Delocalized states in damaged DNA

Recent studies suggest that base pairing is an efficient electronic delocalization mechanism. However, defects may break down such effect. In the present work we show how a simple model of defects suppresses the delocalization, which survives only for low defect concentrations.45946

Confined Placental Mosaicism in Chorionic Vilus Sampling - Case Report

Objectives: Chorionic Vilus Sampling (CVS) has several advantages over amniocentesis: it may be performed at an earlier gestational age, the results are quicker to obtain and there’s a lower miscarriage risk – 1%. However, the higher prevalence of discrepant fetal and vilus sampling material’s karyotype findings is a disadvantage of this technique – 0.5%. This is caused, amongst other causes, by placental mosaicism which consists of two genetically different cell lines. There are three types of placental mosaicism according to the abnormal cell line location: Type I – in the cytotrophoblast; Type II – in the vilus’ stroma; Type III – in both the above locations. Material and Methods: We present a case report about a 36-year-old pregnant woman going through our Department’s 1st trimester combined screening program; a CVS was performed, which showed Confined Placental Mosaicism (CPM). Results and Conclusion: Although the pregnant woman was in the low-risk group for aneuploidy, the patient wanted the cytogenetic study to be performed in order to reduce maternal anxiety. CVS was performed at the gestational age of 12 weeks + 5 days and the karyotype was 47XY+2/46XY. For the correct interpretation of this data an amniocentesis was performed at the gestational age of 15 weeks + 6 days, which showed a 46XY karyotype. We therefore conclude that the cytogenetic analysis of the CVS was the result of a CPM. A careful follow-up including fetal echocardiogram and seriated ultrasonographic monitoring was used to safely exclude malformations and fetal growth restriction. We verified no occurences throughout pregnancy, delivery and perinatal period. CVS practice was recently implemented in our country and has many advantages over amniocentesis. Besides the fact that an earlier gestational age usually means less affective bonding to the fetus and therefore makes medical termination of pregnancy somewhat less difficult, one should consider specific situations like the one reported in which CPM may be diagnosed. This condition is associated with increased risk of fetal growth restriction, so the clinician should be aware of the need for a more careful follow-up, since perinatal complications, which should be anticipated and treated, can be expected in 16-21% of these cases

On a family of topological invariants similar to homotopy groups

The intimacy relation between smooth loops, which is a strong homotopy relation, is generalized to smooth maps defined on the n-cube, leading to a family of groups similar to the classical homotopy groups. The formal resemblance between the two families of groups is explored. Special attention is devoted to the role of these groups as topological invariants for manifolds and as tools for describing geometrical structures defined on manifolds such as bundles and connections

Fluvial transport patterns of dissolved trace metals to the Ria of Cedeira

5 páginas.-- Interdisciplinary Water Congress CINA 2014, Vigo, 2-6 June 2014Samples of water were withdrawn monthly close to the Das Mestas River mouth, out of the tidal influence, from October 2011 to September 2012 (covering a hydrological year). After filtration through 0.45 policarbonate membrane, nine trace metals were analyzed (Al, Co, Cu, Cr, Fe, Mo, Ni, Pb and V) in the dissolved phase. All procedures were made following trace-metal-clean techniques. Three groups of metals were distinguished: Al, Co, Ni, Cu and Pb correlated with the SPM and the DOC indicating they are related with soil leaching; Iron is related with Chl-a so its behavior depends on the biologic activity; lithological influence on Cr, Mo and V patterns was observed.This study was supported by CTM2011-28792-C02 project, Land-sea exchange of trace metals and its importance for marine phytoplankton in an upwelling coast (MITOFE), financed by Spanish MINECOPeer reviewe

Ethanol chemisorption on core-shell Pt-nanoparticles: an ab-initio study

By means of ab-initio calculations, we have investigated the chemisorption paroperties of ethanol onto segregating binary nanoalloys. We select nanostructures with icosahedral shape of 55 atoms with a Pt outermost layer over a M core with M=Ag,Pd,Ni. With respect to nanofilms with equivalent composition, there is an increse of the ethanol binding energy. This is not merely due to observed shortening of the Pt-O distance but depends on the nanoparticle distortion after ethanol adsorption. This geometrical distortion within the nanoparticle can be interpreted as a radial breathing, which is sensitive to the adsortion site, identified by the O-anchor point and the relative positions of the ethyl group. More interestingly, being core-dependent -larger in Pd@Pt and smaller in Ni@Pt-, it relates to an effective electron transfer from ethanol and the M-core towards the Pt-shell. On the view of this new analysis, Pd@Pt nanoalloys show the most promissing features for ethanol oxidation