Gotowe bibliografie tematyczne / Endplate

Spis treści

Artykuły w czasopismach
Rozprawy doktorskie
Książki
Części książek
Streszczenia konferencji
Raporty organizacyjne

Gotowa bibliografia na temat „Endplate”

Autor: Grafiati

Data publikacji: 4 czerwca 2021

Data aktualizacji: 19 lutego 2022

Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych

Wybierz rodzaj źródła:

Zobacz listy aktualnych artykułów, książek, rozpraw, streszczeń i innych źródeł naukowych na temat „Endplate”.

Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.

Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.

Artykuły w czasopismach na temat "Endplate"

Duran, Semra, Mehtap Cavusoglu, Hatice Gul Hatipoglu, Deniz Sozmen Cılız i Bulent Sakman. "Association between Measures of Vertebral Endplate Morphology and Lumbar Intervertebral Disc Degeneration". Canadian Association of Radiologists Journal 68, nr 2 (maj 2017): 210–16. http://dx.doi.org/10.1016/j.carj.2016.11.002.

Pełny tekst źródła

Streszczenie:

Purpose The aim of this study was to evaluate the association between vertebral endplate morphology and the degree of lumbar intervertebral disc degeneration via magnetic resonance imaging (MRI). Methods In total, 150 patients who met the inclusion criteria and were 20–60 years of age were retrospectively evaluated. Patients were evaluated for the presence of intervertebral disc degeneration or herniation, and the degree of degeneration was assessed at all lumbar levels. Vertebral endplate morphology was evaluated based on the endplate sagittal diameter, endplate sagittal concave angle (ECA), and endplate sagittal concave depth (ECD) on sagittal MRI. The association between intervertebral disc degeneration or herniation and endplate morphological measurements was analysed. Results In MRI, superior endplates ( ie, inferior endplates of the superior vertebra) were concave and inferior endplates ( ie, superior endplates of the inferior vertebra) were flat at all disc levels. A decrease in ECD and an increase in ECA were detected at all lumbar levels as disc degeneration increased ( P < .05). At the L4-L5 and L5-S1 levels, a decrease in ECD and an increase in ECA were detected in the group with herniated lumbar discs ( P < .05). There was no association between lumbar disc degeneration or herniation and endplate sagittal diameter at lumbar intervertebral levels ( P > .05). At all levels, ECD of women was significantly lesser than that of men and ECA of women was significantly greater than that of men ( P < .05). Conclusions There is an association between vertebral endplate morphology and lumbar intervertebral disc degeneration. Vertebral endplates at the degenerated disc level become flat; the severity of this flattening is correlated with the degree of disc degeneration.

Style APA, Harvard, Vancouver, ISO itp.

Nagaraja, Srinidhi, Hassan K. Awada, Maureen L. Dreher, John T. Bouck i Shikha Gupta. "Effects of vertebroplasty on endplate subsidence in elderly female spines". Journal of Neurosurgery: Spine 22, nr 3 (marzec 2015): 273–82. http://dx.doi.org/10.3171/2014.10.spine14195.

Pełny tekst źródła

Streszczenie:

OBJECT The aim in this study was to quantify the effects of vertebroplasty on endplate subsidence in treated and adjacent vertebrae and their relationship to endplate thickness and underlying trabecular bone in elderly female spines. METHODS Vertebral compression fractures were created in female cadaveric (age range 51–88 years) thoracolumbar spine segments. Specimens were placed into either the control or vertebroplasty group (n = 9/group) such that bone mineral density, trabecular microarchitecture, and age were statistically similar between groups. For the vertebroplasty group, polymethylmethacrylate bone cement was injected into the fractured vertebral body under fluoroscopy. Cyclic compression (685–1370 N sinusoid) was performed on all spine segments for 115,000 cycles. Micro-CT scans were obtained before and after cyclic loading to quantify endplate subsidence. Maximum subsidence was compared between groups in the caudal endplate of the superior adjacent vertebra (SVcau); cranial (TVcra) and caudal (TVcau) endplates of the treated vertebra; and the cranial endplate of the inferior adjacent vertebra (IVcra). In addition, micro-CT images were used to quantify average endplate thickness and trabecular bone volume fraction. These parameters were then correlated with maximum endplate subsidence for each endplate. RESULTS The maximum subsidence in SVcau endplate for the vertebroplasty group (0.34 ± 0.58 mm) was significantly (p < 0.05) greater than for the control group (−0.13 ± 0.27 mm). Maximum subsidence in the TVcra, TVcau, and IVcra endplates were greater in the vertebroplasty group, but these differences were not significant (p > 0.16). Increased subsidence in the vertebroplasty group manifested locally in the anterior region of the SVcau endplate and in the posterior region of the TVcra and TVcau endplates (p < 0.10). Increased subsidence was observed in thinner endplates with lower trabecular bone volume fraction for both vertebroplasty and control groups (R2 correlation up to 62%). In the SVcau endplate specifically, these 2 covariates aided in understanding subsidence differences between vertebroplasty and control groups. CONCLUSIONS Bone cement injected during vertebroplasty alters local biomechanics in elderly female spines, resulting in increased endplate disruption in treated and superior adjacent vertebrae. More specifically, bone cement increases subsidence in the posterior regions of the treated endplates and the anterior region of the superior caudal endplate. This increased subsidence may be the initial mechanism leading to subsequent compression fractures after vertebroplasty, particularly in vertebrae superior to the treated level.

Style APA, Harvard, Vancouver, ISO itp.

Chen, Xiaofeng, Weijun Guo, Hao Li, Xi Li, Zhuangxun Han, Xueyuan Chu, Zehui Lao, Junxian Xie i Dongling Cai. "Evaluation of Cartilaginous Endplate Degeneration Based on Magnetic Resonance Imaging". Journal of Healthcare Engineering 2021 (23.03.2021): 1–12. http://dx.doi.org/10.1155/2021/5534227.

Pełny tekst źródła

Streszczenie:

In order to carry out the evaluation of cartilaginous endplate degeneration based on magnetic resonance imaging (MRI), this paper retrospectively analyzed the MRI data from 120 cases of patients who were diagnosed as lumbar intervertebral disc degeneration and underwent MRI examinations in the designated hospital of this study from June 2018 to June 2020. All cases underwent conventional sagittal and transverse T1WI and T2WI scans, and some cases were added with sagittal fat-suppression T2WI scans; then, the number of degenerative cartilaginous endplates and its ratio to degenerative lumbar intervertebral discs were counted and calculated, and the T1WI and T2WI signal characteristics of each degenerative cartilage endplate and its correlation with cartilaginous endplate degeneration were summarized, compared, and analyzed to evaluate the cartilaginous endplate degeneration by those magnetic resonance information. The study results show that there were 33 cases of cartilaginous endplate degeneration, accounting for 27.50% of all those 120 patients with lumbar intervertebral disc degeneration (54 degenerative endplates in total), including 9 cases with low T1WI and high T2WI signals, 5 cases with high T1WI and low T2WI signals, 12 cases with high and low mixed T1WI and high or mixed T2WI signals, and 4 cases with both low T1WI and T2WI signals. Therefore, MRI scanning can clearly present the abnormal signals of lumbar intervertebral disc and cartilaginous endplate degeneration, accurately identity their lesion locations, and type their degenerative characteristics, which may be best inspection method for the evaluation of cartilaginous endplate degeneration in the early diagnosis of intervertebral disc degeneration. The study results of this paper provide a reference for further researches on the evaluation of cartilaginous endplate degeneration based on magnetic resonance imaging.

Style APA, Harvard, Vancouver, ISO itp.

Liu, Sijing, Qiong Wang, Ziyi Li, Lei Ma, Ting Li, Yukun Li, Na Wang, Chang Liu, Peng Xue i Chuan Wang. "TRPV1 Channel Activated by the PGE2/EP4 Pathway Mediates Spinal Hypersensitivity in a Mouse Model of Vertebral Endplate Degeneration". Oxidative Medicine and Cellular Longevity 2021 (21.08.2021): 1–16. http://dx.doi.org/10.1155/2021/9965737.

Pełny tekst źródła

Streszczenie:

Low back pain (LBP) is the primary cause of disability globally. There is a close relationship between Modic changes or endplate defects and LBP. Endplates undergo ossification and become highly porous during intervertebral disc (IVD) degeneration. In our study, we used a mouse model of vertebral endplate degeneration by lumbar spine instability (LSI) surgery. Safranin O and fast green staining and μCT scan showed that LSI surgery led to endplate ossification and porosity, but the endplates in the sham group were cartilaginous and homogenous. Immunofluorescent staining demonstrated the innervation of calcitonin gene-related peptide- (CGRP-) positive nerve fibers in the porous endplate of LSI mice. Behavior test experiments showed an increased spinal hypersensitivity in LSI mice. Moreover, we found an increased cyclooxygenase 2 (COX2) expression and an elevated prostaglandin E2 (PGE2) concentration in the porous endplate of LSI mice. Immunofluorescent staining showed the colocalization of E-prostanoid 4 (EP4)/transient receptor potential vanilloid 1 (TRPV1) and CGRP in the nerve endings in the endplate and in the dorsal root ganglion (DRG) neurons, and western blotting analysis demonstrated that EP4 and TRPV1 expression significantly increased in the LSI group. Our patch clamp study further showed that LSI surgery significantly enhanced the current density of the TRPV1 channel in small-size DRG neurons. A selective EP4 receptor antagonist, L161982, reduced the spinal hypersensitivity of LSI mice by blocking the PGE2/EP4 pathway. In addition, TRPV1 current and neuronal excitability in DRG neurons were also significantly decreased by L161982 treatment. In summary, the PGE2/EP4 pathway in the porous endplate could activate the TRPV1 channel in DRG neurons to cause spinal hypersensitivity in LSI mice. L161982, a selective EP4 receptor antagonist, could turn down the TRPV1 current and decrease the neuronal excitability of DRG neurons to reduce spinal pain.

Style APA, Harvard, Vancouver, ISO itp.

Yao, Qi, Peng Yin, Kamran Khan, Tsung-Yuan Tsai, Jing-Sheng Li, Yong Hai, Peifu Tang i Guoan Li. "Differences of the Morphology of Subaxial Cervical Spine Endplates between Chinese and White Men and Women". BioMed Research International 2018 (2018): 1–8. http://dx.doi.org/10.1155/2018/2854175.

Pełny tekst źródła

Streszczenie:

Objective. The aim of this comparative anatomical study was to specifically investigate endplate morphology differences between Chinese and White men and women. Materials and Methods. Three-dimensional cervical endplate models were constructed using computed tomography imaging of 41 healthy Chinese and 24 White subjects. The morphologic measurements of cervical endplate included linear parameters (EPWu: upper endplate width; EPDu: upper endplate depth; EPWl: lower endplate width; and EPDl: lower endplate depth) and area parameters with a digital measuring system. Results. All linear parameters showed a constant increase from C3 to C7 except for EPDl in both the Chinese and the White subjects. An increase trend was observed on area parameters in both Chinese and White subjects. The ratio of EPWl/EPDl was smaller in Chinese females than in White females at C3, C4, and C6 levels (P<0.05). The ratio of EPWl/EPDl was significantly different between the Chinese and White men at C4-5 levels (P<0.05). Conclusions. Our data indicates that the morphology of subaxial cervical spine endplates between Chinese and White men and women is different in most of the linear and area parameters. This information could provide guidelines for the design of CDA implants and the improvement of surgical techniques.

Style APA, Harvard, Vancouver, ISO itp.

Herrero, Carlos Fernando P. S., Sergio Britto Garcia, Luis Vicente Garcia i Helton Luiz Aparecido Defino. "Endplates Changes Related to Age and Vertebral Segment". BioMed Research International 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/545017.

Pełny tekst źródła

Streszczenie:

Endplate separations are defined as the presence of a space between the hyaline cartilage and the cortical bone of the adjacent vertebral body. This study evaluates endplate separations from the vertebral body and intervertebral discs and verifies if endplate separation is related to age and the spinal level. Groups were formed based on age (20–40 and 41–85 years old) and the vertebral segment (T7-T8 and L4-L5 segments). Histological analysis included assessment of the length of the vertebral endplates, the number and dimensions of the separations, and orientation of the collagen fibers, in the mid-sagittal slice. Two indexes were created: the separation index (number of separations/vertebral length) and separation extension index (sum of all separations/vertebral length). The results of the study demonstrated a direct relationship between the density of separations in the endplate and two variables: age and spinal level.

Style APA, Harvard, Vancouver, ISO itp.

Chen, Shiming, Junming Jiang i Liangjiu Jia. "Numerical study on the performance of beam-to-concrete-filled steel tube column joint with adapter-bracket". Advances in Structural Engineering 21, nr 10 (27.12.2017): 1542–52. http://dx.doi.org/10.1177/1369433217746345.

Pełny tekst źródła

Streszczenie:

An innovative beam-to-column composite joint with adapter-bracket was proposed and its behavior was investigated through finite element analysis. The special adapter-bracket is to facilitate the assembly of the steel box beam and the concrete-filled steel tube column through high-strength blind bolts. In the adapter-bracket, two endplates are welded to the beam and bolted to the column, respectively. First, two finite element models of the bolted extended endplate joint were developed in ABAQUS and validated by available experimental results. Then, based on modified models, parametric analyses were conducted to evaluate the novel joint performance, in terms of the initial stiffness, rotation capacity, moment capacity, failure mode, and joint classification. The variables included flange thickness, endplate thickness, and bolt size. Results demonstrated that the joint behavior was significantly affected by the flange thickness, the endplate-A thickness, and bolt size while slightly influenced by the endplate-B thickness. Additionally, these joints had favorable rotation and moment capacity.

Style APA, Harvard, Vancouver, ISO itp.

Jensen, T. S., J. S. Sorensen i P. Kjaer. "Intra- and interobserver reproducibility of vertebral endplate signal (Modic) changes in the lumbar spine: the nordic modic consensus group classification". Acta Radiologica 48, nr 7 (wrzesień 2007): 748–54. http://dx.doi.org/10.1080/02841850701422112.

Pełny tekst źródła

Streszczenie:

Background: The lumbar vertebral endplate is considered a potential cause of specific low back pain. However, in relation to future research, there is need for a reliable and detailed magnetic resonance imaging (MRI) protocol to be used in the evaluation of vertebral endplate signal changes. Purpose: To assess the intra- and interobserver reliability of the “Nordic Modic classification” protocol. Material and Methods: MRI scans of 50 individuals representative of the general Danish population aged 40 were evaluated by two observers. Criteria for grading the changes were developed by the Nordic Modic Consensus Group. After consensus was established, all 50 MRI examinations were evaluated independently by each observer. Intraobserver reliability was assessed by re-evaluation of the 50 examinations by one of the observers. Kappa statistics were used to calculate agreement. Results: Intra- and interobserver agreement of the evaluation of variables describing vertebral signal changes, i.e. Modic type, location, volume, maximum height, and endplate area, were all found to have substantial to almost perfect agreement. The evaluation of osteophytes was found to be reliable, whereas the evaluation of localized endplate defects and irregular endplates had only moderate agreement. The evaluation of development over time was found to have substantial intraobserver agreement but only moderate interobserver agreement. As expected, intraobserver agreement was generally better than interobserver agreement. Conclusion: In this study, we found convincing reproducibility of a detailed evaluation protocol of vertebral endplate signal changes, the “Nordic Modic Classification.” The authors recommend that the evaluation protocol should be used in future studies investigating vertebral endplate signal changes.

Style APA, Harvard, Vancouver, ISO itp.

Desaulniers, Patrice, Pierre-André Lavoie i Phillip F. Gardiner. "Habitual exercise enhances neuromuscular transmission efficacy of rat soleus muscle in situ". Journal of Applied Physiology 90, nr 3 (1.03.2001): 1041–48. http://dx.doi.org/10.1152/jappl.2001.90.3.1041.

Pełny tekst źródła

Streszczenie:

Rat motor nerve terminals and the endplates they interact with exhibit changes to varying patterns of use, as when exposed to increased activation in the form of endurance exercise training. The extent to which these changes affect neuromuscular transmission efficacy is uncertain. In this study, the effects of habitual exercise on the electrophysiological properties of neuromuscular transmission in rat soleus muscle were investigated using a novel in situ approach. Consistent with previous reports, miniature endplate potential frequency was enhanced by habitual exercise. Other passive properties, such as resting membrane potential, miniature endplate potential amplitude, and “giant” miniature endplate potential characteristics were unaltered by the training program. Full-size endplate potentials were obtained by blocking soleus muscle action potentials with μ-conotoxin GIIIb. Quantal content values were 91.5 and 119.9 for control and active groups, respectively ( P < 0.01). We also measured the rate and extent of endplate potential amplitude rundown during 3-s trains of continuous stimulation at 25, 50, and 75 Hz; at 50 and 75 Hz, we found both the rate and extent of rundown to be significantly attenuated (10–20%) in a specific population of cells from active rats ( P < 0.05). The results establish the degree of activity-dependent plasticity as it pertains to neuromuscular transmission in a mammalian slow-twitch muscle.

Style APA, Harvard, Vancouver, ISO itp.

Fung, K., N. D. Hogikyan, S. B. Heavner, D. Ekbom i E. L. Feldman. "Development and characterisation of an experimental recurrent laryngeal nerve injury model for the study of viral gene therapy". Journal of Laryngology & Otology 122, nr 5 (25.06.2007): 500–505. http://dx.doi.org/10.1017/s0022215107009097.

Pełny tekst źródła

Streszczenie:

AbstractObjectives:To develop and characterise an experimental model of recurrent laryngeal nerve injury for the study of viral gene therapy.Methods:Twenty rats underwent unilateral recurrent laryngeal nerve injury. After vocal fold mobility was observed, larynges were serially sectioned, and immunohistochemical techniques were employed to stain for neurofilament and motor endplates in order for a blinded investigator to determine the percentage of nerve–endplate contact, as a histological indicator of an intact neuromuscular connection.Results:All animal procedures resulted in complete, ipsilateral vocal fold paralysis that recovered by three weeks. The mean nerve–endplate contact percentage was 11.6 per cent at one week, 53.9 per cent at two weeks, 88.6 per cent at three weeks, 81.7 per cent at four weeks and 86.6 per cent at five weeks. The differences between results at week one and week three were statistically significant (p < 0.01). The mean nerve–endplate contact percentage on the control side was 86.8 per cent.Conclusions:There was a dramatic, measurable decrease in nerve–endplate contact percentage following crush injury to the recurrent laryngeal nerve. Spontaneous recovery was observed by three weeks post-injury. This model will be used to investigate the potential therapeutic role of viral gene therapy for the treatment of recurrent laryngeal nerve injury.

Style APA, Harvard, Vancouver, ISO itp.

Więcej źródeł

Rozprawy doktorskie na temat "Endplate"

Hu, Ying. "Robustness of flexible endplate connections under fire conditions". Thesis, University of Sheffield, 2010. http://etheses.whiterose.ac.uk/14969/.

Pełny tekst źródła

Streszczenie:

Worldwide interest in how to prevent the progressive collapse for tall and large buildings under exceptional loading conditions was heightened by the collapse of the twin towers at the World Trade. The performance of steel-framed structures subjected to fire loading is heavily reliant on the interaction between structural members such as columns, slabs and beams. The implicit assumption in fire engineering design is that bolted connections are able to maintain the structural integrity for a large and tall building under fire conditions. Unfortunately, evidence from the collapse of the World Trade Centre towers and full scale fire tests at the BRE Cardington Laboratory indicates that connections may be particularly vulnerable during both heating and cooling. Hence, this PhD research is focused on structural performance of simple steel connections under fire conditions, particularly the interaction mechanism between non-ductile and ductile components in a connection and connection failure mechanism in a steel-framed structure subjected to fire loading. The research involved experimental testing of simple steel connections and components (structural 8.8 bolts) at elevated temperatures. High temperature tests on structural bolts demonstrated two modes of failure at elevated temperatures: bolt breakage and thread stripping. In order to prevent the thread stripping in a connection, the manufacturing process of bolts and nuts has been investigated and the 'overtapping' of nut threads to accommodate the (zinc) coating layer for corrosion resistance has been indentified as a primary reason resulting in this premature failure between bolts and nuts. Experimental tests on endplate connections revealed the ductility of these connections to decrease at high temperatures, which might hinder the development of catenary actions in fire if plastic hinges are attempted to be formed within the connection zones. Component-based modelling and finite element simulation have been utilized for investigation of the performance of these connections. An improved component-based model has been developed which includes nonductile (brittle) components (bolts and welds) into a connection model with a reasonable assumption of their failure displacements, based on experimental tests. This model also features vertical components for consideration of shear response of these connections in fire. The component-based connection model has been used in a sub-frame structure and a parametric study demonstrates that a connection may fail due to a lack of rotational capacity (failure of bolts or welds) in a structure exposed to a fire. Therefore, partial depth endplate connections are recommended to be fireprotected to prevent the failure of these brittle components. Alternatively, ensuring the strength of brittle components (bolts and welds) is higher than that of other components in each bolt row is necessary to achieve the ductile failure mechanism of simple connections. Based on the experimental tests, component-based connection modelling and finite element simulation, recommendations to improve the robustness of simple steel connections in fire have been presented.

Style APA, Harvard, Vancouver, ISO itp.

ZHOU, FENGFENG. "MODEL-BASED SIMULATION OF STEEL FRAMES WITH ENDPLATE CONNECTIONS". University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1119316578.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Pokharel, Rajib. "Structural Optimization of Offset Derrick Structure and Channel Endplate Connections Study". Thesis, University of Louisiana at Lafayette, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10002396.

Pełny tekst źródła

Streszczenie:

This study is intended to focus on the optimization of offset derrick structures and to present a novel connection details for derrick structures. The overall goal of this study is to improve performance, ease fabrication, and reduce material and labor costs associated with derrick structures, and study the performances of Double Channel Endplate and Single Channel Endplate Connections using Finite Element Method (FEM) analysis.

Optimization of derrick structure is carried out by modeling different bracing systems with different parameters of design, for example, vertical panel height, bracing type, buckling restraint, and member orientation to come to optimum result in terms of structural weight, lateral stiffness, and number of joints. Eccentric bracing system, 2X-bracing system, X-bracing system, and K-bracing system are studied and comparisons are made among structures with similar vertical panel height to come to efficient geometry of that category. A Double Channel and Single Channel Endplate connection are developed and modeled to see the stress distribution, moments, and rotation capacities. Finally, behavioral plots (moment-rotation) are modeled to rate the performance of connections.

Structures with relatively shorter force path, uniform internal force distribution, and small internal forces are found to respond well and they are stiff, economical, and elegant as well. For 2X-bracing system, efficiency of offset derrick structure to resist the load is found to decrease for both small and large vertical panel height and optimum height was found in between. For this study, the optimum height was 20 ft. for 2X-bracing system. Thickness, and overlapping length of channel plate is found important for in-plane capacity of connection while stiffeners are more important for out-of-plane capacity. Connection is found to have higher in-plane bending stiffness than for out-of-plane.

Style APA, Harvard, Vancouver, ISO itp.

Zehra, Uruj. "Changes in the endplate and their relationship to intervertebral disc degeneration". Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.685354.

Pełny tekst źródła

Streszczenie:

Low back pain represents a significant financial burden to society. The major costs are associated with chronic back pain which often arises as a result of intervertebral disc degeneration. Discs lie between the vertebrae and are separated fi'om them by a cartilaginous and bony endplate. The endplate is vital for intervertebral disc health because of its role in load-transfer and disc nutrition. Consequently, changes to the endplate due to ageing or injury may adversely affect the disc and contribute to varying forms of degeneration.

Style APA, Harvard, Vancouver, ISO itp.

Mok, Pik-sze, i 莫碧詩. "Lumbar endplate and modic changes, epidemiology, determinants and pain profiles in southern Chinese". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206737.

Pełny tekst źródła

Streszczenie:

Intervertebral disc(IVD) degeneration is associated with low back pain (LBP).Despite the endplates are located adjacent to the IVD, the phenotypes of endplate and vertebral bone marrow changes remain unclear. The objective of this study is to assess the prevalence and the associated determinants of these phenotypes of the lumbar spine. 2449 Southern Chinese subjects (aged 10 –88 years) undergone sagittal T2-weighted magnetic resonance imaging (MRI)examination to assess the presence of endplate and vertebral bone marrow changes including Schmorl’s nodes (SN) and Modic changes (MC),respectively, and scored for additional radiographic features over the lumbar spine. Subjects’ demographics, clinical profile, and functional status were assessed by means of standardized questionnaires. Anovel6-domain SN morphological classification based on MRI was developed to further analyze the characteristics of SN and its association with disc degeneration (DD). The prevalence of SN was 16.4%. Males, taller and heavier individuals had a significantly increased likelihood of SN. Overall presence of SN was age-independent, but was significantly associated with DD, and linearly correlated with increase in severity of DD. SN were particularly associated with severe DD at the upper two lumbar levels (L1/2 – L2/3). Based on the SN classification system, specific SN characteristics and endplate linkage patterns were found. Of these, two SN types were identified:“Typical SN” and “Atypical SN”. “Typical SN” were those smaller size SN with various shapes that were frequently located at caudal endplates of L1/2–L3/4disc levels. One variant of “Atypical SN” were those rectangular shape SN, which predominantly located at the posterior region of the rostral endplates of L1/2–L2/3disc levels. The other variant of “Atypical SN” was larger size SN with irregular shape that frequently presented at the L4/5endplates, they were also likely to be associated with marrow changes. Despite “Atypical SN” only entailed 8.3% of all identified SN, they were associated with increased severity of DD than “Typical SN”. Although the overall prevalence of MC among Southern Chinese was low (5.8%), after adjustments for other confounding factors, the presence of MC was associated with the presence and severity of LBP. Interestingly, the determinants of MC at upper (L1/2 – L3/4) and lower (L4/5 – L5/S1) lumbar showed distinct difference. The presence of MC at upper lumbar levels was only associated with the disc integrity only (i.e. the presence of disc displacement, and DD score), while the presence of MC at the lower levels, apart from the disc integrity, was also associated with increasing age, the presence of SN, smoking and obesity status. This study is the largest MRI study assessing the phenotypes of endplate and vertebral bone marrow changes in-vivo. The prevalence and distribution of SN and MC vary throughout the lumbar spine, and there are level and region-specific variations regarding these phenotypes. Determinants of SN and MC may be similar but do vary, suggesting distinct etiological factors. Findings of this study broaden the understanding of the various phenotypes of the lumbar spine and its association with DD.
published_or_final_version
Orthopaedics and Traumatology
Doctoral
Doctor of Philosophy

Style APA, Harvard, Vancouver, ISO itp.

LIMA, LUCIANO RODRIGUES ORNELAS DE. "BEHAVIOUR OF STRUCTURAL STEEL ENDPLATE JOINTS SUBJECTED TO BENDING MOMENT AND AXIAL FORCE". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2003. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=4165@1.

Pełny tekst źródła

Streszczenie:

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Tradicionalmente, o projeto de pórticos em estruturas de aço assume que as ligações viga-coluna são rígidas ou flexíveis. As ligações rígidas, onde não ocorre nenhuma rotação entre os membros conectados, transferem não só momento fletor, mas também força cortante e força normal. Por outro lado, as ligações flexíveis são caracterizadas pela liberdade de rotação entre os membros conectados impedindo a transmissão de momento fletor. Desconsiderando- se estes fatos, sabe-se que a grande maioria das ligações não possuem este comportamento idealizado. De fato, a maioria das ligações transfere algum momento fletor com um nível de rotação associado. Estas ligações são chamadas semi-rígidas e seu dimensionamento deve ser executado de acordo com este comportamento estrutural real. Porém, algumas ligações viga-coluna estão sujeitas a uma combinação de momento fletor e esforço axial. O nível de esforço axial pode ser significativo, principalmente em ligações de pórticos metálicos com vigas inclinadas, em pórticos não-contraventados ou em pórticos com pavimentos incompletos. As normas atuais de dimensionamento de ligações estruturais em aço não consideram a presença de esforço axial (tração e/ou compressão) nas ligações. Uma limitação empírica de 5 por cento da resistência plástica da viga é a única condição imposta no Eurocode 3. O objetivo deste trabalho é descrever alguns resultados experimentais e numéricos para estender a filosofia do método das componentes para ligações com ações combinadas de momento fletor e esforço axial. Para se cumprir este objetivo, quinze ensaios foram realizados e um modelo mecânico é apresentado para ser usado na avaliação das propriedades da ligação: resistência à flexão, rigidez inicial e capacidade de rotação.
Traditionally, the steel portal frame design assumes that beam-to-column joints are rigid or pinned. Rigid joints, where no relative rotations occur between the connected members, transfer not only substantial bending moments, but also shear and axial forces. On the other extreme, pinned joints, are characterised by almost free rotation movement between the connected elements that prevents the transmission of bending moments. Despite these facts, it is largely recognised that the great majority of joints does not exhibit such idealised behaviour. In fact, many joints transfer some bending moments associated with rotations. These joints are called semi-rigid, and their design should be performed according to their real structural behaviour. However, some steel beam-to-column joints are often subjected to a combination of bending and axial forces. The level of axial forces in the joint may be significant, typical of pitched-roof portal frames, sway frames or frames with incomplete floors. Current standard for steel joints do not take into account the presence of axial forces (tension and/or compression) in the joints. A single empirical limitation of 5 percent of the beam s plastic axial capacity is the only enforced provision in Annex J of Eurocode 3. The objective of the present work is to describe some experimental and numerical results to extend the philosophy of the component method to deal with the combined action of bending and axial forces. To fulfil this objective a set of sixteen specimens were performed and a mechanical model was developed to be used in the evaluation of the joint properties: bending moment resistance, initial stiffness and rotation capacity.

Style APA, Harvard, Vancouver, ISO itp.

Wang, Zhiyu. "Hysteretic response of an innovative blind bolted endplate connection to concrete filled tubular columns". Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/14489/.

Pełny tekst źródła

Streszczenie:

Concrete filled steel tubular (CFT) columns can employ the advantages of both materials: steel and concrete. Connection to such columns, however, is problematic. This is especially so if the required connection is both bolted and moment-resisting. To address this issue, a novel blind-bolted and moment-resisting connection to CFT column has been developed. This connection uses an innovative blind-bolt, introduced in previous research at the University of Nottingham and is termed the Extended Hollobolt (EHB). The EHB has been developed to provide sufficient tensile resistance and stiffness for the connection to develop resistance to moment. Previous research work has studied the performance of this connection under monotonic loading. The performance of such connection under cyclic loading, however, is not yet investigated. The work presented in this thesis addresses this gap in knowledge. This thesis reports on a series of full scale testing of joints consisting of beam endplates connected to CFT columns using this blind bolt. The test connections were constructed with relatively thick endplate so as to isolate the CFT column and the blind bolt as the relatively weak elements in the connection system. This study focuses on the behaviour of the connections with principal failure modes attributed by the blind bolt and the CFT column. The experiments were conducted to obtain insights into the hysteretic moment-rotation relationship, available ductility & energy dissipation capacity, observe typical failure modes, and develop relevant understandings of the Extended Hollobolt-endplate connection subjected to cyclic loading. The selected connection details were chosen to examine the influential parameters of the joint hysteretic moment-rotation behaviour. From the experimental results, two representative failure modes, bolt fracture and column face bending failure, were observed and categorized in relation to the connection configuration. The connection behaviour are described and compared with respect to the influences of bolt grade, cyclic loading procedure, tube wall thickness and concrete grade. Based on the experimental hysteretic moment-rotation relationships, an evaluation of the cyclic characteristics and an analysis' of the cumulative damage were carried out for the two representative connection categories. The joint hysteretic moment-rotation response was assessed in term of degradations of strength, stiffness, ductility, and energy dissipation. The use of damage levels and stages in the interpretation of damage evolutions for the connection behaviour is also described in this thesis. The findings of cumulative damage analysis suggest that the energy based cumulative damage index outweighs the other indices in characterizing the progressive damage process of the connections in this study. This is especially the case for those related to hysteresis loops at repeated cycles of each loading amplitude. Following the experimental study, 3D nonlinear finite element models of the connections were developed to analyse the mechanical response of the connection. The comparison of the numerical and experimental moment-rotation envelope curve is discussed with respect to related geometric and material parameters. The connection failure modes and displacement distributions were further examined as a supplement to the experimental findings that were necessarily limited by instrumentations. This work also presents mathematical models for the hysteretic moment-rotation relationships simulating the loading, unloading and reloading segments of the hysteresis loops. Characterizing parameters were introduced to, allow for the softening slope, linear segment slope, and degradations of strength and energy dissipation. This study concluded that the proposed finite element model simulates well the behaviour of the connection with good prediction of the moment-rotation envelope curves and of the failure mode. It is also concluded that the proposed mathematical models define well the non-linear loading and unloading paths with reasonable accuracy. It is finally claimed that the Extended-Hollobolt endplate connection provides a stable improvement in strength and stiffness under cyclic loading compared with other similar connections.

Style APA, Harvard, Vancouver, ISO itp.

Jones, S. V. P. "The characteristics of endplate ion channel block produced by disopyramide and two erythrina alkaloids". Thesis, University of Strathclyde, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372105.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Czamanski, Jessica. "The Differences Between the Energy Metabolism of the Annulus Fibrosus and the Nucleus Pulposus Cells of the Intervertebral Disc". Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_theses/49.

Pełny tekst źródła

Streszczenie:

Back pain is one of the most common physical conditions in the United States, for which approximately 15% of the population will visit a doctor every year. The most common type of back pain is low back pain (LBP) and millions of dollars are spent every year healthcare are a due to LBP. Although poorly understood, low back pain has been associated to interveterbral disc (IVD) degeneration. The IVD is an important structure that helps maintaining normal skeletal support. It is composed of three different tissues called the annulus fibrosus (AF), and the nucleus pulposus (NP), attached to a cartilage endplate (CEP) at its top and bottom surfaces. The AF tissue is composed of chondrocyte-like cells, while the NP tissue is composed of notochordal cells at a young age, which are replaced by mature NP cells later in life. Common signs of degeneration are the inability to maintain extracellular matrix integrity and calcification of the cartilage endplate. Extracellular matrix synthesis and cartilage endplate calcification are closely related to production of adenosine triphosphate (ATP) or energy metabolism of the cells. AF and NP tissues are known to be structurally and compositionally different; therefore it is believed that their metabolic pathways are also distinct. The objective of this study was to determine the differences between AF and NP cells, specifically in their energy metabolism with and without dynamic loading.

Style APA, Harvard, Vancouver, ISO itp.

Gosling, Niki. "Development and analysis of apatite-mullite glass-ceramic scaffolds : towards tissue engineering of the vertebral endplate". Thesis, University of York, 2014. http://etheses.whiterose.ac.uk/5960/.

Pełny tekst źródła

Streszczenie:

Calcification of the vertebral endplate (EP) is a key factor relating to the onset of degenerative disc disease, a primary influencer of lower back pain which carries substantial social and economic burden. The aim of the current project was to investigate the feasibility of using apatite-mullite glass ceramic (AM-GC) to provide a bioactive scaffold for tissue engineering applications in the region of the vertebral EP. Consequently this material was fully characterised with regard to the natural tissues from a number of functional perspectives, mechanical, compositional, biological and those factors relating to the in vivo mass transfer of nutrients. Scaffolds were manufactured via a novel particle sintering approach to provide a range of porous substrates. Insight into the potential for tissue engineering the complex structures of the EP were provided using primary human mesenchymal stem/stromal cells (MSCs) due to their capacity to differentiate into both the osteogenic and chondrogenic lineages that constitute the natural EP structure. The results identified a novel heating regime able to produce AM-GC scaffolds mechanically suitable for EP application displaying mean pore size characteristics able to promote osteointergration with natural bone. Though identified as a bulk nucleating system substantial influence on surface composition was attributed to particle size fractions, with the 45-90 µm range deemed most suitable for bone applications. The differentiation capacity of MSCs on scaffolds utilising this particle size range exhibited excellent in vitro biocompatibility characteristics. Demonstrating a clear osteoconductive capacity along with the ability to support chondrogenic micro-mass culture, inferring potential for future development of in vitro AM-GC based EP constructs. To facilitate this future goal a permeability testing methodology was developed to replicate the in vivo nutrient mass transfer environment of the natural tissue. Initial testing proved this system fit for purpose allowing future in vitro engineered constructs to be comparatively analysed against natural EP mass transfer characteristics. Ensuring that future tissue engineering efforts in the region of the vertebral EP provide the necessary nutrient supply functionality essential for successful clinical application.

Style APA, Harvard, Vancouver, ISO itp.

Więcej źródeł

Książki na temat "Endplate"

Lucha, P. K. Stress distributions in fillet welded beam to endplate connections. Manchester: UMIST, 1993.

Znajdź pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Basir, Mohd N. Mohd. Application of fracture mechanics to fillet welded beam to endplate (extended) connections. Manchester: UMIST, 1997.

Znajdź pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Racicot, Janice. The amount of variance within endplate morphology of motor units in the rat plantaris muscle. Sudbury, Ont: Laurentian University, Behavioural Neuroscience Program, 1992.

Znajdź pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

The extremities: Muscles and motor points. Wyd. 6. Philadelphia: Lea & Febiger, 1993.

Znajdź pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Leung, Doris G. Other Proven and Putative Autoimmune Disorders of the Peripheral Nervous System. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199937837.003.0098.

Pełny tekst źródła

Streszczenie:

Myasthenia gravis is in most cases an autoimmune disorder of the neuromuscular junction in which antibodies are directed at nicotinic acetylcholine receptors or other synaptic proteins, such as the MusK protein that is involved in the formation of the formation and maturation of the motor endplate. Less commonly, myasthenia gravis can result from antibodies directed to presynaptic calcium channels as a side effect of paraneoplastic antibodies (Lambert-Eaton syndrome) or from a developmental paucity of acetylcholine receptors in the neonatal form of the disease. Treatment is usually a combination of aceetylcoholinesterase inhibitors such as pyridostigmine to prolong the life of acetylcholine released at the neuromuscular junction and/or drugs such as corticosteroids aimed at reducing inflammation.

Style APA, Harvard, Vancouver, ISO itp.

Deadly Endplay. Master Point Press, 2011.

Znajdź pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

OBE, Mr Andrew M. Robson. Bridge Lessons: Endplay & Squeeze. CreateSpace Independent Publishing Platform, 2011.

Znajdź pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Bridge Endplays for Everyone, Even You! Master Point Press, 2008.

Znajdź pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Endplays And Coups (Test Your Bridge Technique). Master Point Press, 2004.

Znajdź pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Card Play Made Easy 1: Safety Plays & Endplays (Card Play Made Easy). Trafalgar Square Publishing, 1997.

Znajdź pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Części książek na temat "Endplate"

Löscher, Wolfgang N. "Neuromuscular Transmission: Endplate Disorders". W Atlas of Neuromuscular Diseases, 235–46. Vienna: Springer Vienna, 2014. http://dx.doi.org/10.1007/978-3-7091-1605-0_10.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Feldman, Eva L., James W. Russell, Wolfgang N. Löscher, Wolfgang Grisold i Stefan Meng. "Neuromuscular Transmission: Endplate Disorders". W Atlas of Neuromuscular Diseases, 263–73. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-63449-0_13.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Molenaar, P. C., i R. L. Polak. "Resting Release of Acetylcholine at the Motor Endplate". W Advances in Behavioral Biology, 481–87. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4684-5194-8_46.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Miledi, R., P. C. Molenaar i R. L. Polak. "Evoked Release of Acetylcholine at the Motor Endplate". W Advances in Behavioral Biology, 489–97. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4684-5194-8_47.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Barim, Menekse Salar, Richard F. Sesek, M. Fehmi Capanoglu, Wei Sun, Sean Gallagher, Mark C. Schall i Gerard A. Davis. "Quantifying Vertebral Endplate Degeneration Using the Concavity Index". W Advances in Intelligent Systems and Computing, 734–41. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-96083-8_88.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Heilbronn, Edith. "Diseases and Induced Lesions of the Neuromuscular Endplate". W Pathological Neurochemistry, 241–84. Boston, MA: Springer US, 1985. http://dx.doi.org/10.1007/978-1-4757-0797-7_13.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Bahaari, Mohammed R. "A Study of M-Φ Behaviour of Flush Endplate Connections". W Trends in Structural Mechanics, 245–54. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5476-5_24.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Waser, P. G. "On Receptors in the Postsynaptic Membrane of the Motor Endplate". W Ciba Foundation Symposium - Molecular Properties of Drug Receptors, 59–83. Chichester, UK: John Wiley & Sons, Ltd., 2008. http://dx.doi.org/10.1002/9780470719763.ch5.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Volle, Robert L. "Nicotinic Receptors in the Motor Endplate and in Sympathetic Ganglia". W Tobacco Smoking and Nicotine, 317–23. Boston, MA: Springer US, 1987. http://dx.doi.org/10.1007/978-1-4613-1911-5_20.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Ma, Hong Wei, Chong Du Cho, Qiang Pan i Hyeon Gyu Beom. "A Study on the Lower Flanges Fracture of Endplate Bolted Connection". W Experimental Mechanics in Nano and Biotechnology, 983–86. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-415-4.983.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Streszczenia konferencji na temat "Endplate"

Chung, Tien-Tung, Huan-Ruei Shiu, Chi-Chang Chen, Chin-Te Lin, Kuei-Han Chen i Chih-Yun Lu. "Endplate Design and Analysis of Fuel Cells". W ASME 2009 7th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2009. http://dx.doi.org/10.1115/fuelcell2009-85151.

Pełny tekst źródła

Streszczenie:

Endplate design is important to the structural safety and the performance of the proton exchange membrane (PEM) fuel cells. In this paper, an organized design and analysis method is proposed to improve the endplate design. The 3D model for finite element analysis is constructed automatically by a CAD software with a parametric program through GUI interfaces. This model includes endplates, carbon plates, O-rings, gas diffusion layers (GDLs), and membrane electrode assemblies (MEAs). Then a series of finite element analysis are executed to analyze the structural behavior of PEM fuel cells. Structural boundary conditions and contact pairs are also applied into the meshed model. The positions of tie-bolts and parameters of endplate design are changed to improve the performance of PEM fuel cells through numerical optimization techniques. The structural behavior of key components is analyzed, including the compression ratio of GDLs, the sealing pressure of O-rings, and the structural safety of carbon plates. Results of analysis indicate that the shape of endplate affects the stack assembly pressure and contact behavior of PEM fuel cells. Proper shape of endplate can generate more uniform deformation of GDLs and avoid the leakage of fuels. With the changing design parameters of the endplate in the integrated design program, the optimum design that satisfies the design constraints and specifications can be found. According to the research conclusion, the proposed design and analysis method is helpful in determining the key dimensions for endplates or other components of PEM fuel cells.

Style APA, Harvard, Vancouver, ISO itp.

Kale, Shreedhar P., Noshir A. Langrana i Thomas Edwards. "Effects of Endplate Curvature on Stresses in a Vertebral Motion Segment: Finite Element Analysis". W ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60429.

Pełny tekst źródła

Streszczenie:

The vertebral endplates of the lumbosacral spine have various degrees of concavity and/or convexity. Several investigators including Seenivasan G., Goel, V. K., 1994, Liebschner et al, 2003, etc have performed finite element analysis on the vertebral bones, but the endplate curvatures are not included. Therefore, the effect of morphological details of the endplate curvatures on the stress distribution is unknown. Differences in these curvatures will increase stress in some regions and decrease stress elsewhere as the spine is compressed. In our previous study [Kale et al, 2003], lumbar vertebral endplate curvatures in the anterior-posterior and medial-lateral directions on human cadaver lumbar vertebrae were measured. The measurements were carried out using a reverse engineering instrument, built at Rutgers University [Hsieh et al, 2002]. Six sets of measurements (on human male-female L4 lower to S1 upper endplates) were performed. The data was later used in a linear elastic cylindrical model containing cortical shell and trabecular core. The model then was modified to a more accurate model, with more realistic, characteristic kidney shaped cross section (obtained from equation by Mizrahi et al, 1993) and linearly varying height. The endplates were assigned curvatures extracted from our human cadaver data. FEA, done on both the models, showed that the endplate curvatures and their location had significant effect on the stress distribution in the vertebral bone. In the current study we have extended our bone model into a motion segment and have investigated the effects of the curvatures on the stresses in the motion segment.

Style APA, Harvard, Vancouver, ISO itp.

Kale, Shreedhar P., Noshir A. Langrana, Casey K. Lee i Kenneth J. Kopacz. "A Study on Human, Chimpanzee and Canine Lumbar Vertebral Endplates". W ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-43557.

Pełny tekst źródła

Streszczenie:

Vertebral endplates of the lumbosacral spine have various degrees of concavity and/or convexity. Little information is available in the literature on accurate measurement of morphometry of the vertebral endplates of the lumbosacral spine and on biomechanical significance of the curvature. In this study, lumbar vertebral endplate curvatures in anterior-posterior and medial-lateral directions were measured. Human males-females, chimpanzees and canine lumbar endplates were scanned and quantified. Finite Element Analysis (FEA) was performed on endplates and the effects of location of maximum curvature depth on the stress distribution were investigated.

Style APA, Harvard, Vancouver, ISO itp.

Lazzari, Rafaela Radünz, Lara Justine da Silva, Tarcísio Gelaim i Dalmedson Gaúcho R. de Freitas Filho. "Simulation of Different Endplate Configurations' Efficiency". W 26th SAE BRASIL Inernational Congress and Display. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2017. http://dx.doi.org/10.4271/2017-36-0226.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Wu, Yongren, John Glaser i Hai Yao. "Effects of Endplate and Mechanical Loading on Solute Transport in Intervertebral Disc". W ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-193111.

Pełny tekst źródła

Streszczenie:

The intervertebral disc (IVD) is the largest cartilaginous structure in human body that contributes to flexibility and load support in the spine. To accomplish these functions, the disc has a unique architecture consisting of a centrally-located nucleus pulposus (NP) surrounded superiorly and inferiorly by cartilage endplates (CEP) and peripherally by the annulus fibrosus (AF). Disc degeneration is strongly linked to low back pain. Poor nutrient supply has been suggested as a potential mechanism for disc degeneration. Previous theoretical studies have shown that the distributions of nutrients and metabolites (e.g., oxygen, glucose, and lactate) within the IVD depended on tissue diffusivities, nutrient supply, and cellular metabolic rates [1, 2]. Based on a multiphasic mechano-electrochemical finite element model of human IVD [3], our recent theoretical study suggested that the mechanical loading has little effect on small solute transport (e.g., glucose), but significantly affects large solute transport (e.g., growth factor). The objective of this study was to further develop the multiphasic finite element model of IVD by including the cartilage endplate and considering the nutrient consumption of disc cells. Using this model, the effects of endplate and mechanical loading on solute transport in IVD were examined.

Style APA, Harvard, Vancouver, ISO itp.

Zahmatkesh, F., i E. Talebi. "The Performance of Bolted Slant Endplate Connections Subjected to Temperature Increase". W ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2010. http://dx.doi.org/10.1115/esda2010-24720.

Pełny tekst źródła

Streszczenie:

In this paper the main goal is to evaluate the vertical and slant bolted endplate connections performance in steel moment frame structures under thermal effect in elastic field, and by a finite element software. the connections are simulated to complete and verify simple modeling of analytical and numerical analysis of the behavior of vertical and slant bolted endplate connections due to increase in temperature. The results that are obtained from performance of a vertical bolted endplate connection and a slant bolted endplate connection due to increase in temperature will be compared.

Style APA, Harvard, Vancouver, ISO itp.

Williams, J. R., R. N. Natarajan i G. B. J. Andersson. "Prediction of Endplate Bulging With and Without Inclusion of Physiological Swelling Pressure and Strain Dependent Permeability and Porosity". W ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-59409.

Pełny tekst źródła

Streszczenie:

Finite element models were used to understand how changes in physiological factors such as swelling pressure and strain dependent permeability alters the biomechanical characteristics of lumbar discs under compressive loads. Exclusion of these physiological factors increased endplate stresses, reduced endplate bulge and reduced nucleus and annulus stresses.

Style APA, Harvard, Vancouver, ISO itp.

Beattie, E. E., J. H. Yoder, S. M. Moon, E. J. Vresilovic, D. M. Elliott i A. C. Wright. "Quantification of intervertebral disc cartilaginous endplate morphology using MRI". W 2012 38th Annual Northeast Bioengineering Conference (NEBEC). IEEE, 2012. http://dx.doi.org/10.1109/nebc.2012.6206983.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Buckley, Jenni M., i Tony M. Keaveny. "Sensitivity of Vertebral Compressive Strength to Endplate Loading Distribution". W ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60827.

Pełny tekst źródła

Streszczenie:

For a prescribed set of resultant loads, there is uncertainty in vertebral strength due to the unknown nature of the boundary conditions imposed by the disc along the bony endplate. Patient-specific techniques for predicting vertebral strength do not include information regarding the disc-vertebral body interaction since the physical condition of the disc is difficult to diagnose using conventional radiographic techniques, such as CT or MRI. It is unknown whether this omission introduces a large source of error in strength predictions. Thus, quantifying the uncertainty associated with the nature of these boundary conditions is essential for the development of more accurate techniques for in vivo fracture risk prediction.

Style APA, Harvard, Vancouver, ISO itp.

Cheng, Liu C., Jovauna M. Currey, Ashin Modak, Hyun Kyu Han, R. Trigg McClellan, Murat Pekmezci, Jenni M. Buckley i Christopher P. Ames. "Comparison of Mechanical Characteristics of Deployment for Expandable vs. Fixed Interbody Cages: Implications for Premature Clinical Failures". W ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19129.

Pełny tekst źródła

Streszczenie:

Both expandable and non-expandable interbody cage designs are available to surgeons for cases involving spinal reconstruction and stabilization following single level lumbar corpectomy [1]. Different expandable cage designs are on the market [2], but all involve a manual mechanism to intraoperatively adjust the compressive load applied by the cage against the vertebral body endplates. Non-expandable cages do not have such a mechanism, and surgeons rely on cutting the cage to the appropriate length to achieve a “press-fit.” The clinical reasoning behind the expandable cage design is that the adjustability of the device will allow the surgeon to achieve the maximum contact area between the cage and the vertebral endplate without “overstuffing” the interbody space and thus causing a sagittal-plane deformity.

Style APA, Harvard, Vancouver, ISO itp.

Raporty organizacyjne na temat "Endplate"

Chaudhary, R. I., i D. T. Williamson. Endplate Effectiveness for a NACA 0015 Airfoil. Fort Belvoir, VA: Defense Technical Information Center, styczeń 1992. http://dx.doi.org/10.21236/ada373750.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Jaffey, A. H., J. Gray, W. C. Bentley i J. L. Lerner. Measuring the absolute disintegration rate of a radioactive gas with a moveable endplate discharge counter (MEP) and theoretical calculation of wall effect. Office of Scientific and Technical Information (OSTI), wrzesień 1987. http://dx.doi.org/10.2172/6015856.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

CAPACITY EVALUATION OF EIGHT BOLT EXTENDED ENDPLATE MOMENT CONNECTIONS SUBJECTED TO COLUMN REMOVAL SCENARIO. The Hong Kong Institute of Steel Construction, wrzesień 2021. http://dx.doi.org/10.18057/ijasc.2021.17.3.6.

Pełny tekst źródła

Streszczenie:

The extended stiffened endplate (8ES) connection is broadly used in the seismic load-resisting parts of steel structures. This connection is prequalified based on the AISC 358 standard, especially for seismic regions. To study this connection’s behaviors, in the event of accidental loss of a column, the finite element model results were verified against the available experimental data. A parametric study using the finite element method was then carried out to investigate these numerical models’ maximum capacity and effective parameters' effect on their maximum capacity in a column loss scenario. This parametric analysis demonstrated that these connections fail at the large displacement due to the catenary action mode at the rib stiffener's vicinity. The carrying capacity, PEEQ, Von-Mises stress, middle column force-displacement, critical bolt axial load, and the beam axial load curves were discussed. Finally, using the Least Square Method (LSM), a formula is presented to determine the displacement at the maximum capacity of these connections. This formula can be used in this study's presented method to determine the maximum load capacity of the 8ES connections in a column loss scenario.

Style APA, Harvard, Vancouver, ISO itp.

Oferujemy zniżki na wszystkie plany premium dla autorów, których prace zostały uwzględnione w tematycznych zestawieniach literatury. Skontaktuj się z nami, aby uzyskać unikalny kod promocyjny!