Polyoxometallates as effective photocatalysts in water purification from pesticides

Polyoxometallates (POM), i.e., metal oxide clusters of mainly tungsten are effective homogeneous photocatalysts for the mineralization of organic pollutants. POM are, at least, as effective as the well studied TiO2. OH⋅radicals formed by the reaction of the photo-excited polyoxometallates with H2O, appear to play a key role in the process. In this study, the photocatalytic activity of POM have been tested on some diversified pesticides of interest such as lindane, bentazone and fenitrothion to determine the feasibility of decontamination of aqueous solutions from these pollutants. The results show that aqueous solutions containing the above pesticides, upon photolysis in the presence of polyoxotungstates undergo effective degradation to CO2, H2O and the corresponding inorganic anions. The intermediates identified give rise to complicated degradation mechanisms prior to mineralization. The characteristic reactions that take place consist of hydroxylation, H-abstraction, dehalogenation, denitration, desulfurization, breaking of the C-C bond etc

Human chromosome 21 gene expression atlas in the mouse.

Genome-wide expression analyses have a crucial role in functional genomics. High resolution methods, such as RNA in situ hybridization provide an accurate description of the spatiotemporal distribution of transcripts as well as a three-dimensional 'in vivo' gene expression overview(1-5). We set out to analyse systematically the expression patterns of genes from an entire chromosome. We chose human chromosome 21 because of the medical relevance of trisomy 21 (Down's syndrome)(6). Here we show the expression analysis of all identifiable murine orthologues of human chromosome 21 genes (161 out of 178 confirmed human genes) by RNA in situ hybridization on whole mounts and tissue sections, and by polymerase chain reaction with reverse transcription on adult tissues. We observed patterned expression in several tissues including those affected in trisomy 21 phenotypes (that is, central nervous system, heart, gastrointestinal tract, and limbs). Furthermore, statistical analysis suggests the presence of some regions of the chromosome with genes showing either lack of expression or, to a lesser extent, co-expression in either lack of expression or, to a lesser extent, co-expression in specific tissues. This high resolution expression 'atlas' of an entire human chromosome is an important step towards the understanding of gene function and of the pathogenetic mechanisms in Down's syndrome