Horizontal And Vertical Research Articles

Prostate Cancer Stereotactic Body Radiation Therapy with Image-guided Radiation Therapy (IGRT) Technique with Three-Dimensional Transperineal Ultrasound for IGRT Tracking of the Prostate

Abstract Introduction Ultrahypofractionated radical radiotherapy for prostate cancer, also known as stereotactic body radiation therapy (SBRT), is an unprecedented modality of prostate radiotherapy and is still used very sparsely in Brazil. The use of fiducial implants and spacers may make it even more difficult to implement prostate SBRT on a large scale in Brazil. We describe a completely non-invasive technique for the treatment of localized prostate cancer with stereotactic body radiotherapy. Materials and Methods This is a case series study with 9 patients and 48 SBRT fractions analyzed. In our treatment protocol, we use the Elekta Versa-HD linear accelerator (Elekta, Stokholm, Sweden), a transperineal ultrasound (TPUS) with tracking and synchronization capabilities (Clarity 4D ultrasound system, Elekta), and the Monaco Planning System (Elekta). Displacements were measured in the three axes (lateral, longitudinal, and vertical). The discrepancy between the initial ultrasound location of the prostate and the location of the cone beam has also been documented. Results The mean displacements were 2.02 mm, 3.12 mm, and 2.93 mm for the lateral, longitudinal, and vertical directions, respectively. The data show that treatment was interrupted in 14 of the 48 treatment fractions (29.17%), 8 (57%) with displacements greater than 5 mm and 6 (43%) with displacements between 3 and 5 mm.The initial TPUS image-guided radiation therapy (IGRT) and its mean displacements for localization with the cone-beam computed tomography (CBCT) were 1.3 mm, 1.9 mm, and 1.5 mm, for the lateral, longitudinal, and vertical directions, respectively. Using van Herk formula, a margin of 7.3 mm in the lateral directions, 9.35 mm longitudinally, and 7.74 mm vertically, would be required Conclusion Here we describe an SBRT technique for prostate cancer that is completely non-invasive and allows for a high level of accuracy. Transperineal 3D ultrasound provides real-time position data to the prostate that can be used to gate the SBRT treatment, allowing for smaller, more personalized planning target volume (PTV) margins even without fiducial markers or spacers, which may be more applicable for low- and middle-income countries.

Aspect-Related Mechanical Properties of the Cortical Bone in the Third Metacarpal Bone of Mares

Complete fractures of the third metacarpal bone (MC III) diaphysis pose a significant clinical challenge, prompting advanced veterinary medicine to utilize constitutive and biomechanical modeling to better understand bone behavior. This study aims to compare the elastic modulus of the MC III cortical bone, supported by measurements of cortical bone thickness and relative density, across the dorsal, lateral, medial, and palmar aspects of the MC III, as well as to evaluate the cortical bone’s response to compressive forces applied in different directions. Given the bone structure can exhibit sex-related differences, MC III bones were isolated from six equine cadaver limbs collected exclusively from mares and imaged using computed tomography (CT) to measure thickness and density. Cortical bone samples were collected from the four aspects of the MC III and subjected to mechanical testing followed by the elastic modulus calculation. Bone thickness and elastic modulus varied across the MC III aspects. Thinner cortical bone on the palmar aspect coincided with a lower sample reaction force-based elastic modulus in the externo-internal direction and a lower axial compression force elastic modulus in the proximo-distal direction. Regardless of the MC III aspect, the cortical bone demonstrated greater resistance to compressive forces when loaded in the vertical plane than in the horizontal plane. The returning of different values in mechanical tests depending on the direction of loading may be attributed to the anisotropic behavior of the cortical bone, which may implicate the increased risk of complete fractures of the MC III diaphysis due to a kick from another horse or a fall, rather than from training or competition-related overload.

Multi-scale sparse convolution and point convolution adaptive fusion point cloud semantic segmentation method

Semantic segmentation of LIDAR point clouds is essential for autonomous driving. However, current methods often suffer from low segmentation accuracy and feature redundancy. To address these issues, this paper proposes a novel approach based on adaptive fusion of multi-scale sparse convolution and point convolution. First, addressing the drawbacks of redundant feature extraction with existing sparse 3D convolutions, we introduce an asymmetric importance of space locations (IoSL) sparse 3D convolution module. By prioritizing the importance of input feature positions, this module enhances the sparse learning performance of critical feature information. Additionally, it strengthens the extraction capability of intrinsic feature information in both vertical and horizontal directions. Second, to mitigate significant differences between single-type and single-scale features, we propose a multi-scale feature fusion cross-gating module. This module employs gating mechanisms to improve fusion accuracy between different scale receptive fields. It utilizes a cross self-attention mechanism to adapt to the unique propagation features of point features and voxels, enhancing feature fusion performance. Experimental comparisons and ablation studies conducted on the SemanticKITTI and nuScenes datasets validate the generality and effectiveness of the proposed approach. Compared with state-of-the-art methods, our approach significantly improves accuracy and robustness.

Relationships between tilt angles of rectus muscles and positions of rectus muscle pulleys in patients with sagging eye syndrome.

To examine the relationship between the rectus muscle (RM) angle and RM pulley displacement in patients with sagging eye syndrome (SES) without myopia. Retrospective cross-sectional case series. High-resolution quasi-coronal magnetic resonance imaging (MRI) data from 20 orbits of ten Japanese patients with SES but without high myopia were analyzed. The patients had no abduction deficiency. The RM angles were measured between the major axes of the horizontal and vertical RMs relative to the vertical and horizontal planes, respectively. The positions of the RM pulleys relative to the center of the globe were analyzed as previously described. The mean age of the patients was 75.8 ± 4.5 years (standard deviation). The average axial length was 23.6 ± 0.6 mm. The lateral rectus (LR) muscle angle (22 ± 6°) had moderate negative correlations with the inferior displacement of the inferior rectus (IR), superior rectus (SR), and LR pulleys (r =-0.63,-0.45, and-0.45, respectively); however, no change was observed in the medial rectus (MR) pulley (r =-0.41). No correlations were found between the angles of the SR (4 ± 8°), IR (-13 ± 8°), and MR (-1 ± 6°) muscles and the positions of the RM pulleys. Given the correlation between increased LR muscle angle and inferior displacement of adjacent RM pulleys in SES, the LR muscle angle may serve as a diagnostic clue, even when inferior displacement is not identifiable on MRI. Further confirmation in larger studies is warranted.

Dynamic Response Simulation for a Novel Single-Point Mooring Gravity-Type Deep-Water Net Cage Under Irregular Wave and Current

This study investigated the structural response characteristics of a novel single-point mooring gravity-type deep-water (SPM-GDW) net cage under irregular waves and currents. A hydrodynamic numerical model of the cage was created and validated through model experiments. Based on the validated cage model, the structural response characteristics such as cage motion response, mooring line forces, and floating collar stress were studied, considering the actual operating conditions in the target sea area. The response time history curves, wave height time history, and spectral density statistics were studied and compared. The results showed that the heave motion of the cage was consistent with wave elevation in the vertical direction and mainly influenced by wave conditions. The surge motion of the cage was closely related to the current, with a significant lag effect compared to wave elevation motion. Low-frequency loads under the combined action of waves and currents had a significant impact on the surge motion of the cage. In addition, the mooring line tension and pontoon stress were closely related to the wave elevation, with peak values of tension and stress occurring almost simultaneously with the peak wave elevation. However, the pontoon stress exhibited high-frequency response characteristics while satisfying the wave frequency response trend. It was found that the flow velocity had a significant impact on the spectral density of mooring line tension and pontoon stress in the low-frequency range, with an increase in spectral density values as the flow velocity increased. The structural response characteristics identified in this study provide a computational basis for the optimized design and analysis of single-point mooring gravity-type deep-water cages.

Study on time-frequency domain characteristics and cross-media communication of laser acoustic signals based on optical breakdown mechanism

Abstract Cross-media communication is a hot research issue at present. The use of sound waves generated by laser induced sound mechanism for cross-media communication is a new topic proposed in recent years. It is of great significance to study the characteristics of laser acoustic signal and the feasibility study for cross-media detection. The time-frequency characteristics and directivity of the laser induced sound signal are studied on the self-built experimental platform. The results show that the pulse duration of the laser acoustic signal is about 2 × 10−4 s, and the peak frequency is about 14.9 ± 0.75 kHz. And the signal strength perpendicular to the water surface is the weakest, so it has a good horizontal distance transmission ability. This paper verifies the detection system of trans-air-sea interface communication and trans-air-sea interface communication based on laser sound and conducts the communication experiment of laser acoustic signal. By modulating laser energy, the underwater acoustic signal is modulated in time domain, and the signal communication with 0-bit error rate of 8 bps within the meter is realized. The detection threshold of acoustic signal is calculated to be 44.9 dB re 1μpa after horizontal transmission of 1 km. The analysis and simulation of water surface micro-motion based on laser induced sound are carried out. The results show that the wave crest of water surface generated by laser acoustic signal through underwater reflection reaches the order of micron and can be detected by radar. The surface wave intensity is little affected by the depth of detection, so it could work in deep water. This study provides a certain experimental and theoretical basis for laser communication across the air and sea interface.

Large Bias in Matching Small Horizontal and Vertical Extents Separated in Depth in the Real World Is Similar for Upright and Supine Observers

The apparent sizes of horizontal and vertical lines show an anisotropy known as the horizontal vertical illusion (HVI) wherein vertical lines appear to be longer than their horizontal counterparts. Whereas a typical HVI comparing vertical and horizontal lines in a plane produces a 5–10% illusion, a much larger-scale illusion (15–25%) is often found for large objects in the real world, and this has been related to differential angular exaggerations in perceived elevation (vertical) and azimuthal (horizontal) direction. Recently supine observers in virtual environments were found to show larger exaggerations in perceived azimuth than upright observers. Here, 48 participants were tested in both supine and upright postures in an outdoor environment while matching fairly small physical extents in the real world. They adjusted the magnitude of the horizontal extent to perceptually match fairly small vertical poles (0.7–1.3 m tall) that were either presented at the same viewing distance as the matching extent or in a different depth plane, so that size at a distance had to be compared. Supine observers viewed the scene, as though upright, through a large mirror mounted overhead at 45° that was adjusted to approximate their normal eye height. When the matcher extent was at a different distance than the pole, horizontal extent matches typically exceeded the actual pole height by about 15% or more, whether the viewer was upright or supine. The average overestimation was only about 10% when the matching extent was at the same distance. Despite the similarity in performance across different postures for spatial matching, supine observers gave much higher explicit estimates of azimuthal direction than upright observers. However, although the observation of exaggeration in perceived azimuth for supine observers was replicated in a second study with 24 additional participants using a mirror with a smaller (more normal) aspect ratio, the magnitude of the exaggeration seemed to be greatly reduced when the field of view of the apparatus had a more typical aspect ratio. This suggests that the unusually large exaggeration of azimuth found in a previous report with supine observers may have been caused by the unusually large aspect ratio of the viewing apparatus used.

Seismic Performance Assessment of a Novel 2-D Base Isolation Device for Protecting Statues via Shaking Table Tests. The Case Study of the Statue of Goddess of Morgantina

ABSTRACT Recent seismic events in the Mediterranean have highlighted the vulnerability of historical monuments and museum artefacts to earthquakes. Although efforts have been made to protect buildings, attention to safeguarding artefacts within these structures has often been overlooked. Research on their protection mainly relies on analytical studies and small-scale models, with limited application in testing full-scale scenarios. The objective of this study is to assess the seismic performance of a novel 2-D base isolation device designed to protect museum artefacts, particularly statues. The device consists of a series of articulated quadrilateral mechanisms called Kinematic Steel Joint (KSJ), which enable a rigid base to move independently in both horizontal directions and exhibit pendulum-like behavior with the ability to re-center itself. The KSJ isolator has been extensively tested on a full-scale model using shaking tables of the L.E.D.A. Research Institute at the Kore University of Enna, Italy. To characterize it dynamically, the model has been subjected to random noises and earthquakes under various conditions and payload intensities. Subsequently, shake table tests have been conducted using a full-scale replica of the 2.24 meter high statue of the Goddess of Morgantina to demonstrate the effectiveness of the proposed seismic isolator in protecting statues during earthquakes.

Calculation of CT ideal screw path and safety angle before percutaneous sacroiliac screw placement

IntroductionPercutaneous sacroiliac screw placement is the main surgical approach to treat unstable posterior pelvic ring injuries. Intraoperative fluoroscopic imaging is an important part of safe sacroiliac screw placement. However, how to determine the right perspective view is challenging. We developed a trigonometric algorithm to verify how preoperative pelvic computed tomography (CT) can be used to predict ideal screw path and safety angle.Materials and methodsThe normal pelvic CT data of 30 volunteers from our hospital between September 2021 and June 2023 were collected, and analyzed and reconstructed using Materialise Mimics 21.0. The angle between the cross-sectional ideal screw path and the horizontal plane (∠α), the angles of the pelvic inlet and outlet on the sagittal plane (∠1, ∠2), and the insertion angles of virtual screws at the inlet and outlet (∠a, ∠b) were measured. The ideal insertion angles (∠A, ∠B) and safety angles of the screws at the pelvic inlet and outlet were calculated using trigonometric functions.ResultsThe virtual screw insertion angle ∠a of 30 pelvises measured at the inlet was 18.57 ± 4.33°, and the ideal screw angle ∠A calculated using trigonometric functions was 18.72 ± 4.71° (range, 13.84 ± 0.75°-23.36 ± 0.98°). The difference between the measurement and calculation was only 0.15 ± 0.19° and not significant. The angle ∠b of the virtual screw insertion measured at the outlet was 25.37 ± 5.13°, and the ideal screw angle ∠B calculated using trigonometric functions was 25.58 ± 4.93 ° (range, 19.02 ± 0.88°-31.31 ± 1.01°). The difference between the measurement and calculation was only 0.20 ± 0.13° and not significant. The distance e from the optimal screw insertion point to the vertical line through the anterior superior iliac spine is 32.34 ± 1.76 mm, and the distance f to the horizontal line through the posterior superior iliac spine is 28.61 ± 0.81 mm.ConclusionsDuring preoperative planning, trigonometric calculations were used to determine the ideal screw placement angles and safety angle at the inlet and outlet of the screw path. Combined with intraoperative C-arm fluoroscopy, individualized screw insertion can help orthopedic surgeons quickly and accurately obtain intraoperative images and accurately determine the direction of screw insertion.

The neural substrate of navigation using hydrostatic cues in goldfish.

Hydrostatic pressure is a global sensory cue exploited by fish to navigate in the vertical dimension. Unlike other navigational cues in the horizontal plane that usually require learning and memory to determine location, hydrostatic pressure signals the absolute position along the vertical axis. Recently, it was shown that fish can use hydrostatic signals to navigate. It remains unclear, however, which brain regions are involved in processing this signal. Here, we tested whether the dorsomedial and lateral parts of the pallium, two regions that were found to be critical in horizontal navigation, are also critical for hydrostatic cue detection in goldfish. The results show that lesions to both these regions cause fish performance to deteriorate to chance values, indicating that both regions play an important role in processing hydrostatic pressure cues. These findings thus contribute to the rapidly growing body of knowledge on teleost navigation in space.

Assessment of oil vertical diffusion in waters following an oil spill incident in an urban inland waterway.

Accidental oil spills can have a serious impact on water bodies. While most current studies have focused on waves, few have examined water flows, which represent the most common hydrodynamic environment in urban inland waterways. In this study, 12 hydrodynamic conditions were constructed, and the oil vertical diffusion characteristics under hydrodynamic conditions were investigated by measuring oil concentration and oil droplet size distribution at different depths. The main findings include: (1) Oil concentration decays exponentially along the vertical direction, the related parameters follow power and quadratic functions in relation to mean flow velocity, respectively; (2) Oil droplet size distribution was influenced by hydrodynamic characteristics, mean flow velocity was significantly positively correlated with its distribution range; (3) Oil droplet size distribution patterns at different depths were similar, in line with the characteristics of Rosin-Rammler distribution. Based on experimental data, a set of models was constructed to describe and predict the vertical distribution of oil concentration and oil droplet size distribution under hydrodynamic conditions. This study not only reveals the characteristics of oil vertical diffusion under hydrodynamic conditions, but also provides a quantitative framework for understanding the relevant features, which is helpful for the response to the oil spill accident in urban inland waterways.

A Multipath Mitigation Method for Significant Environmental Changes in Deformation Monitoring

A Multipath Mitigation Method for Significant Environmental Changes in Deformation Monitoring

Optimizing microstructure and minimizing defects in laser-arc hybrid additive manufacturing of Al-Cu alloy: the role of laser mode

Optimizing microstructure and minimizing defects in laser-arc hybrid additive manufacturing of Al-Cu alloy: the role of laser mode

Floquet topological phase transitions in 2D Su–Schrieffer–Heeger model: interplay between time reversal symmetry breaking and dimerization

Abstract In this paper, we present a theoretical analysis of 2D Su-Schrieffer-Heeger (SSH) model within the context
of Floquet topological insulators (FTIs). Generally speaking, FTIs are endowed with time reversal symmetry
(TRS) and its breaking by means of a time periodical process triggers a topological phase transition governed by
a Chern number. In our proposed model, the condition of TRS breaking is achieved by circularly polarized light
irradiation. The 2D SSH system represents actually a square lattice, where the first order neighbors hopping is
realized only on horizontal and vertical directions. One of the most important findings of our work is that the
TRS breaking is forbidden in the absence of diagonal hopping (between second order neighbors) and we give
a pure analytical proof. On the other hand, due to Peierls transition (PT) (dimerization), the 2D SSH model
undergoes a specific topological transition governed by a Zak phase. Going further, we pursue the interplay
between the TRS breaking and PT. We find thus an interesting topological frustration which is lifted upon PT.
The results are supported both analytically and numerically in terms of Chern numbers, spectral properties,
chiral edge states localization and Hall transport simulations. Our model is suitable not only for condensed
matter (materials), but also for cold gasses trapped in optical lattices or electric circuits.

Revealing the contribution of flame spread to vertical thermal runaway propagation for energy storage systems

Revealing the contribution of flame spread to vertical thermal runaway propagation for energy storage systems

Study of Variation Mechanisms of the Martian Diffuse Aurora Based on Monte Carlo Simulations and MAVEN Observations

AbstractMartian diffuse auroras are ultraviolet emissions spread across the nightside of Mars caused by solar energetic particles (SEP), both electrons and protons. The nightside structures of induced and crustal magnetic fields are expected to affect the diffuse auroral emission profiles caused by electrons, which is far from understood. Here we estimate magnetic field effects on emission based on a newly developed Monte Carlo model simulating collisions and electron cyclotron motions. Parameter surveys of the magnetic field intensity and dip angle (angle of magnetic field line from horizontal direction) under uniform magnetic field structure show that the effects of magnetic field dip angle on auroral altitude profiles are greater than those of magnetic field intensity. We then applied our model to the September 2017 diffuse aurora event using MAVEN SEP electron flux observations and neutral atmospheric profile from the Mars Climate Database as inputs. Comparison between horizontal and vertical magnetic field dip angle cases indicates that the horizontal dip angle case results in broader limb‐integrated auroral altitude profiles than the vertical case and enhances the auroral intensity at high altitudes (>75 km). The magnetic field structure can be one of the important factors in understanding the Martian diffuse auroras.

Hydraulic characteristics of effective sea lamprey barriers

Hydraulic characteristics of effective sea lamprey barriers

Comparative analysis on the normal vector features of the conventional inverted flame and ultra-lean residual flame

Residual behavior often appears near the flammability limit for lean premixed flames. Insight into it is beneficial to improve the lean premixed combustion performance further. Identifying the normal vector of the residual flame front plays a key role in revealing its structure and evaluating the weights of some main effects quantitatively. For the present residual flame with a high curvature, as the polynomial curve fitting method causes a noticeable error due to the Runge phenomenon, a non-equidistant central difference method is proposed. Subsequently, the normal vectors of the bluff-body stabilized residual flame and conventional inverted flame of 40%H2–60%CH4–air are obtained accurately and their differences are compared quantitatively. It is found that there are significant differences in the normal vector and flow structure features between the conventional inverted flame and residual flame behaviors. The normal vector of the conventional inverted flame always points at the upstream direction. However, the normal vector at the middle section of the residual flame front is almost parallel to the horizontal direction, and it points at the downstream direction next to the residual flame tip. In addition, the flow structure around the residual flame front is revealed. This is the first time the normal vector of the residual flame has been accurately visualized and the difference in normal vector feature between the residual flame and conventional inverted flame revealed. This work provides a universal and accurate method to identify the normal vector of the flame front and new insight into residual flame dynamics.

A dynamic analysis model for high-altitude steep slope jointless turnouts under the coupling effect of extreme temperature and actual vehicle load

This paper focuses on the difficulty in characterising the complex mechanical behaviour and deformation characteristics of jointless turnouts at high altitudes. Considering its unique characteristics of large altitude differences, large temperature variations, frequent traction actions, vast uninhabited regions, and high failures risks, a rigid-flexible coupling dynamics model of the vehicle-jointless turnout on steep slope under the combined effects of extreme temperatures and actual vehicle loads is established. The model considers the flexible deformations of the turnout along the longitudinal, lateral, and vertical directions, enabling precise representation of temperature loads and the elastic-plastic characteristics of the longitudinal resistance of fasteners within the multi-body dynamics. The research indicates that the coupling effect of extreme temperature and vehicle impact loads can cause the longitudinal resistance of fasteners to exhibit oscillatory effects during the plastic stage, leading to a significant increase in the peak values of longitudinal creep force, shear stress, and wear index of wheel rail, exacerbating rail damage and deterioration. Extreme temperature increases can induce an advancement in the wheel load transition position, with a forward shift value reaching 0.49 m when the temperature increases by 45°C, thereby intensifying wheel-rail impacts.

Effectiveness of Using Wire Rope Slings in Improving the Stability of Cantilever Retaining Walls

A slope is a land surface that slopes and forms a certain angle to a horizontal plane. In a place where there are two land surfaces of different heights, there will be forces that push so that the higher ground tends to move downwards which is called the potential force of gravity which causes landslides. Landslides on a slope can cause loss of life and property and can hamper the economy of an area. Cantilever walls are often used as retaining walls to avoid landslides. The cost used in the construction of cantilever wall retaining walls is quite expensive. For cost efficiency of the cantilever wall construction, it is necessary to use cantilever wall reinforcement using wire rope sling. In this study, cantilever wall retaining walls were modelled with or without the use of wire rope slings. The research location is Jl. Gelugur Rimbun, Ps x Kutalimbaru Kab. Deli Serdang. Based on the results of laboratory testing, the soil classification at the location is clay (CL). According to the analysis, the use of wire rope slings contributes to an increase in the factor of safety (FS) of overturning by 12.500% - 50.026%. While increasing the factor of safety (FS) sliding by 4.165% - 16.627%. An increase in the factor of safety (FS) bearing capacity of 17.222% - 36.109%. The greatest effect of the use of wire rope slings occurs in overturning stability by 50.026%. The use of wire rope slings can reduce the dimensions of cantilever retaining walls.