Search Results (4,285)

Under the fast development of urbanization, PM_2.5 pollution has become a prominent issue affecting the urban ecological environment and residents’ health. To investigate the impact of urban landscape patterns on PM_2.5 concentrations, this study applies the Local Climate Zone (LCZ) classification to Shanghai using the World Urban Database and Access Portal Tools (WUDAPT). LCZ-derived landscape metrics are adopted as predictor variables to focus on how urban form and spatial configuration affect PM_2.5 distribution and to identify the key landscape categories and types influencing PM_2.5 levels. The results reveal notable seasonal and spatial differences in the effects of different LCZ types and landscape metrics on PM_2.5 concentrations; on average, over 69% of the spatial variation in PM_2.5 across the four seasons can be explained by the Multi-scale Geographically Weighted Regression (MGWR) model. This research demonstrates that the LCZ framework effectively uncovers the seasonal and spatial mechanisms by which urban landscape patterns influence PM_2.5 concentrations in Shanghai. It offers a novel perspective for understanding the interplay between urban landscape and atmospheric pollution, and provides scientific guidance for sustainable urban planning and precise air pollution control strategies in other cities. Full article

The neurovascular unit (NVU) is an essential, dynamic multicellular unit that maintains the homeostasis and function of the brain, with the integrity of the NVU having a tremendous impact on the pathogenic progression of ischemic stroke (IS). MicroRNAs (miRNAs) are essential regulators of gene expression and promote intercellular communication and functional unity in the NVU. This narrative review assesses the regulatory process mediated by miRNAs that help maintain homeostasis of the NVU, particularly during IS, with particular emphasis on their modulation of tight-junction (TJ) proteins, basement membrane (BM) and glial–vascular. These regulatory actions are essential for blood–brain barrier (BBB) integrity and neuronal survival. The analysis also exposes the intercommunication networks established by key miRNAs between various cells of the NVU, highlighting their complex and dynamic regulatory properties. Moreover, it investigates therapeutic strategies predicated on miRNA regulatory mechanisms, highlighting the optimistic prospects as well as the present limitations pertaining to effective IS intervention. Full article

Organic photovoltaic materials and nonlinear optical materials share inherent commonalities in molecular characteristics—such as strong light absorption, high charge carrier mobility, and tunable energy levels. Therefore, this study selects a bithiophene-fused ring system with photovoltaic application potential as the research subject. Using TTTTB6-2CHO (TB1) and IDTTB6-2CHO (TB2) as comparative molecules, their nonlinear optical properties in the near-infrared region were systematically investigated. Transient absorption spectroscopy results demonstrate that TB1 exhibits strong and persistent excited-state absorption within the spectral range of 650–900 nm, endowing it with excellent two-photon absorption performance (a cross-section of up to 5591 GM at 650 nm) and an ultralow optical limiting threshold (0.00147 J/cm² under 800 nm femtosecond laser irradiation). The findings of this study not only confirm the feasibility of developing nonlinear optical materials from photovoltaic candidate molecules but also highlight the effectiveness of the “thiophene-for-benzene substitution” strategy in significantly enhancing optical nonlinearity. These results provide valuable design principles for the development of multifunctional organic optoelectronic materials, particularly for application scenarios such as laser protection. Full article

The ponyfish genus Nuchequula is presents taxonomic challenges within Leiognathidae due to morphological complexities and a lack of genomic resources. However, the absence of a complete mitochondrial genome for Nuchequula longicornis has hindered comprehensive phylogenetic comparisons. Here, we employed an integrative approach combining detailed morphology with molecular validation via 16S rRNA gene sequencing to confirm the identity of specimens from the Beibu Gulf. Furthermore, we present the first complete mitogenome of N. longicornis. This circular 16,514 bp molecule exhibits a typical gene order, a moderate AT bias (54.8%), and strong purifying selection across all protein-coding genes. Phylogenomic analysis based on the complete mitogenome reliably resolved the position of N. longicornis within Leiognathidae, contributing to the discussion on the phylogenetic relationships and potential monophyly of Nuchequula and contributing to the understanding of intra-familial relationships. Our study provides an essential mitogenomic resource for N. longicornis and offers insights into mitochondrial evolutionary patterns within this family. Full article

This study aims to develop a strategy for practical real-time applications in Plug-in Hybrid Electric Vehicles (PHEVs). The study combines a Blending Control Scheme (BCS) with an Equivalent Consumption Minimization Strategy (ECMS) for energy management. During the charge-depleting (CD) mode, a blending control scheme was employed, in which the electric motor served as the primary propulsion source while the engine was selectively engaged to share the load. Within this framework, ECMS was applied to determine the optimal power split between the engine and the electric motor in real time. The ECMS considers both the energy consumed by the electric motor and engine to achieve optimal energy consumption, converting the motor and generator consumed electrical energy into an equivalent fuel consumption and combining it with the internal combustion engine’s fuel consumption to determine the equivalent fuel consumption for each time step, then minimizes this equivalent fuel consumption. A backward, instead of forward, PHEV model was built in MATLAB/Simulink based on the THS. The results of combining BCS and ECMS were compared with those of the Rule-Based Control Strategy, which served as the baseline for comparison. The Toyota Hybrid System (THS) was used. The standard FTP-75 driving cycles, including urban and highway scenarios, were simulated. Results show that the Rule-Based strategy has an equivalent combined fuel economy of 50.7 miles per gallon (MPG-e). The proposed method, combining BCS and ECMS, achieves 56.33 MPG-e, representing an approximately 11.1% improvement over the Rule-Based strategy. BCS and ECMS allowed the engine to engage effectively at the adequate time in its high-efficiency region, as well as the motor throughout the drive cycle, and enabled more refined coordination of engine and electric power sources, and can provide high-efficiency computation to realize real-time optimization-based control. Full article

Incremental electromagnetic signal classification is crucial in realistic wireless environments where new signal types continuously emerge and historical training data are often unavailable. This paper proposes a model-based incremental learning method driven by vector space separation to mitigate catastrophic forgetting without accessing old-task samples or requiring semantic information. We show that forgetting is largely caused by insufficient separation between old and new classes in the classifier weight space. To address this issue, we jointly introduce weight normalization, a cosine-similarity separation loss, and regularization, together with cross-entropy supervision for new classes. Based on these designs, we propose an incremental learning method based on vector space separation for electromagnetic signal classification, enabling the model to continually recognize modulation signals without requiring semantic information or access to raw data from previous tasks during incremental updates. Experiments on two simulated modulation datasets under multiple task sequences demonstrate that the proposed method consistently alleviates catastrophic forgetting and achieves stable incremental performance, outperforming baselines while avoiding data rehearsal. Full article

In this paper, the time-dependent properties of the elastic modulus of fly ash concrete under sustained compressive load were studied. An experiment was conducted and showed an increment of elastic modulus for two types of fly ash concrete (20% and 40% fly ash replacement) under sustained load. The mechanisms of this increment were analyzed, and two Representative Volume Elements (RVEs) were established to represent the micro-heterogeneous space of binder and concrete based on continuum mechanics. The shrinking core models of hydration and pozzolanic reaction were adopted to quantify the volume fraction of each phase within the binder RVE. A prediction model was proposed by incorporating the effects of extra hydration and time-dependent aggregate concentration rate under sustained load. Finally, parameter analysis including the influences of initial loading age and the loading level was conducted. Full article

Alterations in mitochondrial fusion and fission dynamics are critical determinants of cellular fate. However, how stress-induced mitochondrial fusion and fission affect the physiological and pathological processes in cardiomyocytes remains poorly understood. Based on an established in vitro model of stress-induced cardiomyocyte injury using isoproterenol-treated H9c2 cells, this study aimed to investigate whether the dysregulation of mitochondrial dynamics—specifically, an imbalance between fusion and fission—activates the IRE1α-ASK1-JNK endoplasmic reticulum stress signaling pathway, thereby contributing to cardiomyocyte damage. Under this experimental paradigm, cell viability was evaluated using the CCK-8 assay. Concurrently, immunofluorescence staining was employed to assess reactive oxygen species accumulation, the expression of key mitochondrial fusion/fission proteins, and components of the ER stress pathway (IRE1α, ASK1, and JNK). Results demonstrated that isoproterenol treatment elevated intracellular ROS levels and induced significant changes in both mitochondrial dynamics-related proteins and the IRE1α-ASK1-JNK signaling axis. In contrast, administration of the mitochondrial fission inhibitor Mdivi-1 attenuated ROS accumulation, restored the expression of the affected proteins toward normal levels, and alleviated cardiomyocyte injury. Collectively, these findings indicate that the disruption of mitochondrial fusion/fission dynamics triggers endoplasmic reticulum stress via the IRE1α-ASK1-JNK cascade, which participates in the pathological progression of cardiomyocyte injury. Full article

The deep brine reservoirs in the Jianshishan area of the Qaidam Basin are abundant in strategic mineral resources. Traditional extraction methods suffer from insufficient reservoir energy and low recovery efficiency, while CO₂ flooding technology offers a new solution integrating brine development and CO₂ sequestration. However, the reservoir comprises three typical lithologies (calcareous mudstone, laminated mudstone, and massive sandstone) with distinct mineral compositions and structural characteristics and the mechanisms by which CO₂–brine–reservoir reactions affect their pore structures remain unclear. This study conducted laboratory simulation experiments combined with multiple analytical techniques to investigate the evolutionary characteristics of the three lithologies under CO₂ action. The results show that (1) calcareous mudstone has the strongest dissolution effect, with porosity increasing from 6.25% to 9.29% (an increase of 48.6%) and permeability increasing from 0.0012 mD to 0.0511 mD (an increase of 41.6 times); (2) laminated mudstone shows a trend of “first improvement, then deterioration”, with porosity initially rising to 11.84% and then slightly decreasing, and permeability decreasing from 0.0042 mD to 0.0036 mD; and (3) massive sandstone has stable mineral composition, with porosity increasing from 10.74% to 11.63% (an increase of 8.3%) and permeability fluctuating slightly between 0.0028 and 0.0032 mD. This study reveals that lithological mineral composition and structural characteristics are core factors controlling pore structure evolution, providing theoretical and experimental support for optimizing differentiated CO₂ flooding schemes for deep brine reservoirs. Full article

Urban heat not only affects thermal comfort but also constrains the sustainable development of cities, underscoring the necessity of understanding the temporal response of land surface temperature (LST) to urban characteristics over time. Most existing studies rely on single-overpass satellite observations or daily averages, failing to capture continuous diurnal variability and the time-dependent influence of different drivers. In this study, we reconstructed seasonal hourly LST series for Beijing using an improved diurnal temperature cycle (DTC) model (${\mathrm{GEM}}_{\eta }$) based on MODIS data, and employed a random forest framework to quantify the relative contributions of natural, urban morphological, and anthropogenic factors throughout the diurnal cycle. Unlike previous studies that rely on traditional DTC models and machine learning for largely static or single-scale assessments, our research provides a unified, time-explicit comparison of LST driver dominance across seasons, hourly diurnal cycles, and urban–rural contexts. The results indicate that persistent urban heat island (UHI) effects occur in all seasons, with the maximum intensity reaching approximately 5.0 °C in summer. Generally, natural factors exert a cooling influence, whereas urban morphology and human activities contribute to warming. More importantly, the dominant drivers show strong temporal dependence: a nature-dominated regime prevails in summer, where vegetation exerts an overwhelming cooling effect. Conversely, during transition seasons and winter, LST variability is governed by a mixed-driven mechanism characterized by an hourly-resolved diurnal handoff, in which the dominant contributors shift hour by hour between surface physical properties and anthropogenic proxies. Our findings challenge the static view of urban heat drivers and provide quantitative evidence for developing time-sensitive and seasonally adaptive mitigation strategies, thereby supporting sustainable urban planning and enhancing climate resilience in megacities. Full article

Acute lung injury (ALI) is a clinically severe respiratory disorder, of which autophagy is the crucial mechanism. Exosomes have the potential to treat ALI, but the role of adipose-derived exosomes (ADEs) in the autophagy of ALI remains unclear. Using an LPS-induced ALI model, the effects of ADE isolated from a lean or diet-induced-obese (DIO) mouse and ADE-carried miRNAs were investigated. After administration of ADEs, the levels of autophagy-related molecules were determined by qRT-PCR, Western blotting, and immunohistochemical staining. Then, a miRNA targeting HMGB1 was screened by bioinformatic analysis and a dual-luciferase reporter assay, and its effect on the HMGB1-driven autophagy in an ALI mouse was investigated as ADEs. The data showed that LPS caused lung injury and activated HMGB1-driven autophagy. The ADEs from a lean mouse or DIO mouse significantly alleviated histopathological lesions, and they inhibited HMGB1-driven autophagy by down-regulating LC3, Beclin-1, and Atg5; the effects of ADEs were not significantly different between a lean and DIO mouse. Of the miRNAs carried by ADE, moreover, miR-142a-3p could specifically bind to HMGB1 mRNA, and up-regulation of pulmonary miR-142a-3p suppressed HMGB1-driven autophagy and relieved lung injuries. Our results indicated that miR-142a-3p and ADEs mitigate LPS-induced ALI by inhibiting HMGB1-driven autophagy, providing new insights on the prevention and treatment of ALI. Full article

The frequency regulation problem of the power system under the scenario of a high proportion of new energy access has attracted attention. It has become an important technical means for new energy to reserve a certain amount to participate in system frequency regulation. Reserve capacity, response speed, and regulation rate jointly determine the post-disturbance frequency trajectory of the system. This paper briefly compares the primary frequency regulation control performances of wind power generation, photovoltaic power generation and thermal power generation, analyzes the influence of factors such as frequency distribution, regulation rate, frequency regulation capacity and frequency deviation on primary frequency regulation, and, considering the need for rapid frequency response in power systems with a high share of new energy, taking into account the system frequency response performance and new energy consumption demand, a method for optimizing the reserve configuration of new energy power generation for primary frequency regulation is proposed. Simulation analysis is carried out using a simplified actual power system, and the results show that an appropriate reserve provided by new energy helps the system frequency recover quickly. Full article

Background/Objectives: Bereavement in childhood, adolescence, and young adulthood is associated with a range of grief responses, and a subset of bereaved individuals develop persistent or severe grief symptoms. Understanding the prevalence and risk factors of prolonged grief symptoms is important for guiding supportive care. Methods: We systematically searched PubMed, MedLine, Embase and PsycINFO for all studies comparing the prevalence and prognostic factors of prolonged grief-related symptoms among young individuals following parental or sibling death from cancer. Young individuals were defined as those not more than 25 years old before losing a parent or sibling to any cancer. Prolonged grief-related symptoms were defined as the presence of grief symptoms at least six months following the death of a parent or sibling of the bereaved person. Retrospective cross-sectional studies were included for evaluating prognostic factors affecting prolonged grief-related symptoms, but were not used for meta-analyses. Random-effects meta-analyses were conducted for the primary analysis. Results: From 1561 records identified, thirteen studies were included with five for quantitative pooling in meta-analysis. The pooled prevalence of self-reported prolonged grief-related symptoms was 48% (95% CI: 29–67%). Stratified analyses suggested a prevalence of 28% (95% CI: 7–65%) after parental death and 59% (95% CI: 45–72%) after sibling death. Factors associated with elevated prolonged grief-related symptoms included pre-existing depression, emotional difficulties, and insomnia. As no included studies conducted diagnostic clinical interviews, prolonged grief disorder according to the ICD-11 or DSM-5-TR criteria could not be assessed. Conclusions: Prolonged grief-related symptoms appear common among young individuals bereaved by loss of a parent or sibling to cancer, especially after sibling loss. However, interpretation remains limited by substantial heterogeneity, such as outcome measures, symptom thresholds, assessment time window, non-validated symptom measures, and predominance of cross-sectional studies. Future larger and methodologically rigorous studies using validated grief instruments across diverse settings are needed to clarify grief trajectories and guide developmentally appropriate intervention strategies. Full article

In remote sensing and low-altitude unmanned aerial vehicle(UAV) detection scenarios, small target detection is extremely challenging due to the low pixel proportion, sparse features, and complex backgrounds of targets. The reliability of low-altitude security, in particular, is directly dependent on the accuracy of small target detection. However, current methods still face three major limitations: insufficient detection accuracy for targets smaller than 20 pixels; artifacts and false textures introduced by Generative Adversarial Network-based enhancement, which lead to increased false detection rates; and the reliance of existing approaches on specialized architectures, resulting in weak generalization capability and difficulty in adapting to multi-scenario deployment requirements. To address these issues, this paper proposes a plug-and-play dual-mechanism collaborative enhancement framework named HD-BSNet. Firstly, a High-Frequency Differential Perception mechanism is designed to enhance the detailed feature representation of small targets. Secondly, a Background Semantic Modeling mechanism is introduced to learn key features that distinguish targets from the background. Additionally, a Parallel Multi-Scale Focus Module is constructed to further reinforce target features. Extensive experiments on three small target datasets demonstrate that the proposed method effectively improves the accuracy and generalization ability of small target detection. Full article

Diamond has been extensively examined as an appealing material for use in quantum optics and quantum information processing owing to the existence of various classes of optically active defects, referred to as “color centers,” which can be engineered into its crystal structure. Among these defects, the negatively charged nitrogen-vacancy center (NV⁻) stands out as the most prominent type. Despite the progress made, the number of emitters characterized by reproducible fabrication processes within the desired spectral range at room temperature, with limited or no damage to the parent diamond lattice, remains restricted. Herein, we are proposing for the first time the creation of the FV⁻ center in diamond via low-energy implantation, which is particularly interesting as it possesses characteristic light absorption and magnetic properties similar to NV⁻ centers. The low-energy ion-implanted FV centers in diamond show more desirable optical emission properties at room temperature (RT). Additionally, as per DFT calculations, the flat bands near the Fermi energy indicate dominant electron–electron interactions, an important prerequisite for observing emergent behavior as seen in systems such as twisted bi-layer graphene. Consequently, as-developed new luminescent defects such as Fluorine Vacancy Centers (FV) with desirable spectral and quantum emission properties would be a significant breakthrough in diamond-based quantum materials. Full article