Search Results (1,203)

Photoacoustic spectroscopy (PAS), quartz-enhanced photoacoustic spectroscopy (QEPAS), and light-induced thermoelastic spectroscopy (LITES) represent indirect absorption spectroscopy techniques for trace gas sensing, whose performance has long been advanced through hardware-oriented enhancement strategies. However, as hardware technologies continue to advance, conventional hardware-based enhancements are increasingly bottlenecked by weak responses, complex cross-interferences, and coupled multiphysics parameters. To transcend these limitations, algorithm-assisted methods, including traditional algorithms, machine learning, deep learning, and intelligent optimization, are being systematically integrated into these spectroscopic systems. This review summarizes recent progress in intelligent indirect absorption spectroscopy from three interconnected dimensions. First, we outline advanced signal processing and spectral reconstruction strategies designed to achieve weak-signal recovery and background noise suppression. Second, the focus shifts to data-driven parameter inversion, showing how multidimensional artificial intelligence models contribute to concentration retrieval, environmental compensation, multicomponent recognition, spectral-overlap decoupling, and front–back-end collaborative waveform coding and demultiplexing. Third, intelligent system optimization is examined, in which surrogate modeling, swarm-intelligence search, physics-guided topology optimization and multi-objective algorithms are employed to improve the design efficiency of the key elements such as photoacoustic resonators and multipass cells (MPCs). Additionally, prospects for future technological developments are also discussed in the concluding section. Full article

An important module that must be present in any communication system is a random number generator (RNG). One of the RNGs is the True RNG (TRNG), which is completely random. The output of the TRNG is unpredictable as it extracts its randomness from physical phenomena such as temperature, noise, power supply fluctuations, timing jitter in oscillators, and metastability in digital circuits. It is used in many applications such as cryptography, IoT sensors, and mobile equipment. In this paper, a novel low-power TRNG architecture is proposed: its core novelty is that all the system modules are adaptive to be more efficient and cooperate with system variations. It consists of a morphing gated ring oscillator, a lightweight real-time entropy monitoring, and a dynamic sampling window. Each module is verified before system integration. Our system strikes a favorable trade-off between randomness and power consumption as all the modules are implemented using LOMOS standard cells—a power-efficient topology for CMOS logic gate design. It consumes 0.226 μW from a 0.4 V supply at 1 MHz. The proposed architecture is evaluated using the NIST SP 800-22 statistical test suite, and successfully passes 10 randomness tests. Full article

Chronic hepatitis B virus (HBV) infection remains one of the main causes of hepatocellular carcinoma (HCC), even though vaccination and long-term viral suppression have reduced new infections and circulating viral replication. This residual cancer risk suggests that serum HBV DNA alone does not capture the full biology of HBV-related carcinogenesis. Hepatitis B virus X protein (HBx) is a relevant entry point because it maintains the transcriptional competence of covalently closed circular DNA (cccDNA), engages host chromatin regulators, and may persist in tumors as cccDNA-derived, integration-derived, full-length, truncated, or fusion forms. This review focuses on a specific question: does the available literature support HBx-associated reactivation of the IGF2 locus in chronic HBV infection and HBV-related hepatocarcinogenesis, and, if so, at which regulatory layer is the claim defensible? The most direct evidence remains promoter-proximal. Classic mechanistic work shows acute HBx-dependent activation of IGF2 promoter P4 through Sp1- and PKC/ERK-dependent signaling. Human tissue and cell-based studies also support a broader fetal-promoter compartment, including P3/P4 transcript enrichment, local promoter hypomethylation, MBD2-HBx-CBP/p300 recruitment, and increased histone H3/H4 acetylation. These observations do not, however, establish HBV exclusivity, uniform loss of imprinting, or direct HBx-mediated rewiring of the human IGF2/H19 topological domain. Recent integration-aware and long-read studies further argue against treating tumor-stage HBx as a single biological variable. In the present evidence framework, HBx-associated IGF2 locus reactivation is therefore more appropriately viewed as a stage-aware, promoter-resolved, biomarker-oriented hypothesis than as a universal mechanism or a treatment algorithm for HBV-related HCC. Full article

While minimalist kinetic models effectively capture the acute inverse coupling between Hepatitis B (HBV) and Hepatitis Delta (HDV), they often fail to account for the asymptotic stability and long-term viral plateaus observed during clinical therapy. In this work, we present an expanded compartmental framework integrating the non-linear dynamics of susceptible (S) and infected (I) hepatocyte populations, explicitly incorporating the satellite nature of HDV. Using the next-generation matrix method and Lyapunov stability theory, we analytically derive R₀ and prove the global attractivity of the endemic equilibrium. We demonstrate that “Target Cell Limitation” serves as the fundamental homeostatic governor. A transcritical bifurcation at threshold drug efficacy ε ≈ 0.9 marks the mathematical boundary between chronic persistence and viral extinction. Full article

Rising demand for high-performance battery thermal management systems (BTMSs) has rendered single-mode cooling insufficient for advanced lithium-ion batteries (LIBs) in new energy vehicles (NEVs), particularly under high discharge rates. This study proposes a synergistic hybrid BTMS integrating composite phase-change material (CPCM)–aluminum foam with liquid cooling to enhance thermal regulation of cylindrical battery modules under 5 C discharge conditions. Multiple liquid-cooled plate (LCP) configurations, including serpentine, straight, and leaf-shaped designs, together with different flow channel topologies (FCTs), were systematically investigated and optimized. The effects of coolant flow speed (CFS) and ambient temperature were also analyzed. Results indicate that the optimized leaf-shaped LCP with FCT #2 delivers superior performance, limiting the maximum temperature to 309.98 K, reducing temperature difference by 7.6%, and decreasing pressure drop by 88.79% compared to the serpentine configuration. Increasing CFS improves heat dissipation and delays PCM melting, although it raises pressure losses. Furthermore, the proposed system maintains a cell-to-cell temperature difference below 0.51 K, indicating excellent thermal uniformity. Compared to a CPCM-only system, the hybrid BTMS reduces peak temperature by 8.81 K under elevated ambient conditions (309.15 K), demonstrating strong potential for reliable and efficient thermal management in demanding operating environments. Full article

Reliable battery health assessment is essential to accelerate battery electric vehicle (BEV) adoption, yet most existing in-vehicle methods do not capture the complex processes driving ageing. Electrochemical impedance spectroscopy (EIS) offers deeper diagnostic insight but faces significant architectural and integration constraints. This study establishes a rigorous system-level framework for practicable onboard EIS implementation, focusing on the integration within Battery Management System (BMS) and powertrain architectures. Various integration topologies for cell-, module- and pack-level EIS are evaluated, highlighting their key trade-offs. The viability of the presented architectures is assessed through an application-specific Multi-Criteria Decision Analysis (MCDA) for mass-market, high-performance and circular economy use-cases. This study confirms the feasibility of onboard EIS while providing industry and scientific stakeholders with practical guidance to advance battery diagnostics for next-generation BEVs. Full article

Phosphoric acid-doped polybenzimidazole membranes are a leading fluorine-free electrolyte platform for high-temperature proton exchange membrane fuel cells, enabling proton transport under anhydrous conditions. However, recent evidence shows that conductivity, mechanical stability, and acid retention are intrinsically coupled, preventing independent optimization of these properties. This review establishes a unified framework in which membrane performance is governed by a multidimensional design space defined by acid doping level, activation energy (E_a), hydrogen-bond network topology, and mechanical confinement. Conductivity is shown to scale with both carrier density and hopping energetics, while mechanical stability decays with increasing ADL due to acid-induced plasticization, described through a semi-empirical relationship. Analysis across molecular architectures, including molecular weight control, crosslinking, backbone modification, topological design, and free-volume engineering, demonstrates that performance emerges from a balance between transport efficiency and structural stability. Device-level benchmarking further reveals that similar conductivity values can correspond to orders-of-magnitude differences in voltage decay rate, confirming that durability is governed primarily by mechanical confinement and acid mobility rather than σ alone. A multivariate stability corridor is identified, within which phosphoric acid-doped polybenzimidazole membranes achieve σ ≈ 0.14–0.20 S·cm⁻¹ while maintaining low degradation rates under realistic high temperature proton exchange membrane conditions. Based on this framework, quantitative design rules are derived linking acid doping level, activation, topology, and mechanical properties. This work shifts membrane design from conductivity-driven optimization toward predictive structure–property–durability engineering, providing a basis for the development of next-generation HT-PEM fuel cells with sustained long-term performance. Full article

To address the insufficient voltage boost capability and excessive device stress of DC–DC converters at hydrogen fuel cell output ports—issues that hinder the safe and stable operation of megawatt-level grid-connected systems—this paper proposes a two-stage, multi-unit interconnected grid-connection topology. This topology features a single-switch boost capability with a double Z-source network, accompanied by a dedicated grid-connection control strategy. First, the switching device in the quasi-Z-source converter is positioned at the front end to mitigate the device stress in the DC boost stage of the grid-connected topology. Second, the inductors in the Z-source converter are replaced with quasi-Z-source networks to form a double Z-source structure, thereby enhancing the boost capability of the front-end DC–DC Boost converter for hydrogen fuel cells, reducing the duty cycle, and suppressing inductor ripple current. Subsequently, an AC/DC grid-connection regulation strategy is designed to achieve stable power output from the hydrogen fuel cells. The results show that compared with the traditional Z-source Boost converter scheme, the proposed topology increases the output voltage by 21.2% and reduces the voltage stress of the switching device by 8.3% at the rated output power, making it highly suitable for high-power applications. Finally, the correctness of the theoretical analysis and the effectiveness of the proposed topology are verified through simulations and experiments. Full article

Epithelial ovarian cancer (EOC) remains one of the most aggressive gynecological malignancies, largely due to late-stage diagnosis, therapeutic resistance, and molecular heterogeneity. This study aimed to identify biologically relevant hub genes and evaluate potential dual-target compounds against Cyclin-Dependent Kinase 1 (CDK1) and DNA Topoisomerase II Alpha (TOP2A) through an integrated computational framework. Transcriptomic datasets from GSE28799, GSE54388, and GSE14407 were analyzed to identify overlapping differentially expressed genes, followed by protein–protein interaction analysis, functional enrichment, survival assessment, molecular docking, ADMET profiling, and molecular dynamics simulations. Mechanistically, CDK1 and TOP2A participate in coordinated cell-cycle regulation associated with G2/M progression and chromosomal dynamics in ovarian cancer. Among the identified hub genes, CDK1 and TOP2A demonstrated marked overexpression and central topological importance within the interaction network. Functional enrichment analyses highlighted significant associations with mitotic cell-cycle regulation, DNA replication, and proliferative signaling pathways. Molecular docking analyses identified Naringin as a potential dual-target candidate with favorable binding affinity toward both CDK1 and TOP2A. ADMET profiling suggested acceptable pharmacokinetic and toxicity characteristics, while molecular dynamics simulations supported stable protein–ligand interactions under dynamic conditions. Although survival analyses did not demonstrate statistically significant independent prognostic associations, the findings support the biological relevance of CDK1 and TOP2A in EOC progression. Collectively, this study provides an integrated computational perspective on CDK1/TOP2A-associated oncogenic signaling and prioritizes Naringin as a preliminary candidate for future experimental investigation in epithelial ovarian cancer. Full article

Existing ground-slotted coplanar waveguide (CPW) spoof surface plasmon polariton (SSPP) low-pass filters (LPFs) remain constrained by the difficulty of achieving a wide stopband while maintaining a compact size, as well as by undesired radiation leakage arising from their open-aperture slot configuration. To address these issues, a grounded coplanar waveguide spoof surface plasmon polariton (GCPW-SSPP) low-pass filter based on a multi-arm star-shaped slot (MASS) loading topology is proposed. An equivalent-circuit interpretation and full-wave dispersion analysis show that the multi-arm slots introduce enhanced distributed reactive loading, thereby lowering the asymptotic frequency and enabling compact SSPP implementations. The near-field characteristics further demonstrate tighter electromagnetic confinement, as reflected by an approximately 48% reduction in the electric-field confinement width along the z-direction. To alleviate the trade-off between miniaturization and wide-stopband performance in cascaded SSPP LPFs, the single-cell S-parameters of the proposed topology are investigated. A single MASS unit exhibits a sharp cutoff and a deep transmission notch, allowing a wide stopband to be obtained with fewer cascaded cells. Radiation characteristics are subsequently quantified by a loss-decomposition method, and the MASS topology is found to suppress the radiation leakage of open-aperture ground-slotted structures, yielding a maximum radiation-loss reduction of approximately 75%. To validate the design methodology, a MASS-loaded GCPW-SSPP LPF is designed, fabricated, and measured. The measured results are in good agreement with the simulated ones, confirming the effectiveness of the proposed scheme. By simultaneously achieving a wide stopband, compact size, and suppressed radiation leakage, the proposed filter offers a promising low-interference filtering solution for highly integrated microwave and RF front-end systems. Full article

With the increasing penetration of renewable energy systems, multilevel inverters have been widely adopted to meet the growing demand for high-power and high-quality energy conversion. Among various multilevel topologies, cascaded H-bridge multilevel inverters (CHMIs) are particularly attractive due to their modular structure and improved output voltage quality. However, the increased number of power semiconductor devices and switching states significantly complicates fault diagnosis under practical operating conditions. Currently, most existing neural networks for fault diagnosis are manually designed based on domain expertise. This may limit their adaptability to task-specific fault patterns as well as edge-side inference performance. To reduce the dependence on manually designed diagnostic networks, an edge-oriented fault diagnosis framework based on differentiable architecture search (DARTS) is proposed to automatically design task-specific diagnostic networks. A simplified special cell search strategy is adopted to improve search efficiency and facilitate practical deployment. The searched architectures are lightweight and suitable for deployment on edge platforms. The experiments show that the proposed method achieves an average diagnostic accuracy of 99.44% on the test set under the RL load of $(7\mathrm{\Omega },6\mathrm{mH})$. Furthermore, the searched model contains only 0.2417 M trainable parameters, and edge deployment experiments on the Jetson Orin Nano platform show low-latency inference capability. Full article

Lightweight thin-walled energy-absorbing structures play a critical role in passive safety systems for automotive and aerospace engineering applications, yet simultaneously achieving high specific energy absorption and stable crushing behavior remains a persistent challenge. Inspired by the topology of natural honeycombs, this study proposes a novel modular assembled multi-cell carbon fiber reinforced polymer (CFRP) structure (MAMCS), fabricated via a cost-effective modular assembly strategy based on a wrapping process. Quasi-static axial crushing experiments combined with validated finite element simulations were employed to systematically investigate the effects of inner layup configurations ([0°/90°], [30°/−60°], [45°/−45°]), cell number, and inner sub-cell size on crushing behavior. Among the investigated layup configurations, the [0°/90°] inner layup exhibited superior mean crushing force (MCF) and specific energy absorption (SEA). Multi-cell architectures significantly enhanced load-bearing capacity and crushing stability through mechanical interactions among internal sub-cells. Parametric analyses further revealed that enlarging the inner sub-cell size elevates both MCF and SEA, although at the expense of a higher peak crushing force (PCF). A TOPSIS-based multi-criteria decision-making framework was applied to identify a preferred configuration that achieves a favorable balance between peak load mitigation and energy absorption efficiency. The proposed MAMCS, characterized by its simple modular assembly, cost-effective fabrication, and superior crashworthiness performance, offers a promising bio-inspired design strategy for developing high-performance lightweight energy-absorbing structures in axial impact applications. Full article

Addressing the challenge of power supply stability caused by the intermittent nature of photovoltaic power generation in off-grid microgrids, this study uses a commercial park in Wuhan as a case study and optimizes the capacity configuration of a photovoltaic–storage–hydrogen fuel cell hybrid microgrid system based on HOMER Pro software. First, a topology of the off-grid microgrid is constructed, comprising photovoltaic (PV), lithium-ion batteries, hydrogen fuel cells, and a diesel generator as backup. The power output characteristics, efficiency curves, and life-cycle cost models of each component are accurately established. On this basis, two typical operation strategies, namely Load Following (LF) and Cycle Charging (CC), are proposed and compared. The influence of different strategies on the optimal capacity configuration and operational economics is systematically analyzed, and the Cycle Charging strategy is identified as the optimal operation strategy for this scenario. Subsequently, a multi-scenario capacity optimization design is further conducted based on the optimal operation strategy. The minimization of net present cost (NPC) is taken as the primary objective, while multiple evaluation indicators such as renewable fraction (RF), levelized cost of electricity (LCOE), energy storage cycle life degradation, and system redundancy rate are comprehensively considered. The results show that, while ensuring 100% power supply reliability, the proposed model reduces the net present cost (NPC) by approximately 14.4% compared with the conventional PV-storage scheme. The renewable fraction (RF) reaches 95.8%, while the reliance on lithium-ion battery capacity is significantly reduced (battery capacity configuration decreased by 24.3%). This effectively extends the energy storage lifespan and enhances the overall economic and environmental benefits. The results provide a theoretical basis and technical reference for the planning and design of off-grid microgrids with high penetration of renewable energy. Full article

Local pulmonary delivery offers a non-invasive application route for mRNA therapeutics with the potential for high bioavailability at the target-site of applications such as mucosal vaccination or the treatment of lung diseases. However, efficient delivery remains challenging due to major lung-specific barriers, particularly mucus. Herein, pH-responsive, amphiphilic xenopeptides comprising lipoamino fatty acids and oligoamino acids (OAAs) connected in distinct branched U-shape or bundle topologies were evaluated as mRNA polyplexes for delivery to A549 and Calu-3 lung cells under standard submerged or air–liquid interface (ALI) transfection conditions, and upon intratracheal application in BALB/c mice. Optionally, polyplexes were coated with negatively charged hyaluronic acid (HA) or colloidally stabilized with poly(ethylene glycol) (PEG). For U-shapes, hydrophobic modification of the OAA domain boosted their efficiency. Interestingly, best-performing formulations varied across transfection conditions. While the bundle topology showed the highest potential in submerged cell culture, U-shaped carriers were more efficient under ALI conditions. Polyplex surface modification with HA or PEG did not strongly alter in vitro transfections, whereas hydrophobized U-shape core polyplexes combined with surface modification enhanced their efficiency in vivo. Thus, the cationizable core and surface properties of mRNA nanoparticles require specific balancing in various lung cell models and lung. Full article

Tissue engineering is widely used in research for investigating cellular proliferation, behavior, and responses to various stimuli. However, the predictive value of preclinical studies using cell culture plates is limited by the inability to recapitulate the complexity of the physiological microenvironment. Synthetic three-dimensional (3D) scaffolds can be engineered to mimic the complex morphology of the extracellular matrix of native tissues and can serve as physiologically relevant platforms for preclinical studies. In this study, 3D electrospun scaffolds were characterized to aid in breast cancer research. Unlike previous studies that focused primarily on scaffold fabrication or cell viability, this work systematically evaluates how scaffold morphology influences breast epithelial and breast cancer cell behavior within three-dimensional microenvironments. Breast cancer cell lines and normal breast epithelial cells were seeded on scaffolds of different morphologies, on commercially available mesh scaffolds, and on standard tissue culture plates. Cells were treated with a fluorescent fructose mimic (ManCou-H) that targets the fructose-specific transporter GLUT5 to assess metabolic activity on different scaffolds. The study evaluated cell–cell and cell–matrix interactions through time-lapse experiments, cell metabolism, and variations in the expression of cytoskeletal protein (CK18) and GLUT5. Statistically relevant differences were observed between cells cultured on scaffolds and plates, and different scaffolds morphologies. Results from this study demonstrate that scaffold topology alone can significantly alter cellular phenotype and metabolic responses, highlighting the importance of scaffold selection in the development of predictive non-animal in vitro models and studies of the tumor microenvironment. Full article