Search Results (21)

Extended object tracking (EOT) has emerged as a critical challenge in modern surveillance and autonomous systems, where high-resolution sensors yield multiple measurements per target in a single scan. This task necessitates the simultaneous estimation of an object’s spatial extent and kinematic states by systematically assimilating distributed detections. In practical scenarios, however, sensor visibility constraints often restrict measurements to partial contours rather than the full object geometry, posing a significant hurdle for accurate state estimation. This paper proposes a robust EOT algorithm that addresses these challenges by extracting elliptical features—including size, orientation, and noise characteristics—in an affine-invariant manner from incomplete measurement sets. By formulating the ellipse-fitting problem through an algebraic solution, the proposed method effectively reconstructs the target’s morphology even under severe self-occlusion. The tracking framework is established as a Bayesian inference problem, utilizing a standard Kalman filter as a recursive estimator to ensure both computational efficiency and numerical robustness. In Monte Carlo simulations in which measurements are restricted to the sensor-facing contour, the proposed method reduces the average extent estimation error, quantified by the Gaussian Wasserstein distance, to 9.15 m, compared with 64.84–70.62 m for three state-of-the-art baselines, while retaining real-time feasibility with an average processing time of 0.94 ms per scan. Experiments on real-world LiDAR vehicle-tracking data further confirm consistent and accurate extent estimation under partial observability and complex maneuvers. Full article

Objectives: This study aimed to develop curcumin nanoparticles (Cur@PCL-PEG-MF/cRGDfc) with retinal-targeting capability and to evaluate their biological effects and pharmacological mechanisms in vitro. Methods: After synthesis of the carrier framework, metformin (MF) and cRGDfc were conjugated to the carrier material using the carbodiimide method and Michael addition reaction, respectively. Subsequently, self-assembled nanoparticles were formed from the carrier and curcumin under specific conditions. The materials were characterized by spectroscopy, chromatography, elemental analysis, energy-dispersive spectroscopy and X-ray diffraction. The efficacy of the formulation was evaluated in two cell lines, ARPE-19 and HUVEC-T1. In addition, the pharmacological mechanism was explored using transcriptome sequencing as a complementary approach. Key Findings: Self-assembled nanoparticles were successfully prepared by combining the two modified carrier materials, PCL-PEG-MF and PCL-PEG-cRGDfc, with curcumin. The nanoparticles exhibited an encapsulation efficiency of 78.09%, a particle size of 162.33 nm, and a zeta potential of −23.28 mV and displayed a spherical morphology. They showed sustained release in simulated physiological conditions and stronger affinity for ARPE-19 cells under oxidative stress. Nearly 100% of the nanoparticles were internalized by the cells, which was accompanied by reduced ROS and LDH release and decreased DNA fragmentation. In addition, the nanoparticles inhibited neovascularization by reducing VEGF-A release, thereby potentially protecting the retina in macular degeneration and reducing choroidal hemorrhage. Further analyses showed that curcumin and its nanoformulations significantly reduced the expression of inflammatory factors such as IL-1β and IL-18, lowered the protein levels of Caspase-1, GSDMD-N, and NLRP3, and increased AMPK levels. Conclusions: Using PCL-PEG as the carrier framework, MF and cRGDfc were conjugated to construct a curcumin-loaded nanoparticle with retinal-targeting capability. This nanoparticle, characterized by a small particle size, sustained release, and targeted delivery to retinal pigment epithelium (RPE) cells under oxidative stress, alleviated oxidative stress-induced damage. Its therapeutic effect may be mediated, at least in part, by interference with the AMPK/mTOR pathway and activation of the NLRP3/Caspase-1/GSDMD pathway. Full article

The morphology of solid surfaces encodes fundamental information about the physical mechanisms that govern their formation. Here, we reinterpret scanning electron microscopy (SEM) micrographs of oxide thin films as two-dimensional self-affine morphology fields (not height-metrology) and analyze them using a multiscale statistical-physics framework that integrates spectral, multifractal, geometric, and topological descriptors. Fourier-based power spectral density (PSD) provides the spectral slope $\beta$ and apparent Hurst exponent $H$, while multifractal scaling yields the information dimensions $D_q$, the singularity spectrum $f\left(\alpha \right)$, and its width $\mathsf{\Delta }\alpha$, which quantify scale hierarchy and intermittency. Lacunarity captures intermediate-scale heterogeneity, and Minkowski functionals—especially the Euler characteristic $\chi \left(\theta \right)$—probe connectivity and identify the onset of a percolation-like network structure. Two representative surfaces with contrasting morphologies are used as model systems: one exhibiting an anisotropic, porous, strongly multifractal structure with fragmented domains; the other showing a compact, nearly isotropic, and nearly monofractal organization. The porous surface/topography displays steep PSD decay, broad multifractal spectra, and positive $\chi$, consistent with a sub-percolated, diffusion-limited, Edwards–Wilkinson-like (EW-like) growth regime. Conversely, the compact surface/topography exhibits gentler spectral slopes, narrower $f\left(\alpha \right)$, enhanced lacunarity at intermediate scales, and a $\chi \left(\theta \right)$ zero-crossing indicative of a connectivity transition where a surface becomes a percolating network, consistent with a Kardar–Parisi–Zhang-like (KPZ-like) correlated growth regime. These results demonstrate that individual SEM micrographs encode quantitative fingerprints of nonequilibrium universality classes and topology-driven transitions from fragmented surfaces to connected networks, showing that SEM intensity maps can serve as a quantitative probe for testing theories of rough surfaces and kinetic growth in experimental thin-film systems. Full article

A detailed picture of how an aerosol is transported and deposited in the self-affine bronchial tree structure of patients is fundamental to design and optimize orally inhaled drug products. This work describes a Monte Carlo-based statistical deposition model able to simulate aerosol transport and deposition in a 3D human bronchial tree. The model enables working with complex and realistic inhalation maneuvers including breath-holding and exhalation. It can run on fully stochastically generated bronchial trees as well as on those whose proximal airways are extracted from patient chest scans. However, at present, a mechanical breathing model is not explicitly included in our trees; their ventilation can be controlled by means of heuristic airflow splitting rules at bifurcations and by an alveolation index controlling the distal lung volume. Our formulation allows us to introduce different types of pathologies on the trees, both those altering their morphology (e.g., bronchiectasis and chronic obstructive pulmonary disease) and those impairing their function (e.g., interstitial lung diseases and emphysema). In this initial activity we describe deposition and ventilation models as well as the stochastic tree construction algorithm, and we validate them against total, regional, lobar, and sub-lobar deposition for healthy subjects. Full article

Background/Objectives: This paper presents cranial MMS data for an American Indian (AI) sample from New Mexico. We compare these data to other population reference samples to understand biological distance and classification patterns. Methods: Cranial MMS data was collected from CT scans of AI individuals (n = 839) in the New Mexico Decedent Image Database. We used 12 traits following a published protocol for CT data and excluded nasal bone contour. The AI sample is compared to other samples of African American or Black, Asian, Hispanic, and White individuals to assess biological distance and classification accuracy. Results: Biological distance analysis indicated similarity among the AI, Hispanic, and Black samples, but dissimilarity among the Asian and White samples to the AI sample. Classification accuracy was low for the overall model, with Hispanic and Black individuals frequently misclassifying as AI. Conclusions: As is true everywhere, ideas about identity are complex in New Mexico. AI and Hispanic individuals in NM self-ascribe to one or both social groups. We found that biological data cannot meaningfully differentiate between these social groups, as crania are morphologically similar when examining cranial MMS traits. These results, coupled with New Mexican identity and genetics, contributes to the difficulty in group attribution in forensic casework. Nevertheless, the reference data for AI presented here can provide more robust statistics that support the likelihood of AI and Hispanic affinity in population affinity analysis. We underscore the need for an understanding of regional population history and structure and reference samples while assessing population affinity in forensic casework. Full article

A salient feature of modern material surfaces used in cutting-edge technologies is their structural and spatial complexity, which endows them with novel properties and multifunctionality. The quantitative characterization of material complexity is a challenge that must be addressed to optimize their production and performance. While numerous metrics exist to quantify the complexity of spatial structures in various scientific domains, methods specifically tailored for characterizing the spatial complexity of material surface morphologies at the micro- and nanoscale are relatively scarce. In this paper, we utilize the concept of multiscale entropy to quantify the complexity of surface morphologies of rough surfaces across different scales and investigate the effects of amplitude fluctuations (i.e., surface height distribution) in both stepwise and smooth self-affine rough surfaces. The crucial role of the binning scheme in regulating amplitude effects on entropy and complexity measurements is highlighted and explained. Furthermore, by selecting an appropriate binning strategy, we analyze the impact of 2D imaging on the complexity of a rough surface and demonstrate that imaging can artificially introduce peaks in the relationship between complexity and surface amplitude. The results demonstrate that entropy-based spatial complexity effectively captures the scale-dependent heterogeneity of stepwise rough surfaces, providing valuable insights into their structural properties. Full article

Multifunctional self-healing supramolecular structural toughened resins, formulated to counteract the insulating properties of epoxy polymers and integrating auto-repair mechanisms, are morphologically and spectroscopically characterized using Tunneling Atomic Force Microscopy (TUNA) and Fourier transform infrared spectroscopy (FT-IR), respectively. Specifically, the multifunctional resin comprises self-healing molecular fillers and electrically conductive carbon nanotubes (CNTs) embedded in the matrix. The selected self-healing molecules can form non-covalent bonds with the hydroxyl (OH) and carbonyl (C=O) groups of the toughened epoxy matrix through their H-bonding donor and acceptor sites. An FT-IR analysis has been conducted to evaluate the interactions that the barbiturate acid derivatives, serving as self-healing fillers, can form with the constituent parts of the toughened epoxy blend. Tunneling Atomic Force Microscopy (TUNA) highlights the morphological characteristics of CNTs, their dispersion within the polymeric matrix, and their affinity for the globular rubber domains. The TUNA technique maps the samples’ electrical conductivity at micro- and nanoscale spatial domains. Detecting electrical currents reveals supramolecular networks, determined by hydrogen bonds, within the samples, showcasing the morphological features of the sample containing an embedded conductive nanofiller in the hosting matrix. Full article

Achieving light-induced manipulation of controlled self-assembly in nanosized structures is essential for developing artificially dynamic smart materials. Herein, we demonstrate an approach using a non-photoresponsive hydrogen-bonded (H-bonded) macrocycle to control the self-assembly and disassembly of nanostructures in response to light. The present system comprises a photoacid (merocyanine, 1-MEH), a pseudorotaxane formed by two H-bonded macrocycles, dipyridinyl acetylene, and zinc ions. The operation of such a system is examined according to the alternation of self-assembly through proton transfer, which is mediated by the photoacid upon exposure to visible light. The host–guest complexation between the macrocycle and bipyridium guests was investigated by NMR spectroscopy, and one of the guests with the highest affinity for the ring was selected for use as one of the components of the system, which forms the host–guest complex with the ring in a 2:1 stoichiometry. In solution, a dipyridine and the ring, having no interaction with each other, rapidly form a complex in the presence of 1-MEH when exposed to light and thermally relax back to the free ring without entrapped guests after 4 h. Furthermore, the addition of zinc ions to the solution above leads to the formation of a polypseudorotaxane with its morphology responsive to photoirradiation. This work exemplifies the light-controlled alteration of self-assembly in non-photoresponsive systems based on interactions between the guest and the H-bonded macrocycle in the presence of a photoacid. Full article

Polymer microspheres with temperature and salt resistance were synthesized using the anti-suspension polymerization method, incorporating the functional monomers AMPS, AM, and AA. To enhance their self-gelling properties, the microspheres were designed with a core–shell structure. The shell is composed of a polymeric surfactant, fatty alcohol polyoxyethylene ether methacrylate (AEOMA), which serves as a thermosensitive crosslinking agent, enabling self-crosslinking upon shell decomposition, addressing compatibility with reservoir pore throat dimensions. Comprehensive characterizations including infrared spectroscopy, scanning electron microscopy, optical microscopy, and laser particle size analysis were conducted. The microspheres exhibited successful synthesis, a nanoscale size, and regular spherical morphology. They demonstrated excellent temperature and salt resistance, making them suitable for high-temperature, high-salinity reservoir profile control. With a stable three-dimensional network structure, the microspheres displayed good expansion behavior due to hydrophilic groups along the polymer chains, resulting in favorable water affinity. Even after aging, the microspheres maintained their gelling state with a distinct and stable microscopic network skeleton. They exhibited superior plugging performance in low-permeability reservoirs, while effectively improving water absorption profiles in reservoirs with permeability contrasts of 10 to 80, thereby enhancing oil recovery. Full article

Rigid polyurethane foams are the better-performing material for the most common insulation purposes, like sandwich panels. Nevertheless, they are highly flammable materials, release toxic gases, and are manufactured from fossil sources. As an alternative, tannin foams are bio-based materials that work as innovative alternatives thanks to their great fire resistance, as well as lower smoke and harmful gases emissions. In the present study, lab-made foams of both materials were compared through morphology, thermal and fire degradation, mechanical properties, and water affinity in order to fill the technological gap between them and their related sandwich panels. It was observed that tannin foams are still relatively inhomogeneous (since formaldehyde was not used) and present a high affinity for water but have higher thermal and fire resistance. The flat compression strength of the polyurethane sandwiches was greater than that of tannin sandwiches (3.61 and 3.09 MPa, respectively) thanks, mainly, to the crosslinking degree difference between the resins. Also, tannin foams presented a lower weight loss (−70.684% lower weight loss in flammability tests than polyurethane foams) and the ability to self-extinguish the flame. Therefore, sandwich panels with tannin foam cores could be successful materials in areas that require protection against fire, such as the building engineering and automotive industries. Full article

The effective control over the vesicle formation pathways is vital for tuning its function. Recently, a liquid–liquid phase-separated intermediate (LLPS) is observed before a vesicular structure during the solvent exchange self-assembly of block copolymers. Though the understanding of polymer structures and chemical compositions on the competition between LLPS and micellization has made some progress, little is known about the role of cosolvent on it. In this study, the influence of cosolvent on the vesicle formation pathways is investigated by using dissipative particle dynamics. The results show that the range of water fraction within which the LLPS is favored will be highly dependent on the affinity difference of cosolvent to water and to polymer repeat units. The change of the cosolvent–water interaction and the water fraction impact the distribution of cosolvent in the polymer domain, the miscibility between the components in the system as well as the chain conformations, which finally induce different self-assembly behaviors. Our findings would be helpful for understanding the LLPS and controlling the morphologies of diblock polymers in solutions for further applications. Full article

Idebenone (IDE), a synthetic short-chain analogue of coenzyme Q10, is a potent antioxidant able to prevent lipid peroxidation and stimulate nerve growth factor. Due to these properties, IDE could potentially be active towards cerebral disorders, but its poor water solubility limits its clinical application. Octanoyl-β-cyclodextrin is an amphiphilic cyclodextrin (ACyD8) bearing, on average, ten octanoyl substituents able to self-assemble in aqueous solutions, forming various typologies of supramolecular nanoassemblies. Here, we developed nanoparticles based on ACyD8 (ACyD8-NPs) for the potential intranasal administration of IDE to treat neurological disorders, such as Alzheimer’s Disease. Nanoparticles were prepared using the nanoprecipitation method and were characterized for their size, zeta potential and morphology. STEM images showed spherical particles, with smooth surfaces and sizes of about 100 nm, suitable for the proposed therapeutical aim. The ACyD8-NPs effectively loaded IDE, showing a high encapsulation efficiency and drug loading percentage. To evaluate the host/guest interaction, UV-vis titration, mono- and two-dimensional NMR analyses, and molecular modeling studies were performed. IDE showed a high affinity for the ACyD8 cavity, forming a 1:1 inclusion complex with a high association constant. A biphasic and sustained release of IDE was observed from the ACyD8-NPs, and, after a burst effect of about 40%, the release was prolonged over 10 days. In vitro studies confirmed the lack of toxicity of the IDE/ACyD8-NPs on neuronal SH-SY5Y cells, and they demonstrated their antioxidant effect upon H₂O₂ exposure, as a general source of ROS. Full article

This article reports findings on screen-printed electrodes employed in microfluidic diagnostic devices. The research described includes developing a series of graphene- and other carbon form-based printing pastes compared to their rheological parameters, such as viscosity in static and shear-thinning conditions, yield stress, and shear rate required for thinning. In addition, the morphology, electrical conductivity, and electrochemical properties of the electrodes, printed with the examined pastes, were investigated. Correlation analysis was performed between all measured parameters for six electrode materials, yielding highly significant (p-value between 0.002 and 0.017) correlations between electron transfer resistance (Ret), redox peak separation, and static viscosity and thinning shear-rate threshold. The observed more electrochemically accessible surface was explained according to the fluid mechanics of heterophase suspensions. Under changing shear stress, the agglomeration enhanced by the graphene nanoplatelets’ interparticle affinity led to phase separation. Less viscous pastes were thinned to a lesser degree, allowing non-permanent clusters to de-agglomerate. Thus, the breaking of temporary agglomerates yielded an unblocked electrode surface. Since the mechanism of phase ordering through agglomeration and de-agglomeration is affected by the pastes’ rheology and stress during the printing process and requires no further treatment, it can be appropriately labeled as a self-assembling electrode material. Full article

We report the synthesis of poly(styrene-block-lactic acid) (PS-b-PLA) copolymers with triazole rings as a junction between blocks. These materials were prepared via a ‘click’ strategy which involved the reaction between azide-terminated poly(styrene) (PS-N₃) and acetylene-terminated poly(D,L-lactic acid) (PLA-Ac), accomplished by copper-catalyzed azide-alkyne cycloaddition reaction. This synthetic approach has demonstrated to be effective to obtain specific copolymer structures with targeted self-assembly properties. We observed the self-assembly behavior of the PS-b-PLA thin films as induced by solvent vapor annealing (SVA), thermal annealing (TA), and hydrolysis of the as-spun substrates and monitored their morphological changes by means of different microscopic techniques. Self-assembly via SVA and TA proved to be strongly dependent on the pretreatment of the substrates. Microphase segregation of the untreated films yielded a pore size of 125 nm after a 45-min SVA. After selectively removing the PLA microdomains, the as-spun substrates exhibited the formation of pores on the surface, which can be a good alternative to form an ordered pattern of triazole functionalized porous PS at the mesoscale. Finally, as revealed by scanning electron microscopy–energy dispersive X-ray spectroscopy, the obtained triazole-functionalized PS-porous film exhibited some affinity to copper (Cu) in solution. These materials are suitable candidates to further study its metal-caption properties. Full article

In the present study, the microstructural and statistical properties of unimplanted in comparison to argon ion-implanted tantalum-based thin film surface structures are investigated for potential application in microelectronic thin film substrates. In the study, the argon ions were implanted at the energy of 30 keV and the doses of 1 × 10¹⁷, 3 × 10¹⁷, and 7 × 10¹⁷ (ion/cm²⁾ at an ambient temperature. Two primary goals have been pursued in this study. First, by using atomic force microscopy (AFM) analysis, the roughness of samples, before and after implantation, has been studied. The corrosion apparatus wear has been used to compare resistance against tantalum corrosion for all samples. The results show an increase in resistance against tantalum corrosion after the argon ion implantation process. After the corrosion test, scanning electron microscopy (SEM) analysis was applied to study the sample morphology. The elemental composition of the samples was characterized by using energy-dispersive X-ray (EDX) analysis. Second, the statisticalcharacteristics of both unimplanted and implanted samples, using the monofractal analysis with correlation function and correlation length of samples, were studied. The results show, however, that all samples are correlated and that the variation of ion doses has a negligible impact on the values of correlation lengths. Moreover, the study of height distribution and higher-order moments show the deviation from Gaussian distribution. The calculations of the roughness exponent and fractal dimension indicates that the implanted samples are the self-affine fractal surfaces. Full article