Change In Angle Research Articles

Long-term Clinical and Radiographic Results of Posteromedial Lateral Release for Neuromuscular Clubfoot Deformity.

Clubfoot occurs in up to 50% of patients with spina bifida (SB) and 90% with arthrogryposis (AR). Many of these patients with neuromuscular clubfoot deformity fail conservative casting and require surgery with posteromedial lateral release (PMLR). Limited data exist for the outcomes of PMLR in patients with SB and AR. Retrospective chart review was performed on PMLR in patients with SB and AR from January 2007 to June 2022, excluding those with follow-up <3 years or incomplete charts. Radiographic measurements were obtained pre-PMLR and post-PMLR when available. In total, 51 patients with 79 cases of clubfeet treated with PMLR at a tertiary children's hospital were identified. Of those, 35 patients with 54 cases of clubfeet treated with PMLR were analyzed, including 22 patients (29 feet) with SB and 13 patients (25 feet) with AR. In the SB cohort, 41% of feet required reoperation at an average of 4.6 years, and 76% of AR feet required reoperation at an average of 4.7 years post-PMLR. In addition, 21% of SB feet and 8% of AR feet required 2 or more reoperations. Talectomy was required post-PMLR in 24% of SB feet and 40% of AR feet at an average of 4.9 and 5.9 years, respectively. Younger age at time of PMLR was associated with significantly increased reoperation rates in AR (P=0.01). Greater change in calcaneus-fifth metatarsal angle after PMLR was associated with a future need for reoperation (P=0.047). Greater talo-first metatarsal angle after PMLR was associated with a future need for reoperations of any kind (P=0.040) in SB. Although PMLR remains a safe and successful treatment in the short term, many neuromuscular clubfeet will require additional procedures. Younger age and greater preoperative versus postoperative changes in calcaneus-fifth metatarsal and postoperative talo-first metatarsal angles were associated with increased reoperation rate. These results help orthopaedic surgeons counsel families about the long-term prognosis of clubfoot treatment in SB and AR. Level IV.

Optimized design of energy absorption of aluminum foam filled CFRP thin-walled square tube based on agent model

PurposeAluminum foam-filled thin-walled unit structures have received much attention for their excellent energy absorption properties. To improve the energy absorption effect of car energy absorption box under axial compression, this paper optimizes the fiber lay-up sequence, fiber angle and aluminum foam density of aluminum foam filled carbon fiber reinforced plastic (CFRP) thin-walled square tubes.Design/methodology/approachDesign of sample points required to construct the proxy model using design of experiments (DOE) method, and the data sample points of different models are obtained through Abaqus simulation and test. A double high-precision proxy model with the maximum specific energy absorption (SEA) and the minimum initial peak crash force (PCF) as the evaluation index is constructed based on the response surface function method. The NSGA-II multi-objective genetic algorithm was used to optimize the design parameters and obtain the optimal solution for the Pareto front, and the results were verified by using the multi-objective optimization toolbox in design-expert.FindingsThe results show that the optimal solution to the multi-objective optimization problem with the inclusion of the lay-up sequence is ρ = 0.5g/cm3 for a fiber lay-up angle varying in the range ±15–90° and an aluminum foam density varying in the range 0.2g/cm3-0.5g/cm3, with a lay-up method of [±87°/±16°/±15°/±89°]. The two optimization methods correspond to SEA and PCF errors of 2.109% and 4.1828%, respectively. The optimized SEA value is 18.2 J/g and the PCF value is 18,230 N. The optimized design reduces the peak impact force and increases the specific energy absorption, which improves the energy absorption effect of thin-walled energy-absorbing boxes for automobiles.Originality/valueIn this paper, the impact resistance of CFRP thin-walled square tubes filled with aluminum foam is optimized. Based on numerical simulations and experiments to obtain the sample point data for constructing the dual-agent model, we investigate the effect of filling with different densities of aluminum foam under the simultaneous change of fiber lay-up angle and order on its mechanical properties in this process, and carry out the multi-objective optimization design with NSGA-II algorithm.

Plasmonic Nanocomposite for Visible Light‐Modulated Bimorph‐Actuator

AbstractSoft actuators have great potential applications in sophisticated movement and sensitive devices due to their flexible nature, good interaction, and precise control. However, existing carbon‐based optical actuators are limited in their response under visible light irradiation. The limited visible light absorbance of the carbon nanostructure brought the metallic nanoparticle into the soft actuators that can absorb visible light. This study introduces a new type of plasmonic photothermal‐bimorph actuator, using graphene oxide (GO), reduced graphene oxide (rGO), and silver nanorods (Ag NRs) to overcome the limitations of traditional optical actuators. The bimorph film is actuated by visible and near‐infrared light stimuli with various power densities showing reversible deformation behavior. The actuator shows significant bending associated with a ≈50° change in bending angle under visible light irradiation with a response time of ≈5 ± 1 sec. Furthermore, a smart photo‐controlled non‐contact switch is fabricated based on photo‐thermal conversion properties, demonstrating perfect integration of plasmonic bimorph actuators. The density functional theory based molecular dynamics calculations provide an additional understanding of the bending of actuators under external stimulus. Using illustrative demonstrations of actuators, these results hint at a method for generating multipurpose visible light‐based soft robots, supporting a new approach to developing an optical locking system.

Turbulent flows past two elliptical cylinders in tandem arrangement: wake dynamics and aerodynamic characteristics

Abstract. This study investigates the aerodynamic phenomena of drafting, a common technique observed in various racing sports, by analyzing the wake dynamics behind two 2D elliptic cylinders placed in tandem. The research explores how the separation distance and the azimuthal angle between the cylinders affect turbulent wake patterns and aerodynamic coefficients. A numerical study was conducted using a RANS-based simulation, with findings validated through physical experiments in a wind tunnel. The study identifies six distinct wake dynamics: Wake states without vortex shedding, Single bluff body wake, Suppressed vortex shedding, Coupled vortex shedding, Anti-phase vortex shedding, and In-phase vortex shedding. These dynamics vary significantly with changes in separation ratio and angle of attack, highlighting the critical influence of these parameters on the wake behavior and aerodynamic performance. The results are presented in a phase diagram, illustrating the evolution of wake patterns across different conditions. This research fills existing knowledge gaps by providing a detailed analysis of the wake dynamics behind elliptic cylinders at high Reynolds numbers, with potential applications in improving aerodynamic strategies in various engineering and sporting contexts.

Non-Gaussian properties and their effects on extreme wind pressure of a 4:1 rectangular cylinder

This paper investigates the wind pressure characteristics of a 4:1 rectangular cylinder under 19 wind angles using a rigid model wind tunnel test, focusing on non-Gaussian properties and extreme wind pressure. The wind angle (α) varies from 0° to 90° and the Reynolds number (Re) ranges from 0.32 × 105 to 2.14 × 105. The spatial and statistical distributions of wind pressure, along with its non-Gaussian properties, are presented. Detailed analyses of these characteristics are provided. The peak factor of wind pressure was calculated using the modified Hermite method. The results indicate that the skewness and kurtosis of the windward region of the 4:1 rectangular cylinder remain relatively unchanged with varying wind angles. In contrast, the skewness and kurtosis in the separation and wake zones are significantly influenced by changes in the wind angle. Most wind pressures on the 4:1 rectangular cylinder exhibit negative bias and a softening process. The non-Gaussian properties are most prominent at the corner of the wake zone. The peak factor of 2.5 (used in Chinese code) or peak factor g,G based on Gaussian processes on the separation and wake zones of interest are much smaller than the peak factors g,NG calculated based on the modified Hermite method. Ignoring non-Gaussian properties underestimates extreme wind pressures by at least 20%–30%. Therefore, non-Gaussian properties must be considered when calculating wind pressure extremes for similar rectangular structures. Additionally, the peak factor value in the Chinese code should be increased appropriately to ensure structural safety.

Modification and mechanistic study of fluid/fluid and carbonate rock/fluid interfaces using a glycolipid biosurfactant from an indigenous strain of Gordonia terrae for MEOR applications

To clarify the mechanism of the interface behavior between carbonate surface/biosurfactant solution/oil systems, the interfacial tension (IFT), surface wettability, spreading coefficient (SC), and capillary number were investigated with regard to the synergistic effects of a biosurfactant from an indigenous Gordonia terrae strain (isolated from an Iranian oil reservoir), formation water salinity, and pH using response surface methodology (RSM-CCD). According to the analysis of variance results, the process effectively depicted by the quadratic model demonstrated statistical significance in terms of the responses of IFT, wettability alteration, and SC, which were significantly affected by biosurfactant concentration. The optimal conditions were 0.260 g/L biosurfactant, 36.202 g/L salinity, and a pH of 5.9. Accordingly, the quadratic model was verified using the estimated optimal parameters, thereby confirming the accuracy of the model in which a strongly water-wet surface (contact angle change from 159° to 31°) and IFT reduction (from 23.96 to 1.26 mN/m) resulted in an SC of near-zero value (−0.18) and 25 % recovery of oil during the imbibition experiments after secondary water flooding. The desorption of the polar components of crude oil from the dolomite rock surface was also investigated through determining the un-coverage ratios of the elements using energy dispersive X-ray microanalysis and characterization. Although the solutions containing biosurfactants contributed to the alteration of the rock surface wettability, their performance strongly depended on the pH and salinity, resulting in different desorption ratios. The desorption of approximately 40 % of the adsorbed organic compounds from the carbonate surface was a critical limiting factor affecting the surface properties of the rock, and was responsible for altering the wettability to water-wet conditions. The results of this study are expected to contribute to the development of effective biosurfactant-flooding techniques for MEOR.

Argon Ion Implantation as a Method of Modifying the Surface Properties of Wood–Plastic Composites

Wood–plastic composites (WPCs) combine the properties of plastics and lignocellulosic fillers. A particular limitation in their use is usually a hydrophobic, poorly wettable surface. The surface properties of materials can be modified using ion implantation. The research involved using composites based on polyethylene (PE) filled with sawdust or bark (40%, 50%, and 60%). Their surfaces were modified by argon ion implantation in three fluencies (1 × 1015, 1 × 1016, and 1 × 1017 cm−2) at an accelerating voltage of 60 kV. Changes in the wettability, surface energy, and surface colour of the WPCs were analysed. It was shown that argon ion implantation affects the distinct colour change in the WPC surface. The nature of the colour changes depends on the filler used. Implantation also affects the colour balance between the individual variants. Implantation of the WPC surface with argon ions resulted in a decrease in the wetting angle. In most of the variants tested, the most significant effect on the wetting angle changes was the ion fluence of 1 × 1017 cm−2. Implantation of the WPC surface also increased the surface free energy of the composites. The highest surface free energy values were also recorded for the argon ion fluence of 1 × 1017 cm−2.

Traction drive simulations when starting an electric locomotive series ŽS 444 on the railway tracks of Serbia

The manuscript presents and describes the Model in Matlab-simulink, which allows to display the time change of the firing angle of the thyristor of the single-phase rectifier, the mean value of the voltage, the armature current and the speed of the electric motor during the start-up of the electric locomotive ŽS 444 series for different given mechanically loaded and reference speeds of traction electric motors. The model makes it possible to establish the desired reference speed change ramps for different reference speeds and mechanical loads from +250 rpm, i.e., the maximum current of the electric motor armature up to 1250 A.

Comparison of Compression of Occlusal Splint Materials: Laboratory Mechanical Analysis

Objective: To perform a compression test to fill the gap in the literature, assess the change in the construction angle (0º, 45º, 90º) as well as investigate physical and microstructural characteristics. Theoretical Framework: Comparisons of compression tests of occlusal splint materials printed in 3D are not described in the literature, which makes informed decision making on the choice of materials complicated. Method: The materials printed in 3D using the SLA method were resins. After printing, the materials were submitted to compression (calculating the Poisson coefficient), shore hardness and density tests. Results and Discussion: Dima® Print Ortho achieved the best results in terms of compression strength and maximum deformation in the vertical position (90º) in comparison to the other materials, followed by Self BioPrint Splint Hard, PriZma 3D Bio Splint and Cosmos Splint. Research Implications: Three-dimensional devices through additive fabrication can be used in the treatment of bruxism. The position to obtain greater compression strength is vertically at 90º. Originality/Value: This study contributes to the literature by demonstrating the efficacy of 3D printing of occlusal devices using the resin polymerization method, highlighting the superior dimensional accuracy and mechanical properties of the materials employed. Furthermore, it addresses the sustainability of the process by promoting material waste reduction during fabrication. These findings have significant implications for optimizing the production of occlusal devices in clinical settings.

Design player robot badminton-based microcontroller

Robots are one of the technologies that is currently advancing quickly. Generally speaking, a robot's movement is similar to that of an automobile; it can only move forward, backward, left, and right. Because the movement is controlled by these movements, it is thought that the robot's movement is extremely restricted to the left and right directions. solely with the front wheels. As a result, a robot was developed in this study that can control sliding motions to the left and right utilizing omniwheels on its front and back wheels. Badminton is a sport involving rackets that is played by two people or two opposing pairs. Robotic badminton players are employed as a substitute for human trainers in the training process, particularly for service and drive motions. With the use of a wireless joystick, the robot's ATMega 8535 microprocessor controls both the robot's direction of motion and the movement of its racket. Using a double acting pneumatic cylinder that requires 7 bar of air pressure, the robot service arm uses the compressor's air pressure. The average time it takes for the racket to strike the ball at 7 bar of wind pressure is 00:5.2 seconds. The time it takes for the ball to fall onto the racket in the absence of wind pressure is 00:28 seconds on average. A difference value of 00:22.7 seconds is acquired, and this value will be utilized as the programming reference delay. The robot encounters a slope with an average angle change of 7º when moving forward, an average angle change of 10º when moving backward, an average angle change of 5.2º when moving right, and an average angle change of 3º when moving left. The uneven field surface causes the robot to move at a slope, which modifies the speed of the motor on the wheels

Substantiation of rational design parameters of a crusher with two movable jaws

Purpose. Design engineering of the mechanism of a two-jaw crusher with a compound motion of the jaws, which ensures a change in the angle of gripping of pieces of material within a very small range. Methodology. In the work, a theoretical study on the fourth-class lever mechanism, as the basis of a two-jaw crusher, was performed using the Mathcad 15 software. The study was performed on a vector representation of the links of the hinged mechanism. The development and analysis of constructive solutions were performed using the Autocad software product, which reduces the risk of errors and increases the quality of the design process. Findings. The paper theoretically determines the rational geometric parameters of the two-jaw crusher with the optimal value of the nip angle, whose crushing chamber is formed by the closed loop circuit of the flat fourth-class lever mechanism and proposes a new constructive solution of the mechanism for adjusting the crusher opening with two movable jaws and the bottom mounting of eccentric nodes. The developed device in the form of separate blocks is made with the possibility of their simple assembly and disassembly, which ensures the rate and quality of replacing lining plates or surfacing restoration of the worn working surface of the jaws. The relative movement of the jaws ensures the crushing of pieces of material with the required crushing coefficient. The geometric parameters were obtained by the method of kinematic synthesis. The geometric parameters of the crushing chamber of the two-jaw crusher were determined theoretically; the dependence was obtained of the change in the nip angle on the height of the movable jaw over a period of movement and the change in the compression stroke, which ensures the force interaction of the working surface of the jaws with the material. Originality. It is proved that the quadrilateral closed circuit of the fourth-class lever mechanism can be used as a crushing chamber of a two-jaw crusher. Two links of a closed circuit operate as jaws which break pieces of material. At the same time, the nip angle can vary within fairly narrow limits, ensuring the optimality of the crushing process. It was established that the considered option of the fourth-class six-link mechanism geometry has only two folds. An algorithm is presented for searching for assemblies with the purpose of identifying those that are closely adjacent. Practical value. The results of the conducted research provide the theoretical background and the algorithm for determining the optimal parameters of a two-jaw crusher which can be used at the stage of designing similar crushers. The developed design solution for adjusting the crusher opening expands the scope of application of double-jaw crushers. The obtained dependences of the change in the angle of inclination and the working surface of the jaw over a period make it possible to develop a rational mode of crushing the material

The thrust balance model during the dragonfly hovering flight.

In recent years, the micro air vehicle (MAV) oscillations caused by thrust imbalances have received more attention. This paper proposes a dual-wing thrust balance model (DTBM) that can solve the above problem by iterating the modified rotation angle formula. The core control parameter of the DTBM model is the au angle, which refers to the angle between the wing surface and the stroke plane at the mid-stroke position during the upstroke. For each degree change in the au angle, the range of variation in the dimensionless average thrust coefficient is between 0.0225 and 0.0268. A thrust coefficient of 0.0225 causes the dragonfly to move forward by 9.037 cm in one second, which is equivalent to 1.29 times its body length. By using DTBM, the average thrust coefficient can be reduced to below 0.001 in just a few iterations. No matter how complex the motion pattern is, the DTBM can achieve thrust balance within 0.278 seconds. Through our research, when selecting the deviation angle motion of real dragonflies, the dual-wing au angles exhibit a highly linear correlation with wing spacing, called linear motion. In contrast, the nonlinear variation of the au angle appears in the hindwing of the no-deviation motion and the forewing of the elliptical deviation motion. All of the nonlinear changes are referred to as nonlinear motion. Nonlinear variation of the au angle arises from larger disturbances of the lateral force during the upstroke. The stronger lateral force is closely related to the flapping trajectory. When the flapping trajectory causes the dual-wing to closely approach each other in the mid-stroke, a continuous positive pressure zone forms between the dual-wing. The collision of the leading-edge vortex and the shedding of the trailing-edge vortex is the special flow field structure in the nonlinear motion. Guided by the DTBM, future designs of MAVs will be able to better achieve thrust balance during hovering flight, requiring only the embedding of the iteration algorithm and prediction function of the DTBM in the internal chip.

Ten-Year Follow-Up After Descemet Membrane Endothelial Keratoplasty.

To examine clinical results up to 10 years after Descemet Membrane Endothelial Keratoplasty (DMEK) and Triple-DMEK. Prospective study including 201 eyes, of which 54 eyes [38 DMEKs and 16 Triple-DMEKs; Fuchs endothelial dystrophy (n = 45), pseudophakic bullous keratopathy (n = 9)] reached the minimum follow-up of 5 years and were followed up for up to 10 years. We evaluated best-corrected visual acuity (BCVA, logarithm of the minimum angle of resolution [logMAR]), endothelial cell density (ECD, cells/mm2), minimal central corneal thickness (CCT, μm), central retinal thickness (μm), rebubbling, graft survival and re-DMEK rate, chamber angle alterations, and incidence of glaucoma. Fifty-four eyes had a 5-year and 37 eyes an 8- to 10-year follow-up. Mean follow-up was 94.4 ± 12.1 months. Best-corrected visual acuity increased from 0.6 ± 0.3 logMAR to 0.1 ± 0.2 logMAR at 6 months (P ≤ 0.001) and was 539 ± 54 μm at long term. Endothelial cell density decreased from 2488 ± 320.9 (donor) to 980.1 ± 437 cells/mm2 with an average ECD loss/year of 4% and did not correlate with BCVA. Central corneal thickness decreased from 596.9 ± 82.2 μm to 498.6 ± 24.3 μm at 12 months (P ≤ 0.001) and remained stable (P = 1.000). Mean rebubbling rate was 0.3 ± 0.5/eye and did not correlate with BCVA. Eight eyes (14.8%) received at least 1 rebubbling. Primary graft failure/rejection rate was 1.5%/0% within the first postoperative year, and secondary graft failure rate was 12.4% at 7 years. Eight eyes (preoperative n = 3, de novo n = 5) had open-angle glaucoma without chamber angle changes (14.8%, P ≤ 0.001). Although ECD decreases continuously in the long-term follow-up, excellent visual acuity can be preserved 10 years after DMEK and Triple-DMEK. The final outcome can be estimated 6 months after surgery.

Behaviour of paddled energy-absorbing rockbolts under complex loading laboratory conditions

Since their introduction in 2010, paddled energy-absorbing rockbolts have been widely used in seismically active hard rock mines. This paper provides new data and reviews previous work to quantify the performance of paddled energy-absorbing rockbolts under controlled laboratory conditions. Of significance is the realization that the typical split location in impact tests, at the centre between two paddle anchor points can at best provide an upper limit value. This inherent variability in performance under different testing configurations should be acknowledged and taken into consideration in the design of ground support in seismic conditions. This paper discusses the reduction in capacity of paddled rockbolts as a function of loading angle from a maximum value during axial tests (0° loading angle) to the lowest value during pure shear (loading angle of 90°). A significant reduction in displacement capacity is observed as the loading angle changes between axial (0°) and 40°. Beyond a 40° loading angle up to shear (90°) loading the reduction in displacement capacity is less significant. Due to the variances in the capacity observed through the variance of the testing configuration: loading mechanism, direction of loading, location / presence of a discontinuity, it must be recognized that results from laboratory-based testing are not independent of the testing configuration. This should be acknowledged when extrapolating anticipated performance in the field.

Numerical Investigation of the Slope Stability in the Waste Dumps of Romanian Lignite Open-Pit Mines Using the Shear Strength Reduction Method

Open-pit mining generates significant amounts of waste material, leading to the formation of large waste dumps that pose environmental risks such as land degradation and potential slope failures. The paper presents a stability analysis of waste dump slopes in open-pit mining, focusing on the Motru coalfield in Romania. To assess the stability of these dumps, the study employs the Shear Strength Reduction Method (SSRM) implemented in the COMSOL Multiphysics version 6 software, considering both associative and non-associative plasticity models. (1) Various slope angles were analyzed, and the Factor of Safety (FoS) was calculated, showing that the FoS decreases as the slope angle increases. (2) The study also demonstrates that the use of non-associative plasticity leads to lower FoS values compared to associative plasticity. (3) The results are visualized through 2D and 3D models, highlighting failure surfaces and displacement patterns, which offer insight into the rock mass behavior prior to failure. (4) The research also emphasizes the effectiveness of numerical modeling in geotechnical assessments of stability. (5) The results suggest that a non-associative flow rule should be adopted for slope stability analysis. (7) Quantitative results are obtained, with small variations compared to those obtained by LEM. (6) Dilatation angle, soil moduli, or domain changes cause differences of just a few percent and are not critical for the use of the SSRM in engineering.

Electromagnetic bone segment tracking in multiplanar osteotomies: A saw bone study.

Computer assisted orthopedic surgery is used to improve precision. Electro-magnetic tracking has been shown to improve precision in mono-planar derotational osteotomies. However, studies are lacking to investigate its use in multiplanar osteotomies. For this purpose, 60 complex (derotation and extension) osteotomies were performed in standardized sawbones. Correction amount was randomly planned before the procedures. In 30 bones, the amount of correction was determined intraoperatively using conventional goniometric measurement while in the other 30 bones electro-magnetic tracking was used to guide the amount of correction. CT-scans were done before and after the procedures in all bones and the amount of correction was determined to compare the precision of the two techniques. Electromagnetic tracking resulted in a precision of 2.25° ± 1.77° for derotation and 1.38° ± 1.29° for extension, while precision for the conventional method was significantly lower. There was a significant relationship between goniometer measurement deviation and the absolute angle change for derotation and extension measurements with larger deviations for greater angle changes. For the electro-magnetic tracking, this correlation was observed only for derotation measurement. Electro-magnetic tracking represents an accurate method to control complex, multiplanar corrective osteotomies with superior precision in comparison to conventional goniometric measurement. Further research is needed to investigate the in-vivo accuracy and the effects on clinical outcome.

Understanding abscisic acid-mediated stress signaling to affect rice development under stress

IntroductionRice is a vital staple food for many countries, and its yield is known to be significantly affected by various abiotic stresses, which are expected to intensify with climate change, posing a threat to global food security. Abscisic acid (ABA), a crucial plant growth regulator, plays a crucial role in plant responses to these abiotic stresses. It influences several processes, such as seed dormancy, leaf gas exchange, reactive oxygen species (ROS) scavenging, ion toxicity reduction, and root elongation, all of which contribute to enhancing plant survival under stress.MethodsThis article reviews recent research on ABA-mediated gene responses and expressions involved in rice plant architecture and its response to abiotic stress.Results and discussionAbscisic acid responses were primarily driven by changes in gene expression. Expression analyses of the gene related to ABA biosynthesis or catabolism indicated several changes in plant architecture, such as changes in leaf angle, delayed flowering, and modifications in growth regulators. Additionally, tolerance-related mechanisms, such as increased ROS scavenging, reduced membrane leakage, and vacuolar compartmentation of toxic radicals, were activated under single or multiple stress conditions. While these adaptations may improve plant survival and yield sustainability under stress, they may not necessarily enhance yield potential in environments affected by drought, salinity, or heat stress. ABA expression was also associated with improved pollen viability, grain-filling potential, and seed setting under abiotic stresses such as heat, which could enhance seed yield in such challenging environments.

Effect of body mass index on quadriceps angle and tibial torsion in school-aged children

BackgroundThe prevalence of excessive body mass (BMI) is increasing in pediatric population. Accordingly, the number of musculoskeletal problems in this population is also likely to increase. The quadriceps angle (Q-angle) is a clinical measure used to measure knee alignment in relation to the hip, femur, and tibia, as well as evaluating alignment of the patella. Tibial torsion (T.T) is an important morphological feature of human tibia. The aim of that study was to study the relationship between the Q-angle and TT in children 8 to 12 years old, the effect of BMI on Q-angle and T.T, and the difference in Q-angle and TT between dominant and non-dominant side.Results“Seventy-five children from primary schools” were enrolled in the study and allocated into 3 groups (25 subjects in each group), according to BMI: group I (normal weight = 25), group II (overweight = 25), and group III (obese = 25). The mean value of age of groups I, II, and III was 10.35 ± 1, 10.74 ± 1.2, and 10.17 ± 1.18 years respectively; the mean value of weight was 29.88 ± 3.94, 43.68 ± 6.55, and 50.06 ± 10.44 kg respectively; the mean value of height was 135.28 ± 7.63, 143.2 ± 8.85, and 140.72 ± 9.3 cm respectively; and the mean value of BMI was 16.22 ± 1, 21.18 ± 1.4, and 25.17 ± 2.67 kg/m2. The number (%) of boys in groups I, II, and III was 15 (60%), 18 (72%), and 17 (68%) respectively and of girls was 10 (40%), 7 (28%), and 8 (32%) respectively.The significant values were Q-angle and TT. Data were expressed as mean ± SD. ANOVA was used to compare between subjects’ characteristics of the groups. Kolmogorov-Smirnov test was used for testing normality of data distribution. One-way MANOVA was used to compare parametric variables (Q-angle and TT) between the two groups. Compared with normal weight children, there was statistically significant increase in Q-angle and TT angle in overweight and obese children.ConclusionAny change in BMI would eventually lead to change in both Q-angle and TT angle. The greater the BMI values, the greater the values of Q-angle and TT angle.

The feasibility of double stent strategy in left main true bifurcation with small and large angle change between diastole and systole: The Milan and New-Tokyo (MITO) registry.

Provisional single stenting strategy (PSS) is a default strategy for percutaneous coronary intervention (PCI) of unprotected left main distal bifurcation lesions (ULMD). Previous study reported that a bifurcation angle change (BAC) between end diastole and systole was associated with outcomes after PCI with double stent strategy (DSS) for ULMD. However, there are no data comparing outcomes after PCI with PSS versus DSS according the degree of BAC. We evaluated outcomes after PCI with PSS versus DSS for true ULMD with small and large BAC. We identified 566 patients with true ULMD underwent PCI in three high-volume centers. We calculated the BAC in ULMD between end-diastole and systole before stenting with 2-dimensional quantitative coronary angiographic assessment. We defined small (BAC < 7.0°) and large BAC (≥7.0°) group. We compared clinical outcomes after PCI with PSS versus DSS in each cohort after propensity score adjustment. The primary endpoint was target-lesion failure (TLF), which was defined as a composite of cardiac death, target lesion revascularization, and myocardial infarction. In small BAC cohort, TLF rate was significantly lower in DSS group than in PSS group (12.5% vs. 20.1%, adjusted HR 0.45; 95% CI, 0.26-0.79; p = 0.006). In contrast, in large BAC cohort, TLF rate was significantly higher in DSS group than in PSS group (54.9% vs. 29.0%, adjusted HR 2.25; 95% CI, 1.50-3.38; p < 0.001). The TLF rate after PCI with DSS was significantly lower in true ULMD with small BAC compared to PSS even after propensity score adjustment. In contrast, it was significantly higher in those with large BAC.

Short-term changes in the trabecular iris angle and anterior chamber during wear of scleral lenses with different diameters

ABSTRACT Clinical relevance Scleral lens (SL) compression on the conjunctiva/episclera during wear may alter adjacent structures related to aqueous humour drainage. Background The aim of this work was to assess short-term changes in the four quadrants of trabecular iris angle (TIA) and anterior chamber parameters during SL wear, using anterior segment optical coherence tomography (AS-OCT). Methods Prospective study was conducted involving 16 healthy subjects with a mean age of 28 ± 5 years. Two SL of diameter 15.80 mm (L1) and 16.80 mm (L2) with the same parameters were used for 2 hours in different days. The central fluid reservoir (FR), the TIA in superior, inferior, nasal, temporal quadrants, and anterior chamber parameters; anterior chamber depth (ACD), anterior chamber width (ACW), anterior chamber area (ACAr) and anterior chamber volume (ACV) were measured with AS-OCT. These measurements were performed immediately after SL application (0 h), one hour (1 h) and two hours (2 h) of SL wear. Results TIA decreases significantly in the superior quadrant at 2 hours of L2 wear (−5.19 ± 7.79º) (p = 0.04). In this sector, differences were also observed between the changes induced by both lenses during the 2 hours of wear (p = 0.04) and between first and second hours of wear (p = 0.04). ACD was significantly lower with L1 (−0.09 ± 0.14 mm) relative to L2 (0.00 ± 0.06 mm) between immediately after the application and 2 hours of wear (p = 0.02). A significant reduction in ACAr at 1 hour (−0.65 ± 0.75 mm2) (p = 0.01) and 2 hours of wear (−0.81 ± 1.15 mm2) (p = 0.04), as well as in ACW at 2 hours (−0.11 ± 0.14 mm) (p = 0.02) compared to immediately after application of L1 was found. Conclusion Small changes in TIA and anterior chamber occur during two hours of SL wear, but these changes are of limited clinical relevance in healthy subjects.