18,370 research outputs found
Phase transitions in Ising model induced by weight redistribution on weighted regular networks
In order to investigate the role of the weight in weighted networks, the
collective behavior of the Ising system on weighted regular networks is studied
by numerical simulation. In our model, the coupling strength between spins is
inversely proportional to the corresponding weighted shortest distance.
Disordering link weights can effectively affect the process of phase transition
even though the underlying binary topological structure remains unchanged.
Specifically, based on regular networks with homogeneous weights initially,
randomly disordering link weights will change the critical temperature of phase
transition. The results suggest that the redistribution of link weights may
provide an additional approach to optimize the dynamical behaviors of the
system.Comment: 6 pages, 5 figure
Depth of pleated surfaces in toroidal cusps of hyperbolic 3-manifolds
Let be a closed essential surface in a hyperbolic 3-manifold with a
toroidal cusp . The depth of in is the maximal distance from points
of in to the boundary of . It will be shown that if is an
essential pleated surface which is not coannular to the boundary torus of
then the depth of in is bounded above by a constant depending only on
the genus of . The result is used to show that an immersed closed essential
surface in which is not coannular to the torus boundary components of
will remain essential in the Dehn filling manifold after excluding
curves from each torus boundary component of , where is a
constant depending only on the genus of the surface
Ultrasound-targeted microbubble destruction enhances AAV mediated gene transfection: human RPE cells in vitro and the rat retina in vivo
The present study was performed to investigate the efficacy and safety of Ultrasound-targeted microbubble destruction (UTMD) mediated rAAV2-EGFP to cultured human retinal pigment epithelium (RPE) cells _in vitro_ and the rat retina _in vivo_. _In vitro_ study, cultured human RPE cells were exposed to US under different conditions with or without microbubbles. Furthermore, the effect of UTMD to rAAV2-EGFP itself and the cells were evaluated. _In vivo_ study, gene transfer was examined by injecting rAAV2-EGFP into the subretinal space of the rats with or without microbubbles and then exposed to US. We investigated EGFP expression _in vivo_ via stereomicroscopy and performed quantitative analysis by Axiovision 3.1 software. HE staining and frozen sections were used to observe tissue damage and location of EGFP gene expression. _In vitro_ study, the transfection efficiency of rAAV2-EGFP increased 74.85% under the optimal UTMD conditions. Furthermore, there was almost no cytotoxicity to the cells and rAAV2-EGFP itself. _In vivo_ study, UTMD could be used safely to enhance and accelerate transgene expression of the retina. Fluorescence expression was mainly located in the layer of retina. UTMD is a promising method for gene delivery to the retina
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