• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 164
  • 37
  • 12
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 4
  • 3
  • 2
  • 2
  • 2
  • Tagged with
  • 287
  • 120
  • 95
  • 61
  • 60
  • 41
  • 38
  • 33
  • 31
  • 30
  • 25
  • 24
  • 24
  • 23
  • 23
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

The impact of cervical spine radiographs in the diagnosis and management of patients that presented with neck pain to the Chiropractic Day Clinic at the Durban University of Technology

Eloff, Louis Stephanus January 2016 (has links)
Submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic, Department of Chiropractic, Durban University of Technology, Durban, South Africa, 2016. / Background Literature has shown that clinical and radiological diagnoses do not always correlate in patients with neck pain (Ferrari and Russel, 2003; Peterson and Hsu, 2004). It is not known if this applies to the Chiropractic Day Clinic (CDC) at the Durban University of Technology (DUT) and if the radiological diagnosis leads to a change in the patient’s initial management plan. The impact of cervical spine plain film radiographs will therefore be investigated in the diagnosis and management of patients that presented with neck pain to the CDC at the DUT. It is also not known whether the reason for referral for cervical spine plain film radiographs is always indicated as per the indications in the clinic handbook and radiological referral guidelines. Objectives Objectives were: (1) To determine the suspected pre-radiographic clinical diagnosis and management of the selected clinical records prior to referral for cervical spine plain film radiography; (2) To record the reasoning to send for cervical spine plain film radiographic imaging and to establish whether these are in line with proposed guidelines for referral as found in the literature; (3) To determine the relationship between the suspected pre-radiographic clinical and the radiological diagnoses of patients with neck pain; (4) To determine the number of incidental findings in the selected patients’ plain film radiographs; (5) To determine any change in the pre-radiographic clinical diagnoses and management following radiological reporting of the selected patient’s plain film radiographs. Method This was a quantitative, retrospective, clinical study. The archives at the CDC at the DUT were searched for cervical spine plain film radiographs between 1 January 1997 to 31 December 2013 and these were matched with the corresponding clinical records. After applying the inclusion and exclusion criteria, 73 records were included in the study. The patient’s personal information was coded to ensure confidentiality (Appendix A) and specific clinical and radiological information was recorded (Appendix B). Statistical analysis included the use of frequency counts, percentages, mean, standard deviation and range for the descriptive objectives. Results A total of 73 clinical files and corresponding plain film radiographs were assessed. The mean age of the patients was 44 years. The gender distribution was 64.4% (n=47) females and 35.6% (n=26) males. The most frequent primary radiological diagnosis was loss of lordosis at 41.1% (n=30) followed by cervical spondylosis at 35.6% (n=26) and old cervical spinal trauma at 12.3% (n=9). Sixty four percent (n=47) of patients in this study were sent for cervical spine plain film radiographs after their initial clinical consultation. Reasons that are not considered relevant indications for plain film radiographic referral were present in 46.2% (n=34) of cases; these described non-specific mechanical disorders. The most common reason for plain film radiographic referral was due to positive orthopaedic tests 57.5% (n=42). A total of 27.4% (n=20) of clinical files reviewed had a change in their initial clinical diagnosis and 72.6% (n=53) of these patients had no change in diagnosis. All of the post-radiographic clinical diagnoses were non-specific mechanical conditions. Numerous treatment modalities were utilized by the students with the most common pre-radiographic treatment being soft tissue therapy at 63.0% (n=46). A total of 75% (n=55) of patients had a change of treatment after plain film radiographs were performed and spinal manipulative therapy (SMT) was the main treatment added in 41% of cases. Conclusion Cervical spine plain film radiographs have little impact on the diagnosis of patients with non-specific mechanical neck pain without red flags. It was however found that plain film radiographs had an impact on the management in the majority of cases, especially with an increase in SMT use after plain film radiographs. / M
192

Molecular Mechanisms of Notochord Vacuole Formation and Their Role in Zebrafish Development

Ellis, Kathryn Leigh January 2014 (has links)
<p>The notochord plays critical structural and signaling roles during vertebrate development. At the center of the vertebrate notochord is a large fluid-filled organelle, the notochord vacuole. While these highly conserved intracellular structures have been described for decades, little is known about the molecular mechanisms involved in their biogenesis and maintenance. Here we show that zebrafish notochord vacuoles are specialized lysosome-related organelles whose formation and maintenance requires late endosomal trafficking regulated by the vacuole-specific Rab32a, and H+-ATPase-dependent acidification. We establish that notochord vacuoles are required for body axis elongation during embryonic development and identify a novel role for notochord vacuoles in spine morphogenesis. Thus, the vertebrate notochord plays important structural roles beyond early development.</p> / Dissertation
193

Finite element modeling of bone cement for vertebroplasty

楊國泰, Yeung, Kwok-tai, Cathay. January 2003 (has links)
published_or_final_version / Orthopaedic Surgery / Master / Master of Philosophy
194

Fetal dosimetry from natural alpha emitters

Purnell, Sasha Justine January 2000 (has links)
No description available.
195

An Investigation of Rat Vertebra Failure Behaviour Under Uniaxial Compression Through Time-Lapsed Micro-CT Imaging

MORTON, JUSTIN 22 November 2013 (has links)
Osteoporosis is a bone degenerative disease characterized by reduced bone mass, quality and strength, along with changes in microarchitecture and increased incidence of fracture. The significant economic and social costs associated with osteoporotic fractures of the hip and spine have resulted in extensive research efforts directed towards developing an improved understanding of this disease, along with the relationships between osteoporotic bone degradation and fracture risk assessment. The current study investigates the failure behaviour of rat vertebral bodies collected from normal and osteoporotic donors based on the ovariectomized rat model (SHAM and OVX study groups, respectively), along with an additional control group intended to simulate postmenopausal patients with estrogen repletion (OVX+E study group). Simultaneous uniaxial compression testing and X-ray Micro-Computed Tomography (XμCT) were used to visualize and describe the failure behaviour of prepared vertebral body samples during mechanical testing, while providing standard measures of mechanical properties and bone geometry. In tandem with the incremental loading protocol required for simultaneous mechanical testing and XμCT imaging, a continuous loading protocol was also included. Three distinct failure behaviours were observed without bias in the three different study groups and two loading protocols. The primary and secondary failure modes involved fracture initiation in the direct vicinity of vascular apertures present in the dorsal surface of the cortical shell, with failure progression through the sample towards the ventral surface of the cortical shell (primary) or the cranial endplate (secondary). The tertiary failure mode involved localized rupture of the cranial endplate, likely resulting from end-effect related stress-concentrations. Diminished trabecular bone geometry (reduced BV/TV and Tb.N, along with increased Tb.Sp) was accompanied by reduced mechanical properties (reduced ultimate force and ultimate strength) in the OVX study group when compared with the SHAM and OVX+E study groups. Linear regression analyses revealed a shift in the determinants of failure initiation between the SHAM/OVX+E study groups and the OVX study group. In the SHAM and OVX+E study groups, ultimate force was best predicted by indices describing the vascular apertures present in the dorsal cortical shell. In the OVX study group, ultimate force was best predicted by indices describing trabecular bone geometry. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2013-11-21 19:07:38.661
196

Segmentace 3D obrazových dat na základě deformovatelných modelů / Segmentation of 3D image data based on deformable models

Klásek, Pavel January 2015 (has links)
This document deals with the pre-processing and the segmentation of human vertebrae from computed tomography 3D image data. It describes image registration and segmentation methods concretely and commonly used in image data processing during the automated spine canal localization process and the localization of each vertebrae centroid. The 3D deformable model development is described in the work together with the introduction to the previous state of art and the progress of vertebrae segmentation using 3D deformable models registration. This work presents the evaluation of the accuracy and the reliability from the segmentation and localization results.
197

The effects of flexion distraction on the segmental mobility and pain in chronic lumbar facet syndrome

31 July 2012 (has links)
M.Tech. / Purpose: To determine what effects flexion distraction will have on males with chronic lumbar facet syndrome, in reference to intersegmental range of motion and pain. Method: Thirty male participants with chronic lumbar facet syndrome received flexion distraction technique. The trail consisted of seven visits over two to three weeks. Treatment was performed on the first to sixth visit, readings and questionnaires were completed on the first, fourth and seventh visits. Data collection was concluded before treatment on the mentioned visits. Subjective data consisted of the Oswestry Disability Index (ODI) and the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2). Objective data included global lumbar range of motion measurements using the Baseline Digital Inclinometer, and segmental lumbar range of motion by means of the Radiographical Midplane Angle method. Results: Objectively, clinical significance of the intersegmental lumbar range of motion increased from the L1/L2 to the L4/L5 level (2.2% - 17.7%), but showed no statistical significance. In relation to the maximal motion possible at these levels, the increase in motion escalated from 0.8% at the L1/L2 segment to 9.2% at the L4/L5 segment. The global lumbar range of motion showed clinical significant increase in all of the ranges except for extension, however statistical significance was found in right lateral flexion only (p = 0.045). The greatest increase in motion was observed in left lateral flexion (15.72%) and a decrease in extension (3.72%) was illustrated. Subjectively, the group showed statistical significant improvement in both the SF-MPQ-2 (p = 0.000) and ODI (p = 0.000). Clinical meaningful change was noted throughout the subjective data, which resultantly showed a 66% and a 67% change in pain respectively. Conclusion: Flexion distraction has shown to have clinical significant effects on segmental and thus global range of motion, and great clinical meaningful change in pain levels and pain perception. Thus specific segmental mobilisation does affect the segmental motion.
198

The effect of cervical spine chiropractic adjustments on touch pressure threshold in patients with chronic cervical facet syndrome

05 February 2014 (has links)
M.Tech. (Chiropractic) / Purpose: The effectiveness of cervical spine adjustments for improving spinal function and relieving pain has been well established. However, the mechanisms responsible for these changes after spinal adjustments are still being researched. Further scientific evidence regarding the neurological and physiological effects following spinal adjustments is warranted. Evidence suggesting that spinal dysfunction has an effect on central neural processing is growing. A number of palpation from the first to the sixth visit. The seventh visit consisted of gathering data only. Results: Clinical and statistical improvements in the entire group were shown over the course of the treatment with regards to cervical spine range of motion, touch pressure threshold and neck pain and disability. Conclusion: The results show that lower cervical spine adjustments do have an effect on touch pressure threshold, cervical spine range of motion and neck pain and disability in patients with chronic cervical facet syndrome. Touch pressure threshold returned to optimal function, cervical spine range of motion increased and neck pain and disability decreased in all participants over time. authors have suggested that spinal dysfunction may lead to altered sensory input to the central nervous system (Murphy and Taylor, 2008). Aim: The aim of this study was to determine the effect of C6, C7 and T1 spinal adjustment therapy on those individuals with posterior neck pain due to chronic cervical facet syndrome and its influence on touch pressure threshold, neck pain and disability as well as cervical spine range of motion. Method: This study consisted of a single group of thirty participants between the ages of eighteen and fourty-five. The potential participants were examined and accepted according to the inclusion and exclusion criteria. The only method of treatment administered to each participant was cervical spine adjustments delivered to restricted C6, C7 and Tl segments in the lower cervical spine. Subjective and objective findings followed. Procedure: Treatment consisted of seven visits. Subjective and objective data was taken at the first, fourth and seventh visit. Objective data consisted of cervical spine range of motion readings taken using a Cervical Range of Motion measuring instrument (CROM), and touch pressure threshold results obtained via the Semmes Weinstein monofilaments. Subjective data was taken in the form of a Vernon Mior Neck Pain and Disability Index. Cervical spine adjustments were applied to restricted segments in the lower cervical spine (C6, C7, Tl), identified through motion
199

The immediate effect of a chiropractic adjustment on pressure pain threshold of a restricted cervical spine facet joint

19 June 2012 (has links)
M.Tech. / Purpose: The cervical facet joints have attracted relatively little attention as possible sources of neck pain and referred pain. Multiple authors have described the management of cervical facet joint pain but not the cause (Manchikanti et al., 2002). Method: This study consisted of one group of 100 participants. The participants were between the ages of 18 and 40 years. Potential participants were examined and accepted based on the inclusion and exclusion criteria. All the participants received a cervical spine adjustment. Objective and subjective readings were taken. Procedure: The participants were seen only once. The Visual Analogue Scale was completed by each participant before treatment. Algometer readings were taken over the most restricted cervical spine facet joint and cervical spine range of motion (CROM) machine readings were taken measuring the ranges of motion of the cervical spine. The participants received an adjustment to the most restricted cervical spine facet joint as determined by motion palpation. The CROM machine and algometer readings were taken again immediately after the adjustment and the algometer readings were taken again 10 minutes later. Results: In terms of subjective measurements based on the Visual Analogue Scale, all participants experienced clinically significant pain before starting the trial.In terms of objective measurements based on algometer readings, a clinically significant difference was found as the pressure pain threshold increases over a period of time. In terms of the CROM machine readings there was a clinical improvement from the pretreatment ranges of motion to the post-treatment ranges of motion. The algometer and CROM readings were statistically incomparable to begin with. Conclusion: The results proved that there was a statistical significant noted immediately after the adjustment and 10 minutes later, however, this does not mean much as thegroups were not comparable to begin with. A statistically significant difference was noted for all ranges of cervical spine motion (flexion, extension, right and left lateral flexion and rotation), thus showing that the cervical spine adjustment was successfully delivered to the restricted segments.
200

Constraints versus adaptations as contending evolutionary explanations of morphological structure : The giraffe (Giraffa Camelopardalis) head and neck as a heuristic model

Badlangana, Ludo Nlambiwa 01 December 2008 (has links)
The current study uses the head and neck of giraffe (Giraffa camelopardalis) as a model for tracking the course of evolutionary change. Gould (2002) has argued that there are three main avenues of evolutionary change that result in the genesis of new morphologies. These are phylogenetic constraints, structural or allometric scaling laws of form, and specific unique adaptations. It is well known that the unique characteristic of the giraffe is its extremely long neck and yet, it only has seven cervical vertebrae. To study the neck the vertebral body lengths of different aged giraffes were measured to determine the contribution of the cervical vertebrae to the total vertebral column. The vertebrae of several extant ungulates as well as those of fossil giraffids were used as a comparison with the giraffe. CT scans were used on several giraffe skulls to study the extent of the frontal sinus in the giraffe in an attempt to explain why the giraffe evolved such a large frontal sinus. The vertebral columns and skulls of several ungulates, including the okapi (Okapia johnstoni) were also used to compare with the results obtained from the giraffe. Immunohistochemistry was used to study the medulla and spinal cord sections of the giraffe to determine if the location and size of the nuclei remained unchanged to the basic ungulate or mammalian plan in spite of the unusually long neck, or if this long neck led to changes in the nuclei found in those regions. The results of these stains were all compared to the published literature available. Although more studies need to be conducted on other ungulates to conclusively determine why giraffe have evolved a long neck, overall the results showed that the anatomy giraffe head and neck remained true to the basic mammalian plan, with very little changing in terms of it morphology. The giraffe brain and spinal cord also resembled that of a typical ungulate. This leads to the conclusion that constraints and allometric scaling laws of form play a greater role than previously thought in the evolution of extreme morphologies.

Page generated in 0.0414 seconds