Degree Of Deformation Research Articles

Abstract 4135968: Radiomic features of skeletal muscle on prostate T1-Weighted MRI associated with MACE outcomes in prostate cancer patients undergoing hormonal therapy

Background: Patients with high-risk prostate cancer (PC) who undergo hormonal therapy(HT) frequently die of major adverse cardiovascular events (MACE). Skeletal muscle on abdominal T1-weighted MRI (T1W) has been shown to be associated with cardiovascular fitness. Aims: To quantify heterogeneity associated with skeletal muscle tissue composition on prostate MRI patients undergoing HT using computationally derived radiomic features and identify their association with MACE. Methods: Cohort of N=58 men diagnosed with PC who underwent a 3 Tesla pre-treatment multi-parametric MRI followed by HT and followed up for MACE events were identified. MACE is defined as a composite of cardiovascular death, atrial fibrillation, myocardial infarction, ischemic stroke, heart failure, coronary artery disease, and peripheral vascular disease. Regions of interest (ROI) of skeletal muscle, including the obturator externus, pectineus, and the adductor group of muscles, were delineated on axial T1W under the guidance of an experienced radiologist. A set of 120 radiomic features, including gray level statistics, co-occurrence, wavelet, and texture energy-based features, were extracted within the ROI which quantifies underlying subvisual texture-based heterogeneity. Radiomics associated with MACE events were identified using the Wilcoxon rank-sum test and univariate Cox-regression (p<0.05). Results: Of the N=58 patients included in this study, 18 experienced MACE. The most common MACE event was AF (8.6%). Median-time-to-MACE event was 7.3 years (6.2-8.2). 3 radiomic features (Table 1) quantifying the heterogeneity of skeletal muscle on prostate T1W were observed to be associated with MACE. Specifically, we observe that first order features have a lower response and wavelet features have a lower response in MACE patients which suggests a higher degree of local deformations and heterogeneity in skeletal tissue compared to non-MACE patients. Conclusions: Results from our study suggest that radiomics quantified texture characteristics of skeletal muscle tissue may indicate cardiovascular fitness, reflecting the likelihood of experiencing MACE following initiation of HT in PC men. Pre-treatment identification of PC patients at high risk of MACE may allow for alternative treatment options improving cardiovascular outcomes. Future studies will involve exploring larger, multi-site cohorts and machine learning modeling to determine cardiovascular risk.

Robust-DefReg: A Robust Coarse to Fine Non-rigid Point Cloud Registration Method based on Graph Convolutional Neural Networks

Abstract Point cloud registration is a critical process in computer vision and measurement science, aimed at determining transformations between corresponding sets of points for accurate spatial alignment. In particular, non-rigid registration involves estimating flexible transformations that map a source point cloud to a target point cloud, even under conditions of stretching, compression, or other complex deformations. This task becomes especially challenging when addressing measurement-specific issues like varying degrees of deformation, noise, and outliers, all of which can impact measurement accuracy and reliability.
This paper introduces Robust-DefReg, a novel method for non-rigid point cloud registration that applies graph convolutional networks (GCNNs) within a coarse-to-fine registration framework. This end-to-end pipeline harnesses global feature learning to establish robust correspondences and precise transformations, enabling high accuracy across different deformation scales and noise levels. A key contribution of Robust-DefReg is its demonstrated resilience to various challenges, such as substantial deformations, noise, and outliers, factors often underreported in existing registration literature.
In addition, we present SynBench, a comprehensive benchmark dataset specifically designed for evaluating non-rigid point cloud registration in realistic measurement scenarios. Unlike previous datasets, SynBench incorporates a range of challenges, making it a valuable tool for the fair assessment of registration methods in measurement applications. Experimental results on SynBench and additional datasets show that Robust-DefReg consistently outperforms state-of-the-art methods, offering higher registration accuracy and robustness, even with up to 45% outliers.
SynBench and the Robust-DefReg source code are publicly accessible for further research and development at https://doi.org/10.11588/data/R9IKCF and https://github.com/m-kinz/Robust-DefReg, respectively.

Microstructure Evolution of Super304H Steel Used in a Service Power Station Boiler

The microstructure and structure of a Super304H superheater steel pipe after 47,000 h were analyzed by metallographic microscope, scanning electron microscope (SEM), and EDS, and its mechanical properties were measured by hardness meter. The results show that the austenitic grains appear on the outer wall of Super304H steel pipe after service, while the SEM and metallographic microscope tests show that the outer wall particles are coarse. There is an obvious corrosion layer on the outer surface, and the thickness of the corrosion layer on the windward surface is significantly higher than that on the leeward surface. The inner surface is refined and the hardness of the material is significantly increased; the outer surface, the inner surface, and the center all grow abnormally. In this case, the room temperature tensile strength and impact performance of the rough crystal area of the outer wall of the Super304H steel pipe are reduced and fracture along the crystal. Supervision should be strengthened to eliminate the safety risks caused by the abnormal growth of the outer wall austenite grain. The results of crystal phase microscopy show that the main structure of the material still maintains the basic structure of austenitic steel, and particle aggregation mainly occurs in the sub-inner layer of the inner and outer surface. Compared with the lee surface, the middle body structure is basically the same, but whether the thickness of the corrosion layer on the inner surface or the outer surface increases, the deformation degree of the deformation layer is greater. The hardness measurement finds that the hardness of the corrosion layer is caused by the increase in Super304H steel surface stress. In case of pipe explosion accident, the highest chance of pipe explosion here should be closely observed.

Analytical solution of surrounding rock stress and plastic zone of rectangular roadway under non-uniform stress field

The shape and extent of the plastic zone can effectively reflect the degree of deformation and failure of the surrounding rock. By applying complex variable functions and the theory of elasticity, a mechanical model for the surrounding rock of a rectangular roadway is established. The analytical solution for the stress in the surrounding rock of a rectangular roadway under a non-uniform stress field is derived, and the spatial stress distribution pattern in the surrounding rock of the rectangular roadway is obtained. Furthermore, using the Mohr-Coulomb criterion, the boundary equation of the plastic zone in the surrounding rock of a rectangular roadway is derived, and the morphological characteristics of the plastic zone are obtained. The results indicate that the plastic zones on both sides of the rectangular roadway are arc-shaped. The asymmetry of the stress environment has a significant impact on the plastic zones in the roof and floor of the rectangular roadway, causing the shape of the plastic zones to resemble a “petal” pattern. The lateral pressure coefficient and the height-to-width ratio have a significant impact on the stress distribution and the morphological characteristics of the plastic zone in the surrounding rock of the rectangular roadway. By validating the computational accuracy of the analytical solution through numerical simulations and conducting an engineering applicability analysis based on a coal mine roadway, it has been demonstrated that the analytical calculation method is both rational and possesses good engineering applicability. This provides reliable theoretical guidance for the design calculations and construction planning of similar roadway projects.

Parameters of Collision and Adhesion Process Between a Rising Bubble and Quartz in Long-Chain Amine Solution and Their Correlation with Flotation

The successful adhesion of air bubbles to mineral particles is the crucial to flotation technology. This paper systematically investigates the parameters variation in the dynamic interaction process between a rising bubble and a quartz plate in long-chain amine solutions (dodecylamine, tedecylamine, and octadecylamine). The results show that the type and concentration of long-chain amine affected the collision and adhesion process between bubbles and quartz plates remarkably. The maximum rebound distance (rebound distance after the first collision) of bubbles and the stable-state liquid film thickness gradually decreases with the increase of reagent concentration. Additionally, the collision-rebound duration and induction time shorten accordingly, the surface tension of the solution decreases, the surface hydrophobicity of quartz increases, and the deformation degree and average movement velocity of bubbles decrease. With the increase in carbon chain length, the adsorption form of the amine collector and quartz surface becomes closer to vertical, and the density of water molecules decreases. The recovery of quartz particles is highest with octadecylamine systems, corresponding well with the changing trend in steady-state liquid film thickness. This research provides an effective method for in-depth analysis of the microscopic interaction mechanism between bubbles and mineral surfaces and the prediction of flotation results.

Monitoring and Analysis of Surface Deformation in the Buzhaoba Open-Pit Mine Based on SBAS-InSAR Technology

The Buzhaoba open-pit mine is an important lignite production base in Yunnan Province, China. As mining activities have continued to progress, varying degrees of deformation have occurred in different areas of the Buzhaoba open-pit mine, threatening normal coal production and mine safety. To comprehensively investigate the characteristics of surface deformation and its influencing factors at the Buzhaoba open-pit mine, this study employed the following methods: first, the SBAS-InSAR technique was used to process 86 Sentinel-1A ascending and descending orbit remote sensing images from 2020 to 2023, obtaining LOS surface deformation information for the mining area; second, leveling observation data were used to validate the accuracy of the SBAS-InSAR results, and based on the principle of two-dimensional deformation decomposition, the east–west and vertical surface deformation information of the mining area was obtained; finally, the temporal variation characteristics and influencing factors of the Buzhaoba open-pit mine were analyzed. The study results indicate that (1) the maximum LOS surface deformation rates in the ascending and descending orbits of the mining area were −42.1 mm/a and −114.0 mm/a, respectively; (2) the correlation coefficient between the SBAS-InSAR monitoring results and the leveling observation results was 0.938, confirming the reliability of the SBAS-InSAR monitoring results; (3) the maximum east–west and vertical deformation rates obtained from the two-dimensional deformation decomposition were −103.4 mm/a and −189.2 mm/a, respectively, with the surface deformation in the east–west direction being more pronounced; (4) internal factors such as stratigraphic lithology and geological structures, as well as atmospheric rainfall, have a certain degree of influence on the surface deformation of the Buzhaoba open-pit mine. Therefore, the research results of this study can provide important data support and theoretical references for safety management and disaster prevention in the mining area.

Experimental study on seismic damage of SRC-RC vertical hybrid structure

In order to analyze the seismic performance of the SRC-RC vertical hybrid structure, three substructure models were designed, and the key data of structural performance, such as hysteresis curve, skeleton curve, bearing capacity, energy dissipation of structure, residual deformation and damage degree were obtained by carrying out low cyclic loading tests. According to the tests, the plastic development at the column base was delayed because of the reinforcement of section steel, and the plastic development at beam end was much more sufficient, which benefited the beam hinge mechanism in the transition area, so that the transition area has better energy dissipation capacity and deformation capacity. Based on the more sufficient lateral displacement of beam hinge, the beams suffered bending deformation obviously, and interaction between the beams and the infilled wall was significant, which led to a more complex interface force transmission, so the bending cracks and the shearing cracks were densely distributed along the full length of the beam. Meanwhile, the reinforcement of section steel not only improved the deformation capacity of the models but also resulted in more significant damage difference in positive and negative loading. To quantitatively evaluate the damage level, a seismic damage index system was proposed, including displacement damage degree, bearing capacity damage degree and residual deformation index, which reflect the increment of deformation caused by structural damage, the deterioration of bearing capacity and the residual deformation, respectively. It is suggested that the structural failure should be defined respectively under different modes: For the strength degradation behavior mode and ductility behavior mode, structural failure should be confirmed if the load reduces to 0.90 and 0.85 times of the peak load, respectively; and for the brittle behavior mode, the frame is considered to fail when the load reaches the peak without considering the structural performance after the peak load.

Capturing forceful interaction with deformable objects using a deep learning-powered stretchable tactile array

Capturing forceful interaction with deformable objects during manipulation benefits applications like virtual reality, telemedicine, and robotics. Replicating full hand-object states with complete geometry is challenging because of the occluded object deformations. Here, we report a visual-tactile recording and tracking system for manipulation featuring a stretchable tactile glove with 1152 force-sensing channels and a visual-tactile joint learning framework to estimate dynamic hand-object states during manipulation. To overcome the strain interference caused by contact with deformable objects, an active suppression method based on symmetric response detection and adaptive calibration is proposed and achieves 97.6% accuracy in force measurement, contributing to an improvement of 45.3%. The learning framework processes the visual-tactile sequence and reconstructs hand-object states. We experiment on 24 objects from 6 categories including both deformable and rigid ones with an average reconstruction error of 1.8 cm for all sequences, demonstrating a universal ability to replicate human knowledge in manipulating objects with varying degrees of deformability.

Evaluating fracture toughness of cold sprayed IN625 coatings: Micro-scratching method

Cold spray deposition of metals and alloys has gained considerable attention due to its advanced applications across various industries. This technique offers numerous advantages, including the absence of phase changes and oxidation. However, the process presents challenges due to its inherent complexities. Plastic deformation is crucial for the successful deposition of powder particles during cold spray. Therefore, achieving an optimal level of plastic deformation is essential. Fracture toughness is one of the important properties that can help understand the degree of plastic deformation in cold-sprayed coatings. Yet, measuring fracture toughness in these coatings is challenging because most evaluation methods are destructive and require large sample sizes. This study investigates the feasibility of predicting the fracture toughness of cold-sprayed coatings. Specifically, the micro-scratching method is employed to predict the fracture toughness of cold-sprayed IN625 coatings. IN625 is selected because of its high-end applications in sectors such as nuclear, marine, and aerospace component manufacturing. In addition to evaluating fracture toughness, the deposited coatings undergo rigorous testing and characterization to establish the microstructure-process-property relationship. The scaling of frictional force and fracture toughness confirms the validity of using scratch data for fracture toughness calculations. Hence, fracture toughness of the resulting coatings was successfully evaluated.

ANCF-based modelling of rigid-flexible coupling of helicopter flexible rotor blades

Abstract A high-precision rotor structure dynamic model applicable to a variety of helicopter blade hub structures is established considering rotor blade flexible deformation. The absolute nodal coordinate method is applied to the traditional rotor blade rigid-flexible coupling dynamics model, making the new model applicable to both fully articulated rotor blades and other advanced blade hub structures. No small-volume assumptions were made in the modelling process. Both Green’s strain expression under finite deformation and the geometrical relation of elastic deformation motion based on the absolute nodal coordinate method are used to derive the blade strain energy, kinetic energy, and the external load virtual work. The rotation angle at the articulation constraint at the root of the blade coupled with the elastic deformation degrees of freedom of the blade in three independent rigid body degrees of freedom, respectively. The rotor blade rigid-flexible coupling dynamics equations were established according to the Hamilton action principle. The time-domain simulation is carried out under a free single pendulum and fixed rotational speed/fixed torque for the established flexible blade model, which verifies the validity and high accuracy of the rigid-flexible coupling articulation model of the flexible rotor blade and the blade hub.

Accounting of Deformation Heating During Upsetting of AMg6 Alloy

The AMg6 alloy, which belongs to the Al–Mg–Mn system, has high corrosion resistance in various environments, good weldability, and good mechanical properties. During analytical and experimental studies, it was established that the AMg6 alloy, when deformed in the temperature range of 130–175 °C, has high plastic properties and can withstand large degrees of deformation without destruction and crack formation. At the same time, its microstructure retains the texture of deformation, and the hardness of the alloy increases, which indicates its deformation hardening. The article presents the results of numerical and laboratory experiments on upsetting of 20 mm diameter workpieces from a heating temperature of 20, 130, 260 and 390 °C. Using numerical experiments, the dependences of deformation heating on the upsetting rate and the initial temperature of the workpiece were obtained. Deformation heating should be taken into account when choosing heating before deformation since it can be critical in terms of overburning and loss of plastic properties and corrosion resistance of finished products. The deformation behavior of the AMg6 alloy at a heating temperature of the workpiece up to 130–175 °C, revealed in this study, indicates the prospects for conducting additional research on the study of changes in the microstructure and mechanical properties of this alloy during warm deformation.

Movement behavior and morphological change of droplets on vertically crossed fibers

Droplet capture and coalescence are critical processes for enhancing emulsion separation efficiency in oily wastewater treatment. In this paper, four kinds of motion behaviors and secondary droplet formation behaviors of oil droplets on vertically crossed fibers in a water environment were investigated using high-speed camera technology. The research shows that during the droplet capture process, droplets on large-diameter horizontal fiber exhibit greater lateral spreading, and smaller vertical elongation. Increasing the diameter of horizontal fiber significantly shortens droplet capture time. The capture time on lipophilic fiber intersection of 190–420 μm is 14 ms less than that of 190–190 μm. During the droplet coalescence process, the liquid bridge on large-diameter horizontal fiber is wider, and the droplet contraction ratio is smaller. The droplet contraction ratio on fiber intersection of 190–420 μm is 0.3 smaller than that of 190–190 μm. Increasing the diameter of horizontal fiber can promote rapid fusion between droplets, but lipophobic fibers hinder the degree of fusion and deformation. Furthermore, the diameter and wettability of horizontal fibers have significant effects on the volume of secondary droplets. The volume of secondary droplets increases with the diameter of lipophilic horizontal fiber in the capture process. The volume of secondary droplets on lipophilic horizontal fiber is approximately three times larger than that on lipophobic horizontal fiber in the coalescence process. These findings contribute to understanding the details of coalescence separation and optimizing the design of fiber fillers.

High-Temperature Deformation Behaviour of UNS S32750 Super Duplex Stainless Steel (SDSS) Alloy.

In this study, the high-temperature deformation behaviour of the UNS S32750 Super Duplex Stainless Steel (SDSS) alloy was investigated by means of deformability and microstructure evolution in the (1050-1200) °C temperature (T) range. The deformability of the UNS S32750 SDSS alloy was investigated by the up-setting method using a gravity-drop hammer, with the following deformation energy/impact energy (E∗): 545.2 J, 1021.5 J, 1480.6 J, and 1905.3 J. Data referring to deformation resistance (σc') and mechanical work (A∗) as a function of deformation temperature (T) and deformation energy/impact energy (E∗) were obtained and analysed. It was shown that increasing the deformation temperature leads to an increase in the obtained deformation degree (degree of reduction in height). By analysing the rate of increase in the deformation degree as a function of the applied impact energy, it was shown that the rate of increase in the deformation degree rises with the increase in the applied impact energy. Also, it was observed that the evolution of the deformation resistance (σc') as a function of temperature (T) shows a decreasing tendency while increasing the deformation temperature for all impact energies and that the evolution of the mechanical work (A∗) as a function of temperature (T) shows a decreasing tendency while increasing the deformation temperature for all impact energies. The microstructure evolution of the UNS S32750 SDSS alloy was investigated by X-ray diffraction (XRD) and Scanning Electron Microscopy-Electron Backscatter Diffraction (SEM-EBSD) techniques. It was observed that, in all cases, the microstructure shows intensely deformed grains, strongly elongated in the rolling direction in both ferrite (δ) and austenite (γ) intensely deformed grains. The intensity of grain deformation is increasing with the increase in the applied deformation degree. Also, it was observed that increasing the deformation temperature leads to a strong increase in the weight fraction of the dynamically recrystallised (DRX) ferrite (δ) grains.

The Influence of the Degree of Tension and Compression of Copper on the Indentation Size Effect (ISE)

The present work deals with the relationship between the degree of cold plastic deformation (up to 55.3% in the neck area in the tensile test and up to 66.6% in the compression test) and the parameters of the Indentation Size Effect (ISE). The tested material consists of 97% wrought copper. The Hanemann tester (Carl Zeiss, Jena, Germany) was used to measure micro-hardness. The loads applied during the micro-hardness test were between 0.09807 N and 0.9807 N. The influence of the load on the degree of the micro-hardness and simultaneously on the ISE, expressed by the Meyer’s index n, was significant. The influence of load on the ISE parameters was also evaluated using the Meyer’s index n, the PSR method, and the Hays–Kendall approach. For the undeformed sample, the Meyer’s index was close to 2, with the increase in the degree of tensile and compressive deformation increasing its “reverse” character (n > 2).

Study the Influence of Impact on the Filled Tube of Aluminum 6082-T6 Alloy by Consideration of Temperature using FEM

In this study, a numerical analysis of the impact behavior of a hollow tube made of aluminum 6082-T6 alloy in accordance with ISO 13314-2011 was conducted using FEM. ANSYS was utilized to execute the simulation procedure utilizing the Explicit Dynamic tool. The geometry of the present study consists of a 900 mm-long tube with a diameter of 60 x 2 mm, which was designed using SpaceClaim in Ansys. The model has meshed with a sweep-type mesh utilizing local coordinates. As a result, quadratic elements were utilized to simulate every impactor effect. The convergence of the mesh was determined in accordance with the equivalent strain analysis. The scope of the inquiry is limited to the mechanical behavior and energy conservation that occurs after the impact technique. The energy that is responsible for each and every sort of energy has been recognized. Instability was observed in both the internal and kinetic energies, with the latter reaching a maximum value of three electro-megajoules. Within each of the three axes, the directional deformation of the tube has been outlined. For a period of forty millimeters, the parallel axis of the impactor has undergone the greatest degree of maximum deformation that it has ever encountered. The equivalent stress, also known as von Mises, was measured in combination with the length of the tube, and it was discovered that it reached its highest point at 450 millimeters at the site of impact with 950 megapascal stresses.

A Pneumatic Fingerless Soft Gripper for Envelope Gripping

In grasping operations, when facing unstructured environments, the use of soft-body grippers can be a good solution to the problem of grasping objects that are inconvenient to grasp due to their fragility and irregularity. However, as the soft-body gripper is composed of soft-body material, there are problems such as insufficient gripping power. The envelope-gripping method using a fingerless structure of the soft gripper has high gripping capacity. In this paper, a new type of pneumatic, soft-body, fingerless gripper (SFLG) is proposed based on envelope-type grasping. With its rigid connectors, it forms a soft-body gripper. By changing the air pressure and structure of the internal air cavity of the fingerless gripper, the degree of deformation can be controlled to achieve grasping of the object by the soft-body gripper. Experiments show that the soft-body gripper can grasp objects of different shapes and sizes. The SFLG can grasp objects up to 6 times higher than itself, and the soft gripper of this size can grasp objects up to 13 times heavier than itself. A pneumatic, fingerless, soft gripper has been designed to grasp small and heavy or tall objects in contrast to other fingerless soft grippers.

Environmentally Friendly, Dual-Responsive Actuator Based on Nafion, Carboxylated Multiwalled Carbon Nanotubes, and Polyethylene.

As a type of smart material, flexible stimulus-responsive actuators have become a hot research topic nowadays. However, flexible actuators responding to a single stimulus source are susceptible to external perturbations, which may lead to an unstable function or even failure. Therefore, in this paper, we proposed a bilayer actuator that can be driven by both humidity and light by combining the humidity-sensitive Nafion, carboxylated multiwalled carbon nanotubes (cMWCNT) with excellent photothermal conversion properties, and commercial polyethylene (PE) tape with good humidity insensitivity and thermal expansion. First, the cMWCNT-Nafion film was prepared by a solution casting method and bonded together with PE tape to obtain a bilayer actuator. Then, the effects of the cMWCNT mass fraction and film thickness on the humidity and light response performance of the bilayer actuator were investigated. The optimal ratios of raw materials were obtained for different stimulation sources, respectively. Furthermore, the performance of the bilayer actuator with the optimal ratios was tested; it was verified that the proposed dual-responsive actuator can realize different degrees of bending deformation under different relative humidity (RH) and ultraviolet (UV) light intensity with good stability. Finally, the application potential in multiple scenarios was further verified by applying the prepared cMWCNT-Nafion/PE bilayer actuator to a smart window, crawling robot, and flexible gripper. This paper will provide a meaningful reference for the development and performance optimization of high-performance dual-responsive actuators.

Clinical characteristics of disc hemorrhages depending on their locations and glaucoma progression in myopic patients

This study aimed to investigate clinical characteristics and glaucoma progression in eyes with disc hemorrhage (DH) in the region of peripapillary atrophy (PPA) or DH in temporal region among glaucoma patients with myopia. One hundred ninety-six eyes of 196 glaucoma patients with myopia who were observed at least 4 years and had more than six visual field (VF) tests were included. Eyes with DHs located in the optic disc region at the superotemporal or inferotemporal locations were defined as typical DH. PPA area, disc ovality ratio, and disc torsion were measured. Length of γ-zone PPA, distance from disc edge to fovea, angle of scleral bending were measured using optical coherence tomography. Comparison of baseline characteristics between eyes with and without DH in PPA/DH in temporal region showed similar axial length (26.95 ± 1.60 mm; 26.82 ± 1.07 mm). γ-zone PPA was longer and angle of scleral bending was larger in eyes with DH in PPA/DH in temporal region (both p ≤ 0.001). Longer γ-zone PPA (β = 1.001; p = 0.018) and larger angle of scleral bending (β = 1.033; p = 0.008) were associated with presence of DH in PPA/DH in temporal region using logistic regression analysis. Eyes with DH in PPA/DH in temporal region had a smaller mean deviation slope of VF, a larger disc ovality ratio, a longer γ-zone PPA, and a larger PPA area when compared to those of eyes typical DH. VF progression was associated with absence of DH in PPA/DH in temporal region (p = 0.030) and larger angle of scleral bending (p = 0.019) using Cox proportional hazards model. DH in PPA/DH in temporal region was associated with stretching and deformation of sclera that may be result from myopic changes. Associated factors with VF progression was the degree of scleral deformation, not the presence of DH in PPA/DH in temporal region, showing that DH related to scleral deformation may possess clinical significance in glaucoma with myopia.

Finite element analysis of restoring length with multiple internal fixations in calcaneal body fracture

Calcaneal body fractures are often associated with varying degrees of shortening deformities. Restoring calcaneal length is crucial for the functional prognosis of the foot. Through finite element analysis, this study compared the biomechanical effects of multiple fixation schemes for calcaneal fractures. We delineated and assembled the finite element model of the Sanders type II calcaneal fracture and four internal fixation simulations (namely distraction screw, lag screw, frame locking plate, and T-shaped locking plate). Different axial forces (350, 700, and 1400 N) were then applied to simulate various postures. We then compared the inner and outer shortening distances (D1 and D2, respectively), equivalent von Mises stress, and maximum von Mises stress of the calcaneus. In the individual model, with an increase in the pressure, D1, D2, and the maximum von Mises stress gradually increased. At 1400 N, D1 and D2 for the internal fixation schemes were as follows: distraction screw (0.03 mm, 0.1 mm) < T-shaped locking plate (0.45 mm, 0.26 mm) < frame locking plate (0.50 mm, 0.26 mm) < lag screw (0.66 mm, 0.64 mm). The maximum von Mises stress values for the internal fixation methods were as follows: lag screw (491.0 MPa) < distraction screw (663.1 MPa) < frame locking plate (772.7 MPa) < T-shaped locking plate (931.8 MPa). In patients with calcaneal body fractures, the distraction screw is a potential therapeutic option for resisting calcaneal shortening.

Arrayed multi-layer piezoelectric sensor based on electrospun P(VDF-TrFE)/ZnO with enhanced piezoelectricity

Flexible pressure sensors can maintain good pressure sensing capabilities even under arbitrary degrees of deformation, which are widely used in fields such as robotic perception, physiological signal detection and wearable electronics. Currently, piezoelectric-based flexible pressure sensors face significant limitations in terms of large-area, high-sensitivity, and high-resolution pressure detection. Targeted research efforts primarily focus on enhancing the performance of piezoelectric sensors by optimizing the properties of the sensitive layer piezoelectric material and modulating device structural design. This study introduces a novel multilayer array design for flexible composite piezoelectric sensors. A high-voltage electrospinning selective deposition process is proposed to fabricate arrayed nanofiber mats. Patterned electrospun films can be automatically patterned by patterned AgNW electrodes, which allows manual alignment of patterns for subsequent stacking. Compared to sensor based on P(VDF-TrFE) prepared under the same conditions, the sensitivity of the multi-layer P(VDF-TrFE)/ZnO sensor increased from 2.82 mV/kPa to 8.30 mV/kPa, providing an effective approach for highly sensitivity wearable devices with short response time (∼5 ms).