456 research outputs found
Domain wall solution of the Skyrme model
A class of domain-wall-like solutions of the Skyrme model is obtained
analytically. They are described by the tangent hyperbolic function, which is a
special limit of the Weierstrass function. The behavior of one of the two
terms in the static energy density is like that of a domain wall. The other
term in the static energy density does not vanish but becomes constant at the
points far apart from the wall.Comment: 17 pages, 6 eps figure
Solitonic solutions of Faddeev model
An application of the equation proposed by the present authors, which is
equivalent to the static field equation of the Faddeev model, is discussed.
Under some assumptions on the space and on the form of the solution, the field
equation is reduced to a non-linear ODE of second order. By solving this
equation numerically, some solitonic solutions are obtained. It is discussed
that the product of two integers specifying solutions may be identified with
the Hopf topological invariant
Reduction of static field equation of Faddeev model
A method to solve the static field equation of the Faddeev model is
presented. For an special combination of the concerned field, we adopt a form
which is compatible with the field equation and involves two arbitrary complex
functions. As a result, the static field equation is reduced to a set of first
order partial differential equations.Comment: 8 page
Approximate vortex solution of Faddeev model
Through an Ansatz specifying the azimuthal-angle dependence of the solution,
the static field equation for vortex of the Faddeev model is converted to an
algebraic ordinary differential equation. An approximate analytic expression of
the vortex solution is explored so that the energy per unit vortex length
becomes as small as possible. It is observed that the minimum energy of vortex
is approximately proportional to the integer which specifies the solution.Comment: 9pages,4figure
Study of the cytological features of bone marrow mesenchymal stem cells from patients with neuromyelitis optica.
Neuromyelitis optica (NMO) is a refractory autoimmune inflammatory disease of the central nervous system without an effective cure. Autologous bone marrow‑derived mesenchymal stem cells (BM‑MSCs) are considered to be promising therapeutic agents for this disease due to their potential regenerative, immune regulatory and neurotrophic effects. However, little is known about the cytological features of BM‑MSCs from patients with NMO, which may influence any therapeutic effects. The present study aimed to compare the proliferation, differentiation and senescence of BM‑MSCs from patients with NMO with that of age‑ and sex‑matched healthy subjects. It was revealed that there were no significant differences in terms of cell morphology or differentiation capacities in the BM‑MSCs from the patients with NMO. However, in comparison with healthy controls, BM‑MSCs derived from the Patients with NMO exhibited a decreased proliferation rate, in addition to a decreased expression of several cell cycle‑promoting and proliferation‑associated genes. Furthermore, the cell death rate increased in BM‑MSCs from patients under normal culture conditions and an assessment of the gene expression profile further confirmed that the BM‑MSCs from patients with NMO were more vulnerable to senescence. Platelet‑derived growth factor (PDGF), as a major mitotic stimulatory factor for MSCs and a potent therapeutic cytokine in demyelinating disease, was able to overcome the decreased proliferation rate and increased senescence defects in BM‑MSCs from the patients with NMO. Taken together, the results from the present study have enabled the proposition of the possibility of combining the application of autologous BM‑MSCs and PDGF for refractory and severe patients with NMO in order to elicit improved therapeutic effects, or, at the least, to include PDGF as a necessary and standard growth factor in the current in vitro formula for the culture of NMO patient‑derived BM‑MSCs
Cross-fertilization of Ferreira's Hopfions And Electromagnetic Knots
The interrelation between Ferreira's Hopf solitons of a conformal nonlinear
model and the electromagnetic knots found by Raada et
al. is investigated. It is shown that the electromagnetic knots yield exact
solutions of the conformal nonlinear model different from those
obtained by Ferreira. Conversely, It is discussed that Ferreira's solutions
realize magnetic knots. The energy associated with these two kinds of knots are
compared. The structure of the electric charge distribution and the electric
current density associated with the magnetic knots is investigated
catena-Poly[[(2,2′-bipyridine)Âmanganese(II)]-μ3-4,4′-sulfonylÂdibenzoato]
In the title compound, [Mn(C14H8O6S)(C10H8N2)]n, the MnII ion is coordinated by four O atoms from three 4,4′-sulfonylÂdibenzoate (sdba) ligands and two N atoms from one 2,2′-bipyridine (2,2′-bipy) ligand in a distorted octaÂhedral geometry. The manganese atoms are alternately bridged either by two sdba ligands, with an Mn⋯Mn separation of 12.284 (1) Å, or by two carboxylÂate groups from two sdba ligands, with an Mn⋯Mn separation of 4.064 (1) Å, thus producing polymeric chains propagated in [101]. Weak interÂmolecular C—H⋯O hydrogen bonds and π–π interÂactions [centroid–centroid distance of 3.730 (3) Å between the aromatic rings of neighbouring polymeric chains] further stabilize the crystal packing
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