198 research outputs found

    High-Q distributed-Bragg-grating laser cavities

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    Applying Bragg gratings in Al2O3 channel waveguides, we demonstrate distributed Bragg reflectors with Q-factors of 1.02x10e6. An integrated Al2O3:Yb3+ waveguide laser with 67% slope efficiency and 47 mW output power is achieved with such cavities

    Laser interference lithography with highly accurate interferometric alignment

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    Three dimensional photonic crystals, e.g. for obtaining the so-called woodpile structure, can, among others, be fabricated by vertical stacking of multiple gratings. One of the requirements for obtaining a full photonic bandgap in such a photonic crystal is an accurate angular and lateral alignment of the successive gratings. Using laser interference lithography at 266 nm wavelength, we fabricated gratings in silicon with periods down to 300 nm. We present a method for aligning further grating exposures with respect to this grating with a 0.001 degree angular and a few nanometers lateral resolution

    Single-Frequency, Narrow-Linewidth Distributed Feedback Waveguide Laser in Al2O3:Er3+ on Silicon

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    A distributed feedback channel waveguide laser in erbium-doped aluminum oxide on a silicon substrate is reported. The optically pumped laser has a threshold pump power of 15 mW and emits 3 mW in single-frequency operation at 1545.2 nm wavelength with a slope efficiency of 6.2% and linewidth of 15 kHz

    Laser interference lithography with highly accurate interferometric alignment

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    It is shown experimentally that in laser interference lithography, by using a reference grating, respective grating layers can be positioned with high relative accuracy. A 0.001 degree angular and a few nanometers lateral resolution have been demonstrated

    Діагностика банкрутства в системі антикризового управління

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    Розглянуто питання відповідності і значимості діагностики фінансового стану кожної стадії антикризового управління. Діагностику банкрутства визначено як ретроспективне, оперативне і перспективне дослідження господарської діяльності та процесу управління підприємством, направлене на виявлення параметрів кризового розвитку за допомогою реалізації комплексу дослідницьких процедур, виявлення слабких ланок і "вузьких місць".Рассмотрены вопросы соответствия и значимости диагностики каждой стадии антикризисного управления. Диагностика банкротства определена как ретроспективное, оперативное и перспективное исследование хозяйственной деятельности и процесса управления предприятием, направленное на выявление параметров кризисного развития с помощью реализации комплекса исследовательских процедур, выявления слабых зон и «узких мест».The article analyzes issues of adequacy and role of diagnostics in all stage of anti-crisis management. The diagnostics of bankruptcy is defined as a retrospective, operative and prospective study of enterprise’s economic activity and management process that is directed to identification of parameters of crisis development by using comprehensive researches and to finding weak spots and "bottlenecks"

    Gene Expression Profiling of Histiocytic Sarcomas in a Canine Model: The Predisposed Flatcoated Retriever Dog

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    Background:The determination of altered expression of genes in specific tumor types and their effect upon cellular processes may create insight in tumorigenesis and help to design better treatments. The Flatcoated retriever is a dog breed with an exceptionally high incidence of histiocytic sarcomas. The breed develops two distinct entities of histiocytic neoplasia, a soft tissue form and a visceral form. Gene expression studies of these tumors have value for comparable human diseases such as histiocytic/dendritic cell sarcoma for which knowledge is difficult to accrue due to their rare occurrence. In addition, such studies may help in the search for genetic aberrations underlying the genetic predisposition in this dog breed.Methods:Microarray analysis and pathway analyses were performed on fresh-frozen tissues obtained from Flatcoated retrievers with localized, soft tissue histiocytic sarcomas (STHS) and disseminated, visceral histiocytic sarcomas (VHS) and on normal canine spleens from various breeds. Expression differences of nine genes were validated with quantitative real-time PCR (qPCR) analyses.Results:QPCR analyses identified the significantly altered expression of nine genes; PPBP, SpiC, VCAM1, ENPEP, ITGAD (down-regulated), and GTSF1, Col3a1, CD90 and LUM (up-regulated) in the comparison of both the soft tissue and the visceral form with healthy spleen. DAVID pathway analyses revealed 24 pathways that were significantly involved in the development of HS in general, most of which were involved in the DNA repair and replication process.Conclusions:This study identified altered expression of nine genes not yet implicated in histiocytic sarcoma manifestations in the dog nor in comparable human histiocytic/dendritic sarcomas. Exploration of the downside effect of canine inbreeding strategies for the study of similar sarcomas in humans might also lead to the identification of genes related to these rare malignancies in the human
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