325 research outputs found

    Design of a Broadband Amplifier for High Speed Applications

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    This paper provides comprehensive insight into the design approach followed for an amplifier dedicated to high speed base band signals. To demonstrate the methodology, an amplifier consisting of nine PHEMT cascode cells within a distributed amplifier topology was designed. The resulting frequency response is 40 GHz at the 3-dB point, and the output voltage for a 43 Gbps eye diagram is 7.3 Vpp at the chip terminal

    Representation of differential operators in wavelet basis

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    AbstractExisting work on the representation of operators in one-dimensional, compactly-supported, orthonormal wavelet bases is extended to two dimensions. The nonstandard form of the representation of operators is given in separable two-dimensional, periodic, orthonormal wavelet bases. The matrix representation of the partial-differential operators ∂x and ∂y are constructed and a closed form formula for the matrix representation of a general partial-differential operator g(∂x, ∂y) is derived, where g is an analytic function

    Rituximab in the treatment of inflammatory myopathies: a review

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    Several uncontrolled studies have encouraged the use of rituximab (RTX) in patients with myositis. Unfortunately, the first placebo-phase trial to assess the efficacy of RTX in refractory myositis did not show a significant difference between the two treatment groups, and doubts have been expressed about its study design. In this review we present an up-to-date overview of the reported experiences of RTX therapy in myositis. A PubMed search was performed to find all the available cases of refractory myositis patients treated with RTX up to July 2015. The following terms were assessed: inflammatory myopathies OR anti-synthetase syndrome OR polymyositis OR dermatomyositis AND RTX. A total of 48 studies were included. We identified 458 patients with myositis treated with RTX. We found a rate of response to RTX of 78.3%. RTX can play a role in the management of patients with myositis, at least in those with positive myositis-specific autoantibodies

    Prise en charge des complications des fistules artério-veineuses pour hémodialyse chronique

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    La fistule artério-veineuse native est l'accès vasculaire de choix pour  l'hémodialyse chronique en raison de sa longévité, son taux faible de complication et de mortalité par rapport aux pontages artério-veineux et aux cathéters. Cependant, il arrive assez souvent que l'on assiste à des complications qui sont dominées par la sténose et la thrombose. C'est une étude rétrospective des complications ayants survenues pour 31 fistules artério-veineuses pour hémodialyse chronique des 200 fistules réalisées chez 200 patients au sein du service de chirurgie vasculaire du CHU Hassan II de Fès sur une période de trois ans, étendue de Janvier 2007 à  Décembre 2009. Ces complications ont été présentés par les thrombosesdans 14 cas soit 45,15% de l'ensemble des complications, les sténoses dans 4 cas (12,90%,) les anévrismes dans 4 cas (12,90%), les  complications ischémiques dans 3 cas (9,67%), l'infection dans 3 cas (9,67%), l'hémorragie dans 2 cas (6,45%) et l' hyperdébit dans un seul cas soit 3,22%. On a pu conserver 22 fistules soit 70,96% par traitement chirurgical ou endovasculaire, on a confectionné une nouvelle fistule dans 8cas soit 25,80%, et on a adressé une patiente (3,22%) pour pose d'un cathéter veineux tunnelisé permanent. Les complications des fistules artério-veineuses pour l'hémodialyse chronique sont la principale cause de morbidité chez les patients hémodialysés, il est donc important de s'impliquer lors de leur création, et de donner un maximum d'attention quand ils sont manipulés. Ceci suggère la mise en place d'un programme de surveillance de ces fistules en raison de l'impact des complications sur la morbi-mortalité du patient hémodialysé et sur le plan financier

    PGC-1α controls mitochondrial biogenesis and dynamics in lead-induced neurotoxicity

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    Due to its role in regulation of mitochondrial function, PGC1α is emerging as an important player in ageing and neurodegenerative disorders. PGC1α exerts its neuroprotective effects by promoting mitochondrial biogenesis (MB) and functioning. However, the precise regulatory role of PGC1α in the control of mitochondrial dynamics (MD) and neurotoxicity is still unknown. Here we elucidate the role of PGC1α in vitro and in vivo in the regulatory context of MB and MD in response to lead (II) acetate as a relevant model of neurotoxicity. We show that there is an adaptive response (AR) to lead, orchestrated by the BAP31-calcium signalling system operating between the ER and mitochondria. We find that this hormetic response is controlled by a cell-tolerated increase of PGC1α expression, which in turn induces a balanced expression of fusion/fission genes by binding to their promoters and implying its direct role in regulation of MD. However, dysregulation of PGC1α expression through either stable downregulation or overexpression, renders cells more susceptible to lead insult leading to mitochondrial fragmentation and cell death. Our data provide novel evidence that PGC1α expression is a key regulator of MD and the maintenance of tolerated PGC1α expression may offer a promising strategy for neuroprotective therapies.España Ministerio de Economía y Competitividad SAF2012-3902

    The contribution of deep learning to the semantic segmentation of 3D point-clouds in urban areas

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    peer reviewedSemantic segmentation in a large-scale urban environment is crucial for a deep and rigorous understanding of urban environments. The development of Lidar tools in terms of resolution and precision offers a good opportunity to satisfy the need of developing 3D city models. In this context, deep learning revolutionizes the field of computer vision and demonstrates a good performance in semantic segmentation. To achieve this objective, we propose to design a scientific methodology involving a method of deep learning by integrating several data sources (Lidar data, aerial images, etc) to recognize objects semantically and automatically. We aim at extracting automatically the maximum amount of semantic information in a urban environment with a high accuracy and performance

    Composición en ácidos grasos de fosfolípidos y triacilgliceroles de la carne del salmonete gris de labios gruesos (Chelon labrosus) que vive en agua geotérmica y agua de mar tunecina: un estudio comparativo

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    This study was conducted to elucidate the effects of rearing conditions on the composition of different phospholipid (PLs) classes and triacylglycerols (TAG) of the thick-lipped grey mullet (Chelon labrosus), a muscle originating from seawater and geothermal water. The major fatty acids in the examined lipid classes of the two fish groups were palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n-9), linoleic acid (C18:2n-6), arachidonic acid (C20:4n-6), eicosapentaenoic acid (C20:5n-3), and docosahexaenoic acid (C22:6n-3). The analyses demonstrated that the fatty acid profiles of the PL classes in the seawater fish group were characterized by the predominance of n-3 polyunsaturated fatty acids (PUFA). By contrast, in geothermal fish, the distribution of PUFA series proportions differed between the phospholipid fractions. It was found PUFA n-3 was particularly abundant in PS and PI, while the n-6 series dominated the PC and PE PUFA group. Nonetheless, it was found that neutral lipid fatty acids were characterized by saturated fatty acids (SFA) followed by monounsaturated fatty acids (MUFA) in the seawater fish and by PUFA in the geothermal fish. The results presented here give useful information on the role of lipid classes in the physiological adaptation of C. labrosus which can serve for the optiminzation of these aquaculture systems.Este estudio se llevó a cabo para dilucidar los efectos de las condiciones de cría sobre la composición de diferentes clases de fosfolípidos (PL) y triacilgliceroles (TAG) del músculo de salmonetes de labios gruesos (Chelon labrosus) procedentes de agua de mar y de agua geotérmica. Los principales ácidos grasos en las clases de lípidos examinados de los dos grupos de peces fueron, palmítico (C16:0), esteárico (C18:0), oleico (C18:1n-9), linoleico (C18:2n-6), araquidónico (C20:4n-6), eicosapentaenoico (C20:5n-3) y ácido docosahexaenoico (C22:6n-3). Las determinaciones mostraron que los perfiles de ácidos grasos de los PL, en el grupo de peces de agua de mar, se caracterizaron por el predominio de ácidos grasos poliinsaturados n-3 (PUFA). Por el contrario, en los peces geotérmicos, la distribución de las proporciones de las series de PUFA difirió entre las fracciones de fosfolípidos. Se encontró que los PUFA n-3 eran particularmente abundantes en PS y PI, mientras que la serie n-6 dominaba el grupo de PUFA PC y PE. No obstante, se encontró que en lipidos neutros, los mayoritarios son los ácidos grasos saturados (SFA) seguidos de los ácidos grasos monoinsaturados (MUFA) en el pescado de agua de mar y los PUFA en el pescado geotérmico. Los resultados actuales brindan información útil sobre el papel de las clases de lípidos en la adaptación fisiológica de C. labrosus que puede servir para la optimización de estos sistemas de acuicultura

    OBSERVATION OF AN ISOKINETIC TEMPERATURE AND COMPENSATION EFFECT FOR HIGH TEMPERATURE CRUDE OIL FOULING

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    The initial fouling rates of four crude oils were determined at a nominal bulk temperature of 315 °C, an initial heated wall shear stress of 13 Pa, and initial surface temperatures between 375 and 445 °C. These initial fouling rates ranged from 1.3(10-6) to 7.8(10-5) m2 K/kJ. Corresponding Arrhenius plots were linear with the initial fouling rates passing through an isokinetic temperature of 407.5 °C. A plot of the natural logarithm of the preexponential factors (7.6(104) – 5.2(1015) m2 K/kJ) versus the apparent activation energies (128 – 269 kJ/mol) was also linear, confirming the validity of the isokinetic temperature and the presence of the compensation effect. Below the isokinetic temperature, the relative fouling rates were Crude Oil C \u3e Crude Oil A \u3e Crude Oil D \u3e Crude Oil B; above the isokinetic temperature, the relative fouling rates were reversed (Crude Oil B \u3e Crude Oil D \u3e Crude Oil A \u3e Crude Oil C). Chemical characterization of a fouling deposit suggested that the dominant fouling mechanism at these conditions was coking with significant contributions from sedimentation (iron sulfide) and corrosion (~340 μm/yr) of the 304 stainless steel test material

    OBSERVATION OF AN ISOKINETIC TEMPERATURE AND COMPENSATION EFFECT FOR HIGH TEMPERATURE CRUDE OIL FOULING

    Get PDF
    The initial fouling rates of four crude oils were determined at a nominal bulk temperature of 315 °C, an initial heated wall shear stress of 13 Pa, and initial surface temperatures between 375 and 445 °C. These initial fouling rates ranged from 1.3(10-6) to 7.8(10-5) m2 K/kJ. Corresponding Arrhenius plots were linear with the initial fouling rates passing through an isokinetic temperature of 407.5 °C. A plot of the natural logarithm of the preexponential factors (7.6(104) – 5.2(1015) m2 K/kJ) versus the apparent activation energies (128 – 269 kJ/mol) was also linear, confirming the validity of the isokinetic temperature and the presence of the compensation effect. Below the isokinetic temperature, the relative fouling rates were Crude Oil C \u3e Crude Oil A \u3e Crude Oil D \u3e Crude Oil B; above the isokinetic temperature, the relative fouling rates were reversed (Crude Oil B \u3e Crude Oil D \u3e Crude Oil A \u3e Crude Oil C). Chemical characterization of a fouling deposit suggested that the dominant fouling mechanism at these conditions was coking with significant contributions from sedimentation (iron sulfide) and corrosion (~340 μm/yr) of the 304 stainless steel test material
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