Search Results (398)

Polarimetric information is essential for scattering interpretation and target characterization in synthetic aperture radar (SAR) remote sensing, yet many resource-constrained platforms (e.g., small satellites and unmanned aerial vehicles (UAVs)) operate with limited polarization modes or even a single radio frequency (RF) chain, which limits full polarimetric scattering acquisition. To address this limitation, this paper proposes a single-channel framework for estimating the full polarization scattering matrix (PSM) enabled by time-varying polarization modulation. The transmit/receive polarization states are steered along predefined trajectories on the Poincaré sphere to generate time-varying polarization tags that are encoded into the received echoes through the target’s polarization-varying response. A compact observation model is then derived to relate the single-channel echoes, the known polarization tags, and the unknown PSM; based on this, the PSM is then estimated via a least squares formulation with a low-rank approximation. Simulation results demonstrate the robust reconstruction of the full polarimetric scattering matrix under diverse modulation trajectories. For arbitrarily chosen random point targets, when the signal-to-noise ratio (SNR) exceeds −20 dB, the polarimetric similarity coefficient approaches 1, and the estimation errors of Pauli power components converge toward zero. Furthermore, the method’s reliability is validated on distributed vegetation clutter. Quantitative metrics demonstrate near-perfect statistical consistency, with polarimetric entropy and alpha angle errors within 0.14%. Overall, the proposed approach provides a practical pathway to enhance the availability of full polarimetric scattering information under limited-observation conditions, confirming its feasibility for downstream analysis in complex natural scenes while maintaining a single radio frequency (RF) chain architecture augmented by a polarization modulator. Full article

As critical end-effectors enabling the practical deployment of marine robotic systems, soft hands face persistent challenges including multi-finger asynchronization, unbalanced force distribution, and insufficient anti-disturbance robustness, compounded by constraints from soft material nonlinearity and harsh marine environmental disturbances. To address these limitations, this paper proposes a dexterous grasping method integrating coupled dynamical systems and adaptive force planning control, designed to enhance operational reliability in complex marine environments. An intermediate dynamic layer is embedded to ensure precise multi-finger synchronization, a hybrid force planning algorithm balances force uniformity and constraint satisfaction, and an adaptive controller synergizes with a Neo-Hookean model to compensate for nonlinear deviations. Simulations and physical experiments demonstrate that the method delivers excellent grasping stability and accuracy for uneven mass distribution targets such as cylinders and spheres, while balancing synchronization precision, constraint compliance, and anti-disturbance capability. Compared with the traditional coupled dynamical systems (DSs), the constraint violation is reduced by up to 18.2%, the friction force is increased by 4.0%, and the force distribution uniformity is improved by approximately 5.1%.Compared with the particle swarm optimization (PSO) strategy, the constraint violation is reduced by up to 50.5%, the friction force is increased by 40.9%, and the force distribution uniformity is also improved by about 5.1%. This work fills a key gap in balancing multiple performance metrics for marine soft hands, providing a reliable technical solution to accelerate the real-world deployment of marine robotic systems. Full article

Osteosarcoma, the most common malignant bone tumor in young individuals, often exhibits poor outcomes due to MDM2-mediated suppression of the p53 pathway. Whereas conventional MDM2 inhibitors block the p53–MDM2 interaction but frequently induce compensatory MDM2 upregulation, proteolysis-targeting chimeras (PROTACs) directly degrade MDM2 and bypass this limitation. Here, we investigated the anticancer efficacy of two MDM2-targeting PROTAC compounds, CL0144 and CL0174, in osteosarcoma models. In Saos-2 and U2OS cells, both PROTACs efficiently induced MDM2 degradation, leading to activation of p53 or p73 signaling, increased reactive oxygen species production, apoptotic cell death, and marked reductions in viability. PROTAC treatment also significantly suppressed proliferation, colony formation, sphere formation, migration, and invasion. In vivo, xenograft assays demonstrated robust tumor growth inhibition following PROTAC administration. Collectively, these findings demonstrate that MDM2-targeting PROTACs exert strong antitumor effects by degrading MDM2 and disrupting downstream oncogenic pathways, supporting their potential as a promising therapeutic strategy for osteosarcoma. Full article

The ability to precisely control the morphology of polylactide (PLA) microparticles is crucial for their biomedical applications, yet it is a challenge due to the interdependent nature of key parameters such as size, porosity, and surface topology. This study presents a systematic approach to fabricating PLA microparticles with tunable architecture via emulsion-solvent evaporation by investigating the interplay of polymer molecular weight (44–442 kDa), solution concentration (0.5–20% w/v), and porogen type (PEG, alkanes, lithium salts). We achieved precise size control from 5 to 500 μm, dictated by solution viscosity and the polymer’s crystallization tendency, with poly(L-lactide) yielding irregular particles and poly(D,L-lactide) forming perfect spheres. Furthermore, porogen selection was critical for porosity: alkanes enabled tailored pore networks, with longer chains (e.g., decane) producing larger pores via enhanced phase separation, whereas the double-emulsion method with Li₂CO₃ proved superior for macroporosity due to its slow leaching kinetics. This work provides a foundational guideline for the rational design of PLA microparticles with customized properties for targeted applications in drug delivery and tissue engineering. Full article

Autonomous in-space assembly using a free-flying robot can lead to residual vibrations and positioning errors of the target modules during the grasping process. This places stringent demands on end-effectors, which must tolerate large misalignments while maintaining high positioning accuracy. In this regard, this paper presents a novel self-centring mechanism, which consists of two self-centring fingers mounted on the end-effector and a double V-groove mechanism attached to the target module. The proposed compact structural design passively corrects substantial parallel offsets and angular misalignments between the end-effector and the module. A multi-point contact model consistent with this mechanism is then developed using the virtual sphere layer method to describe the self-centring process. This model incorporates a normal contact force model and a three-dimensional bristle frictional force model to characterise the multi-point bouncing contact behaviours during the self-centring process. Numerical simulations and experimental tests involving the grasping of a module with a single robotic arm confirm that the self-centring mechanism effectively eliminates initial misalignments, achieving sub-millimetre positioning accuracy. The measured parallel offsets and contact forces align closely with numerical predictions, with minor discrepancies attributed to environmental noise and vibrations from the elastic bungees in the gravity compensation system. Finally, the self-centring mechanism is applied to grasp two modules with a dual-arm robot in the Space Proximity Operations Test facility. The centroid displacements of the robot closely match the simulation results, further validating the accuracy of the proposed multi-point contact model. Full article

LED diffuse-illumination systems are widely used in industrial inspection and real life because of their scattering properties. However, there has been little research on secondary optical designs for diffuse illumination. Considering the need for diffuse light in real life and work, combined with existing specular-reflection technology, this study proposes a design method for a combined-freeform-surface illumination system with specular and diffuse reflections. Considering that a separate diffusing device cannot effectively control the diffusion area of the light source, the unique properties of the specular-reflective device were utilized in this study. First, the specular-reflection device directs the light from the central portion of the LED to the diffuse-reflection device, and the light collected is then redistributed by the diffuse-reflection device. Two mathematical models were established according to the light-emitting angle of the LED, which corresponded to two freeform surfaces. In addition, when evaluating the uniformity of the target-plane illumination, a set of constraint equations was added to obtain the diffuse freeform surface contour of the target plane. Finally, the ratio of the diameter to the thickness of the resulting illumination system exceeded six, and the illumination uniformity increased to over 56% (with a uniformity improvement ratio of ≥6% compared to traditional single-freeform-surface systems and ≥10% compared to integrating sphere systems). It is specifically designed for industrial precision inspection scenarios, has higher illumination uniformity than other diffuse illumination systems, and has better compactness, making it suitable for high-precision inspection lighting applications. Full article

Ni removal from waste streams wherein it is present in organically complexed forms remains a major industrial challenge since organically bound Ni does not readily precipitate and is poorly removed by conventional adsorbents. In this work, two effective adsorbents, namely thin-layered porous carbon (TLPC) and MnO₂-decorated TLPC (i.e., MnO₂-TLPC), were developed for the removal of both inorganic and organically complexed Ni(II) from synthetic and real waste streams. Both adsorbents removed inorganic Ni(II) as well as Ni(II) present in organically complexed forms, achieving up to ~80% removal from both real and synthetic electroplating wastewater. Critically, Ni removal efficiencies were maintained over five adsorption–desorption cycles, demonstrating excellent regeneration and reuse potential. The Ni removal by TLPC was pH-dependent, whereas MnO₂-TLPC showed minimal pH sensitivity. TLPC relies on outer-sphere, charge-driven adsorption, whereas MnO₂-TLPC achieves stronger Ni binding through inner-sphere complexation promoted by oxygen- and nitrogen-based functional groups. The sorbents also reduced dissolved organic carbon, with TLPC displaying higher organic removal efficiency. Mechanistic analysis indicates that Ni uptake is primarily governed by sorption of both complexed and inorganic Ni(II) present in equilibrium with the complex, combined with sorption of the free ligand itself. The sorption of the free ligands and inorganic Ni(II) drive Ni–ligand decomplexation in the solution phase, enabling further Ni removal. Overall, TLPC provides a low-cost, high-performance option for treating alkaline wastewaters with elevated Ni and organic loadings, while MnO₂-TLPC offers robust, pH-resilient removal under circumneutral conditions. These findings position both materials as promising candidates for practical wastewater treatment applications targeting complexed metal contaminants. Full article

Neoadjuvant chemoimmunotherapy has emerged as a promising treatment strategy for head and neck squamous cell carcinoma (HNSCC). There is an urgent need to improve patient responses to this approach. In this study, we aim to elucidate the mechanisms underlying poor response to neoadjuvant chemoimmunotherapy and to identify strategies to enhance therapeutic efficacy in HNSCC. We identified a cancer stem-like cell (CSC) population enriched in patients with partial response (PR) to neoadjuvant chemoimmunotherapy, characterized by high CD80 expression. CD80 was likewise highly expressed in ALDH^highCD44⁺ and BMI1⁺ populations. Functionally, CD80 knockdown attenuated tumor-sphere-forming capacity and reduced the migration and invasion of tumor cells, whereas CD80 overexpression potentiated these pro-tumorigenic activities. Moreover, CD80 inhibition activated signaling pathways of Th1 immune responses and IL-2 production. CD80 blockade enhanced T cell cytotoxicity. In preclinical HNSCC models, inhibition of CD80 significantly decreased tumor burden, accumulated CD8⁺ T cells, and increased the production of cytotoxic effector molecules. Our data demonstrated that CD80 modulated tumor-cell stemness and malignant phenotype while restraining antitumor T cell immunity. Targeting CD80 augments antitumor immunity and provides a compelling strategy to enhance treatment responses to neoadjuvant chemoimmunotherapy in HNSCC. Full article

Background: Metastasis and recurrence account for the failure of nasopharyngeal carcinoma (NPC) treatment. Growing evidence indicates the dominant roles of cancer stem cells (CSCs) in tumor progression and therapy resistance. However, the heterogeneity of CSCs and potential stemness-related markers in NPC patients are still largely unknown. Methods: Consensus clustering was first applied to identify robust stemness subtypes for NPC patients based on the activities of stem cell gene sets. The differences in clinical outcomes, tumor immune microenvironment (TIME), and drug response were compared between subtypes. The stemness-related markers were prioritized via weighted gene correlation network analysis (WGCNA) and Cox regression, and verified through in vitro experiments. Results: NPC patients were classified into C1 and C2 subtypes. The C2 subtype exhibited higher activities of stem cell gene sets, worse prognosis, and aggressive tumor progression thus defined as stem cell-like tumor phenotype. The exclusionary relationships between tumor stemness and TIME infiltration were observed. The efficacy of several drugs and immunotherapy varied between NPC stemness subtypes. Through the WGCNA and survival analysis, we found that PSMC3IP, NABP2, CDC45, and HJURP were stemness-relevant genes. Sphere formation assays and analysis of the protein expression of stem cell markers by Western blotting revealed the roles of PSMC3IP, NABP2, CDC45, and HJURP in promoting CSC properties. Moreover, these genes were found to be related to the therapeutic effect of telomerase inhibitor in CCK8 experiments. Conclusions: This study systematically characterized two NPC subtypes with distinct stemness features, clinical outcomes, and TIME features. Novel stemness-related markers will provide valuable targets against metastatic or recurrent NPC. Full article

High-precision centering alignment of the lens is crucial for ensuring the imaging quality of refractive optical systems. A multi-zone computer-generated hologram (MZ-CGH) was designed and utilized for centering a large-aperture refractive infrared lens. Different from traditional methods that use the line connecting the geometric centers of lens spheres as the optical axis for alignment, the minimization of transmitted wavefront aberrations detected via interferometry is employed as the target for lens centering. According to the structure design, the large-aperture lens is divided into a front barrel integrated with lenses 1–3, a back barrel integrated with lenses 4–5, and a separated lens 6. An MZ-CGH contains three main zones with compensation information for testing the transmitted wavefront of lenses 1–3, according to the alignment and centering sequence. The method is applied to align and analyze errors in an infrared optical system with a clear aperture of 400 mm, achieving lens decenter errors better than 5 μm. After alignment, the wavefront errors of the infrared optical system within ±7° of the field of view are better than RMS 0.07λ, with an average MTF higher than 0.5, demonstrating significant value for engineering applications. Full article

Noncontact, high-fidelity data acquisition has enabled terrestrial laser scanning (TLS) to be widely adopted for bridge geometry measurement and condition monitoring. In TLS applications, point cloud registration directly affects data quality and the correctness of subsequent results. For long-span bridges in large-scale scenes, complex geometry and sparse sampling pose challenges to surface-based, data-driven registration methods, and may degrade registration accuracy. A data-driven approach for high-precision point cloud registration, referred to as the Iterative Closest-Surface (IC-Surface) method, is presented in this study. The method extracts neighboring surface patches via a bounding box and applies random sampling-based plane fitting to derive surface features for registration, effectively mitigating the impact of sparse points and outliers in long-span bridges. Regular points are generated on the source patch and projected onto the corresponding target patch to establish high precision correspondences, yielding a stable and accurate transformation. This method effectively overcomes the limitations of the Iterative Closest Point (ICP), which struggles with unreliable correspondences and outliers. Comparative experiments were conducted using synthetic data, large bridge segments, and full-bridge datasets against commonly used registration methods. The results show that the IC-Surface method maintains high accuracy and stability across varying levels of outliers and overlap ratios. In complex scenes, IC Surface achieves higher registration accuracy than both ICP and the sphere target method, with distance errors reduced from 3 mm to 1 mm and inter-plane angle errors reduced from 0.016 rad to 0.009 rad. These findings demonstrate the method’s broad applicability in digital construction and operation and maintenance assessments of long-span bridges. Full article

Colorectal cancer (CRC) progression and therapy resistance are driven in part by metabolic reprogramming and the persistence of cancer stem-like cells (CSCs). The seven in absentia homolog 2 (SIAH2)/with-no-lysine kinase 1 (WNK1) signaling axis has emerged as a potential regulator of these processes, yet its functional role in CRC metabolism and tumor–stroma crosstalk remains incompletely understood. Integrated analyses of The Cancer Genome Atlas–Colon Adenocarcinoma (TCGA-COAD) and Gene Expression Omnibus (GEO, GSE17538) datasets revealed significant upregulation of SIAH2 and WNK1 in CRC tissues, with strong positive correlations to glycolysis- and hypoxia-associated genes, including PFKP, LDHA, BPGM, ADH1A, ADH1B, and HIF-1α. Single-cell and clinical profiling further demonstrated preferential enrichment of SIAH2 in undifferentiated, stem-like tumor cell populations. Functional studies across multiple CRC cell lines showed that SIAH2 silencing suppressed proliferation, clonogenic growth, tumor sphere formation, and cell-cycle progression, whereas SIAH2 overexpression exerted opposite effects. Seahorse extracellular flux analyses established that SIAH2 promotes glycolytic capacity and metabolic flexibility. At the protein level, SIAH2 regulated glycolytic enzymes and WNK1/hypoxia-inducible factor-1α (HIF-1α) signaling, effects that were amplified by cancer-associated fibroblast (CAF)-derived conditioned medium. CAF exposure enhanced SIAH2 expression, CSC spheroid growth, and resistance to fluorouracil, leucovorin, and oxaliplatin (FOLFOX) chemotherapy, whereas SIAH2 depletion effectively abrogated these effects. Collectively, these findings identify the SIAH2/WNK1 axis as a central metabolic regulator linking glycolysis, CSC maintenance, and microenvironment-driven therapy resistance in CRC, highlighting its potential as a therapeutic target. Full article

This paper presents a multichannel electronics measurement system that uses microwave sensors to perform real-time microplastics assessment in aqueous environments. The system is capable of simultaneously reading up to four microwave sensors, enabling the use of multiple sensors that target microplastic particles with different sizes and properties. The multichannel capability allows the measurement of multiple MW sensors integrated with different microfluidic channel designs while targeting different MPs’ dimension ranges, although experimental validation in this work was limited to a single sensor. Each readout channel is implemented combining radio-technology-integrated circuits with a microprocessor that has advanced analog peripherals used for signal conditioning and acquisition. An ADF4351 wideband frequency synthesizer is used for excitation signal generation while an ADL5902 power detector converts the sensor output to a DC voltage. Baseline removal and amplification of the power detector output is realized with a MSP430FR2355 microprocessor which is also responsible for its acquisition at 40 kHz and digital decimation. Characterization results show the system’s capability to generate excitation signals between 700 MHz and 3.5 GHz with power levels around 0 dBm. Sensor output can be detected with a power between −50 dBm and −5 dBm and a 230 Hz bandwidth. A compact form factor of 15 cm × 10 cm × 3 cm was realized together with a low power consumption of 6.6 W. Validation was realized with a previously developed microwave sensor, demonstrating the detection of polyethylene spheres with 400 μm diameters animated in 10 mL/min flux within the microfluidics device. Full article

Cancer stem cells (CSCs) represent a small but highly resilient tumor subpopulation responsible for sustained growth, metastasis, therapeutic resistance, and recurrence. Their survival is supported by aberrant activation of developmental and inflammatory pathways, including Wnt/β-catenin, Notch, Hedgehog, PI3K/Akt/mTOR, STAT3, and NF-κB, as well as epithelial–mesenchymal transition (EMT) programs and niche-driven cues. Increasing evidence shows that phytochemicals, naturally occurring bioactive compounds from medicinal plants, can disrupt these networks through multi-targeted mechanisms. This review synthesizes current findings on prominent phytochemicals such as curcumin, sulforaphane, resveratrol, EGCG, genistein, quercetin, parthenolide, berberine, and withaferin A. Collectively, these compounds suppress CSC self-renewal, reduce sphere-forming capacity, diminish ALDH⁺ and CD44⁺/CD24⁻ fractions, reverse EMT features, and interfere with key transcriptional regulators that maintain stemness. Many phytochemicals also sensitize CSCs to chemotherapeutic agents by downregulating drug-efflux transporters (e.g., ABCB1, ABCG2) and lowering survival thresholds, resulting in enhanced apoptosis and reduced tumor-initiating potential. This review further highlights the translational challenges associated with poor solubility, rapid metabolism, and limited bioavailability of free phytochemicals. Emerging nanotechnology-based delivery systems, including polymeric nanoparticles, lipid carriers, hybrid nanocapsules, and ligand-targeted formulations, show promise in improving stability, tumor accumulation, and CSC-specific targeting. These nanoformulations consistently enhance intracellular uptake and amplify anti-CSC effects in preclinical models. Overall, the consolidated evidence supports phytochemicals as potent modulators of CSC biology and underscores the need for optimized delivery strategies and evidence-based combination regimens to achieve meaningful clinical benefit. Full article

Rural transport remains a critical factor of social inclusion in South Africa, particularly for people with disabilities who rely on public transport. This study explores the experiences of minibus taxi drivers in transporting passengers with disabilities in Mt Elias, a rural community in the KwaZulu-Natal province. A qualitative research design was adopted, involving semi-structured interviews with 15 drivers operating between Dalton and Mt Elias route. Thematic analysis was conducted using ATLAS.ti to identify key patterns and relationships across the dataset. The four key themes that emerged from the dataset are: infrastructure and environmental challenges, accessibility and support for passengers, operational and economic constraints, and human interactions and attitudes. Findings reveal that drivers face multiple barriers, including poor road conditions, limited vehicle space, and a lack of formal training, yet many demonstrate empathy and commitment to assisting passengers with disabilities. The study highlights the need for targeted policy interventions to improve road infrastructure, provide disability awareness training for drivers, and redesign vehicles for accessibility. Promoting inclusive rural transport requires coordinated action among government spheres, taxi associations, and disability advocacy groups. This research contributes new insights into the lived realities of rural drivers and promotes the importance of inclusive mobility as a component of social justice. Full article