536 research outputs found

    Efficacy and Safety Of Radiation Synovectomy with Yttrium-90

    Get PDF
    In this long term retrospective study of radiation synovectomy with Yttrium-90 (Y90), we evaluated the results of 164 applications in 82 patients with RA, OA with synovitis, ankylosing spondylitis and psoriatic arthritis. Radiation synovectomy with Y90 has an overall success rate of approximately 50% and is therefore an effective alternative to surgical synovectomy in chronic synovitis which fails to respond to conservative treatment. Elbow and knee responded significantly better than shoulder and ankle joints. Patients with radiological stages from 0 to 2 showed a significantly better success rate than those with stage 3 changes. In responders, repeat therapy for recurrence of symptoms or treatment of a symptomatic corresponding symmetrical joint is advisable. Repeat therapy in a previous non-responder is associated with an unacceptably high failure rate. Therefore, when a joint fails to respond after 6 months, arthroscopy should be performed to evaluate further treatment procedures. A successful result was found in only 11 of 25 joints treated with arthroscopic synovectomy followed by radiation synovectomy within 2 weeks, indicating no benefit of this combination

    MICROMECHANICAL SENSORS USING MERGED EPITAXIAL LATERAL OVERGROWTH OF SILICON

    Get PDF
    A novel technology for manufacturing thin silicon diaphragm structures is presented. Controllability of thin silicon diaphragm is one of the most important issues in fabricating silicon micromechanical sensors whose sensitivity depends on the diaphragm thickness. This can be accomplished by epitaxial lateral overgrowth (ELO) of single crystal silicon on a patterned layer of masking material, typically Si02, combined with crystallographic etching of which etching rate depends on the crystal plane. With recent improvement of EL0 material, good quality of lOμm thick, 200μm x lOOOμm single crystal silicon was obtained with its thickness being precisely controlled by growth rate (≤ lμ m/min.). The junction leakage of the p-n junction diodes fabricated on merged EL0 silicon indicated the material quality is comparable to the substrate silicon. Using this technology, a bridge-type piezoresistive accelerometer with four beams and one proof mass was fabricated successfully. Its sensitivity and resonant frequency were comparable to the accelerometers made by other methods. They were analyzed by comparing the experimental results to a simple analytical solution as well as ANSYS stress simulator using a finite element: methods. The experimental results showed a potential application of the new technology to silicon sensor fabrication but some further refinement is remaining. Free-standing single crystal cantilever beams were fabricated using, MELO and RIE, of over lOOOμm long and 5μm by 10μm in cross section. These beams were very short, straight, indicating little residual stress. Wide, short beams were fabricated using EL0 which were also free standing. Special treatment of MELO indicated that diodes and bipolar transistors fabricated on top of the oxide stripes showed nearly ideal characteristics, hence the quality of the MELO was improved. With MELO of thicker than 5μm, no voids were observed. Test structures significantly with all surface micromachining, were designed for further development of silicon membranes

    ASAS/WHO ICF Core Sets for ankylosing spondylitis (AS): how to classify the impact of AS on functioning and health

    Get PDF
    Objective: To report on the results of a standardised consensus process agreeing on concepts typical and/or relevant when classifying functioning and health in patients with ankylosing spondylitis (AS) based on the International Classification of Functioning and Health (ICF).Methods: Experts in AS from different professional and geographical backgrounds attended a consensus conference and were divided into three working groups. Rheumatologists were selected from members of the Assessment of SpondyloArthritis international Society (ASAS). Other health professionals were recommended by ASAS members. The aim was to compose three working groups with five to seven participants to allow everybody's contribution in the discussions. Experts selected ICF categories that were considered typical and/or relevant for AS during a standardised consensus process by integrating evidence from preceding studies in alternating working group and plenary discussions. A Comprehensive ICF Core Set was selected for the comprehensive classification of functioning and a Brief ICF Core Set for application in trials.Results: The conference was attended by 19 experts from 12 countries. Eighty categories were included in the Comprehensive Core Set, which included 23 Body functions, 19 Body structures, 24 Activities and participation and 14 Environmental factors. Nineteen categories were selected for the Brief Core Set, which included 6 Body functions, 4 Body structures, 7 Activities and participation and 2 Environmental factors.Conclusion: The Comprehensive and Brief ICF Core Sets for AS are now available and aim to represent the external reference to define consequences of AS on functioning

    The bound on viscosity and the generalized second law of thermodynamics

    Full text link
    We describe a new paradox for ideal fluids. It arises in the accretion of an \textit{ideal} fluid onto a black hole, where, under suitable boundary conditions, the flow can violate the generalized second law of thermodynamics. The paradox indicates that there is in fact a lower bound to the correlation length of any \textit{real} fluid, the value of which is determined by the thermodynamic properties of that fluid. We observe that the universal bound on entropy, itself suggested by the generalized second law, puts a lower bound on the correlation length of any fluid in terms of its specific entropy. With the help of a new, efficient estimate for the viscosity of liquids, we argue that this also means that viscosity is bounded from below in a way reminiscent of the conjectured Kovtun-Son-Starinets lower bound on the ratio of viscosity to entropy density. We conclude that much light may be shed on the Kovtun-Son-Starinets bound by suitable arguments based on the generalized second law.Comment: 11 pages, 1 figure, published versio

    The Nonlinear Dynamic Conversion of Analog Signals into Excitation Patterns

    Full text link
    Local periodic perturbations induce frequency-dependent propagation waves in an excitable spatio-temporally chaotic system. We show how segments of noise-contaminated and chaotic perturbations induce characteristic sequences of excitations in the model system. Using a set of tuned excitable systems, it is possible to characterize signals by their spectral composition of excitation pattern. As an example we analyze an epileptic spike-and-wave time series.Comment: 14 pages, 5 figure

    Mechatronical Module Development on the Basis of Wave Rack Gear for Working Members Drive of Automatized Machines

    Get PDF
    Peculiarities of geometry elements synthesis of wave transmission with a rolling (cog) rack, its kinematics and simulation interaction of discrete wedge pushers with rolling rack are considered here. Principles of drive creation and systems of microprocessor control of the mechatronical module of the translation by using wave transmission with the rolling rack as well as the main appraches in design-technological preparation of its making are presented.Рассмотрены особенности синтеза геометрии элементов волновой передачи с роликовой (цевочной) рейкой, ее кинематики и моделирование взаимодействия дискретных клиновых толкателей с роликовой рейкой. Изложены принципы создания привода и системы микропроцессорного управления мехатронного модуля поступательного перемещения с использованием волновой передачи с роликовой рейкой, а также основные подходы в конструкторско-технологической подготовке его производства

    Cosmic magnetic fields from velocity perturbations in the early Universe

    Full text link
    We show, using a covariant and gauge-invariant charged multifluid perturbation scheme, that velocity perturbations of the matter-dominated dust Friedmann-Lemaitre-Robertson-Walker (FLRW) model can lead to the generation of cosmic magnetic fields. Moreover, using cosmic microwave background (CMB) constraints, it is argued that these fields can reach strengths of between 10^{-28} and 10^{-29} G at the time the dynamo mechanism sets in, making them plausible seed field candidates.Comment: 11 pages, 1 figure, IOP style, minor changes and typos correcte

    Comparison of maximal myocardial blood flow during adenosine infusion with that of intravenous dipyridamole in normal men

    Get PDF
    AbstractObjective. This study compared quantitatively the efficacy of intravenous adenosine and dipyridamole for pharmacologic induction of myocardial hyperemia.Background. Pharmacologic vasodilation is used increasingly for induction of myocardial hyperemia in conjunction with radionuclide imaging of myocardial blood flow. Although both intravenous dipyridamole and adenosine have been used, the magnitude of hyperemia induced by these agents and the hyperemia to baseline blood flow ratios have not been quantified and compared.Methods. Twenty normal volunteers were studied with dynamic positron emission tomography (PET) and intravenous nitrogen-13 ammonia. Myocardial blood flow was quantified with a two-compartment tracer kinetic model.Results. Myocardial blood flow at rest averaged 1.1 ± 0.2 ml/min per g and increased significantly to 4.4 ± 0.9 ml/min per g during adenosine and 43 ± 1.3 ml/min per g after dipyridamole administration. Hyperemia to baseline flow ratios averaged 4.3 ± 1.6 for adenosine and 4.0 ± 1.3 for dipyridamole. The average flow ratios and the maximal flows achieved were similar for both agents, but there was considerable variation in the individual response to these agents, as indicated by the range of hyperemia to baseline flow ratios (from 2.0 to 8.4 for adenosine and from 1.5 to 5.8 for dipyridamole). in addition, the hyperemic responses to dipyridamole and to adenosine differed by > 1 ml/min per g in nine subjects.Conclusions. Despite these inter- and istraindividual differences, we conclude that both agents are equally effective in producing myocardial hyperemia
    corecore