Radial Process Research Articles

Computer-Aided Assessment of Displacement and Reduction of Distal Radius Fractures.

This study aims to investigate displacements and reductions of distal radius fractures using measurement indices based on the computer-aided three-dimensional (3D) radius shape model. Fifty-two distal radius fracture patients who underwent osteosynthesis were evaluated with pre- and post-operative distal radius 3D images. In the 3D images, three reference points, i.e., the radial styloid process (1), sigmoid notch volar, and dorsal edge (2) (3) were marked. The three-dimensional coordinates of each reference point and the barycentric coordinates of the plane connecting the three reference points were evaluated. The distance and direction moved, due to the reductions for each reference point, were (1) 12.1 ± 8.1 mm in the ulnar-palmar-distal direction, (2) 7.5 ± 4.1 mm in the ulnar-palmar-proximal direction, and (3) 8.2 ± 4.7 mm in the ulnar-palmar-distal direction relative to the preoperative position. The barycentric coordinate moved 8.4 ± 5.3 mm in the ulnar-palmar-distal direction compared to the preoperative position. This analyzing method will be helpful to understand the three-dimensional direction and the extent of displacements in distal radius fractures.

Numerical simulation of magnetic pulse radial compaction of W-Cu20 powder with a field shaper

The magnetic field in a magnetic pulse radial compaction process was analyzed in ANSYS/Multiphysical software to determine the electromagnetic force distribution on the driver tube. The node electromagnetic forces were then imported into the structure field as a boundary condition in ABAQUS/Explicit software. A modified Drucker-Prager Cap model was then established to reproduce the compaction behavior of W-Cu20 powder by writing a VUSDFLD subroutine. The Cowper-Symonds constitutive model was used to describe the deformation behavior of the driver tube, the pack tube, and the nylon terminal. Finally, the results predicted by numerical simulation were verified by experiment. The velocity, pressure variation, final distribution of relative density, and relative density uniformity during the magnetic pulse radial compaction process of W-Cu20 powder with a field shaper were predicted by the model, and the effect of field shaper on the relative density was analyzed. The results validate the numerical simulation model of magnetic pulse radial compaction. The magnetic pulse radial powder compaction with a field shaper can significantly increase the compacted compound density with the condition that the inner diameter height of the field shaper is greater than the powder filling height. Although the slit of the field shaper can cause an uneven density distribution after compaction, in the effective range of the field shaper, the density unevenness is minor under the described conditions, less than 4.1%.

A discrete bouncy particle sampler

Summary Most Markov chain Monte Carlo methods operate in discrete time and are reversible with respect to the target probability. Nevertheless, it is now understood that the use of nonreversible Markov chains can be beneficial in many contexts. In particular, the recently proposed bouncy particle sampler leverages a continuous-time and nonreversible Markov process, and empirically shows state-of-the-art performance when used to explore certain probability densities; however, its implementation typically requires the computation of local upper bounds on the gradient of the log target density. We present the discrete bouncy particle sampler, a general algorithm based on a guided random walk, a partial refreshment of direction and a delayed-rejection step. We show that the bouncy particle sampler can be understood as a scaling limit of a special case of our algorithm. In contrast to the bouncy particle sampler, implementing the discrete bouncy particle sampler only requires pointwise evaluation of the target density and its gradient. We propose extensions of the basic algorithm for situations when the exact gradient of the target density is not available. In a Gaussian setting, we establish a scaling limit for the radial process as the dimension increases to infinity. We leverage this result to obtain the theoretical efficiency of the discrete bouncy particle sampler as a function of the partial-refreshment parameter, which leads to a simple and robust tuning criterion. A further analysis in a more general setting suggests that this tuning criterion applies more generally. Theoretical and empirical efficiency curves are then compared for different targets and algorithm variations.

An algorithm for simulating Brownian increments on a sphere

This paper presents a novel formula for the transition density of the Brownian motion on a sphere of any dimension and discusses an algorithm for the simulation of the increments of the spherical Brownian motion based on this formula. The formula for the density is derived from an observation that a suitably transformed radial process (with respect to the geodesic distance) can be identified as a Wright–Fisher diffusion process. Such processes satisfy a duality (a kind of symmetry) with a certain coalescent processes and this in turn yields a spectral representation of the transition density, which can be used for exact simulation of their increments using the results of Jenkins and Spanò (2017 Ann. Appl. Probab. 27 1478–09). The symmetry then yields the algorithm for the simulation of the increments of the Brownian motion on a sphere. We analyse the algorithm numerically and show that it remains stable when the time-step parameter is not too small.

Three-dimensional evaluations of preoperative planning reproducibility for the osteosynthesis of distal radius fractures

BackgroundThree-dimensional preoperative planning was applied for the osteosynthesis of distal radius fractures. The objective of this study was to evaluate the reproducibility of three-dimensional preoperative planning for the osteosynthesis of distal radius fractures with three-dimensional reference points.MethodsSixty-three wrists of 63 distal radius fracture patients who underwent osteosynthesis with three-dimensional preoperative planning were evaluated. After taking preoperative CT scans of the injured wrists, 3D images of the distal radius were created. Fracture reduction, implants choices, and placements simulation were performed based on the 3D images. One month after the surgery, postoperative CT images were taken. The reproducibility was evaluated with preoperative plan and postoperative 3D images. The images were compared with the three-dimensional coordinates of radial styloid process, volar and dorsal edges of sigmoid notch, and the barycentric coordinates of the three reference points. The reproducibility of the preoperative plan was evaluated by the distance of the coordinates between the plan and postoperative images for the reference points. The reproducibility of radial inclination and volar tilt on three-dimensional images were evaluated by intra-class correlation coefficient (ICC).ResultsThe distances between the preoperative plan and the postoperative reduction for each reference point were (1) 2.1±1.3 mm, (2) 1.9±1.2 mm, and (3) 1.9±1.2 mm, respectively. The distance between the preoperative plan and postoperative reduction for the barycentric coordinate was 1.3±0.8 mm. ICCs were 0.54 and 0.54 for the volar tilt and radial inclination, respectively (P<0.01).ConclusionsThree-dimensional preoperative planning for the osteosynthesis of distal radius fracture was reproducible with an error of about 2 mm for each reference point and the correlations of reduction shapes were moderate. The analysis method and reference points may be helpful to understand the accuracy of reductions for the three-dimensional preoperative planning in the osteosynthesis of distal radius fractures.Trial registrationRegistered as NCT02909647 at ClinicalTrials.gov

Anatomical Assessment of Cephalic Vein and Superficial Branch of Radial Nerve Using High-Resolution Ultrasound Imaging

Introduction The superficial branch of the radial nerve (SBRN) has a risk of nerve injury during cephalic vein (CV) cannulation. Due to the lack of imaging study regarding SBRN and CV relationship, we analyzed the anatomical relationship between the SBRN and the CV using ultrasound (US) imaging.Materials and Methods In total, 82 upper limbs of 41 healthy volunteers were analyzed. The SBRN and CV were identified at the following three points in the elbow extension and pronation position: at the radial styloid process (point 1), 5 cm proximal to point 1 (point 2), and 10 cm proximal to point 1 (point 3).Results The distance between the SBRN and CV was 1.1 ± 1.0 mm at point 1, 1.3 ± 1.3 mm at point 2, and 2.1 ± 1.6 mm at point 3. The depth of the SBRN from the surface of the skin was 2.7 ± 0.9 mm at point 1, 3.5 ± 1.1 mm at point 2, and 5.5 ± 1.9 mm at point 3. The percentage of the SBRN that ran beneath the CV was 17.5%, 53.5%, and 92.4% at points 1, 2, and 3, respectively.Conclusion Ultrasonography can reveal the anatomical relationship between the SBRN and CV.

Morphometric Study of Distal End of Human Dry Radii

Introduction: Radius is the lateral bone of forearm. Important parameters of its distal end include angle of radial inclination, palmar tilt, and length of radial styloid process. Morphometry of the distal end of radius is important in various clinical orthopaedic procedures such as reduction of distal radius fractures, design of distal radius prosthesis, and kinematics of the wrist joint. The aim of this study is to determine the angle of radial inclination, palmar tilt, length of styloid process, oblique width, transverse and anteroposterior diameter of distal end of human dry radii in Nepalese population.&#x0D; Methods: This is a descriptive cross-sectional study conducted in the dissection hall of Department of Human Anatomy, Nepalese Army Institute of Health Sciences, Sanobhyrang, Kathmandu, Nepal from October 2019 to November 2019 after obtaining ethical approval. Total 76 human dry radii were included in the study by convenience sampling method. Angle of radial inclination, palmar tilt, length of styloid process, oblique width, transverse and anteroposterior diameter of distal end of human dry radii were studied. Data was collected and analysed by SPSS version 24.&#x0D; Results: Mean length of styloid process was 1.09 cm. Mean anteroposterior and transverse diameter of distal end of radius was 1.88 cm and 2.85 cm respectively. Mean oblique width of distal radius was 2.82 cm. The mean palmar tilt and angle of inclination of radius were 9.72 and 23.62 degree respectively. &#x0D; Conclusions: This study provides the reference data for the anatomical alignment while treating the injuries of the distal end of radius in Nepalese population.

Relationship between phenology of vegetation canopy and phenology of tree cambium in Helan Mountains, China.

Based on 98 Chinese pine (Pinus tabuliformis) tree-ring width data, normalized diffe-rence vegetation index (NDVI) data and land cover data in the Helan Mountains, we used VS-oscilloscope model to simulate the radial growth process of Chinese pine and to examine the relationship between vegetation canopy phenology and tree cambium phenology. Results showed that the end of season (EOS) of the vegetation canopy was significantly correlated with the EOS of the Chinese pine cambium. Such correlation was stronger than that between grassland and cambium. The start of season (SOS) and EOS of Chinese pine were related to the averaged minimum temperature in May-June and August-September, respectively. When the average minimum temperature in May-June increased by 1 ℃, SOS would be advanced by 4.3 days. The averaged minimum temperature in August-September increased by 1 ℃, EOS would be delayed by 2.6 days. The correlation between the phenology of vegetation canopy and the phenology of the cambium in Chinese pine differed among vegetation types. Simulating tree growth dynamics only through a tree-ring physiology model might lead to biased results. Using remote sensing monitoring data to combine canopy development and cambium growth would help to more accurately understand tree growth dynamics.

Frequency of De-Quervain Syndrome in Mobile Users Among Undergraduate Students of Allied Health Sciences Peshawar

Background: Repetitive strain injuries are more common in mobile phone users due to repetitive use of phone for mobile texting and games. De Quervain syndrome is as a painful complain of the wrist as stenosing tenosynovitis involving abductors of thumb at radial styloid process. The inflammation of first dorsal compartment of wrist triggers pain in De Quervain syndrome. Cell phone users who are involved in repetitive activities of thumb during text messages are more prone to develop repetitive strain injuries. Objectives: To determine the frequency of De Quervain syndrome in mobile users among under graduate students of allied health sciences Peshawar. Methods: A cross-sectional study was conducted among undergraduate students in different institutes of allied health sciences Peshawar. Sample size of 384 was selected using convenient sampling technique. Data was collected through self-administered questionnaire and Universal Pain Assessment Tool was used to assess the severity of pain. Finkelstein test was performed to diagnose De Quervain’s syndrome. Data was analyzed by using SPSS version 20. Results: Mean age of the participants was 20.73±1.78 years. Out of 384 participants, 315 (82%) were male and 69 (18%) were females, with male to female ratio 4:1 respectively. Finkelstein test was positive in 223 (58.1%) participants and negative in 161 (41.9%) participants. Conclusion: The study concluded that mobile phone users are at a greater risk of developing De Quervain’s syndrome due to repetitive movement of thumb while mobile texting, playing games without taking rest in -between activities.

Analysis of a New Artificial Muscle Type Dynamic Orthosis for Wrist Joint Disease Using a Three-dimensional Motion Analyzer.

ABSTRACTObjectives:Recently, the dart-throwing motion (DTM) has attracted attention as a functional direction of wrist joint motion. Consequently, we devised a new artificial muscle-type dynamic orthosis (Dynamic Traction Splint by Artificial Muscle, DTSaM) to reproduce DTM. This study analyzed the automatic motion of the wrist joint using a three-dimensional motion analysis system to assess how closely the DTSaM replicates DTM.Methods:The DTSaM orthosis incorporates two McKibben-type rubber artificial muscles, and measurements were performed using image analysis software and a three-dimensional motion analysis system. The wrist radial angle (WRA) was defined as the angle between the line connecting the head of the index finger metacarpal to the radial styloid process and the line connecting the radial styloid process to the lateral epicondyle of the humerus. WRAs were investigated from 60° of palmar flexion to 60° of dorsiflexion.Results:For dorsiflexion, comparisons of radial deviation and wrist ulnar angle (WUA) between the motion obtained using the DTSaM orthosis and active DTM showed a significant difference (P <0.05) at 30° and 60°, respectively. For palmar flexion, the same comparison showed a significant difference for both the ulnar and radial deviations (30°, P <0.05; and 60°, P <0.01, respectively). Furthermore, WUA showed a significant difference at 50° (P <0.05). Intraclass correlation coefficient analyses yielded good reliability with an average value of ≥0.8.Conclusion:The DTSaM orthosis produces a motion similar to the DTM. It is hoped that the use of the DTSaM orthosis will help to shorten the treatment period for patients with wrist disease.

A Fuzzy Radial Basis Inference Network With Grouped Signal Feature Embedding and Its Application in Multi-Source Signals Classification

A fuzzy radial basis inference network with grouped signal feature embedding (GFE-FINN) classification model is proposed for multi-source time-varying signal fusion analysis and feature knowledge embedding, which multi-channel signals are divided into several groups according to the sources, attribute, features and sensitivity of signals. Each pattern class of the grouped signal sample set is divided into several pattern subclasses which are more similar features according to the grouping index, and typical feature samples are extracted to implicitly express the category features knowledge of the grouped signal. A fuzzy radial basis process neuron (FRBPN) is defined, which is used as parametric membership functions, and the typical feature signal samples of the grouped pattern subclass are used as the kernel centers of FRBPN to realize the embedding of the diverse feature knowledge. Through the kernel transformation in FRBPN, the input signals of each group are fuzzified respectively. Fuzzy multiplication operation is used to realize the information synthesis based on the membership degree of grouped pattern subclasses and establish fuzzy reasoning and classification rules. The proposed method can realize the feature fusion based on fuzzy membership degree and the semantic representation based on fuzzy rules hierarchically. Through the learning of the sample set, fuzzy membership function, reasoning and classification rules are established adaptively. A comprehensive learning algorithm was given. An experiment was conducted using 4-groups 12-lead long ECG signals in diagnosis of difficult heart disease. The correct recognition rate reaches 87.95%, and the performance evaluation index and generalization ability are significantly improved.

Novel combined topical gel of lidocaine–verapamil–nitroglycerin can dilate the radial artery and reduce radial pain during trans-radial angioplasty

IntroductionRadial approach for coronary angioplasty is accepted by many specialists in medical centers around the world. The use of radial access is associated with fewer vascular complications and the same success rate in comparison with traditional femoral access. Radial artery spasm is one of the main concerns in this method. The small size of the radial artery and high density of alpha-1 adrenergic receptors in this artery can accelerate the spasm. The objects of this study were to evaluate whether the combined topical gel of lidocaine–verapamil–nitroglycerin could dilate the radial artery and reduce patient pain and sympathetic response during radial puncture.MethodsPatients undergoing elective trans-radial angioplasty were randomized to either placebo or therapeutic gel group in single-center, double-blind study. Placebo or therapeutic gel applied 1 cm proximal to the radial styloid process. Radial artery size was measured by ultrasound. Radial pain was reported by the visual analog scale (VAS) and the sympathetic response was assessed by changes in systolic (SBP) and diastolic blood pressure (DBP) and heart rate (HR). The incidence of spasm was defined by the radial artery spasm score.Results60 patients (30 patients in each group) participated in this study. A significant increase in the size of the radial artery was observed in the group receiving therapeutic gel compared to the placebo group (mean diameter, mm: 2.95 ± 0.48 vs. 2.54 ± 0.43, p = 0.001; area, cm2: 0.07 vs. 0.05, p = 0.001). During radial puncture, the radial pain intensity was significantly decreased in patients receiving therapeutic gel (4 (1–5) vs. 2 (1–2), p = 0.003). Radial artery spasm didn’t happen in any group.ConclusionBased on our results, Pre-procedural administration of combined topical gel of verapamil-nitroglycerin-lidocaine significantly increases the size of the radial artery and effectively reduces the radial pain during radial puncture in patients undergoing trans-radial angioplasty.

Ariadne's Thread in the Developing Cerebral Cortex: Mechanisms Enabling the Guiding Role of the Radial Glia Basal Process during Neuron Migration.

Radial neuron migration in the developing cerebral cortex is a complex journey, starting in the germinal zones and ending in the cortical plate. In mice, migratory distances can reach several hundreds of microns, or millimeters in humans. Along the migratory path, radially migrating neurons slither through cellularly dense and complex territories before they reach their final destination in the cortical plate. This task is facilitated by radial glia, the neural stem cells of the developing cortex. Indeed, radial glia have a unique bipolar morphology, enabling them to serve as guides for neuronal migration. The key guiding structure of radial glia is the basal process, which traverses the entire thickness of the developing cortex. Neurons recognize the basal process as their guide and maintain physical interactions with this structure until the end of migration. Thus, the radial glia basal process plays a key role during radial migration. In this review, we highlight the pathways enabling neuron-basal process interactions during migration, as well as the known mechanisms regulating the morphology of the radial glia basal process. Throughout, we describe how dysregulation of these interactions and of basal process morphology can have profound effects on cortical development, and therefore lead to neurodevelopmental diseases.

Mechanism and dynamics of picosecond radial breakdown of a gas-filled coaxial line

High-voltage picosecond breakdown of an atmospheric-pressure air-filled coaxial line in the radial electric field of a propagating transverse electromagnetic wave has been studied both experimentally and theoretically. On the one hand, we demonstrate that gas preionization by runaway electrons (RAEs) plays a decisive role in the breakdown development process: the breakdown delay time drastically increases in the absence of RAEs. On the other hand, it is established that, for sufficiently short pulses, the radial gap switching process does not have enough time to develop even in a situation where the RAE flow is effectively generated. Fundamental limitations on the breakdown strength of gas coaxial feeders imposed by this effect are discussed.

Selecting the Best Quantity and Variety of Surrogates for an Ensemble Model

Surrogate modeling techniques are widely used to replace the computationally expensive black-box functions in engineering. As a combination of individual surrogate models, an ensemble of surrogates is preferred due to its strong robustness. However, how to select the best quantity and variety of surrogates for an ensemble has always been a challenging task. In this work, five popular surrogate modeling techniques including polynomial response surface (PRS), radial basis functions (RBF), kriging (KRG), Gaussian process (GP) and linear shepard (SHEP) are considered as the basic surrogate models, resulting in twenty-six ensemble models by using a previously presented weights selection method. The best ensemble model is expected to be found by comparative studies on prediction accuracy and robustness. By testing eight mathematical problems and two engineering examples, we found that: (1) in general, using as many accurate surrogates as possible to construct ensemble models will improve the prediction performance and (2) ensemble models can be used as an insurance rather than offering significant improvements. Moreover, the ensemble of three surrogates PRS, RBF and KRG is preferred based on the prediction performance. The results provide engineering practitioners with guidance on the superior choice of the quantity and variety of surrogates for an ensemble.

Longitudinal analysis of pediatric distal radius alignment parameters in a cohort of serial radiographs.

Growth in pediatric patients necessitates changes to bony structures throughout the entire body to suit development. Changes in the distal radius during growth are of interest in the pediatric population due to the high incidence of fractures. The purpose of this study was to assess for trends in three radiographic measurements (height of the radial styloid process, radial inclination, ulnar variance) of the distal radius using serial radiographs in subjects aged between 6 and 14 years of age. Longitudinal radiographs from 68 healthy children (n = 34 males, 34 females) with a minimal of three annual radiographs between 6 and 14 years of age were analyzed. Measurements of height of the radial styloid process, radial inclination, and ulnar variance were performed in each available radiograph. Repeated measures analysis of variance (ANOVA) was performed to measure the association between alignment values and subject age. A total of 436 images in 68 subjects were analyzed, comprising a mean of 6.5 ± 2.0 radiographs per subject. Repeated measures ANOVA demonstrated that all measurement variables changed significantly with age (p < .001). Ulnar variance demonstrated the most variability with negative ulnar variance in younger children, and trends towards a more neutral ulnar variance by approximately 7 years in females and 11 years in males, while height of the radial styloid process and radial inclination changed relatively minimally with development. In the adolescent age range, ulnar variance, height of the radial styloid process and inclination are all relatively stable and adult parameter values can be used to judge restoration of distal radius alignment.

The microstructure, texture evolution and plasticity anisotropy of 30SiMn2MoVA high strength alloy steel tube processed by cold radial forging

Cold radial forging is an efficient and high-precision process for producing rotary parts such as axles and gun barrels, etc. 30SiMn2MoVA high strength alloy steel is a kind of fine pearlite steel usually used for moulds and barrels. This work focused on the effect of the cold radial forging on the microstructure, texture evolution and plasticity anisotropy of forged steel tube under different forging reductions. The results suggest that most banded structures that are parallel to the axial direction are developed by the radial forging process. The grains are elongated and refined after forging. The increase of dislocation density with the increase of deformation is the reason for grain refinement. Refined grains and high dislocation lead to high strength. Meanwhile, anisotropy was obvious and was exacerbated by the growth of the forging deformation. The circumferential strength and elongation are inferior to the axial. With the increasing of forging ratios, the α-fiber texture is well developed. The relationship between the volume fraction of texture and plastic strain was built. It can predict the volume fractions of the main texture components in the cold radial forged 30SiMn2MoVA steel tube. The Taylor factors of the main orientations were calculated. The {111}<011>(γ-fiber), {110}<110>, {111}<110>(α-fiber), {114}<110>, {112}<110> and {223}<110> texture components help to enhance the axial yield strength. Comparing the ratio of the axial average Taylor factor and the circumferential average Taylor factor with the yield strength ratio, it is found that yield strength anisotropy is not well predicted only taking into account the crystal texture. The effect of banded structures on the strength should also be considered.

Sequential Maximum Likelihood Estimation for the Squared Radial Ornstein-Uhlenbeck Process

In this paper, we study the properties of a sequential maximum likelihood estimator of the unknown parameter for the squared radial Ornstein-Uhlenbeck process. The estimator is proved to be closed, unbiased, normally distributed and strongly consistent. Lastly a simulation study is presented to illustrate the efficiency of the estimators.

Replicating Smart Cities: The City-to-City Learning Programme in the Replicate EC-H2020-SCC Project

This article addresses the problem of replication among smart cities in the European Commission’s Horizon 2020: Smart Cities and Communities (EC-H2020-SCC) framework programme. This article initially sets the general policy context by conducting a benchmarking about the explicit replication strategies followed by each of the 17 ongoing EC-H2020-SCC lighthouse projects. This article aims to shed light on the following research question: Why might replication not be happening among smart cities as a unidirectional, hierarchical, mechanistic, solutionist, and technocratic process? Particularly, in asking so, it focuses on the EC-H2020-SCC Replicate project by examining in depth the fieldwork action research process implemented during 2019 through a knowledge exchange webinar series with participant stakeholders from six European cities—three lighthouse cities (St. Sebastian, Florence, and Bristol) and three follower-fellow cities (Essen, Lausanne, and Nilüfer). This process resulted in a City-to-City Learning Programme that reformulated the issue of replication by experimenting an alternative and an enhanced policy approach. Thus, stemming from the evidence-based policy outcomes of the City-to-City Learning Programme, this article reveals that a replication policy approach from the social innovation lenses might be enabled as a multidirectional, radial, dynamic, iterative, and democratic learning process, overcoming the given unidirectional, hierarchical, mechanistic, solutionist, and technocratic approach.

Numerical Simulation and Parameter Study of Radial Forging of Conical Tube

The cone tube is an important part of the circuit connector, which has high requirements for its forming quality. In this paper, the cone tube is taken as the object, the finite element model is established, the radial forging process of the cone tube is simulated, the influence of process parameters such as axial feed and friction on the thickness of the cone tube is studied, and the influence law is analyzed, which has certain reference value for the analysis of the forming law of the radial forging.