Entanglement of two qubits mediated by one-dimensional plasmonic waveguides

We investigate qubit-qubit entanglement mediated by plasmons supported by one-dimensional waveguides. We explore both the situation of spontaneous formation of entanglement from an unentangled state and the emergence of driven steady-state entanglement under continuous pumping. In both cases, we show that large values for the concurrence are attainable for qubit-qubit distances larger than the operating wavelength by using plasmonic waveguides that are currently available.Comment: 4 pages, 4 figures. Minor Changes. Journal Reference added. Highlighted in Physic

Riesgos del tratamiento crónico con ácido acetilsalicílico: comparación entre las prescripciones en prevención primaria y secundaria de enfermedades cardiovasculares.

Introducción El ácido acetilsalicílico (AAS) es el antiagregante de elección en el tratamiento de la enfermedad cardiovascular. Sus beneficios en prevención secundaria (PS) han sido claramente demostrados, pero existe controversia en su uso en prevención primaria (PP): los riesgos de sufrir eventos adversos, principalmente hemorragias, pueden superar a los beneficios potenciales del tratamiento. El farmacéutico dispone de las herramientas apropiadas para la detección de problemas relacionados con los medicamentos (PRMs) tanto en PP como en PS.   Objetivos Estimar la proporción de PP vs. PS en tratamientos con AAS. Evaluar el riesgo hemorrágico y otros PRMs en ambos casos.   Métodos Estudio observacional y prospectivo en dos farmacias comunitarias. Se registraron las prescripciones de AAS, variables demográficas y farmacoterapéuticas del paciente. Cada prescripción se asignó a PP o PS según la existencia de enfermedad cardiovascular (ECV) previa. Los PRMs se evaluaron con BOT Plus Web®.       Resultados 82 dispensaciones de AAS válidas, 47 (57%) correspondían a PP y 35 (43%) a PS. Se encontró asociación estadística entre las variables PP y diabetes. Se detectaron 67 PRMs de los que el 80% (53) suponían un aumento del riesgo hemorrágico. No se apreciaron diferencias significativas para el aumento de riesgo hemorrágico entre PP o PS.   Conclusiones Encontramos mayor prevalencia de prescripción para el tratamiento crónico con AAS en PP que en PS. Observamos asociación entre PP y diabetes y entre PS y total de PRMs. No se asociación entre el aumento de riesgo hemorrágico y PP o PS

Riesgos del tratamiento crónico con ácido acetilsalicílico: comparación entre las prescripciones en prevención primaria y secundaria de enfermedades cardiovasculares.

Introducción El ácido acetilsalicílico (AAS) es el antiagregante de elección en el tratamiento de la enfermedad cardiovascular. Sus beneficios en prevención secundaria (PS) han sido claramente demostrados, pero existe controversia en su uso en prevención primaria (PP): los riesgos de sufrir eventos adversos, principalmente hemorragias, pueden superar a los beneficios potenciales del tratamiento. El farmacéutico dispone de las herramientas apropiadas para la detección de problemas relacionados con los medicamentos (PRMs) tanto en PP como en PS.   Objetivos Estimar la proporción de PP vs. PS en tratamientos con AAS. Evaluar el riesgo hemorrágico y otros PRMs en ambos casos.   Métodos Estudio observacional y prospectivo en dos farmacias comunitarias. Se registraron las prescripciones de AAS, variables demográficas y farmacoterapéuticas del paciente. Cada prescripción se asignó a PP o PS según la existencia de enfermedad cardiovascular (ECV) previa. Los PRMs se evaluaron con BOT Plus Web®.       Resultados 82 dispensaciones de AAS válidas, 47 (57%) correspondían a PP y 35 (43%) a PS. Se encontró asociación estadística entre las variables PP y diabetes. Se detectaron 67 PRMs de los que el 80% (53) suponían un aumento del riesgo hemorrágico. No se apreciaron diferencias significativas para el aumento de riesgo hemorrágico entre PP o PS.   Conclusiones Encontramos mayor prevalencia de prescripción para el tratamiento crónico con AAS en PP que en PS. Observamos asociación entre PP y diabetes y entre PS y total de PRMs. No se asociación entre el aumento de riesgo hemorrágico y PP o PS

Sildenafil restores cognitive function without affecting β-amyloid burden in a mouse model of Alzheimer's disease

Abstract BACKGROUND AND PURPOSE: Inhibitors of phosphodiesterase 5 (PDE5) affect signalling pathways by elevating cGMP, which is a second messenger involved in processes of neuroplasticity. In the present study, the effects of the PDE5 inhibitor, sildenafil, on the pathological features of Alzheimer's disease and on memory-related behaviour were investigated. EXPERIMENTAL APPROACH: Sildenafil was administered to the Tg2576 transgenic mouse model of Alzheimer's disease and to age-matched negative littermates (controls). Memory function was analysed using the Morris water maze test and fear conditioning tasks. Biochemical analyses were performed in brain lysates from animals treated with saline or with sildenafil. KEY RESULTS: Treatment of aged Tg2576 animals with sildenafil completely reversed their cognitive impairment. Such changes were accompanied in the hippocampus by a reduction of tau hyperphosphorylation and a decrease in the activity of glycogen synthase kinase 3β (GSK3β) and of cyclin-dependent kinase 5 (CDK5) (p25/p35 ratio). Moreover, sildenafil also increased levels of brain-derived neurotrophic factor (BDNF) and the activity-regulated cytoskeletal-associated protein (Arc) in the hippocampus without any detectable modification of brain amyloid burden. CONCLUSIONS AND IMPLICATIONS: Sildenafil improved cognitive functions in Tg2576 mice and the effect was not related to changes in the amyloid burden. These data further strengthen the potential of sildenafil as a therapeutic agent for Alzheimer's disease

PLA2 G4E, a candidate gene for resilience in Alzheimer's disease and a new target for dementia treatment

Clinical studies revealed that some aged-individuals accumulate a significant number of histopathological Alzheimer´s disease (AD) lesions in their brain, yet without developing any signs of dementia. Animal models of AD represent suitable tools to identify genes that might promote cognitive resilience and hence, this study first set out to identify cognitively resilient individuals in the aged-Tg2576 mouse model. A transcriptomic analysis of these mice identified PLA2 G4E as a gene that might confer resistance to dementia. Indeed, a significant decrease in PLA2 G4E is evident in the brain of late-stage AD patients, whereas no such changes are observed in early stage patients with AD neuropathological lesions but no signs of dementia. We demonstrated that adeno-associated viral vector-mediated overexpression of PLA2 G4E in hippocampal neurons completely restored cognitive deficits in elderly APP/PS1 mice, without affecting the amyloid or tau pathology. These PLA2 G4E overexpressing APP/PS1 mice developed significantly more dendritic spines than sham-injected mice, coinciding with the cognitive improvement observed. Hence, these results support the idea that a loss of PLA2 G4E might play a key role in the onset of dementia in AD, highlighting the potential of PLA2 G4E overexpression as a novel therapeutic strategy to manage AD and other disorders that course with memory deficits

Role of fractal dimension in random walks on scale-free networks

Fractal dimension is central to understanding dynamical processes occurring on networks; however, the relation between fractal dimension and random walks on fractal scale-free networks has been rarely addressed, despite the fact that such networks are ubiquitous in real-life world. In this paper, we study the trapping problem on two families of networks. The first is deterministic, often called $(x,y)$-flowers; the other is random, which is a combination of $(1,3)$-flower and $(2,4)$-flower and thus called hybrid networks. The two network families display rich behavior as observed in various real systems, as well as some unique topological properties not shared by other networks. We derive analytically the average trapping time for random walks on both the $(x,y)$-flowers and the hybrid networks with an immobile trap positioned at an initial node, i.e., a hub node with the highest degree in the networks. Based on these analytical formulae, we show how the average trapping time scales with the network size. Comparing the obtained results, we further uncover that fractal dimension plays a decisive role in the behavior of average trapping time on fractal scale-free networks, i.e., the average trapping time decreases with an increasing fractal dimension.Comment: Definitive version published in European Physical Journal