Intersection Points Research Articles

High-accuracy fringe projection profilometry without phase unwrapping based on multi-view geometry constraints

The number of fringes and phase unwrapping in fringe projection profilometry result in two key factors. The first is to avoid the problems of excessive fringe patterns, and the second is phase ambiguity. This paper presents a three-dimensional (3D) measurement method without phase unwrapping. This method benefits from the geometric constraints and does not require additional images. Meanwhile, epipolar rectification is performed to calibrate the rotation matrix relationship between the new plane of the dual camera and the plane of the projector. Subsequently, using depth constraints, the point pairs with incorrect 3D positions are effectively eliminated, and the initial parallax map is obtained by establishing epipolar lines of the left and right matching points in the projector domain, obtaining the intersection points, and setting up the threshold for filtering. Finally, a function combining the modulation intensity and phase is proposed to refine the parallax map such that the 3D result is insensitive to phase error. The standard step block and standard ball were used to verify the validity of the proposed method, and the experimental results showed that the root mean square error of the method was 0.052 mm.

Viral ecologies: Resurgent nature, COVID-19 and the discourse of transgender contagion

During the early days of the COVID-19 pandemic, popular narratives of a ‘resurgent nature’ and portrayals of the virus as a form of ‘revenge’ prompted geographical reflection on the promises and limitations of ecological perspectives on the SARS-CoV-2 virus. Revisiting these reflections in the light of what we have learned from the pandemic, this article asks what is to be gained by attempting to think critically with the virus about human space as multispecies composition. Thinking ecologically with the virus can become a method for critically reconsidering naturalised and dualistic orders of exclusion and inclusion, health and unhealth, or belonging and unbelonging. Specifically, we focus in this article on the overlap of immunological and trans-antagonistic discourses with viral imaginaries of the pandemic, exploring the paradox of vulnerability that arises at this point of intersection. COVID-19 simultaneously highlights humans’ mutual vulnerability as a horizontalising force and amplifies differential social vulnerabilities. In examining this paradox of vulnerability as it relates to viral discursive constructions of transness, we explore tensions between different modes of engaging, identifying and thinking with the virus in recognition that the social and the ecological cannot properly be considered as separate domains. The aim is not simply to propose an extended epidemiology that takes into account the complex human–nonhuman entanglement, but to explore the social, cultural and political implications of pandemic vulnerabilities and of thinking ecologically with the virus. We trace the shared conceptual underpinnings of ecological and immunological thought, showing that these same conceptual lineages manifest in political responses to the COVID-19 pandemic and exploring how they are expressed in queer- and trans-antagonistic discourse and policy. Building on these analyses, we develop a proposal for ‘transing’ the virus and a model for ‘thinking ecologically’ that is simultaneously liberatory, messy and agnostic.

Twins of conic hexagons

Six points on a conic section define 60 different hexagons and therefore 60 Pascal lines. Each Pascal line passes through three of the 45 intersections of connecting lines of the six given points. Instead of searching for collinear triples (Pascal lines) among these 45 points, we identify and classify all six-tuples among the 45 points that lie on a conic section. These six-tuples will be called Pascal twins of the given six points. It turns out that there are also six-tuples that lie on a conic section that have two points in common with the given six points. These six-tuples are called Siamese Pascal twins for evident reasons.

Human foot force informs balance control strategies when standing on a narrow beam.

Despite the abundance of studies on the control of standing balance, insights about the roles of biomechanics and neural control have been limited. Previous work introduced an analysis combining the direction and orientation of foot-ground forces. The "intersection point" of the lines of actions of these forces exhibited a consistent pattern across healthy, young subjects when computed for different frequency components of the center of pressure signal. To investigate the control strategy of quiet stance, we applied this intersection point analysis to experimental data of 15 healthy, young subjects balancing in tandem stance on a narrow beam and on the ground. Data from the sagittal and frontal planes were analyzed separately. The task was modeled as a double-inverted pendulum controlled by an optimal controller with torque-actuated ankle and hip joints and additive white noise. To test our prediction that the controller that minimized overall joint effort would yield the best fit across the tested conditions and planes of analyses, experimental results were compared with simulation outcomes. The controller that minimized overall effort produced the best fit in both balance conditions and planes of analyses. For some conditions, the relative penalty on the hip and ankle joints varied in a way relevant to the balance condition or to the plane of analysis. These results suggest that unimpaired quiet balance in a challenging environment can be best described by a controller that maintains minimal effort through the adjustment of relative ankle and hip joint torques. NEW & NOTEWORTHY This study explored balance control in humans during a challenging task using the novel intersection point analysis, based on foot-ground force direction and point of application. Experimental data of subjects standing on a narrow beam in tandem stance were compared with modeling results of a double-inverted pendulum. The analysis showed that individuals minimized effort by adjusting ankle and hip torques, shedding light on the interplay of biomechanics and neural control in maintaining balance.

On bifurcation of non-isolated singular points arising in a problem of two-phase fluid motion in a pipe

The dynamics of gas suspension in a pipe is studied. It is described by a system of three autonomous differential equations, whose equilibrium (singular) points are not isolated, but form several continuous curves. One of these curves belongs to the transonic plane. The dynamics in a neighborhood of this plane is interesting from the physical viewpoint. In this work, the dynamics in a neighborhood of the curves of singular points is investigated. The main tools of this work are the center manifold theorem and the reduction principle. A peculiarity of the system is that the curves of singular points intersect each other. Moreover, at the intersection point a bifurcation occurs. Results of the work are the description of the dynamics in a neighborhood of singular points, the proof that a curve of singular points belongs to a center manifold and the description of the bifurcation, which occurs at the intersection point of the curves of singular points.

The Method but Not the Protocol Affects Lactate-Threshold Determination in Competitive Swimmers.

The study validated variables corresponding to lactate threshold (LT) in swimming. Speed (sLT), blood lactate concentration (BLLT), oxygen uptake (VO2LT), and heart rate (HRLT) corresponding to LT were calculated by 2 different incremental protocols and validated in comparison with maximal lactate steady state (MLSS). Ten competitive swimmers performed a 7 × 200-m front-crawl incremental "step test" with 2 protocols: (1)with 30-second rests between repetitions (short-rest incremental protocols) and (2)on a 5-minute cycle (swim + rest time, long-rest incremental protocols). Five methods were used for the assessment of sLT and corresponding BLLT, VO2LT, and HRLT: intersection of 2 lines, Dmax, modified Dmax, visual inspection, and intersection of combined linear and exponential regression lines. Subsequently, swimmers performed two to three 30-minute continuous efforts to identify speed (sMLSS) and physiological parameters corresponding to MLSS. Both protocols resulted in similar sLT and corresponding physiological variables (P > .05). Bland-Altman plots showed agreement between protocols (sLT, bias: -0.017 [0.002]m·s-1; BLLT, bias: 0.0 [0.5]mmol·L-1; VO2LT, bias: -0.1 [2.2]mL·kg-1·min-1; HRLT. bias: -2 [8]beats·min-1). However, sLT calculated by modifiedDmax using short rest was higher compared with speed at MLSS (1.346 [0.076] vs 1.300 [0.101]m·s-1; P < .05). Calculated sLT, BLLT, VO2LT, and HRLT using all other methods in short-restand long-rest incremental protocols were no different compared with MLSS (P > .05). Both 7 × 200-m protocols are valid for determination of sLT and corresponding physiological parameters, but the modifiedDmax method may overestimate sLT.

Anatomical Study of Abdominal Wall Muscle Innervation to Optimize Retroperitoneal Vascular Approach

INTRODUCTIONDifferent surgical approaches are used in aortic surgery. Retroperitoneal approaches can result in abdominal wall weakness and flank bulging. These approaches often require dissection of the anterolateral or anteromedial muscles of the abdominal wall. During dissection, the underlying nerves are at great risk of injury, which induces significant complications in abdominal wall muscles. Few studies have been conducted to minimize the risk of injury to these nerves. OBJECTIVESThis study aims to describe the trajectory of abdominal muscle motor nerves and their relationship to ribs and other anatomical landmarks. The secondary objective is to optimize surgical approaches by preserving the nerves. METHODWe conducted 12 dissections on fresh cadavers. Nerve trajectories, communication between the intercostal nerves (9th–10th–11th) and the subcostal nerve (12th), and the distance from the nerve to the estimated projection point of intersection with the abdominal midline, umbilicus, and iliac crest was recorded. RESULTSOur dissections identified the 12th subcostal nerve as the largest nerve. The 11th intercostal nerve exhibits more accessory branches than other nerves. Multiple communications and branches were observed between the 10th and 11th intercostal nerves and between the 11th and 12th nerves in the region from the anterior axillary line to the mid-clavicular line. The estimated projection point of intersection with the midline was 7.92 ± 1.24 cm supraumbilical for the 9th intercostal nerve, 3.92 ± 1.18 cm supraumbilical for the 10th, 1.08 ± 1.52 cm at the umbilical level for the 11th, and -3.33 ± 0.83 cm infraumbilical for the subcostal nerve. The distance between the iliac crest and the iliohypogastric nerve in the lateral jackknife position was 2.54 ± 0.65 cm. The 11th nerve had an angle in relation to the rib of between -45° and -10° (average: -24.6°), and the 12th nerve had a similar angle of between -30° and 0° (average: -18.3°). For the 11th nerve, the distance was between 0 and 5.5 cm (average: 2.92 cm); for the 12th nerve, it was between 0 and 3.0 cm (average: 1.71 cm). CONCLUSIONTo preserve the 11th nerve, the optimal approach is a straight incision starting from the upper edge of the 11th rib towards the midline, 4 cm above the umbilicus; for the 12th nerve, the optimal approach is a straight incision starting from the upper edge of the 12th rib towards the midline, 1 cm below the umbilicus; for the iliohypogastric nerve, the optimal approach is an incision close to the iliac crest at a distance <1.5 cm. The estimated projection point of intersection between the nerve directions towards the midline can indicate the anatomical trajectory of nerves. A nerve projection towards the midline can provide valuable information about the anatomical location of a nerve. This study has utility in optimizing surgical approaches. A clinical study can confirm these anatomical results.

Oswald Mathias Ungers and Sol LeWitt: Variations

One of the fundamentals of Oswald Mathias Ungers work is the definition of a new unity between art and architecture. What this investigation is focused on is the identification of the intersection point between art and architecture, considering the project for the Entrance to the Kaiserthermen in Trier (2003-2007) as case study, revealing the system of theoretical, methodological and compositional correspondences. Plastic art is Ungers' main interlocutor: one of the author's most important references is Sol LeWitt (1928-2007), an artist he admired and collected. Setting the work of Oswald Mathias Unger and Sol LeWitt side by side, offers the opportunity to underline the shared interpretation that the two authors have of the world of forms postulated by Henri Focillon (1881-1943) in Life of Forms, according to which form, autonomous with respect to time and place, has its own universe, governed by its own laws, space and matter. According to these premises, we propose to read Trier's building through the instruments of art, following the hypothesis that in this project art embodies a creative and positive component in the definition of architecture, a cultural stimulus that guides the author in the design process.

Activation of muscle amine functional groups using eutectic mixture to enhance tissue adhesiveness of injectable, conductive and therapeutic granular hydrogel for diabetic ulcer regeneration

Herein, Polydopamine-modified microgels and microgels incorporated with superficial epoxy groups were synthesized and applied as precursors for the fabrication of four granular hydrogels. To enhance the tissue adhesiveness, a ternary deep eutectic solvent was synthesized to activate the muscle amine functional groups facilitating the formation of robust NC bonds at ambient conditions. At a certain shear rate of 10 s−1, hydrogel DMG displayed a viscosity of 9×103 Pa/s, representing the highest complex viscosity among the tested hydrogels primarily driven by quinone groups in PDA which enhanced reversible interactions, thereby increasing particle cohesion. Moreover, the intersection point escalating from about 4×103 to approximately 9×104 as the concentration of DMG increased from 0 % (for MG) to 70% (7D3MG) by weight. There was a decrease in adhesion strength from 0.45 ± 0.08 N in MG to 0.39 ± 0.16 N, 0.35± 0.18 N, and 0.33 ± 0.15 N for 3D7MG, 7D3MG, and DMG respectively, suggesting that MG was capable of forming numerous covalent bonds, thereby enhancing its adhesion to the substrate. The type of eutectic mixture affected the electrical conductivity and a very important point was the changes in resistance value with time. For MG catalyzed by [DES]AZG, the resistance increased only by 1.3 % (from 3.37 to 3.81 kΩ) at day 3 and 37.09 % (from 3.37 to 4.62 kΩ) at day 5. The 3D7MG hydrogel exhibited superior therapeutic efficacy toward diabetic wound regeneration. The proliferation index value for 3D7MG-[DES]AZG and 3D7MG-[DES]AG were calculated 42.3 % and 58.6 %, respectively, while the control group exhibited a lower value of 37.8 %.

On-Line Measurement of Tracking Poses of Heliostats in Concentrated Solar Power Plants.

The tracking pose of heliostats directly affects the stability and working efficiency of concentrated solar power (CSP) plants. Due to occlusion, over-exposure, and uneven illumination caused by mirror reflection, traditional image processing algorithms showed poor performances on the detection and segmentation of heliostats, which impede vision-based 3D measurement of tracking poses of heliostats. To tackle this issue, object detection using deep learning neural networks are exploited. An improved neural network based on YOLO-v5 framework has been designed to solve the on-line detection problem of heliostats. The model achieves a recognition accuracy of 99.7% for the test set, outperforming traditional methods significantly. Based on segmented results, the corner points of each heliostat are found out using Hough Transform and line intersection methods. The 3D poses of each heliostat are then solved out based on the image coordinates of specific feature points and the camera model. Experimental and field test results demonstrate the feasibility of this hybrid approach, which provides a low-cost solution for the monitoring and measurement of tracking poses of the heliostats in CSP.

SOME GENRES AND FORMS OF EARLY MUSIC IN MODERN DOMESTIC PRACTICE

The presented scientific research analyzes the performance activities of contemporary artists specializing in harpsichord art at relevant festivals, among which the powerful annual Bach-fest (Sumy) and the Festival of Early Music in Lviv stand out. Throughout its history, the Bach-fest (Sumy) has brought together Ukrainian performers and leading artists from various countries in Europe, America, and Asia. This festival is practically a peer of the Ukrainian harpsichord school, with many musicians from Kyiv and Lviv honing their skills by performing on its stages and participating in its masterclasses. In turn, the Festival of Early Music in Lviv almost immediately became a creative platform for the establishment and development of historically informed performance in Ukraine. These musical meetings of like-minded individuals have become a point of intersection between the European and Ukrainian harpsichord schools, promoting active professional contacts among early music performers. It should be noted that the scholarly comprehension and artistic exploration of the genre panorama of Baroque keyboard music opens new creative perspectives for Ukrainian musicians.

Structural characterisation for the synthesis of large‐scale combined electric–gas networks

AbstractIn this paper, the authors present a methodology for building realistic synthetic test cases to model combined electric and natural gas infrastructure networks. Because these networks are synthetic, that is, fictitious, they are able to be freely shared; hence, they serve to support research and development in the area of coupled‐infrastructure analysis with large‐scale realistic test cases that do not contain non‐public information. We anchor our process for building these synthetic networks in a structural characterisation of actual electric and natural gas networks. Supply and demand nodes are geographically placed, based on a combination of publicly available information from several sources and a clustering‐based method to match the right fraction of each node type, taking into account the intersection points between the electric and gas grids. Then the networks are connected with pipelines and transmission lines using a systematic graph construction method, validated against network properties including degree distribution, clustering, graph diameter, and degree of planarity, along with operational validation to ensure the simulated solution is realistic. The methodology is demonstrated by creating and validating a test case with 6717 electric buses and 2451 gas nodes.

Re/Thinking Bioethics: Reproduction and Non-Reproduction in an Intersectional Bioethics’ Perspective

The article begins by reconstructing the main feminist bioethics perspective as a “new discourse” within the official bioethical discussion. It illustrates how the moral discussion and juridification have contributed to remove reproduction and non-reproduction from the personal and intimate context, reinventing them as a “states business”. This process framed these issues in terms of “duties”, “rights”, “family planning”, “demography”, and “population policy”. In this manner, law and morality have helped to reinforce a specific construct of fertility, motherhood, and family. By comparing two interrelated forms of Cross Border Reproductive Care (CBRC), concerning abortion and surrogacy, the article analyses how bioethical and legal frameworks – through their polarized and dichotomic discussion between law and morality – confirm and strengthen gender injustice in reproductive life. That comparison of cross-border travels highlights that surrogacy and abortion restrictions stem from a shared social and legal paradigm that relies on traditional gender roles and reveals how the stratification of reproduction is based on multiple discrimination along the lines of gender, race, and class. Finally, the article introduces an intersectional bioethics point of view on reproductive health to re-read the phenomena of non-reproductive and reproductive tourism and to propose a critique of the main global Northern feminist bioethical discourses and ethical-philosophical paradigms.

Magnetomechanical Behaviors of Hard-Magnetic Elastomer Membranes Placed in Uniform Magnetic Field.

This paper aims to develop a theoretical model for a viscoelastic hard-magnetic elastomer membrane (HMEM) actuated by pressure and uniform magnetic field. The HMEM is initially a flat, circular film with a fixed boundary. The HMEM undergoes nonlinear large deformations in the transverse direction. The viscoelastic behaviors are characterized by using a rheological model composed of a spring in parallel with a Maxwell unit. The governing equations for magneto-visco-hyperelastic membrane under the axisymmetric large deformation are constructed. The Zeeman energy, which is related to the magnetization of the HMEM and the magnetic flux density, is employed. The governing equations are solved by the shooting method and the improved Euler method. Several numerical examples are implemented by varying the magnitude of the pre-stretch, pressure, and applied magnetic field. Under different magnetic fields, field variables such as latitudinal stress exhibit distinct curves in the radial direction. It is observed that these varying curves intersect at a point. The position of the intersection point is independent of the applied magnetic field and only controlled by pressure and pre-stretch. On the left side of the intersection point, the field variables increase as magnetic field strength increases. However, on the other side, this trend is reversed. During viscoelastic evolution, one can find that the magnetic field can be used to modulate the instability behaviors of the HMEM. These findings may provide valuable insights into the design of the hard-magnetic elastomer membrane structures and actuators.

Comparison of local muscle oxygenation and whole-body VO2 during incremental exercise

The use of near-infrared spectroscopy (NIRS) in sports science has become increasingly important in the past few years (Perrey et al., 2024). One application is to determine thresholds from different NIRS parameters like oxygenated (O2Hb) or deoxygenated (HHb) hemoglobin to distinguish between hard and severe-intensity exercise (Caen et al., 2018). Such applications are frequently validated by comparison to established threshold determination concepts. However, it is not yet known which of the two parameters is more closely related to classical concepts. Therefore, the aim of this project was do analyze which NIRS parameter (oxygenated [O2Hb] or deoxygenated [HHb] hemoglobin) better reflects systemic behavior determined from ventilation (VE). Thirteen physically active participants (4 females, 9 males; mean age: 26.3 ± 4.4 years, height: 176.0 ± 10.3 cm, weight: 71.9 ± 9.3 kg) were included in the study. VE and NIRS data from a major locomotor muscle (vastus lateralis) during a step-incremental single leg cycle ergometer test were recorded. We used a custom MATLAB script to fit piecewise linear continuous functions by regression to estimate NIRS and VE thresholds. We used two distinct segments for NIRS data and three distinct segments for VE data. NIRS thresholds were defined as the point of intersection of the two segments in O2Hb and HHb signals, respectively. The ventilatory threshold was defined as the second increase in VE. We used a resampling strategy to reduce the impact of outliers or peculiar data distributions on threshold estimates. Thresholds from O2Hb and HHb in the active leg and VE were observed at 78.24%, 76.37%, and 84.15% of the maximum power achieved. Both O2Hb (r = 0.85, p &lt; 0.001) and HHb (r = 0.75, p = 0.0051) thresholds were significantly correlated, but mean values were significantly different (p &lt; 0.05) from the respiratory compensation point (RCP) mean value. Correlations between O2Hb and HHb values from the passive leg and the RCP values were in the same range (r = 0.88, p &lt; 0.001 and r = 0.79, p = 0.0023, respectively). The results indicate that, based on the correlations, O2Hb is slightly closer related to the second ventilatory threshold compared to HHb. The present study shows that thresholds from both NIRS parameters are closely related to the second ventilatory threshold which indicates a physiological relationship. However, thresholds cannot be used interchangeably as NIRS parameters derived from the working muscle appear earlier than systemic thresholds that demonstrate a delay in kinetics between the working muscle and the system.

Industry 5.0's pillars and Lean Six Sigma: mapping the current interrelationship and future research directions

PurposeIn the evolving landscape of Industry 5.0 (I5.0), which emphasises sustainability, human-centricity and resilience, mapping the current interrelationship and future research directions, the role of Lean Six Sigma (LSS) methodology remains underexplored. Our study addresses this gap by examining the potential of LSS to support I5.0 while identifying areas for further investigation.Design/methodology/approachThis study's multifaceted approach, which includes systematic literature review (SLR), bibliographic network analysis (BNA) and expert validation (EV), provides a holistic exploration of the interaction between LSS and I5.0 as the basis for well-founded conclusions.FindingsThe analysis yields several valuable insights. Firstly, it demonstrates the absence of a direct link between LSS and I5.0. Secondly, the substantial body of literature analysed establishes connections between LSS and its pillars. Thirdly, the analysis identifies points of intersection, difference and similarity between LSS and I5.0, highlighting the potential of LSS to facilitate implementation of I5.0 through its proven methodologies, continuous improvement culture, risk management, error learning, human–machine collaboration and training and skill development.Originality/valueThis study pioneers the effort to realise the latent potential of LSS in the context of I5.0. Its systematic identification of the synergies between these paradigms fills a critical gap in the literature and gives policymakers, managers and researchers a guide for informed decision-making to maximise the benefits of I5.0 for individuals, companies, society and the planet.

Convective heat transfer in porous channel with multi-layer fractures under Local thermal non-equilibrium condition

Based on Brinkman-extended-Darcy model and Local thermal non-equilibrium (LTNE) model, analytical solutions of velocity and temperature fields, pressure drop and Nusselt number of porous channels containing different number of fracture layers are obtained. The characteristics of fluid flow and heat transfer in multi-layer parallel fractured channels are further studied. Results show that for a single-layer or multi-layer fractured channel, the pressure drop changes sensitively at small hollow ratio and increases as the number of fracture layers increases with decreasing increase degree, but the pressure drop tends to be consistent regardless of the number of fracture layers when Darcy number is high. For small ratio of effective thermal conductivity, LTE model is valid regardless of Biot number, and the heat transfer intensity in multi-layer fractured channels is always higher than that in single-layer fractured channel at any hollow ratio, but the heat transfer intensity is still low. For large ratio of effective thermal conductivity, increasing Biot number or fracture layer number makes the Nusselt number increase under very small hollow ratio for both single and multiple fracture cases, and when both the ratio of effective thermal conductivity and Biot number are high, there is an intersection point occurs at hollow ratio near 0.1, which makes same heat transfer effect under different fracture numbers.

Weld seam object detection system based on the fusion of 2D images and 3D point clouds using interpretable neural networks

This study introduces a novel approach that addresses the limitations of existing methods by integrating 2D image processing with 3D point cloud analysis, enhanced by interpretable neural networks. Unlike traditional methods that rely on either 2D or 3D data alone, our approach leverages the complementary strengths of both data types to improve detection accuracy in environments adversely affected by welding spatter and smoke. Our system employs an improved Faster R-CNN model with a ResNet50 backbone for 2D image analysis, coupled with an innovative orthogonal plane intersection line extraction algorithm for 3D point cloud processing. By incorporating explainable components such as visualizable feature maps and a transparent region proposal network, we address the “black box” issue common in deep learning models.This architecture enables a more transparent decision-making process, providing technicians with necessary insights to understand and trust the system’s outputs. The Faster-RCNN structure is designed to break down the object detection process into distinct, understandable steps, from initial feature extraction to final bounding box refinement. This fusion of 2D-3D data analysis and interpretability not only improves detection performance but also sets a new standard for transparency and reliability in automated welding systems, facilitating wider adoption in industrial applications.

A comparative study of the efficacy of customized titanium plates versus conventional maxillary protraction in the treatment of skeletal class Ⅲ patients

Objective: To compare the clinical efficacy of customized titanium plate and conventional maxillary protraction treatment in patients with skeletal class Ⅲ malocclusion during growth spurt. Methods: During growth spurt, skeletal class Ⅲ patients with maxillary hypoplasia who were treated in the Department of Orthodontics, Capital Medical University School of Stomatology from August 2018 to July 2021 were prospectively enrolled. They were treated with maxillary protraction using customized titanium plates (customized titanium plate group) and conventional methods (conventional protraction group), respectively. Lateral cephalometric radiographs were collected before and after treatment for conventional cephalometric analysis, including SNA angle (angle between Sella, Nasion and A point), ANB angle (angle between A point, Nasion, and B point), FH-MP angle (mandibular plane angle), Y-axis angle, U1-L1 angle (upper to lower central incisor angle), U1-SN angle (upper incisor to SN plane angle), anterior and lower height, maxillary length, etc. The stable basicranial line (SBL) was used as the reference line to measure the distance from each reference point (ANS point, A point, Prn point, Sn point, UL point etc.) to the stable basicranial vertical line (VerT, the perpendicular line of the skull base line at the intersection point of the anterior wall of the sella image and the inferior edge of the anterior bed process). Paired t-tests were performed on the cephalometric data before and after maxillary protraction treatment in the two groups, and two independent samples t-tests were performed to compare the differences in the efficacy of the two maxillary protraction methods. Results: A total of 20 patients (9 males and 11 females), aged (10.8±1.3) years, were included in the personalized titanium plate group. A total of 20 patients (8 males and 12 females), aged (10.5±1.1) years, were included in the conventional protraction group. The SNA angle, ANB angle, FH-MP angle, Y-axis angle, anterior lower height, maxillary length, ANS-VerT distance, A-VerT distance, Prn-VerT distance, Sn-VerT distance, and UL-VerT distance were significantly higher than those before treatment in the two groups (P<0.05). The changes of SNA angle, ANB angle and A-VerT before and after treatment in the personalized titanium plate group [3.15°±2.28°, 4.64°±1.40°, (4.41±3.43) mm, respectively] were significantly higher than those in the traditional group [2.13°±2.69°, 2.81°±1.10°, (3.13±4.76) mm, respectively](P<0.05), and the changes of U1-L1 angle and U1-SN angle before and after treatment (-0.76°±7.42° and 1.74°±6.38°, respectively) was significantly lower than that of the control group (-5.14°±6.62° and 4.57°±5.24°, respectively, P<0.05). Conclusions: Maxillary protraction can effectively improve skeletal class Ⅲ relationships in growing patients. The linear measurements using the SBL line as a reference plane visualize the sagittal improvement in sagittal relationship after maxillary protraction. The customized titanium plate maxillary protraction treatment has a clear therapeutic effect on patients with skeletal class Ⅲ deformities, and its dental effect is relatively small.

Rescue ICSI Improved Cumulative Live Birth Rate for Cycles with Second Polar Body Extrusion Rate

ObjectiveTo determine the indications for early rescue intracytoplasmic sperm injection (ICSI) application. DesignA retrospective cohort study SubjectsThe study included 19,808 patients who underwent conventional in vitro fertilization (IVF) or rescue ICSI for their first cycles between February 2017 and December 2021. ExposureRescue ICSI cycles constituted the study group, where oocytes that had not extruded the second polar body 4-6 hours after insemination were rescued by ICSI. The control group consisted of conventional IVF cycles with no interventions to rescue oocytes without the second polar body. Generalized additive models (GAMs) were constructed to describe the relationship between the second polar body extrusion rate and cumulative live birth rate in conventional IVF and rescue ICSI cycles, respectively. The cutoff value of the second polar body extrusion rate guiding rescue ICSI application was determined from the intersection point of GAMs. Maternal age range applicable to rescue ICSI was further analyzed using the same method. Clinical outcomes were compared between conventional IVF and rescue ICSI cycles across different second polar body extrusion rate and maternal age subgroups. Main outcome measuresThe second polar body extrusion rate and maternal age range for rescue ICSI application, normal fertilization rate, and cumulative live birth rate. ResultsGAMs showed that the cutoff value for the second polar body extrusion rate about rescue ICSI application was 50%. When the rate <50%, normal fertilization rate and cumulative live birth rate (63.7% vs. 46.1%, OR: 1.609, 95% CI: 1.276-2.030) were significantly higher in rescue ICSI cycles than conventional IVF cycles. When the rate ≥50%, rescue ICSI cycles had similar normal fertilization rate and cumulative live birth rate compared to conventional IVF cycles. Further analysis on maternal age in cycles with second polar body extrusion rate <50% released that rescue ICSI cycles showed a higher cumulative live birth rate (67.7% vs. 48.3%, OR: 1.732, 95% CI: 1.361-2.202) than conventional IVF cycles for women aged < 38 years. ConclusionIVF cycles with second polar body extrusion rate <50% in women aged < 38 years was applicable to early rescue ICSI.