Shape Properties Research Articles

Design and verification of a single-degree-of-freedom driven deformable wheel mechanism

Abstract. Improving the obstacle-crossing ability of special vehicles in complex environments is essential for emergency rescue and security operations. To address this need, a single-degree-of-freedom driven deformable wheel mechanism is proposed, which enables efficient wheel diameter adjustment and a high expansion ratio. First, the degrees of freedom of single-vertex and multi-vertex origami mechanisms are analyzed using the Jacobian matrix method, and then a kinematic model is developed using the improved Denavit–Hartenberg (D–H) method to provide theoretical support for the motion characteristics. Next, a comprehensive performance analysis is conducted, including evaluations of stiffness, expansion ratio, and motion. The mechanism's reliability and adaptability are verified through finite-element and dynamic simulations. In the experimental phase, a prototype of the deformable wheel is fabricated using additive manufacturing technology, and the selected resin material not only ensures excellent processing and shaping properties but also offers a lightweight design and structural stability, effectively enhancing the wheel's expansion performance and overall stiffness. Finally, through expansion ratio testing and performance verification, experimental results demonstrate that the proposed mechanism design features fewer driving components, a high expansion ratio, and strong environmental adaptability. This study provides a possible solution for the design of deformable wheels from the perspective of the feasibility of deployable mechanisms.

Classification of Renal Lesions by Leveraging Hybrid Features from CT Images Using Machine Learning Techniques.

Renal cancer is amid the several reasons of increasing mortality rates globally, which can be reduced by early detection and diagnosis. The classification of lesions is based mostly on their characteristics, which include varied shape and texture properties. Computed tomography (CT) imaging is a regularly used imaging modality for study of the renal soft tissues. Furthermore, a radiologist's ability to assess a corpus of CT images is limited, which can lead to misdiagnosis of kidney lesions, which might lead to cancer progression or unnecessary chemotherapy. To address these challenges, this study presents a machine learning technique based on a novel feature vector for the automated classification of renal lesions using a multi-model texture-based feature extraction. The proposed feature vector could serve as an integral component in improving the accuracy of a computer aided diagnosis (CAD) system for identifying the texture of renal lesion and can assist physicians in order to provide more precise lesion interpretation. In this work, the authors employed different texture models for the analysis of CT scans, in order to classify benign and malignant kidney lesions. Texture analysis is performed using features such as first-order statistics (FoS), spatial gray level co-occurrence matrix (SGLCM), Fourier power spectrum (FPS), statistical feature matrix (SFM), Law's texture energy measures (TEM), gray level difference statistics (GLDS), fractal, and neighborhood gray tone difference matrix (NGTDM). Multiple texture models were utilized to quantify the renal texture patterns, which used image texture analysis on a selected region of interest (ROI) from the renal lesions. In addition, dimensionality reduction is employed to discover the most discriminative features for categorization of benign and malignant lesions, and a unique feature vector based on correlation-based feature selection, information gain, and gain ratio is proposed. Different machine learning-based classifiers were employed to test the performance of the proposed features, out of which the random forest (RF) model outperforms all other techniques to distinguish benign from malignant tumors in terms of distinct performance evaluation metrics. The final feature set is evaluated using various machine learning classifiers, with the RF model achieving the highest performance. The proposed system is validated on a dataset of 50 subjects, achieving a classification accuracy of 95.8%, outperforming other conventional models.

Highly dynamic mechanical transitions in embryonic cell populations during Drosophila gastrulation.

During development, three-dimensional morphology arises from the balance of forces acting on cells and tissues, and their material properties. Cellular forces have been investigated, however the characterisation and specification of cell material properties remains poorly understood. Here, we characterise and spatially map in three dimensions the dynamics of the longitudinal modulus at GHz frequencies to characterise the evolving blastoderm material properties during Drosophila gastrulation utilising line-scan Brillouin microscopy. We find that blastoderm cells undergo rapid and spatially varying changes in their material properties and that these differ in cells with different fates and behaviours. We identify microtubules as potential mechano-effectors, and develop a physical model to understand the role of localised and dynamic changes in material properties during tissue folding. Our work provides the first spatio-temporal description of evolving material properties during organismal morphogenesis, and highlights the potential of Brillouin microscopy for studying the dynamic changes in cell shape and cell material properties simultaneously.

Colorimetric detection of L-Dopa via anti-etching of Au nanorods catalyzed by an MIL-88A (Fe)-TMB system.

L-Dopa (L-3,4-dihydroxyphenylalanine) is a key precursor of dopamine and is extensively used in the treatment of Parkinson's disease. Accurate and efficient monitoring of L-Dopa levels is essential for optimizing therapeutic efficacy. In this study, we developed a novel and sensitive colorimetric sensor for L-Dopa detection based on the inhibition of gold nanorod (AuNR) etching by TMB2+. The sensor utilizes the antioxidant properties of L-Dopa, which inhibit the oxidation of AuNRs induced by the oxidized product of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2. The MIL-88A (Fe) metal-organic framework (MOF) catalyzes the formation of TMB2+, which subsequently oxidizes Au0 to Au+, converting AuNRs into spherical AuNPs and causing a distinct blue shift in the plasmonic peak. However, in the presence of L-Dopa, the oxidation of TMB is suppressed, thereby preserving the shape and optical properties of AuNRs. This colorimetric method is simple, rapid, and cost-effective, and shows great promise for non-invasive L-Dopa monitoring in clinical and diagnostic applications.

Synthesis and Characterization of Modified Nanodiamonds for Use as a Potential Vaccine Adjuvant Delivery Platform for a Candidate Ricin Toxin Vaccine.

Synthesis and Characterization of Modified Nanodiamonds for Use as a Potential Vaccine Adjuvant Delivery Platform for a Candidate Ricin Toxin Vaccine.

Tactile sensation and attractiveness of hair bundles in the combing process

The tactile sensation of hair depends on its shape and mechanical properties. However, scientific analysis of hair bundles during the combing process is not a lot. This study explored hand movements and mechanical stimuli using an in-situ tactile sensing system to uncover the physical origin of tactile sensation and the attractiveness of three hair bundle types: straight, curly, and wavy. The straight hair type received the highest attractiveness score (6.9 ± 2.5), closely associated with the sensations of smoothness and slipperiness. While a higher smoothness score correlated with a smaller vertical force Fz, with a value exceeding eight at Fz < 1.2 N, a higher slippery sensation score correlated with a smaller moment Mx, with a value surpassing eight at Mx < 0.15 N m. Smooth and slippery sensations were implicated as the dominant factors of hair attractiveness. The smooth sensation arises when fingers glide through the hair during hand-combing without encountering resistance, while the slippery sensation is perceived as fingers pass through the ends of the hair with minimal force.

Detection of lamivudine using liquid-surface-enhanced Raman spectroscopy†

Antiretroviral medications such as lamivudine (LAM) are central to the treatment of HIV/AIDS. Because of the rise in the substandard production of these pharmaceuticals, new methods of quality control are required. In this study, the use of silver nanoparticles (AgNPs) for the detection and quantification of LAM at low concentrations was explored using a new method known as liquid-surface enhanced Raman spectroscopy (liquid-SERS). AgNPs (20–80% v/v) were prepared by chemical reduction and subsequently characterized by assessing their size, shape, absorbance, and molecular properties. A series of LAM samples (0–80 μg ml−1) were then spiked with AgNPs and evaluated using liquid-SERS. Subsequently, a partial least-square analysis was conducted to determine the linearity (R2), sensitivity, limit of detection (LOD) and quantification (LOQ) of selected peak ratios. The results show an improved sensitivity for the 783 cm−1 band of the drug when coupled with the 945 cm−1 band of the citrate stabilizer, which is likely facilitated by intermolecular forces such hydrogen bonding dipole–dipole forces between the functional groups. Secondly, the R2 ranged between 0.96–0.98, while the LOD and LOQ reached 1.12 to 10.49 and 3.39 to 31.77 μg ml−1 respectively. These values were found to be comparative to results reported using common techniques such as UV-vis spectroscopy and high-performance liquid chromatography. As such, it was concluded that further investigation into drug/AgNPs and liquid-SERS could provide new methods of quality control for pharmaceutical products at low concentrations, through a rapid, complementary and cost-effective photonics approach.

Aggregate pore and shape properties were more strongly correlated to soil organic carbon in large aggregates: Evidence from a long-term management-induced soil carbon gradient

Aggregate pore and shape properties were more strongly correlated to soil organic carbon in large aggregates: Evidence from a long-term management-induced soil carbon gradient

Perovskite Quantum Dots: Fabrication, Degradation, and Enhanced Performance Across Solar Cells, Optoelectronics, and Quantum Technologies

ABSTRACTMetal halide perovskites exhibit excellent absorption properties, high carrier mobility, and remarkable charge transfer ability, showcasing significant potential as light harvesters in new‐generation photovoltaic and optoelectronic technologies. Their development has seen unprecedented growth since their discovery. Similar to metal halide perovskite developments, perovskite quantum dots (PQDs) have demonstrated significant versatility in terms of shape, dimension, bandgap, and optical properties, making them suitable for the development of optoelectronic devices. This review discusses various fabrication methods of PQDs, delves into their degradation mechanisms, and explores strategies for enhancing their performance with their applications in a variety of technological fields. Their elevated surface‐to‐volume ratio highlights their importance in increasing solar cell efficiency. PQDs are also essential for increasing the performance of perovskite solar cells, photodetectors, and light‐emitting diodes, which makes them indispensable for solid‐state lighting applications. PQDs' unique optoelectronic characteristics make them suitable for sophisticated sensing applications, giving them greater capabilities in this field. Furthermore, PQDs' resistive switching behavior makes them a good fit for applications in memory devices. PQDs' vast potential also encompasses the fields of quantum optics and communication, especially for uses like nanolasers and polarized light detectors. Even though stability and environmental concerns remain major obstacles, research efforts are being made to actively address these issues, enabling PQDs to obtain their full potential in device applications. Simply put, understanding PQDs' real potential lies in overcoming obstacles and utilizing their inherent qualities.

A Review on the Classification, Characterisation, Synthesis of Nanoparticles and Their Application

Nanoparticles (NPs) have become a central focus in scientific and technological research due to their exceptional physical, chemical, and biological properties. With sizes ranging typically from 1 to 100 nanometers, these particles possess a high surface area-to-volume ratio, quantum confinement effects, and tunable surface functionalities, enabling their application in a wide variety of disciplines. Their unique characteristics have made them invaluable in medicine, environmental science, energy storage and conversion, catalysis, and advanced material design. This review provides a detailed examination of the classification, synthesis methods, characterization techniques, and diverse applications of nanoparticles. Classification is discussed based on origin (natural or engineered), composition (metallic, metal oxide, carbon-based, polymeric, and composite), and morphology (spherical, rod-like, tubular). Various synthesis routes are explored, categorized broadly into top-down and bottom-up approaches. These include physical methods like mechanical milling and laser ablation, chemical methods such as sol-gel and hydrothermal techniques, and biological or green synthesis that uses plant extracts or microorganisms to produce eco-friendly nanoparticles. A wide range of characterization techniques electron microscopy (SEM, TEM), spectroscopy (UV–Vis, FTIR, XRD), and surface area analysis (BET) are essential for evaluating the size, shape, structure, composition, and surface properties of nanoparticles. The paper also highlights key applications of nanoparticles in targeted drug delivery, cancer treatment, environmental remediation (water purification and pollutant degradation), energy devices (solar cells and batteries), and industrial processes. While the potential of nanoparticles is vast, several challenges persist, including toxicity, environmental impact, cost-effective synthesis, and regulatory issues. The review concludes by emphasizing the need for sustainable synthesis methods, improved characterization standards, and interdisciplinary research to fully harness the promise of nanotechnology for societal and industrial advancement.

Stochastic orders and shape properties for a new distorted proportional odds model

Building on recent developments in models focused on the shape properties of odds ratios, this paper introduces two new models that expand the class of available distributions while preserving specific shape characteristics of an underlying baseline distribution. The first model offers enhanced control over odds and log-odds functions, facilitating adjustments to skewness, tail behaviour, and hazard rates. The second model, broadening flexibility on the shape of odds functions, describes these as quantile distortions. This approach leads to an enlarged log-logistic family capable of capturing these quantile transformations and diverse hazard behaviours, including non-monotonic and bathtub-shaped rates. Central to our study are the shape relations described through stochastic orders; we establish conditions that ensure stochastic ordering both within each family and across models under various ordering concepts, such as hazard rate, likelihood ratio, and convex transform orders.

Influence of Ionizing Radiation on Bio-synthesis of Noble Metal SF-AgNPs: Their Applications

Objectives: The aim of this study was to explore the rapid and extracellular synthesis of silver nanoparticles (AgNPs) using aqueous Bombyx Mori Silk fibroin (SF) solution, facilitated by UV irradiation. The study seeks to assess the stability, size, shape, and other key properties of the synthesized silver nanoparticles. Methods: Silver nanoparticles were synthesized by exposing the silk fibroin solution to UV radiation characterization of the synthesized AgNPs was carried out using various techniques, including UV-Vis spectroscopy to confirm nanoparticle formation, X-ray diffraction (XRD) for structural analysis, transmission electron microscopy (TEM) for morphological observation, Fourier transform infrared spectroscopy (FT-IR) to identify protein functional groups, and thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) to assess thermal stability. Findings: UV-Vis spectra confirmed the formation of silver nanoparticles, with an increase in absorption corresponding to longer irradiation times. XRD analysis revealed a face centered cubic structure, indicating metallic silver nanoparticles. TEM images showed the nanoparticles to be spherical or nearly spherical in shape. FT-IR spectra indicated the involvement of silk fibroin proteins in the synthesis process. The TGA and DSC results demonstrated enhanced stability of the SF/AgNPs composites compared to bulk materials. Novelty: This study presents a simple, eco-friendly biosynthesis approach for silver nanoparticles using Bombyx mori silk fibroin and UV irradiation. The method provides a controlled synthesis process, allowing for the adjustment of particle size and shape through irradiation parameters, offering an alternative to more traditional physical and chemical methods in nanoparticle synthesis. The stability and minimal chemical reactivity of the synthesized nanoparticles enhance their potential applications in various fields, including medicine, environmental protection, and nanotechnology. Keywords: Bombyx mori silk, Silver nanoparticles, UV-Vis, TEM, TGA, DSC

Interfacing B-DNA and DNA Mimic Foldamers.

A linker unit was designed and synthesized that can serve both as a hairpin turn in a DNA duplex and anchor point for an aromatic helical foldamer mimicking the shape and surface properties of B-DNA. Methods were developed to synthesize natural/non-natural chimeric molecules combining foldamer and DNA segments. The ability of the linker to position the foldamer helix and the duplex DNA so that their rims and grooves are in register, despite their completely different chemical nature, was demonstrated using single crystal X-ray diffraction, circular dichroism and molecular models. Bio-layer interferometry confirmed that artificial hairpin DNA duplexes keep their ability to bind to DNA binding proteins. The chimeric molecules may pave the way to competitive inhibitors of protein-DNA interactions involving sequence-selective DNA-binding proteins.

Eine Schnittstelle zwischen B‐DNA und DNA‐Mimikry‐Foldameren

KurzzusammenfassungEs wurde eine Linkereinheit entworfen und synthetisiert, die sowohl als Haarnadelturn in einem DNA‐Duplex als auch als Ankerpunkt für ein aromatisches helikales Foldamer dienen kann, das die Form und Oberflächeneigenschaften von B‐DNA nachahmt. Es wurden Methoden zur Synthese natürlicher und nicht natürlicher chimärer Moleküle entwickelt, die Foldamer und DNA‐Segmente kombinieren. Die Fähigkeit des Linkers, die Helix des Foldamers und die Duplex‐DNA so zu positionieren, dass ihre Ränder und Furchen trotz ihrer völlig unterschiedlichen chemischen Beschaffenheit zueinander passen, wurde mit Hilfe von Einkristall‐Röntgenbeugung, Zirkulardichroismus und Molekülmodellen nachgewiesen. Bio‐Layer‐Interferometrie bestätigte, dass die künstlichen Haarnadel‐DNA‐Duplexe ihre Fähigkeit zur Bindung an DNA‐bindende Proteine behalten. Die chimären Moleküle könnten den Weg zu kompetitiven Inhibitoren von Protein‐DNA‐Wechselwirkungen ebnen, an denen sequenzselektive DNA‐bindende Proteine beteiligt sind.

The Interface Effect of Electrospun Fiber Promotes Wound Healing.

Chronic wounds pose a major healthcare challenge, involving complex endogenous biochemical processes and cellular immune responses from trauma. Electrospinning is a simple, cost-efficient technique to produce nanofibers with adjustable size, shape, and chemical properties. These nanofibers can mimic the structure and function of the natural extracellular matrix (ECM), creating a physiological microenvironment that aids wound healing and hemostasis. This review first analyzes the pathophysiological features of diabetic wounds. It then explores the principles, methods, and material processing of electrospinning, focusing on its wound repair mechanisms. The application of tissue engineering in wound repair is discussed, along with significant advancements in electrospinning technology over the past 10 years. Particular emphasis is placed on multifunctional electrospun materials for diabetic wound healing. Finally, the review forecasts the technology's future development and potential in wound care, aiming to offer a comprehensive understanding of electrospinning's role in chronic wound treatment.

Against Character Constraints

ABSTRACT This paper defends the following principle: For any visually perceptible set of objects and any visual phenomenal character, there could be a veridical perception of exactly those objects with that character. This principle is rejected by almost all contemporary theories of perception, yet rarely addressed directly. Many have taken the apparent inconceivability of a certain sort of ‘shape inversion'—as compared to the more plausible, frequently discussed ‘colour inversion’—as evidence that the spatial characters of our perceptions are uniquely suited to and/or revelatory of the structure of their objects, such that alleged perceptions of those objects that differed radically in spatial character could not be veridical. I argue that these conclusions are unjustified: I claim that the difficulty involved in constructing coherent ‘shape inversion’ scenarios is attributable to the complex relations among visual and tactile shape experiences, as opposed to relations between shape experiences and worldly shape properties.

Ultrasharp, Cavity Enhanced, Broadly Tunable Infrared Detection Using Colloidal Quantum Dots.

After the success of semiconductor nanocrystals as light sources for displays in the visible range, the infrared range now offers a complementary playground. Applications requiring chemical contrast in images and applications to LIDAR technology incentivize the development of devices with narrow spectral responses. However, the solutions that rely on introducing notch filters still suffer from imperfect transmission at the wavelength of interest in a spectral range where their detection is already difficult. Here, we explore the integration of a short-wave infrared detector directly into a dielectric microcavity. Our approach simultaneously achieves ultranarrow absorption lines below 30 cm-1 at a telecom wavelength, together with a broadband, continuous, postfabrication spectral tunability over 1200 cm-1. By taking advantage of the field magnification inside the cavity, we demonstrate that the spectral shaping properties can be obtained while maintaining performances on par with an uncoupled device, stressing the benefit of this method compared to filter-only approaches.

γ-Radiation-assisted molecular template route: a new hybrid path for facile synthesis of size-dependent optical properties of ZnS quantum dots

ZnS is a benign and multi-utility semiconductor with absorption in the UV–vis region of the energy spectrum. Nevertheless, the synthesis of ZnS quantum dots (QDs) with tunable optical properties and a reasonable photoluminescent quantum yield (PLQY) adopting a new hybrid method is highly recognized. The present study involves the simple synthesis of self-capped wurtzite ZnS QDs employing a hybrid method comprising a single-source molecular precursor (SSMP), 2-(dimethylamino)ethanethiolate of zinc(II), and γ-radiation followed by elucidation of the formation mechanism of self-capped ZnS QDs. Here, the SSMP has been γ-irradiated in a solution to yield ZnS QDs of varying size at different radiation doses. The crystal structure, elemental composition, shape and optical properties of pristine self-capped ZnS QDs were assessed by powder X-ray diffraction, energy dispersive X-ray spectroscopy, electron microscopy, UV–vis, photoluminescence and diffused reflectance spectroscopy, respectively. The size-tailored emission maximum and optical band gaps were tweaked to a tune of 417–537 nm and 4.17–4.23 eV by altering the γ-radiation dose with PLQYs realized in the range of 10–24%. Lifetimes of these samples are in the range of 1.69–2.68 and 6.82–34.88 ns for the fast- and slow-decaying components, respectively.

Crown ether-functionalized metal organic framework biomimetic nanochannels membrane for efficient Tl+ ion transport and Tl+/Li+ sieving.

Crown ether-functionalized metal organic framework biomimetic nanochannels membrane for efficient Tl+ ion transport and Tl+/Li+ sieving.

Optimization strategies of filler morphology and spatial design in polymer nanocomposites for next-generation energy storage

Polymer composites are emerging as critical materials for advanced dielectric energy storage due to their excellent flexibility, high dielectric constant ([Formula: see text]), and superior pressure resistance. They are ideal for next-generation devices requiring high power density and fast charge/discharge cycles. Strategic selection of fillers — optimizing their composition, structure, and surface properties within the polymer matrix — significantly enhances composite performance. This review examines recent advances in dielectric polymer composites, emphasizing the critical challenge of filler dispersion, which directly impacts homogeneity and overall performance. We categorize nanofillers based on size, shape, and material properties and discuss surface modification strategies to mitigate dielectric mismatches between fillers and matrices. We also explore the design of transition layers around nanofillers to improve filler-matrix interactions and enhance dielectric performance. Additionally, the spatial architecture of multilayer films is examined, demonstrating how layer arrangement optimizes electric field distribution and breakdown strength. Finally, we address critical challenges in developing high-performance dielectric polymer composites for capacitors and outline future research directions to improve recoverable energy density, stability, and scalability for commercial applications. This review offers valuable insights for researchers and engineers working to advance dielectric energy storage materials.