Search Results (1,716)

This paper describes a composite control approach that improves the accuracy and dynamic performance of the control of a voice-coil-driven, two-dimensional fast steering mirror (FSM). Strong nonlinearity, perturbation of parameters, unmodeled dynamics and external disturbances typically compromise the performance of the FSM. The proposed controller combines a tracking differentiator (TD), linear extended state observer (LESO), and a double-integral global fast terminal-sliding mode control (DIGFTSMC). The TD corrects the reference command signal, and the LESO approximates and counteracts system disturbances. The sliding surface is then equipped with the double-integral operators and an improved adaptive reaching law (IARL) to enhance tracking accuracy, response speed and robustness. Prior to physical experiments, systematic numerical simulations were conducted for five control algorithms across four typical test scenarios, verifying the proposed controller’s feasibility and preliminary performance advantages. It is found through experimentation that the proposed controller lowers the time esterified by the step response adjustment by 81.0% and 48.4% more than the PID controller and the DIGFTSMC approach with no IARL, respectively, and the proposed controller enhances error control when tracking sinuoidal signals and multisinusoidal signals. Simulation results consistently align with experimental trends, confirming the proposed controller’s superior convergence speed, tracking precision, and disturbance rejection capability. Furthermore, it cuts the angular movement swing by an average of over 44% through dismissing needless vibration interruptions as compared to other sliding mode control techniques. Experimental results demonstrate that the proposed composite control approach significantly enhances the disturbance rejection, control accuracy, and dynamic tracking performance of the voice-coil-driven FSM system. Full article

Unmanned airships are highly sensitive to parametric uncertainty, persistent wind disturbances, and sensor noise, all of which compromise reliable path-following. Classical control schemes often suffer from chattering and fail to handle index discontinuities on closed-loop paths due to the lack of mechanisms and cannot simultaneously provide formal guarantees on state constraint satisfaction. We address these challenges by developing a unified, constraint-aware guidance and control framework for path-following in uncertain environments. The architecture integrates an extended state observer (ESO) to estimate and compensate lumped disturbances, a barrier Lyapunov function (BLF) to enforce state constraints on tracking errors, and a super-twisting terminal sliding-mode (ST-TSMC) control law to achieve finite-time convergence with continuous, low-chatter control inputs. A constructive Lyapunov-based synthesis is presented to derive the control law and to prove that all tracking errors remain within prescribed error bounds. At the guidance level, a nonlinear curvature-aware line-of-sight (CALOS) strategy with an index-increment mechanism mitigates jump phenomena at loop-closure and segment-transition points on closed yet discontinuous paths. The overall framework is evaluated against representative baseline methods under combined wind and parametric perturbations. Numerical results indicate improved path-following accuracy, smoother control signals, and strict enforcement of state constraints, yielding a disturbance-resilient path-following solution for the cruise of an unmanned airship. Full article

Exosomes are important mediators of host–parasite communication and contain diverse molecules that may support the survival of Clonorchis sinensis in the biliary tract. To explore their biochemical properties, exosomes isolated from excretory–secretory products of Korean C. sinensis isolates were characterized through integrated morphological, proteomic, and gene ontology analyses. The vesicles exhibited typical exosomal size ranges and marker profiles, and their protein components were enriched for cytoskeletal, metabolic, and vesicle-trafficking components relevant to epithelial signaling and immune modulation. Among these proteins, sphingomyelin phosphodiesterase acid-like 3A (SMPDL3A) was examined in detail to obtain molecular evidence suggesting its role in sphingolipid metabolism in the parasite. The C. sinensis SMPDL3A (Cs_SMPDL3A) shared the overall structure and core catalytic residues with mammalian homologs, SMPDL3A and sphingomyelin phosphodiesterase 1 (SMPD1), a finding consistent with the possibility that Cs_SMPDL3A may retain authentic sphingomyelinase activity. Although lacking the saponin B domain of SMPD1, Cs_SMPDL3A carries a C-terminal transmembrane segment that may facilitate sphingomyelin access by positioning the enzyme on lipid bilayers. Collectively, these findings suggest that Cs_SMPDL3A participates in host sphingomyelin turnover, potentially generating ceramide for uptake by SMPD1-lacking C. sinensis or contributing to ceramide-associated immune responses in the biliary tract, offering new insight into lipid-centered host–parasite interactions during clonorchiasis. Full article

To address the lack of inertia in full-power converter wind turbines and the inability of existing mechanical speed regulation technologies to achieve power smoothing without converters, this paper proposes a novel hybrid wind energy storage system integrating a Continuously Variable Transmission (CVT) and an electromechanical flywheel. This system establishes a cascaded topology featuring “CVT-based source-side speed regulation and electromechanical flywheel-based terminal power stabilization.” By utilizing the CVT for speed decoupling and introducing the flywheel via a planetary differential branch, the system retains physical inertia by eliminating large-capacity converters and overcomes the bottleneck of traditional mechanical transmissions, which struggle to balance constant frequency with stable power output. Simulation results demonstrate that the proposed system reduces the active power fluctuation range by 47.60% compared to the raw wind power capture. Moreover, the required capacity of the auxiliary motor is only about 15% of the rated power, reducing the reliance on power electronic converters by approximately 85% compared to full-power converter systems. Furthermore, during a grid voltage dip of 0.6 p.u., the system restricts rotor speed fluctuations to within 0.5%, significantly enhancing Low Voltage Ride-Through (LVRT) capability. Full article

The poly(A) tail on viral mRNAs plays an important role in gene expression, given the role of the 3′ mRNA tail in mRNA stability and translation. Viruses have developed several strategies to maintain the integrity of their poly(A) tails. These include attracting stabilizing proteins through elements in the 3′ untranslated regions of their mRNA, remodeling their poly(A) tails using terminal nucleotidyl transferases, and blocking deadenylase access to the terminal 3′ end of their poly(A) tails using protein–protein interactions or through triple helical RNA structures. Collectively, the presence of these multiple strategies illustrates the vital overall need for viruses to maintain and preserve their poly(A) tails, highlighting a potential avenue for broad-spectrum antiviral development. In addition, poly(A) tail preservation strategies used by viruses may also be applied to RNA vaccines and therapeutics. Full article

Lipid raft-associated gangliosides facilitate the early stages of SARS-CoV-2 entry by triggering the exposure of the receptor-binding domain (RBD) within the trimeric spike protein, which is initially sequestered. A broad range of in silico, cryoelectron microscopy and physicochemical approaches indicate that the RBD becomes accessible after a ganglioside-induced conformational rearrangement originating in the N-terminal domain (NTD) of one protomer and propagating to the neighboring RBD. We previously identified a triad of amino acids, Q134-F135-N137, as a strictly conserved element on the NTD. In the present review, we integrate a series of structural and experimental data revealing that this triad may act as a conformational transducer connected to a chain of residues that are capable of transmitting an internal conformational wave within the NTD. This wave is generated at the triad level after physical interactions with lipid raft gangliosides of the host cell membrane. It propagates inside the NTD and collides with the RBD of a neighboring protomer, triggering its unmasking. We also identify a chain of aromatic residues that are capable of controlling electron transfer through the NTD, leading us to hypothesize the existence of a dual conformational/quantum wave. In conclusion, the complete conservation of the Q134-F135-N137 triad despite six years of extensive NTD remodeling underscores its critical role in the viral life cycle. This triad represents a potential Achilles’ heel within the hyper-variable NTD, offering a stable target for therapeutic or vaccinal interventions to disrupt the conformational wave and prevent infection. These possibilities are discussed. Full article

Biomarker-based prevention is rapidly expanding, driven by advances in molecular diagnostics, genetic profiling, and commercial direct-to-consumer (DTC) testing. General practitioners (GPs) increasingly encounter biomarker results of uncertain relevance, often introduced outside the guideline frameworks. This creates new challenges in interpretation, communication, and equitable resource use in primary care. This narrative review synthesizes evidence from population-based studies, guideline frameworks, consensus statements, and communication research to evaluate the predictive value, limitations, and real-world implications of biomarkers in asymptomatic adults. Attention is given to polygenic risk scores, DTC genetic tests, neurodegenerative and cardiovascular biomarkers, and emerging multi-omics and aging markers. Several biomarkers, including high-sensitivity cardiac troponins, N-terminal pro–B-type natriuretic peptide, lipoprotein(a), coronary artery calcium scoring, and plasma p-tau species, showed robust predictive validity. However, many widely marketed biomarkers lack evidence of clinical utility, offer limited actionable benefits, or perform poorly in primary care populations. Unintended consequences, such as overdiagnosis, false positives, psychological distress, diagnostic cascades, and widening inequities, are well documented. Patients often misinterpret unvalidated biomarker results, whereas DTC testing amplifies demand without providing adequate counseling or follow-up. Only a minority of biomarkers currently meet the thresholds of analytical validity, clinical validity, and clinical utility required for preventive use in general practices. GPs play a critical role in contextualizing biomarker results, guiding shared decision-making, and mitigating potential harm. The responsible integration of biomarkers into preventive medicine requires clear communication, strong ethical safeguards, robust evidence, and system-level support for equitable, patient-centered care. Full article

Existing vehicle-mounted satellite terminals primarily rely on mechanical or purely analog electronically steered antennas. They lack protocol-level relay capability and usually provide only short-range hotspot connectivity. These limitations make it difficult for such systems to deliver stable, high-throughput satellite access for personal mobile devices in dynamic vehicular environments, especially in remote regions without terrestrial networks. This paper proposes an intelligent vehicle repeater for satellite networks (IVRSN) that builds a dedicated satellite–vehicle–device relay architecture. It enables reliable broadband connectivity for conventional mobile terminals without requiring specialized satellite hardware. The IVRSN consists of three key technical components. Firstly, a dual-mode relay coverage mechanism is designed to support energy-efficient in-vehicle access and extended out-of-vehicle coverage. Secondly, a DoA-assisted, attitude-compensated hybrid beamforming scheme is developed. It combines subspace-based direction estimation with inertial sensor measurements to maintain high-precision satellite pointing under vehicle dynamics. Finally, a bidirectional protocol conversion module is introduced to ensure compatibility between ground wireless protocols and satellite link-layer formats with integrity-checked data forwarding. Compared to existing solutions, the proposed IVRSN provides higher stability and broader device compatibility, making it a feasible solution for high-speed, high-quality communications in remote or disaster regions. Full article

Glucose-dependent insulinotropic polypeptide (GIP) was the first incretin hormone identified, best known for promoting glucose-stimulated insulin secretion. Increasing evidence has expanded its physiological relevance beyond glucose metabolism, revealing a significant role for GIP in the gut–bone axis. In vitro studies demonstrate that GIP inhibits osteoclast differentiation and activity while promoting osteoblastic bone formation. Findings from genetic animal models and human variant analyses further support the essential role of endogenous GIP signaling in maintaining bone mass and quality. Exogenous administration of GIP suppresses the bone-resorption marker C-terminal telopeptide of type I collagen (CTX) and increases the bone-formation marker procollagen type I N-terminal propeptide (P1NP) in healthy individuals, reflecting an acute shift toward reduced bone resorption and enhanced bone formation. Moreover, GIP confers protection against bone deterioration in multiple pathological conditions, including postmenopausal osteoporosis, inflammatory bone loss, obesity, and diabetes, etc., suggesting therapeutic potential beyond physiological contexts. Recent evidence also shows that GIP attenuates orthodontic tooth movement by limiting mechanically induced osteoclast activity, highlighting its broader skeletal actions. In this review, we summarize recent advances regarding the role of GIP in bone metabolism, integrating evidence from cellular studies, animal models and human investigations, and discuss future directions for GIP-based interventions. Full article

Wind-induced response poses a significant challenge to the stability of extra-large-span heavy steel box girders during synchronous lifting operations. This study adopted a method combining numerical simulation with on-site monitoring to investigate the aerodynamic characteristics the beam during the overall hoisting process of the Xiaotun Bridge. A high-fidelity finite element model was established using Midas NFX 2024 R1, and fluid–structure interaction (FSI) analysis was conducted, utilizing the RANS k-ε turbulence model to simulate stochastic wind fields. The results show that during the lifting stage from 3 m to 25 m, the maximum horizontal displacement of the steel box girder rapidly increases at wind angles of 90° and 60°, and the peak displacement is reached at 25 m. Under a strong breeze at a 90° wind angle and 25 m lifting height, the maximum lateral displacement was 42.88 mm based on FSI analysis, which is approximately 50% higher than the 28.58 mm obtained from linear static analysis. Subsequently, during the 25 m to 45 m lifting stage, the displacement gradually decreases and exhibits a linear correlation with lifting height. Concurrently, the maximum stress of the lifting lug of the steel box girder increases rapidly in the 3–25 m lifting stage, reaches the maximum at 25 m, and gradually stabilizes in the 25–45 m lifting stage. The lug stress under the same critical condition reached 190.80 MPa in FSI analysis, compared with 123.83 MPa in static analysis, highlighting a significant dynamic amplification. Furthermore, the detrimental coupling effect between mechanical vibrations from the lifting platform and wind loads was quantified; the anti-overturning stability coefficient was reduced by 10.48% under longitudinal vibration compared with lateral vibration, and a further reduction of up to 39.33% was caused by their synergy with wind excitation. Field monitoring validated the numerical model, with stress discrepancies below 9.7%. Based on these findings, a critical on-site wind speed threshold of 9.38 m/s was proposed, and integrated control methods were implemented to ensure construction safety. During on-site lifting, lifting lug stresses were monitored in real time, and if the predefined threshold was exceeded, contingency measures were immediately activated to ensure a controlled termination. Full article

Plastic streams dominated by polyethylene (PE) including PE HD/MD (High Density/Medium Density) and PE LD/LLD (Low Density/Linear Low Density), polypropylene (PP), and polyvinyl chloride (PVC) across Europe demand a design framework that links synthesis with end of life reactivity, supporting circular economic goals and European Union waste management targets. This work integrates polymerization derived chain architecture and depolymerization mechanisms to guide selective valorization of commercial plastic wastes in the European context. Catalytic topologies such as Bronsted or Lewis acidity, framework aluminum siting, micro and mesoporosity, initiators, and strategies for process termination are evaluated under relevant variables including temperature, heating rate, vapor residence time, and pressure as encountered in industrial practice throughout Europe. The analysis demonstrates that polymer chain architecture constrains reaction pathways and attainable product profiles, while additives, catalyst residues, and contaminants in real waste streams can shift radical populations and observed selectivity under otherwise similar operating windows. For example, strong Bronsted acidity and shape selective micropores favor the formation of C₂ to C₄ olefins and Benzene, Toluene, and Xylene (BTX) aromatics, while weaker acidity and hierarchical porosity help preserve chain length, resulting in paraffinic oils and waxes. Increasing mesopore content shortens contact times and limits undesired secondary cracking. The use of suitable initiators lowers the energy threshold and broadens processing options, whereas diffusion management and surface passivation help reduce catalyst deactivation. In the case of PVC, continuous hydrogen chloride removal and the use of basic or redox co catalysts or ionic liquids reduce the dehydrochlorination temperature and improve fraction purity. Staged dechlorination followed by subsequent residue cracking is essential to obtain high quality output and prevent the release of harmful by products within European Union approved processes. Framing process design as a sequence that connects chain architecture, degradation chemistry, and operating windows supports mechanistically informed selection of catalysts, severity, and residence time, while recognizing that reported selectivity varies strongly with reactor configuration and feed heterogeneity and that focused comparative studies are required to validate quantitative structure to selectivity links. In European post consumer sorting chains, PS and PC are frequently handled as separate fractions or appear in residues with distinct processing routes, therefore they are not included in the polymer set analyzed here. Polystyrene and polycarbonate are outside the scope of this review because they are commonly handled as separate fractions and are typically optimized toward different product slates than the gas, oil, and wax focused pathways emphasized here. Full article

Due to the neuroprotective and antioxidant properties, phenylethanoid glycosides (PhGs) are valuable plant-derived compounds. Traditional extraction methods are constrained by low yields and limited resources, prompting the integration of synthetic biology and enzyme engineering technologies for sustainable production. This review summarizes the advances in the microbial synthesis of PhGs, emphasizing the elucidation of biosynthetic pathways, enzyme engineering modifications of glycosyltransferases and acyltransferases, and strategies for optimizing microbial cell factories in Escherichia coli and Saccharomyces cerevisiae. Significant advancements encompass the efficient synthesis of verbascoside and echinacoside in S. cerevisiae, as well as the comprehensive elucidation of the echinacoside biosynthetic pathway in Cistanche spp., including the identification of key steps catalyzed by a rhamnosyltransferase, a CYP450 hydroxylase, and a terminal glucosyltransferase that enable pathway reconstruction in S. cerevisiae. We conduct a systematic analysis of methods to address the biosynthetic bottlenecks via protein engineering, including rational design and directed evolution, as well as the metabolic engineering strategies such as precursor enhancement and cofactor recycling. Additionally, we investigate the synthesis of non-natural PhG analogues and the prospective integration with AI-assisted design, emphasizing the significant potential of microbial systems in overcoming the supply challenges for medicine-food homologous ingredients. Full article

Background/Objectives: Osteoarthritis (OA) is a pervasive chronic joint disease characterized by the triad of persistent articular cartilage degeneration, debilitating synovial inflammation, and sustained chronic pain. Although salmon nasal cartilage proteoglycan (SPG) is recognized for supporting joint health, the precise molecular mechanism underlying its effects during OA progression remains to be fully elucidated. This study evaluated the therapeutic efficacy of SPG using a monosodium iodoacetate (MIA)-induced mouse model. Methods: A total of 180 male C57BL/6J mice (six-week-old) were utilized, organized into three independent cohorts to analyze distinct analytical endpoints: (1) pain assessment, histology, and immunohistochemistry; (2) mRNA expression analysis for early-stage OA (Day 3); and (3) mRNA expression analysis for the late-stage OA (Day 28). All subjects received daily oral treatment via gavage, commencing 5 days prior to OA induction and continuing until the designated experimental termination points (either Day 3 or Day 28). Each cohort comprised five experimental groups (n = 10–12 per group): a saline-injected Sham group, an MIA-induced Control group, a positive comparator receiving celecoxib (CLX, 20 mg/kg/day), and two groups administered SPG at a dose of 50 or 100 mg/kg/day. Results: Our findings demonstrated that SPG, particularly at the 100 mg/kg dose, significantly mitigated joint pain symptoms, performing comparably to CLX. Histopathological assessments confirmed that SPG effectively preserved the structural integrity of the cartilage matrix and substantially reduced pathological damage, as evidenced by lower Mankin scores. Mechanistically, SPG treatment led to a marked downregulation of degradative enzymes, including matrix metalloproteinase-3 (MMP-3) and a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4), while concurrently normalizing the levels of tissue inhibitors of metalloproteinases (TIMPs). Furthermore, SPG prevented the aberrant, over-compensatory expression of anabolic markers such as SRY-box transcription factor 9 (SOX-9), type II collagen alpha 1 chain (COL2A1), and aggrecan (ACAN) typically observed in the disease’s later stages. While SPG demonstrated a limited impact on broadly pro-inflammatory cytokine profiles, it specifically and significantly reduced interleukin-6 (IL-6) gene expression during the chronic phase. Conclusions: These results suggest that SPG serves as a promising natural agent that maintains articular homeostasis by balancing matrix metabolic pathways, positioning it as a scientifically validated functional food candidate for the management of joint health. Full article

Obesity-associated inflammation underlies much of cardiometabolic pathology, reflecting the convergence of chronic, low-grade systemic immune activation with region-specific maladaptation of adipose depots. Among these, epicardial adipose tissue (EAT)—a visceral fat layer contiguous with the myocardium and sharing its microvasculature—functions as a cardio-proximal immunometabolic interface that influences atrial fibrillation, heart failure with preserved ejection fraction, and coronary atherogenesis through paracrine crosstalk. These relationships extend beyond crude measures of adiposity, emphasizing the primacy of local inflammatory signaling, adipokine flux, and fibro-inflammatory remodeling at the EAT–myocardium interface. Of importance, substantial weight reduction only partially reverses obesity-imprinted transcriptional and epigenetic programs across subcutaneous, visceral, and epicardial depots, supporting the concept of an enduring adipose memory that sustains cardiovascular (CV) risk despite metabolic improvement. Accordingly, therapeutic strategies should move beyond weight-centric management toward mechanism-guided interventions. Resolution pharmacology—leveraging specialized pro-resolving mediators and their cognate G-protein-coupled receptors—offers a biologically plausible means to terminate inflammation and reprogram immune–stromal interactions within adipose and CV tissues. Although preclinical studies report favorable effects on vascular remodeling, myocardial injury, and arrhythmic vulnerability, clinical translation is constrained by pharmacokinetic liabilities of native mediators and by incomplete validation of biomarkers for target engagement. This review integrates mechanistic, depot-resolved, and therapeutic evidence to inform the design of next-generation anti-inflammatory strategies for obesity-related CV disease. Full article

Single-phase-to-ground faults occur frequently in distribution networks, while traditional localization methods have limitations such as insufficient feature extraction and poor topological adaptability. To address these issues, this paper proposes a two-stage localization method that integrates the Node Classification Matrix (NCM) and an Improved Binary Particle Swarm Optimization (IBPSO) algorithm. The NCM achieves rapid initial localization, and the IBPSO performs error correction. This paper employs an IEEE 33-node standard distribution network model to design simulations covering scenarios with varying fault locations, multiple fault resistances, and different numbers of node distortions for validation. The results demonstrate that the proposed method achieves a fault location accuracy of 96%, which is 19% higher than that of the NCM alone and 2% higher than that of the IBPSO alone. Moreover, it maintains an accuracy of over 95% under scenarios of 1–3 node distortions, topological switching, and high-impedance faults, and is compatible with existing Feeder Terminal Unit (FTU) devices. This method effectively balances localization speed and robustness, providing a reliable solution for the rapid fault isolation of distribution network. Full article