1,128 research outputs found
Biologia Molecular na Medicina Veterinária: conceitos e avanços
A descoberta da estrutura do DNA por Watson & Crick (1953) deu inicio a uma nova era na biologia molecular. As ferramentas em biologia molecular têm sido utilizadas para pesquisa em muitos campos da biologia e da medicina. Em medicina veterinária, a biologia molecular tem sido aplicada ao diagnostico das doenças parasitárias e infecciosas, desenvolvimento de vacinas e terapêutica, terapia gênica, genética da resistência a doenças, genotipagem de patógenos, etc. Este artigo foi escrito com ênfase aos conceitos e aplicação da biologia molecular na medicina veterinária.  
Impact of meteorological variables on water quality parameters of a reservoir and ecological filtration system
Recently, special attention has been given to low-cost technologies for water treatment, with the aim of serving remote communities and thus enabling everyone to have access to drinking water and basic sanitation. In that context, the ecological filter is an alternative for treating water for human consumption. Some studies show that climate change and meteorological parameters can influence the water quality of water bodies and the water supply system. However, most of the papers deal with model projections and therefore do not show real situations. The aim of this study was to determine the impact of meteorological variables (e.g. atmospheric pressure, evaporation, wind speed, radiation, precipitation) on the physico-chemical and biological parameters (e.g. turbidity, apparent colour, pH, total coliforms, Escherichia coli) of Lobo reservoir water treated by 22 ecological filters during a period of 4 months. Statistically significant correlations were found between the water from the Lobo reservoir and the weather variables, and between the water quality parameters of the 22 ecological filters and the average weather variables. The results from the statistical analysis indicate that climatic variations may influence treatment performance
Left ventricular false aneurysm characterized by cardiovascular magnetic resonance and late enhancement technique
Left ventricular pseudoaneurysm is a rare
complication of myocardial infarction.
Differentiation between true and false aneurysms,
although difficult, is crucial, because of the
different treatment options they entail.
We present a rare case of a giant pseudoaneurysm
of the left ventricle related with a previous
myocardial infarction. The present case highlights
the pivotal role of magnetic resonance imaging
for differential diagnosis between these entities
Left ventricular false aneurysm characterized by cardiovascular magnetic resonance and late enhancement technique
Left ventricular pseudoaneurysm is a rare
complication of myocardial infarction.
Differentiation between true and false aneurysms,
although difficult, is crucial, because of the
different treatment options they entail.
We present a rare case of a giant pseudoaneurysm
of the left ventricle related with a previous
myocardial infarction. The present case highlights
the pivotal role of magnetic resonance imaging
for differential diagnosis between these entities
Structure characterization and mechanism of growth of PbTe nanocrystals embedded in a silicate glass
A nanocomposite consisting of PbTe nanocrystals embedded in a silicate glass was studied by small-angle x-ray scattering during the early stage of isothermal annealing at 793 K. A theoretical function based on a model of spherical PbTe nanocrystals surrounded by a Pb and Te depleted shell fits well to all experimental curves. The time dependences of the nanocrystal radius and size of the depleted shell agree with the prediction of the theory of nucleation and growth by the classical mechanism of atomic diffusion.892
Decoding negative affect personality trait from patterns of brain activation to threat stimuli
INTRODUCTION: Pattern recognition analysis (PRA) applied to functional magnetic resonance imaging (fMRI) has been used to decode cognitive processes and identify possible biomarkers for mental illness. In the present study, we investigated whether the positive affect (PA) or negative affect (NA) personality traits could be decoded from patterns of brain activation in response to a human threat using a healthy sample. METHODS: fMRI data from 34 volunteers (15 women) were acquired during a simple motor task while the volunteers viewed a set of threat stimuli that were directed either toward them or away from them and matched neutral pictures. For each participant, contrast images from a General Linear Model (GLM) between the threat versus neutral stimuli defined the spatial patterns used as input to the regression model. We applied a multiple kernel learning (MKL) regression combining information from different brain regions hierarchically in a whole brain model to decode the NA and PA from patterns of brain activation in response to threat stimuli. RESULTS: The MKL model was able to decode NA but not PA from the contrast images between threat stimuli directed away versus neutral with a significance above chance. The correlation and the mean squared error (MSE) between predicted and actual NA were 0.52 (p-value=0.01) and 24.43 (p-value=0.01), respectively. The MKL pattern regression model identified a network with 37 regions that contributed to the predictions. Some of the regions were related to perception (e.g., occipital and temporal regions) while others were related to emotional evaluation (e.g., caudate and prefrontal regions). CONCLUSION: These results suggest that there was an interaction between the individuals' NA and the brain response to the threat stimuli directed away, which enabled the MKL model to decode NA from the brain patterns. To our knowledge, this is the first evidence that PRA can be used to decode a personality trait from patterns of brain activation during emotional contexts
QUANTUM SIZE EFFECTS ON CDTEXS1-X SEMICONDUCTOR-DOPED GLASS
We present experimental evidences of quantum confinement in borosilicate glasses with a new microcrystallite CdTexS1-x semiconductor. The microcrystallite sizes are controlled by the heat-treatment time and temperature. Transmission electron microscopy measurements show the microcrystallites average diameters near 55 angstrom for the sample treated for the longest time. We observe a red shift from 570 to 640 nm in the absorption and photoluminescence spectra as the size increases. These shifts agree with the expected quantum-confined energies, varying from 0.80 to 0.60 eV. The absorption spectra also show a second feature which can be assigned to the second quantum-confined transition.59212715271
Size effects on the phonon spectra of quantum dots in CdTe-doped glasses
We studied the confinement effects on the phonon Spectra of CdTe quantum dots by means of resonant Raman scattering measurements. The spectra show clearly longitudinal optical phonons, surface phonons and some of their overtone combinations. We show that the scattering due to surface phonons increases as the quantum dot size decreases. The results are obtained by tuning the laser excitation energy to resonance for quantum dots of different sizes inside the broad size distribution in CdTe-doped glasses. (C) 1996 American Institute of Physics.69335735
Plasmacytoma of the lumbar spine
Solitary bone plasmacytoma is a plasma cell
disorder characterized by the formation of a single
tumor in the bone. Most commonly, the tumor
develops in the spine, and is progressively less
frequent in the pelvis, ribs, upper extremities, skull,
femur and sternum. Symptoms are mainly local.
In most cases, multiple myeloma ensues,
conferring it a poor prognosis.
The authors describe the case of a 53-year-old
male patient who presented with persistent low
back pain without apparent cause until a
radiography of the lumbar spine was performed.
It revealed a lytic lesion, which was proven to be a
plasmacytoma after a computed tomography
guided biopsy
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