De la viñeta a la cámara

Análisis sobre algunas de las producciones cinematográficas recientes que se han inspirado en series de cómic o que son cercanas al lenguaje o las estéticas utilizados en el medio

The Beauty of Symmetry: Common-mode rejection filters for high-speed interconnects and balanced microwave circuits

Common-mode rejection filters operating at microwave frequencies have been the subject of intensive research activity in the last decade. These filters are of interest for the suppression of common-mode noise in high-speed digital circuits, where differential signals are widely employed due to the high immunity to noise, electromagnetic interference (EMI) and crosstalk of differential-mode interconnects. These filters can also be used to improve common-mode rejection in microwave filters and circuits dealing with differential signals. Ideally, common-mode stopband filters should be transparent for the differential mode from DC up to very high frequencies (all-pass), should preserve the signal integrity for such mode, and should exhibit the widest and deepest possible rejection band for the common mode in the region of interest. Moreover, these characteristics should be achieved by means of structures with the smallest possible size. In this article, several techniques for the implementation of common-mode suppression filters in planar technology are reviewed. In all the cases, the strategy to simultaneously achieve common-mode suppression and all-pass behavior for the differential mode is based on selective mode-suppression. This selective mode suppression (either the common or the differential mode) in balanced lines is typically (although not exclusively) achieved by symmetrically loading the lines with symmetric resonant elements, opaque for the common-mode and transparent for the differential mode (common-mode suppression), or vice versa (differential-mode suppression).MINECO, Spain-TEC2013-40600-R, TEC2013-41913-PGeneralitat de Catalunya-2014SGR-15

Study of calcium sparks and calcium wave propagation in cardiac cells

Contraction of cardiac cells is initiated by an increase in the level of intracellular calcium concentration. The calcium response is the combination of the local stochastic release of tens of thousands of release sites. The possible responses range from sparks (local release) to a global calcium increase, passing from calcium waves that propagate along the cell. In this project we model the intracellular calcium dynamics as a network of excitable elements that fire stochastically, and study the occurrence of calcium waves and spark nucleation. In an initial part, we model the sparks of a homogeneous distribution of calcium nodes. We study the wave propagation of this model depending on properties accounting for the state of the heart. We develop a simplified mean-field theory which will shed light on various aspects of the dynamics of the model. In a second part, we proceed to add clustering onto our model, and with it, we study its new wave propagation and the dynamics of the model

A hybridizable discontinuous Galerkin phase-field model for brittle fracture

Phase-field models for brittle fracture consider smeared representations of cracks, which are described by a continuous field that varies abruptly in the transition zone between unbroken and broken states. Computationally, meshes have to be fine locally near the crack to capture the solution. We present an HDG formulation for a quasi-static phase-field model, based on a staggered approach to solve the system. The use of HDG for this model is motivated by the suitability of the method for spatial adaptivity.Peer ReviewedPostprint (author's final draft

Palladium-catalysed intramolecular carbenoid insertion of α-diazo α-(methoxycarbonyl)acetanilides for oxindole synthesis

A novel, selective palladium-catalysed carbenoid C(aryl)-H insertion of α-diazo-α-(methoxycarbonyl)acetanilides leading to oxindoles is described

A hybridizable discontinuous Galerkin phase-field model for brittle fracture with adaptive refinement

This is the peer reviewed version of the following article: Muixi, A.; Rodriguez-Ferran, A.; Fernandez, S. A hybridizable discontinuous Galerkin phase-field model for brittle fracture with adaptive refinement. "International journal for numerical methods in engineering", 30 Març 2020, vol. 121, núm. 6, p. 1147-1169, which has been published in final form at DOI: 10.1002/nme.6260. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.In this paper, we propose an adaptive refinement strategy for phase-field models of brittle fracture, which is based on a novel hybridizable discontinuous Galerkin (HDG) formulation of the problem. The adaptive procedure considers standard elements and only one type of h-refined elements, dynamically located along the propagating cracks. Thanks to the weak imposition of interelement continuity in HDG methods, and in contrast with other existing adaptive approaches, hanging nodes or special transition elements are not needed, which simplifies the implementation. Various numerical experiments, including one branching test, show the accuracy, robustness, and applicability of the presented approach to quasistatic phase-field simulations.Peer ReviewedPostprint (author's final draft

Adaptive refinement for phase-field models of brittle fracture based on Nitsche's method

“This is a post-peer-review, pre-copyedit version of an article published in Computational mechanics. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00466-020-01841-1”.A new adaptive refinement strategy for phase-field models of brittle fracture is proposed. The approach provides a computationally efficient solution to the high demand in spatial resolution of phase-field models. The strategy is based on considering two types of elements: h-refined elements along cracks, where more accuracy is needed to capture the solution, and standard elements in the rest of the domain. Continuity between adjacent elements of different type is imposed in weak form by means of Nitsche's method. The weakly imposition of continuity leads to a very local refinement in a simple way, for any degree of approximation and both in 2D and 3D. The performance of the strategy is assessed for several scenarios in the quasi-static regime, including coalescence and branching of cracks in 2D and a twisting crack in 3D.Peer ReviewedPostprint (author's final draft

Bioengineered in vitro skeletal muscles as new tools for muscular dystrophies preclinical studies

Muscular dystrophies are a group of highly disabling disorders that share degenerative muscle weakness and wasting as common symptoms. To date, there is not an effective cure for these diseases. In the last years, bioengineered tissues have emerged as powerful tools for preclinical studies. In this review, we summarize the recent technological advances in skeletal muscle tissue engineering. We identify several ground-breaking techniques to fabricate in vitro bioartificial muscles. Accumulating evidence shows that scaffold-based tissue engineering provides topographical cues that enhance the viability and maturation of skeletal muscle. Functional bioartificial muscles have been developed using human myoblasts. These tissues accurately responded to electrical and biological stimulation. Moreover, advanced drug screening tools can be fabricated integrating these tissues in electrical stimulation platforms. However, more work introducing patient-derived cells and integrating these tissues in microdevices is needed to promote the clinical translation of bioengineered skeletal muscle as preclinical tools for muscular dystrophies

Multi-temporal evaluation of soil moisture and land surface temperature dynamics using in situ and satellite observations

Soil moisture (SM) is an important component of the Earth’s surface water balance and by extension the energy balance, regulating the land surface temperature (LST) and evapotranspiration (ET). Nowadays, there are two missions dedicated to monitoring the Earth’s surface SM using L-band radiometers: ESA’s Soil Moisture and Ocean Salinity (SMOS) and NASA’s Soil Moisture Active Passive (SMAP). LST is remotely sensed using thermal infrared (TIR) sensors on-board satellites, such as NASA’s Terra/Aqua MODIS or ESA & EUMETSAT’s MSG SEVIRI. This study provides an assessment of SM and LST dynamics at daily and seasonal scales, using 4 years (2011–2014) of in situ and satellite observations over the central part of the river Duero basin in Spain. Specifically, the agreement of instantaneous SM with a variety of LST-derived parameters is analyzed to better understand the fundamental link of the SM–LST relationship through ET and thermal inertia. Ground-based SM and LST measurements from the REMEDHUS network are compared to SMOS SM and MODIS LST spaceborne observations. ET is obtained from the HidroMORE regional hydrological model. At the daily scale, a strong anticorrelation is observed between in situ SM and maximum LST (R ˜ -0.6 to -0.8), and between SMOS SM and MODIS LST Terra/Aqua day (R ˜ - 0.7). At the seasonal scale, results show a stronger anticorrelation in autumn, spring and summer (in situ R ˜ -0.5 to -0.7; satellite R ˜ -0.4 to -0.7) indicating SM–LST coupling, than in winter (in situ R ˜ +0.3; satellite R ˜ -0.3) indicating SM–LST decoupling. These different behaviors evidence changes from water-limited to energy-limited moisture flux across seasons, which are confirmed by the observed ET evolution. In water-limited periods, SM is extracted from the soil through ET until critical SM is reached. A method to estimate the soil critical SM is proposed. For REMEDHUS, the critical SM is estimated to be ~0.12 m3/m3 , stable over the study period and consistent between in situ and satellite observations. A better understanding of the SM–LST link could not only help improving the representation of LST in current hydrological and climate prediction models, but also refining SM retrieval or microwave-optical disaggregation algorithms, related to ET and vegetation status.Peer ReviewedPostprint (published version