1,105 research outputs found
Dysembryoplastic neuroepithelial tumors
Rev Neurol. 2000 Mar 1-15;30(5):436-41.
[Dysembryoplastic neuroepithelial tumors]
[Article in Spanish]
Reis JL, Vasconcelos C, Rangel R, Xavier J, Barroso C, Melo-Pires M, Carvalho E.
Servicio de NeurocirugĂa, Hospital Geral Santo AntĂłnio, Porto, Portugal. [email protected]
Abstract
INTRODUCTION: The dysembryoplastic neuroepithelial tumors tend to occur in young patients, with partial complex partial seizures which is refractory to medical treatment. These are stable lesions, with defined histological features, specially with clinical data corroboration.
CLINICAL CASES: The clinical, imagiological, operative, and histopathological data of six patients with proved dysembryoplastic neuroepithelial tumors were reviewed. All patients had seizures with age at onset ranged from 7 to 27 years. Five lesions were located in the temporal lobe and one in the parietal lobe. Common features included cortical to subcortical location, low density in CT-scan, very low signal intensity on T1-weighted images and high signal on T2-weighted images. Calcification occurred in two lesions, and three showed contrast enhancement. Complete resection of the tumor was performed in three cases, and subtotal resection in other three cases. Pathological features included oligodendroglial-like cells, glioneural component, and few cases showed dysplastic cortical disorganization. The postoperative period of follow-up ranged from 2 to 18 months. Four patients were seizure free, two of which had subtotal resection of the lesion. The remaining two patients maintained seizures.
CONCLUSIONS: The clinical, imagiological and histopathological data of the six cases presented are generally compatible with those of the reports reviewed by the authors. The imagiological features are nonspecific. Surgical treatment permits histological diagnosis and epilepsy control.
PMID: 10775970 [PubMed - indexed for MEDLIN
Square to stripe transition and superlattice patterns in vertically oscillated granular layers
We investigated the physical mechanism for the pattern transition from square
lattice to stripes, which appears in vertically oscillating granular layers. We
present a continuum model to show that the transition depends on the
competition between inertial force and local saturation of transport. By
introducing multiple free-flight times, this model further enables us to
analyze the formation of superlattices as well as hexagonal lattice
Effect of replacing wheat bran with spineless cactus plus urea in sugarcane-based diets for sheep
In times of drought, the availability of feed is reduced, and the use of concentrate ingredients, such as wheat bran, becomes costly for animal production. Thus, the use of spineless cactus emerges as a potential solution to the shortage of feed and water during prolonged drought periods. The objective of this study was to evaluate the effects of replacing wheat bran with spineless cactus plus urea (0%, 25%, 50%, 75%, and 100%) in sugarcane-based diets for sheep on nutrient intake, feeding behaviour, nitrogen balance and microbial protein synthesis. Five male Santa Ines sheep with average initial bodyweight of 34.0 ± 3.6 kg were used in a 5 à 5 Latin square. The maximum intakes of dry matter (DM) (1414 g/day), organic matter (OM) (1281 g/day), crude protein (CP) (204 g/day), neutral detergent fibre corrected for ash and protein (NDFap) (425 g/day), and total digestible nutrients (TDN) (890 g/day) were estimated with replacement levels of 80.2%, 75.3%, 88.6%, 50.5%, and 79.3% respectively. Feeding behaviour was not altered by replacing wheat bran with spineless cactus plus urea. Nitrogen retention increased by 0.10 g/day, while plasmatic urea nitrogen increased by 0.20 mg/day for every 1% level of replacement. The maximum production of microbial nitrogen (15.9 g/day) and microbial protein synthesis (99.4 g/day) were estimated with replacement levels of 45.8 and 45.7%, respectively. It is concluded that up to 80% wheat bran could be replaced with spineless cactus plus urea in sugarcane-based diets for sheep.Keywords: Alternative feed, drought, feeding behaviour, intake, microbial protei
Hartree-Fock-Bogoliubov theory versus local-density approximation for superfluid trapped fermionic atoms
We investigate a gas of superfluid fermionic atoms trapped in two hyperfine
states by a spherical harmonic potential. We propose a new regularization
method to remove the ultraviolet divergence in the Hartree-Fock-Bogoliubov
equations caused by the use of a zero-range atom-atom interaction. Compared
with a method used in the literature, our method is simpler and has improved
convergence properties. Then we compare Hartree-Fock-Bogoliubov calculations
with the semiclassical local-density approximation. We observe that for systems
containing a small number of atoms shell effects, which cannot be reproduced by
the semiclassical calculation, are very important. For systems with a large
number of atoms at zero temperature the two calculations are in quite good
agreement, which, however, is deteriorated at non-zero temperature, especially
near the critical temperature. In this case the different behavior can be
explained within the Ginzburg-Landau theory.Comment: 12 pages, 8 figures, revtex; v2: references and clarifying remarks
adde
Orange emission in Pr3+-doped fluoroindate glasses
We synthesize and study the properties of praseodymium doped fluoroindate glasses. Glass compositions with praseodymium molar concentrations up to 5% were obtained with good optical quality. Thermal, optical, and luminescence properties are investigated. JuddâOfelt analysis is used to determine radiative lifetime and emission cross-section of the orange transition originating from the 3P0 level. We find that these glasses are good candidates for the realization of blue diode laser pumped orange lasers for quantum information processing applications
IncidĂȘncia E Mortalidade Por Aids Em Crianças E Adolescentes: Desafios Na RegiĂŁo Sul Do Brasil
The objective of this study is to describe the time trend of coefficients of incidence and mortality associated with AIDS in children and adolescents. An ecological time trend study was conducted among individuals under 14 living in the regional context of high incidence of AIDS â Porto Alegre and the State of Rio Grande do Sul â from 1996 to 2012. For this purpose, a segmented regression model was adjusted for age categories and place of residence. AIDS morbidity and mortality indicators in Porto Alegre are still higher than those registered in the State, the southern region and other areas of the country. In Porto Alegre, 59.1% of cases (371/628) occurred in children under four years of age, the incidence showed peaks in the period and the mortality dropped from 9 to 2 per 100,000. A significant decreasing in annual percentage change in mortality was observed especially in children under 1 year of age in Porto Alegre. This drop may be related to prevention and treatment of pregnant women. The challenge is to identify possible fragilities of the STD/AIDS Program and its vulnerable points in order to make specific interventions and investments with a greater impact potential. © 2016, Associacao Brasileira de Pos - Graduacao em Saude Coletiva. All rights reserved.21123889389
RQM description of the charge form factor of the pion and its asymptotic behavior
The pion charge and scalar form factors, and , are first
calculated in different forms of relativistic quantum mechanics. This is done
using the solution of a mass operator that contains both confinement and
one-gluon-exchange interactions. Results of calculations, based on a one-body
current, are compared to experiment for the first one. As it could be expected,
those point-form, and instant and front-form ones in a parallel momentum
configuration fail to reproduce experiment. The other results corresponding to
a perpendicular momentum configuration (instant form in the Breit frame and
front form with ) do much better. The comparison of charge and scalar
form factors shows that the spin-1/2 nature of the constituents plays an
important role. Taking into account that only the last set of results
represents a reasonable basis for improving the description of the charge form
factor, this one is then discussed with regard to the asymptotic QCD-power-law
behavior . The contribution of two-body currents in achieving the right
power law is considered while the scalar form factor, , is shown to
have the right power-law behavior in any case. The low- behavior of the
charge form factor and the pion-decay constant are also discussed.}Comment: 30 pages, 10 figure
Potential of elephant grass genotypes silages as exclusive roughage on tissue composition and meat quality of lambs: a preliminary study
ABSTRACT This study aimed to evaluate the effects of diets containing elephant grass genotypes silages as exclusive roughage on leg tissue composition, and physicochemical characteristics of meat of lambs. Twenty-four crossbred male lambs with an average initial body weight of 20.29±2.66kg were distributed in a complete randomized design with three treatments and eight replicates. The treatments consisted of three silages of elephant grass genotypes (IRI-381, Elephant B or Mott), without additives or wilting, as the only roughage. The diets did not affect (P>0.05) the dry matter (898.70±60.10 g/day), crude protein (128.93±6.91g/day), total digestible nutrients (690.20±91.82g/day) intakes, body weight at slaughter (24.83±2.79kg), and carcass yields (P>0.05). The tissue composition of the leg did not differ significantly between silages of elephant grass genotypes (P>0.05). No difference (P>0.05) for the physicochemical characteristics of meat from lambs fed diets tested was observed. Therefore, our results indicate that diets containing 50% elephant grass genotypes silages (IRI-381, Elephant B or Mott), harvested at 60 days of growth, have potential for use in lambs feeding
Stripes, Pseudogaps, and Van Hove Nesting in the Three-band tJ Model
Slave boson calculations have been carried out in the three-band tJ model for
the high-T_c cuprates, with the inclusion of coupling to oxygen breathing mode
phonons. Phonon-induced Van Hove nesting leads to a phase separation between a
hole-doped domain and a (magnetic) domain near half filling, with long-range
Coulomb forces limiting the separation to a nanoscopic scale. Strong
correlation effects pin the Fermi level close to, but not precisely at the Van
Hove singularity (VHS), which can enhance the tendency to phase separation. The
resulting dispersions have been calculated, both in the uniform phases and in
the phase separated regime. In the latter case, distinctly different
dispersions are found for large, random domains and for regular (static)
striped arrays, and a hypothetical form is presented for dynamic striped
arrays. The doping dependence of the latter is found to provide an excellent
description of photoemission and thermodynamic experiments on pseudogap
formation in underdoped cuprates. In particular, the multiplicity of observed
gaps is explained as a combination of flux phase plus charge density wave (CDW)
gaps along with a superconducting gap. The largest gap is associated with VHS
nesting. The apparent smooth evolution of this gap with doping masks a
crossover from CDW-like effects near optimal doping to magnetic effects (flux
phase) near half filling. A crossover from large Fermi surface to hole pockets
with increased underdoping is found. In the weakly overdoped regime, the CDW
undergoes a quantum phase transition (), which could be obscured
by phase separation.Comment: 15 pages, Latex, 18 PS figures Corrects a sign error: major changes,
esp. in Sect. 3, Figs 1-4,6 replace
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