72 research outputs found
Algoritmo para el cálculo del ritmo en una señal de audio digital
En este trabajo se presenta un algoritmo para la extracción del ritmo de una señal audio digital. El ritmo está formado por los cambios de intensidad en la señal de audio. El ritmo marca cambios significativos en las señales acústicas. A través de un procedimiento de filtrado para la extracción de la envolvente de la señal de audio, luego a través de una señal cuadrada se marcan los puntos de inicio y su duración de los cambios de ritmo en la señal de audio. El algoritmo se prueba con una señal de un metrónomo de 60pps para validar esta propuesta
Asymmetric electron angular distributions in resonant dissociative photoionization of H2 with ultrashort xuv pulses
ABSTRACT: Photoelectron angular distributions from fixed-in-space H2 molecules exposed to ultrashort xuv laser pulses
have been evaluated. The theoretical method is based on the solution of the time-dependent Schrödinger
equation in a basis of stationary states that include all electronic and vibrational degrees of freedom. Asymmetric angular distributions are observed as a consequence of the delayed ionization from the H2 doubly
excited states, which induces interferences between gerade and ungerade ionization channels. The analysis of
this asymmetry as a function of pulse duration can provide an estimate of the corresponding autoionization widths
Probing H2 autoionizing states with femto and attosecond laser pulses.
ABSTRACT: We show the relevance that molecular autoionizing states display in some recent experiments related to the symmetry-breaking in molecular-frame photoelectron angular distributions in H2 when exposed to intense xuv femtosecond laser pulses, and others related to the electron (proton) localization when subject to attosecond pump-probe laser schemes. Our theoretical method solves the time-dependent Schr¨odinger equation with an spectral method that expands the wave function in terms of H2 correlated stationary vibronic states including all electronic and vibrational degrees of motion. Time-resolved asymmetric electron angular distributions are
obtained at specific proton kinetic energies due to the delayed autoionization from H2 doubly excited states, which induces interferences between gerade (1s(sigma)g) and ungerade (2p(sigma)u) ionization channels. We also study photoionization of H2 exposed to a xuv attosecond pump pulse plus a time-delayed IR femtosecond probe pulse. Fast alternating asymmetries in the proton ejection (electron localization) are obtained as a function of the time delay between the pump and the probe pulses. Finally, we deal with the process of (xuv) two-photon double ionization of H2 under the assumption of having both sequential and non-sequential absorption processes
Fox : a un año de la alternancia
Reflexiones críticas desde diversas disciplinas de las ciencias sociales acerca del primer año de gobierno de Vicente Fox Quesada. Entre los rubros que se analizan están: la política cultural, el sector rural, los jóvenes, los derechos humanos, la cultura indígena y la seguridad pública.ITESO, A.C
Attosecond control in photoionization of hydrogen molecules
ABSTRACT: We report experiments where hydrogen molecules were dissociatively ionized by an attosecond pulse train in the presence of a near-infrared field. Fragment ion yields from distinguishable ionization channels oscillate with a period that is half the optical cycle of the IR field. For molecules aligned parallel to the laser polarization axis, the oscillations are reproduced in two-electron quantum simulations, and can be explained in terms of an interference between ionization pathways that involve different harmonic orders and a laser-induced coupling between the 1s g and 2p u states of the molecular ion. This leads to a situation where the ionization probability is sensitive to the instantaneous polarization of the molecule by the IR electric field and demonstrates that we have probed the IR-induced electron dynamics with attosecond pulses
Attosecond control in photoionization of D2
ABSTRACT: We study the dissociative photoionization of D2 by an attosecond pulse train (APT) in the presence of a near-infrared (IR) field. Strong oscillations in the D+ kinetic energy release spectrum with a half period of the optical cycle of the infrared field are observed and attributed to interferences between ionization pathways involving different harmonic orders of the APT due to the IR-induced coupling between the 1s(sigma)g and 2p(sigma)u
ionization channels
Targeting aberrant DNA methylation in mesenchymal stromal cells as a treatment for myeloma bone disease
© The Author(s) 2021.Multiple myeloma (MM) progression and myeloma-associated bone disease (MBD) are highly dependent on bone marrow mesenchymal stromal cells (MSCs). MM-MSCs exhibit abnormal transcriptomes, suggesting the involvement of epigenetic mechanisms governing their tumor-promoting functions and prolonged osteoblast suppression. Here, we identify widespread DNA methylation alterations of bone marrow-isolated MSCs from distinct MM stages, particularly in Homeobox genes involved in osteogenic differentiation that associate with their aberrant expression. Moreover, these DNA methylation changes are recapitulated in vitro by exposing MSCs from healthy individuals to MM cells. Pharmacological targeting of DNMTs and G9a with dual inhibitor CM-272 reverts the expression of hypermethylated osteogenic regulators and promotes osteoblast differentiation of myeloma MSCs. Most importantly, CM-272 treatment prevents tumor-associated bone loss and reduces tumor burden in a murine myeloma model. Our results demonstrate that epigenetic aberrancies mediate the impairment of bone formation in MM, and its targeting by CM-272 is able to reverse MBD.We thank CERCA Program/Generalitat de Catalunya and the Josep Carreras Foundation for institutional support. E.B. was funded by the Spanish Ministry of Science and Innovation (grant numbers SAF2014-55942-R and SAF2017-88086-R), co-funded by FEDER funds/European Regional Development Fund (ERDF)—a way to build Europe, and a Senior Research Award from the Multiple Myeloma Research Foundation (MMRF). C.O.-d.-S. was funded by the Spanish Ministry of Science, Innovation and Universities, under grant RTI2018-094494-B-C22 (MCIU/AEI/FEDER, UE). M.G. received financial support from the Spanish FIS-ISCIII (PI15/02156 and PI19/01384) and FEDER. A.G.G is funded by a postdoctoral contract of the Asociación Española Contra el Cáncer (AECC). F.P. was funded by grants from Instituto de Salud Carlos III (ISCIII), PI17/00701 and PI19/01352, TRASCAN (EPICA and Immunocell), Fundació La Marató de TV3, the Accelerator award CRUK/AIRC/AECC joint funder-partnership, CIBERONC (CB16/12/00489) and co-financed with FEDER funds and Fundación Ramón Areces (PREMAMM)
Tuning melatonin receptor subtype selectivity in oxadiazolone-based analogues: Discovery of QR2 ligands and NRF2 activators with neurogenic properties
New multi-target indole and naphthalene derivatives containing the oxadiazolone scaffold as a bioisostere
of the melatonin acetamido group have been developed. The novel compounds were characterized
at melatonin receptors MT1R and MT2R, quinone reductase 2 (QR2), lipoxygenase-5 (LOX-5), and
monoamine oxidases (MAO-A and MAO-B), and also as radical scavengers. We found that selectivity
within the oxadiazolone series can be modulated by modifying the side chain functionality and coplanarity
with the indole or naphthalene ring. In phenotypic assays, several oxadiazolone-based derivatives
induced signalling mediated by the transcription factor NRF2 and promoted the maturation of
neural stem-cells into a neuronal phenotype. Activation of NRF2 could be due to the binding of indole
derivatives to KEAP1, as deduced from surface plasmon resonance (SPR) experiments. Molecular
modelling studies using the crystal structures of QR2 and the KEAP1 Kelch-domain, as well as the recently described X-ray free-electron laser (XFEL) structures of chimeric MT1R and MT2R, provided a
rationale for the experimental data and afforded valuable insights for future drug design endeavoursThe authors gratefully acknowledge the following financial
supports: Spanish Ministry of Science, Innovation and Universities;
Spanish Research Agency; and European Regional Development
Funds (grants RTI2018-093955-B-C21 and SAF2015-64948-C2-1-R
to M.I.R.-F.; RTI2018-095793-B-I00 to M.G.L., SAF2015-64629-C2-
2-R to F.G.), General Council for Research and Innovation of the
Community of Madrid and European Structural Funds (grant
B2017/BMD-3827 e NRF24ADCM), Health Institute Carlos III
(Miguel Servet II ProgramCP16/00014 and grant PI17/01700 to R.L.).
CH-A and P.M. thank their PhD fellowships from Spanish Ministry
of Education (MEC, PhD grant FPU16/01704 and mobility grant
FPUEST17/00233 to CH-A and FPU13/03737 to P.M.)
Targeting aberrant DNA methylation in mesenchymal stromal cells as a treatment for myeloma bone disease
Multiple myeloma (MM) progression and myeloma-associated bone disease (MBD) are highly dependent on bone marrow mesenchymal stromal cells (MSCs). MM-MSCs exhibit abnormal transcriptomes, suggesting the involvement of epigenetic mechanisms governing their tumor-promoting functions and prolonged osteoblast suppression. Here, we identify widespread DNA methylation alterations of bone marrow-isolated MSCs from distinct MM stages, particularly in Homeobox genes involved in osteogenic differentiation that associate with their aberrant expression. Moreover, these DNA methylation changes are recapitulated in vitro by exposing MSCs from healthy individuals to MM cells. Pharmacological targeting of DNMTs and G9a with dual inhibitor CM-272 reverts the expression of hypermethylated osteogenic regulators and promotes osteoblast differentiation of myeloma MSCs. Most importantly, CM-272 treatment prevents tumor-associated bone loss and reduces tumor burden in a murine myeloma model. Our results demonstrate that epigenetic aberrancies mediate the impairment of bone formation in MM, and its targeting by CM-272 is able to reverse MBD. Mesenchymal stromal cells (MSCs) have been shown to support multiple myeloma (MM) development. Here, MSCs isolated from the bone marrow of MM patients are shown to have altered DNA methylation patterns and a methyltransferase inhibitor reverts MM-associated bone loss and reduces tumour burden in MM murine models
Adaptación al bilingüismo del material docente de prácticas de Zoología
El objetivo principal de este proyecto de innovación docente es la adaptación al bilingüismo, concretamente al inglés, del material de prácticas (presenciales y virtuales) de la asignatura de Zoología del grado de Biología. Este objetivo se enmarca dentro del actual proceso de internacionalización de la UGR, que en el caso concreto del grado de Biología se ha iniciado el curso académico 2021/2022 con algunas asignaturas impartidas en inglés. Aunque el bilingüismo en la asignatura de Zoología se ha retrasado hasta el curso 2022/2023.Universidad de Granad
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