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Visar resultat 1 - 5 av 73 avhandlingar som matchar ovanstående sökkriterier.
1. Nuclear Magnetic Resonance for Diffusion Imaging Development and evaluation of spin-echo-based pulse sequences for in vivo studies of water self-diffusion
Sammanfattning : The interest in diffusion imaging with nuclear magnetic resonance techniques has increased during the last few years. The main reason is the possibility of early diagnosis of acute ischaemic stroke, at a time when conventional MR techniques and computerised tomography fail. LÄS MER
2. Developing novel diffusion MRI methods for comprehensive analysis of restricted and anisotropic self-diffusion system
Sammanfattning : Diffusion MRI is a non-invasive imaging technique used to study the microstructural properties of biological tissues by observing the self-diffusion of water molecules. Traditional diffusion MRI methods, based on the pulsed gradient spin-echo sequence, employ magnetic field gradients to encode information about translational motion. LÄS MER
3. NMR diffusion studies on lyotropic liquid crystalline systems
Sammanfattning : The pulsed field gradient fourier transform nuclear magnetic resonance (PFG-FTNMR) method to measure translational diffusion coefficients in multicomponent systems has been applied to amphiphilic molecules forming liquid crystalline phases.By analyzing the concentration dependence of the diffusion coefficients of water and amphiphile in a micellar system of N,N-dimethyldodecy lamine oxide (DDAO) in water it was possible to conclude that the micelles formed were polydisperse in size and shape. LÄS MER
4. Diffusion MRI of Small Ischemic Brain Lesions: Technical aspects, clinical experiences and diagnostic criteria
Sammanfattning : Purpose: To compare the visualization of small ischemic brain lesions using diffusion using diffusion-weighted (DW) MRI and conventional imaging, with special regard to diagnostic efficiency. Imaging features of lesions of different ages, diagnostic limitations and technical principles were also investigated. LÄS MER
5. Superdiffusive Spin Transport and Ultrafast Magnetization Dynamics : Femtosecond spin transport as the route to ultrafast spintronics
Sammanfattning : The debate over the origin of the ultrafast demagnetization has been intensively active for the past 16 years. Several microscopic mechanisms have been proposed but none has managed so far to provide direct and incontrovertible evidences of their validity. LÄS MER