Unique Shape Research Articles

Advances and Challenges of Microneedle Assisted Drug Delivery for Biomedicals Applications: A Review.

Microneedles have been explored as a novel way of delivering active ingredients into the skin. They have various advantages, such as quick and efficient drug delivery, mechanical stability, minimal pain, variable capacity and easy use. Microneedles are enabled for the delivery of vaccine, peptides, medicinal components and in cosmetology, which couldn't go unnoticed. The novel approaches in the transdermal drug delivery system have increased the efficiency of drug delivery into the skin by crossing the skin barriers. This platform has a wide range of applications and can also be used to deliver non-transdermal biomedicals. The variety in the design of microneedles has demanded similar diversity in their methods of fabrication; micro molding and drawing lithography may be useful methods. There are different types of polymers and materials for the fabrication of microneedles. Several synthetic and natural materials are used in the fabrication of microneedles. Unique shapes, materials, and mechanical properties are modified for organ-specific applications in microneedle engineering. In this review, we discuss several factors and their roles to cross the biological barriers for transdermal drug delivery in various sites, such as in ocular, vascular, oral, and mucosal tissue. Additionally, this article highlights the future scope of transdermal drug delivery systems through microneedles.

Ultrathin visible-light OCT endomicroscopy for in vivo ultrahigh-resolution neuroimaging in deep brain

Deep-brain neuroimaging, a task that demands high-resolution imaging techniques for visualizing intricate brain structures, assessing deep-seated disease histopathology, and offering real-time intervention guidance, is challenged by the resolution-depth trade-off of current methods. We propose an optical coherence tomography (OCT) endomicroscopy device for high-resolution in vivo imaging of deep brain microstructures and histopathology. A unique liquid shaping technique enables the direct fabrication of a microlens on the fiber tip of the imaging probe, optimizing imaging performance parameters, such as longitudinal focal shift, focused spot size, and working distance. In addition, a broadband visible-light source enhances axial resolution and OCT imaging contrast. As a result, the first monolithic visible-light OCT (vis-OCT) endomicroscope, with a submillimeter outer diameter (∼0.4 mm), is presented, achieving an ultrahigh resolution of 1.4 μm axial × 4.5 μm transverse in air. This compact probe allows minimally invasive in vivo deep-brain imaging in mice at a depth of 7.2 mm. Key regions in the mouse deep brain, such as the isocortex, corpus callosum, and caudate putamen, were successfully identified using our vis-OCT endomicroscope. In addition, we examined the myeloarchitectures and cytoarchitectures in the isocortex. Our findings demonstrate that the vis-OCT endomicroscope offers enhanced visualization of myelinated axon fibers and nerve fiber bundles compared to its 800 nm counterpart. This vis-OCT endomicroscope, overcoming resolution and imaging depth limitations of conventional methods, offers a novel tool for minimally invasive, ultrahigh-resolution in vivo deep brain neuroimaging.

High-efficiency wide-angle anomalous refraction with acoustic metagrating

Abstract The emergent metagrating, with its unique and flexible beam shaping capabilities, offers new paths to efficient modulation of acoustic waves. In this work, an acoustic metagrating is demonstrated for high-efficiency and wide-angle anomalous refraction. It is shown that the normal reflection and transmission can be totally suppressed by properly modulating the amplitude and phase characteristics of the metagrating supercells for high-efficiency anomalous refraction. The anomalous refraction behavior is achieved in the wide range of incident angles from 28° to 78°, and the efficiency of -1st order diffraction is higher than 90% by finely designing the metagrating structure. The anomalous refraction behaviors are verified experimentally at incidence angle of 28°, 45° and 78°, respectively. The demonstrated metagrating is anticipated to possess efficient wide-angle composite wavefront engineering applications in such fields as communications.

Population Structure and Selection Signatures in Chinese Indigenous Zhaotong Pigs Revealed by Whole-Genome Resequencing

Zhaotong pig (ZTP) is a Chinese indigenous pig breed in Yunnan Province, known for its unique body shape and appearance, good meat quality, strong foraging ability, and adaptability. However, there is still a lack of research on its genome. In order to investigate the genetic diversity, population structure, and selection signatures of the breed, we conducted a comprehensive analysis by resequencing on 30 ZTPs and comparing them with genomic data from 10 Asian wild boars (AWBs). A total of 45,514,452 autosomal SNPs were detected in the 40 pigs, and 23,649,650 SNPs were retained for further analysis after filtering. The HE, HO, PN, MAF, π, and Fis values were calculated to evaluate the genetic diversity, and the results showed that ZTPs had higher genetic diversity and lower inbreeding coefficient compared with AWBs. Population structure was analyzed using NJ tree, PCA, ADMIXTURE, and LD methods. It was found that ZTPs were population independent of AWBs and had a lower LD decay compared to AWBs. Moreover, the results of the IBS genetic distance and G matrix showed that most of the individuals had large genetic distances and distant genetic relationships in ZTPs. Selection signatures were detected between ZTPs and AWBs by using two methods, FST and π ratio. Totals of 1104 selected regions and 275 candidate genes were identified. Finally, functional enrichment analysis identified some annotated genes that might affect fat deposition (NPY1R, NPY5R, and NMU), reproduction (COL3A1, COL5A2, GLRB, TAC3, and MAP3K12), growth (STAT6 and SQOR), tooth development (AMBN, ENAM, and ODAM), and immune response (MBL2, IL1A, and DNAJA3). Our results will provide a valuable basis for the future effective protection, breeding, and utilization of ZTPs.

Histopathological Correlation Between High Endothelial Venule Neogenesis and the Tumor Microenvironment in Lung Adenocarcinoma.

The dynamic interplay between cancer cells and the microenvironment involves a wide range of intricate relationships that evolve during different stages of tumor progression. Recent attention has focused on high endothelial venules (HEVs), specialized endothelial cells in tumors with a unique cuboidal shape similar to those in lymph nodes. Previous animal studies have shown that normalization of tumor angiogenesis through anti-VEGFR2 therapy promotes HEV formation. However, few reports exist regarding the relationship between HEVs and preexisting blood vessels or interstitial fibers. In this study, we histologically examined whether tumor vascular structure correlates with HEV neogenesis. A total of 109 patients with pathological stage I lung adenocarcinoma who had undergone curative lung resection at our Institute between 2012 and 2016 were included. HEVs were identified by anti-peripheral node addressin (PNAd) staining. Immunostaining and Elastica-Masson-Goldner staining were performed on tumor sections and quantified. PNAd-positive cells were identified in 102 (93.6%) patients. Nearly all PNAd-positive cells were located within or near immune cell clusters. We investigated the correlation between microvessel structures or interstitial fibers and the number/density of PNAd-positive vessels, but no significant correlation was found. Since PNAd-positive cells were concentrated in immune cell aggregates, we focused our analysis specifically on these regions. Immune cell aggregates with abundant PNAd-positive vessels had a greater microvessel density along with by rich collagen fiber production, and displayed a more mature morphological phenotype of HEVs. The generation of PNAd-positive cells in tumors is governed by an angiogenetic mechanism distinct from that of broader tumor microenvironment. Furthermore, the accumulation of immune cells is associated with increased HEV maturation.

Assessing aortic morphology post aortic valve replacement using unsupervised hierarchical clustering and statistical shape modelling

Abstract Introduction There are different surgical procedures used to treat aortic valve disease such as aortic valve replacement (AVR), the Ozaki procedure, the Ross procedure, and the valve-sparing procedure. There may be postoperative side effects associated with aortic morphology. Computational analyses that assess morphology are thus necessary in such scenario. Statistical shape modelling is used to assess three-dimensional morphology, discover unique shape features, create mean shapes, and create shape modes that display morphological variability. Hierarchical cluster analysis is a machine learning method used to classify a population into subgroups. Both of these statistical methods were applied to aortic valve replacement patients to evaluate morphological variability after aortic valve replacement (AVR) surgery. Purpose The purpose of this study is to assess the aortic morphology of AVR patients, identify morphological differences between different surgical procedures, identify subgroups postoperatively using statistical shape modelling and hierarchical cluster analysis, and assessing possible correlations between the resultant clusters and function i.e. ejection fraction. Methods Computed tomography and cardiac magnetic resonance images were used to reconstruct aortas into 3D models using segmentation and 3D reconstruction software. For each patient, two models were created (i.e. ascending aorta only and aorta including the arch and the descending aorta). N=35 patients were included in the study. Statistical shape analysis was run to create templates and shape modes. Statistical environment and language software was used to run hierarchical cluster analysis. Results Overall, the hierarchical cluster analysis did not classify the aortas based on type of surgery, but most patients in the Ross group demonstrated morphological differences from the other surgical groups and many of the aortas belonging to the Ross group were clustered together in both clustering analyses. No significant differences between clusters were seen (p=0.47 for ascending, p=0.19 for whole aorta). No correlation was found between clusters and ejection fraction (p=0.75, r2<0.01), possibly indicating that post-AVR aortic morphology in this sample does not reflect overt functional changes. Conclusion Both statistical shape modelling and hierarchical cluster analyses were successful in assessing morphological variability and identifying subgroups in this population. This framework could therefore be extended to larger samples to inform on surgical decision-making allowing surgeons to choose the appropriate surgery for the patient or design prosthetic valves that are more customised to the patient’s anatomy.Cluster-Ejection Fraction Correlation

Robust self-healing capacity and high mechanical properties of castor oil-based waterborne polyurethane based on “kill two birds with one stone” strategy

Achieving ideal combination of high self-healing efficiency and good mechanical properties is of significance for the breakthrough in the application of self-healing materials. Herein, the functionalized castor oil-based waterborne polyurethane (DA-CWPU) was constructed based on “killing two birds with one stone” molecular design strategy with the addition of self-healing monomer D-A adduct. Firstly, D-A adduct containing flexible D-A bonds and rigid ring structure was prepared by D-A reaction with furfuryl alcohol (FA) and bismaleimide (BMI) as raw materials, which could not only effectively enhanced the self-healing ability of the material, but also ensured the strong mechanical properties. Then, DA-CWPU emulsion with favourable self-healing and mechanical properties was synthesized by the polymerization of castor oil (CO), isophorone diisocyanate (IPDI) and D-A adduct. The DA-CWPU film has preferable self-healing efficiency (93 % at 100 °C for 50 min), unique shape memory effect (rehabilitate after heating at 100 °C for 45 s), good toughness (485 MJ/m3), strong tensile strength (5.96 MPa) and sufficient elongation (115 %). At the same time, the self-healing DA-CWPU film can be recycled through solution casting. The sustainable castor oil-based waterborne polyurethane can be used as finishing agents for leather products, which realizes repeatedly self-healing in case of surface damage, greatly increasing the service life of the material and mechanical properties, providing a new approach for the development of mechanically robust self-healing materials.

STEM ATTITUDE DISPARITY: THE IMPACT OF LEARNING EXPERIENCES IN VOCATIONALLY-ORIENTED POLYTECHNIC AND UNIVERSITY ON STUDENTS’ SELF-EFFICACY, EXPECTANCY-VALUE, AND CAREER INTEREST

Learning experiences are widely recognized as crucial in developing students’ attitudes towards science, technology, engineering and mathematics. Vocationally-oriented polytechnics and universities provide distinct learning experiences that may significantly influence students’ STEM self-efficacy, expectancy-value and career interest. The study explores how the unique learning experiences shape students' STEM attitudes among 487 students during their fourth semester at vocationally-oriented polytechnic and university. The S-STEM survey was adopted as the measurement instrument. The result showed that university students displayed a more favorable overall STEM attitude compared to students enrolled in vocational-oriented polytechnic. University students demonstrated greater STEM self-efficacy than polytechnic students, but no significant difference in STEM expectancy-value was detected between the two groups. From the perspective of inter-group comparison, university education consistently fostered students a heightened sense of STEM self-efficacy, expectancy-value and career interest in science, whereas vocationally-oriented polytechnic education boasted its unique strengths in cultivating robust attitudes and career interests towards science and engineering/technology. However, students in both institutions exhibited a relatively less positive attitude towards learning mathematics. The findings highlight the importance of learning experiences in shaping students' STEM attitudes and career interests. Keywords: career interest, expectancy-value, learning experiences, self-efficacy, STEM attitude

V2O5-MnO2 nanocomposites as an efficient electrode material for high-performance aqueous supercapacitors

Redox-active supercapacitors are very interesting due to their high energy density (>25 Wh kg−1 at device level) and redox charge storage mechanism. In this work, V2O5-MnO2 nanocomposites are synthesized by a scalable hydrothermal approach. MnO2 in V2O5 provides better structural stability with reasonable electrochemical performance, in which V2O5 enhances the cyclic stability and rate capabilities. The V2O5-MnO2 -based electrodes deliver a specific capacitance of 266 F g−1 at 0.5 A g−1 and are stable up to 6500 cycles with 97 % capacitance retention at 5 A g−1. The kinetic study depicts that composite electrodes have a 64 % diffusive and 36 % capacitive charge storage contribution to the overall charge storage at 1 mV s−1. In symmetric full cells, the composite materials show a wide active potential window of 2.5 V and retain 83 % capacitance after 10000 continuous GCD cycles at an applied current density of 2 A g−1. The promising charge storage performance is due to a suitable conducting matrix and the effective coating of MnO2 nanoparticles over the unique V2O5 niddle shape (two-dimensional) micro-rods.

Unsupervised Denoising in Spectral CT: Multi-Dimensional U-Net for Energy Channel Regularisation

Spectral Computed Tomography (CT) is a versatile imaging technique widely utilized in industry, medicine, and scientific research. This technique allows us to observe the energy-dependent X-ray attenuation throughout an object by using Photon Counting Detector (PCD) technology. However, a major drawback of spectral CT is the increase in noise due to a lower achievable photon count when using more energy channels. This challenge often complicates quantitative material identification, which is a major application of the technology. In this study, we investigate the Noise2Inverse image denoising approach for noise removal in spectral computed tomography. Our unsupervised deep learning-based model uses a multi-dimensional U-Net paired with a block-based training approach modified for additional energy-channel regularization. We conducted experiments using two simulated spectral CT phantoms, each with a unique shape and material composition, and a real scan of a biological sample containing a characteristic K-edge. orangeMeasuring the peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM) for the simulated data and the contrast-to-noise ratio (CNR) for the real-world data, our approach not only outperforms previously used methods—namely the unsupervised Low2High method and the total variation-constrained iterative reconstruction method—but also does not require complex parameter tuning.

Morphology of the unique egg cases of hornsharks (Heterodontiformes: Heterodontidae).

Many of the egg cases of oviparous chondrichthyans remain unknown and undescribed in the literature. Egg cases can be a useful taxonomic character for species distinction and can be a valuable indicator of a species distribution in the field. In this study, the egg cases for 9 of the 10 nominal species of Heterodontus are described and compared, and the terminology and methodology for studying them are standardized. Heterodontus egg cases are distinct and easily identifiable from other oviparous egg cases by having a unique corkscrew shape formed by a pair of lateral keels spiraling along its length. Heterodontus egg cases range between 7.5 and 14.5 cm in egg case length, 3.7 and 5.8 cm in egg case width at midportion, and have 0.75-4 complete rotations. Morphometric measurements of egg cases from the nine species were subjected to multivariate analysis, with unique characters enabling distinction between them. Egg cases can be separated into three morphotypes: the "wide keels lacking tendrils" group, the "narrow keels with tendrils" group, and the "wide keels with tendrils" group. The egg case of Heterodontus ramalheira remains unknown.

How voluntary sector experience as a unique institutional catalyst shapes general entrepreneurial alertness and intentions

How voluntary sector experience as a unique institutional catalyst shapes general entrepreneurial alertness and intentions

'Golden Ratio Yoshimura' for meta-stable and massively reconfigurable deployment.

Yoshimura origami is a classical folding pattern that has inspired many deployable structure designs. Its applications span from space exploration, kinetic architectures and soft robots to even everyday household items. However, despite its wide usage, Yoshimura has been fixated on a set of design constraints to ensure its flat foldability. Through extensive kinematic analysis and prototype tests, this study presents a new Yoshimura that intentionally defies these constraints. Remarkably, one can impart a unique meta-stability by using the Golden Ratio angle ([Formula: see text]) to define the triangular facets of a generalized Yoshimura (with [Formula: see text], where [Formula: see text] is the number of rhombi shapes along its cylindrical circumference). As a result, when its facets are strategically popped out, a 'Golden Ratio Yoshimura' boom with [Formula: see text] modules can be theoretically reconfigured into [Formula: see text] geometrically unique and load-bearing shapes. This result not only challenges the existing design norms but also opens up a new avenue to create deployable and versatile structural systems.This article is part of the theme issue 'Origami/Kirigami-inspired structures: from fundamentals to applications'.

Self‐Assembling Design Method of Stator Slots for AC Rotating Machines

To maximize the performance of rotating machines, it is essential to establish a design method with minimal arbitrariness. This paper proposes a self‐assembling method to design stator slots for alternating current (AC) rotating machines. First, we develop a line‐current approximation model of the stator winding using pulse‐width modulation technique and realize an ideal spatial magnetic flux density distribution. Subsequently, we design the realistic stator with an acceptable current density of the winding by forming unique slot shapes in a self‐assembling manner under two synthetic conditions using the developed line‐current approximation model as the starting model. The designed stator realizes a rotating magnetic field similar to the conventional design results. Additionally, we perform an analysis of motor rotation characteristics by combining the self‐assembled stator with a surface‐mounted permanent magnet rotor to determine the possibility of a higher output compared to that when using a conventional stator. The self‐assembled motor without relying on empirical rules shows a possibility of further improving the torque characteristics, thereby contributing to designing the AC rotating machines. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

Efficient ethylbenzene production from CO2 and benzene in a single-bed reactor

The selective synthesis of specific value-added aromatic hydrocarbons through CO2 hydrogenation holds significant strategic importance in mitigating energy and climate issues. However, the process of forming ethylated side chains on benzene rings is challenging, and the methods reported are often limited by multi-bed systems. Here, we show the first CO2 hydrogenation in tandem coupling with benzene alkylation to synthesize ethylbenzene over a single-bed system containing ZnFeOx and nano ZSM-5 catalysts. The results indicated that the bifunctional catalyst composed of ZnFeOx with a Zn/Fe ratio of 0.5 and nano-HZSM-5 exhibits excellent catalytic performance under optimized conditions. The benzene conversion reaches 28.0 %, ethylbenzene selectivity is 61.3 % and the conversion of CO2 is remarkably high, achieving 45.0 %. This single-bed system significantly promotes the in-situ utilization of ethylation intermediates. The introduction of zinc promoted the formation of ZnFe2O4 spinel, which increased the number of active sites due to its superior dispersibility and reducibility. Nano-HZSM-5 demonstrated outstanding ethylbenzene selectivity and catalytic stability owing to its unique shape selectivity, moderate acidity, and superior diffusion properties. This study further explores the reaction network and mechanism through GC–MS analysis and various model reactions, elucidating the formation pathways of primary products in detail. This research provides a new strategy for the controllable synthesis of ethylbenzene using CO2 as a C1 source in a single-bed system.

Tunable bandgaps in an elastic meta-plate with shape memory alloy springs

In this paper, a tunable metamaterial based on shape memory alloy springs is designed, which can achieve bandgap tuning by spring's unique shape memory effect. The variation mechanism of shear modulus and geometrical parameters of shape memory alloy springs is investigated by considering a detailed phase transition mechanism. For any specific temperatures, the energy band structure and frequency response spectrum of the metamaterial are calculated by numerical simulation. And the theoretical prediction models of bandgap boundary frequency and tuning range at different temperatures are established. The experimental test of vibration transmission of metamaterial is finally presented. The results show that (1) By varying the spring's shear modulus and height, the metamaterial exhibits excellent vibration isolation characteristics and bandgap tuning in low-frequency range of 124–226Hz. (2) The bandgap boundaries and tuning ranges can be predicted by the theoretical prediction model, which shows good agreement with both the simulation results and the experimental data. (3) By artificially designing shape memory alloy springs with larger shear modulus and wire radius, smaller helix radius and number of turns, the bandgap moves to higher frequencies. The current work can provide a reference for further engineering applications with the tunable elastic/acoustic metamaterials.

Bitcoin Price Bubbles and The Factors Driving Bitcoin Price Formation

The Bitcoin, one of the most discussed event of recent times, is the first cryptocurrency to be released. Bitcoin has the biggest market capitalization in the cryptocurrencies, and it is a decentralized payment tool that cannot be controlled by any government institution. Cryptocurrencies operate on top of a decentralized network, recording and verifying transactions using a technology called Blockchain. Many bubble price formations occurred in financial markets throughout history. Cryptocurrency markets are prone to manipulation because they are not connected to any center. This study aims to to investigate the buble formations in Bitcoin (BTC) US Dollar price for the period of 11 December 2017 - 31 July 2023, and also to determine the main financial variables affecting Bitcoin prices. ARDL Bounds test proves cointegration between Bitcoin price and dependent variables. Error Correction Model determines positive connection between BTC and Nasdaq100 index. A daily change in Nasdaq100 index leads to a 0.58% increase in BTC price. Model captures also negative relationship between Volatility Index, USD Index and BTC price. No long-term relationship emerges in the results. In the long run, unique and different variables shape BTC price formation.

Impact of the Epoch of Reionization sources on the 21-cm bispectrum

The morphology of the 21-cm signal emitted by the neutral hydrogen present in the intergalactic medium (IGM) during the Epoch of Reionization (EoR) depends both on the properties of the sources of ionizing radiation and on the underlying physical processes within the IGM. Variation in the morphology of the IGM 21-cm signal due to the different sources of the EoR is expected to have a significant impact on the 21-cm bispectrum, which is one of the crucial observable statistics that can evaluate the non-Gaussianity present in the signal and which can be estimated from radio interferometric observations of the EoR. Here we present the 21-cm bispectrum for different reionization scenarios assuming different simulated models for the sources of reionization. We also demonstrate how well the 21-cm bispectrum can distinguish between different IGM 21-cm signal morphologies, arising due to the differences in the reionization scenarios, which will help us shed light on the nature of the sources of ionizing photons. Our estimated large-scale bispectrum for all unique k-triangle shapes shows a significant difference in the magnitude and sign across different reionization scenarios. Additionally, our focused analysis of bispectrum for a few specific k-triangle shapes (e.g. squeezed-limit, linear, and shapes in the vicinity of the squeezed-limit) shows that the large scale 21-cm bispectrum can distinguish between reionization scenarios that show inside-out, outside-in and a combination of inside-out and outside-in morphologies. These results highlight the potential of using the 21-cm bispectrum for constraining different reionization scenarios.

Catalytic Mechanism of Formate Dehydrogenase: Does Rotation of Formate Provide the Impetus for Surmounting the Activation Energy Barrier?

AbstractFormate oxidation by Candida boidinii formate dehydrogenase was recently subjected to QM/MM MD simulations (Q. Guo et al., Biochemistry 55, 2016, 2760–2771). Inspection of snapshots from the reported umbrella sampling of the reactants state region provided two interesting observations. Firstly, an ester bond between formate and nicotinamide spontaneously formed and subsequently dissociated. Such an ester adduct was previously predicted to form with negligible energy barrier in gas phase but was so far not reported in QM/MM MD simulations. Secondly, two snapshots were identified as possible near‐attack conformations (NACs) from which the transition state (TS) can be reached by unhindered rotation of formate about its O─O axis. The NACs differ from each other in the direction of rotation required to attain TS. Calculation of natural orbitals for chemical valence channels indicated genesis of the new C─H bond already at the NAC stage. Both NACs feature a nonlinear C(formate)–H(formate)–C(nicotinamide) angle, approaching linearity only in the TS. We believe that due to the particular conception of the active site which profits from the unique triangular shape of the substrate, the formate ion can reach the TS more easily through this rotational movement than through parallel shift along the C─H vector, as previously assumed.

Enhancement of eye socket recognition performance using inverse histogram fusion images and the Gabor transform

AbstractThe eye socket is a cavity in the skull that encloses the eyeball and its surrounding muscles. It has unique shapes in individuals. This study proposes a new recognition method that relies on the eye socket shape and region. This method involves the utilization of an inverse histogram fusion image to generate Gabor features from the identified eye socket regions. These Gabor features are subsequently transformed into Gabor images and employed for recognition by utilizing both traditional methods and deep‐learning models. Four distinct benchmark datasets (Flickr30, BioID, Masked AT & T, and CK+) were used to evaluate the method's performance. These datasets encompass a range of perspectives, including variations in eye shape, covering, and angles. Experimental results and comparative studies indicate that the proposed method achieved a significantly () higher accuracy (average value greater than 92.18%) than that of the relevant identity recognition method and state‐of‐the‐art deep networks (average value less than 78%). We conclude that this improved generalization has significant implications for advancing the methodologies employed for identity recognition.