236 research outputs found
Clearing extracellular alpha-synuclein from cerebrospinal fluid: A new therapeutic strategy in parkinson’s disease
This concept article aims to show the rationale of targeting extracellular α-Synuclein (α-Syn) from cerebrospinal fluid (CSF) as a new strategy to remove this protein from the brain in Parkinson’s disease (PD). Misfolding and intracellular aggregation of α-synuclein into Lewy bodies are thought to be crucial in the pathogenesis of PD. Recent research has shown that small amounts of monomeric and oligomeric α-synuclein are released from neuronal cells by exocytosis and that this extracellular alpha-synuclein contributes to neurodegeneration, progressive spreading of alpha-synuclein pathology, and neuroinflammation. In PD, extracellular oligomeric-α-synuclein moves in constant equilibrium between the interstitial fluid (ISF) and the CSF. Thus, we expect that continuous depletion of oligomeric-α-synuclein in the CSF will produce a steady clearance of the protein in the ISF, preventing transmission and deposition in the brain
Cutting short the asymmetric synthesis of the ramatroban precursor by employing ?-transaminases
La presencia del lobo ibérico (Canis lupus signatus) en ambientes humanizados de la Montaña Central Asturiana
Esta investigación, centrada en un territorio altamente humanizado de la Montaña Central de Asturias, confirma la presencia estable del lobo ibérico en un área en la que llevaba décadas ausente. El uso de técnicas de fototrampeo se ha combinado con el análisis de excrementos, la búsqueda de otras evidencias de presencia del lobo y la recopilación de información relativa a avistamientos, así como a los daños a la cabaña ganadera, introduciendo los datos en un sistema de información geográfica. El método empleado ha permitido identificar la presencia de la especie y profundizar en sus pautas de movilidad espacial, mostrando la elevada capacidad de adaptación de esta especie a la presencia humana en su actual proceso de expansión
Performance Assessment of Amorphous HfO2-Based RRAM Devices for Neuromorphic Applications
Producción CientíficaThe use of thin layers of amorphous hafnium oxide has been shown to be suitable for the manufacture of Resistive Random-Access memories (RRAM). These memories are of great interest because of their simple structure and non-volatile character. They are particularly appealing as they are good candidates for substituting flash memories. In this work, the performance of the MIM structure that takes part of a 4 kbit memory array based on 1-transistor-1-resistance (1T1R) cells was studied in terms of control of intermediate states and cycle durability. DC and small signal experiments were carried out in order to fully characterize the devices, which presented excellent multilevel capabilities and resistive-switching behavior.Ministerio de Ciencia, Innovación y Universidades (Grant, TEC2017-84321-C4-2-R )Fondos Feder y la Deutsche Forschungsgemeinschaft (German Research Foundation) ( with Project-ID 434 434 223- SFB1461)The Federal Ministry of Education and Research of Germany under (grant number 16ES1002
Analysis and control of the intermediate memory states of RRAM devices by means of admittance parameters
Producción CientíficaA thorough study of the admittance of TiN/Ti/HfO2/W bipolar resistive memories [resistance
random access memory (RRAM)] was carried out under different bias conditions and in a wide
range of ac signal frequencies. We demonstrate that a continuum of intermediate states can be
obtained by applying appropriate dc bias waveforms. Cumulative writing and erasing admittance
cycles were performed by applying triangular voltage waveform of increasing amplitude. The influence of the initial conditions on the variation of the real (conductance) and imaginary (susceptance)
components of the admittance is described. An accurate control of the memory state is achieved
both in terms of the conductance and the susceptance by means of an adequate selection of the
voltage values previously applied. A method to obtain three-dimensional voltage-conductance-susceptance state-plots is described in detail. Memory maps of admittance parameters as a function of
the programming voltage are made by sensing the memory state at 0 V, without static power consumption. The multilevel nature of RRAM devices and their suitability for neuromorphic computation are demonstrated.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (grants TEC2014-52152-C3-3-R and TEC2014- 52152-C3-1-R
Calidad percibida por usuarios de cirugía menor según nivel asistencial y profesionales que las realizan
Fundamentos: La cirugía menor es realizada actualmente por diversos profesionales en atención primaria y especializada. Como tecnología sanitaria debe ser evaluada para conseguir una eficiencia organizacional. La satisfacción del usuario es uno de los criterios de calidad. Por ello se plantea un análisis de la calidad percibida por el usuario según dónde y quién realice cirugía menor
Influences of the temperature on the electrical properties of HfO2-based resistive switching devices
Producción CientíficaIn the attempt to understand the behavior of HfO2-based resistive switching devices at low temperatures, TiN/Ti/HfO2/W metal–insulator–metal devices were fabricated; the atomic layer deposition technique was used to grow the high-k layer. After performing an electroforming process at room temperature, the device was cooled in a cryostat to carry out 100 current–voltage cycles at several temperatures ranging from the “liquid nitrogen temperature” to 350 K. The measurements showed a semiconducting behavior in high and low resistance states. In the low resistance state, a hopping conduction mechanism was obtained. The set and reset voltages increased when temperature decreased because the thermal energies for oxygen vacancies and ions were reduced. However, the temperature did not influence the power absorbed in the reset transition, indicating the local temperature in the filament controls the transition. The set transition turned from gradual to abrupt when decreasing the temperature, due to a positive feedback between the current increase and the Joule heating at low temperatures.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (Projects TEC2017-84321-C4-2-R and TEC2017-84321-C4-1-R
Aprendizaje activo en prácticas de laboratorio basadas en difracción de la luz
Memoria ID-037. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2019-2020
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