6,313 research outputs found

    Angiogenesis-dependent and independent phases of intimal hyperplasia.

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    BACKGROUND: Neointimal vascular smooth muscle cell (VSMC) proliferation is a primary cause of occlusive vascular disease, including atherosclerosis, restenosis after percutaneous interventions, and bypass graft stenosis. Angiogenesis is implicated in the progression of early atheromatous lesions in animal models, but its role in neointimal VSMC proliferation is undefined. Because percutaneous coronary interventions result in induction of periadventitial angiogenesis, we analyzed the role of this process in neointima formation. METHODS AND RESULTS: Local injury to the arterial wall in 2 different animal models induced periadventitial angiogenesis and neointima formation. Application of angiogenesis stimulators vascular endothelial growth factor (VEGF-A165) or a proline/arginine-rich peptide (PR39) to the adventitia of the injured artery induced a marked increase in neointimal thickening beyond that seen with injury alone in both in vivo models. Inhibition of either VEGF (with soluble VEGF receptor 1 [sFlt1]) or fibroblast growth factor (FGF) (with a dominant=negative form of FGF receptor 1 [FGF-R1DN]), respectively, signaling reduced adventitial thickening induced by VEGF and PR39 to the level seen with mechanical arterial injury alone. However, neither inhibitor was effective in preventing neointimal thickening after mechanical injury when administered in the absence of angiogenic growth factor. CONCLUSIONS: Our findings indicate that adventitial angiogenesis stimulates intimal thickening but does not initiate it

    Hardware Accelerated Fast FDTD of Time Dependent Maxwell’s Equations on Xilinx RF SoC

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    Electromagnetics, which govern the fields of wireless communications, radar, and remote sensing, are fully described using four first-order PDEs known as Maxwell’s Equations. The finite-difference time-domain (FDTD) algorithm invented by Yee in 1966 operates on a discrete space-time staggered grid-pair for the electric and magnetic fields, and solutions are obtained via leapfrog update equations. The field of computational electromagnetics makes extensive use of the FDTD algorithm for modeling involving various types of antennas, microwave filters, circuits, aerospace vehicles, and wireless systems. For accurate and dispersion-less solution, the discretization of the spatial and temporal variables require a high degree of over-sampling that is much higher than what is demanded by the Nyquist Sampling Theorem, in order for the discrete domain update equations to represent the behavior of a continuous linear PDE system. The highly-oversampled nature of FDTD results in high computational complexity and therefore long execution times on high-performance computing systems. Hardware acceleration is a technique to accelerate the computation of FDTD using application-specific integrated digital processor arrays that are custom designed for implementing FDTD without using any software at all. The hard-wired parallel computation allows very good acceleration compared to state-of-art computing solutions based on high-performance compute servers, GPU realizations, and cloud computing techniques. The talk reports on a hardware accelerator that supports real-time operation on a Xilinx RF SoC device. Comparison with GPUs are provided (interim results show better than x100)

    Phase diagram for non-axisymmetric plasma balls

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    Plasma balls and rings emerge as fluid holographic duals of black holes and black rings in the hydrodynamic/gravity correspondence for the Scherk-Schwarz AdS system. Recently, plasma balls spinning above a critical rotation were found to be unstable against m-lobed perturbations. In the phase diagram of stationary solutions the threshold of the instability signals a bifurcation to a new phase of non-axisymmetric configurations. We find explicitly this family of solutions and represent them in the phase diagram. We discuss the implications of our results for the gravitational system. Rotating non-axisymmetric black holes necessarily radiate gravitational waves. We thus emphasize that it would be important, albeit possibly out of present reach, to have a better understanding of the hydrodynamic description of gravitational waves and of the gravitational interaction between two bodies. We also argue that it might well be that a non-axisymmetric m-lobed instability is also present in Myers-Perry black holes for rotations below the recently found ultraspinning instability.Comment: 1+22 pages, 3 figures. v2: minor corrections and improvements, matches published versio

    Weak Field Black Hole Formation in Asymptotically AdS Spacetimes

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    We use the AdS/CFT correspondence to study the thermalization of a strongly coupled conformal field theory that is forced out of its vacuum by a source that couples to a marginal operator. The source is taken to be of small amplitude and finite duration, but is otherwise an arbitrary function of time. When the field theory lives on Rd−1,1R^{d-1,1}, the source sets up a translationally invariant wave in the dual gravitational description. This wave propagates radially inwards in AdSd+1AdS_{d+1} space and collapses to form a black brane. Outside its horizon the bulk spacetime for this collapse process may systematically be constructed in an expansion in the amplitude of the source function, and takes the Vaidya form at leading order in the source amplitude. This solution is dual to a remarkably rapid and intriguingly scale dependent thermalization process in the field theory. When the field theory lives on a sphere the resultant wave either slowly scatters into a thermal gas (dual to a glueball type phase in the boundary theory) or rapidly collapses into a black hole (dual to a plasma type phase in the field theory) depending on the time scale and amplitude of the source function. The transition between these two behaviors is sharp and can be tuned to the Choptuik scaling solution in Rd,1R^{d,1}.Comment: 50 pages + appendices, 6 figures, v2: Minor revisions, references adde

    Genetics of bushy growth habit and its implications in chickpea improvement

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    Chickpea (Cicer arietinum L.) plant is generally erect, semi-erect, spreading, semi-prostrate or prostrate (mainly wild annual Cicer species) in growth habit depending on the angle of branches arises from the vertical axis. Spontaneous mutations are the source of genetic variability and have resulted into dwarf erect compact type plants with high number of branches arising from base, commonly called as “bushy mutants” in chickpea [1-3]. In a study [4], it was reported that mean yield of the lines with bushy growth habit, across all environments, was higher than that of the erect habit lines..

    Severity of post-operative pain after instrumentation of root canals by XP-Endo and SAF full sequences compared to manual instrumentation: a randomized clinical trial

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    This investigation aimed to examine the post-operative pain experienced following single-visit root canal treatment using the XP-endo shaper sequence (XPS), full-sequence self-adjusting file (SAF), and manual K-files (HKF). A randomized equivalence parallel design, double-blinded clinical study was conducted on 120 patients with symptomatic irreversible pulpitis, with or without clinical signs of apical periodontitis. Only teeth with fully formed roots and no periapical lesions were incorporated in the study. Patients were apportioned to one of three groups (n = 40) randomly: Group 1—XPS, Group 2—SAF, and Group 3—HKF. Pre- and post-instrumentation pain was rated utilizing Visual Analog Scale (VAS) with a spectrum of 0–100 mm. The descriptive statistics and one-way ANOVA with 95% confidence intervals were used for statistical analysis. The mean VAS scores before instrumentation were consistent in all three groups. At 6, 24, 48, and 72 h, patients with root canals instrumented by SAF had the lowest post-instrumentation mean VAS score, followed by XPS. For all time intervals, the patients in the HKF group had the highest VAS score. The full-sequence SAF instrumentation resulted in less post-operative pain than the XP-endo plus protocol, while manual instrumentation with K-files resulted in the highest post-operative pain
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