Search Results (6,051)

In this work, high-resolution sparse channel estimation in multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems is addressed. Firstly, a block-structured compressed channel sensing (CCS) model with high spectral efficiency and high delay resolution is constructed. Then, by fully exploiting the temporal correlation and joint sparsity of the channels, a novel two-stage prior delay support-aided delay tracking and block residual norm minimization (PDSA-DT-BRNM) algorithm is proposed. In the first stage, with a limited number of pilots for each antenna and the delay grids within the prior delay support, an efficient delay tracking and block norm minimization algorithm is put forward to choose the common delay grids and estimate each block gain iteratively. In the second stage, by comprehensively utilizing the intermediate channel estimation results of the first stage and the prior delay support, an optimized channel estimation strategy is developed based on the block residual norm minimization (BRNM) criterion. Simulation results and theoretical analysis show the effectiveness of the proposed channel estimation scheme in terms of channel estimation performance, spectral efficiency and computational complexity. Full article

The increasing complexity and extended operational lifetimes of modern space infrastructure have significantly intensified the demand for reliable structural health monitoring (SHM) systems. However, the extreme space environment, characterized by radiation exposure, microgravity, ultra-high vacuum, and severe thermal cycling, imposes critical limitations on conventional electrical sensing technologies, leading to reduced measurement accuracy, instability, and long-term degradation. This review presents a comprehensive analysis of fiber Bragg grating (FBG)-based sensing technologies as a promising solution for deformation monitoring in space infrastructure. The study investigates the fundamental operating principles of FBG sensors under space conditions and systematically classifies existing FBG-based SHM architectures, including point-based, multiplexed, long-distance, and hybrid sensing systems. Furthermore, the advantages of FBG sensors—such as immunity to electromagnetic interference, passive operation, and high-resolution multipoint sensing—are critically evaluated in comparison with traditional electrical sensors. In addition, key challenges affecting the performance of FBG systems in space environments are analyzed, including radiation-induced wavelength drift, temperature–strain cross-sensitivity, signal attenuation, and long-term stability issues. The paper also highlights recent advances in interrogation techniques and network architectures that enable reliable in situ and real-time deformation monitoring of space structures. The results demonstrate that FBG-based sensing systems provide a scalable and robust framework for SHM in extreme environments while also revealing existing limitations and open research challenges. This work establishes a structured foundation for the development of next-generation intelligent monitoring systems for space infrastructure. Full article

Different from isothermal amplification, for polymerase chain reaction (PCR), highly reliable valving for PCR chamber, significantly shortened thermal cycling time, and concise multiplexed detection are always challenges for microfluidic-based devices. Here, we present a real-time, centrifugal, plastic microfluidic chip for multiplexed PCR detection specifically based on the mechanism of cooperating valving. To achieve consistent amplification, a concise dual-valving strategy was developed. Instantly melted wax is centrifuged and completely filled into the narrow channel and hole to act as the compact wax valve. Meanwhile, an elastic and sticky membrane is depressed to seal the hole to act as the membrane valve. The wax valve is protected by the membrane valve from being damaged by both mechanical deformation and thermal corroding caused by the hot vapor with high pressure from the PCR chamber. A double-sided heating strategy is adopted to reduce the thermal cycling time; meanwhile, a balanced mechanism is used to achieve real-time amplification by rotating the centrifugal chip between the heating and detection positions in turn. As a proof-of-concept, the performance of the centrifugal chip with four parallel units is demonstrated by successfully detecting purified DNA templates or the extracted DNA templates from cells as well within 20 min. Full article

Terahertz (THz) fingerprint detection is central to identifying characteristic absorption fingerprints of biomolecules derived from their intrinsic rotational and vibrational modes. The development of guided-mode resonance (GMR) technology together with pixelated design offers a new approach to enhance the recognition capability of such fingerprint spectra. Here, a novel secondary grating metasurface based on cycloolefin polymer (COP) is proposed, which adopts an ultra-minimalist dual-pixel complementary architecture to excite high-quality (Q)-factor GMR. Its spectral resolution does not exceed 50 GHz, enabling precise capture of target molecular characteristic information and meeting the requirements of broadband fingerprint sensing. More importantly, the design regulates the dual-pixel grating units through parameter gradient optimization and incorporates a dual regulation mode of static pixel-targeted coverage and dynamic angle fine tuning. By adjusting geometric parameters and incident angles, broadband coverage from 1.15 THz to 2.20 THz is achieved, which can accurately match the multi-fingerprint detection requirements of glutamic acid (Glu) and glutamine (Gln). This metasurface sensor, integrating the advantages of pixelation and high-Q-factor GMR characteristics, provides an effective strategy for enhanced broadband THz fingerprint sensing and shows broad application potential in the field of biochemical trace detection. Full article

Osteoarthritis (OA) and osteochondral degeneration present a significant clinical burden characterized by the complex interplay of extracellular matrix degradation and chronic inflammation. While biochemical profiling has matured, a critical translational gap remains in transitioning from benchtop assays to systems capable of continuous, intra-articular monitoring. This review provides a comprehensive synthesis of experimentally validated biosensing technologies, including optical, electrochemical, and piezoelectric Quartz Crystal Microbalance (QCM) platforms, evaluated through the lens of sensing architecture, biomarker specificity, and matrix compatibility. Our analysis reveals that while optical sensors offer superior sensitivity, electrochemical platforms show the greatest promise for miniaturized, implantable integration. However, a pivot in the field is identified: the primary bottleneck has shifted from analytical detection limits to operational stability within the hostile synovial environment. Current research is largely restricted to single-analyte detection in simplified media, failing to address the multifactorial nature of OA. We propose that the next generation of osteochondral diagnostics must prioritize multiplexed arrays, mechanically compliant architectures, and machine-learning-assisted signal processing. By bridging these engineering frontiers, biosensors will evolve from passive diagnostic tools into intelligent, personalized platforms for real-time disease management. Full article

Toxoplasma gondii is an obligate intracellular parasite that infects virtually all warm-blooded animals, progressing through acute and chronic stages. The Akt/mTOR signaling axis plays critical roles in cell survival, proliferation, and metabolism, making it a key target for intracellular pathogens. This study investigated how T. gondii infection modulates this pathway during both infections. Outbred CD-1 mice were infected intraperitoneally with the virulent GT1 strain of T. gondii. Mice for acute studies were sacrificed five days post-infection, while those for chronic studies were treated with sulfadiazine and sacrificed five months post-infection. Phosphoprotein expression of eight Akt/mTOR pathway components was measured in liver tissues using a multiplexed bead-based immunoassay. Acute T. gondii infection caused broad suppression of Akt/mTOR signaling, with 6 of 8 markers significantly downregulated, including pS6RP^Ser235/236, pAKT^S473, pBAD^Ser136, pIRS1^S636/639, pPTEN^Ser380, and pGSK-3α/β^Ser21/9. In contrast, chronic infection related to cyst burden selectively activates specific nodes of the pathway, including pBAD^Ser136, pmTOR^Ser2448, and pGSK-3α/β^Ser21/9. Infection induced strong correlations between inter-components, which reflect coherent and coordinated pathway-level reprogramming rather than random perturbation. These findings show that acute and chronic T. gondii infections have opposing effects on host Akt/mTOR signaling for their own benefit, which may present new therapeutic targets. Full article

This paper proposes a data-driven framework to identify and rank economically connected cities by using commercial air traffic as a proxy for urban economic connectivity. The study is motivated by the limitation of traditional city classifications, which often rely on costly and multidimensional socioeconomic indicators, and by the need for scalable alternatives based on open mobility data. Using daily flight frequencies between 213 cities included in the GaWC classification for the year 2022, we built a time series for each origin–destination pair and unsupervised clustering these temporal profiles. The resulting clusters were used to define the layers of a multiplex network, where each layer represents a different pattern of flight connectivity. City importance was then estimated through Multiplex PageRank, which allows for temporal behavior and multilayer network structure to be combined in a single ranking scheme. Rather than introducing a new standalone algorithm, this paper contributes a reproducible analytical pipeline that integrates time-series clustering with multiplex centrality analysis using open aviation data. The results show that the ranking obtained is broadly aligned with established classifications such as GaWC, supporting the idea that commercial flight dynamics can provide a useful proxy for economic interconnectedness. The proposed approach offers a simple and replicable tool for comparative urban analysis, although the results should be interpreted with caution given the limited post-pandemic period covered by the data. Full article

Background: Lung cancer is the top cause of cancer-related mortality globally, and chemo-immunotherapy is a core therapeutic strategy for it. The novel bacterial composite vaccine (Neo-BCV) we developed previously can activate anti-tumor immunity. This study explored its synergistic anti-tumor effect with cisplatin (CDDP), along with the underlying immunomodulatory mechanisms and molecular regulatory networks. Methods: A murine Lewis lung cancer (LLC) model was established to evaluate the efficacy of the combination therapy. Flow cytometry and multiplex cytokine assay were used to detect immune cell subsets and functional molecules in the spleen, serum and tumor tissues. RNA-sequencing (RNA-seq) was used to elucidate the molecular regulatory networks following the combination therapy in the tumor tissues. Body weight, blood indexes, serum biochemistry and H&E staining were monitored to verify biosafety. Results: Neo-BCV combined with CDDP achieved an 87.77% tumor growth inhibition rate, showing the most significant anti-tumor effect. The combination promoted DC maturation, enhanced effector immune cell infiltration, reduced immunosuppressive cells, upregulated Th1-type cytokines and downregulated CD8⁺ T cell surface PD-1. RNA-seq confirmed enrichment of multiple immune effector pathways, supporting tumor immune microenvironment remodeling. The combination alleviated CDDP-induced weight loss, had no obvious adverse effects on physiological indicators, and exhibited good biosafety. Conclusions: Neo-BCV combined with CDDP achieves enhanced anti-tumor efficacy and favorable biosafety in murine lung cancer models by regulating immune cell subsets and activating immune-related molecular pathways, providing a solid preclinical basis for its clinical translation in lung cancer treatment. Full article

Invasive fungal respiratory infections (IFRIs) remain a major cause of morbidity and mortality among immunocompromised patients, yet diagnosis continues to be hindered by nonspecific clinical features, limited sample accessibility, and the poor sensitivity or specificity of conventional tests. Microfluidic and microelectromechanical systems (MEMS)-based biosensing platforms have emerged as promising alternatives, enabling rapid, minimally invasive, and highly specific detection of fungal pathogens and host responses. Microfluidic nucleic acid and antigen assays allow on-chip amplification and immunodetection with reduced sample volumes and turnaround times, while CRISPR-enhanced systems further improve analytical sensitivity. Parallel advances in host response profiling—including transcriptomic, proteomic, and cytokine-based signatures—have demonstrated feasibility for integration into lab-on-a-chip platforms. MEMS-based technologies extend this potential by facilitating real-time analysis of exhaled volatile organic compounds, mechanical biosensing of fungal DNA and antigens, and in situ monitoring of device-associated biofilms. Translational studies highlight potential applications across intensive care, hematology–oncology, and transplant settings, as well as in outpatient monitoring of high-risk populations. However, several challenges remain, including limited multicenter validation, matrix-related biofouling effects, and a lack of standardization in fungal biomarker panels. Future directions include AI-driven interpretation of multianalyte data, multiplexed integration of host and pathogen markers, and development of fully cartridge-based systems for near-patient deployment. Collectively, these innovations may shift fungal diagnostics toward earlier, more precise, and patient-tailored interventions, improving outcomes in vulnerable populations. Full article

Background/Objectives: The selection of neoadjuvant therapy for patients with non-metastatic pancreatic adenocarcinoma remains challenging. Methods: We performed a single-institution, retrospective analysis of 79 patients who underwent resection of their pancreatic adenocarcinoma after receiving neoadjuvant therapy. Clinical and pathologic data were collected. Tumor fibrosis was quantified using Masson’s trichrome staining, tumor-infiltrating lymphocytes (TIL) were evaluated by an AI-based analysis of whole-slide H&E images, and immune cell populations were quantified by multiplex immunohistochemistry. Correlation analyses were performed between neoadjuvant treatment regimen, tumor regression, immune phenotypes, and survival. Results: All patients received chemotherapy, 77% FOLFIRINOX and 23% Gemcitabine/nab-paclitaxel (Abraxane). Eighteen percent of patients went on to receive radiation. Tumor regression grade (TRG) correlated with the neoadjuvant regimen. A reduction in tumor markers and the baseline neutrophil-to-lymphocyte ratio (NLR) correlated with overall survival. Among patients with an NLR > 3.3, FOLFIRINOX conferred a survival benefit over Gemcitabine/nab-paclitaxel, and radiation trended towards improved survival. Radiation was associated with increased fibrosis and reduced infiltration of CD8⁺ and regulatory T cells (Tregs). Increased Tregs and PDL1⁺ stromal cells were associated with poor response to neoadjuvant therapy, and NLR > 3.3 correlated with increased Treg infiltration. Conclusions: Our data suggest that patients with a high baseline NLR may benefit from intensified neoadjuvant therapy with FOLFIRINOX and radiation. Combination immunotherapy targeting Tregs and the PD1/PDL1 axis may further improve outcomes. Full article

We propose a terahertz achromatic polarization-multiplexed structured light metasurface based on the particle swarm optimization (PSO) algorithm, operating from 0.8 to 0.95 THz. A dielectric silicon meta-atom array combined with propagation phase modulation is employed to achieve broadband wavefront control under two orthogonal linear polarizations. By constructing a phase-response database and using PSO for global optimization of phase compensation factors at multiple frequencies, the metasurface simultaneously satisfies different target phase profiles while suppressing chromatic aberration. Two multifunctional devices are designed. The first generates a conventional focused spot under x-polarized incidence and a first-order Bessel beam under y-polarized incidence. The second produces a focused vortex beam with topological charge l = 1 under x polarization and a focused vortex beam with l = 2 under y polarization. Full-wave simulations demonstrate stable focal positions, low inter-channel crosstalk, and good achromatic performance across the operating band. The Bessel beam preserves its nondiffracting core, while both vortex channels exhibit clear phase singularities and well-defined orbital angular momentum states. Most operating frequencies maintain relatively high focusing efficiency. Compared with conventional cascaded optical components, our design provides a compact and stable platform for terahertz structured light generation, orbital angular momentum multiplexing, nondiffracting imaging, and multidimensional polarization information processing. Full article

Sweat is a valuable biofluid for non-invasive health monitoring, as it contains electrolytes, metabolites, and organic compounds that can correlate with blood levels, making it highly attractive for wearable sensing. Building on advances in low-cost, portable electrochemical sensors, sweat analysis enables tracking of hydration status, metabolic stress, and energy availability via key markers such as sodium, potassium, lactate, and glucose. In the sports context, such wearable platforms can support performance optimization and recovery by assessing fluid loss and electrolyte balance in real time. Here, a multiplexed wearable sweat patch is developed to simultaneously monitor temperature, pH, ammonium, sodium, and sweat rate. The integrated platform demonstrates sensitivities of 10.1 mV/ln[NH₄⁺], 9.1 mV/ln[K⁺], 1.11 mV/ln[Na⁺], 14 mV/pH, 0.19% °C⁻¹, and approximately −1.0 mA (mL/min)⁻¹ for sweat rate, with stable signals and linear calibration responses over relevant physiological ranges. The sensor is implemented on a lightweight, biocompatible laser-scribed graphene on a PDMS substrate suitable for prolonged skin contact and mechanical deformation. In addition, a custom PDMS adhesive patch with optimized suction-cup microstructures is engineered to improve skin adhesion under both dry and wet conditions. Finally, the design of the platform was inspired by an adaptive cycling marathon across Saudi Arabia, where an earlier prototype of a wearable patch was deployed for real-time monitoring during a 30-day campaign. Full article

Simultaneous quantification of ascorbic acid, dopamine, and uric acid is crucial for clinical diagnostics. Here, an electrochemical sensor was developed by modifying a glassy carbon electrode with a ternary composite of multi-walled carbon nanotubes, graphene, and Vulcan XC72 carbon black via a simple mixing method. The synergistic interaction of these carbon materials significantly increases the electroactive surface area and introduces defect-driven catalytic sites, enhancing electron transfer kinetics. The sensor enables interference-free simultaneous detection, exhibiting linear ranges of 100–1000 μM ascorbic acid, 5–50 μM dopamine, and 10–100 μM uric acid with sensitivities of 0.044, 0.47, and 0.95 μA μM⁻¹, respectively, and corresponding limits of detection of 34.1, 4.23, and 11.1 μM. The platform also demonstrated excellent stability, reproducibility, and anti-interference performance, with satisfactory recoveries in human urine samples. These results highlight the ternary composite sensor as a reliable and practical tool for multiplexed monitoring in complex physiological matrices. Full article

Background: Intrathecal IgG synthesis is a well-established hallmark of multiple sclerosis (MS), yet the roles of other immunoglobulin isotypes remain under investigated. This study aimed to comprehensively profile immunoglobulin distributions in cerebrospinal fluid (CSF) and plasma from MS patients and neurological controls. Methods: Paired CSF and plasma samples from 23 MS patients and 20 neurological controls were analyzed using a multiplex Luminex-based immunoassay targeting IgG1–4, IgA, and IgM. The findings were validated using commercial ELISA kits and Western blot analysis. Results: Multiplex analysis revealed a selective intrathecal enrichment of IgA and IgM in MS CSF, with significantly higher levels compared to both matched plasma and control CSF. IgG1 was modestly elevated in MS CSF by ELISA but not by multiplex assay. Western blotting confirmed a robust elevation of IgA in MS CSF, providing qualitative support for intrathecal enrichment rather than definitive proof of synthesis. Conclusions: These findings uncover previously underappreciated selective enrichment of IgA and IgM in the MS CNS compartment, complementing, rather than replacing, the established IgG-centric paradigm. The results suggest alternative antibody-mediated mechanisms in MS and highlight the importance of assay selection in biomarker discovery, which suggests IgA as an emerging component of MS immunopathology. Full article

To combat poultry meat adulteration, we developed a poultry universal primer-based fluorescent PCR (PUP-fPCR). Through comprehensive genomic alignment analysis, a poultry-specific nuclear DNA sequence containing phylogenetically conserved regions and hypervariable segments with interspecies nucleotide polymorphisms was employed to develop universal primers targeting conserved flanking sequences and TaqMan probes for hypervariable segments. Then, a multiplex quantitative PCR method incorporating universal primers with four TaqMan probes was developed with high specificity and sensitivity (limit of detection: 0.005 ng). Analytical performance evaluation using prepared DNA mixtures revealed robust accuracy (relative deviation: 0.80–5.05%) and precision (relative standard deviation: 0.94–13.84%). This single-tube multiplex system leverages the spectral discrimination of TaqMan probes to simultaneously detect four poultry species, overcoming primer competition issues inherent in conventional multiplex PCR designs. This integrated approach reduces system complexity while maintaining detection efficiency, providing regulatory agencies with a robust tool for combating meat adulteration and ensuring food quality supervision. Full article