Phosphatase and Tensin Homolog Is a Growth Repressor of Both Rhizoid and Gametophore Development in the Moss Physcomitrella patens.

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a lipid phosphatase implicated in cellular proliferation and survival. In animal cells, loss of PTEN leads to increased levels of phosphatidylinositol (3,4,5)-trisphosphate, stimulation of glucose and lipid metabolism, cellular growth, and morphological changes (related to adaptation and survival). Intriguingly, in plants, phosphatidylinositol (3,4,5)-trisphosphate has not been detected, and the enzymes that synthesize it were never reported.

Lead migration from toys by anodic stripping voltammetry using a bismuth film electrode.

Metals may be released from toys via saliva during mouthing, via sweat during dermal contact, or via gastric and intestinal fluids after partial or whole ingestion. In this study, we determined the lead migration from toys bought on the Portuguese market for children below 3 years of age. The lead migration was performed according to the European Committee for Standardization EN 71-3, which proposes a 2-hour migration test that simulates human gastric conditions.

Ofloxacin determination in urine, serum and pharmaceuticals using an automatic flow potentiometric system.

An automatic system was developed to determine ofloxacin in biological fluids and pharmaceutical formulations. Drug detection was carried out by a potentiometric membrane sensor based on [bis(trifluoromethyl)phenyl]borate as molecular-recognition material. The tubular shaped detector system was solidly attached to the manifold, creating a high-throughput stable setup (50 samples per hour) appropriate for routine antibiotic assessment.

Flow amperometric determination of pharmaceuticals with on-line electrode surface renewal.

In this article, a flow system developed for the amperometric determination of a great variety of pharmaceuticals that are known to lead the rapid poisoning of the working electrode surface is described. The referred system was made up of two parallel flow channels that shared the voltammetric detector of tubular configuration, whose movement in the manifold followed the concept of multi-site location of detector. In this way, after each measurement, the conditioning of the working electrode was possible through the passage by its surface of a regeneration solution without implying the alteration of the carrier that flowed in the analytical channel of the manifold.

Sequential determination of salicylic and acetylsalicylic acids by amperometric multisite detection flow injection analysis.

An amperometric multisite detection flow injection analysis (FIA) system was developed for sequential determination of 2 analytes with a single sample injection and single detector. Tubular composite carbon electrodes with an inner diameter similar to that of the FIA manifold tubing were constructed so that measurements could be made without impairing the sample plug hydrodynamic characteristics. The electrochemical behavior of the tubular voltammetric cell in a low-dispersion FIA manifold and the behavior of the FIA system incorporating this type of voltammetric cell intended for multisite detection were evaluated by performing measurements with potassium hexacyanoferrate(II).