4,447 research outputs found
A Maxwell-vector p-wave holographic superconductor in a particular background AdS black hole metric
We study the p-wave holographic superconductor for AdS black holes with
planar event horizon topology for a particular Lovelock gravity, in which the
action is characterized by a self-interacting scalar field nonminimally coupled
to the gravity theory which is labeled by an integer . As the Lovelock
theory of gravity is the most general metric theory of gravity based on the
fundamental assumptions of general relativity, it is a desirable theory to
describe the higher dimensional spacetime geometry. The present work is devoted
to studying the properties of the p-wave holographic superconductor by
including a Maxwell field which nonminimally couples to a complex vector field
in a higher dimensional background metric. In the probe limit, we find that the
critical temperature decreases with the increase of the index of the
background black hole metric, which shows that a larger makes it harder for
the condensation to form. We also observe that the index affects the
conductivity and the gap frequency of the holographic superconductors.Comment: 14 pages, 6 figure
Poly[[(methanol)(μ4-2,4,5,6-tetraÂfluoroÂbenzene-1,3-dicarboxylÂato)copper(II)] methanol monosolvate]
In the title compound, {[Cu(C8F4O4)(CH3OH)]·CH3OH}n, two CuII atoms are bridged by four carboxylÂate groups, forming the well known paddle-wheel secondary building unit (SBU) with axial methanol ligands. In each ligand, the dihedral angles between the benzene ring and the two carboxylÂate groups are 80.43 (17) and 62.5 (4)°. Within each SBU, the four carboxylÂate groups come from four symmetry-equivalent tetraÂfluoroÂisophthalate ligands. Each tetraÂfluoroÂisophthalate group connects two SBUs, forming a layered structure . In the crystal, O—H⋯O hydrogen bonds involving the free and ligated methanol molÂecules link the molÂecules into a three-dimensional supraÂmolecular network
Partial network coding: Theory and application for continuous sensor data collection
Abstract — Wireless sensor networks have been widely used for surveillance in harsh environments. In many such applications, the environmental data are continuously sensed, and data collection by a server is only performed occasionally. Hence, the sensor nodes have to temporarily store the data, and provide easy and on-hand access for the most updated data when the server approaches. Given the expensive server-to-sensor communications, the large amount of sensors and the limited storage space at each tiny sensor, continuous data collection becomes a challenging problem. In this paper, we present partial network coding (PNC) as a generic tool for the above applications. PNC generalizes the existing network coding (NC) paradigm, an elegant solution for ubiquitous data distribution and collection. Yet, PNC enables efficient storage replacement for continuous data, which is a major deficiency of the conventional NC. We prove that the performance of PNC is quite close to NC, except for a sublinear overhead on storage and communications. We then address a set of practical concerns toward PNC-based continuous data collection in sensor networks. Its feasibility and superiority are further demonstrated through simulation results. I
Inhibition of proliferation, migration and invasion of human non-small cell lung cancer cell line A549 by phlomisoside F from Phlomis younghusbandii Mukerjee
Purpose: To determine the effect of phlomisoside F (PMF) on the proliferation, migration and invasion of human non-small cell lung cancer cell line A549 and explore the possible mechanisms.Methods: The anti-proliferative effect of PMF on A549 cells was determined by CCK-8. Subsequently, migration and invasion were evaluated by Transwell and Transwell with matrigel assays, respectively. Furthermore, cell cycle and apoptosis were assessed by flow cytometry, while the mechanisms of action were determined by Western blotting.Results: PMF exhibited significant anti-proliferative effect on A549 cells in concentration-dependent and time-dependent manners, with half maximal inhibitory concentration (IC50) of 54.51 μM. Treatment with PMF (10, 20 and 40 μM) for 48 h resulted in significantly decreased migration and invasion in A549 cells. In addition, PMF at concentrations of 25, 50 and 75 μM induced cell cycle arrest in G0/G1phase and enhanced cell apoptosis in A549 cells. Furthermore, caspase-3, caspase-9 and Bax protein expressions were up-regulated while Bacl-2 and COX-2 protein expressions were significantly downregulated at 10, 20 and 40 μM concentrations of PMF.Conclusion: PMF suppresses A549 cell growth, migration and invasion. The mechanism may be related to the induction of mitochondria-mediated apoptosis pathway via regulation of caspase-3, caspase-9, Bcl-2 and Bax expressions, and inhibition of PGE2 synthesis by reducing COX-2 expression.Keywords: Phlomisoside F, Lung cancer, Cell mobility, Apoptosis, PGE2, COX-2 expression, Caspase, Cell cycle arres
The Navier-Stokes Equations with the Kinematic and Vorticity Boundary Conditions on Non-Flat Boundaries
We study the initial-boundary value problem of the Navier-Stokes equations
for incompressible fluids in a general domain in with compact and smooth
boundary, subject to the kinematic and vorticity boundary conditions on the
non-flat boundary. We observe that, under the nonhomogeneous boundary
conditions, the pressure can be still recovered by solving the Neumann
problem for the Poisson equation. Then we establish the well-posedness of the
unsteady Stokes equations and employ the solution to reduce our
initial-boundary value problem into an initial-boundary value problem with
absolute boundary conditions. Based on this, we first establish the
well-posedness for an appropriate local linearized problem with the absolute
boundary conditions and the initial condition (without the incompressibility
condition), which establishes a velocity mapping. Then we develop
\emph{apriori} estimates for the velocity mapping, especially involving the
Sobolev norm for the time-derivative of the mapping to deal with the
complicated boundary conditions, which leads to the existence of the fixed
point of the mapping and the existence of solutions to our initial-boundary
value problem. Finally, we establish that, when the viscosity coefficient tends
zero, the strong solutions of the initial-boundary value problem in with nonhomogeneous vorticity boundary condition converges in to the
corresponding Euler equations satisfying the kinematic condition.Comment: 31 page
Cooperative Coding and Caching for Streaming Data in Multihop Wireless Networks
This paper studies the distributed caching managements for the current flourish of the streaming applications inmultihop wirelessnetworks. Many caching managements to date use randomized network coding approach, which provides an elegant solution forubiquitous data accesses in such systems. However, the encoding, essentially a combination operation, makes the coded datadifficult to be changed. In particular, to accommodate new data, the system may have to first decode all the combined datasegments, remove some unimportant ones, and then reencode the data segments again. This procedure is clearly expensivefor continuously evolving data storage. As such, we introduce a novel Cooperative Coding and Caching (C3) scheme, whichallows decoding-free data removal through a triangle-like codeword organization. Its decoding performance is very close to theconventional network coding with only a sublinear overhead. Our scheme offers a promising solution to the caching managementfor streaming data
Time to tackle clonorchiasis in China
Recent publication of the global epidemiology of clonorchiasis and its relationship with cholangiocarcinoma in the journal of Infectious Diseases of Poverty has stressed the importance of Clonorchis sinensis infection. To further demonstrate its threat on public health, especially in China, comparisons between clonorchiasis and hepatitis B are made in terms of epidemiology, clinical symptoms and carcinogenicity, disability, as well as changing trends. Furthermore, major problems and prioritized researches are argued, from basic biology to intervention. Imbalance between the majority of infected population and the minority of researches in China urges for more work from Chinese scientists and international cooperation
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