The structure of polycaprolactone-clay nanocomposites investigated by 1H NMR relaxometry.

Nanocomposites based on polycaprolactone (PCL), containing concentrations of 1, 3 and 5 wt% of sodium montmorillonite (NT-25) and organo-modified montmorillonite clay, with three different salts (Viscogel B7, Viscogel S4 and Viscogel B8), were prepared employing the solution intercalation method using chloroform. The PCL nanocomposites were characterized by relaxometry, through determination of the hydrogen spin-lattice relaxation times using low-field nuclear magnetic resonance (NMR). Conventional X-ray diffraction (XDR) was also used to measure the basal space of the nanoclay.

Low dosage of 131iodine effects on chromosomes.

The aim of this study was to evaluate the effect on human lymphocyte chromosomes of the (131)I dosage used in scintigraphy on thyroid patients. Until now, there has been as absence of conclusive reports on the effects produced by such dosage. Samples were obtained from 21 patients, and the blood was collected in two occasions: Twenty-four hours prior (control) and after administration of the radionuclide (test).