28,110 research outputs found
Nucleation in the chiral transition with an inhomogeneous background
We consider an approximation procedure to evaluate the finite-temperature
one-loop fermionic density in the presence of a chiral background field which
systematically incorporates effects from inhomogeneities in the chiral field
through a derivative expansion. Modifications in the effective potential and
their consequences for the bubble nucleation process are discussed.Comment: 4 pages, 4 figures. To appear in the proceedings of I Latin American
Workshop on High Energy Phenomenology (LAWHEP 2005), Porto Alegre, Brazil,
1-3 Dec 200
Geometric phase and gauge theory structure in quantum computing
We discuss the presence of a geometrical phase in the evolution of a qubit
state and its gauge structure. The time evolution operator is found to be the
free energy operator, rather than the Hamiltonian operator.Comment: 5 pages, presented at Fifth International Workshop DICE2010:
Space-Time-Matter - current issues in quantum mechanics and beyond,
Castiglioncello (Tuscany), September 13-17, 201
Optimal placement of excitations and sensors by simulated annealing
The optimal placement of discrete actuators and sensors is posed as a combinatorial optimization problem. Two examples for truss structures were used for illustration; the first dealt with the optimal placement of passive dampers along existing truss members, and the second dealt with the optimal placement of a combination of a set of actuators and a set of sensors. Except for the simplest problems, an exact solution by enumeration involves a very large number of function evaluations, and is therefore computationally intractable. By contrast, the simulated annealing heuristic involves far fewer evaluations and is best suited for the class of problems considered. As an optimization tool, the effectiveness of the algorithm is enhanced by introducing a number of rules that incorporate knowledge about the physical behavior of the problem. Some of the suggested rules are necessarily problem dependent
Extracellular vesicles: A therapeutic option for liver fibrosis
Extracellular vesicles (EVs) are a heterogeneous population of small membrane vesicles released by all types of cells in both physiological and pathological conditions. EVs shuttle different types of molecules and are able to modify the behavior of target cells by various mechanisms of action. In this review, we have summarized the papers present in the literature, to our acknowledge, that reported the EV effects on liver diseases. EVs purified from serum, stem cells, and hepatocytes were investigated in different experimental in vivo models of liver injury and in particular of liver fibrosis. Despite the different EV origin and the different types of injury (toxic, ischemic, diet induced, and so on), EVs showed an anti-fibrotic effect. In particular, EVs had the capacities to inhibit activation of hepatic stellate cells, one of the major players of liver fibrosis development; to reduce inflammation and apoptosis; to counteract the oxidative stress; and to increase hepatocyte proliferation, contributing to reducing fibrosis and ameliorating liver function and morphology
- …