Search Results (7,459)

The large-scale integration of renewable energy has significantly improved the low-carbon performance of power systems, but has also increased operational uncertainty. Under extreme weather conditions, wind and solar power may experience consecutive days of simultaneous output shortfalls—referred to as “renewable energy drought”—leading to persistently high net load and severe challenges to supply guarantee. To address this issue, this paper proposes a multi-source coordinated supply-guarantee dispatch strategy for consecutive-day renewable energy drought scenarios. First, net load is defined as the total system load minus the available wind and solar output. Based on magnitude and duration thresholds, renewable energy drought events are extracted from historical data to generate representative scarcity scenarios. Second, a multi-source coordinated optimization dispatch model is constructed, incorporating wind power, solar power, thermal units, battery energy storage, and pumped-storage hydro. The objective is to minimize the total system operating cost, which includes thermal fuel cost, start-up/shut-down costs, storage cycling cost, wind/solar curtailment penalty cost, and load shedding penalty cost. The load shedding penalty coefficient is set to a magnitude much higher than conventional costs to highlight the priority of supply guarantee. The model accounts for operational constraints such as minimum up/down times, deep regulation capability, ramping limits of thermal units, and charge/discharge power limits of storage. Taking a provincial power system in China for the year 2030 as a case study, a dispatch case covering four consecutive days (96 time periods) is designed. Based on a baseline scenario, eight groups of sensitivity analyses are conducted to comprehensively investigate the impacts of key factors on the supply-guarantee strategy, including: the minimum up/down time of thermal units, deep regulation capability, load shedding penalty cost, load level, rated energy capacity and charge/discharge efficiency of battery energy storage, rated energy capacity and pumping/generating efficiency of pumped-storage hydro, thermal fuel cost coefficient, and renewable energy capacity. Simulation results show that the proposed strategy can effectively coordinate multiple resources under consecutive-day drought conditions; reducing the minimum up/down time of thermal units improves supply flexibility but increases start-up/shut-down costs; enhancing deep regulation capability optimizes storage utilization and reduces total system cost; the load shedding penalty cost directly determines the trade-off between supply guarantee and economic efficiency; and as load level decreases by 5%, 10%, and 15%, the total system operating cost reduces by approximately 6.3%, 12.5%, and 18.8%, respectively. This study provides a quantitative method and technical support for supply-guarantee dispatch decisions and resource allocation in high-renewable power systems under persistent drought conditions. Full article

Turbofan engine performance is critically sensitive to operating conditions, yet comprehensive frameworks that simultaneously assess exergo-economic, exergo-environmental, and lifecycle cost performance across realistic flight envelopes remain limited, particularly for Gulf-region climates. In this study, we present a comprehensive analysis of the exergo-economic, exergo-environmental, and lifecycle costings of five different configurations of two-spool and triple-spool turbofan engines. The analysis was carried out for a wide range of four operating conditions, namely ambient temperature, flight altitude, Mach number, and % relative humidity, with emphasis on the climate conditions likely to be found in the Gulf region. The computational models developed were validated against published data to confirm their reliability. It was found that fuel consumption was the most significant contributor to total lifecycle ownership cost, between 60 and 75% of hourly operating cost over a 20-year service period. Ambient temperature, Mach number, and Cruise altitude represented the most significant drivers of long-term economic performance, with % relative humidity having little effect. Exergo-economic analysis showed that the major cost mechanisms changed dramatically with operating conditions. Exergy destruction and component inefficiencies determined the costs at Takeoff, with capital investment being the dominant factor when cruising. Increase in both or either ambient temperature and altitude was shown to reduce cost rates but simultaneously reduced thermo-economic efficiency via higher specific exergy costs. However, increase in Mach number enhances both exergy output and cost-effectiveness, confirming that specific exergy cost is a more reliable indicator of true system performance than cost rate alone. The two-spool configurations show superior specific CO₂ emissions, with Case 3 recording the lowest emissions at Takeoff and Case 2 at Cruise. For exergy-based environmental indicators, Case 3 performs best at both Takeoff and Cruise, achieving the lowest environmental destruction coefficient and index, as well as the highest environmental benign index among all five configurations. These findings provide actionable guidance for engine selection, operational optimization, and sustainable propulsion system design. Full article

Foreign Direct Investment (FDI, hereafter) as a determinant of economic growth has received significant attention in both the theoretical and empirical research literature due to its numerous benefits. However, the FDI–growth relationship is rarely researched for the economy of Saudi Arabia. Amid this backdrop in the literature, this paper focuses on Saudi Arabia to provide fresh, comprehensive evidence about the FDI–growth relationship. Our analysis is based on time series data for the period 1975–2023, which were collected from credible global sources. For estimation, the study adopted ARDL modeling, which is suitable for time series data as it produces both long-run relationships and short-run dynamics simultaneously. Our results show that FDI inflows have a positive and statistically significant influence on economic growth in the long run. Similarly, in the long run, both human capital and trade openness have also improved the long-run growth of Saudi Arabia. Furthermore, a positive and statistically significant influence of natural resources on economic growth is observed in the long run. Moreover, the results show that total factor productivity and domestic investment have not had the desirable influences on economic growth. The short-run results show that the growth performance of Saudi Arabia could be explained by natural resources, domestic investment and human capital. The causality analysis also confirmed a one-way relationship running from FDI inflows towards economic growth. Our results have a significant policy implication for the policymakers of Saudi Arabia. Full article

Background: Head and neck squamous cell carcinoma (HNSCC) remains a highly aggressive malignancy with poor clinical outcomes. Although poly(ADP-ribose) polymerase (PARP) inhibitors have shown promising activity in tumors with homologous recombination deficiency, their efficacy in BRCA wild-type HNSCC remains limited. Reactive oxygen species (ROS)-induced DNA damage may increase cellular dependence on DNA repair pathways and thereby enhance sensitivity to PARP inhibition. This study investigated whether ROS-mediated DNA damage could sensitize BRCA wild-type HNSCC cells to the PARP inhibitor olaparib. Methods: BRCA wild-type HSC-3 and SCC-25 HNSCC cell lines were exposed to H₂O₂ to induce oxidative stress. Intracellular ROS levels were quantified using DCFDA assays, DNA double-strand breaks were evaluated by γ-H2AX ELISA, PARP activity was assessed by ELISA, and cell viability was determined using MTT assays. Expression levels of DNA repair genes (PARP1, PARP2, BRCA1, BRCA2, RAD51, and MLH1), checkpoint kinases (ATM, ATR, and CHK1), the homologous recombination regulator FANCD2, and redox defense genes (NQO1, GPX4, and SLC7A11) were analyzed by qRT-PCR. Therapeutic selectivity was assessed using HGF-1 normal human gingival fibroblasts as a normal cell control. Apoptosis was measured through caspase-3/7 activity assays, and drug interactions were evaluated using the Chou–Talalay method. Results: H₂O₂ treatment increased intracellular ROS levels in both cell lines, accompanied by significant induction of DNA damage as demonstrated by elevated γ-H2AX levels. ROS induction markedly enhanced olaparib sensitivity, significantly reducing IC₅₀ values in both HSC-3 and SCC-25 cells. Combined H₂O₂ and olaparib treatment produced strong synergistic cytotoxicity, suppressed DNA repair, checkpoint kinase, and redox defense gene expression, and increased caspase-3/7 activity compared with control cells. Importantly, the combination demonstrated selective cytotoxicity toward cancer cells, with normal HGF-1 cells retaining significantly higher viability. Conclusions: ROS-induced DNA damage significantly enhances the anti-tumor activity of olaparib in BRCA wild-type HNSCC cells through a functional synthetic lethal-like interaction involving the simultaneous collapse of DNA repair capacity, checkpoint activation, and oxidative stress buffering, culminating in apoptosis induction. These findings support the rationale for combining ROS-generating therapies with PARP inhibitors in HNSCC treatment. Full article

The rapid pace of urbanization, coupled with the variability in climatic conditions, has led to a marked increase in global food demand. Simultaneously, this phenomenon has resulted in a decline in the overall quality of food, highlighting the need to improve existing agricultural production systems. In this context, zeolite has emerged as a promising soil amendment for optimizing its physical properties and crop yields. However, there is limited information on its effects during tomato cultivation, particularly for the Saladette variety (Solanum lycopersicum L.) in Hidalgo, Mexico. This includes the use of this zeolite variety, the evaluation of its antioxidant properties, and its antioxidant activity at different applied concentrations. This study evaluated the effect of different concentrations of zeolite applied to the soil on tomato growth and fruit quality. After crop establishment, the treatments were monitored monthly. The results showed that the application of zeolite significantly improved crop yield, with Treatment 3 (5 kg zeolite plant⁻¹) showing the best performance without affecting the physical characteristics of the fruit. The tomatoes maintained adequate commercial standards, with weights ranging from 104 a 169 g, sizes from 5.16 to 6.20 cm, and firmness values between 1.19 and 2.27 N; therefore, this treatment was selected for the determination of the antioxidant activity on the fruits. Furthermore, an increase in antioxidant capacity was observed, reaching 5.50 µmol TE/100 g of dry sample in the DPPH antioxidant capacity test. This demonstrates that zeolite application positively influences the quality and antioxidant capacity of tomatoes. This suggests that zeolite could be used in various crops, potentially improving the quality of the final product and offering health benefits to consumers thanks to the antioxidant compounds generated during harvest. However, further studies are needed to determine the optimal application rates and the long-term effects on soil health and crop productivity. Full article

To establish a comprehensive quality control method for Qili Qiangxin Capsules, an HPLC-DAD-ESI-MS/MS approach was developed for characteristic chromatogram analysis, marker compound identification, and multi-compound quantification. Similarity analysis of the characteristic chromatogram was conducted, and 25 characteristic peaks were identified using MS/MS fragment information. Methodological validation (specificity, linearity, precision, stability, repeatability, spiked recovery) was performed, followed by content determination of the 25 marker compounds. Results showed that the similarity of 10 batches of samples was >0.9 (Peak 6 as reference peak). The methodological validation for the quantitative analysis of 25 compounds met the requirements. All 25 compounds exhibited good linearity (R² > 0.999), with spiked recoveries of 98–103% (RSD < 2.0%). All validation indicators met Chinese Pharmacopoeia requirements. The established method is specific, precise, and stable, enabling simultaneous characteristic chromatogram identification and multi-compound quantification of Qili Qiangxin Capsules. It provides technical support for production quality supervision and clinical medication safety, and offers a reference for quality control of similar traditional Chinese medicine preparations. Full article

The concurrent circulation of influenza A virus (IAV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has unveiled complex host–pathogen interactions governed by temporal dynamics of innate immune activation. This narrative review synthesizes evidence from human air–liquid interface (ALI) epithelial models, animal studies (hamster, ferret), clinical cohorts, and randomized controlled trials (2015–2026) to delineate the molecular mechanisms underlying viral interference between these two major respiratory pathogens. Prior IAV infection induces a robust type I/III interferon (IFN) response and broad interferon-stimulated gene (ISG) upregulation that restricts subsequent SARS-CoV-2 replication within a critical 24–72 h temporal window. Conversely, SARS-CoV-2 employs a multi-layered immune evasion strategy that blunts IFN induction, providing minimal heterologous protection. Simultaneous co-infection tends to exacerbate disease severity. Host genetic determinants, including OAS1 and TLR7 variants, modulate interference capacity. Therapeutically, early pegylated IFN-λ shows clinical benefit, while experimental evidence from in vitro and animal models suggests oseltamivir may paradoxically reduce IAV-induced interference. These findings underscore the need for multi-pathogen diagnostics, temporally informed clinical decision-making, and IFN-based therapeutic strategies during co-circulation periods. Full article

This exploratory study examines the heterogeneous spatial evolution of cities in a fragmented non-metropolitan region of Southern Brazil and develops an original functional-symbolic typological framework that integrates functional performance and symbolic production in the classification of cities. Grounded in the theoretical contributions of Lefebvre, Santos, and Corrêa, the framework was designed by the authors to simultaneously incorporate economic, territorial, cultural, and identity-related dimensions that are typically analysed separately in conventional urban typologies. The research adopts a qualitative and inductive approach to analyse secondary data from municipalities in the state of Santa Catarina. Rather than treating urbanisation as a homogeneous process, the study conceptualises urban typologies as analytical devices capable of revealing differentiated urban trajectories, uneven capacities of territorial articulation, and distinct modes of governance in non-metropolitan contexts. The findings show that cities with similar demographic scales perform diverse social, cultural, and economic roles shaped by historically and symbolically produced spatial relations. Five urban typologies were identified: Multifunctional Metropolises, Industrial Regional Capitals, Agroindustrial Cities, Cultural Tourist Cities, and Local Centres of Basic Function. The results demonstrate that urban centrality in non-metropolitan regions is not determined solely by economic performance or demographic scale, but also by symbolic attributes such as cultural heritage, territorial identities, festivals, and religious functions. By integrating material and symbolic dimensions within a single analytical structure, the proposed framework advances the understanding of fragmented urban systems, contributes to contemporary debates on non-metropolitan urbanisation and territorial governance, and offers a transferable approach for the analysis of urban diversity beyond the Brazilian context. The findings also provide practical implications for regional planning and public policy by highlighting the role of symbolic production in shaping territorial organisation and regional influence. Full article

Supportive therapy with haemoadsorption is gaining popularity in critically ill patients, with the aim of reducing overinflammation triggered by the cytokine storm. The haemoadsorbers used are not specific for cytokines and also bind antibiotics. The aim of this study was to develop and validate a simple analytical method for the simultaneous determination of selected antibiotics and to develop an in vitro model for the quantification of their binding to the CytoSorb^® haemoadsorber under conditions simulating sepsis. Imipenem (IMI), amoxicillin (AMO), cefepime (CEF), meropenem (MERO), vancomycin (VAN) and piperacillin (PIP) were measured in bovine plasma via precipitation with acetonitrile and liquid–liquid extraction with dichloromethane. The aqueous phase was collected and analysed using a C18 HPLC system under gradient conditions, with modulation of organic solvent content and mobile phase pH, and detection performed using a UV/Vis detector. The method was linear (r² > 0.982) across investigated analytical ranges (1.0–100.0 µg/mL for AMO and VAN, 1.0–75.0 µg/mL for CEF, MERO and PIP and 2.5–100.0 µg/mL for IMI). Intra- and inter-day precision did not exceed 14% and accuracy ranged from 85.8% to 108.5%. Using the in vitro model, we showed that CytoSorb^® significantly removed VAN and PIP, but not MERO. Further clinical studies are needed to establish the clinical significance of these findings and their impact on antibiotic exposure. Full article

Spaceborne spectrometers are key optical payloads for global and regional greenhouse gas (GHGs) monitoring. With the increasing demands for high-precision and high-efficiency monitoring, spectrometers are required to provide a wide swath, high spatial resolution, and high spectral resolution. However, existing spaceborne grating spectrometers still face a trade-off between swath width and spatial resolution. To address this issue, this paper presents the optical design and fabrication of an immersed-grating spectrometer for GHG monitoring. The proposed spectrometer achieves a swath width of 100 km and a spatial resolution of 3 km × 3 km while providing high spectral resolution. It operates in four channels centered at 0.76, 1.61, 2.06, and 2.30 μm, covering the O₂-A band and the main absorption bands of CO₂ and CH₄, with corresponding spectral resolutions of 0.04, 0.07, 0.09, and 0.10 nm, respectively. The four channels share a common slit, which reduces system volume and inter-channel spatial registration errors. Immersed gratings are used as the core dispersive elements, enabling high spectral resolution in a compact optical configuration. To correct the smile and anamorphic beam compression induced by high-angular-dispersion immersed gratings, a prism-based simultaneous correction method is proposed. Based on this method, the initial parameters of the dispersion module are determined, and the optical design of the spectrometer is completed. Large-sized immersed gratings with high groove density are precisely fabricated using holographic lithography and ion-beam etching, after which the spectrometer is aligned and tested. The test MTF at the Nyquist frequency of the spatial dimension exceeds 0.72, indicating good imaging quality. The test spectral resolution of the four channels is all better than the design value, and the maximum smile and trapezoidal distortion are both within one pixel. This spectrometer provides an effective technical solution for achieving wide-swath, high-spatial-resolution, and high-spectral-resolution GHG monitoring under constraints imposed by detector size, signal-to-noise ratio, and payload size and mass. Full article

In smart grid operation, the scarcity of abnormal samples causes data imbalance, which is a key factor limiting the accuracy of anomaly detection. To address this issue and simultaneously solve the problem of easily losing weak abnormal signals in one-dimensional time-series data, an abnormal data detection method for grid information using an improved AlexNet considering sample imbalance is proposed. Firstly, features like voltage, current, and power are extracted from historical data. Missing values are filled via Lagrange interpolation, and abnormal boundaries are determined using box plots to construct high-quality samples. Secondly, to address the problem of few abnormal samples and imbalanced distribution, an enhanced learning strategy combining time-series translation and Gaussian noise injection is adopted to expand the abnormal samples and obtain sufficient training data. Then, to preserve the integrity of weak signals in one-dimensional time-series data and amplify the differences in abnormal features, the Gram angle field is used to convert multi-dimensional time-series data into a two-dimensional image, achieving the visual representation of time-series features. Finally, combined with the powerful image detection capability of AlexNet, it is improved by lightweighting the network structure, introducing the multi-head self-attention mechanism, and optimizing the training strategy to adapt to abnormal detection in the small sample and imbalanced environment of the grid. The simulation experiments show that the proposed method achieves an accuracy rate of 91.32% on extremely imbalanced datasets, which is at least 3.1% higher than those of other models. Full article

As a key component of space telescopes, the rational structure of the mirror is a crucial factor affecting the telescope’s environmental adaptability and imaging performance. To address the technical challenges of simultaneously achieving lightweight, environmental adaptability, and surface accuracy in large-aperture ultrathin mirrors, this paper proposes a mirror optimization method based on multiphysics coupling. Based on the finite element method and thermoelasticity theory, the interaction relationship between the temperature physical field and the force physical field was established. The P-norm was used to solve the problems of non-smoothness and inability to solve the sensitivity of the $\max (·)$ function. An optimized model for the mirror was determined using a combination of topology optimization and parameter optimization. Compared to a solid mirror, the optimized mirror achieved a mass reduction rate of 82.04%. Under temperature and gravity conditions, the surface accuracy of the optimized mirror met the requirements. In terms of response dynamics, the optimized mirror performs better, with a maximum response amplification factor of 4.39, below the threshold of 4.5 required to maintain structural stability, which is crucial for maintaining the structural integrity of the mirror. This method will provide a feasible approach for the optimized design of lightweight mirrors with strong environmental adaptability. Full article

Background: We present a miniature (30 × 34 mm) 64-channel data acquisition headstage optimized for high-density surface electromyography. Methods: The headstage is made up of a multi-channel ASIC analogue front-end utilizing only MOS transistors, fabricated in 350 nm CMOS technology (IC die dimensions 6.9 × 1.8 mm), combined with an off-the-shelf multi-channel current-input ADC (DDC264, Texas Instruments). The ASIC analogue front-end employs MOS-based capacitors for both processing and AC-coupling. Results: The combination of these two sub-circuits enables the simultaneous recording of 64 channels at a typical sampling rate of 4 KHz with a maximum analogue bandwidth of 0.5–1500 Hz and a resolution of 20-bits. Typical input-referred-noise, determined by the analogue front-end, is 3.5 μV_RMS for a surface EMG bandwidth of interest of 20–500 Hz. This two-chip solution results in a power consumption of 5 mW per channel. Analogue performance variability of the custom ASIC was characterized across a dataset of 960-channels (15 dies) from two fabrication runs. Conclusions: This work practically demonstrates the viability of using both a MOS-only analogue front-end and commercially available off-shelf high-performance back-end hardware already developed for medical imaging applications to record high-density surface biosignals. The aforementioned techniques can be employed to reduce the size and cost for systems or wearable devices; facilitating the translation of high-density bio-acquisition setups from the research environment to more affordable commercial products. Full article

The central charge occupies a unique role in conformal field theory, simultaneously serving as a measure of degrees of freedom, as the determinant of Casimir energy through modular transformations, and as an obstruction to the naive extension of the Witt algebra. The Virasoro central extension itself is rigid: it fixes c as a label of a given conformal field theory. In this work, we propose that higher categorical coherence—the pentagon and hexagon constraints governing fusion and braiding data, one level above the cocycle responsible for the Virasoro extension—supplies an additional, physically controllable handle. We show that controlled deformations of this higher coherence (higher categorical coherence breakdown, HCCB), implemented consistently through anomaly inflow, shift the effective central charge read out by anomaly-sensitive observables in quantized steps, opening the possibility of treating the measured central charge not as a fixed label but as an experimentally addressable piecewise-quantized quantity. We then focus on the fractional quantum Hall effect (FQHE), where the chiral central charge $c_{-}$ directly governs the quantized thermal Hall conductance. After reviewing the role of edge conformal field theories and current bounds on thermal transport, we propose experimental modifications—such as engineering multi-component edge states, coupling to non-Abelian quasiparticles, or introducing controlled categorical perturbations—that could render higher coherence breakdown detectable as shifts in the effective central charge. Two further elements complete the program. First, we show that within the consistent framework, all route- and bracketing-dependent observables vanish identically (route blindness), so that the pentagon and hexagon interferometers and thermal Y-junction networks we design operate as precision null tests of the modular-functor axioms themselves—the axioms stating that anyonic amplitudes are determined by the topology of a process rather than by the bookkeeping route used to compose it. Second, we show that a quantized remnant of route sensitivity survives in exactly one consistent form: the holonomy of closed cycles of categorical controls, realizing a central-charge pump for which the integer count per cycle is a family invariant beyond any static stacking description. The resulting framework provides both a conceptual reinterpretation of the central charge as a higher obstruction in categorical terms and a concrete experimental route for probing its dynamical behavior. Beyond the quantum Hall setting, these ideas suggest a broader program: anomalies, topological phases, and even string worldsheet central charges may admit reinterpretation through higher coherence. We conclude by outlining a research agenda in which categorical methods yield new experimental observables, potentially transforming the interplay between mathematics, condensed matter physics, and high-energy theory. Full article

This paper investigates the dynamical behavior of a three-species commensalism–amensalism system with Beddington–DeAngelis functional response. The model describes a novel tripartite interaction: a neutral–commensal species (e.g., sea anemone) simultaneously engages in a commensal relationship with a commensal–amensal species (e.g., clownfish) and an indirect nutritional coupling with a neutral–amensal species (e.g., crustacean), while the commensal–amensal and neutral–amensal species interact amensalistically. This paper makes three principal contributions. First, by constructing a Volterra-type Lyapunov function, we rigorously prove the global asymptotic stability of the unique positive equilibrium of the $(x,z)$-subsystem in the positive quadrant, and further establish the global asymptotic stability of both the amensal-free equilibrium $E_3$ and the coexistence equilibrium $E_4$ in the positive octant. Second, selecting the commensal benefit coefficient c as the bifurcation parameter, we present a complete and rigorous proof of a transcritical bifurcation. Third, we provide systematic Maple-based numerical verification: the bifurcation diagram exhibits excellent agreement with the theoretical curve, and logarithmic-scale plots confirm exponential convergence rates. Ecologically, our results reveal a sharp threshold phenomenon: when the commensal benefit coefficient lies below a critical value $c^{*}$, the commensal species inevitably goes extinct and the system collapses to a two-species state; when c exceeds $c^{*}$, the commensal species can invade and achieve stable three-species coexistence. The explicit formula for this threshold provides a quantitative criterion for determining the minimum mutualistic strength required for persistence in conservation contexts. The results obtained in this paper substantially extend the existing theoretical understanding of three-species commensalism–amensalism systems. Full article