Direction Of Displacement Research Articles

Superficial fascia displacement in cervical flexion: differentiating myofascial pain syndrome, a cross-sectional study.

Myofascial pain syndrome (MPS) is primarily characterized by myofascial trigger points related to fascial adhesions. MPS hinders fascial flexibility and mobility, leading to myofascial limitations, dysfunctional movement, and limitation of motion (LOM). This study determined the association of age, sex, type of work, symptom chronicity, symptom laterality, cervical LOM, altered direction of fascial displacement, and magnitude of superficial fascial displacement during active cervical flexion with the clinical diagnosis of MPS. A cross-sectional study selectively included MPS and non-MPS participants from different workplaces from January to October 2019. The MPS group exhibited clinical symptoms like tender spots, recognized pain patterns, and local twitch response upon palpation, often accompanied by cervical LOM. The non-MPS group lacked these symptoms, and those with certain pre-existing conditions or recent physiotherapy were not part of the study. Participants performed cervical active range of motion (AROM) while a sonographer recorded superficial fascial displacement utilizing ultrasound, which was later analyzed by three physiotherapists with the Tracker. Aiming for a multiple regression R-squared of 0.2, the target was 384 participants to account for a 20 % dropout, resulting in 307 participants after attrition. To explore the relationships between MPS and various factors, logistic regression models, rigorously tested for reliability and validity, were utilized. In the study, there were 192 participants with MPS and 137 without MPS. The median ages were 33 years for the non-MPS group and 38 years for the MPS group. The adjusted model found significant links for sex (odds ratio [OR]=2.63, p<0.01), symptom chronicity (OR=8.28, p<0.01), and cervical LOM (OR=3.77, p=0.01). However, age and the presence of nodules/taut bands were not statistically significant (p>0.05). Also, the type of work, the direction of fascial displacement, and the difference in superficial fascial displacement during cervical flexion did not show a significant association with the clinical diagnosis of MPS (p>0.05). The adjusted model had a sensitivity of 73.80 % and a specificity of 81.34 %, correctly identifying 84.66 % of positive cases and 68.99 % of negative ones, resulting in an overall accuracy of 76.95 % in predicting MPS. We provided an in-depth examination of MPS, identifying sex, duration of symptoms, and cervical LOM as significant predictive factors in its diagnosis. The study emphasizes the critical role of these variables in the accurate diagnosis of MPS, while delineating the comparatively minimal diagnostic value of other factors such as age, type of occupation, presence of nodules or taut bands, and variations in fascial displacement. This study underscores the imperative for further scholarly inquiry into the role of fascial involvement in musculoskeletal disorders, with the objective of enhancing both the theoretical understanding and diagnostic practices in this medical domain.

Influence of Ali Al -Gharbi Earthquake on Braced Excavation in Silty Clay Soil (Numerical Study)

The design of the braced excavation system is one of the important and necessary matters for the implementation of various projects. The braced excavation system is used to support excavations in temporary projects, so there are shortcomings in the study of this aspect, although sometimes there are many projects that take long periods of time especially the projects of underground tunnels and high buildings. This was the main reason for the study. Therefore, the possibility of exposing the drilling system to earthquakes is great, especially in seismically active areas. If the drilling system is exposed to an earthquake, it can cause great human and material losses, so it must be designed against earthquakes so that ensure complete collapse and failure does not occur. This study aims to investigate the behavior of braced excavations under the influence of the Ali Al-Gharbi earthquake in both x- and y- directions. A numerical study is carried out on braced excavation system of (14×6) m and depth 9m using software Plaxis 3D. The braced excavation system consists of three type of bracing system with three levels of strut and wales connected with sheet pile wall to support sides of excavation and prevent them from collapsing. The results of study showed that the horizontal displacement of braced excavation system is (100-155) % more than vertical displacement (settlement) with seismic time when system is subjected to Ali Al-Gharbi earthquake in both directions with the other factors remaining constant. The stiffness of sheet pile wall also play an important role increases and decreases lateral displacement in both direction. Also, the results showed that the movement of of braced excavation system depends on several factors like as type of soil, time acceleration and the direction of earthquake. Settlement of Ali Al-Gharbi earthquake in Y- direction is 13% more than in X-direction.

Design of an Optical Head with Two Phase-Shifted Interference Signals for Direction Detection of Small Displacement in an Absolute Surface Encoder

This paper presents the design and construction of a new optical head with two phase-shifted interference signals in an absolute surface encoder by using a mode-locked femtosecond laser. A series of discrete absolute positions of the scale grating is obtained from a series of peak wavelengths of the spectrum of the +1st- or -1st-order diffracted beam. The two beams at a specific wavelength λi interfere with each other to generate an incremental interference signal for high-resolution displacement measurement over a small interpolation range around the corresponding discrete absolute position xi. In the previous design of the optical head, the two beams were guided by optical fibers into a fiber coupler for the interference. This fiber optics design was simple and stable but could not identify the moving direction of small displacement within each interpolation range because only one interferential signal could be generated. The aim of this study is to develop a new design of the optical head, where two interference signals with a phase difference of π/2 are generated. For this purpose, free-space optics, instead of fiber optics, is adopted in the new optical head. Experiments are conducted to confirm the generation of the two phase-shifted interference signals. A Lissajous figure is plotted to verify the phase difference between the two signals.

Numerical Study of Eccentric Jet Impingement Cooling on a Heated Cylindrical Surface

Abstract This article presents a comprehensive numerical analysis of the effects of cooling a cylinder using an eccentric slot jet impingement cooling (SJIC). The study focuses on examining the thermal and fluid behavior when the slot jet is offcenter, during impingement cooling. Several turbulence models from the k–ε and k–ω families were compared by evaluating the local Nusselt number profiles at different locations around the cylinder, and these results were compared to experimental data. The findings indicate that the SST k–ω model outperforms the other turbulence models in estimating the Nusselt number in the stagnation region, while the standard k–ω model shows improved performance elsewhere on the cylinder. Furthermore, this study reveals a decrease in the maximum local Nusselt number and a shift in the direction of the nozzle displacement. The presence of swirling/recirculating fluid at the trailing end of the cylinder enhances heat transfer near the back end of the cylinder. The separation and the reattachment of the fluid stream differ depending on the Reynolds number, with low Reynolds numbers resulting in reattachment on the side of the slot jet and higher Reynolds numbers leading to reattachment in the opposite direction. Additionally, the length of the recirculation and swirling zones increases as the nozzle-to-cylinder spacing (H/S) increases. However, as the eccentricity (E/S) increases, the size of the swirl circulation zones decreases and completely vanishes for E/S = 4. This study provides valuable insights for optimal cooling design.

A retrospective cohort study of pulp prognosis in luxated permanent teeth: a competing risk analysis.

The present retrospective cohort study aimed to evaluate luxated permanent teeth for pulp prognosis and risk factors. Case records and radiographs of 224 patients, involving 427 luxated permanent teeth, referred for treatment at the Dental Trauma Center-School of Dentistry, Universidade Federal de Minas Gerais, (DTC-SD-UFMG) from 2014 to 2022, were assessed for pulp prognosis classified as vitality, necrosis and pulp canal obliteration (PCO). A competing risk survival analysis estimated the hazards of the three outcomes, and the effect of demographic, clinical and treatment variables was tested using a cause specific Cox regression model. Pulp vitality was found in163 teeth (38.2%), pulp necrosis in 120 teeth (28.1%) and 55 teeth (12.9%) developed PCO. Pulp vitality decreased in the presence of concomitant crown fractures (HR 0.38 95% CI [0.2-0.8] p = 0.006). The risk of pulp necrosis (HR 0.62 95% CI [0.4-0.96] p = 0.03) was lower in cases with open apices but increased with concomitant crown fractures (HR 4.0 95% CI [2.6-6.1] p = 0.001) and intrusions (HR 2.3 95% CI [1.2-4.1] p = 0.007). Lateral or extrusive luxations (HR 3.0 95% CI [1.3-6.9] p = 0.001) and open apices (HR 2.4 95% CI [1.2-4.7] p = 0.01) showed higher rates of PCO. Type of luxation, the diameter of the apical foramen, and the presence of concomitant crown fractures were main determinants of pulp prognosis after luxation injuries in permanent teeth. Pulp prognosis after tooth luxation is dependent on the presence and direction of tooth displacement together with infection control. Not applicable.

Evaluation of bone contact area and intercondylar distance changes in orthognathic surgery - a comparison between BSSO and HSSO technique depending on mandibular displacement extent

ObjectivesThe present study aims to assess the impact of bilateral and high oblique sagittal split osteotomy (BSSO/HSSO), as well as displacement distances and directions on the expected and achievable bone contact area (BCA) and changes in the intercondylar distance (ICD). The primary question addressed is whether mandibular splitting through BSSO results in a greater BCA and/or ICD when compared to splitting through HSSO.Materials and methodsTotally 80 mandibular displacements were performed on 20 fresh cadavers, for each subject, four splints were produces to facilitate mandibular advancement as well as setbacks of 4 and 8 mm. Pre- and postoperative CBCT scans were performed to plan the surgical procedures and to analyze the expected and achieved BCA and ICD.ResultsRegarding the maximum mandibular displacement, the expected BCA for HSSO/BSSO were 352.58 ± 96.55mm2 and 1164.00 ± 295.50mm2, respectively, after advancement and 349.11 ± 98.42mm2 and 1344.70 ± 287.23mm2, respectively, after setback. The achieved BCA for HSSO/BSSO were 229.37 ± 75.90mm2 and 391.38 ± 189.01mm2, respectively, after advancement and 278.03 ± 97.65mm2 and 413.52 ± 169.52 mm2, respectively after setback. The expected ICD for HSSO/BSSO were 4.51 ± 0.73 mm and 3.25 ± 1.17 mm after advancement and − 5.76 ± 1.07 mm and − 4.28 ± 1.58 mm after setback. The achieved ICD for HSSO/BSSO were 2.07 ± 2.9 mm and 1.7 ± 0.60 mm after advancement and − 2.57 ± 2.78 mm and − 1.28 ± 0.84 mm after setback. Significant differences between the BCA after HSSO and BSSO were at each displacement (p < 0.001), except for the achieved BCA after 8-mm setback and advancement (p ≥ 0.266). No significant differences were observed regarding ICD, except for the expected ICD after 8-mm setback and advancement (p ≤ 0.037).ConclusionsCompared to the virtual planning, the predictability regarding BCA and ICD was limited. ICD showed smaller clinical changes, BCA decreased significantly in the BSSO group.Clinical relevanceBCA and ICD might have been less important in choosing the suitable split technique. in orthognathic surgery.

Multiscale transport and 4D time-lapse imaging in precision-cut liver slices (PCLS).

Monitoring cellular processes across different levels of complexity, from the cellular to the tissue scale, is important for understanding tissue structure and function. However, it is challenging to monitor and estimate these structural and dynamic interactions within three-dimensional (3D) tissue models. The aim of this study was to design a method for imaging, tracking, and quantifying 3D changes in cell morphology (shape and size) within liver tissue, specifically a precision-cut liver slice (PCLS). A PCLS is a 3D model of the liver that allows the study of the structure and function of liver cells in their native microenvironment. Here, we present a method for imaging liver tissue during anisosmotic exposure in a multispectral four-dimensional manner. Three metrics of tissue morphology were measured to quantify the effects of osmotic stress on liver tissue. We estimated the changes in the volume of whole precision cut liver slices, quantified the changes in nuclei position, and calculated the changes in volumetric responses of tissue-embedded cells. During equilibration with cell-membrane-permeating and non-permeating solutes, the whole tissue experiences shrinkage and expansion. As nuclei showed a change in position and directional displacement under osmotic stress, we demonstrate that nuclei could be used as a probe to measure local osmotic and mechanical stress. Moreover, we demonstrate that cells change their volume within tissue slices as a result of osmotic perturbation and that this change in volume is dependent on the position of the cell within the tissue and the duration of the exposure. The results of this study have implications for a better understanding of multiscale transport, mechanobiology, and triggered biological responses within complex biological structures.

Identification of subtle residual sacroiliac joint flexion and extension malreductions in AO/OTA 61-C1.2 (APC3) pelvic injuries after provisional anterior ring reduction.

Hemipelvis reduction in the setting of AO/OTA 61-C1.2 (APC3) pelvic injuries can be challenging. A common strategy is to provisionally reduce or fix the anterior ring prior to definitive fixation of the posterior ring. In this scenario, it is difficult to assess whether residual sacroiliac joint (SIJ) widening is due to hemipelvis flexion/extension or lateral displacement. This simulation sought to identify a radiographic marker for posterior ilium flexion or extension malreduction in the setting of a reduced anterior ring. Symphyseal and both anterior and posterior SIJ ligaments were cut in 8 cadaveric pelvis. The symphysis was reduced and wired. One centimeter of posterior flexion or extension at the SIJ was created to mimic the clinical scenario of hemipelvis flexion or extension malreduction, and a lateral compressive force was applied. SIJ widening and the direction of anterior or posterior ileal displacement relative to the contralateral joint were assessed via inlet views. SIJ widening and the direction of cranial or caudal ileal displacement were assessed using outlet views. Comparisons between flexion and extension models used Fisher's exact test. On outlet views, all flexed hemipelvis demonstrated caudal ileal translation at the superior SIJ, in contrast to all extended hemipelvis demonstrated cranial translation (p < 0.0005); the scenarios were easily distinguishable. Conversely, inlet imaging was unable to identify the direction of malreduction. Flexion/extension scenarios resulted in similar amounts of SIJ widening. Residual flexion and extension hemipelvis malreductions in APC3 injuries after provisional anterior fixation can be differentiated by the direction of ileal displacement at the superior SIJ on the outlet view.

Surgical treatment of nonunion of the lateral humeral condyle in children using combined methods of bone grafting and the Ilizarov fixation

Introduction Elbow trauma is common accounting for 40-50 % of all musculoskeletal injuries in children. From them, lateral condyle fractures are the second most common fractures in the pediatric elbow with complications ranging from 3.3 to 54.8 %.The objective was to determine the effectiveness of nonunion of the lateral humeral condyle (LHC) treated with bone grafts harvested from the patient's fibular shaft and the Ilizarov apparatus.Material and methods We report surgical treatment of bone defect repaired with bone graft and the Ilizarov apparatus in 57 children with nonunion of the LHC. Maintained articulation between the non-united bone and the radial head, magnitude and direction of displacement, visible resorption of the epimetaphysis, bone deficiency, malaligned upper limb, late ulnar neuritis were the parameters used for outcome assessment. Depending on the type of surgical treatment the patients were divided into 3 groups: Group 1 (n = 13) included patients who underwent open osteosynthesis and bone fixation using 2-3 Kirschner wires; Group 2 (n = 30) consisted of patients who underwent surgery to repair the bone defect between the humerus metaphysis and an non-united fragment of the LHC fixed with wires and immobilized with a cast; Group 3 (n = 12) included patients who were treated with bone graft followed by fixation of the bone and the graft using Ilizarov wires and frame. Two patients underwent supracondylar osteotomy.Results The outcomes were evaluated based on criteria to include non-union consolidation, joint function, limb alignment and condition of the growth plate. Long-term results were explored in 49 (85.9 %) patients out of 57 over a period of 6 months to 10 years. The results were rates as good in 39 (79.6 %) patients, as fair in 9 (18.36 %) and poor in one (2.04 %) case.Discussion Various types of operations are reported for non-united fractures and non-unions of the cervical spine to include surgeries from open osteosynthesis to complicated reconstructions.Conclusion Surgeries aimed at repair of bone defects using fibular autograft facilitated consolidation of non-unions and engraftments.

Study on stress and deformation characteristics of existing-new two-stage cantilever retaining wall.

A two-stage cantilever retaining wall is composed of two single-stage cantilever retaining walls, which are stacked up and down. The structure not only has the advantages of a single-stage retaining wall, but also compensates for the shortcomings of the height limit of the single-stage retaining wall; therefore, it has been gradually applied in projects. Based on the actual project of Zhongwei-Lanzhou Passenger Dedicated Line into Lanzhou Hub, this paper studies the influence of the construction of new cantilever retaining wall and the filling of subgrade on the deformation and earth pressure of the new cantilever wall and the existing cantilever wall by means of field test and numerical simulation. The results show that with an increase in the filling height after the new cantilever wall (upper wall), the horizontal displacement of the top of the upper and lower walls increased nonlinearly. The displacement direction of the upper wall was the filling direction, and that of the lower wall was the deviation from the filling direction. The higher the filling height, the greater is the displacement. With an increase in the filling height, the earth pressure behind the upper wall increases gradually along the wall height and decreases slightly to the bottom of the wall, which is approximately a linear distribution. The earth pressure behind the existing cantilever wall first increases along the wall height and gradually decreases after reaching a certain depth, but the earth pressure of the lower wall does not increase significantly with an increase in the filling height behind the upper wall. The slope failure mode is the overall sliding failure of the retaining wall together with the fill soil. The sliding surface passed through the lower edge of the lower wall heel and was similar to an arc shape. The stability of the two-stage cantilever retaining wall was better than that of a single-stage retaining wall. Finally, a calculation method for the overall stability and earth pressure of the existing two-stage cantilever retaining wall was proposed.

Parametric Analysis on Creep Deformation of Deep-Sea PMMA Observation Window

Observation windows are core components of the submersible manned cabins. The strength and stiffness of the observation window during the loading and load-sustaining process are crucial to ensure the safety of the equipment and personnel inside the manned cabin. It is extremely important to accurately calculate the structural creep performance of the observation window under a long-period sustaining load in seawater. In the present study, finite element analyses based on a temperature-dependent time-hardening creep model are conducted to investigate the performance of the observation window. The mesh convergence is studied first and the parametric analysis is accordingly carried out, taking different combinations of temperatures from 2~30 °C, different loading rates of 2.3 MPa/min, 4.5 MPa/min, 6 MPa/min, and 8 MPa/min, and different friction coefficients of 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3 into account. The results show that the displacement in the y-axis direction of the center point of the lower surface of the viewport window increases with the increasing temperature and loading rate. On the contrary, the axial displacement of the observation window gradually decreases with the increase of the friction coefficient, and the axial displacement is the largest when the lowest friction coefficient is applied. This study aims to offer a more unified analysis and design methodology for the creep deformation of PMMA structures in underwater facilities.

A Low-Cost Inertial Measurement Unit Motion Capture System for Operation Posture Collection and Recognition.

In factories, human posture recognition facilitates human-machine collaboration, human risk management, and workflow improvement. Compared to optical sensors, inertial sensors have the advantages of portability and resistance to obstruction, making them suitable for factories. However, existing product-level inertial sensing solutions are generally expensive. This paper proposes a low-cost human motion capture system based on BMI 160, a type of six-axis inertial measurement unit (IMU). Based on WIFI communication, the collected data are processed to obtain the displacement of human joints' rotation angles around XYZ directions and the displacement in XYZ directions, then the human skeleton hierarchical relationship was combined to calculate the real-time human posture. Furthermore, the digital human model was been established on Unity3D to synchronously visualize and present human movements. We simulated assembly operations in a virtual reality environment for human posture data collection and posture recognition experiments. Six inertial sensors were placed on the chest, waist, knee joints, and ankle joints of both legs. There were 16,067 labeled samples obtained for posture recognition model training, and the accumulated displacement and the rotation angle of six joints in the three directions were used as input features. The bi-directional long short-term memory (BiLSTM) model was used to identify seven common operation postures: standing, slightly bending, deep bending, half-squatting, squatting, sitting, and supine, with an average accuracy of 98.24%. According to the experiment result, the proposed method could be used to develop a low-cost and effective solution to human posture recognition for factory operation.

Abnormal Oculomotor Corollary Discharge Signaling as a Trans-diagnostic Mechanism of Psychosis.

Corollary discharge (CD) signals are "copies" of motor signals sent to sensory areas to predict the corresponding input. They are a posited mechanism enabling one to distinguish actions generated by oneself vs external forces. Consequently, altered CD is a hypothesized mechanism for agency disturbances in psychosis. Previous studies have shown a decreased influence of CD signals on visual perception in individuals with schizophrenia-particularly in those with more severe positive symptoms. We therefore hypothesized that altered CD may be a trans-diagnostic mechanism of psychosis. We examined oculomotor CD (using the blanking task) in 49 participants with schizophrenia or schizoaffective disorder (SZ), 36 bipolar participants with psychosis (BPP), and 40 healthy controls (HC). Participants made a saccade to a visual target. Upon saccade initiation, the target disappeared and reappeared at a horizontally displaced position. Participants indicated the direction of displacement. With intact CD, participants can make accurate perceptual judgements. Otherwise, participants may use saccade landing site as a proxy of pre-saccadic target to inform perception. Thus, multi-level modeling was used to examine the influence of target displacement and saccade landing site on displacement judgements. SZ and BPP were equally less sensitive to target displacement than HC. Moreover, regardless of diagnosis, SZ and BPP with more severe positive symptoms were more likely to rely on saccade landing site. These results suggest that altered CD may be a trans-diagnostic mechanism of psychosis.

Micro‐mechanism of stress‐dilatancy anisotropy in granular materials: Affine and nonaffine deformation

AbstractThe stress‐induced dilatancy anisotropy is an important kinematic response in granular materials and is very complex due to the stochastic motion of particles. In this study, the local stress‐dilatancy relationship is investigated referring to the local contact force and relative displacement in a certain contact direction. The micromechanism of this anisotropy is investigated from the view of affine and nonaffine approaches based on DEM simulation. Numerical results indicate that the local nonaffine dilatancy/contraction tendency is opposite with that of local affine deformation in macroscopic compression and extension direction, which mainly stems from the counteraction effect between the normal components of affine and nonaffine displacements. The local stress‐dilatancy of affine and nonaffine components is linear and orientation‐dependent, which results in the nonlinear character of macroscopic stress‐dilatancy. By establishing an analytical relation of stress‐dilatancy, the local affine/nonaffine dilatancy is decomposed into the component of stress‐induced dilatancy synchronized with the local stress anisotropy; and the component of stress‐induced dilatancy asynchronized with the local stress anisotropy. The former is related to the unchanged isotropic microstructure, and the latter attributes to the anisotropic microstructure. Besides, the contribution of nonsliding contacts to nonaffine dilatancy is larger than that of sliding contacts even for the case of relatively higher sliding ratio, which indicates that the heterogeneous deformation attributes not only to the friction dissipation, but to the blocked energy at micro contacts in granular materials.

Predicting occupant head displacements in evasive maneuvers; tuning and comparison of a rotational based and a translational based neck muscle controller.

Objective: Real-life car crashes are often preceded by an evasive maneuver, which can alter the occupant posture and muscle state. To simulate the occupant response in such maneuvers, human body models (HBMs) with active muscles have been developed. The aim of this study was to implement an omni-directional rotational head-neck muscle controller in the SAFER HBM and compare the bio-fidelity of the HBM with a rotational controller to the HBM with a translational controller, in simulations of evasive maneuvers. Methods: The rotational controller was developed using an axis-angle representation of head rotations, with x, y, and z components in the axis. Muscle load sharing was based on rotational direction in the simulation and muscle activity recorded in three volunteer experiments in these directions. The gains of the rotational and translational controller were tuned to minimize differences between translational and rotational head displacements of the HBM and volunteers in braking and lane change maneuvers using multi-objective optimizations. Bio-fidelity of the model with tuned controllers was evaluated objectively using CORrelation and Analysis (CORA). Results: The results indicated comparable performance for both controllers after tuning, with somewhat higher bio-fidelity for rotational kinematics with the translational controller. After tuning, good or excellent bio-fidelity was indicated for both controllers in the loading direction (forward in braking, and lateral in lane change), with CORA scores of 0.86-0.99 and 0.93-0.98 for the rotational and translational controllers, respectively. For rotational displacements, and translational displacements in the other directions, bio-fidelity ranged from poor to excellent, with slightly higher average CORA scores for the HBM with the translational controller in both braking and lane changing. Time-averaged muscle activity was within one standard deviation of time-averaged muscle activity from volunteers. Conclusion: Overall, the results show that when tuned, both the translational and rotational controllers can be used to predict the occupant response to an evasive maneuver, allowing for the inclusion of evasive maneuvers prior to a crash in evaluation of vehicle safety. The rotational controller shows potential in controlling omni-directional head displacements, but the translational controller outperformed the rotational controller. Thus, for now, the recommendation is to use the translational controller with tuned gains.

Extrusion and meniscal mobility evaluation in case of ramp lesion injury: a biomechanical feasibility study by 7T magnetic resonance imaging and digital volume correlation.

Introduction: The existing body of literature on the biomechanical implications of ramp lesions is limited, leaving a significant gap in our understanding of how these lesions impact joint kinematics and loading in the medial compartment. This cadaveric biomechanical study aims to address this gap by employing an innovative Digital Volume Correlation (DVC) method, utilizing 7 Tesla Magnetic Resonance Imaging (MRI) images under various loading conditions. The primary objective is to conduct a comprehensive comparison of medial meniscal mobility between native knees and knees affected by grade 4 ramp lesions. By focusing on the intricate dynamics of meniscal mobility and extrusion, this work seeks to contribute valuable insights into the biomechanical consequences of medial meniscus ramp lesions. Materials and methods: An initial set of 7T MRI imaging sessions was conducted on two intact native knees, applying load values up to 1500N. Subsequently, a second series of images was captured on these identical knees, with the same loads applied, following the creation through arthroscopy of medial meniscus ramp lesions. The application of DVC enabled the precise determination of the three components of displacement and spatial variations in the medial menisci, both with and without ramp lesions. Results: The measured directional displacements between native knees and injured knees indicate that, following the application of axial compression load, menisci exhibit increased extrusion and posterior mobility as observed through DVC. Discussion: Injuries associated with Subtype 4 medial meniscus ramp lesions appear to elevate meniscal extrusion and posterior mobility during axial compression in the anterior cruciate ligament of intact knees. Following these preliminary results, we plan to expand our experimental approach to encompass individuals undergoing weight-bearing MRI. This expansion aims to identify meniscocapsular and/or meniscotibial insufficiency or rupture in patients, enabling us to proactively reduce the risk of osteoarthritic progression.

Assessing the Impact of a 1.5 T Transverse Magnetic Field in Radiotherapy for Esophageal Cancer Patients.

Purpose: Magnetic resonance (MR)-guided radiotherapy enables visualization of static anatomy, capturing tumor motion, and extracting quantitative image features for treatment verification and outcome monitoring. However, magnetic fields in online MR imaging (MRI) require efforts to ensure accurate dose measurements. This study aimed to assess the dosimetric impact of a 1.5 T magnetic field in esophageal cancer radiotherapy using MR-linac, exploring treatment adaptation potential and personalized medicine benefits. Methods: A prospective cohort study enrolled 100 esophageal squamous cell carcinoma patients undergoing 4DCT and 3DCT scans before radiotherapy. The heart was contoured on 3DCT, 4DCT end expiration (EE), and 4DCT end inhalation (EI) images by the same radiation oncologist. Reference RT plans were designed on 3DCT, with adjustments for different phases generating 5 plan types per patient. Variations in dose-volume parameters for organs at risk and the target area among different plans were compared using Monaco 5.40.04. Results: Slight dose distortions at air-tissue interfaces were observed in the magnetic field's presence. Dose at air-tissue interfaces (chest wall and heart wall) was slightly higher in some patients (3.0% tissue increased by 4.3 Gy on average) compared to nonmagnetic conditions. Average clinical target volume coverage V100 dropped from 99% to 95% compared to reference plans (planEI and planEE). Dose-volume histogram variation between the original plan and reference plans was within 2.3%. Superior-inferior (SI) direction displacement was significantly larger than lateral and anterior-posterior directions (P < .05). Conclusion: Significant SI direction shift in lower esophageal cancerous regions during RT indicates the magnetic field's dosimetric impact, including the electron return effect at tissue-air boundaries. Changes in OAR dose could serve as valuable indicators of organ impairment and target dose alterations, especially for cardiac tissue when using the 1.5 T linac method. Reoptimizing the plan with the magnetic field enhances the feasibility of achieving a clinically acceptable treatment plan for esophageal cancer patients.

UNDERSTANDING THE BIOMECHANICAL RESPONSE OF PROGRESSIVE THREAD DENTAL IMPLANTS USING MULTI-SCALE FINITE ELEMENT ANALYSIS

Implant osseointegration is an important factor dictating its long-term efficacy in situ. Along with various biological factors, it is greatly influenced by the mechanical stimulus at the peri-implant bone. The present study aims to understand the biomechanical response of progressive thread dental implants using multi-scale-based finite element analysis employing macro and micro models of bone. &amp;mu;-CT images of a cadaveric human mandible of its premolar region were obtained, along with CT scan of the same region to generate computational models. Total of six dental implants were designed having regular and progressive thread depths. Three different stages of healing of the bone-implant assembly were simulated parametrically. The biomechanical environment at the peri-implant bone was analyzed considering the 'Mechanostat' hypothesis. The obtained results revealed that bone strain is significantly higher during the initial healing phase when the bone is weakest. During this phase, implant stress and its displacement in both buccolingual and coronoapical directions are also noticeably higher. Also, displacements of progressive thread implants were lower in all the healing phases as compared to the implants with constant thread depth. The observations of this &amp;mu; FEA study highlights the clinical applicability of a progressive thread dental implant as it generates larger functional surface area, thus engages higher trabeculae and therefore is suitable for weaker bone conditions. Furthermore, by comparing the stress values at bone and implant between the two bone models, the CT-based model having inhomogeneous material was deemed suitable as an alternative to computationally expensive &amp;mu; FEA.

Comparison of the Effects of Cognitive Dual-Task and Single-Task Balance Exercises on Static Balance among People with Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial.

The anterior cruciate ligament (ACL) reconstruction surgery improves mechanical stability; however, functional stability remains impaired. Balance exercises can help improve functional stability. The effect of cognitive dual-task balance exercises has not been studied in people with ACL reconstruction surgery; therefore, this study aimed to compare the effect of cognitive dual-task and single-task balance exercises on the static balance indices in these individuals. This study was a randomized clinical trial. After a period of conventional physiotherapy and applying inclusion criteria, 28 patients with ACL reconstruction surgery were randomly divided into two groups of cognitive dual-task and single-task balance exercises. Each group received the relevant exercises for four weeks, three times a week, with each session lasting 20 min. Center of pressure variables, including mean displacement in anterior-posterior and medial-lateral directions, total path length, mean velocity of displacement, root mean square of displacement and velocity, and the elliptical area, were measured using the FDM pressure platform before and after the interventions as the primary outcomes. Knee Injury and Osteoarthritis Outcome Score (KOOS) scale was completed by the participants before and after the interventions. The measured static balance variables and KOOS subscales had significant differences before and after intervention in both groups (P<0.05); however, no statistically significant difference was observed in these variables between the two groups. There was no significant correlation between KOOS subscales and measured static balance variables. Both cognitive dual-task and single-task balance exercises improved the indicators related to static balance and the level of functional disability of the knee. However, cognitive dual-task balance exercises had no superiority over single-task balance exercises in ACL-reconstructed individuals.

Along-Track Displacement of Mw 7.8 and 7.6 Kahramanmaraş Earthquakes from Sentinel-1 Offset Tracking and Burst Overlap Interferometry

On 6th February, a pair of significant earthquakes with magnitudes of 7.8 and 7.6 struck Kahramanmaraş, Turkey. The Earthquake InSAR Data Provider (EIDP) promptly produced interferograms and offset tracking results within 3 hours of acquiring Sentinel-1 satellite data. However, it was challenging to unwrap the interferograms correctly due to high displacement gradient near the rupture. Hence, early displacement fields were derived from Pixel Offset Tracking (POT) method both in range and azimuth direction with low resolution depending on pixel sizes of Sentinel-1. We used the Burst Overlap Interferometry (BOI) method to extract the accurate along-track displacement and unwrapped the BOI interferogram using Azimuth Offset Tracking (AOT) data as a guide. Combining the unwrapped BOI interferogram and the AOT data, we derive a high-quality along-track displacement field that illuminates the entire earthquake rupture over 350 km and exhibits ±4 m displacement in the along-track direction.