54,407 research outputs found

    Unusual association of ST-T abnormalities, myocarditis and cardiomyopathy with H1N1 influenza in pregnancy: two case reports and review of the literature.

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    Introduction Myocarditis is rarely reported as an extra-pulmonary manifestation of influenza while pregnancy is a rare cause of cardiomyopathy. Pregnancy was identified as a major risk factor for increased mortality and morbidity due to H1N1 influenza in the pandemic of 2009 to 2010. However, to the best of our knowledge there are no previous reports in the literature linking H1N1 with myocarditis in pregnancy. Case presentation We report the cases of two pregnant Caucasian women (aged 29 and 30), with no pre-existing illness, presenting with respiratory manifestations of H1N1 influenza virus infection in their third trimester. Both women developed evidence of myocarditis. One woman developed acute respiratory distress syndrome, almost reaching the point of requiring extra-corporeal membrane oxygenation, and subsequently developed persistent cardiomyopathy; the other recovered without any long-term consequence. Conclusions While it is not possible to ascertain retrospectively if myocarditis was caused by either infection with H1N1 virus or as a result of pregnancy (in the absence of endomyocardial biopsies), the significant association with myocardial involvement in both women demonstrates the increased risk of exposure to H1N1 influenza virus in pregnant women. This highlights the need for health care providers to increase awareness amongst caregivers to target this 'at risk' group aggressively with vaccination and prompt treatment

    Instability of three dimensional conformally dressed black hole

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    The three dimensional black hole solution of Einstein equations with negative cosmological constant coupled to a conformal scalar field is proved to be unstable against linear circularly symmetric perturbations.Comment: 5 pages, REVTe

    The signature of the magnetorotational instability in the Reynolds and Maxwell stress tensors in accretion discs

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    The magnetorotational instability is thought to be responsible for the generation of magnetohydrodynamic turbulence that leads to enhanced outward angular momentum transport in accretion discs. Here, we present the first formal analytical proof showing that, during the exponential growth of the instability, the mean (averaged over the disc scale-height) Reynolds stress is always positive, the mean Maxwell stress is always negative, and hence the mean total stress is positive and leads to a net outward flux of angular momentum. More importantly, we show that the ratio of the Maxwell to the Reynolds stresses during the late times of the exponential growth of the instability is determined only by the local shear and does not depend on the initial spectrum of perturbations or the strength of the seed magnetic. Even though we derived these properties of the stress tensors for the exponential growth of the instability in incompressible flows, numerical simulations of shearing boxes show that this characteristic is qualitatively preserved under more general conditions, even during the saturated turbulent state generated by the instability.Comment: 9 pages, 4 figures. Minor revisions. Accepted for publication in MNRA

    A Solvable Model of Two-Dimensional Dilaton-Gravity Coupled to a Massless Scalar Field

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    We present a solvable model of two-dimensional dilaton-gravity coupled to a massless scalar field. We locally integrate the field equations and briefly discuss the properties of the solutions. For a particular choice of the coupling between the dilaton and the scalar field the model can be interpreted as the two-dimensional effective theory of 2+1 cylindrical gravity minimally coupled to a massless scalar field.Comment: 6 pages, RevTeX, to be published in Phys. Rev.

    The 2D analogue of the Reissner-Nordstrom solution

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    A two-dimensional (2D) dilaton gravity model, whose static solutions have the same features of the Reissner-Nordstrom solutions, is obtained from the dimensional reduction of a four-dimensional (4D) string effective action invariant under S-duality transformations. The black hole solutions of the 2D model and their relationship with those of the 4D theory are discussed.Comment: 5 pages, Plain-Tex, no figure

    AN ANKLE SPRAIN RECOGNITION SYSTEM FOR IDENTIFYING ANKLE SPRAIN MOTION FROM OTHER NORMAL MOTION USING MOTION SENSOR

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    The purpose of this study was to develop an ankle sprain recognition system which identifies ankle sprain motions from other normal motions. Six healthy male subjects performed a total of 600 simulated ankle sprain motions and normal sports motions. Eight motion sensors were attached to cover the whole foot segment to monitor the linear velocity and angular accelerations of the segment. The data obtained from the motion sensor at the medial calcaneus selected to train up the Support Vector Machine (SVM). The trained SVM model was then verified by another 600 trials from other six healthy male subjects. Among the 300 sprain trials, 291 (97.0%) of them were identified correctly. However, there was still a 14.3% false alarm which normal trials being identified as sprain trails. In general, a good accuracy of 91.3% was achieved

    Iterative solution of perturbation equations

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    Iterative solution of perturbation equation

    The emergence of cognitive COVID

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    Geometrical properties of the trans-spherical solutions in higher dimensions

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    We investigate the geometrical properties of static vacuum pp-brane solutions of Einstein gravity in D=n+p+3D=n+p+3 dimensions, which have spherical symmetry of Sn+1S^{n+1} orthogonal to the pp-directions and are invariant under the translation along them. % The solutions are characterized by mass density and pp tension densities. % The causal structure of the higher dimensional solutions is essentially the same as that of the five dimensional ones. Namely, a naked singularity appears for most solutions except for the Schwarzschild black pp-brane and the Kaluza-Klein bubble. % We show that some important geometric properties such as the area of Sn+1S^{n+1} and the total spatial volume are characterized only by the three parameters such as the mass density, the sum of tension densities and the sum of tension density squares rather than individual tension densities. These geometric properties are analyzed in detail in this parameter space and are compared with those of 5-dimensional case.Comment: 14 pages, 2 figures, Title change

    Effects of reconstituted collagen matrix on fates of mouse embryonic stem cells before and after induction for chondrogenic differentiation

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    Embryonic stem (ES) cells are pluripotent cells with great potential in regenerative medicine. However, controlling their differentiation toward homogeneous lineages is challenging. In this study, we aim to investigate the effects of reconstituted 3D collagen matrix on the fates of mouse ES (mES) cells before and after induction for chondrogenic differentiation. Specifically, mES cells were encapsulated and cultured in 3D collagen microspheres and exposed to induction signals at different time points. Growth characteristics and differentiation status of mES cells were then evaluated. Collagen microspheres provided a suitable microenvironment supporting mES cell growth and maintaining their undifferentiated status for certain period of time. At later time points, the proportion of undifferentiated mES cells gradually decreased, accompanied by increasing proportions of mesenchymal progenitor cells. This suggests the inductive role of collagen matrix in differentiating mES cells toward mesenchymal lineages. Moreover, a lower initial collagen monomer concentration facilitated the differentiation of mES cells into chondrogenic lineages, while induction at a later time point associated with a more advanced stage of chondrogenic differentiation. This indicates that both the initial collagen concentration and the time to induce differentiation significantly affected the fates of mES cells. This study contributes to future development of ES cell-based therapies. © Copyright 2009, Mary Ann Liebert, Inc.published_or_final_versionThe 7th Annual Meeting of the International Society for Stem Cell Research (ISSCR), Barcelona, Spain, 8-11 July 2009. In Tissue Engineering. Part A, 2009, v. 15 n. 10, p. 3071-308
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