98 research outputs found
DISTRIBUTION OF QT DURATION ACCORDING TO AMBULATORY ECG MONITORING DATA IN PATIENTS WITH HYPERTENSION DEPENDING ON CLINICAL MANIFESTATIONS
The study was carried out to identify the distribution of QTc during ECG AM depending on clinical features of EH in 82 patients. As classified shortened was considered QTс 320 ms and 440 ms. Average, maximum and minimum QTc are registered in every patient during ECG AM. The results confirm low probability of short QTc and demonstrate presence of prolonged QTc in every patient during ECG AM. The largest duration of maximal QTc have adulthood male patients with obesity III st., with low and high circadian index, with II stage and mild EH, with for the first time diagnosed EH and with EH lasting more than 10 years, with mild cardiovascular risk, with diffuse cardiosclerosis, with I and II FC and I and IIA st of HF
Symmetry of the remanent state flux distribution in superconducting thin strips: Probing the critical state
The critical-state in a thin strip of YBaCuO is studied by magneto-optical
imaging. The distribution of magnetic flux density is shown to have a specific
symmetry in the remanent state after a large applied field. The symmetry was
predicted [PRL 82, 2947 (1999)] for any Jc(B), and is therefore suggested as a
simple tool to verify the applicability of the critical-state model. At large
temperatures we find deviations from this symmetry, which demonstrates
departure from the critical-state behavior. The observed deviations can be
attributed to an explicit coordinate dependence of since both a surface
barrier, and flux creep would break the symmetry in a different way.Comment: 5 pages including 5 eps figures, submitted to PR
Evolution of the electronic structure with size in II-VI semiconductor nanocrystals
In order to provide a quantitatively accurate description of the band gap
variation with sizes in various II-VI semiconductor nanocrystals, we make use
of the recently reported tight-binding parametrization of the corresponding
bulk systems. Using the same tight-binding scheme and parameters, we calculate
the electronic structure of II-VI nanocrystals in real space with sizes ranging
between 5 and 80 {\AA} in diameter. A comparison with available experimental
results from the literature shows an excellent agreement over the entire range
of sizes.Comment: 17 pages, 4 figures, accepted in Phys. Rev.
Importin α7 Is Essential for Zygotic Genome Activation and Early Mouse Development
Importin α is involved in the nuclear import of proteins. It also contributes to spindle assembly and nuclear membrane formation, however, the underlying mechanisms are poorly understood. Here, we studied the function of importin α7 by gene targeting in mice and show that it is essential for early embryonic development. Embryos lacking importin α7 display a reduced ability for the first cleavage and arrest completely at the two-cell stage. We show that the zygotic genome activation is severely disturbed in these embryos. Our findings indicate that importin α7 is a new member of the small group of maternal effect genes
From a nonlinear string to a weakly interacting Bose gas
We investigate a real scalar field whose dynamics is governed by a nonlinear
wave equation. We show that classical description can be applied to a quantum
system of many interacting bosons provided that some quantum ingredients are
included. An universal action has to be introduced in order to define particle
number. The value of this action should be equal to the Planck constant. This
constrain can be imposed by removing high frequency modes from the dynamics by
introducing a cut-off. We show that the position of the cut-off has to be
carefully adjusted. Finally, we show the proper choice of the cut-off ensures
that all low frequency eigenenmodes which are taken into account are
macroscopically occupied.Comment: 7 pages, 4 figure
Flux-Induced Vortex in Mesoscopic Superconducting Loops
We predict the existence of a quantum vortex for an unusual situation. We
study the order parameter in doubly connected superconducting samples embedded
in a uniform magnetic field. For samples with perfect cylindrical symmetry, the
order parameter has been known for long and no vortices are present in the
linear regime. However, if the sample is not symmetric, there exist ranges of
the field for which the order parameter vanishes along a line, parallel to the
field. In many respects, the behavior of this line is qualitatively different
from that of the vortices encountered in type II superconductivity. For samples
with mirror symmetry, this flux-induced vortex appears at the thin side for
small fluxes and at the opposite side for large fluxes. We propose direct and
indirect experimental methods which could test our predictions.Comment: 6 pages, Latex, 4 figs., uses RevTex, extended to situations far from
cylindrical symmetr
The Flux-Line Lattice in Superconductors
Magnetic flux can penetrate a type-II superconductor in form of Abrikosov
vortices. These tend to arrange in a triangular flux-line lattice (FLL) which
is more or less perturbed by material inhomogeneities that pin the flux lines,
and in high- supercon- ductors (HTSC's) also by thermal fluctuations. Many
properties of the FLL are well described by the phenomenological
Ginzburg-Landau theory or by the electromagnetic London theory, which treats
the vortex core as a singularity. In Nb alloys and HTSC's the FLL is very soft
mainly because of the large magnetic penetration depth: The shear modulus of
the FLL is thus small and the tilt modulus is dispersive and becomes very small
for short distortion wavelength. This softness of the FLL is enhanced further
by the pronounced anisotropy and layered structure of HTSC's, which strongly
increases the penetration depth for currents along the c-axis of these uniaxial
crystals and may even cause a decoupling of two-dimensional vortex lattices in
the Cu-O layers. Thermal fluctuations and softening may melt the FLL and cause
thermally activated depinning of the flux lines or of the 2D pancake vortices
in the layers. Various phase transitions are predicted for the FLL in layered
HTSC's. The linear and nonlinear magnetic response of HTSC's gives rise to
interesting effects which strongly depend on the geometry of the experiment.Comment: Review paper for Rep.Prog.Phys., 124 narrow pages. The 30 figures do
not exist as postscript file
Структурные, электрические и люминесцентные характеристики ультрафиолетовых светодиодов, выращенных методом хлорид–гидридной эпитаксии
Electrical and luminescent properties of near−UV light emitting diode structures (LEDs) prepared by hydride vapor phase epitaxy (HVPE) were studied. Variations in photoluminescence and electroluminescence efficiency observed for LEDs grown under nominally similar conditions could be attributed to the difference in the structural quality (dislocation density, density of dislocations agglomerates) of the GaN active layers, to the difference in strain relaxation achieved by growth of AlGaN/AlGaN superlattice and to the presence of current leakage channels in current confining AlGaN layers of the double heterostructure.Изучены электрические и люминесцентные характеристики светодиодных структур (СД), излучающих в ближней ультрафиолетовой (УФ) области и выращенных методом хлорид−гидридной эпитаксии. Обнаружены различия в характеристиках УФ СД, выращенных в номинально одинаковых условиях, которые приписывают различиям в структурном совершенстве (плотности дислокаций и дислокационных агломератов) в активных слоях GaN, разнице в степени релаксации напряжений, достигаемой с помощью сверхрешеток AlGaN/AlGaN, а также существованию каналов токовых утечек в слоях AlGaN, ограничивающих заряд в двойной гетероструктуре.
The onset of psoriasis during the treatment of inflammatory bowel diseases with infliximab: should biological therapy be suspended?
Dilemas éticos en el trabajo de campo: temas olvidados en la investigación cualitativa en salud en Iberoamérica
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