Lama Naji

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Pulsed field gradient (PFG) nuclear magnetic resonance (NMR) was used to investigate the self-diffusion behaviour of polymers in cartilage. Polyethylene glycol and dextran with different molecular weights and in different concentrations were used as model compounds to mimic the diffusion behaviour of metabolites of cartilage. The polymer self-diffusion(More)
Rheumatic diseases are accompanied by a progressive destruction of the cartilage layer of the joints. Despite the frequency of the disease, degradation mechanisms are not yet understood and methods for early diagnosis are not available. Although some information on pathogenesis could be obtained from the analysis of degradation products of cartilage(More)
Rheumatic diseases are accompanied by a progressive destruction of the cartilage layers of the joints. Although the number of patients suffering from rheumatic diseases is steadily increasing, degradation mechanisms of cartilage are not yet understood, and methods for early diagnosis are not available. Although some information on pathogenesis could be(More)
In this study, the pulsed field gradient (PFG) nuclear magnetic resonance (NMR) technique was used for the investigation of (1) concentration and compression effects on cation self-diffusion, and (2) restricted diffusion of cations in cartilage. Since physiologically relevant cations like Na+ are difficult to investigate owing to their very short relaxation(More)
Although the gel forming ability of certain polysaccharides in the presence of ions is a well-known phenomenon, detailed physicochemical mechanisms of such processes are still unknown. In this investigation high resolution 13C NMR as well as 1H pulsed field gradient (PFG) NMR were used to investigate the mobility of dextran in the sol and in the gel state.(More)
Segregation structures of granular mixtures in rotating drums represent classical examples of pattern formation in granular material. We investigate the coarsening of axial segregation patterns of slurries in a long horizontally rotating cylinder. The dynamics and the three-dimensional geometry of the segregation structures are analyzed with optical methods(More)
We have investigated the molecular motions of polysaccharides of bovine nasal and pig articular cartilage by measuring the 13C NMR relaxation times (T1 and T2). Both types of cartilage differ significantly towards their collagen/glycosaminoglycan ratio, leading to different NMR spectra. As chondroitin sulfate is the main constituent of cartilage, aqueous(More)
—In software radio systems, a digital IIR filter offers good roll-off and transition bandwidth characteristics using a low amount of arithmetic components, thus simplifying hardware implementation. However, IIR filter structures are very sensitive to finite precision compared to FIR filter structures. In order to design a high quality, low component count,(More)
Since cartilage contains neither blood nor lymph vessels, diffusion is the most important transport process for the supply of cartilage with nutrients and for the removal of metabolic waste products. Therefore, diffusion measurements are of high interest in cartilage research. Different techniques of diffusion measurements exist. Here we describe methods(More)