Eliminating 2D spinal assessments and embracing 3D and 4D: clinical application of surface topography

Author(s):  
P Knott ◽  
XC Liu

The Adams Forward Bend Test recognizes the rotational aspect of the curve with the spine in flexion, and the AP X-ray measures the coronal plane deviation by using the Cobb Angle. However, modern techniques including CT-scan, biplanar radiograph, ultrasound, and surface topography allow the clinician to better evaluate and visualize the true 3-D nature of the spine. Surface Topography imaging uses the surface of the trunk to estimate the spine position using a mathematical algorithm that has been found to be accurate when compared to the radiologic Cobb Angle. The sagittal balance of the spine measured by surface topography is compared in three different situations, namely, “standing up straight,” “standing relaxed,” and “walking,” which will help to best assess posture and risk of proximal junctional kyphosis before and after the treatment. Coronal imbalance (lateral deviation) and a range of maximal vertebral surface rotation (amplitude in either direction) are considered as the parameters with an excellent to good reproducibility. COP displacement or symmetry from the midline is used to measure the stability of the trunk. Therefore, those selected spine shape parameters and COP deviation would be considered as the best descriptors in the assessment of postural sway and outcome of PSSE in children with AIS.

Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.


2020 ◽  
Vol 90 (5-6) ◽  
pp. 439-447 ◽  
Author(s):  
Andrew Hadinata Lie ◽  
Maria V Chandra-Hioe ◽  
Jayashree Arcot

Abstract. The stability of B12 vitamers is affected by interaction with other water-soluble vitamins, UV light, heat, and pH. This study compared the degradation losses in cyanocobalamin, hydroxocobalamin and methylcobalamin due to the physicochemical exposure before and after the addition of sorbitol. The degradation losses of cyanocobalamin in the presence of increasing concentrations of thiamin and niacin ranged between 6%-13% and added sorbitol significantly prevented the loss of cyanocobalamin (p<0.05). Hydroxocobalamin and methylcobalamin exhibited degradation losses ranging from 24%–26% and 48%–76%, respectively; added sorbitol significantly minimised the loss to 10% and 20%, respectively (p < 0.05). Methylcobalamin was the most susceptible to degradation when co-existing with ascorbic acid, followed by hydroxocobalamin and cyanocobalamin. The presence of ascorbic acid caused the greatest degradation loss in methylcobalamin (70%-76%), which was minimised to 16% with added sorbitol (p < 0.05). Heat exposure (100 °C, 60 minutes) caused a greater loss of cyanocobalamin (38%) than UV exposure (4%). However, degradation losses in hydroxocobalamin and methylcobalamin due to UV and heat exposures were comparable (>30%). At pH 3, methylcobalamin was the most unstable showing 79% degradation loss, which was down to 12% after sorbitol was added (p < 0.05). The losses of cyanocobalamin at pH 3 and pH 9 (~15%) were prevented by adding sorbitol. Addition of sorbitol to hydroxocobalamin at pH 3 and pH 9 reduced the loss by only 6%. The results showed that cyanocobalamin was the most stable, followed by hydroxocobalamin and methylcobalamin. Added sorbitol was sufficient to significantly enhance the stability of cobalamins against degradative agents and conditions.


Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 4997
Author(s):  
Victor C. Le ◽  
Monica L. H. Jones ◽  
Kathleen H. Sienko

Postural sway has been demonstrated to increase following exposure to different types of motion. However, limited prior studies have investigated the relationship between exposure to normative on-road driving conditions and standing balance following the exposure. The purpose of this on-road study was to quantify the effect of vehicle motion and task performance on passengers’ post-drive standing balance performance. In this study, trunk-based kinematic data were captured while participants performed a series of balance exercises before and after an on-road driving session in real-time traffic. Postural sway for all balance exercises increased following the driving session. Performing a series of ecologically relevant visual-based tasks led to increases in most post-drive balance metrics such as sway position and velocity. However, the post-drive changes following the driving session with a task were not significantly different compared to changes observed following the driving session without a task. The post-drive standing balance performance changes observed in this study may increase vulnerable users’ risk of falling. Wearable sensors offer an opportunity to monitor postural sway following in-vehicle exposures.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3567
Author(s):  
Faiza Faiza ◽  
Abraiz Khattak ◽  
Safi Ullah Butt ◽  
Kashif Imran ◽  
Abasin Ulasyar ◽  
...  

Silicone rubber is a promising insulating material that has been performing well for different insulating and dielectric applications. However, in outdoor applications, environmental stresses cause structural and surface degradations that diminish its insulating properties. This effect of degradation can be reduced with the addition of a suitable filler to the polymer chains. For the investigation of structural changes and hydrophobicity four different systems were fabricated, including neat silicone rubber, a micro composite (with 15% micro-silica filler), and nanocomposites (with 2.5% and 5% nanosilica filler) by subjecting them to various hydrothermal conditions. In general, remarkable results were obtained by the addition of fillers. However, nanocomposites showed the best resistance against the applied stresses. In comparison to neat silicone rubber, the stability of the structure and hydrophobic behavior was better for micro-silica, which was further enhanced in the case of nanocomposites. The inclusion of 5% nanosilica showed the best results before and after applying aging conditions.


2014 ◽  
Vol 501-504 ◽  
pp. 2001-2006
Author(s):  
Ya Liu ◽  
Li Zheng ◽  
Cheng Tao Huang ◽  
Zhao Biao Huang ◽  
Lin Liu

After impoundment of the Three Gorges Reservoir, Jingjiang reach, in the middle of the Yangtze River, has gradually shown a series of atypical fluvial features, adversely affecting the maintenance of waterways. Citing the Laijiapu Waterway, a meandering segment in the lower Jingjiang for example, this paper compared the fluvial features of the channel before and after the impoundment, summed up its navigation-obstructing features, and proposed guarding the point bar on the convex bank and channel bar in the widening section as a key to maintaining the stability of the navigation channels.


2013 ◽  
Vol 1 (6) ◽  
pp. 452-457 ◽  
Author(s):  
Paul Brewer ◽  
Fiona Berryman ◽  
De Baker ◽  
Paul Pynsent ◽  
Adrian Gardner

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Andre Shihomatsu ◽  
Sergio Tonini Button ◽  
Iris Bento da Silva

Hot stamping of high strength steels has been continuously developed in the automotive industry to improve mechanical properties and surface quality of stamped components. One of the main challenges faced by researchers and technicians is to improve stamping dies lifetime by reducing the wear caused by high pressures and temperatures present during the process. This paper analyzes the laser texturing of hot stamping dies and discusses how different surfaces textures influence the lubrication and wear mechanisms. To this purpose, experimental tests and numerical simulation were carried out to define the die region to be texturized and to characterize the textured surface topography before and after hot stamping tests with a 3D surface profilometer and scanning electron microscopy. Results showed that laser texturing influences the lubrication at the interface die-hot sheet and improves die lifetime. In this work, the best texture presented dimples with the highest diameter, depth, and spacing, with the surface topography and dimples morphology practically preserved after the hot stamping tests.


Neurosurgery ◽  
2021 ◽  
Author(s):  
Alan H Daniels ◽  
Wesley M Durand ◽  
Renaud Lafage ◽  
Andrew S Zhang ◽  
David K Hamilton ◽  
...  

Abstract BACKGROUND Lateral (ie, coronal) vertebral listhesis may contribute to disability in adult scoliosis patients. OBJECTIVE To assess for a correlation between lateral listhesis and disability among patients with adult scoliosis. METHODS This was a retrospective multi-center analysis of prospectively collected data. Patients eligible for a minimum of 2-yr follow-up and with coronal plane deformity (defined as maximum Cobb angle ≥20º) were included (n = 724). Outcome measures were Oswestry Disability Index (ODI) and leg pain numeric scale rating. Lateral thoracolumbar listhesis was measured as the maximum vertebral listhesis as a percent of the superior endplate across T1-L5 levels. Linear and logistic regression was utilized, as appropriate. Multivariable analyses adjusted for demographics, comorbidities, surgical invasiveness, maximum Cobb angle, and T1-PA. Minimally clinically important difference (MCID) in ODI was defined as 12.8. RESULTS In total, 724 adult patients were assessed. The mean baseline maximum lateral thoracolumbar listhesis was 18.3% (standard deviation 9.7%). The optimal statistical grouping for lateral listhesis was empirically determined to be none/mild (&lt;6.7%), moderate (6.7-15.4%), and severe (≥15.4%). In multivariable analysis, listhesis of moderate and severe vs none/mild was associated with worse baseline ODI (none/mild = 33.7; moderate = 41.6; severe = 43.9; P &lt; .001 for both comparisons) and leg pain NSR (none/mild = 2.9, moderate = 4.0, severe = 5.1, P &lt; .05). Resolution of severe lateral listhesis to none/mild was independently associated with increased likelihood of reaching MCID in ODI at 2 yr postoperatively (odds ratio 2.1 95% confidence interval 1.2–3.7, P = .0097). CONCLUSION Lateral thoracolumbar listhesis is associated with worse baseline disability among adult scoliosis patients. Resolution of severe lateral listhesis following deformity correction was independently associated with increased likelihood of reaching MCID in ODI at 2-yr follow-up.


2017 ◽  
Vol 11 (1) ◽  
pp. 301-311
Author(s):  
Felipe J. Fernández-González ◽  
Jorge Cabero-López ◽  
Aritza Brizuela ◽  
Ivan Suazo ◽  
Esteban Pérez-Pevida ◽  
...  

Background:For patients whose centric relation (CR) has not been considered at the start and during treatment, the task of achieving an occlusal scheme that works together with the temporomandibular joint, the muscles, and the structures of the stomatognathic apparatus becomes a major concern.Objective:This study aims to describe a reproducible, predictable and to date unreported procedure of selective grinding guided by an occlusal splint and to analyze condylar position (CP) based on the skeletal pattern.Methods:A total of 72 symptomatic patients (38 females and 34 males) were classified into three groups: hyperdivergent, intermediate and hypodivergent. CP was quantified by mounted casts on a measures condyle displacement (MCD) device. Helkimo index was also performed in order to assess the severity of the temporomandibular joint (TMJ) disorders attending to clinical dysfunction, occlusal state and anamnestic dysfunction. Once the stability had been obtained, the splint was progressively reduced until the maximum intercuspation (MIC) was achieved.Results:The vertical displacement was found to be significantly different between the hyperdivergent and other two groups (p<0.01). Comparisons of MCD analysis before and after the selective grinding procedure identified a statistically significant difference in the horizontal and vertical CP (p<0.01) between the different groups whereas the Helkimo Index showed a clear improvement of TMJ disorders.Conclusion:All facial types, specially the hyperdivergent face type, showed a reduction in condylar displacement (CD) and less craniomandibular symptoms using this procedure, making it an excellent technique for clinicians.


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