Distribution of mosquitoes in the South East of Argentina and first report on the analysis based on 18S rDNA and COI sequences

Although Mar del Plata is the most important city on the Atlantic coast of Argentina, mosquitoes inhabiting such area are almost uncharacterized. To increase our knowledge in their distribution, we sampled specimens of natural populations. After the morphological identification based on taxonomic keys, sequences of DNA from small ribosomal subunit (18S rDNA) and cytochrome c oxidase I (COI) genes were obtained from native species and the phylogenetic analysis of these sequences were done. Fourteen species from the genera Uranotaenia, Culex, Ochlerotatus and Psorophora were found and identified. Our 18S rDNA and COI-based analysis indicates the relationships among groups at the supra-species level in concordance with mosquito taxonomy. The introduction and spread of vectors and diseases carried by them are not known in Mar del Plata, but some of the species found in this study were reported as pathogen vectors

Molecular dynamics simulation of the aqueous solvation shell of cellulose and xanthate ester derivatives

Gonzalo Riadi, Fernando González-Nilo. Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Casilla 721, Talca, Chile.MD simulations of a pentasaccharide having D-glucopyranoside residues connected by (14)- glycosidic linkages, as a model of cellulose solvated in water, were carried out comparing the solvation of the hydroxyl group at C2 of the central ring of the pentamer and that of a single glucopyranose ring. MD simulations of 10 nsec were carried under NPT and periodic boundary conditions at 298 K and 1 atm. Explicit solvent (TIP3) and the force field CHARMM27 (modified for xanthate ester derivatives) were used in the molecular dynamics simulations. RDF calculations with respect to O2 of the central ring of the pentamer showed a well structured first solvation shell followed by secondary shells. When comparing the simulations of the pentamer to a single glucopyranose ring, it was observed that the solvation of O2 was lower for one repetitive unit, indicating that the pentamer had a stronger H-bond structure of water around O2 due to the cooperative effect of the neighboring residues. When the O2 of the central ring of the pentamer was substituted by a p-nitrobenzylxanthate moiety (pentXNB) there was a strong decrease in the hydration of the substituted O2 but the carbon and the sulfur of the thiocarbonyl group were clearly hydrated compared to the sulfur bridge. The global minimum energy conformation showed the p-nitrobenzyl group folded over the neighboring glucose ring. However, the simulations showed that the XNB group oscillates over the pentamer in periods of ca. 3000 psec

PET, TOMOGRAFIA POR EMISION DE POSITRONES: PRESENTACION DE UN CASO CLINICO

Se presenta un caso clínico de una paciente estudiada por nódulo pulmonar solitario con Tomografía por Emisión de Positrones utilizando Flúor18-deoxiglucosa. Con el estudio metabólico quedó en evidencia la malignidad del nódulo y la aparición de dos nuevos focos sugerentes de diseminación, no demostrados por otras técnicas diagnósticasA patient with a solitary pulmonary nodule is presented. She was studied with PET using F-18 FDG. The metabolic images demonstrated increased uptake in the nodule and 2 additional areas suggestive of extension, not seen in anatomic diagnostic procedures. These findings were compatible with a malignant tumour with metastasi

Intramolecular Amino-thiolysis Cyclization of Graphene Oxide Modified with Sulfur Dioxide: XPS and Solid-State NMR Studies

Graphite microparticles were oxidized to graphene oxide (MPGO) by Hummers’ method followed by thermal exfoliation (C/O ratio 1.53). Graphene oxide was modified with SO2 (mMPGO) at 600 °C and by subsequent treatment at 200 °C having a sulfur content of 10.9% (C/O ratio 16.94) and manganese content 9.39 μmol·g–1. The XPS spectrum of MPGO showed the presence of carbonyl and epoxide groups. The reactivity of mMPGO toward alkyl thiol and alkyl amine showed the same selectivity as other carbons and suggested that oxidation did not modify deeply the edging structure of graphite. Therefore, the tetradehydrogenated-benzo[α]anthracene (TBA) reactive site model is valid. From XPS and solid-state NMR, amino-thiolysis occurred via cyclization. On the basis of the joint analysis of solid-state 1H and 13C NMR spectra of mMPGOs treated with mono- and difunctionalized alkanes, a preferred conformation of the alicyclic moiety of aminothiol over the graphene matrix occurred via binding to mMPGO at both amine and thiol ends. It was found that paramagnetic manganese ions in mMPGO can lead to cross-polarization inefficiency in the 13C CPMAS detection of alkyl chains bound to mMPGO, while ring currents from graphene aromatic layers can shift alkyl 1H NMR signals to lower frequencies by up to 4 ppm