1,158 research outputs found
Accurate ab initio determination of magnetic interactions and hopping integrals in La2-xSrxCuO4 systems
The nature of magnetic interactions and electron transfer processes in La22xSrxCuO4 systems are
studied, by means of an ab initio embedded cluster model approach, using a difference dedicated
configuration interaction ~DDCI! procedure. For the undoped system, the crucial role played by the
ligand to metal charge transfer ~LMCT! configurations in the magnetic process makes necessary the
use of an enlarged DDCI space, which explicitly takes account of the relaxation of these LMCT
configurations. This procedure allows us to approach the experimental magnetic coupling constant
value. In hole-doped systems, the value obtained for the electron transfer integral, t, is of 0.54–0.57
eV. The extra hole, characterized from the nature and occupation of differential natural orbitals,
has a strong p character ~approximately 50%! and is essentially localized in CuO2 planes. These
results are in agreement with the experimental evidence about these kinds of compounds. Neither
the value of t nor the nature of the extra hole are seriously affected by the optimization of the
orbitals used in the CI expansion. This suggests that a t – J effective Hamiltonian is an adequate
model to study the electronic properties of these system
Immunoexpression of E-cadherin and Vimentin in Normal Oral Mucosa, Oral Epithelial Displasia and Oral Squamous Cell Carcinoma
Indexación: Web of Science; Scopus; Scielo.El objetivo fue evaluar la inmunoexpresión de E-cadherina y Vimentina en mucosa oral normal (MON), displasia epitelial oral (DEO) y carcinoma oral de células escamosas (COCE). Se realizó un estudio descriptivo de una serie de casos analizandolos mediante técnica de inmunohistoquímica contra E-cadherina y Vimentina 16 muestras de MON, 16 de DEO y 19 de COCE. La inmunotinción fue evaluada cualitativamente considerando extensión e intensidad para E-cadherina e intensidad para Vimentina. El análisis de la extensión e intensidad de la inmunotinción de E-cadherina y Vimentina según diagnóstico reveló una asociación estadísticamente significativa (p<0,001). Siendo la expresión de E-cadherina más alta en MON, seguido por DEO y más baja en COCE, inversamente a lo que se observó con Vimentina. El presente estudio reveló la subregulación del marcador molecular E-cadherina junto con la expresión aberrante por parte de células epiteliales del marcador mesenquimal Vimentina en muestras de MON, DEO y COCE.The aim was to evaluate the expression of E-cadherin and Vimentin in oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC), in comparison with normal oral mucosa (NOM) in a descriptive case study using immunohistochemistry. A total of fifty-one (N=51) histological samples were included; as follows: n = 16 (NOM), n = 16 (OED) and n = 19 (OSCC). All samples were analyzed using immunohistochemistry against the expression of E-cadherin and Vimentin. Immunostaining was qualitatively evaluated by extent and intensity of its expression for E-cadherin and intensity for Vimentin. Extension and intensity analysis of E-cadherin and Vimentin immunostaining according to group revealed a statistically significant association (r<0.001). E-cadherin expression was found to be highest in NOM followed by OED and lowest in OSCC, inverse to what was observed with Vimentin. The present study revealed the down regulation of the molecular marker E-cadherin, suggestive of reduction in dysplastic cells on comparison to NOM cells, and aberrant expression of the mesenchymal marker Vimentin by epithelial cells in samples of NOM, OED and OSCC; questioning their value as a prognostic marker.http://ref.scielo.org/pk8s6
Genomic Evolution of Two Acinetobacter baumannii Clinical Strains from ST-2 Clones Isolated in 2000 and 2010 (ST-2_clon_2000 and ST-2_clon_2010)
Acinetobacter baumannii is a successful nosocomial pathogen due to its ability to persist in hospital environments by acquiring
mobile elements such as transposons, plasmids, and phages. In this study, we compared two genomes of A. baumannii clinical
strains isolated in 2000 (ST-2_clon_2000) and 2010 (ST-2_clon_2010) from GenBank project PRJNA308422
Guiding criteria for instrument design at long-pulse neutron sources
6 págs.; 3 figs.; 7th Meeting of the Spanish Neutron Scattering Association (SETN); Open Access funded by Creative Commons Atribution Licence 3.0We introduce and describe general criteria which characterize long-pulse neutron sources, with a view to guiding and facilitating subsequent instrument design and optimization for specific applications. The ensuing analysis shows that a long-pulse neutron source allows for the possibility of a wide range of flexible instrument concepts with variable resolution and dynamic range, tasks which invariably require the implementation of pulse-modulation techniques in the time domain, particularly for high-resolution applications. We also consider in some detail yet-to-be-tapped opportunities in the use of shorter proton pulses, characterised by a duration commensurate with typical moderation times at spallation sources.This work would not have been possible without the support of the computing infrastructure of the i2BASQUE Academic
Network and the support of the ESS-DMSC Computing Centre.Peer Reviewe
Handlebar injury in children: Are we ignoring the signs?
AbstractThe diagnosis of blunt intestinal injury in children is difficult and often delayed. We describe two cases of delayed diagnosis of intestinal injury following handlebar injury with abdominal wall tattooing. We review the literature to try and determine the usefulness of handlebar tattooing characteristics as a clinical sign for underlying small bowel injury in order to reduce delayed treatment. We propose a management algorithm for patients with handlebar tattooing
Genetic differentiation between two geographic subpopulations of Bermeya goat
Ponencia publicada en ITEA, vol.104Este trabajo es un análisis preliminar de la diversidad y grado de diferenciación genética entre las subpoblaciones
Oriental y Occidental de la cabra de raza Bermeya de Asturias. Se han genotipado 27
microsatélites en 122 individuos pertenecientes a las poblaciones de cabra Bermeya Oriental, Bermeya
Occidental, del Guadarrama, Alpine y Saanen. Las poblaciones de raza Bermeya presentaron heterocigosis
esperadas menores de 0,6 y coascendencias moleculares dentro de población de 0,419, reflejando
una alta identidad genética entre individuos. Asimismo, el número medio de alelos por locus, ajustado
por el tamaño muestral, de las poblaciones Bermeya Oriental y Occidental fueron los menores
encontrados (3,8 y 3,9, respectivamente). La mayor coascendencia molecular se encontró entre las
poblaciones Bermeya Oriental-Guadarrama (0,388 ± 0,006), como consecuencia de la introgresión, en
el Oriente asturiano de individuos de tipo Pirenáico. Este parámetro entre las poblaciones de Bermeya
Oriental y Occidental fue de 0,371 ± 0,007. Puede ser necesario establecer estrategias de conservación
diferenciadas para las dos poblaciones geográficas de cabra Bermeya.Two geographic subpopulations (Eastern and Western) of the Asturian Bermeya goat were analysed
using 27 microsatellites. A total of 122 individuals of Bermeya, Guadarrama, Alpine and Saanen goat
breeds were genotyped. The Eastern and Western Bermeya subpopulations had expected
heterozygosity values lower than 0.6 and within-subpopulations molecular coancestry values of 0.419,
thus illustrating a high between individuals genetic identity. The rarefacted average number of alleles
per locus found in both the Eastern and the Western Bermeya subpopulations were the lowest in the
dataset (3.8 and 3.9, respectively). The higher between-populations molecular coancestry values was
found for the pair Eastern Bermeya-Guadarrama (0.388 ± 0.006), thus reflecting the introgression of
the Pyrenean-type goat into Eastern Asturias. This parameter between the two Bermeya
subpopulations was of 0.371 ± 0.007. It could be recommended the implementation of different
conservation strategies for each of the geographic subpopulations of Bermeya goat
Efficient RDF Interchange (ERI) format for RDF data streams
RDF streams are sequences of timestamped RDF statements or graphs, which can be generated by several types of data sources (sensors, social networks, etc.). They may provide data at high volumes and rates, and be consumed by applications that require real-time responses. Hence it is important to publish and interchange them efficiently. In this paper, we exploit a key feature of RDF data streams, which is the regularity of their structure and data values, proposing a compressed, efficient RDF interchange (ERI) format, which can reduce the amount of data transmitted when processing RDF streams. Our experimental evaluation shows that our format produces state-of-the-art streaming compression, remaining efficient in performance
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