97,385 research outputs found
Experimental pharmacological research regarding some new quinazolin-4-ones derivatives
A series of new compounds with quinazolin-4-one structure, synthesized by the Pharmaceutical Chemistry Department of the Faculty of Pharmacy of the University of Medicine and Pharmacy “Carol Davila” Bucharest, was studied. Five of them were selected, conventionally named S1, S2, S3, S4, S5, and investigated in terms of their potential influence on the central nervous system (CNS). For this purpose, the antidepressant effect was determined using the forced swimming test; the anxiolytic/ anxiogenic effect was determined using the suspended plus-shaped maze (Ugo Basile); the effect on the motor activity was determined using the Ugo Basile activity cage; and the potential analgesic effect was investigated using the hot plate test (Ugo Basile). Compounds S3 and S5 lowered the motor activity and showed an anxiolytic effect, while S1 and S2 proved to have antidepressant and analgesic effects.
A good correlation between antidepressant and analgesic effects was observed, consistent with the fact that analgesic drugs, by increasing norepinephrine and serotonin levels in the pain inhibiting descendent pathways, can be used as co-analgesics in therapy
Ugo Fano and Shape Resonances
Ugo Fano has been a leader in theoretical Physics in the XX century giving
key contributions to our understanding of quantum phenomena. He passed away on
13 February 2001 after 67 years of research activity. I will focus on his
prediction of the quantum interference effects to understand the high-energy
photoabsorption cross section giving the Fano lineshapes. The Fano results led
to the theoretical understanding of shape resonances (known also as Feshbach
resonances) that should be better called Fano resonances. Finally I will show
that today this Fano quantum interference effect is behind several new physical
phenomena in different fields.Comment: 7 pages 2 figure Submitted "X-rays and Inner Shell Processes" AIP
conference proceedings 2002
Solving Unconstrained Global Optimization Problems via Hybrid Swarm Intelligence Approaches
Stochastic global optimization (SGO) algorithms such as the particle swarm optimization (PSO) approach have become popular for solving unconstrained global optimization (UGO) problems. The PSO approach, which belongs to the swarm intelligence domain, does not require gradient information, enabling it to overcome this limitation of traditional nonlinear programming methods. Unfortunately, PSO algorithm implementation and performance depend on several parameters, such as cognitive parameter, social parameter, and constriction coefficient. These parameters are tuned by using trial and error. To reduce the parametrization of a PSO method, this work presents two efficient hybrid SGO approaches, namely, a real-coded genetic algorithm-based PSO (RGA-PSO) method and an artificial immune algorithm-based PSO (AIA-PSO) method. The specific parameters of the internal PSO algorithm are optimized using the external RGA and AIA approaches, and then the internal PSO algorithm is applied to solve UGO problems. The performances of the proposed RGA-PSO and AIA-PSO algorithms are then evaluated using a set of benchmark UGO problems. Numerical results indicate that, besides their ability to converge to a global minimum for each test UGO problem, the proposed RGA-PSO and AIA-PSO algorithms outperform many hybrid SGO algorithms. Thus, the RGA-PSO and AIA-PSO approaches can be considered alternative SGO approaches for solving standard-dimensional UGO problems
Entanglement in dissipative dynamics of identical particles
Entanglement of identical massive particles recently gained attention,
because of its relevance in highly controllable systems, e.g. ultracold gases.
It accounts for correlations among modes instead of particles, providing a
different paradigm for quantum information. We prove that the entanglement of
almost all states rarely vanishes in the presence of noise, and analyse the
most relevant noise in ultracold gases: dephasing and particle losses.
Furthermore, when the particle number increases, the entanglement decay can
turn from exponential into algebraic
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