Introduction Dynamic C NMR spectroscopy combined with C label administration has been used to study brain metabolism non-invasively. N-acetyl aspartate (NAA) metabolism has been considered to be slow [1-3] and to have a similar turnover time as glycogen [3]. Most studies employed direct C detection to measure C label in NAA, with an additional external reference to calculate the isotopic enrich...

BACKGROUND AND PURPOSE Theoretically, proton ((1)H) MR spectroscopy at a higher field strength has the advantages of higher signal-to-noise ratio and improved spectral resolution. We therefore compared the ability of single-voxel (1)H MR spectroscopy at 1.5 and 3 T to diagnostically discriminate among cognitively normal elderly subjects, patients with mild cognitive impairment (MCI), and patien...

N-acetyl-aspartyl-glutamate (NAAG) and its hydrolysis product N-acetyl-L-aspartate (NAA) are among the most important brain metabolites. NAA is a marker of neuron integrity and viability, while NAAG modulates glutamate release and may have a role in neuroprotection and synaptic plasticity. Investigating on a quantitative basis the role of these metabolites in brain metabolism in vivo by magneti...

objective(s) the purpose of the present study was to use the solid dispersion (sd) technique to improve the dissolution rates of indomethacin (imc). materials and methods imc solid dispersions in pvp k30 and isomalt (galen iq 990) were prepared using the solvent evaporation technique and a hot melt method in weight ratios of 2, 10 and 30% (imc:pvp). solid dispersions and physical mixtures were ...

In this work, we report synthesis and characterization of copper nanoparticles in polymer matrix by wet-chemical reduction method using ascorbic acid as reducing agent, copper (II) sulfate as metal precursor and polyvinylpyrrolidone k-30 (PVP K-30) as surfactant agent. The reaction was carried out in a high-speed stirring mixture at room temperature under nitrogen atmosphere. Characterization o...

To use the "apparent diffusion coefficient" (Dapp) as a quantitative imaging parameter, well-suited test fluids are essential. In this study, the previously proposed aqueous solutions of polyvinylpyrrolidone (PVP) were examined and temperature calibrations were obtained. For example, at a temperature of 20°C, Dapp ranged from 1.594 (95% CI: 1.593, 1.595) μm2/ms to 0.3326 (95% CI: 0. 3304, 0.334...