Typical Shape Research Articles

Procrustes analysis of a shape of pediatric supracondylar humerus fractures

Shape of supracondylar fracture of the humeral of pediatric patients is analysed with Procrustes method. XR-images of fractures are considered both in anterio-posterior (AP) view and in a lateral (L) view. Applying Procrustes method for both views mean images are constructed and compared. Variability of shapes is quantified with a shape principal component analysis. Possibility of predictions of typical shape of humeral fracture and its variability using statistical shape analysis offers additional information on injury characteristics important in preoperative planning. Non-parametric tests (permutational and bootstrap) do not indicate statistical difference between Procrustes mean shapes in anterio-posterior and lateral projections. It is shown, however, that AP and L shapes of humeral fractures differ in their variability quantified by shape principal components.

Nonlinear dielectric response in glass formers: Restoring forces and avoided spin-glass criticality.

Experimental measurements of nonlinear dielectric response in glass formers like supercooled glycerol or propylene carbonate have been interpreted as providing evidence for a growing thermodynamic length scale when lowering temperature. A heuristic picture based on coherently flipping "superdipoles" with disordered internal structure has been argued to capture the essence of the experimentally reported behavior, pointing to the key role of effectively disordered interactions in structural glasses. We test these ideas by devising an explicit one-dimensional model of interacting spins incorporating both the spin-glass spirit of the superdipole argument and the necessary long-time decorrelation of structural disorder, encoded here in a slow dynamics of the coupling constants. The frequency-dependent third-order response of the model qualitatively reproduces the typical humped shape reported in experiments. The temperature dependence of the maximum value is also qualitatively reproduced. In contrast, the humped shape of the third-order response is not reproduced by a simple kinetically constrained spin model with noninteracting spins. To rationalize these results, we propose a two-length-scale scenario by distinguishing between the characteristic length of dynamical heterogeneities and a rigidity length that accounts for the local tendency of spins to flip coherently as a block, in the presence of interactions. We show that both length scales are identical in the kinetically constrained spin model, while they have significantly different dynamics in the model of interacting spins.

Influence of atmospheric rivers on extreme precipitation in western Ukraine

Formulation of the problem. In recent years, interest in the atmospheric river (AR) phenomenon is growing, as more and more researchers associate it with extreme precipitation. Relatively few works are devoted to the assessment of the influence of atmospheric rivers on precipitation in Eastern Europe. The purpose of the article is to assess the occurrence of atmospheric river events during extreme precipitation in the western regions of Ukraine (Lviv and Volyn regions) and to analyze the geographical features of the spatial distribution of atmospheric river bends during extreme precipitation. Methods. We used the catalog of atmospheric rivers identified according to the methodology of D. Walliser and B. Guan to analyze the occurrence of atmospheric river events on the territory of the western part of Ukraine. Also, we used the sample of days with extreme precipitation (greater than 95th percentile for each meteorological station and each month) in the Lviv and Volyn oblasts of Ukraine to match it with AR episodes. It is shown that in most cases extreme precipitation events were accompanied by the atmospheric river phenomenon detected on the territory of Ukraine or the bordering territories. Results. The typical shape of atmospheric river bends during extreme precipitation most often is arc-shaped while the typical spatial coverage stretched from North Africa through the Mediterranean Sea and Turkey to the territory of Ukraine. Less often, the form of detected AR area had the form of a meridional bend extending from the eastern part of the Mediterranean Sea towards Ukraine. However, the analysis showed that the presence of atmospheric river phenomenon is not the exceptional reason for extreme precipitation. Part of the extreme precipitation events is associated with specific synoptic situations (precipitation caused by cold fronts or occluded fronts) whereas conditions for atmospheric river detection are not fulfilled (bend size, meridional flow component, flow intensity). Atmospheric river episodes were not observed at most of the days of general sample (on average 72.36%) within the study area based on the period of 1991-2020. At the same time, precipitation events in the absence of AR were recorded on average in 32.2% of days (relative to the total number of days). In the presence of AR, precipitation was not recorded in about a third of cases. In the sample of days in the absence of AR and in the presence of AR, the proportion of precipitation of different gradations is as follows: for 10-20 mm is 2.73% and 2.64% respectively; for 20-50 mm is 1.37% and 1.63%; more than 50 mm is 0 .19% against 0.16%. In the spring, there is a certain consistency with the negative daily value of the NAO index and the AR axis orientation from the southwest to the territory of Ukraine. Thus, within 5 days before the localization of AR on the territory of Ukraine, values of the NAO index <-0.5 are noted, but the index changes in the process of the pressure field change. Based on a limited sample of extreme precipitation (94 cases), we assessed the correspondence of the precipitation rate to the area of atmospheric rivers and their features of the spatial orientation. ARs extending from the southwest (north of Africa) and the south (western part of the Mediterranean Sea) are characterized by the greatest recurrence. No regularities were found either concerning the dependence of the precipitation rate on the orientation of the AR, or concerning the dependence of the number of stations with extreme precipitation on the orientation of the AR. No linear dependence was found for the area of atmospheric rivers within both the study region and the territory of Eastern and Southeastern Europe with daily precipitation in the western regions of Ukraine.

A thermo-mechanical constitutive model for triple-shape and two-way shape memory polymers

Semicrystalline polymers often have diverse molecular configurations in response to the variation of temperature, making it easier to realize multiple or two-way shape memory effects (SMEs). In order to provide guidance for the design of relevant smart structures, it is necessary to develop corresponding constitutive models to better characterize the thermal-mechanical behavior of such shape memory polymers (SMPs). For the first time, a thermo-mechanical finite deformation constitutive model is presented to reveal the deformation mechanism of the triple-shape two-way SME of semicrystalline SMPs in our work, based on the theory of thermodynamics with internal state variables. To verify the validity of the model, the model results are compared with the test data for a typical shape memory cycle. It is found that the model can be employed to describe the non-equilibrium response of semicrystalline SMPs with two types of crystallites in the vicinity of crystallization and melting. Since the model results fit well with the test data, the effectiveness of the model in predicting the triple two-way shape memory behavior is demonstrated.

Pattern of reconnection after isolation of the pulmonary veins with a pulsed-field ablation

Abstract Background Pulsed Field Ablation (PFA) has proven is efficacy for pulmonary vein isolation (PVI) with an acute success in 99.9% of PVI and few major complications (1.6% of patients). (1) However, in redo procedures, the durability of the PVI was 63% at a median of 6 month in a study of Kueffer and al. (2) Purpose The purpose of this study is to analyze the pattern of these reconnections in the redo procedures. Methods We retrospectively analyzed the data among the patients that had a PVI with PFA in our institution between 1 October 2022 and 1 October 2023 who were referred for a recurrence of a tachyarrhythmia. Results Of 350 patients treated for PVI with PFA, 14 patients (4%) were referred for a recurrence of tachyarrhythmia. Among them, three (21%) were female and the median age was 72 years old [IQR 69-78]. The Chadvasc score was > 2 in 7 (50%) patients and the DR flash score was > 3 also in 7 (50%) patients. The patients were referred for paroxysmal AF (4/14 patients), persistent AF (5/14 patients), typical flutter (2/14 patients) or atypical flutter (3/14 patients). All patients had a high resolution 3D electro-anatomical mapping, in a median time of 7,4 months [IQR 5,1-11,8]. The median left atrium volume was 169 mL [IQR 150-180] and 66% of the pulmonary veins were isolated. Only two patients (14%) had durable PVI in all their veins. Two of the patients had a posterior box with their PVI and the box was blocked at 7 and 13 months after the PFA. The reconnections of the pulmonary veins was mainly in the anterior aspect of the right superior PV (6/19 reconnections, 32%). There were two typical shapes of reconnection, the « missing petal » and the « collar » patterns. Conclusion In a redo procedures at 7 months after a PFA, 14% of the patients had durable PVI and 66% of the veins were isolated. The reconnections were mainly in the anterior right superior PV and had often a typical « missing petal » or « collar» patterns.Percentage ReconnectionsPatterns Reconnections

A Review on the Concept of Pottali

Introduction: Pottali word were found in classics in different contexts mainly meaning the word for bundling the various herbal drugs in a piece of cloth and to apply for sedation in various diseases. Pottali is a highly potent, concise form of medicament, which depicts maximum potency in low dosage form. The peculiarity of Pottali lies in its typical shape, form and preparatory methods. Thus, reviewing the concept of Pottali is the main objective of this article. Material and Methods: Available literature related to Pottali were searched from available printed form of various text books, journals, web-based search engines source were referred for updated research data. Results: The present article gives a review on concept of different preparatory procedures, types mentioned in various classical textbooks, dosage, and mode of administration and significance of Pottali Kalpana. Pottali Kalpana was invented with a vision for convenience in transportation, administration, dose fixation, preservation and enhancement of properties. Conclusion: More researches and documentation are required to be done for analytical and clinical evaluation of Pottali Kalpana.

The spatiotemporal richness of hummingbird wing deformations.

Animals exhibit an abundant diversity of forms, and this diversity is even more evident when considering animals that can change shape on demand. The evolution of flexibility contributes to aspects of performance from propulsive efficiency to environmental navigation. It is, however, challenging to quantify and compare body parts that, by their nature, dynamically vary in shape over many time scales. Commonly, body configurations are tracked by labelled markers and quantified parametrically through conventional measures of size and shape (descriptor approach) or non-parametrically through data-driven analyses that broadly capture spatiotemporal deformation patterns (shape variable approach). We developed a weightless marker tracking technique and combined these analytic approaches to study wing morphological flexibility in hoverfeeding Anna's hummingbirds (Calypte anna). Four shape variables explained >95% of typical stroke cycle wing shape variation and were broadly correlated with specific conventional descriptors such as wing twist and area. Moreover, shape variables decomposed wing deformations into pairs of in-plane and out-of-plane components at integer multiples of the stroke frequency. This property allowed us to identify spatiotemporal deformation profiles characteristic of hoverfeeding with experimentally imposed kinematic constraints, including through shape variables explaining <10% of typical shape variation. Hoverfeeding in front of a visual barrier restricted stroke amplitude and elicited increased stroke frequencies together with in-plane and out-of-plane deformations throughout the stroke cycle. Lifting submaximal loads increased stroke amplitudes at similar stroke frequencies together with prominent in-plane deformations during the upstroke and pronation. Our study highlights how spatially and temporally distinct changes in wing shape can contribute to agile fluidic locomotion.

Effect of O2/n-C5H12 Ratio on Oxygenates Production from Plasma N-pentane Partial Oxidation

Objective: Non-thermal plasma is a promising method for producing clean fuels. This work provides a deeper understanding of the impact of O2/n-C5H12 ratio on the partial oxidation of n-pentane from both physical and chemical perspectives. Moreover, this work offers insight into improving fuel combustion efficiency and technical support for the preparation of clean fuels. Methods: An experimental system based on dielectric barrier discharge plasma was established. The discharge characteristics and product generation status of n-pentane partial oxidation were measured by changing the concentration of oxygen and n-pentane to evaluate different O2/n-C5H12 ratios. Results: Research on discharge characteristics showed that the O2/n-C5H12 ratio did not affect the discharge mode, and typical Lissajous shapes were present at different ratios. Changing the O2/n-C5H12 ratio affected the oxygen concentration, average electron energy or electron density, and background temperature. As the O2/n-C5H12 ratio increased, the conversion of the n-pentane partial oxidation reaction increased. However, changing the O2/n-C5H12 ratio did not affect the type of generated products. The oxygenates exhibited a volcano curve, and an O2/n-C5H12 ratio of 1.00 achieved the highest selectivity of 35.1%. As the O2/n-C5H12 ratio continued to increase, the selectivity of oxygenates decreased and the selectivity of CO2 increased. This was potentially due to a shift from partial oxidation toward complete oxidation, which led to the generation of secondary pollutants. Thus, higher O2/n-C5H12 ratios were not conducive to clean fuel production and environmental friendliness. Conclusion: In the partial oxidation of n-pentane, the highest clean fuel production rate was achieved when the O2/n-C5H12 ratio was 1.00. When this ratio exceeded 1.00, the reaction shifted toward complete oxidation, producing secondary pollutants. This study provides ideas for improving fuel combustion efficiency and technical support for the preparation of clean fuels.

Surface deformation of moving droplets of slurry fuels

Experimental research findings are reported on the characteristics of surface transformation of droplets of promising fuel slurries in the air, as they move at subsonic velocities typical of combustion chambers of power plants. The main components of the fuels were water, coal processing waste, and coal. Typical shapes of droplets and the duration of their deformation cycles were identified. Droplets containing more than 70% of the solid phase remained practically undeformed. The lowest relative velocities of droplets leading to their fragmentation were determined. The key characteristics of secondary droplets (their number, sizes, velocities, and surface area of liquid) were calculated on the basis of the experimental findings. These characteristics were compared with those of initial droplets. Disruption conditions in the chosen range of the gas jet pressure (P ≤ 6 bars) can only be provided for fuel slurry droplets containing less than 60% of a coal component. The effect of a group of factors on deformation characteristics was identified. These include air jet and droplet velocities, droplet sizes, temperature, concentration, and type of components and additives. Approximation equations were derived for the mathematical description of the experimental data. Using certain criteria, the conditions necessary and sufficient for the disruption of water–fuel slurries on impact with an air jet were estimated.

Modeling the deterioration of the stiffness and of the collagen fibril distribution in a discrete model of the cornea microstructure

We present a stochastic approach to model the mechanical deterioration of the reinforcing microstructure of the human cornea. The fundamental structural micro-components of the stroma, collagen and crosslinks, are assembled deterministically into an elementary trusswork cell, multiply repeated and distorted to form a three-dimensional shell with the shape of a cornea. The spatial orientation of the collagen-like elements of each cell is thus characterized stochastically with a non correlated random angle field, obeying an assigned probability density function, leading to a non-deterministic structural stiffness. It follows that the mechanical response of the model to the action of deterministic forces equivalent to the intraocular pressure is stochastic due to the random spatial orientation of collagen fibers. The deterioration of the mechanical stiffness of the collagen components is described through a scalar variable field, evolving in space and in time, representative of a progressive damage which causes heterogeneity and asymmetric behavior. The damage variable acts in two ways on the global stiffness: (i) by reducing the stiffness of the collagen components; (ii) by modifying the dispersion coefficient of the probability density function. The equilibrium equations of the damaging model are solved at discrete time steps, with a fully explicit solution scheme, by means of the stochastic finite element improved perturbation method. The results show that when the collagen fibril stiffness reduces to 10% of the healthy value, as expected in the case of the vision-impairing condition known as keratoconus, the displacement field due to intraocular pressure is significantly affected in terms of both average and variance distributions. This effect confers a typical conical shape to the cornea. In particular, the analysis shows that high values of the response variances are confined in the keratoconus area, which agrees with a high level of uncertainties due to loss of fibril organization and thickness reduction under pathologic conditions.

Sensory and physical-chemical analyzes of a gluten-free salt snack: development of a product based on oat flour enriched with chickpeas and carrots

Snacks are practical, quick-to-eat foods that are often included in snacks and small meals and have a major influence on the general population's diet. However, they are not recognized as healthy foods due to their low nutritional properties, excess fat, high calorie content and because they exclude people with celiac disease. This highlights the need to develop projects aimed at producing snacks with superior sensory and palatable characteristics. To meet this demand, a product was developed with the addition of chickpeas, carrots and oat flour, replacing the wheat flour commonly used in existing formulations. This was developed by making a vegetable paste and molding a dough compatible with the typical shapes of these foods. The results of the water activity, humidity and pH analyses showed levels very close to those of snacks sold on supermarket shelves, but the concentration of protein in the product was a major highlight (over 20%), demonstrating that a tasty, convenient product with a long shelf life can have high nutritional values. In the sensory analysis, the product stood out in terms of crunchiness, with the sum of the concepts “I loved it” and “I liked it” being 89.8%, and taste with 87.7%.

Human Infrapatellar Fat Pad Mesenchymal Stem Cell-derived Extracellular Vesicles Purified by Anion Exchange Chromatography Suppress Osteoarthritis Progression in a Mouse Model.

Human Infrapatellar Fat Pad Mesenchymal Stem Cell-derived Extracellular Vesicles Purified by Anion Exchange Chromatography Suppress Osteoarthritis Progression in a Mouse Model.

Synthesis of Cd-Cu nanoparticles supported on HOPG for use as electrocatalytic material for nitrate reduction

Bimetallic nanoparticles application has attracted great attention in the field of electrocatalysis because they can enhance the catalytic properties toward certain reactions of technological interest, such as nitrate reduction. For this purpose, Cd-Cu bimetallic nanoparticles were prepared on highly oriented pyrolytic graphite substrates by sequential electrodeposition of both metals. The process was studied by conventional electrochemical techniques, and the generated deposits were characterized by scanning electron microscopy − energy dispersive X-ray spectroscopy analysis. Initially, Cu nanoparticles were prepared by a simple potentiostatic pulse applied to the carbonaceous substrate. Scanning electron microscopy images showed high density of mainly hemispherical-shaped Cu crystals distributed preferably on step edges and surface defects of the highly oriented pyrolytic graphite electrode. Subsequently, Cd particles were prepared in the same way by immersing the Cu nanoparticles / highly oriented pyrolytic graphite modified substrate in an electrolyte solution containing Cd2+ ions, exploiting the phenomenon of underpotential deposition. It was evidenced that the existing crystals grew in size, most of them showing the typical shapes of those for Cd nanoparticles. The application of the Cd-Cu nanoparticles / highly oriented pyrolytic graphite electrode as a feasible electrocatalyst material for nitrate reduction was investigated by cyclic voltammetry for different nitrate concentrations, also considering the possibility of using this procedure as a method for the anion detection.

Dehydration-induced corrugated folding in Rhapis excelsa plant leaves

Plant leaves, whose remarkable ability for morphogenesis results in a wide range of petal and leaf shapes in response to environmental cues, have inspired scientific studies as well as the development of engineering structures and devices. Although some typical shape changes in plants and the driving force for such shape evolution have been extensively studied, there remain many poorly understood mechanisms, characteristics, and principles associated with the vast array of shape formation of plant leaves in nature. Here, we present a comprehensive study that combines experiment, theory, and numerical simulations of one such topic-the mechanics and mechanisms of corrugated leaf folding induced by differential shrinking in Rhapis excelsa. Through systematic measurements of the dehydration process in sectioned leaves, we identify a linear correlation between change in the leaf-folding angle and water loss. Building on experimental findings, we develop a generalized model that provides a scaling relationship for water loss in sectioned leaves. Furthermore, our study reveals that corrugated folding induced by dehydration in R. excelsa leaves is achieved by the deformation of a structural architecture-the "hinge" cells. Utilizing such connections among structure, morphology, environmental stimuli, and mechanics, we fabricate several biomimetic machines, including a humidity sensor and morphing devices capable of folding in response to dehydration. The mechanisms of corrugated folding in R. excelsa identified in this work provide a general understanding of the interactions between plant leaves and water. The actuation mechanisms identified in this study also provide insights into the rational design of soft machines.

Observation of broad triangular Frank-type stacking faults and characterization of stacking faults with emission wavelengths below 430 nm in 4H–SiC epitaxial layers

Frank-type stacking faults in 4H–SiC epitaxial layers were investigated using room-temperature photoluminescence mapping and high-angle annular dark-field high-resolution scanning transmission electron microscopy. Remarkably, the intrinsic Frank-type stacking fault (5,2) and intrinsic multilayer Frank-type stacking fault (4,2), which have been reported to have elongated triangular shapes to date, were found to have broader triangular shape, which was typical shape of Shockley-type stacking faults. The shaping of stacking faults could be explained based on the directions of the partial dislocations bounding the stacking faults. Formation models for the intrinsic (5,2) and (4,2) stacking faults were proposed. In addition, we observed Frank-type stacking faults (3,2,2,3) and (3,3) and Shockley-type stacking faults (3,3,3,2,3,2) and (3,2,3,3,3,2), which were not reported before. All of these stacking faults were composed with the stacking numbers 2 and 3 in the Zhdanov notation and showed very close characteristic photoluminescence emission wavelengths of 427–428 nm. Formation models for the stacking faults of (3,2,2,3), (3,3), (3,3,3,2,3,2), and (3,2,3,3,3,2) were proposed, also. Based on the proposed formation models of (4,2) and (3,3) stacking faults, formation models for the Frank-type stacking faults (4,1) and (3,2) were discussed. Finally, we pointed out that the (4,1) Frank-type stacking fault should be the intrinsic not the extrinsic fault, and the (3,2) Frank-type stacking fault is the extrinsic fault.

Numerical analysis of turbulent nitrogen-diluted hydrogen flames stabilised by star-shaped bluff bodies

In this paper, we investigate the flow and flame dynamics within a combustion chamber supplied with nitrogen-diluted hydrogen fuel and air as oxidiser. The chamber is equipped with a bluff body that serves as a flame stabiliser. We focus primarily on the influence of the bluff body shape on the formation of large and small-scale vortical structures generated at the bluff body edge. We analyse how the geometry of the bluff body alters these structures and examine the impact of resulting modifications on flame characteristics, including key features such as flame length and radial extent, temperature and species field, and completeness of the combustion process. We consider four bluff body geometries, namely a typical cylindrical shape, a star-shaped wall, and a small triangular sharp and smooth wavy structure. The research employs the Large Eddy Simulation (LES) method, providing deep insight into the complex physics of unsteady flow. In the cylindrical bluff body configuration, the key mechanism driving the fuel-oxidiser mixing process is the periodic occurrence of large toroidal vortices shed at an exit of the oxidiser duct and on the bluff body edge. They exert the flow towards and away from a recirculation zone formed above the bluff body. When its geometry is irregular, the appearance of the large vortices is suppressed, however, the wall irregularities induce small-scale flow phenomena that enhance mixing in the shear layer formed between the recirculation zone and the oxidiser stream. The mixing efficiency is largely dependent on the shape of the bluff body wall, and it turns out that seemingly small changes (sharp vs. smooth small triangular parts), which in non-reactive regimes have only a minor effect on the flow dynamics, significantly change the flame length and fuel consumption rate. Compared to the cylindrical bluff body configuration, the small triangular parts cause an axial shift of the maximum temperature downstream and slow down fuel consumption. Contrary, large triangular elements in the star-shape bluff body clearly influence the flow both in non-reactive and reactive regimes. They cause the formation of local oxidiser streams directed towards the fuel-rich mixture. Consequently, the injected fuel burns at a rate similar to that observed in the case of the cylindrical bluff body, but the combustion process occurs at an average temperature approximately 200 K lower and its fluctuations are reduced. These factors may influence the thermal reduction of NOx. On the other hand, a negative aspect is the highest level of hydrogen in the closest vicinity of the bluff body, which in practical applications may accelerate the embrittlement of its surface.

Impacting dynamics of nanodroplets on superhydrophobic surfaces decorated by a ridge

Reducing the contact time of impacting nanodroplets is of fundamental interest and importance due to its promising potential in various engineering applications, such as self-cleaning and anti-icing. In this work, nanodroplets impacting superhydrophobic surfaces decorated by a rectangular ridge are studied over a wide range of Weber number (We) and different sizes of the ridge via molecular dynamics. Six bouncing modes have been distinguished. The usage of the rectangular ridge significantly enhances the bouncing performance of nanodroplets, including enlarging the We range for bouncing and reducing the contact time. It is especially found that the rectangular ridge leads to an increased contact time compared with the flat surface in the moderate We region. The underlying mechanism of the differential effect of the rectangular ridge on the contact time is compressively elucidated by the retraction dynamics of distinct bouncing modes. Subsequently, the retraction models considering different retraction characteristics are developed for the unsplit case. To promote a universal understanding of the effect of the ridge on the retraction dynamics of nanodroplets, several typical ridge shapes (triangular, cylinder, and semi-circular) are further considered. The retraction models are extended and verified to consider the effect of the ridge shape by introducing the equivalent structure parameters. Based on such a universal understanding, a newly designed shoot-shaped ridge is proposed and can considerably reduce the contact time of unsplit nanodroplets in the moderate We region.

A new threshold selection method for species distribution models with presence-only data: Extracting the mutation point of the P/E curve by threshold regression.

Selecting thresholds to convert continuous predictions of species distribution models proves critical for many real-world applications and model assessments. Prevalent threshold selection methods for presence-only data require unproven pseudo-absence data or subjective researchers' decisions. This study proposes a new method, Boyce-Threshold Quantile Regression (BTQR), to determine thresholds objectively without pseudo-absence data. We summarize that the mutation point is a typical shape feature of the predicted-to-expected (P/E) curve after reviewing relevant articles. Analysis based on source-sink theory suggests that this mutation point may represent a transition in habitat types and serve as an appropriate threshold. Threshold regression is introduced to accurately locate the mutation point. To validate the effectiveness of BTQR, we used four virtual species of varying prevalence and a real species with reliable distribution data. Six different species distribution models were employed to generate continuous suitability predictions. BTQR and nine other traditional methods transformed these continuous outputs into binary results. Comparative experiments show that BTQR has advantages in terms of accuracy, applicability, and consistency over the existing methods.

Early history of the study of bone growth (1722–1875)

IntroductionBone growth is a fascinating process, primarily due to its complexity. Equally engaging is the history of its study, which, however, remains unknown to most anatomists and surgeons.Materials and methodsA literature search was performed in original publications and historical sources.ResultsThe early history of bone growth study may be divided into two periods. Firstly, the experimental one, between 1722 and 1847, which consisted in the study of bone growth by the drilling of benchmark holes into the diaphysis, and examination of growing bones in madder-fed animals. In the course of one century, four French scientists (Henri-Louis Duhamel du Monceau, Marie-Jean-Pierre Flourens, Gaspard Auguste Brullé and Frédéric Léopold Hugueny) and one British researcher (John Hunter) proved experimentally that the longitudinal growth of long bones occurred only at its epiphyseal ends and their final shape resulted from apposition and resorption processes taking place simultaneously both on the periosteal and intramedullary surfaces of the bone. In the second, the microscopic period (1836–1875), the physeal growth cartilage was discovered and described in detail, including its importance for the longitudinal growth of long bones. The first description of growth cartilage was published by a Swiss anatomist Miescher in 1836. Subsequently, this structure was studied by a number of English, German and French anatomists and surgeons. This whole period was concluded by Alfred Kölliker´s extensive study of bone resorption and its significance for typical bone shapes and Karl Langer´s study of the vascular supply of the growing and mature bone.ConclusionResearch by French, English, German and Swiss scientists between 1727 and 1875 yielded fundamental insights into the growth of long bones, most of which are still valid today.

Study on the characteristics of increased mechanical stiffness according to changes in LCP shape to reinforce clavicle fractures

The clavicle has various anatomic shapes unique to each individual. Additionally, with the increase in high-energy traumas such as sports injuries and traffic accidents, the patterns of fractures become complex and complicated. Thus, there is a need for a variety of shapes of locking compression plates (LCP) to accommodate different types of fractures and facilitate quicker rehabilitation. The aim of this study is to present different types of LCP that secure fracture fragments and distribute stress evenly, in comparison to typical anatomical LCPs, for reinforcing clavicle fractures. Three models were compared in this study: the typical shape, the center hole removed shape, and the double-curved wing shape. The DICOM (Digital Imaging and Communications in Medicine) file obtained from the computed tomography scan of the patient’s clavicle was used to extract the three-dimensional (3D) clavicle structure. Finite element analysis (FEA) simulation was employed to analyze the structural changes of the LCP under external forces. A reinforced jig was used to apply the same type of external force to each LCP, and an experiment was conducted to analyze the mechanical impact of the LCP’s structural characteristics. When comparing the stress values at the fracture zone point, resulting from the FEA simulation with applied bending forces, it was calculated that the stress dispersion effect was approximately ten times greater when transitioning from a typical LCP shape to a double-curved partial wing structure. Moreover, the ultimate stress increased 3.33 times, from 241.322 to 804.057 N, as the LCP design changed under cantilever bending conditions. This double-curved wing LCP design reduces stress concentration at the fracture site and minimizes stress in the fracture area when subjected to cantilever bending forces. Consequently, this newly designed LCP has the potential to decrease complications related to the plate and accelerate rehabilitation protocols.