Search results for "Displacement"
showing 10 items of 433 documents
A novel boundary element formulation for anisotropic fracture mechanics
2019
Abstract A novel boundary element formulation for two-dimensional fracture mechanics is presented in this work. The formulation is based on the derivation of a supplementary boundary integral equation to be used in combination with the classic displacement boundary integral equation to solve anisotropic fracture mechanics problems via a single-region approach. The formulation is built starting from the observation that the displacement field for an anisotropic domain can be represented as the superposition of a vector field, whose components satisfy a suitably defined anisotropic Laplace equation, and the gradient of the Airy stress function. The supplementary boundary integral equation is …
Classification of Fragility Fractures of the Pelvis
2017
The characteristics of fragility fractures of the pelvis are different from pelvic fractures in adolescents and adults. There are specific fracture morphologies such as U- or H-shaped fractures of the sacrum and bilateral fractures. The classification systems of AO/ASIF and Young-Burgess reflect the trauma mechanism and the type of instability in high-energy pelvic injuries. Not all types of fragility fractures of the pelvic ring fit into these classification systems. A new, comprehensive classification (FFP classification) includes all morphologies of fragility fractures of the pelvis, whether acute or chronic. It provides a framework for how to look at these lesions. The first criterion o…
Forms of nostalgia in Henry James’s "The American Scene"
2018
Henry James was not a sentimental writer. However, in his later books we can find traces of repressed emotions and melancholy. One of the most intriguing literary documents showing the nostalgic strain in James is his collection The American Scene (1907), a record of the novelist’s return to the USA after a twenty-years-old absence. It contains various manifestations of James’s nostalgia – for example, his memories of New York and his melancholic recollections of the places connected with his youth. Also, it shows James’s convoluted rhetoric of memory as a space of repression and displacement as well as his unwillingness to address these issues in a direct fashion.
Computertomographie der Atelektase
1987
After breathing pure oxygen, total atelectasis of one lung was produced in ten dogs; its development and regression was followed by CT and by conventional radiology. 30 seconds after cessation of ventilation, it was possible to show a rise in CT density of the atelectatic lung from -764 +/- 32 HU to -739 +/- 49 HU. The average time from the cessation of ventilation to total atelectasis averaged 5.5 +/- 1.1 minutes. The earliest sign on conventional radiographs was often seen after 30 seconds and usually after 60 seconds and consisted of mediastinal displacement. Extensive atelectasis regressed in only one out of six animals within one hour after resuming ventilation. The experimental method…
Non-uniform displacement and strain between the soleus and gastrocnemius subtendons of rat Achilles tendon
2018
Achilles tendon (AT) comprises of 3 subtendons arising from the soleus (SOL) and the lateral (LG) and medial (MG) heads of the gastrocnemius muscle. While recent human studies show differential displacement within AT, these displacements have not been attributed to specific subtendons. We tested the hypothesis that the SOL and LG subtendons show differential displacement and strain during various combinations of SOL, LG, and MG excitations. Movement of knots, sutured onto SOL and LG subtendons of 12 Wistar rats, was videotaped, while the muscles were stimulated intramuscularly and ankle torque was assessed. When SOL only was stimulated, the plantar flexion torque was the smallest among the …
Comparison of motor strategies in sit-to-stand and back-to-sit motions between healthy and Alzheimer’s disease elderly subjects
2005
We studied the kinematics of shoulder displacement during sit-to-stand and back-to-sit in 6 healthy elderly subjects and six elderly subjects with mild to moderate Alzheimer's disease in order to elucidate the impact of Alzheimer's disease on motor planning and control processes. During sit-to-stand, Alzheimer's disease subjects reduced their forward displacement and started their upward displacement earlier than healthy elderly subjects. Furthermore, shoulder path curvatures were more pronounced for upward compared with downward displacement in healthy elderly group, in contrast with Alzheimer's disease group. Temporal analysis found that: 1) for both groups, profiles of velocity of sit-to…
New intramedullary locking nail for olecranon fracture fixation--an in vitro biomechanical comparison with tension band wiring.
2010
The aim of this study was to determine the difference in displacement of a newly designed intramedullary olecranon fracture fixation device compared with multifilament tension band wiring after 4 cycles and 300 cycles of dynamic continuous loading.In eight pairs of fresh-frozen cadaver ulnae, oblique olecranon fractures were created and stabilized using either newly designed intramedullary olecranon nail or multifilament tension band wiring. The specimens were then subjected to continuous dynamic loading (from 25 N to 200 N) using matched pairs of cadaveric upper extremities. The Wilcoxon test was used to determine statistical differences of the displacement in the fracture gap.After 4 cycl…
Skeletal features in patient affected by maxillary canine impaction
2013
Objective: To analyze the skeletal features of patients with maxillary canine impaction. Material and Methods: The complete pre-treatment records of 1674 orthodontic patients were examined. From the subjects with maxillary impacted canine 12 patients were excluded , remaining 108. The subjects with maxillary impacted canine were divided into two study groups: a palatally displaced canine group (PDCG) (77 patients) and a buccally displaced canine group (BDCG) (31 patients). The values of the skeletal features measured on the lateral cephalometric radiograph were compared with a control group (CG) of 121 subjects randomly selected from the initial sample without maxillary canine impaction. Th…
Dynamic biomechanical analysis of different olecranon fracture fixation devices--tension band wiring versus two intramedullary nail systems: an in-vi…
2007
Abstract Background. The aim of this study was to develop a test-setup with continuous angle alteration to imitate joint motion for the evaluation of 3 different olecranon fracture fixation devices. Methods. Twenty-one fresh cadaver upper extremities underwent olecranon fracture by the means of transverse osteotomy and received 3 different fixation systems. Group 1: Tension band wiring according to Weber. Group 2: XS-nail with 9 holes, all locked with 2 mm threaded K-wires. Group 3: Olecranon Nailing System with 90 mm length, locked with 2.7 mm screws, a variable angle locking hole for the proximal fragment and a proximal locking end cap. The servo-pneumatical test stand worked with a rotat…
Predictive Score Card in Lumbar Disc Herniation: Is It Reflective of Patient Surgical Success after Discectomy?
2016
Does the Finneson–Cooper score reflect the true value of predicting surgical success before discectomy? The aim of this study was to identify reliable predictors for surgical success two year after surgery for patients with LDH. Prospective analysis of 154 patients with LDH who underwent single-level lumbar discectomy was performed. Pre- and post-surgical success was assessed by the Oswestry Disability Index (ODI) over a 2-year period. The Finneson-Cooper score also was used for evaluation of the clinical results. Using the ODI, surgical success was defined as a 30% (or more) improvement on the ODI score from the baseline. The ODI was considered the gold standard in this study. Finally, the…