Metabolic profiling of organic acids in urine samples of Cri Du Chat syndrome individuals by gas chromatography-mass spectrometry.

Cri Du Chat (CDC) syndrome is a rare genetic condition caused by the deletion of genetic material on the small arm (the p arm) of chromosome 5. A high-pitched cry that sounds like that of a cat, dysmorphic characteristics, and cytogenetic methods are often used for diagnosing the syndrome. In this study, we applied GC-MS analysis for determining organic acids in urine from 17 control volunteers without CDC syndrome, and from 16 individuals with the CDC syndrome in order to determine the profile of organic acids and biochemical pathways alterations resulting from this genetic condition.

Evaluation of the interactions between chitosan and humics in media for the controlled release of nitrogen fertilizer.

The aim of this study was to evaluate the interactions of peat, humic acids, and humin with urea dispersed in chitosan, in systems intended for the controlled release of urea. Spheres of chitosan with humic material and urea intentionally added to the media were prepared and characterized by means of elemental analysis (CHN), electron paramagnetic resonance (EPR), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The spheres possessed functional groups related to humic substances that interacted with the chitosan, and the presence of urea in the media was also confirmed after it has been added.