feature distribution discrepancies between source and target domains under different rotational speeds and ball screw specimens. Local spalling fault experiments were conducted on the developed test bench, where vibration signals were collected using an accelerometer under various operating conditions and subsequently used to validate the proposed framework. Experimental results demonstrate that the proposed method achieves an average identification accuracy of 92.9% across the 12 investigated cross-domain tasks, compared with 69.7% for the optimized source-only CNN, with the performance gap becoming particularly pronounced under cross-specimen transfer conditions. The results indicate that the proposed framework improves the learning of fault-discriminative and domain-invariant representations, thereby improving the robustness of ball screw fault identification under variable operating conditions. Full article

Land-use changes are widely recognized as important drivers of terrestrial carbon sinks. However, how changes in land-use patterns affect the interannual variability of net ecosystem productivity (NEP) remains unclear. This study analyzed the impacts of land-use patterns on NEP in Hubei Province from 2001 to 2025, utilizing MODIS NPP data, the China Land Cover Dataset (CLCD), and meteorological observations. Linear and nonlinear trends of NEP were examined using the Mann–Kendall (M-K) trend test and Ensemble Empirical Mode Decomposition (EEMD), respectively. Four landscape metrics, the contagion index (CONTAG), largest patch index (LPI), patch density (PD), and Patch Richness (PR), were calculated to characterize land-use pattern changes, and Pearson correlation analysis was employed to explore their interannual relationships with NEP. The results showed that the linear increasing trend of NEP masked widespread nonlinear shifts: while the M-K trend test indicated significant increases in 40.6% of the area, EEMD revealed that only 11.91% exhibited true monotonic increases, whereas 44.8% presented an increasing-to-decreasing trend. These shifts were predominantly concentrated in the Jianghan Plain, Northeast Hubei, and eastern Northwest Hubei, where cropland-to-impervious conversion was relatively intense and landscape metrics exhibited relatively pronounced nonlinear changes. LPI and CONTAG were significantly negatively correlated with NEP in these areas, which was consistent with the fragmentation of contiguous landscapes by urban expansion. In contrast, PD showed contrasting correlation directions. It was positively correlated with NEP in the plain areas, but negatively correlated in the mountainous areas, suggesting divergent associations of landscape fragmentation under different landscape matrices. PR exhibited the weakest correlations with NEP overall. This study highlights that nonlinear trend analysis is essential for accurately assessing carbon sink dynamics and that landscape patterns exert spatially heterogeneous effects on NEP, providing a scientific basis for differentiated land-use management strategies for carbon sequestration in Hubei Province. Full article

Extreme weather events have increasingly disrupted Haiti’s socio-economic development. This study assesses long-term trends in mean and extreme temperature, precipitation, and near-surface humidity indices across Haiti for 1981–2020, using ERA5-Land temperature and humidity fields together with Multi-Source Weighted-Ensemble Precipitation (MSWEP), both at 0.1° resolution. Trends were quantified with the Theil–Sen estimator and tested with Mann–Kendall (MK) after Trend-Free Pre-Whitening (TFPW). Warm days (TX90p, percentage of days when daily maximum temperature exceeds the 90th percentile of the reference period) and warm nights (TN90p, percentage of days when daily minimum temperature exceeds the 90th percentile) increase nationwide by about 12 and 20 additional days per decade, while mean maximum and minimum temperatures warm by 0.17 °C and 0.22 °C per decade, respectively. Nocturnal warming is accompanied by a significant rise in near-surface water vapor pressure (+0.15 hPa per decade), whose detrended interannual variability correlates strongly with TN90p (r = 0.59), identifying the water-vapor greenhouse effect as a key driver of the faster warming of nights than days. Precipitation shows no significant national trend, except for very wet days (R90p, percentage of days with precipitation above the 90th percentile of wet days, +2.18% per decade) and a decline in rainy days (RR1, number of days with precipitation ≥ 1 mm, –4 days per decade). These results provide the first country-wide baseline of temperature and precipitation extremes for climate-risk assessment in Haiti. Full article

Forest ecosystem water conservation is an important ecohydrological regulating service for sustaining mountain watersheds under climate change. This study assessed water-conservation services in the eastern Dabie Mountains of China by integrating the InVEST Water Yield module under the Budyko framework, a Coupling Coordination Degree (CCD) model, and pixel-scale Theil–Sen, Mann–Kendall, and Ordinary Least Squares analyses. The study covered 1985–2024 through ten benchmark years (1985, 1990, 1995, 2000, 2005, 2010, 2015, 2020, 2022, and 2024). Mean water-conservation capacity across the benchmark-year maps was 362.7 mm. The OLS slope was 1.40 mm/a, while the two-sided MK test was non-significant (Z_MK = 0.54, p = 0.592), indicating a weak positive tendency in the benchmark-year sequence. Year-to-year variation was closely associated with hydroclimatic conditions, with canopy interception, litter storage, soil-water storage, and flow attenuation providing process pathways within the model framework. Water-conservation capacity reached 534.4 mm in the wet 2020 benchmark year, declined to 268.2 mm during the 2022 drought, and recovered to 369.6 mm in 2024. Comparison with area-scaled official bulletin surface-water references for seven overlapping years yielded a mean absolute percentage error of 5.21% and absolute relative errors of 0.00%–17.62%. High-value service areas were concentrated in the central forested massif, whereas low-value and coordination-imbalance areas were more common along agricultural and urbanizing margins. The integrated framework links service intensity, coordination status, and historical tendency to support differentiated watershed management and to identify spatial contrasts together with benchmark-year hydroclimatic responses. Full article

Background: Antimicrobial resistance (AMR) poses a significant threat to global health and economic development. In Malawi, the economic costs associated with the treatment of AMR infections remain largely unknown which may hinder resource allocation and policy prioritization. Method: The study used a cross-sectional design and was conducted between September 2023 and January 2025 at three different hospital settings. Data were collected from inpatients with laboratory-confirmed urinary tract infection (UTI) or blood stream infection (BSI). Additional follow-up data were collected from patients for four weeks post discharge. We analyzed patient level data first using descriptive statistics and employed an instrumental variable 2-stage least squares regression to estimate drivers of AMR treatments costs. Results: A total of 610 patients participated in the study. Of these, 45% had AMR-associated resistant infections. Overall, E. coli (43%) followed by P. aeruginosa (22%), K. pneumoniae (14%), and S. aureus (10%) were the most common pathogens. UTI was marginally more common (51%) compared to BSI (49%). BSI had a higher average cost than UTI for patients with both susceptible and resistant infections. On average, a patient spent MK283,815.10 (US$163.71) ranging from zero to MK13,500,000 (US$7786.90). Patients with resistant infections incurred, on average, MK161,785 (US$93.32) more than patients with susceptible infections, largely driven by prolonged hospitalization among other factors. Overall, the direct medical observed costs averaged MK37,165.29 (US$21.44) while direct non-medical observed costs averaged MK61,908.71 (US$35.71). Productivity losses for the patient and guardian(s) were a major observed cost averaging MK160,322.80 (US$92.49). The regression results further showed that having a bank account as a proxy of wealth, non-farm business, longer travel duration, BSI, and K. pneumoniae as the causative pathogens were significantly associated with increased cost burden among the patients. Conclusions: AMR-associated infections impose substantial economic burden on patients and households. Further strengthening of AMR surveillance and stewardship are needed as critical elements of Malawi’s National Action Plan. However, measures should also be taken to mitigate the economic consequences related to AMR, especially for patients who bear the brunt of these costs for lack of financial protection in Malawi’s health system. Full article

Background: Moderate-to-high refractive error generates long-term direct and indirect costs through corrective devices, complications, and productivity losses. The economic value of implantable collamer lens (ICL) surgery relative to contact lens (CL)-based correction with backup spectacles remains uncertain. Objective: To evaluate the 25-year cost-effectiveness of posterior chamber phakic ICL implantation versus CL-based correction across four refractive subgroups from a Norwegian societal perspective. Methods: A Markov cohort model followed patients aged 25–50 years with high myopia, high myopia with astigmatism, high hyperopia, or high hyperopia with astigmatism. Health states incorporated surgical complications, microbial keratitis (MK), cataract, explantation, and death. Direct medical and productivity costs were valued in 2024 Norwegian kroner (NOK), converted to United States dollars (USD), and subsequently reported in USD. Outcomes included quality-adjusted life-years (QALYs), incremental costs, incremental net monetary benefit (INMB), and cost-effectiveness probabilities at Norwegian severity-based thresholds (NOK 250,000–825,000/QALY). Deterministic and probabilistic sensitivity analyses were performed. Results: In the deterministic base case, ICL was less costly and more effective in all subgroups. Incremental QALY gains ranged from 0.049 to 0.464, and 25-year savings ranged from USD 1758 to USD 2277 per patient. At USD 27,253/QALY, INMB ranged from USD 3264 to USD 14,921. ICL produced approximately 5–6 additional cataract surgeries per 100 patients but avoided approximately 1.1–1.3 MK infections per 100 CL users and provided 0.6–0.9 additional years in the “Well” state. Cost-effectiveness probabilities ranged from 52.7% to 74.2% and were highest in the astigmatic subgroups. Utilities were the principal uncertainty drivers; the 52.7% probability observed for high hyperopia indicated limited robustness. Conclusions: Over 25 years, ICL may provide cost savings and quality-of-life gains compared with CL-based correction in appropriately selected patients. These findings depend on model assumptions and should not be interpreted as a lifetime evaluation. Full article

Extracellular vesicles (EVs) mediate endocrine and metabolic signalling. EV responses to shifts in substrate utilisation, from euketonaemia to hypoketonaemia, remain poorly understood. Chronic hyperinsulinaemia suppresses ketogenesis, causing hypoketonaemia; however, its impact on EV profiles in metabolically healthy individuals has not been characterised. We investigated the effects of hypoketonaemia on EV profiles in the KetoSAge cohort, examining associations between EV concentration, mean size, and modal size and metabolic–endocrine biomarkers. Ten lean (BMI, 20.52 ± 1.39 kg/m²), healthy premenopausal women (mean age, 32.30 ± 8.97 years) maintaining euketonaemia (mean 3.9 ± 2.3 years) completed a three-phase crossover trial, comprising 21 days each of: euketonaemia (baseline), induced-hypoketonaemia, and return-to-euketonaemia. No statistically significant phase-level differences in EV concentration or size parameters were detected. Linear mixed-effects analyses identified nominally significant associations between EV concentration and adiponectin, free T3, bilirubin, luteinising hormone, and epidermal growth factor, between EV mean size and HDL-cholesterol and between EV modal size and insulin, HOMA-IR, beta-hydroxybutyrate, GKI, thyroid hormones, ALT, AST, IL-6 and oestrogen (all unadjusted p < 0.05). However, none of these associations remained statistically significant after false discovery rate correction (FDR < 0.10). Hypoketonaemia via insulin-compensated euglycaemia revealed coordinated EV–biomarker relationships across metabolic–endocrine, hepatic and inflammatory pathways. Although exploratory, these findings suggest that EV profiles may reflect an insulin-responsive signalling network linked to the systemic bioenergetic state, highlighting their potential as early indicators of metabolic–endocrine adaptation. Full article

A series of novel quinazolinone-based aldazine and ketazine derivatives (4a–l and 6) was synthesized through the condensation of hydrazine intermediate 2 with substituted aldehydes and isatin using chitosan sulfonic acid (CS–SO₃H) as a recyclable heterogeneous catalyst. The reactions were performed under conventional reflux and solvent-free grinding conditions. The grinding method afforded the target compounds in higher yields (84–90%) within shorter reaction times (21–33 min) using 10 mol% CS–SO₃H at 25 °C. The synthesized compounds were characterized using spectroscopic and elemental analyses. Cytotoxic evaluation against HepG-2 liver carcinoma cells identified compound 4k as the most potent derivative, with an IC₅₀ value of 4.47 ± 0.25 µM. Compounds 4b, 4f, 4h, and 4k exhibited low cytotoxicity toward the non-tumor LLC-MK2 cell line, with IC₅₀ values above 100 µM and selectivity indices of >20.28, >16.00, >16.61, and >22.37, respectively. SAR analysis indicated that heterocyclic substitution, electron-donating groups, and hydrogen-bonding functionalities enhanced cytotoxic activity, whereas bulky aromatic systems and strong electron-withdrawing groups reduced potency. Molecular docking and in silico ADME studies supported the experimental findings and identified compound 4k as a promising candidate for further investigation. Full article

The transition towards a circular economy in the wastewater sector necessitates the sustainable management and valorisation of sewage sludge. This study provides a comprehensive longitudinal analysis of sewage sludge land application in Romania (2006–2024), contextualized within the broader Central and Eastern European (CEE) region (Poland, Czechia, Hungary, Bulgaria, and Slovakia; 2000–2024). Utilizing harmonized datasets from the Romanian National Institute of Statistics (INSSE TEMPO) and Eurostat, this research applies non-parametric Mann–Kendall trend tests, Sen’s slope estimator, Modified Trend-Free Pre-Whitening Mann–Kendall (TFPW-MK) tests to address serial autocorrelation, ordinary least squares regression with comprehensive residual diagnostics, exploratory detrended correlation matrices, and subperiod sensitivity analysis. Results indicate that Romanian municipal sludge applied to agricultural land increased from 0.38 thousand tonnes (kt) of dry matter (DM) in 2006 to a peak of 63.08 kt in 2022 and 53.97 kt in 2024 (+53.59 kt DM absolute increase; ~142-fold relative expansion), with the agricultural valorisation rate rising from 0.17% to a record 31.29% in 2024 (TFPW-MK Z = +5.000, p < 0.001). Municipal sludge production followed a non-linear trajectory, contracting to a historical minimum of 65.80 kt DM in 2012 before expanding to 283.34 kt in 2017 and reaching an infrastructural plateau around 172.49 kt in 2024 (2013–2024 subperiod τ = +0.030, p = 0.945). Conversely, reported industrial wastewater volumes experienced a substantial decline (TFPW-MK Z = −4.545, p < 0.001), reflecting industrial restructuring and a 2012/2013 reporting reclassification. Comparative CEE analysis reveals marked heterogeneity: Czechia (6.50 kg DM/capita) and Poland (4.07 kg DM/capita) lead in per capita agricultural recycling, while Romania reached 2.83 kg DM/capita (4.00 kg DM/ha Utilized Agricultural Area). An agronomic mass-balance assessment indicates that applying 53.97 kt DM under statutory limits requires a theoretical national land footprint of 10,794–17,990 ha (<0.133% of Romania’s agricultural area and <0.220% of conventional arable land), demonstrating that macro-scale physical land competition with certified organic farming does not exist. Furthermore, exploratory detrended and first-difference correlation analyses demonstrate that raw correlations between sludge and mineral fertilizers reflect parallel multi-decadal growth rather than guaranteed farm-level substitution. These empirical findings provide robust benchmarks for national circular sludge strategies under the recast EU Urban Waste Water Treatment Directive (Directive (EU) 2024/3019). Full article

This study develops an interpretable machine learning framework for predicting the 28-day compressive strength of recycled aggregate concrete containing supplementary cementitious materials and validates it experimentally using metakaolin and spent fluid catalytic cracking catalyst residue. A broad multi-source database was used to train K-nearest neighbors, support vector regression, random forest, extremely randomized trees, and extreme gradient boosting models, together with a stacked ensemble. The stacked model achieved the highest internal cross-validation performance, with an R² of 0.93. SHAP and partial dependence analyses identified cement content and water-to-binder ratio as the dominant predictors, whereas recycled coarse aggregate exerted a smaller effect conditioned by matrix quality. Independent experimental validation was conducted using two matched central composite designs produced with MK and FC3R under equivalent mixture-design conditions. MK consistently developed higher 28-day compressive strength than FC3R, with an average advantage of 6.06 MPa, while the predictive model reproduced the main material-specific trends for both systems. These findings confirm that 28-day strength is controlled by coupled binder–water–aggregate conditions and that interpretable ensemble learning can support preliminary mixture screening across distinct aluminosilicate systems within the investigated design domain. Full article

Background: Acute superficial venous thrombosis (SVT) presenting with clinical features of thrombophlebitis is increasingly recognized as a thromboinflammatory disorder in which innate immunity and coagulation are closely interconnected. Nonetheless, the role of endogenous antimicrobial peptides and heparin-binding growth factors in its pathogenesis is still inadequately comprehended. We investigated circulating dermcidin (DCD), ghrelin (GHR), heparin (HP), midkine (MK), and pleiotrophin (PTN) to explore their potential involvement in the thromboinflammatory network underlying SVT. Methods: In this prospective case–control study, 30 individuals with SVT and 28 healthy controls matched for age and sex were recruited. DCD, GHR, HP, MK, and PTN concentrations were quantified using enzyme-linked immunosorbent assays. Results: Patients with SVT exhibited significantly higher circulating DCD, GHR, MK, and PTN concentrations and significantly lower the measured HP concentration than healthy controls (all p < 0.05). Following LMWH treatment, the measured HP concentration increased significantly (p < 0.05), whereas DCD, GHR, MK, and PTN showed downward trends. Conclusions: Acute superficial venous thrombosis is associated with coordinated alterations in circulating the measured heparin, dermcidin, ghrelin, midkine, and pleiotrophin, reflecting a systemic thromboinflammatory biomarker profile. These findings suggest potential interactions among heparin biology, heparin-binding growth factors, and innate immune mediators but do not establish direct molecular interactions, heparin sequestration, functional depletion, or causality. This biomarker profile establishes a foundation for creating hypotheses for forthcoming investigations that include direct biochemical validation, standardized longitudinal sampling, and independent cohorts. Full article

Background: Glucose handling in hepatocyte-derived cells integrates insulin-responsive AKT signaling with GLUT1-mediated glucose transport, jointly regulating substrate trafficking, glycogen synthesis, and cell survival. MK-2206, a potent allosteric AKT inhibitor, and BAY-876, a highly selective GLUT1 inhibitor, represent targeted approaches to disrupt these processes. However, the consequences of simultaneous inhibition of both nodes in hepatocyte-derived cells remain incompletely understood. Objective: This study aims to evaluate the impact of simultaneous AKT inhibition and GLUT1 blockade on target engagement, cell viability, proliferation, cell death, glucose uptake, and glycogen storage in HepG2 cells. Methods: HepG2 cells were treated with MK-2206, BAY-876, or their combination under basal hyperglycemic and acute insulin-challenged conditions. Multi-model synergy, AKT/GLUT1 pharmacological effects, cell viability, proliferation, cell death, glucose uptake, and glycogen storage were assessed, alongside exploratory molecular docking analyses of both inhibitors against their respective targets. Results: Dual AKT and GLUT1 inhibition produced combination-specific reductions in cell viability and showed a pattern of concurrent antiproliferative effects and increased Annexin V/PI positivity without detectable caspase-3 activation under insulin-challenged conditions. Furthermore, the dual inhibition of AKT signaling and GLUT1-mediated glucose uptake produced combination-specific reductions in basal glycogen content, while glucose uptake reductions showed AKT-dominant patterns without significant combination superiority over MK-2206 alone under either metabolic state. Exploratory molecular docking of MK-2206 and BAY-876 against AKT1 and SLC2A1/GLUT1, respectively, generated computationally predicted binding poses consistent with the established binding modes of these inhibitors. Conclusions: Dual AKT/GLUT1 targeting produces endpoint-specific patterns of pharmacological interaction on insulin-responsive metabolism, proliferation, and cell death in HepG2 hepatocyte-derived cells, distinguishing combination-specific effects from AKT-driven effects. These findings support an endpoint-specific pharmacological framework in which AKT signaling and BAY-876-mediated GLUT1 pharmacological effects jointly influence glucose handling and cell fate in a hepatocyte-derived model. Full article

This study presents the development and comprehensive characterisation of a sustainable 3D-printable cementitious composition in which up to 40 wt.% of Portland cement was replaced by a ternary binder containing oil shale ash (OSA) and metakaolin (MK). Following laboratory optimisation, the developed formulations were successfully transferred to industrial production as pre-blended dry mixes at Sakret Latvia Ltd., demonstrating the feasibility of large-scale manufacturing of printable cementitious materials. Attention was devoted to the characterisation of the raw materials and dry mixtures using particle size distribution (PSD), scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS), and X-ray diffraction (XRD). Two compositions—a reference mixture (REF) and the ternary OSA mixture—were evaluated in terms of printability, mechanical performance, durability, and the influence of the type of sample production. The ternary composition (due to the pozzolanic activity of MK and OSA) exhibited strength development resulting in compressive strength (60.6 MPa) exceeding that of the reference mixture after 90 days of curing (55.3 MPa). Mechanical testing of compression and flexural properties indicated direction-dependent differences between printed and cast specimens. Durability assessment, including capillary water absorption and surface freeze–thaw scaling tests performed using two standardised methods, confirmed frost resistance and the suitability of both mixtures for outdoor applications. The results further indicate that the layered manufacturing process governs moisture transport and direction-dependent mechanical behaviour associated with interlayer interfaces. The developed pre-blended OSA–MK composite represents a promising low-carbon material for industrial 3D concrete printing, combining reduced cement consumption with reliable printability, mechanical performance, and durability. Full article

Metabolic-associated steatotic liver disease (MASLD) affects an estimated 25–30% of the global adult population and represents a leading cause of liver-related morbidity. However, approved pharmacological therapies remain strictly limited. AMP-activated protein kinase (AMPK), a highly conserved heterotrimeric serine/threonine kinase and major regulator of cellular energy homeostasis, is chronically suppressed in the steatotic liver through hyperinsulinemia, ceramide signaling, oxidative stress, and epigenetic silencing of its upstream activator LKB1. This suppression removes a critical brake on de novo lipogenesis while simultaneously impairing fatty acid β-oxidation, mitochondrial quality control, anti-inflammatory signaling, and hepatic stellate cell quiescence. Thus, AMPK restoration may serve as an effective strategy capable of addressing multiple pathological drivers of MASLD. This review examines the molecular architecture of the AMPK heterotrimer, the downstream signaling networks governing hepatic lipid metabolism, glucose homeostasis, and fibrogenesis, and a spectrum of AMPK-activating pharmacology relevant to MASLD. Furthermore, it would introduce indirect activators including metformin, berberine, resveratrol, and related phytochemicals, as well as direct allosteric activators targeting the ADaM site, such as A-769662, PF-06409577, MK-8722, Compound 991, and the clinical-stage compound O304. Translational challenges confronting this therapeutic class are critically evaluated. Full article

Automatic Dependent Surveillance-Broadcast (ADS-B) is one of the most critical technologies utilized in contemporary air traffic control, providing an automated and broadcast means of periodically sending aircraft identification and location, as well as velocity and other state-related information. This paper assesses the receiving performance of ADS-B signals utilizing multiple software-defined radio (SDR) platforms. Four different SDR platforms (DX Patrol MK4, Adalm-Pluto, USRP B200mini and USRP B210) were considered for evaluation, using a single antenna feed distribution via an active RF splitter. Each receiver’s performance was evaluated by measuring the rate at which each platform was able to decode messages from aircraft, the number of aircraft that were detected, the number of valid position reports received from each aircraft, the distance from the receiver to the aircraft at which each platform could receive valid position reports and each platform’s susceptibility to various forms of interference. The results indicate that the best cost-performance in case of interference-free ADS-B reception is obtained for the Adalm-Pluto platform (882 ADS-B messages received in the analyzed period, 2.84 cost/message), whereas the USRP B210 SDR exhibits the best performance in the presence of strong interference (109 ADS-B messages received). These findings provide insight into the relative trade-offs between low-cost SDR platforms and higher-performance SDR platforms, specifically related to analog-to-digital converter (ADC) resolution, RF front-end architecture, host interface, sensitivity and decoding reliability. Full article