Search Results (14,195)

This paper proposes a low weight hybrid battery–supercapacitor energy storage system interfaced with bidirectional DC/DC converters with high power/current capability for aircraft applications. The supercapacitor converter having high power uses two pairs of interleaved coupled inductors to reduce the overall current ripple whilst increasing the converter’s power density. Due to the sensitive performance to saturation of the coupled inductors, a phase current balancing strategy is proposed to counter the effect current imbalance in the channels that would cause saturation degrading overall performance. A power management strategy (PMS) is implemented along with a low pass filter to separate the supercapacitor high frequency power component reference from the battery low frequency power component; therefore, separating the energy and power requirement for the energy storage system contributing to minimizing its weight whilst ensuring the current/power stresses are correctly handled. The validity of the system design is validated by a series of transient tests is conducted both in a simulation model as well as experimentally. Full article

Puerto Rico has experienced increasingly frequent and intense extreme heat conditions in recent years, with the 2023–2024 warm seasons standing out for prolonged periods of dangerously high heat index values and widespread spatial exposure. These conditions are particularly concerning in tropical island environments, where high humidity limits physiological cooling and amplifies heat-related health risks. The main objective of this study is to identify and characterize extreme heat zones and events across Puerto Rico using NOAA-modeled heat index (apparent temperature) data, as well as to examine their spatial and temporal variability during the 2021–2024 period. Hourly modeled apparent temperature data between 2 and 4 pm, representing the warmest time of day, were analyzed for each day from June through October. Mean maximum and maximum heat index surfaces were generated for each month and warm season, and extreme heat zones were identified using the 103 °F (39.4 °C) danger threshold. Results show a persistent concentration of extreme heat in low-elevation coastal regions, particularly across the northern coastal plains from San Juan to Hatillo, with floodplain areas in Arecibo and Manatí exhibiting the highest and most consistent exposure. August was identified as the month with the highest mean maximum heat index across all study years, followed by September. The warm seasons of 2023 and 2024 exhibited the highest magnitudes and spatial extents of extreme heat, with some regions experiencing apparent temperatures exceeding 110 °F and up to 141 extreme heat days during peak afternoon hours. The findings indicate a transition from localized heat hotspots to widespread and sustained extreme heat exposure across Puerto Rico’s coastal regions. This study provides an island-scale assessment of extreme heat patterns with direct implications for public health, infrastructure planning, and heat-risk management in a warming tropical climate. Full article

Background: Premenstrual syndrome (PMS) significantly impacts daily functioning among women of reproductive age. Medical and nursing students face exceptional stressors that may exacerbate PMS, yet the interrelationships between sleep quality, perceived stress, and PMS remain understudied in Middle Eastern contexts. This study aimed to investigate the relationships between sleep quality, perceived stress, and self-reported PMS symptoms among Palestinian female medical and nursing students, to assess their prevalence and severity, and to examine variations across sociodemographic and lifestyle factors. Methods: This cross-sectional correlational study recruited 708 female medical and nursing students from three Palestinian universities. Validated Arabic instruments assessed sleep quality (PSQI), perceived stress (PSS-10), and PMS symptoms (A-PMSS). Analyses included Spearman’s correlations, non-parametric tests (Mann–Whitney U Test, Kruskal–Wallis Test), and multivariable linear regression. Results: Nearly all participants (98%) reported some degree of self-reported PMS symptoms at any severity level, with 76% experiencing moderate-to-severe symptoms. Poor sleep quality (PSQI > 5) affected 62.1%, while 94.5% reported moderate-to-high perceived stress. Significant positive correlations were identified between PSQI and PMS (rho = 0.295, p < 0.001) and between PSS-10 and PMS (rho = 0.483, p < 0.001). Multivariable regression revealed that perceived stress and sleep quality were significant independent predictors of PMS severity after adjusting for covariates, with the overall model explaining 27.5% of variance in PMS scores. Conclusions: This study reveals a substantial burden of PMS, poor sleep quality, and stress among Palestinian female medical and nursing students. Perceived stress and sleep quality were independently associated with PMS severity. These findings highlight need for integrated wellness programs in healthcare education for Palestinian students. Full article

Background and Objectives: The aim of this study is to assess the mismatch repair (MMR) status and immunohistochemical changes in cases of recurrent endometrial cancer following primary surgery and to evaluate the impact of these changes on prognosis. Materials and Methods: Thirty-one patients diagnosed with endometrial cancer who underwent surgery and had pathologically confirmed recurrences were evaluated. Changes in MMR protein expression, estrogen receptor (ER)/progesterone receptor (PR), and p53 expression in primary surgery and recurrent tumor tissues were assessed using immunohistochemical methods. Prognostic factors influencing these parameters and survival data were investigated. Results: In the assessment of recurrent materials, there were four cases where the MLH-1&PMS-2 staining status changed from intact to loss and four cases that changed from loss to intact. No changes were observed in regard to MSH-2 &MSH-6 staining. The ratios of pMMR and dMMR following the primary surgery were 55% (n = 17) and 45% (n = 14), respectively. Four cases transitioned from pMMR to dMMR, and four cases transitioned from dMMR to pMMR. After recurrence, changes in the ER, PR, and P53 status were observed in seven, three, and three patients, respectively. Conclusions: Changes in the MMR status, receptors, and P53 were observed. It is necessary to re-evaluate prognostic parameters via biopsies in recurring cases and to adjust rescue treatments accordingly. Full article

Pathogenesis-related protein 1 (PR1) plays important roles in plant responses to both biotic and abiotic stresses; however, its role in mediating defense against pine wood nematode in Pinus massoniana remains unclear. In this study, a total of 63 PR1 family members were identified in P. massoniana using bioinformatics approaches and were named PmPR1-1 to PmPR1-63 based on their phylogenetic relationships. Phylogenetic analysis showed that these members were distributed among four of the six subfamilies. Most of the encoded proteins were hydrophilic, with lengths ranging from 131 to 406 amino acids. Their promoter regions contained multiple cis-acting elements associated with phytohormone signaling and stress responses, and some members formed gene clusters on chromosomes 2, 5, and 9. qRT-PCR (quantitative reverse transcription polymerase chain reaction) analysis showed that the clustered genes PmPR1-46, PmPR1-55, PmPR1-56, and PmPR1-61 were significantly upregulated in the early stage of pine wood nematode inoculation in both resistant and susceptible P. massoniana plants, with higher expression levels in resistant plants. Transient overexpression of PmPR1-61 increased SOD and PPO activities as well as proline content while decreasing CAT activity. These results suggest that the PmPR1 family may be involved in the defense response of P. massoniana against pine wood nematode. Among them, PmPR1-55, PmPR1-56, and PmPR1-61 represent candidate resistance genes worthy of further investigation and provide valuable gene resources for elucidating resistance mechanisms and supporting molecular breeding in P. massoniana. Full article

Air pollution poses a major public health threat, yet longitudinal evidence on its impact on infant health-related quality of life (HRQoL) remains limited. This study investigated the longitudinal associations between early-life exposure to outdoor air pollution and infant HRQoL, focusing on psychological and physiological domains. Between November 2021 and September 2022, 779 mother–newborn pairs were recruited, with 696 completing follow-up at 12 months. HRQoL was assessed at 1, 4, 6, and 12 months using the Pediatric Quality of Life Inventory™, and exposures to PM_2.5, PM₁₀, NO₂, and SO₂ were analyzed using linear mixed-effects models adjusted for infant sex, household income, sibling status, and other covariates. Higher concentrations of all pollutants were associated with lower total HRQoL scores. Stratified analyses showed that PM_2.5, PM₁₀, and SO₂, but not NO₂, were associated with steeper age-related declines in total scores. Inverse associations with psychosocial health were consistent across pollutants, with pronounced age-related declines in high-exposure groups; for physical health, only SO₂ and NO₂ remained significant after adjustment, with modest age-related changes. These findings suggest that early-life air pollution exposure is associated with smaller gains in HRQoL during infancy, particularly in psychosocial well-being, highlighting the importance of improving air quality to support early development. Full article

Accurate diagnosis of PM and precise histologic subtyping are critical for optimal therapeutic decision-making, as treatment strategies—including chemotherapy, immunotherapy, or multimodality approaches—are largely subtype-dependent. Because of the several-decade latency between fiber inhalation and symptom onset, many cases are diagnosed at an advanced stage, when patients are already in poor clinical condition. As observed across multiple solid malignancies, earlier-stage diagnosis is associated with improved prognosis and expanded therapeutic options. However, the rarity of PM, the absence of validated screening strategies, and its nonspecific clinical and radiologic presentation—often mimicking both benign and metastatic pleural conditions, frequently result in diagnostic delay. Furthermore, the lack of pathognomonic histopathologic markers further complicates timely and definitive diagnosis. This review aims to delineate the epidemiologic, clinical, radiologic, and pathologic barriers that hinder accurate and early detection of PM. Current clinical evidence points to an urgent need to develop novel, validated biomarkers in PM, which will require a multidisciplinary approach. Full article

Construction projects contributing to smart city (SC) development largely consist of megaprojects due to their complex and multidisciplinary nature and their high costs. Effective project management (PM) is essential for the implementation of these projects in the Construction 5.0 era. This study aims to systematically analyze the research trends and identify FRDs in construction PM for megaprojects, which are essential for the development of SCs in the Construction 5.0 era. With this aim, a systematic literature review based on the PRISMA 2020 checklist was performed through a bibliometric analysis using VOSviewer version 1.6 Studies are gathered under five main clusters (i.e., the PM cluster, the smart construction and data security cluster, the SC and technology cluster, the spatial data integration cluster, and the lifecycle cluster). It has been determined that two main nodes (i.e., SC and digital twin) are located at the center of all these clusters. As a result of the analysis, two future research directions are determined (i.e., the relationship between megaprojects and SCs and the relationship between construction project management and SCs). As the identified clusters, nodes, and future research directions are interrelated and comply with the PMBOK 7th edition performance domains, focusing on them to support construction PM performance complies with efforts to facilitate the successful implementation of megaprojects integrated with SCs. The findings demonstrate the lack of a PM model within the SC ecosystem that synchronizes all phases of megaproject construction with SCs. Thus, this study can contribute to the development of smart, sustainable, and resilient cities. Full article

The transformation of university libraries into learning commons has highlighted the importance of informal learning spaces (ILSs). However, the mechanisms through which spatial elements influence learning experiences remain underexplored, particularly in western China. Drawing on person-environment fit theory and a multi-coupling framework, this study develops a four-dimensional analytical model comprising spatial layout, facility configuration, environmental quality, and cultural perception. A mixed-methods approach was employed, including 532 valid questionnaires, behavioral observations, and comprehensive environmental measurements (illuminance, noise, CO₂, PM2.5, TVOC, thermal conditions) across three university libraries in Lanzhou, China. Structural equation modeling (SEM) and coupling coordination degree modeling were used for analysis. Spatial layout (β = 0.324, p < 0.001), facility configuration (β = 0.287, p < 0.001), environmental quality (β = 0.196, p < 0.01), and cultural perception (β = 0.158, p < 0.05) all significantly predicted learning satisfaction, jointly explaining 67.3% of the variance. Learning satisfaction partially mediated the relationship between spatial elements and learning outcomes (indirect effect 31.2%). Coupling coordination degrees ranged from 0.578 to 0.634, revealing a “high coupling, low coordination” pattern, with cultural perception as the common shortfall. Environmental measurements showed CO₂ concentrations ranging from 823 to 946 ppm in quiet zones and up to 1085 ppm in lounge areas, correlating negatively with satisfaction (r = –0.41, p < 0.05). Spatial elements influence learning outcomes primarily through satisfaction enhancement. An integrated optimization framework is proposed, offering actionable strategies for ILS design in similar contexts. Full article

Virtual coupling control of trains is a promising technology for improving railway capacity and operational efficiency. However, existing multi-agent reinforcement learning (MARL) approaches struggle to capture long-sequence temporal dependencies among train states in complex multi-train interaction scenarios, resulting in limited robustness and coordination stability. To address this issue, this paper proposes a Predictive Mamba-based Multi-Agent Soft Actor–Critic (PM-MASAC) framework. A Mamba-based state prediction module is embedded into the centralized Critic network to model historical state sequences and generate predictive state representations, thereby enhancing value estimation accuracy. In addition, a multi-agent aggregated prioritized experience replay (PER) mechanism is introduced to improve the utilization of critical cooperative samples and stabilize training. A hierarchical local–global reward structure is further designed to ensure individual tracking performance while promoting overall formation coordination. Experimental results under realistic railway operating conditions demonstrate that PM-MASAC achieves superior robustness compared with baseline MARL methods. Velocity and spacing tracking errors are maintained within 3% and 1%, respectively, and the steady-state formation success rate exceeds 95.7% in the training environment. Full article

The synthesis of nitrogen-containing heterocycles remains a subject of significant interest due to their applications in medicinal chemistry and materials science. This paper describes the preparation of imidazo[1,2-a]pyridine using a catalytic system consisting of the deep eutectic solvent (DES) choline chloride (ChCl)–tartaric acid (1:2) and I₂ by reaction between 2-aminopyridines and chalcones (1,3-diphenylprop-2-en-1-ones). The proposed mechanism suggests the activation of the chalcone carbonyl by the DES, enhancing the polarization of the conjugated system which suffers electrophilic addition by I₂ to the C=C bond. The resulting intermediate undergoes a nucleophilic attack by 2-aminopyridine followed by cyclization and iodine-promoted oxidation and aromatization to yield the corresponding imidazo[1,2-a]pyridine products. The role of the DES is crucial, as it facilitates carbonyl activation through hydrogen bond interactions, stabilizes reactive intermediates, and promotes protonation–deprotonation steps, thereby eliminating the need for metal catalysts or toxic organic solvents. Theoretical calculations at the PM6 level of theory suggest that the DES acts as a catalyst in this reaction, due to the nature of its components enabling the development of more sustainable synthetic strategies. Full article

This work investigates the behavior of carbon dioxide (CO₂) near the surface of different single-atom alloys to evaluate their potential as catalysts for decarbonization processes. Specifically, 26 transition metals from the first three transition series, alloyed with three low Miller index copper supports, were considered. Adsorption energies and distances of linear CO₂, trigonal CO₂, and CO* + O* on the surfaces were calculated using the semiempirical computational method MOPAC-PM7. Additionally, activation energies were determined from previously published research. The proposed methodology is less computationally demanding than DFT studies, and results show good agreement with both experimental and simulated data. This approach provides a computationally efficient methodology for screening promising materials that convert CO₂ into valuable products, such as methane and methanol. Full article

As a core decarbonization technology, the scaling up of Near-Zero Energy Building (NZEB) technologies under the “dual carbon” goal necessitates collaboration among governments, technology suppliers, and construction enterprises. However, high research and development (R&D) costs coupled with low market acceptance impede widespread adoption. This study develops a tripartite evolutionary game model to analyze strategic interactions among stakeholders. Using MATLAB 2022B simulations, we simulate the strategy sets for the government (subsidize/no subsidy), suppliers (R&D/no R&D), and enterprises (procure/no purchase). The results identify two Evolutionary Stable Strategies (ESS): a market-driven ESS (0, 1, 1) emerges when the green premium (Pm) exceeds the incremental cost (Cb); while a policy-driven ESS (1, 1, 1) requires government subsidies (S) to offset R&D gaps, specifically when $S>Cr/\alpha -Pmz$. These findings provide a theoretical basis for understanding the synergistic mechanisms underlying NZEB adoption and highlight the dynamic interplay between policy incentives and market forces. Full article

Accurate forecasting of near-surface PM_2.5 concentrations remains challenging due to the complex coupling between atmospheric vertical structure, thermodynamic stability, and pollutant accumulation processes. Most existing surface-based statistical and deep learning approaches struggle to represent the three-dimensional state of the atmosphere, which limits their robustness under complex meteorological conditions. In this study, we propose a multi-source spatiotemporal learning framework(MST-Net) to enhance PM_2.5 forecasting accuracy by integrating vertically resolved atmospheric information from lidar and radiosonde observations. The proposed approach incorporates vertical profile features together with surface measurements to provide complementary information on atmospheric vertical structure and its temporal evolution. Experimental results demonstrate that MST-Net consistently outperforms conventional time-series models across multiple forecast horizons. Notably, at extended lead times (12–24 h), the proposed framework exhibits enhanced stability and slower error growth. For 24 h forecasts, MST-Net reduces RMSE by approximately 13% and MAE by about 19%. These results indicate that leveraging multi-source vertical atmospheric information can effectively improve the reliability of urban air quality forecasting. Full article

To address water-heat constraints and environmental risks associated with plastic film mulching in winter wheat production in the semi-arid region of Northwest China, a two-year field experiment (2021–2023) was conducted in Tongwei County, Gansu Province. A single-factor randomized block design was applied, with full plastic film mulching (PM) and bare land (CK) as controls, to evaluate the effects of 3-row (S3), 4-row (S4), and 5-row (S5) corn stalk strip mulching on soil hydrothermal conditions, active carbon fractions, and yield under rainfed conditions. Results showed that straw mulching significantly enhanced soil water retention, particularly in the 0–40 cm layer, where moisture content increased by 7.70–19.28% compared with CK (p < 0.05), with S3 performing best. Treatment S5 achieved the highest accumulated temperature and reduced the soil diurnal temperature range by 20.73–35.62% (p < 0.05). Active carbon fractions were also significantly improved, especially during the jointing–grain-filling stage (BBCH 31–87). In terms of yield, S5 exhibited the greatest increase, with a 15.88% higher two-year average grain yield than CK (p < 0.05), reaching over 90% of PM. Overall, S5 demonstrated optimal synergistic regulation of water, heat, and carbon, indicating strong potential as a sustainable alternative to plastic film mulching. Full article