82,139 research outputs found
Identification of stromal cells in spleen which support myelopoiesis
Stromal cells in spleen organize tissue into red pulp, white pulp and marginal zone, and also interact with hematopoietic cells to regulate immune responses. This study has used phenotypic information of a previously described spleen stromal cell line called 5G3, which supports restricted hematopoiesis in vitro, to identify an equivalent stromal cell subset in vivo and to test its capacity to support hematopoiesis. Using stromal cell fractionation, phenotypic analysis, as well as cell growth and hematopoietic support assays, the Sca-1+gp38+Thy1.2+CD29+CD51+ fraction of spleen stroma has been identified as an equivalent stromal subset resembling the 5G3 cell counterpart. While heterogeneity may still exist within that subset, it has been shown to have superior hematopoietic support capacity compared with the 5G3 cell line, and all other spleen stromal cell fractions tested.This work was supported by project grants to HO from the Australian Research Council (#DP130101703) and the National Health and Medical Research Council of Australia (#585443). HL was supported by an Australian National University Postgraduate Scholarship
Stress intensity at a crack between bonded dissimilar materials
The contour integral method is extended to general boundary value problems involving imperfect bonding of dissimilar materials. The loading and restraints are shown to have a significant effect on the stress intensity. Example problems are presented to illustrate the results
One-dimensional kinetic description of nonlinear traveling-pulse (soliton) and traveling-wave disturbances in long coasting charged particle beams
This paper makes use of a one-dimensional kinetic model to investigate the
nonlinear longitudinal dynamics of a long coasting beam propagating through a
perfectly conducting circular pipe with radius . The average axial
electric field is expressed as , where and
are constant geometric factors, is the line density of beam particles, and
satisfies the 1D Vlasov equation. Detailed nonlinear
properties of traveling-wave and traveling-pulse (solitons) solutions with
time-stationary waveform are examined for a wide range of system parameters
extending from moderate-amplitudes to large-amplitude modulations of the beam
charge density. Two classes of solutions for the beam distribution function are
considered, corresponding to: (a) the nonlinear waterbag distribution, where
in a bounded region of -space; and (b) nonlinear
Bernstein-Green-Kruskal (BGK)-like solutions, allowing for both trapped and
untrapped particle distributions to interact with the self-generated electric
field .
.Comment: 42 pages, 17 figure
Entanglement distribution over the subsystems and its invariance
We study the entanglement dynamics of two qubits, each of which is embedded
into its local amplitude-damping reservoir, and the entanglement distribution
among all the bipartite subsystems including qubit-qubit, qubit-reservoir, and
reservoir-reservoir. It is found that the entanglement can be stably
distributed among all components, which is much different to the result
obtained under the Born-Markovian approximation by C. E. L\'{o}pez {\it et al.}
[Phys. Rev. Lett. \textbf{101}, 080503 (2008)], and particularly it also
satisfies an identity. Our unified treatment includes the previous results as
special cases. The result may give help to understand the physical nature of
entanglement under decoherence.Comment: 6 pages, 5 figure
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