Prognostic factors of choroidal melanoma in Slovenia, 1986-2008.

Introduction: Choroidal melanoma is the most common primary malignancy of the eye, which frequently metastasizes. The Cancer Registry of Slovenia reported the incidence of choroid melanoma from 1983 to 2009 as stable, at 7.8 cases/million for men and 7.

Study of translational dynamics in molten polymer by variation of gradient pulse-width of PGSE.

Pulsed gradient spin echo is a method of measuring molecular translation. Changing Δ makes it sensitive to diffusion spectrum. Spin translation effects the buildup of phase structure during the application of gradient pulses as well.

Low-frequency proton NMR relaxometry of a polymer dispersed liquid crystal above TNI.

Using proton NMR relaxometry in the kilohertz frequency range, we study dynamics of 5CB liquid crystal molecules dispersed in the form of spherical microdroplets in a PDLC material. The focus of the study is the spin-lattice relaxation in the rotating frame, T1rho(-1), measured above the nematic-isotropic transition TNI. We show that the relaxation rate T1rho(-1)--when induced by uniform molecular translational diffusion in a spherical cavity--depends on the strength of the rotating magnetic field as T1rho(-1) proportional to omega1(-alpha) where alpha varies between 0.

Suppression of red cell diffusional water permeability by lipophilic solutes.

The inhibitory effect of a series of neutral lipophilic solutes (methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-amylalcohol, n-hexanol, diethylether, nitrobenzene, and pyridine) on the diffusional water permeability (Pd, tot) of bovine erythrocyte membrane at 25 degrees C was studied in comparison to that of p-chloromercuri benzoate (pCMB). Permeability data were obtained by measuring the transmembrane diffusional water exchange time tau(exch) using an 1H-T2 NMR technique. Maximal inhibition by approximately 50% of Pd, tot was produced by 2 mM pCMB which completely blocked the membrane water channels in 20 min, hence suggesting the channel-to-lipid diffusional water permeability ratio of about 1:1.

Ethanol- and acetonitrile-induced inhibition of water diffusional permeability across bovine red blood cell membrane.

The effect of 0-3% (v/v) ethanol and acetonitrile on water diffusional permeability of bovine and chicken red blood cells (RBCs) was studied using a pulse 1H-T2 NMR technique. Transmembrane water diffusional exchange times, tau exch, of 9.2 +/- 0.

Magnetic resonance imaging of retracted and nonretracted blood clots during fibrinolysis in vitro.

Magnetic resonance imaging (MRI) of retracted blood clots embedded in nonretracted clots was used to follow their lysis with urokinase in a plasma milieu in vitro. The two types of clots that were imaged in the same plane differed in signal intensity on T2-weighted spin echo MR images throughout the 20-hour observation period. It was thus possible to delineate the contours of both clot types and measure their relative sizes by digital image processing.

Water proton NMR relaxation mechanisms in lung tissue.

The NMR relaxation times T'2, T2, and T1 were measured in isolated rat lungs as functions of external magnetic field B0, temperature, and lung inflation. The observed linear dependence on B0 of the tissue-induced free induction decay rate (T'2)-1 provides independent confirmation of the air/water interface model of the lung. Furthermore, measurements of the Larmor frequency dependence of T1 are consistent with a spin-lattice relaxation rate of the form 1/T1 = A omega -1/2 + B as expected for the case in which the relaxation arises from water-biopolymer cross-relaxation, which should be proportional to the surface area of the lung.

Non-Brownian water self-diffusion in lung tissue.

Pulsed field gradient NMR measurements of rat lung tissue have shown that the apparent water self-diffusion coefficient is nearly an order of magnitude smaller than that of free water and moreover is not constant but varies as the inverse square root of the diffusion time. The mean square displacement of water molecules is similarly proportional to the square root of the diffusion time. Possible origins of this non-Brownian behavior are discussed.

Proton magnetic relaxation dispersion in human fluoromethaemoglobin solutions.

The solvent proton spin-lattice relaxation time of high spin Fe3+ (S=5/2) human A fluoromethaemoglobin aqueous solutions was measured at 14 Larmor frequencies in the range from 2.2 to 96 MHz. The observed paramagnetic relaxation rates are analysed in terms of the Solomon-Bloembergen theory, with the g-tensor value of 2 based on the consideration of the protein tertiary structure.