187 research outputs found

    Prevencion de signos de tolerancia y abstinencia opioide por clonidina, nimodipino y diltiazem

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    Tesis Universidad Complutense de Madrid, Facultad de Ciencias Biológicas, Departamento de Biología Animal II (Fisiología Animal), leída el 17-11-1991Depto. de Genética, Fisiología y MicrobiologíaFac. de Ciencias BiológicasTRUEpu

    Building memristor applications: from device model to circuit design

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    Since the memristor was first built in 2008 at HP Labs, no end of devices and models have been presented. Also, new applications appear frequently. However, the integration of the device at the circuit level is not straightforward, because available models are still immature and/or suppose high computational loads, making their simulation long and cumbersome. This study assists circuit/systems designers in the integration of memristors in their applications, while aiding model developers in the validation of their proposals. We introduce the use of a memristor application framework to support the work of both the model developer and the circuit designer. First, the framework includes a library with the best-known memristor models, being easily extensible with upcoming models. Systematic modifications have been applied to these models to provide better convergence and significant simulations speedups. Second, a quick device simulator allows the study of the response of the models under different scenarios, helping the designer with the stimuli and operation time selection. Third, fine tuning of the device including parameters variations and threshold determination is also supported. Finally, SPICE/Spectre subcircuit generation is provided to ease the integration of the devices in application circuits. The framework provides the designer with total control overconvergence, computational load, and the evolution of system variables, overcoming usual problems in the integration of memristive devices

    Temperature Sensor Placement Including Routing Overhead and Sampling Inaccuracies

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    Dynamic thermal management techniques require a collection of on-chip thermal sensors that imply a significant area and power overhead. Finding the optimum number of temperature monitors and their location on the chip surface to optimize accuracy is an NP-hard problem. In this work we improve the modeling of the problem by including area, power and networking constraints along with the consideration of three inaccuracy terms: spatial errors, sampling rate errors and monitor-inherent errors. The problem is solved by the simulated annealing algorithm. We apply the algorithm to a test case employing three different types of monitors to highlight the importance of the different metrics. Finally we present a case study of the Alpha 21364 processor under two different constraint scenarios

    A CAD framework for the characterization and use of Memristor models

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    In the recent years the missing fourth component, the memristor, was successfully synthesized. However, the mathematical complexity and variety of the models behind this component, in addition to the existence of convergence problems in the simulations, make the design of memristor-based applications long and difficult. In this work we present a memristor model characterization framework which supports the automated generation of subcircuit files. The proposed environment allows the designer to choose and parameterize the memristor model that best suits for a given application. The framework carries out characterizing simulations in order to study the possible non-convergence problems, solving the dependence on the simulation conditions and guaranteeing the functionality and performance of the design. Additionally, the occurrence of undesirable effects related to PVT variations is also taken into account. By performing a Monte Carlo or a corner analysis, the designer is aware of the safety margins which assure the correct device operation

    Four-injector variability modeling of FinFET predictive technology models

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    The usual way of modeling variability using threshold voltage shift and drain current amplification is becoming inaccurate as new sources of variability appear in sub-22nm devices. In this work we apply the four-injector approach for variability modeling to the simulation of SRAMs with predictive technology models from 20nm down to 7nm nodes. We show that the SRAMs, designed following ITRS roadmap, present stability metrics higher by at least 20% compared to a classical variability modeling approach. Speed estimation is also pessimistic, whereas leakage is underestimated if sub-threshold slope and DIBL mismatch and their correlations with threshold voltage are not considered

    A tool for the automatic analysis of single events effects on electronic circuits

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    Nowadays integrated circuit reliability is challenged by both variability and working conditions. Environmental radiation has become a major issue when ensuring the circuit correct behavior. The required radiation and later analysis performed to the circuit boards is both fund and time expensive. The lack of tools which support pre-manufacturing radiation hardness analysis hinders circuit designers tasks. This paper describes an extensively customizable simulation tool for the characterization of radiation effects on electronic systems. The proposed tool can produce an in depth analysis of a complete circuit in almost any kind of radiation environment in affordable computation times

    Conjugation inhibitors effectively prevent plasmid transmission in natural environments

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    Plasmid conjugation is a major route for the spread of antibiotic resistance genes. Inhibiting conjugation has been proposed as a feasible strategy to stop or delay the propagation of antibiotic resistance genes. Several compounds have been shown to be conjugation inhibitors in vitro, specifically targeting the plasmid horizontal transfer machinery. However, the in vivo efficiency and the applicability of these compounds to clinical and environmental settings remained untested. Here we show that the synthetic fatty acid 2-hexadecynoic acid (2-HDA), when used as a fish food supplement, lowers the conjugation frequency of model plasmids up to 10-fold in controlled water microcosms. When added to the food for mice, 2-HDA diminished the conjugation efficiency 50-fold in controlled plasmid transfer assays carried out in the mouse gut. These results demonstrate the in vivo efficiency of conjugation inhibitors, paving the way for their potential application in clinical and environmental settings. IMPORTANCE The spread of antibiotic resistance is considered one of the major threats for global health in the immediate future. A key reason for the speed at which antibiotic resistance spread is the ability of bacteria to share genes with each other. Antibiotic resistance genes harbored in plasmids can be easily transferred to commensal and pathogenic bacteria through a process known as bacterial conjugation. Blocking conjugation is thus a potentially useful strategy to curtail the propagation of antibiotic resistance. Conjugation inhibitors (COINS) are a series of compounds that block conjugation in vitro. Here we show that COINS efficiently block plasmid transmission in two controlled natural environments, water microcosms and the mouse gut. These observations indicate that COIN therapy can be used to prevent the spread of antibiotic resistance.Acknowledgments: The work performed by the de la Cruz research group was supported by the European Union Seventh Framework Program (FP7-HEALTH-2011-single-stage) “Evolution and Transfer of Antibiotic Resistance” (EvoTAR), grant agreement number 282004. The work performed by C.P.-G. and M.G. was supported by Ph.D. fellowships funded by the University of Cantabria. The work performed by the B.G.-Z. laboratory was supported by The EFFORT project (www.effort-against-amr.eu) FP7-KBBE-2013-7, grant agreement 613754

    Reconfigurable writing architecture for reliable RRAM operation in wide temperature ranges

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    Resistive switching memories [resistive RAM (RRAM)] are an attractive alternative to nonvolatile storage and nonconventional computing systems, but their behavior strongly depends on the cell features, driver circuit, and working conditions. In particular, the circuit temperature and writing voltage schemes become critical issues, determining resistive switching memories performance. These dependencies usually force a design time tradeoff among reliability, device endurance, and power consumption, thereby imposing nonflexible functioning schemes and limiting the system performance. In this paper, we present a writing architecture that ensures the correct operation no matter the working temperature and allows the dynamic load of application-oriented writing profiles. Thus, taking advantage of more efficient configurations, the system can be dynamically adapted to overcome RRAM intrinsic challenges. Several profiles are analyzed regarding power consumption, temperature-variations protection, and operation speed, showing speedups near 700x compared with other published drivers

    Publicidad Y Educación Sanitaria

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    ResumenLa educación sanitaria y la publicidad tienen un objetivo común: influir en la conducta humana. La educación sanitaria trata de inducir conductas saludables. La publicidad, en ocasiones, propugna conductas de riesgo. Se analizan aquí los anuncios insertados en las 15 revistas de máxima tirada en España durante dos meses. En total 1.726 anuncios que podrian afectar negativamente a la salud, por el producto o servicio ofertados, o por utilizar la salud como argumento persuasivo en sus textos.Hola y Lecturas tuvieron la tasa más alta de anuncios/revista. Las bebidas alcohólicas, los alimentos y los fármacos fueron los objetos más publicitados. Y más del 50% de los anuncios argumentaron directamente con la salud o el bienestar en sus textos.Los educadores sanitarios deberían conocer y enseñar el análisis critico de la publicidad, y utilizar los anuncios como instrumento didáctico, para lograr ciudadanos capaces de distanciarse y defenderse del influjo publicitario.SummaryHealth education and advertising have a common aim: to modify human behaviour. Health education tries to induce healthy behaviours. In some occasions Publicity proposes risky behaviours.Ads appearing during a two-month period in magazines of the largest circulation in Spain are analyzed here. A total of 1,726 ads which could have a negative influence on health either because of the product or service offered or for the use of health as a persuasive argument in their text, are considered.The magazines Hola and Lecturas had the highest ratio ads/magazine. Spirits, food and drugs were the most frequently advertised products. And more than 50% of the ads used health and welfare as argument for better selling.Health educators should know and teach the critical analysis of publicity, and use advertisements as a teaching tool to enable people to see through misleading advertising
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