Search results for "spin"
showing 10 items of 5044 documents
Bestimmung der Knochenqualität vor Wirbelsäuleninstrumentation - Stellenwert verschiedener in vivo-Methoden
2008
OBJECTIVE: The present investigation should elucidate which assessment technique for bone quality is most appropriate to estimate preoperatively fixation strength of instrumental spine fusions. METHODS: VDS-screw fixation strength in 50 human cadaveric vertebral bodies was approximated by means of pullout force assessment. Bone quality was assessed by Dual Energy X-ray Absorptiometry (DEXA), Quantitative Computed Tomography (QCT), MRT and histomorphometry. For each of these techniques, correlation with axial pull out force strength was investigated. RESULTS: Highest correlation was found for cancellous bone density (QCT) (r = 0.72; p < 0.001) and DEXA (r = 0.70; p < 0.001). MRT, cortical bo…
Operator-Related Errors and Pitfalls in Dual Energy X-Ray Absorptiometry: How to Recognize and Avoid Them.
2020
Dual-energy X-ray absorptiometry (DXA) is the most common modality for quantitative measurements of bone mineral density. Nevertheless, errors related to this exam are still very common, and may significantly impact on the final diagnosis and therapy. Operator-related errors may occur during each DXA step and can be related to wrong patient positioning, error in the acquisition process or in the scan analysis. The aim of this review is to provide a practical guide on how to recognize such errors in spine and hip DXA scan and how to avoid them, also presenting some of the most common artifacts encountered in clinical practice.
All that glitters is not gold: A spinal epidural empyema following epidural steroid injection
2020
Background: Therapeutic epidural spinal injections (ESIs) of steroids are one of the most common nonsurgical management modalities employed for alleviating pain due to chronic persistent lumbar spinal disease. However, it is well documented that they have significant risks and complications without any long-term efficacy. ESI may result in epidural empyema which may be difficult to diagnose with delays resulting in significant permanent neurological sequelae. Case Description: A 45-year-old female presented with a lumbar spinal epidural empyema after receiving ESI for low back and right leg pain due to a lumbar disc herniation. Laboratory studies showed elevations of multiple inflammatory …
Mechanical loading influences the lumbar intervertebral disc : A cross‐sectional study in 308 athletes and 71 controls
2021
There is evidence in animal populations that loading and exercise can positively impact the intervertebral disc (IVD). However, there is a paucity of information in humans. We examined the lumbar IVDs in 308 young athletes across six sporting groups (baseball, swimming, basketball, kendo, soccer and running; mean age 19yrs) and 71 non‐athletic controls. IVD status was quantified via the ratio of IVD to vertebral body height (IVD hypertrophy) and ratio of signal intensity in the nucleus to that in the annulus signal (IVD nucleus hydration) on sagittal T2‐weighted MRI. P‐values were adjusted via the false discovery rate method to mitigate false positives. In examining the whole collective, co…
Exercise for the intervertebral disc : a 6-month randomised controlled trial in chronic low back pain
2020
Background context Muscle, bone and tendon respond anabolically to mechanical forces. Whether the intervertebral disc (IVD) can benefit from exercise is unclear. Purpose To examine whether exercise can beneficially affect IVD characteristics. Study design/setting This is a single-blinded 6-month randomised controlled trial (ACTRN12615001270505) in an exercise and physiotherapy clinic. Patient sample Forty patients with chronic non-specific low back pain (NSCLBP) are included in this study. Outcome measures The primary outcome was lumbar IVD T2 time (MRI). Secondary outcomes included IVD diffusion coefficient and IVD expansion with short-duration lying. Methods Twenty patients progressively …
Orientation and exfoliation of clay nanoparticles in the spinning of a nanobiocomposite sample
2016
Polymer nanobiocomposites represent a new group of materials filled with inert nanosized particles that show very interesting properties with respect to the matrix and the same biodegradability of the matrix. In this work we have studied the effect of the elongational flow on the morphology and dynamic-mechanical properties of a new nanobiocomposite made by a matrix of biodegradable PLA and a filler of organomodified montmorillonite.
Intrinsic spin-orbit interaction in diffusive normal wire Josephson weak links: Supercurrent and density of states
2016
We study the effect of the intrinsic (Rashba or Dresselhaus) spin-orbit interaction in superconductor–nanowire–superconductor (SNS) weak links in the presence of a spin-splitting field that can result either from an intrinsic exchange field or the Zeeman effect of an applied field. We solve the full nonlinear Usadel equations numerically [The code used for calculating the results in this paper is available in https://github.com/wompo/Usadel-for-nanowires] and analyze the resulting supercurrent through the weak link and the behavior of the density of states in the center of the wire. We point out how the presence of the spin-orbit interaction gives rise to a long-range spin triplet supercurr…
Pēcoperācijas analgēzijas līmeņa izvērtēšana pēc n. ischiadicus bloka ar multimodālās analgēzijas protokolu apakšstilba lūzuma gadījumā
2018
Neskatoties uz mūsdienu medicīnas attīstību, augsts pēcoperācijas sāpju līmenis vēl aizvien ir aktuāla problēma, īpaši traumatoloģijā. Apakšstilba lūzuma rekonstrukcijas operācijās kā pamata anestēzijas metode tiek lietota spinālā anestēzija (SA). Tiek meklētas papildus iespējas, kuras iekļaut multimodālās analgēzijas shēmā, lai efektīvi kontrolētu sāpes. N. ischiadicus bloks (NIB) varētu būt efektīvs perifēriskās nervu blokādes veids, kas samazinātu pēcoperācijas sāpju līmeni. Mērķis: samazināt pēcoperācijas sāpes pēc apakšstilba lūzumu rekonstrukcijas operācijām, izmantojot NIB. Materiāli un metodes: Prospektīvs, randomizēts pētījums. Pacienti, kuriem tika veikta apakšstilba lūzuma rekons…
Electrocatheter-mediated High-voltage Pulsed Radiofrequency of the Dorsal Root Ganglion in the Treatment of Chronic Lumbosacral Neuropathic Pain
2019
Objectives: Despite the interest in scientific community, there is still poor evidence about pulsed radiofrequency (PRF) efficacy in the treatment of neuropathic pain. In order to determine whether high-voltage PRF and epidural adhesiolysis (PRF-EA) showed better results than epidural adhesiolysis alone (EA), a randomized, double-blind, comparative-effectiveness study was conducted in patients with chronic lumbosacral radiating pain and neuropathic features. Materials and Methods: A total of 41 patients were randomly allocated to 2 groups. Twenty-one patients were randomized to receive 2 cycles of 240 seconds high-voltage PRF followed by the injection of local anesthetics, hyaluronidase, an…
Setting the basis for the study of intermediate conformers of human neuroserpin by Double Electron Electron Resonance
2012
The Double Electron Electron Resonance (DEER) is an innovative technique that allows to measure the distance distribution between two spin labels within a range of 2-8 nm. This technique does not require crystalline samples, thus it is possible to determine the position of two different spin labelled domains of intrinsically flexible macromolecular systems. Our idea is to determinate the structural details of the intermediate conformers of human neuroserpin (hNS) by DEER. hNS is a protein that in the native state is folded in a metastable conformation. In particular conditions, hNS can either adopt a more stable conformation with the reactive centre loop (RCL) inserted into a β-sheet (laten…