90 research outputs found

    Linfosarcoma cutáneo : a propósito de un caso

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    El objeto de este trabajo es la exposición de un caso de linfosareoma cutáneo, su diagnóstico citológico y la técnica utilizada.The object of this work is the exposition of one case of cutaneous lymphosarcoma and its cytologic diagnosis and technique

    Kinetostatic Analysis and Solution Classification of a Planar Tensegrity Mechanism

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    Tensegrity mechanisms have several interesting properties that make them suitable for a number of applications. Their analysis is generally challenging because the static equilibrium conditions often result in complex equations. A class of planar one-degree-of-freedom (dof) tensegrity mechanisms with three linear springs is analyzed in detail in this paper. The kinetostatic equations are derived and solved under several loading and geometric conditions. It is shown that these mechanisms exhibit up to six equilibrium configurations, of which one or two are stable. Discriminant varieties and cylindrical algebraic decomposition combined with Groebner base elimination are used to classify solutions as function of the input parameters.Comment: 7th IFToMM International Workshop on Computational Kinematics, May 2017, Poitiers, France. 201

    A general method for the numerical computation of manipulator singularity sets

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    The analysis of singularities is central to the development and control of a manipulator. However, existing methods for singularity set computation still concentrate on specific classes of manipulators. The absence of general methods able to perform such computation on a large class of manipulators is problematic because it hinders the analysis of unconventional manipulators and the development of new robot topologies. The purpose of this paper is to provide such a method for nonredundant mechanisms with algebraic lower pairs and designated input and output speeds. We formulate systems of equations that describe the whole singularity set and each one of the singularity types independently, and show how to compute the configurations in each type using a numerical technique based on linear relaxations. The method can be used to analyze manipulators with arbitrary geometry, and it isolates the singularities with the desired accuracy. We illustrate the formulation of the conditions and their numerical solution with examples, and use 3-D projections to visualize the complex partitions of the configuration space induced by the singularities.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness under contract DPI2010-18449, and by a Juan de la Cierva contract supporting the fourth author.Peer Reviewe

    The CUIK suite: Analyzing the motion closed-chain multibody systems

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    Many situations in robotics require the analysis of the motions of complex multibody systems. These are sets of articulated bodies arising in a variety of devices, including parallel manipulators, multifingered hands, or reconfigurable mechanisms, but they appear in other domains too as mechanical models of molecular compounds or nanostructures. Closed kinematic chains arise frequently in such systems, either due to their morphology or due to geometric or contact constraints to fulfill during operation, giving rise to configuration spaces of an intricate structure. Despite appearing very often in practice, there is a lack of general software tools to analyze and represent such configuration spaces. Existing packages are oriented either to open-chain systems or to specific robot types, which hinders the analysis and development of innovative manipulators. This article describes the CUIK suite, a software toolbox for the kinematic analysis of general multibody systems. The implemented tools can isolate the valid configurations, determine the motion range of the whole multibody system or of some of its parts, detect singular configurations leading to control or dexterity issues, or find collision-and singularity-free paths between configurations. The toolbox has applications in robot design and programming and is the result of several years of research and development within the Kinematics and Robot Design group at IRI, Barcelona. It is available under GPLv3 license from http://www.iri.upc.edu/cuik.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness under project DPI2010-18449, by a Juan de la Cierva fellowship supporting Montserrat Manubens, and by a CSIC JAE-Doc fellowship partially funded by the ESF supporting Leonard Jaillet.Peer Reviewe

    The CUIK Suite: Analyzing the Motion Closed-Chain Multibody Systems

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    Tomografía de emisión de fotones cerebral. Valor del índice corticocerebeloso y patrones gammagráficos en la enfermedad de Alzheimer y otras afecciones

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    Brain single photon emission computed tomography (SPECT) with 99mTc-HMPAO is a diagnostic tool for evaluating regional cerebral blood flow. Recently, the diagnostic possibilities of the method are being investigated in some neurologic disorders, such as cerebrovascular accidents, seizures and dementia. This work has been carried out with 54 subjects, 9 healthy volunteers and 45 patients (31 dementia and 14 epileptics), in order to evaluate gammagraphic patterns and the utility of cortico/cerebellar activity indexes. An interesting diagnostic finding is a significant decrease (p less than 0.001) in perfusion of temporoparietal regions in the patients with Alzheimer's disease in relation with the healthy volunteers' group. We have not found significant changes in perfusion in the group of epileptic patients during the interictal phase. We conclude emphasizing the interest of the SPECT in the differential diagnosis of dementia

    Image analysis technique as a tool to identify morphological changes in Trametes versicolor pellets according to exopolysaccharide or laccase production

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    Image analysis technique was applied to identify morphological changes of pellets from white-rot fungus Trametes versicolor on agitated submerged cultures during the production of exopolysaccharide (EPS) or ligninolytic enzymes. Batch tests with four different experimental conditions were carried out. Two different culture media were used, namely yeast medium or Trametes defined medium and the addition of lignolytic inducers as xylidine or pulp and paper industrial effluent were evaluated. Laccase activity, EPS production, and final biomass contents were determined for batch assays and the pellets morphology was assessed by image analysis techniques. The obtained data allowed establishing the choice of the metabolic pathways according to the experimental conditions, either for laccase enzymatic production in the Trametes defined medium, or for EPS production in the rich Yeast Medium experiments. Furthermore, the image processing and analysis methodology allowed for a better comprehension of the physiological phenomena with respect to the corresponding pellets morphological stages.The authors acknowledge Portucel-Empresa de Celulose e Papel, Cacia, Portugal, SA for the pulp and paper Kraft effluent used in this work. This work was funded by FEDER Funds through the Programa Operacional Factores de Competitividade-COMPETE, and national funds through FCT-Fundacao para a Ciencia e a Tecnologia under the projects PEst-C/CTM/LA/0011/2013 and PEst-C/EQB/LA0020/2013. A. P. M. Tavares acknowledge the financial support of (Programme Ciencia 2008) FCT, Portugal

    Polymorphisms in MDM2 and TP53 genes and risk of developing therapy-related myeloid neoplasms

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    One of the most severe complications after successful cancer therapy is the development of therapy-related myeloid neoplasms (t-MN). Constitutional genetic variation is likely to impact on t-MN risk. We aimed to evaluate if polymorphisms in the p53 pathway can be useful for predicting t-MN susceptibility. First, an association study revealed that the Pro variant of the TP53 Arg72Pro polymorphism and the G allele of the MDM2 SNP309 were associated with t-MN risk. The Arg variant of TP53 is more efficient at inducing apoptosis, whereas the Pro variant is a more potent inductor of cell cycle arrest and DNA repair. As regards MDM2 SNP309, the G allele is associated with attenuation of the p53 apoptotic response. Second, to evaluate the biological effect of the TP53 polymorphism, we established Jurkat isogenic cell lines expressing p53Arg or p53Pro. Jurkat p53Arg cells presented higher DNA damage and higher apoptotic potential than p53Pro cells, after treatment with chemotherapy agents. Only p53Pro cells presented t(15;17) translocation and del(5q). We suggest that failure to repair DNA lesions in p53Arg cells would lead them to apoptosis, whereas some p53Pro cells, prone to cell cycle arrest and DNA repair, could undergo misrepair, generating chromosomal abnormalities typical of t-MN

    TLR4, but Neither Dectin-1 nor Dectin-2, Participates in the Mollusk Hemocyanin-Induced Proinflammatory Effects in Antigen-Presenting Cells From Mammals

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    Funding This study was supported by CONICYT-CHILE FONDECYT Regular Grant 1151337 to MB. FONDAP 15130011 to SL. CONICYT-CHILE National Ph.D. Fellowships were awarded to JJ (CONICYT-PCHA/Doctorado Nacional/2013-21130683) and to JO-Q (CONICYT-PFCHA/Doctorado Nacional/2017-21171588). FS holds a postdoctoral fellowship from the National Commission for Scientific and Technological Research (CONICYT), Chile. Funding was provided by the Wellcome Trust (102705, 097377), the MRC Centre for Medical Mycology and the University of Aberdeen (MR/N006364/1) to GB. Acknowledgments We thank Dr. María Rosa Bono, Dr. Sergio Vargas, and Dr. Juan Carlos Aguillón from Universidad de Chile and Dr. Mónica Imarai from Universidad de Santiago, Chile for helpful comments.Peer reviewedPublisher PD
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