61 research outputs found

    Electroreflectance characterization of AlInGaN/GaN high-electron mobility heterostructures

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    Room temperature electroreflectance (ER) spectroscopy has been used to study the fundamental properties of AlxInyGa1xy{}_{1-x-y}N/AlN/GaN heterostructures under different applied bias. The (0001)-oriented heterostructures were grown by metal-organic vapor phase epitaxy on sapphire. The band gap energy of the AlxInyGa1xyN{}_{1-x-y}{\rm{N}} layers has been determined from analysis of the ER spectra using Aspnes' model. The obtained values are in good agreement with a nonlinear band gap interpolation equation proposed earlier. Bias-dependent ER allows one to determine the sheet carrier density of the two-dimensional electron gas and the barrier field strength

    Modem look at etiology, pathogenesis, treatment of Peyronie's disease (literature review)

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    Article reviewed global data on the etiology, epidemiology, clinical manifestations, diagnosis, staging, complications encountered, as well as available in the arsenal of methods of surgical and conservative treatment of Peyronie's disease. Details covered etiological factors pathophysiological processes of the disease. According to statistics, Peyronie's disease is quite rare in the world. However, in the world's scientific literature there are many works devoted to Peyronie's disease, in particular the methods of its treatment and control of disease complications. But to date, there is no consensus in regard to the etiology, pathogenesis and treatment of this disease. That is why further research is needed in this area to improve the detection and awareness of both men and doctors. Consequently, there is a clear need for further research of Peyronie's disease, as well as the creation of new, more effective treatments. These treatments have to be introduced into clinical practice physicians.В статье проведен обзор мировых данных по этиологии, эпидемиологии, клиническим проявлениям, диагностике, стадированию, встречающимся осложнениям, а также имеющихся в арсенале методов хирургического и консервативного лечения болезни Пейрони. Подробно освещены этиологические факторы, патофизиологические процессы данного заболевания. По статистике, болезнь Пейрони достаточно редко встречается в мире. Однако в мировой научной литературе имеется множество работ, посвящённых болезни Пейрони, в особенности методов ее лечения и борьбы с осложнениями заболевания. Но на сегодняшний день, нет единого мнения в том, что касается этиологии, патогенеза, лечения этого недуга. Именно поэтому необходимы дальнейшие исследования в этой области для улучшения выявляемости и информированности как мужчин, так и врачей. Следовательно, имеется четкая потребность в дальнейших исследованиях болезни Пейрони, а также в создании новых, более эффективных методов лечения. Эти методы лечения должны быт

    Dielectric Relaxation of La-Doped Zirconia Caused by Annealing Ambient

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    La-doped zirconia films, deposited by ALD at 300°C, were found to be amorphous with dielectric constants (k-values) up to 19. A tetragonal or cubic phase was induced by post-deposition annealing (PDA) at 900°C in both nitrogen and air. Higher k-values (~32) were measured following PDA in air, but not after PDA in nitrogen. However, a significant dielectric relaxation was observed in the air-annealed film, and this is attributed to the formation of nano-crystallites. The relaxation behavior was modeled using the Curie–von Schweidler (CS) and Havriliak–Negami (HN) relationships. The k-value of the as-deposited films clearly shows a mixed CS and HN dependence on frequency. The CS dependence vanished after annealing in air, while the HN dependence disappeared after annealing in nitrogen

    Elastic and anelastic relaxation behaviour of perovskite multiferroics I: PbZr0.53Ti0.47O3 (PZT)–PbFe0.5Nb0.5O3 (PFN)

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    Functionally impaired plasmacytoid dendritic cells and non-haematopoietic sources of type I interferon characterize human autoimmunity

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    Autoimmune connective tissue diseases arise in a stepwise fashion from asymptomatic preclinical autoimmunity. Type I interferons have a crucial role in the progression to established autoimmune diseases. The cellular source and regulation in disease initiation of these cytokines is not clear, but plasmacytoid dendritic cells have been thought to contribute to excessive type I interferon production. Here, we show that in preclinical autoimmunity and established systemic lupus erythematosus, plasmacytoid dendritic cells are not effector cells, have lost capacity for Toll-like-receptor-mediated cytokine production and do not induce T cell activation, independent of disease activity and the blood interferon signature. In addition, plasmacytoid dendritic cells have a transcriptional signature indicative of cellular stress and senescence accompanied by increased telomere erosion. In preclinical autoimmunity, we show a marked enrichment of an interferon signature in the skin without infiltrating immune cells, but with interferon-κ production by keratinocytes. In conclusion, non-hematopoietic cellular sources, rather than plasmacytoid dendritic cells, are responsible for interferon production prior to clinical autoimmunity
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