4,868 research outputs found
Preditores de fibrilação atrial de novo em unidade de cuidados intensivos não cardíaca
OBJECTIVE:
To assess the predictors of de novo atrial fibrillation in patients in a non-cardiac intensive care unit.
METHODS:
A total of 418 hospitalized patients were analyzed between January and September 2016 in a non-cardiac intensive care unit. Clinical characteristics, interventions, and biochemical markers were recorded during hospitalization. In-hospital mortality and length of hospital stay in the intensive care unit were also evaluated.
RESULTS:
A total of 310 patients were included. The mean age of the patients was 61.0 ± 18.3 years, 49.4% were male, and 23.5% presented de novo atrial fibrillation. The multivariate model identified previous stroke (OR = 10.09; p = 0.016) and elevated levels of pro-B type natriuretic peptide (proBNP, OR = 1.28 for each 1,000pg/mL increment; p = 0.004) as independent predictors of de novo atrial fibrillation. Analysis of the proBNP receiver operating characteristic curve for prediction of de novo atrial fibrillation revealed an area under the curve of 0.816 (p 5,666pg/mL. There were no differences in mortality (p = 0.370), but the lengths of hospital stay (p = 0.002) and stay in the intensive care unit (p = 0.031) were higher in patients with de novo atrial fibrillation.
CONCLUSIONS:
A history of previous stroke and elevated proBNP during hospitalization were independent predictors of de novo atrial fibrillation in the polyvalent intensive care unit. The proBNP is a useful and easy- and quick-access tool in the stratification of atrial fibrillation risk.Objetivo:
Avaliar quais os preditores de fibrilação atrial de novo em doentes de uma unidade de cuidados intensivos não cardíaca.
Métodos:
Foram analisados 418 doentes internados entre janeiro e setembro de 2016 em uma unidade de cuidados intensivos não cardíaca. Registaram-se as características clínicas, as intervenções efetuadas e os marcadores bioquímicos durante a internação. Avaliaram-se ainda a mortalidade hospitalar e o tempo de internação hospitalar e na unidade de cuidados intensivos.
Resultados:
Foram incluídos 310 doentes, com média de idades de 61,0 ± 18,3 anos, 49,4% do sexo masculino, 23,5% com fibrilação atrial de novo. O modelo multivariável identificou acidente vascular cerebral prévio (OR de 10,09; p = 0,016) e valores aumentados de proBNP (OR de 1,28 por cada aumento em 1.000pg/mL; p = 0,004) como preditores independentes de fibrilação atrial de novo. A análise por curva Característica de Operação do Receptor do proBNP para predição de fibrilação atrial de novo revelou área sob a curva de 0,816 (p 5.666pg/mL. Não se verificaram diferenças na mortalidade (p = 0,370), porém a duração da internação hospitalar (p = 0,002) e na unidade de cuidados intensivos (p = 0,031) foi superior nos doentes com fibrilação atrial de novo.
Conclusões:
História de acidente vascular cerebral prévio e proBNP elevado em internação constituíram preditores independentes de fibrilação atrial de novo na unidade de cuidados intensivos polivalente. O proBNP pode constituir ferramenta útil, de fácil e rápido acesso na estratificação do risco de fibrilação atrial.info:eu-repo/semantics/publishedVersio
Finite-momentum Bose-Einstein condensates in shaken 2D square optical lattices
We consider ultracold bosons in a 2D square optical lattice described by the
Bose-Hubbard model. In addition, an external time-dependent sinusoidal force is
applied to the system, which shakes the lattice along one of the diagonals. The
effect of the shaking is to renormalize the nearest-neighbor hopping
coefficients, which can be arbitrarily reduced, can vanish, or can even change
sign, depending on the shaking parameter. It is therefore necessary to account
for higher-order hopping terms, which are renormalized differently by the
shaking, and introduce anisotropy into the problem. We show that the
competition between these different hopping terms leads to finite-momentum
condensates, with a momentum that may be tuned via the strength of the shaking.
We calculate the boundaries between the Mott-insulator and the different
superfluid phases, and present the time-of-flight images expected to be
observed experimentally. Our results open up new possibilities for the
realization of bosonic analogs of the FFLO phase describing inhomogeneous
superconductivity.Comment: 7 pages, 7 figure
Tidal damping of the mutual inclination in hierachical systems
Hierarchical two-planet systems, in which the inner body's semi-major axis is
between 0.1 and 0.5 AU, usually present high eccentricity values, at least for
one of the orbits. As a result of the formation process, one may expect that
planetary systems with high eccentricities also have high mutual inclinations.
However, here we show that tidal effects combined with gravitational
interactions damp the initial mutual inclination to modest values in timescales
that are shorter than the age of the system. This effect is not a direct
consequence of tides on the orbits, but it results from a secular forcing of
the inner planet's flattening. We then conclude that these hierarchical
planetary systems are unlikely to present very high mutual inclinations, at
least as long as the orbits remain outside the Lidov-Kozai libration areas. The
present study can also be extended to systems of binary stars and to
planet-satellite systems.Comment: 16 pages, 13 figure
Current-driven and field-driven domain walls at nonzero temperature
We present a model for the dynamics of current- and field-driven domain-wall
lines at nonzero temperature. We compute thermally-averaged drift velocities
from the Fokker-Planck equation that describes the nonzero-temperature dynamics
of the domain wall. As special limits of this general description, we describe
rigid domain walls as well as vortex domain walls. In these limits, we
determine also depinning times of the domain wall from an extrinsic pinning
potential. We compare our theory with previous theoretical and experimental
work
Vortex-lattice pinning in two-component Bose-Einstein condensates
We investigate the vortex-lattice structure for single- and two-component
Bose-Einstein condensates in the presence of an optical lattice, which acts as
a pinning potential for the vortices. The problem is considered in the
mean-field quantum-Hall regime, which is reached when the rotation frequency
of the condensate in a radially symmetric trap approaches the (radial)
trapping frequency and the interactions between the atoms are weak. We
determine the vortex-lattice phase diagram as a function of optical-lattice
strength and geometry. In the limit of strong pinning the vortices are always
pinned at the maxima of the optical-lattice potential, similar to the
slow-rotation case. At intermediate pinning strength, however, due to the
competition between interactions and pinning energy, a structure arises for the
two-component case where the vortices are pinned on lines of minimal potential
Pokrovsky-Talapov Model at finite temperature: a renormalization-group analysis
We calculate the finite-temperature shift of the critical wavevector
of the Pokrovsky-Talapov model using a renormalization-group analysis.
Separating the Hamiltonian into a part that is renormalized and one that is
not, we obtain the flow equations for the stiffness and an arbitrary potential.
We then specialize to the case of a cosine potential, and compare our results
to well-known results for the sine-Gordon model, to which our model reduces in
the limit of vanishing driving wavevector Q=0. Our results may be applied to
describe the commensurate-incommensurate phase transition in several physical
systems and allow for a more realistic comparison with experiments, which are
always carried out at a finite temperature
Topological Defects and the Spin Glass Phase of Cuprates
We propose that the spin glass phase of cuprates is due to the proliferation
of topological defects of a spiral distortion of the antiferromagnet order. Our
theory explains straightforwardly the simultaneous existence of short range
incommensurate magnetic correlations and complete a-b symmetry breaking in this
phase. We show via a renormalization group calculation that the collinear
O(3)/O(2) symmetry is unstable towards the formation of local non-collinear
correlations. A critical disorder strength is identified beyond which
topological defects proliferate already at zero temperature.Comment: 7 pages, 2 figures. Final version with some changes and one replaced
figur
CYP3A5 genetic polymorphism in HIV-patients
Poster presented at the From Basic Sciences to Clinical Research - First International Congress of CiiEM. Egas Moniz, Caparica, Portugal, 27-28 November 2015"A number of relevant polymorphisms are known for affecting the most common prescribed ARVs (antiretroviral), inducing drug toxicity, risk of virologic failure and may explain the interpatient variability for drug absorption pathways. CYP3A5 is an isoform of Cytochromes P4503A family, estimated to participate in the metabolism of 40 to 60% of all clinically administered drugs, namely atazanavir (1). The aim of this study was to characterize the CYP3A5 polymorphisms of HIV infected patients, from Santa Maria Hospital, Lisbon, Portugal.
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