Smooth Shape Research Articles

Postharvest short-time partial dehydration extends shelf-life and improves the quality of Actinidia arguta during low temperature storage

Actinidia arguta is a type of kiwi fruit with a smooth glabrous shape, which provides high nutritional value, a sweet and sour taste, and excellent healthcare function. However, it is a typical climacteric fruit and decomposes quickly when stored. For delaying senescence, the effect of postharvest short-time partial dehydration (STPD) on the storage quality of A. arguta was investigated under dehydration rates of 2%, 4%, and 6% coupled with storage at (2.0 ± 0.5) °C, respectively. Results showed that appropriate dehydration treatment coupled with low temperature storage inhibited the pectinase activity and the decomposition of propectin, thus maintaining fruit firmness, reducing fruit decay rate, regulating the generation of abscisic acid (ABA) delaying ethylene production, and decreasing the peak level of respiration rate. It also inhibited the reduction of total soluble solid, titratable acid, and vitamin C, maintains catalase and peroxidase activity. Based on the present study, the 4% dehydration treatment was the most effective, which extended the storage period up to 60 days and reduced the decay rate to 33%. In conclusion, it was revealed that STPD could be an effective method for retarding the losses that occurred in the fruit quality of A. arguta during cold storage.

Advanced properties of gold nanoparticles obtained by using long-chain secondary amine for phase transfer from water to chloroform

We have conducted a new comparison of gold nanoparticles functionalized by primary- and secondary amine with the same chain length. Our hypothesis suggests that the adaptive steric conformation of the secondary amine molecular branches makes a marked additional contribution to the well-established role of the ligand chain length. We characterize the importance of this factor based on diOctadecylamine (diODA) and Octadecylamine (ODA) passivated gold nanoparticles by using high-resolution transmission electron microscopy (HR-TEM) and selective area electron diffraction (SAED). The results evidenced that the diODA coordination to the inorganic core forms a more efficient and impenetrable protective coating. The SAED patterns show a more homogeneous distribution of the small crystalline domains in the gold core. TEM images show a smooth spherical shape of the diODA nanoparticles and a lack of interparticle coalescence cases. The diODA-passivation provides nanoparticles with nearly twice the effective ligand length than its ODA equivalent. This results in their spontaneous arrangement in domains with expressed crystal-like order despite the relatively large size-dispersity before passivation. The surface free energy of coatings, formed by diODA passivated gold nanoparticles, is twice as small as measured on the ODA-nanoparticle-coated surfaces.

Aesthetic Design and Evaluation of Public Facilities in Railway Stations under the Background of Sustainable Development: A Case of an Information Counter at Xiong’an Railway Station

Sustainable development is an important trend for railway stations, and public facilities are essential parts of railway stations. With the sustainable development of railway station construction, the aesthetic design of public facilities is a problem that needs to be solved in the field of industrial design. In this context, this study proposed an aesthetic design and evaluation method for public facilities in railway stations. This method is constructed by combining the Kansei image and AHP (analytic hierarchy process)–FCE (fuzzy comprehensive evaluation) model, and takes the information counter at Xiong’an railway station as an example to illustrate the method. JACKTM is applied to evaluate the ergonomics of the design scheme. The results are as follows. (1) Ecological culture is an important source of Kansei images for aesthetic designs in the context of sustainable development. Kansei words, such as understated, delicate, dynamic, and others, which reflect original simplicity and original nature, are typical semantic features. Simple and smooth shapes are typical form features. (2) An aesthetic design is a system of various elements; the core content of an aesthetic design is to reflect the original aesthetic feeling. On this basis, the elements of simple, harmonious, humanized, and natural constitute the aesthetic design principle. This method is suitable for the aesthetic design and evaluation of public facilities in railway stations, which could provide valuable guidance for the aesthetic design of public facilities in railway stations under the background of sustainable development.

Spectroscopic and antibacterial activities of cobalt and nickel nanoparticles: a comparative analysis

This study aimed to compare the spectroscopy, morphological, electrocatalytic properties, and antibacterial activities of cobalt nanoparticles (CoNPs) with nickel nanoparticles (NiNPs). Cobalt nanoparticles and NiNPs were prepared via a chemical reduction approach and characterized utilizing transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), and X-ray diffraction (XRD) techniques. The result from XRD and TEM analysis revealed that the synthesized nanoparticles exhibit face-centered cubic with smooth spherical shape, having average particles size of 12 nm (NiNPs) and 18 nm (CoNPs). The electrochemical properties of the nanoparticles were examined via cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. The CV results showed that GCE-Ni (35.6 μA) has a higher current response compared to GCE-Co (10.5 μA). The EIS analysis revealed that GCE-Ni (1.39 KΩ) has faster electron transport capability compared to GCE-Co (2.99 KΩ) as indicated in their Rct values. The power density of the synthesized nanoparticles was obtained from their "knee" frequency (f°) values, with GCE-Ni (3.16 Hz) having higher f° values compared to GCE-Co (2.00 Hz). The antibacterial activity of the nanoparticles was evaluated against multidrug-resistant Escherichia coli O157, Escherichia coli O177, Salmonella enterica, Staphylococcus aureus, and Vibrio cholerae. The result from the antibacterial study revealed that at low concentrations both CoNPs and NiNPs have significant antibacterial activities against E. coli O157, E. coli O177, S. enterica, S. aureus, and V. cholerae. NiNPs showed better antibacterial activities at low concentrations of 61.5, 61.5, 125, 61.5, and 125 µg/mL compared to CoNPs with minimum inhibitory concentrations of 125, 125, 250, 61.5, and 125 µg/mL against E. coli O157, E. coli O177, S. enterica, S. aureus, and V. cholerae, respectively. These promising antibacterial activities emphasize the potential of CoNPs and NiNPs as effective antibacterial agents, which could aid in the development of novel antibacterial medicines.

Active compound shape/vibration control of piezo-actuated variable camber wing section via hybrid feedback/feedforward control scheme

The new concept of compliant morphing wings with piezoelectric conformal actuators has presented its unique advantages compared with rigid morphing wings, but it has also brought a new challenge to design and control. In this study, a compound shape/vibration control strategy for one kind of piezocomposite actuated wing with variable camber is proposed with the purpose to realize a fast, smooth shape morphing process, while overcoming epiphytic vibration problems due to the necessary structural flexibility. A piezo-actuated variable trailing edge wing section was designed by using a compliant corrugated structure installed with actuators made of Macro Fiber Composite (MFC). A compound shape/vibration control system was designed in terms of active disturbance rejection control (ADRC) strategy combined with a feedforward compensator for the MFC actuators to eliminate the nonlinear hysteretic/creep issues. An experimental device was established for verification. The experimental results show that rapid, accurate shape morphing can be achieved with the proposed hybrid feedforward/feedback control scheme while suppressing structural vibration. The compound control of low-frequency shape control and high-frequency vibration suppression can be synergistically realized, and the deformation and stability while controlling such compliant morphing wings can be properly balanced. The proposed compound control strategy is a feasible way to realize favorable dynamic control performance of compliant morphing wings in the future.

Study on the Effect of Asphalt Static Conditions on the Tensile Properties of Acidic Aggregate Hydraulic Asphalt Concrete.

Hydraulic asphalt concrete is known for its excellent seepage control performance and strong deformation resistance. This engineering material has widespread applications in the seepage control structures of hydraulic buildings. Recent projects have investigated the use of acidic aggregates to improve economic efficiency. However, they have also highlighted the weaker adhesion between acidic aggregates and asphalt, which necessitates stringent construction process control. This study investigates the impact of resting conditions on the tensile properties of acidic aggregate hydraulic asphalt concrete. The results of the tensile testing indicate that the storage time significantly affects the performance of asphalt concrete. The tensile strength of the specimens without anti-stripping agents decreased from 1.711 MPa to 0.914 MPa after resting periods of 0, 10, 20, and 30 days. The specimens treated with anti-stripping agents also showed a decrease in tensile strength over time, similar to the trend observed in the previous specimens. Digital specimen simulations indicated a decrease in cohesion between the asphalt and the aggregate from 5.375 MPa to 2.664 MPa after 30 days, representing a reduction of 50.44%. To counteract the effect of the storage time on the bonding between acidic aggregates and asphalt, this study recommends reducing the grading index and maximum size of aggregates, decreasing the coarse aggregate content, and selecting smooth aggregate shapes.

Shape from dots: a window into abstraction processes in visual perception

IntroductionA remarkable phenomenon in perception is that the visual system spontaneously organizes sets of discrete elements into abstract shape representations. We studied perceptual performance with dot displays to discover what spatial relationships support shape perception.MethodsIn Experiment 1, we tested conditions that lead dot arrays to be perceived as smooth contours vs. having vertices. We found that the perception of a smooth contour vs. a vertex was influenced by spatial relations between dots beyond the three points that define the angle of the point in question. However, there appeared to be a hard boundary around 90° such that any angle 90° or less was perceived as a vertex regardless of the spatial relations of ancillary dots. We hypothesized that dot arrays whose triplets were perceived as smooth curves would be more readily perceived as a unitary object because they can be encoded more economically. In Experiment 2, we generated dot arrays with and without such “vertex triplets” and compared participants’ phenomenological reports of a unified shape with smooth curves vs. shapes with angular corners. Observers gave higher shape ratings for dot arrays from curvilinear shapes. In Experiment 3, we tested shape encoding using a mental rotation task. Participants judged whether two dot arrays were the same or different at five angular differences. Subjects responded reliably faster for displays without vertex triplets, suggesting economical encoding of smooth displays. We followed this up in Experiment 4 using a visual search task. Shapes with and without vertex triplets were embedded in arrays with 25 distractor dots. Participants were asked to detect which display in a 2IFC paradigm contained a shape against a distractor with random dots. Performance was better when the dots were sampled from a smooth shape than when they were sampled from a shape with vertex triplets.Results and discussionThese results suggest that the visual system processes dot arrangements as coherent shapes automatically using precise smoothness constraints. This ability may be a consequence of processes that extract curvature in defining object shape and is consistent with recent theory and evidence suggesting that 2D contour representations are composed of constant curvature primitives.

Planar quartic G2 Hermite interpolation for curve modeling

We study planar quartic G2 Hermite interpolation, that is, a quartic polynomial curve interpolating two planar data points along with the associated tangent directions and curvatures. When the two specified tangent directions are non-parallel, a quartic Bézier curve interpolating such G2 data is constructed using two geometrically meaningful shape parameters which denote the magnitudes of end tangent vectors. We then determine the two parameters by minimizing a quadratic energy functional or curvature variation energy. When the two specified tangent directions are parallel, a quartic G2 interpolating curve exists only when an additional condition on G2 data is satisfied, and we propose a modified optimization approach. Finally, we demonstrate the achievable quality with a range of examples and the application to curve modeling, and it allows to locally create G2 smooth complex shapes. Compared with the existing quartic interpolation scheme, our method can generate more satisfactory results in terms of approximation accuracy and curvature profiles.

Effects of co-assembly of gliadin and carboxymethyl cellulose on the high internal phase pickering emulsions: Rheology properties, 3D printing performance and oil-soluble nutrient delivery

High internal phase Pickering emulsions (HIPPEs) stabilized with gliadin-based particles have received considerable attention because of the advantages of easy access, low cost and clean label. However, the relatively weak self-supporting and thixotropic recovery properties limit their application in food 3D printing. The present study investigated the effects of co-assembly of gliadin and carboxymethyl cellulose (CMC) on the gel network structure, viscoelasticity, thixotropic recovery, 3D printing properties and β-carotene delivery performance of HIPPEs stabilized with gliadin-based colloid particles. The results showed that the combination of gliadin and CMC significantly enhanced the density of gel network structure of HIPPEs and endowed the HIPPEs solid-like viscoelasticity, moderate shear thinning behavior and excellent thixotropic recovery rate as well as 3D printability. The HIPPEs realized an optimal performance at a gliadin/CMC mass ratio of 2:1, with a thixotropic recovery rate up to 93.23 ± 0.72 %, and the corresponding printed 3D model had a smooth surface, regular shape, and good printing accuracy. In addition, the potential application of HIPPEs in delivery of oil-soluble nutrients was investigated using β-carotene as a model. The result suggested that the stability and bioaccessibility of β-carotene was significantly improved from 25.71 ± 0.29 % to 59.70 ± 0.99 % and 12.30 ± 0.11 % to 37.04 ± 0.76 % respectively as the existence of CMC. This study provides references for the construction and design of food 3D printing materials.

Selection of Appropriate Criteria for Optimization of Ventilation Element for Protective Clothing Using a Numerical Approach

While there are multiple methods to ventilate protective clothing, there is still room for improvement. In our research, we are using ventilation elements that are positioned at the ventilation holes in the air space between the body and clothing. These ventilation elements allow air to flow freely while preventing sun radiation, rain drops, and insects from directly accessing the body. Therefore, the shape of the ventilation element is crucial. This led us to study the shape optimization of ventilation elements through the utilization of metamodels and numerical approaches. In order to accomplish the objective, it is crucial to thoroughly evaluate and choose suitable criteria for the optimization process. We know from prior research that the toroidal cut-out shape element provides better results. In a previous study, we optimized the shape of this element based on the minimum pressure difference as a criterion. In this study, we are using different criteria for the shape optimization of ventilation elements to determine which are most effective. This study involves a metamodeling strategy that utilizes local and global approximations with different order polynomials, as well as Kriging approximations, for the purpose of optimizing the geometry of ventilation elements. The goal was achieved by a sequential process. (1) Planning the position of control points of Non-Uniform Rational B-Splines (NURBS) in order to generate elements with a smooth shape. (2) Constructing geometric CAD models based on the design of experiments. (3) Compute detailed model solutions using SolidWorks Flow Simulation. (4) Developing metamodels for responses using computer experiments. (5) Optimization of element shape using metamodels. The procedure is repeated for six criteria, and subsequently, the results are compared to determine the most efficient criteria for optimizing the design of the ventilation element.

Development of Bacillus subtilis Detection Method Targeting Genes codY, narH, and ureC Using Polymerase Chain Reaction

Bacillus subtilis, a causative agent of foodborne illness in bread, cakes, cereals, and cheese leading to symptoms like diarrhea and nausea, was investigated for its role in nosocomial infections, including endocarditis, bacteremia, septicemia, and meningitis. The research focused on three genes: codY, narH, and ureC, which respectively contribute to bacterial survival through biofilm and spore formation, acid resistance, and adaptation to anaerobic conditions. The objective of this study was to evaluate the codY, narH, and ureC genes using the Gradient PCR method for Bacillus subtilis detection in bread and cheese through Real-Time PCR. During the research, bacterial growth was observed with an OD600 of 1.438 in Tryptic Soy Broth (TSB), and colonies of medium size, smooth, cream-coloured, and round shape were successfully isolated on Tryptic Soy Agar (TSA). The DNA template used had a 71.5 ng/µL concentration with an A260/280 ratio of approximately 1.830. The annealing temperature for Gradient PCR used was 53-62°C. The primers successfully amplified codY (175 bp), narH (222 bp), and ureC (153 bp) gene amplicons. The optimal annealing temperature for the primers used was 60°C, as indicated by the presence of a single bright band in electrophoresis. Using these three different genes, testing can also be conducted with the Multiplex PCR method. The next step involves developing a detection kit using optimized primers and annealing temperatures for the identification of Bacillus subtilis in bread and cheese samples using Real-Time PCR.

Optimization of single-track deposits in wire arc-based direct energy deposition of ER110S-G steel using MONS-MFO and TOPSIS algorithms

Wire and arc-based direct energy deposition (wire and arc DED) is a promising metallic additively manufacturing (MAM) technology to fabricate large-size metallic components. Among high-strength-low-alloy steels used in wire and arc DED processes, ER110S-G is a commonly used material. However, previous studies have often relied on process parameters recommended by suppliers for conventional welding methods. This study aims to predict the optimum processing parameters for the manufacture of ER110S-G steel by a wire and arc DED process based on experiment and multi-attribute optimization algorithms. The experiment was designed using the full factorial method with the input variables ( U– voltage, I– current, and v– traveling speed) while considering three attributes of single tracks ( STW– single track width, STH– single track height, and LMP– length of melting pool). To find the optimal processing variables, MONS-MFO (Multi-Objective Non-Sorted Moth Flame) was utilized. The outcomes reveal that the developed predictive models of attributes feature a high accurate level ( R2 = 98.11%, 98.38%, and 98.07% for STW, STH, and LMP, respectively). The optimal parameters obtained by MONS-MFO & TOPSIS were I = 159.4 A, v = 0.3 m/min, and U = 21.4 V allow fabricating single tracks with smooth and regular shape and a s-shaped thin-wall component with regular shape and height. Moreover, no spatters generated with the optimal parameters, demonstrating their suitability and efficiency for the printing process.

Unified Adversarial Patch for Visible-Infrared Cross-Modal Attacks in the Physical World.

Physical adversarial attacks have put a severe threat to DNN-based object detectors. To enhance security, a combination of visible and infrared sensors is deployed in various scenarios, which has proven effective in disabling existing single-modal physical attacks. To further demonstrate the potential risks in such cases, we design a unified adversarial patch that can perform cross-modal physical attacks, achieving evasion in both modalities simultaneously with a single patch. Given the different imaging mechanisms of visible and infrared sensors, our work manipulates patches' shape features, which can be captured in different modalities when they undergo changes. To deal with challenges, we propose a novel boundary-limited shape optimization approach that aims to achieve compact and smooth shapes for the adversarial patch, making it easy to implement in the physical world. And a score-aware iterative evaluation method is also introduced to balance the fooling degree between visible and infrared detectors during optimization, which guides the adversarial patch to iteratively reduce the predicted scores of the multi-modal sensors. Furthermore, we propose an Affine-Transformation-based enhancement strategy that makes the learnable shape robust to various angles, thus mitigating the issue of shape deformation caused by different shooting angles in the real world. Our method is evaluated against several state-of-the-art object detectors, achieving an Attack Success Rate (ASR) of over 80%. We also demonstrate the effectiveness of our approach in physical-world scenarios under various settings, including different angles, distances, postures, and scenes for both visible and infrared sensors.

Particle removal from solid surfaces via an impinging gas jet pulse: Comparison between experimental and CFD-DEM modeling results

Computational and experimental studies are performed to investigate the influence of a gas jet pulse impinging perpendicularly onto a flat solid surface seeded with a monolayer of spherical particles. A numerical resuspension model is derived to predict particle release into the gas phase during jet impingement. To this end, discrete particles are immersed in a continuous gas phase modeled via Large Eddy Simulation to capture the effect of jet turbulence on the particle detachment process. Two-way coupling between particulate and gas phase is established via a near-wall particle drag model and a lift model. Direct particle–wall interactions are captured with adhesion, rolling friction and sliding friction models. To validate the overall modeling approach, numerical results are compared with resuspension experiments for monodisperse polystyrene particles placed on a glass slide. Simulations show that the particles preferentially mobilize by rolling, followed to a limited extend by lift off from the solid surface driven by aerodynamic forces and particle–particle collisions. Resuspension occurs in the first instants after jet impingement. Computational and experimental results for removal efficiency Γ are in good agreement in terms of the location of their r50 parameter, i.e., the radial position where 50% of the particles have been removed by the jet; both results show a linear dependence between the r50 value and the jet Reynolds number of the impinging jet. However, experimental Γ(r) curves generally have a smooth sigmoidal shape whereas numerical results predict a sharp transition. Some model shortcomings are identified which lead to an underprediction of particle lift-off and which explain the observed differences. Furthermore, the experimental Γ curves nearly collapse onto each other when plotted over the predicted local wall-shear stress.

Development and assessment of sustainable steel-concrete composite beams with novel demountable shear connections

The design of sustainable steel-concrete composite beams (SSCCBs) with demountable shear connections (DSCs) for deconstructability can improve the problem of construction and demolition waste during these construction activities, and it also strengthens the sustainability of a building by allowing for easy dismantling and the reuse or recycling of structural components at the service load and easy replacing the damaged members to achieve the resilience capacity after earthquake. In this study, the structural configuration and concept design of novel SSCCBs using DSCs were firstly introduced. The nonlinear finite element models (FEMs) using the Abaqus software were validated in terms of the load versus mid-span deflection curves and failure modes of the similar composite beams given by the experimental data. A parametric study was implemented to identify the influence of the following variables: geometric size, strength grade, inclination angle and shape of concrete plug, diameter and strength grade of connected bolt, steel grade and width and grade of slab concrete. It was found that geometric size, grade and smooth shape of concrete plug could optimize the performance level of occupancy while bolt diameter and grade enhanced the reuse behavior at service loads. Additionally, increasing the bolt diameter and steel grade led to an increase by 8–10% in the equivalent ultimate strength and to decrease the ductility of the whole beams obviously. Bolt diameter, steel grade and slab width have quite influences on the stiffness due to increase the interaction degree of these prefabricated components. Based on the theoretical and parametric analysis results, simple design method of ultimate moment capacity for this SSCCBs with DSCs is proposed to facilitate design practice.

Wrinkling–dewrinkling transitions in stretched soft spherical shells

Soft shells undergoing intricate buckling and morphological evolutions can serve as a model system for understanding the morphogenesis of organs, tissues, cells, and nuclei. In this paper, we combine experiments, simulations, and theoretical analysis to investigate the wrinkling and subsequent morphological transitions in a soft spherical shell subjected to an outward concentrated force. During loading, the spherical shell first buckles into many shallow radial wrinkles, which soon merge into a single crater-like deep wrinkle, and then the number of wrinkles increases with loading. Surprisingly, after a critical point, all wrinkles disappear and the shell regains an axisymmetric, smooth shape, referred to as dewrinkling. We show how this anomalous wrinkling–dewrinkling transition stems from the interplay between surface curvature and large deformations. Material-independent scaling laws are established from an energy analysis to predict the surface wrinkling pattern, which depends on the loading force. This work provides physical insights into how local forces can regulate the shape evolutions of soft shells, which can take place in, for example, the morphogenesis of developing organisms.

Bead geometry prediction and optimization for corner structures in directed energy deposition using machine learning

Wire Arc Additive Manufacturing as a Directed Energy Deposition technology has disruptive potential for modern manufacturing. The technology comes with the flexibility and material efficiency of additive manufacturing processes while mitigating the disadvantages through high material deposition rates and high energy efficiency. However, the prevalence of the technology is inhibited by its geometrical inaccuracy and the large induced residual stresses. This work tackles the former problem by capturing the process parameter-geometry relationship using Machine Learning. To do so, multiple mild steel welding beads with varying shape features like corner angles are printed using a Metal Inert Gas welding machine attached to an industrial robot. The cross-sectional profile of the printed beads is measured using a point laser sensor and correlated through a Multilayer Perceptron to input features such as travel speed, wire feed speed, and shape features. By incorporating varying corner angles, a holistic model, not limited to geometry prediction of straight beads only, is trained. Using the model, excess material at the inner angle of corners determined by the overlapping regions of the two adjacent beads can be predicted. By generating a database of possible bead shapes an inverse algorithm that suggests welding parameter combinations that yield a smooth bead shape at the corner is created, thus enabling improvement of the overall accuracy of the Wire Arc Additive Manufacturing process.

Neodymium adsorption from aqueous solution by β-cyclodextrin nanosponges and a polymer valorized from potato peels waste: experiments and conventional and statistical physics interpretations.

Using organic waste and residue streams to be turned into valuable and greener materials for various applications has proven an efficient and suitable strategy. In this work, two green materials (nanosponges and a polymer) were synthesized using potato peels and applied for the first time to adsorb and recover Neodymium (Nd3+) from aqueous solutions. The recovery of Nd3+ that belongs to the rare earth elements has attracted important interest due to its/their importance in several industrial and technological applications. The fine potato peel waste (FPPW) polymer presented an irregular shape and porous surface. At the same time, the β-cyclodextrin (β-CD) nanosponges had uniform distribution with regular and smooth shapes. β-CD nanosponges exhibited a much higher total carboxyl content (4.02mmolg-1) than FPPW (2.50mmolg-1), which could impact the Nd3+ adsorption performance because carboxyl groups can interact with cations. The adsorption capacity increased with the increase of the pH, reaching its maximum at pHs 6-7 for β-CD nanosponges and 4-7 for FPPW polymer. The kinetic and equilibrium data were well-fitted by General order and Liu models. β-CD nanosponges attained adsorption capacity near 100mg Nd per gram of adsorbent. Thermodynamic and statistical physical results corroborated that the adsorption mechanism was due to electrostatic interaction/complexation and that the carboxyl groups were important in the interactions. β-CD nanosponges (three cycles of use) were more effective than FPPW (one cycle of use) in the regeneration. Finally, β-CD nanosponges could be considered an eco-friendly adsorbent to recover Nd3+ from aqueous matrices.

The geometric evolution of aortic dissections: Predicting surgical success using fluctuations in integrated Gaussian curvature.

Clinical imaging modalities are a mainstay of modern disease management, but the full utilization of imaging-based data remains elusive. Aortic disease is defined by anatomic scalars quantifying aortic size, even though aortic disease progression initiates complex shape changes. We present an imaging-based geometric descriptor, inspired by fundamental ideas from topology and soft-matter physics that captures dynamic shape evolution. The aorta is reduced to a two-dimensional mathematical surface in space whose geometry is fully characterized by the local principal curvatures. Disease causes deviation from the smooth bent cylindrical shape of normal aortas, leading to a family of highly heterogeneous surfaces of varying shapes and sizes. To deconvolute changes in shape from size, the shape is characterized using integrated Gaussian curvature or total curvature. The fluctuation in total curvature (δK) across aortic surfaces captures heterogeneous morphologic evolution by characterizing local shape changes. We discover that aortic morphology evolves with a power-law defined behavior with rapidly increasing δK forming the hallmark of aortic disease. Divergent δK is seen for highly diseased aortas indicative of impending topologic catastrophe or aortic rupture. We also show that aortic size (surface area or enclosed aortic volume) scales as a generalized cylinder for all shapes. Classification accuracy for predicting aortic disease state (normal, diseased with successful surgery, and diseased with failed surgical outcomes) is 92.8±1.7%. The analysis of δK can be applied on any three-dimensional geometric structure and thus may be extended to other clinical problems of characterizing disease through captured anatomic changes.

PUNCTURE LASER MICRODISCECTOMY IN THE TREATMENT OF SEQUESTERED HERNIATION OF LUMBAR INTERVERTEBRAL DISCS

Objective. to improve the results of treatment of sequestered herniation of lumbar intervertebral discs by the puncture laser microdiscectomy (PLM) method. Methods. During the period from 2000 to 2023, 132 patients with sequestered lumbar disc herniations were operated on by the PLM method. There were 88 males and 34 females. The age of the patients was from 23 to 64 (42.3 ± 3.5) years. Surgeries were performed using a C-arc operating fluoroscope. The laser pulse duration — 0.3–0.5 sec, and radiation exposure — 500–600 J. Approach to the sequestrum was mainly posteromedian transdural. For laterally located sequestra, posterolateral approach was used. The efficacy of PLM was assessed by pain intensity reduction according to the VAS scale one month after surgery, and according to the McNab scale 3 months after surgery. Results. One month after PLM, the maximum reduction of radicular pain intensity was noted in patients with posteromedian hernias, to a lesser extent — with paramedian hernias, and the least pronounced — with lateral hernias. However, no statistically significant differences in pain intensity one month after surgery depending on hernia location were found (p > 0.05). As for the intensity of lumbar pain, in all groups, regardless of hernia location, it significantly decreased and did not exceed 1 point after one month. 3 months after surgery, 95 (71.9 %) patients had an excellent result according to the McNab scale, 13 (9.8 %) — good, 7 (5.3 %) — satisfactory, 17 (12.8 %) — unsatisfactory, indicating that the PLM method of sequestered hernias can be quite effective in a certain selection of patients. According to our data, positive results can reach 81.8 % (95 % CI 74.2–87.9 %) (CI — confidence interval). Conclusions Sequestered hernias, which can be operated by the PLM method, should not exceed 9 mm in height on axial sections, should have a smooth rounded lenticular shape without signs of migration. The positive effect of PLM of sequestered hernias reached 81.7 %. The results were better with PLM of posteromedian hernias.