Escleritis posterior bilateral Zurutuza, A.; Andonegui, J.; Berástegui, L. ...
Anales del sistema sanitario de Navarra,
08/2011, Letnik:
34, Številka:
2
Journal Article
Odprti dostop
La escleritis posterior es un proceso inflamatorio de la parte posterior de la esclera. Su prevalencia es muy baja y el diagnóstico puede resultar complicado por la ausencia de signos oculares ...externos. Es más frecuente en mujeres. Cuando aparece en pacientes jóvenes no suele tener otras patologías asociadas, pero en mayores de 55 años hasta un tercio de los casos tienen relación con alguna enfermedad sistémica, sobre todo la artritis reumatoide. El diagnóstico de esta patología puede requerir un abordaje multidisciplinar y la colaboración de oftalmólogos con neurólogos, internistas o reumatólogos. En este artículo se describe un caso de escleritis posterior bilateral idiopática.
Bilateral posterior scleritis Zurutuza, A; Andonegui, J; Berástegui, L ...
Anales del sistema sanitario de Navarra,
2011 May-Aug, 20110501, Letnik:
34, Številka:
2
Journal Article
Posterior scleritis is an inflammatory process of the posterior part of the sclera. Its prevalence is very low and its diagnosis can be complicated due to the absence of external ocular signs. It is ...more frequent in women. In young patients it does not usually have other associated pathologies, but in those over 55 years nearly one-third of the cases have a relation with some systemic disease, above all rheumatoid arthritis. The diagnosis of this pathology can require a multidisciplinary approach and the collaboration of ophthalmologists with neurologists, internists or rheumatologists. This article describes a case of idiopathic bilateral posterior scleritis.
We report an optoelectronic mixer based on chemical vapour-deposited graphene. Our device consists in a coplanar waveguide that integrates a graphene channel, passivated with an atomic ...layer-deposited Al2O3 film. With this new structure, 30 GHz optoelectronic mixing in commercially-available graphene is demonstrated for the first time. In particular, using a 30 GHz intensity-modulated optical signal and a 29.9 GHz electrical signal, we show frequency downconversion to 100 MHz. These results open promising perspectives in the domain of optoelectronics for radar and radio-communication systems.
La hipertensión arterial sistémica (HTA) es una de las enfermedades más frecuentes en los países industrializados, llegando su incidencia hasta un 30%, cifra que va en aumento por la mayor esperanza ...de vida de la población. Esta elevación de la presión arterial ocasiona o acelera los cambios en la pared vascular de los órganos diana como el riñón, cerebro, corazón y ojo.
A nivel ocular, la HTA produce lesiones en la retina, la coroides y cabeza del nervio óptico, pudiendo abarcar un amplio rango de lesiones, desde un estrechamiento vascular leve hasta una pérdida visual severa por neuropatía óptica isquémica.
La respuesta primaria de las arterias retinianas a la hipertensión arterial sistémica es un estrechamiento vascular y los signos que aparecen en el fondo de ojo en la retinopatía hipertensiva son la vasoconstricción difusa o focal, la extravasación por permeabilidad vascular aumentada y la arteriolosclerosis con engrosamiento de la pared de los vasos. Estas tres entidades son las responsables de la aparición de diferentes lesiones que van a caracterizar los estadíos de la enfermedad retiniana como son: los cruces arteriovenosos, exudados duros y algodonosos, trombosis, embolias, hemorragias en el parénquima retiniano, desprendimiento seroso de retina, edema de papila y neuropatía óptica isquémica en los casos más severos como el caso de la hipertensión arterial maligna.
We investigated thermal conductivity of free-standing reduced graphene oxide films subjected to a high-temperature treatment of up to 1000 C. It was found that the high-temperature annealing ...dramatically increased the in-plane thermal conductivity, K, of the films from 3 W/mK to 61 W/mK at room temperature. The cross-plane thermal conductivity, Kc, revealed an interesting opposite trend of decreasing to a very small value of 0.09 W/mK in the reduced graphene oxide films annealed at 1000 C. The obtained films demonstrated an exceptionally strong anisotropy of the thermal conductivity, K/Kc ~ 675, which is substantially larger even than in the high-quality graphite. The electrical resistivity of the annealed films reduced to 1 - 19 Ohms/sq. The observed modifications of the in-plane and cross-plane thermal conductivity components resulting in an unusual K/Kc anisotropy were explained theoretically. The theoretical analysis suggests that K can reach as high as ~500 W/mK with the increase in the sp2 domain size and further reduction of the oxygen content. The strongly anisotropic heat conduction properties of these films can be useful for applications in thermal management.
Controlling the energy flow processes and the associated energy relaxation rates of a light emitter is of high fundamental interest, and has many applications in the fields of quantum optics, ...photovoltaics, photodetection, biosensing and light emission. While advanced dielectric and metallic systems have been developed to tailor the interaction between an emitter and its environment, active control of the energy flow has remained challenging. Here, we demonstrate in-situ electrical control of the relaxation pathways of excited erbium ions, which emit light at the technologically relevant telecommunication wavelength of 1.5 \(\mu\)m. By placing the erbium at a few nanometres distance from graphene, we modify the relaxation rate by more than a factor of three, and control whether the emitter decays into either electron-hole pairs, emitted photons or graphene near-infrared plasmons, confined to \(<\)15 nm to the sheet. These capabilities to dictate optical energy transfer processes through electrical control of the local density of optical states constitute a new paradigm for active (quantum) photonics.
Controlling the energy flow processes and the associated energy relaxation rates of a light emitter is of fundamental interest and has many applications in the fields of quantum optics, ...photovoltaics, photodetection, biosensing and light emission. Advanced dielectric, semiconductor and metallic systems have been developed to tailor the interaction between an emitter and its environment. However, active control of the energy flow from an emitter into optical, electronic or plasmonic excitations has remained challenging. Here, we demonstrate in situ electrical control of the relaxation pathways of excited erbium ions, which emit light at the technologically relevant telecommunication wavelength of 1.5 μm. By placing the erbium at a few nanometres distance from graphene, we modify the relaxation rate by more than a factor of three, and control whether the emitter decays into electron–hole pairs, emitted photons or graphene near-infrared plasmons, confined to <15 nm from the graphene sheet. These capabilities to dictate optical energy transfer processes through electrical control of the local density of optical states constitute a new paradigm for active (quantum) photonics and can be applied using any combination of light emitters and two-dimensional materials.
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