1,085 research outputs found
Optical anisotropy of InAs/GaSb broken-gap quantum wells
We investigate in detail the optical anisotropy of absorption of linearly polarized light in InAs/GaSb quantum wells grown on GaSb along the [001] direction, which can be used as an active region of different laser structures. The energy level positions, the wave functions, the optical matrix elements, and the absorption coefficients are calculated using the eight-band k center dot p model and the Burt-Foreman envelope function theory. In these calculations, the Schrodinger and Poisson equations are solved self-consistently taking the lattice-mismatched strain into account. We find that a realistic Hamiltonian, which has the C (2v) symmetry, results in considerable anisotropy of optical matrix elements for different directions of light polarization and different directions of the initial-state in-plane wave vector, including low-symmetry directions. We trace how the optical matrix elements and absorption are modified when spin-orbit interaction and important symmetry breaking mechanisms are taken into account (structural inversion asymmetry, bulk inversion asymmetry, and interface Hamiltonian). These mechanisms result in an almost 100% anisotropy of the absorption coefficients as the light polarization vector rotates in the plane of the structure and in a plane normal to the interfaces
Chronic Cerebral Ischaemia Forms New Cholinergic Mechanisms of Learning and Memory
The purpose of this research was a comparative analysis of cholinergic synaptic organization following learning and memory in normal and chronic cerebral ischaemic rats in the Morris water maze model. Choline acetyltransferase and protein content were determined in subpopulations of presynapses of “light” and “heavy” synaptosomal fractions of the cortex and the hippocampus, and the cholinergic projective and intrinsic systems of the brain structures were taken into consideration. We found a strong involvement of cholinergic systems, both projective and intrinsic, in all forms of cognition. Each form of cognition had an individual cholinergic molecular profile and the cholinergic synaptic compositions in the ischaemic rat brains differed significantly from normal ones. Our data demonstrated that under ischaemic conditions, instead of damaged connections new key synaptic relationships, which were stable against pathological influences and able to restore damaged cognitive functions, arose. The plasticity of neurochemical links in the individual organization of certain types of cognition gave a new input into brain pathology and can be used in the future for alternative corrections of vascular and other degenerative dementias
Comparative research of effectiveness of cellulose and fiberglass porous membrane carriers for bio sampling in veterinary and food industry monitoring
The aim of proposed research is to study the applicability of fiberglass porous membrane materials in a new strip format for dried blood storage in food industry monitoring. A comparative analysis of cellulosic and fiberglass porous membrane materials was carried out to obtain dried samples of serum or blood and the possibility of further species-specific analysi
Anticipation and Mechanisms for Resolving Interethnic Conflicts
The formation of a harmonious environment that promotes personal development is a necessary component for each person and for the functioning of the community, regardless of the form of its political structure. Creating a harmonious environment includes, among other things, working to maintain a positive inter-ethnic environment. To do this, it is necessary to conduct constant monitoring and work to support a harmonious inter-ethnic background. The article deals with the peculiarities of the influence of immersion in the interethnic environment and self-determination in the community on the individual, the influence of the communicative connection between representatives of different ethnic groups on the functioning of the community
The sensitivity to antibiotics of nosocomial strains of acinetobacter baumanii isolated in the tertiary hospitals in the Central Kazakhstan
Del 1972, en l'actual emplaçament des de 1976. D'acer pintat, mesura 5 x 3,54 x 3,20 metres.Calder, Alexander (escultor)Pla general de l'obra. La galeria Maeght va
decidir instal·lar una sucursal a Barcelona
i va triar fer-ho al carrer de Montcada.
Va obrir amb una exposició que incloïa una
peça de Calder, Quatre ales. Després fou
oferida a l'Ajuntament
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