Gregor Gomišček

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In previous papers relative signal intensity increase was used as a quantitative assessment parameter for contrast uptake in contrast-enhanced MRI. However, relative signal intensity increase does not only reflect contrast uptake but depends also on tissue parameters (native T1 relaxation time) and sequence parameters (repetition time and flip angle); thus,(More)
Giant phospholipid vesicles obtained by the method of electroformation were observed by the phase contrast microscope. Most of these vesicles contain a protrusion which shortens in a slow shape transformation process until it is absorbed into the main vesicle body. We are concerned with the last stages of this shape transformation process, where the(More)
The purpose of the present study was to evaluate the influence of very low ambient illumination and complete darkness on the postural sway of young and elderly adults. Eighteen healthy young participants aged 23.8 ± 1.5 years and 26 community-dwelling elderly aged 69.8 ± 5.6 years were studied. Each participant performed four tests while standing on a force(More)
Rotation of giant "point attached" phospholipid (POPC) vesicles in a shear flow was studied. The dependence of the angular velocity on the flow gradient was measured and the experimental results were compared to the predictions of a theoretical model. A good linear correlation between the angular velocity of the vesicle and the flow gradient, as predicted,(More)
The technique of functional magnetic resonance imaging (FMRI) allows the measurement of functional cerebral blood flow changes occurring with specific tasks. However, the spatial relationship between neuronal activity and functional cerebral blood flow changes is not known yet. This study compares the centre of neuronal activation (measured by(More)
The effects of the polyene pore-forming agent nystatin were investigated on individual giant unilamellar phospholipid vesicles (GUVs), made of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), in different methanol-water solutions using phase-contrast optical microscopy. Three characteristic effects were detected in three different nystatin(More)
The influences of ergosterol and cholesterol on the activity of the nystatin were investigated experimentally in a POPC model membrane as well as theoretically. The behavior of giant unilamellar vesicles (GUVs) under osmotic stress due to the formation of transmembrane pores was observed on single vesicles at different nystatin concentrations using(More)
Differences in MRI-measured contrast enhancement have been used for tissue characterization, particularly for the characterization of mammary tumours. T1 weighted spoiled gradient echo sequences have usually been acquired for this purpose and relative signal intensity increase (Srel) has been determined to quantify contrast uptake. The field strength(More)
The shape transformations of red blood cells stuck in capillary narrowings with radii close to the critical radius where the maximum deformations occur are analyzed. The membrane skeleton deformations are studied within the effective network model and the continuum elastic model, whereas the area-difference elasticity model is applied to describe the(More)
Magnetic resonance angiography (MRA) was compared with conventional angiography in 14 patients following extra-intracranial arterial anastomosis. In 13 patients the bypass was shown by MRA and confirmed by conventional angiography. In five of these, the anastomosed vessels, in particular the superficial temporal artery, was of the same calibre or smaller(More)