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Curso 2022-2023, Optativa 3º curso, Cuatrimestral, 6 créditos

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Surface reconstituted metal-organic frameworks (MOFs) offer appealing properties for electrocatalysis due to their unique structural and compositional advantages. In this work, a controlled potential-induced reconstruction of a two-dimensional cobalt metal-organic framework for boosting oxygen evolution reaction in alkaline media is reported. The current MOF is shown to undergo a partial structural transformation that generates a heterogeneous system, where the original MOF coexists with an oxyhydroxide phase. In fact, the potential-induced stabilization of Co(III) metal centers in the MOF is crucial for delaying its full degradation in alkaline media. This partial retention of the Co(III)MOF phase in the so-derived heterogeneous catalyst has been demonstrated to be decisive for boosting the alkaline electrocatalytic oxygen evolution reaction (OER), displaying superior OER activity in terms of both thermodynamic and kinetic merits compared to the benchmark IrO2 and RuO2 electrocatalysts and the prototypical cobalt (oxy)hydroxides, with a Tafel slope of 52 mV dec−1 and a turnover frequency (TOF) of 6.8 s−1 at 450 mV. Remarkably, the generated final product is stable, exhibiting high robustness and long durability for long-term OER electrolysis. This work provides new insight into the impact of the reconstruction of a MOF for alkaline OER under typical electrochemical conditions, which ultimately benefits the rational design of MOF-based catalysts with high electrocatalytic activity for oxidation reactions.

170 p., La presente tesis se centra en el estudio y escalado de una tecnología disruptiva denominada "limpieza por ultrasonidos sin inmersión". La limpieza ultrasónica convencional se basa en la introducción de componentes sucios en un baño líquido, al cual, se le aplica ultrasonido de alta intensidad que desprende las partículas. La necesidad de sumergir el componente en un recipiente supone una desventaja diferencial frente a otros procedimientos como el cepillado y los chorros de agua a presión. El estudio parte de la hipótesis de poder aplicar los mismos principios de limpieza sin necesidad de sumergir el objeto en cuestión. Para ello, se plantea y se demuestra el concepto aplicar el ultrasonido a través de un puente capilar sustentado entre el emisor de ultrasonido (sonotrodo) y la superficie a limpiar. El puente capilar se barre a lo largo de la superficie, dando lugar a un novedoso proceso de limpieza. De ahí la motivación y principal objetivo del trabajo realizado: estudiar y comprender los fenómenos fisicoquímicos que intervienen durante la limpieza por ultrasonidos sin inmersión. Para ello, se han combinado modelos analíticos, experimentación a escala de laboratorio y escalado de la tecnología para la limpieza de componentes de concentración solar, donde el grado de limpieza impacta directamente sobre la producción energética. El principal resultado del estudio teórico es el planteamiento, modelizado termodinámico y validación de un mecanismo de no-retorno por el cual, los sistemas de tres fases aumentan su mojabilidad mecánicamente al inducirles vibración de alta frecuencia. Dicho aumento de mojabilidad es la clave a la hora de generar un puente capilar estable entre el sonotrodo y el sustrato. Tanto analíticamente como experimentalmente, se ha podido concluir que la eficiencia energética del sonido a la hora de aumentar la mojabilidad entre fases es similar a la del SDBS, siendo a su vez 8 órdenes de magnitud superior al calor. A su vez, se ha estudiado la siner

221 p., Wnt-11 es una proteína que se encuentra altamente expresada en el cáncer de próstata metastático, donde favorece la diferenciación neuroendocrina, la supervivencia y la migración celular activando señales a través de la familia de factores de transcripción AP-1/ATF, independientes de ß-catenina. Para caracterizar los efectos de la inhibición selectiva de Wnt-11, se generaron dos anticuerpos monoclonales anti-Wnt-11, E8 y F10, que tienen el mismo epítopo en Wnt-11. Los anticuerpos reconocen Wnt-11 en contexto celular, reducen la fosforilación del efector de Wnt DVL, reducen la proliferación en esferas de células de cáncer de próstata, inhiben la migración e invasión celular y la migración de células en hipoxia. Se llevó a cabo la conjugación de E8 y F10 a nanopartículas magnéticas (MNP) y se determinó que las nanoformulaciones anti-Wnt-11 inhiben la migración celular sin afectar a la viabilidad. Tanto E8 como la nanoformulación MNP-E8 reducen el crecimiento tumoral de células PC3 en el modelo in vivo de la membrana corioalantoidea de pollo, CAM. Se caracterizó un mutante de Wnt-11 con el epítopo de los anticuerpos delecionado, y se determinó que esta región tiene un papel relevante en la función y señalización de Wnt-11. La deleción del epítopo limita la migración celular inducida por Wnt-11, reduce la fosforilación de DVL, inhibe la transcripción dependiente de ATF2 y produce una disminución en la interacción de Wnt-11 con un correceptor de Wnt. En conjunto, los resultados resaltan el papel de Wnt-11 como una posible diana terapéutica y los anticuerpos anti-Wnt-11 y sus nanoformulaciones como potenciales agentes terapéuticos para el tratamiento del cáncer de próstata metastático.

298 p., Las aleaciones con memoria de forma son conocidas como SMA por sus siglas en inglés (Shape Memory Alloys) y se caracterizan por tener una transformación martensítica con dos propiedades principales: memoria de forma y efecto superelástico.En la memoria de forma, un objeto en su fase martensita de baja temperatura puede ser deformado fácilmente. Cuando el material se calienta y se forma la fase austenita, esta revierte todas las deformaciones que se habían inducido sobre la martensita. Por otra parte, en el efecto superelástico, los materiales en la fase austenita de alta temperatura pueden ser sometidos a deformaciones muy elevadas que se recuperan totalmente a lretirar las tensiones aplicadas. Estas dos propiedades pueden aprovecharse activamente para generar una fuerza (con la memoria de forma) o para almacenar energía (con el efecto superelástico), lo que convierte a las SMA en materiales inteligentes.A la vista de la gran variedad de las aplicaciones de las SMA, se ha realizado un trabajo en el que se exploran diferentes campos relacionados con este tipo de aleaciones inteligentes:- Las SMA del sistema Cu-Al-Ni han demostrado tener unas muy buenas propiedades. Aunque son aleaciones frágiles en su estado policristalino, alcanzan valores muy elevados de deformación superelástica en estado monocristalino. En este trabajo, se han diseñado, elaborado y caracterizado (tanto la microestructura como las propiedades termomecánicas) SMA cuaternarias monocristalinas para aplicaciones a media y baja temperatura basadas en el sistema del Cu-Al-Ni, al que se le ha añadido un cuarto elemento: Ga, Be, Au o Mn.- Las SMA del sistema binario Ni-Ti son la aleación más utilizada comercialmente, pero por lo general para aplicaciones a temperaturas inferiores a los100 ºC. Por lo tanto, existe un interés por el desarrollo de nuevas aleaciones basadas en el sistema Ni-Ti para aplicaciones a alta temperatura, como es la aleación Ni-Ti-Hf. Se han caracterizado SMA de alta temperatura de N

268 p., Los factores de transcripción E2F son cruciales en la regulación de genes involucrados en la progresión del ciclo celular, la replicación del ADN, la reparación de daño al ADN o la duplicación de los orgánulos. En este trabajo se realizó un análisis bioinformático con el fin de encontrar nuevos genes diana de los E2F que pudieran estar asociados al ciclo celular y al cáncer. En dicho análisis se identificó a TEDC2 (Tubulin Epsilon and Delta Complex 2), proteína centriolar poco caracterizada, como potencial diana de los E2F. Observamos que las muestras tumorales con una elevación de los niveles de TEDC2 se correlacionaban con un peor pronóstico. El gen TEDC2 se co-expresa y presenta codependencia con otros genes que participan en la duplicación centriolar y en mitosis. Demostramos que la expresión de TEDC2 está regulada durante el ciclo celular con un máximo en la entrada de fase S, momento en el que E2F1 se une al promotor de TEDC2, activando su transcripción. Respecto a su localización subcelular, TEDC2 se localiza en el material pericentriolar y en el anillo del midbody, para lo que requiere dos dominios de localización. TEDC2 interacciona con proteínas del ciclo del centrosoma, destacando a CEP295 y a las tres proteínas con las que forma el complejo TED: TEDC1 y las tubulinas ¿ y ¿. Predicciones de la estructura del complejo TED sugieren que TEDC1 ejerce de puente entre el heterodímero de las tubulinas ¿ /¿ y TEDC2. Por último, experimentos de silenciamiento mostraron que TEDC2 es indispensable para la correcta duplicación de los centriolos y la función del centrosoma

222 p., Las células natural killer (NK) son un componente clave del Sistema Inmunitario y juegan un papel fundamental en la defensa frente a infecciones virales y células cancerígenas. Una breve estimulación con interleuquina (IL)-12, IL-15 e IL-18 confiere a las células NK unas propiedades similares a las de la memoria inmunológica. Estas células NK con propiedades tipo memoria son conocidas como cytokine-induced memory-like (CIML) tienen una actividad antitumoral superior y han demostrado ser capaces de combatir eficazmente diferentes cánceres en modelos de ratón. Además, las células NK CIML se están probando en 10 ensayos clínicos y están mostrando resultados muy prometedores. Dada la relevancia terapéutica de estas células NK estimuladas con IL-12/15/18, el objetivo de esta tesis es estudiar el efecto de estas IL sobre diferentes aspectos de las células NK, incluyendo el fenotipo, funciones efectoras, metabolismo y la dinámica mitocondrial. Nuestros datos han mostrado cómo la estimulación con IL-12/15/18 incrementa la capacidad citotóxica y la polifuncionalidad de las células NK, y les confiere la capacidad de proliferar en respuesta a dosis bajas de IL-2. También describimos cómo la estimulación con IL-12/15/18 induce una reprogramación metabólica de las células NK, y la relevancia de algunas rutas metabólicas para las funciones efectoras de estas células. Por último, estudiamos los cambios que induce la estimulación con IL-12/15/18 sobre las mitocondrias de las células NK y la relación que tienen con su viabilidad.

164 p., Las mutaciones sin sentido generan codones de terminación prematura (PTC) y son alteraciones genéticas frecuentes en cáncer y en enfermedad. Las proteoformas que surgen de estas variantes de PTC suelen ser menos estables y muestran una función proteica disminuida. En esta tesis doctoral, se ha estudiado in silico la distribución de PTC asociada a cáncer y la influencia del reinicio de traducción mediado por mutaciones sin sentido en genes supresores tumorales de forma global. Hemos descrito y caracterizado a nivel molecular una nueva proteoforma de PTEN derivada del reinicio de traducción a partir de la Met35 que hemos designado PTEN M35. Igualmente, hemos descubierto que la isoforma corta de VHL pVHL19 se genera a través del reinicio de traducción mediado por mutaciones sin sentido en la Met54. Además, esta tesis a demostrado que el reinicio de traducción mediado por mutaciones sin sentido tiene lugar en MMADHC en la Met62 y la Met116. Por último, para variantes de los tres genes estudiados con mutaciones PTC, se ha realizado un estudio de reconstitución de la biosíntesis de la proteína mediante readthrough (lectura a través) traduccional, utilizando principalmente el aminoglucósido geneticina (G418) como inductor. Los resultados de esta tesis indican que PTC en PTEN, VHL y MMADHC son susceptibles a reconstitución mediante readthrough, y que dicha reconstitución depende de la naturaleza del PTC, el contexto nucleotídico y la expresión basal de la proteína.

270 p., Los análisis moleculares, tanto de genética como de microbiota intestinal, pueden ser herramientas de medición imprecisas por sí solas pero muy importantes en la determinación del perfil fisiológico individual de los deportistas. Pese a que la investigación actual en biología molecular aplicada al deporte es extensa, no encontramos una aplicación práctica diaria que sea válida en su aplicación para deportistas y entrenadores. Por ello, el presente trabajo determina como el aporte de datos desde los análisis moleculares al conjunto de valoraciones específicas de rendimiento puede contribuir importantemente a la determinación de la funcionalidad fenotípica de los deportistas. Conocer las posibles tendencias innatas asociadas al rendimiento físico a través del análisis genético puede ayudarnos a detectar particularidades individuales y mejorar los modelos de entrenamiento basados en la individualidad. Además, podemos especular como la capacidad adaptativa individual ante estímulos concretos influye en el rendimiento final deportivo. Por ejemplo, como la falta de una característica genética determinante para el desarrollo de un fenotipo puede ser sustituida con el desarrollo de otra particularidad fisiológica adaptativa. La capacidad plástica de la microbiota intestinal y su gran influencia en la salud y el desarrollo fisiológico nos aportan una gran capacidad de poder influir en el estado del deportista. Por ello, la detección y categorización de fenotipos de rendimiento asociados a la microbiota intestinal puede ser un objetivo a desarrollar en los siguientes años de investigación. De este modo, poder mejorar las herramientas de análisis molecular puede favorecer directamente la prevención de lesiones y mejorar el estado perceptivo frente a limitantes en la progresión del rendimiento en deportistas. La individualización del entrenamiento y la valoración del deportista desde la perspectiva molecular y fisiológica debe ser el futuro de la investigación y la aplicación p

225 p., Aging is associated with a series of phenotypic changes at the cellular level, including changes in gene expression. In recent years, aged tissues have been reported to present an increase in transcriptional noise or cell-to-cell variability. In order to test this, a new method (Scallop) for the quantification of transcriptional noise from single-cell RNA sequencing (scRNA-seq) data has been developed, which is based on cluster membership. In addition, a compilation of methods used in the literature has been implemented in the Python toolkit Decibel. A systematic analysis of published scRNA-seq datasets of murine and human aged tissues using Scallop and Decibel revealed that increased transcriptional noise is not a universal hallmark of aging. A deeper analysis of four scRNA-seq datasets of the murine aging lung showed that, even though there are no consistent cell type-specific changes in transcriptional noise levels, the aging lung is characterized by a reproducible enrichment in immune cell types, which was also seen in two human datasets. Interestingly, an exploratory analysis of gene expression datasets of murine and human aging revealed a previously undetected hallmark of aging: aged tissues present a generalized length-dependent transcriptional decay. This length-dependent underexpression (LDU) was also observed in premature aging models caused by exposure to environmental genotoxicity (UV radiation and tobacco smoke) and in two progeroid syndromes caused by defects in the transcription-coupled nucleotide excision repair pathway (TC-NER): Cockayne syndrome and trichothiodystrophy. These results suggest that accumulation of genotoxicity in long genes could lead to reduced RNA polymerase II procesivity.

Low-toxicity solar concentrator systems represent an important challenge for outstanding photovoltaic (PV) applications. Particularly, multiplexed holographic lenses (MHL) as Holographic Solar Concentrators (HSC) provide insight into promising possibilities for Building-Integrated Concentrating PVs. This technology does not affect crucial ecosystems, and can convert buildings from energy consumers into energy suppliers. They can be used in windows, roofs, or walls, and a high diffraction efficiency and wide acceptance angle are desired. In this work, we presented several designs of MHL of low spatial frequency 525 lines mm−1, based on a low-toxicity photopolymer and supported on a window glass. The average diffraction efficiency of these HSC was evaluated at 633 nm, whereas the acceptance angle was evaluated by measuring the short-circuit current under solar illumination at different incident angles. Versatile and high-efficiency holographic elements have been used to concentrate sunlight from different relative positions during the day, avoiding the need for expensive tracking systems. To the best of our knowledge, this is the best trade-off between high diffraction efficiency (85%) and wide acceptance angle (104∘) in a low-toxicity holographic solar concentrator.

The Double Asteroid Redirection Test (DART) had an impact with Dimorphos (a satellite of the asteroid Didymos) on 26 September 20221. Ground-based observations showed that the Didymos system brightened by a factor of 8.3 after the impact because of ejecta, returning to the pre-impact brightness 23.7 days afterwards2. Hubble Space Telescope observations made from 15 minutes after impact to 18.5 days after, with a spatial resolution of 2.1 kilometres per pixel, showed a complex evolution of the ejecta3, consistent with other asteroid impact events. The momentum enhancement factor, determined using the measured binary period change4, ranges between 2.2 and 4.9, depending on the assumptions about the mass and density of Dimorphos5. Here we report observations from the LUKE and LEIA instruments on the LICIACube cube satellite, which was deployed 15 days in advance of the impact of DART. Data were taken from 71 seconds before the impact until 320 seconds afterwards. The ejecta plume was a cone with an aperture angle of 140 ± 4 degrees. The inner region of the plume was blue, becoming redder with increasing distance from Dimorphos. The ejecta plume exhibited a complex and inhomogeneous structure, characterized by filaments, dust grains and single or clustered boulders. The ejecta velocities ranged from a few tens of metres per second to about 500 metres per second.

On 2022 September 26 23:14 UT, the NASA Double Asteroid Redirection Test spacecraft successfully impacted Dimorphos, the secondary component of the binary (65803) Didymos system, demonstrating asteroid orbit deflection for the first time. A large amount of debris, consisting of a wide size–frequency distribution of particulates (from micron-sized dust to meter-sized boulders), was released, and a long-lasting tail has been observed over more than 9 months since impact. An important fraction of the ejecta mass has been ejected as individual meter-sized boulders, as have been found in images obtained by the Light Italian CubeSat for Imaging of Asteroid (LICIACube), as well as from the Hubble Space Telescope (HST). While the boulders observed by LICIACube had projected speeds of several tens of m s–1, those seen by the HST were about 100 times slower. In this paper, we analyze the long-term orbital evolution of those slow boulders using different dynamical codes, providing constraints on the fate of such large particles, and giving insight on the possibility of observing some of those boulders that might remain in orbit at the time of the ESA/Hera mission arrival to the binary system in late 2026.

The Casimir-Lifshitz force, FC − L, has become a subject of great interest to both theoretical and applied physics communities due to its fundamental properties and potential technological implications in emerging nano-scale devices. Recent cutting-edge experiments have demonstrated the potential of quantum trapping at the nano-scale assisted by FC − L in metallic planar plates immersed in fluids through appropriate stratification of the inner dielectric media, opening up new avenues for exploring physics at the nano-scale. This review article provides an overview of the latest results in Casimir-Lifshitz based-optical resonator schemes and their potential applications in fields such as microfluidic devices, bio-nano and micro electromechanical systems (NEMS and MEMS), strong coupling, polaritonic chemistry, photo-chemistry, sensing, and metrology. The use of these optical resonators provides a versatile platform for fundamental studies and technological applications at the nano-scale, with the potential to revolutionize various fields and create new opportunities for research.

The determination of the solubility of helium in liquid lithium and in lead-lithium eutectic systems is of crucial importance for the assessment of the reliability, safety and efficiency of future nuclear reactor plants based on fusion technology. In this way, an important aspect to be considered concerns the possibility of accumulations of gas inside the so called breeding blankets of the reactors, due to the low solubility of helium, leading to potentially undesired effects. In the present work we have performed molecular dynamics simulations in order to examine the characteristics of the solubility of helium in alkali metals along a temperature interval that covers near ambient conditions up to temperatures of the order of a 1000 K. Our methodology relied on the classical Kirkwood perturbative approach, which involves the gradual coupling between the infinite diluted He atom and the solvent. Such insertion proceeds along three stages that involved a previous incorporation of a softly interacting cavity that prevented singularities due to the harshly repulsive nature of the actual He-Li potential. Simulated structure factors predicted by the force fields of the different alkali metals were found to be in excellent agreement with available experimental information. Moreover, at all thermal conditions, our results of Henry's constants predict a steady volatility reduction with increasing temperatures, in good agreement with available experimental data. Furthermore, Henry's law volatility constants increase as the sizes of the atoms of the host alkali metals become more comparable to the size of the He atom (the predicted solubility increases with the size of the alkali atoms), and are coherent with the scarce experimental data available., The authors thank L.A. Sedano and A. Awad for fruitful discussions. J.M. and L.B. acknowledge financial support from the Generalitat de Catalunya (project “FusionCAT”, number J-02603) and from the EUROfusion project (HORIZON-101052200-EUROfusion). J.M. and E.A-G. thank financial support of project PID2021-124297NB-C32 funded by Ministerio de Ciencia e Innovación MCIN/AEI/10.13039/5011000-11033 “A way of making Europe” by the “European Union NextGenerationEU/PRTR”. J.M. gratefully acknowledges financial support from the Generalitat de Catalunya (Grant 2021 SGR 01411). E.A-G. has been awarded a fellowship at the Polytechnic University of Catalonia by the Spanish “Consejo de Seguridad Nuclear” through the ARGOS Chair of Nuclear Safety and Radiation Protection., Peer Reviewed, Postprint (published version)

The slow transition from an out-of-equilibrium glass towards a supercooled liquid is a complex relaxation phenomenon. In this Letter, we study the correlation between mechanical relaxation and equilibration kinetics in a Pd20Pt20Cu20Ni20P20 high-entropy metallic glass. The evolution of stress relaxation with aging time was obtained with an unprecedented detail, allowing us to pinpoint new interesting features. The long structural relaxation towards equilibrium contains a wide distribution of activation energies, instead of being just associated to the ß relaxation as commonly accepted. The stress relaxation time can be correlated with the equilibration rate and we observe a decrease of microstructural heterogeneity which contrasts with an increase of dynamic heterogeneity. These results significantly enhance our insight of the interplay between relaxation dynamics and thermodynamics in metallic glasses., Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant, Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.a - Per a 2030, augmentar la cooperació internacional per tal de facilitar l’accés a la investigació i a les tecnolo­gies energètiques no contaminants, incloses les fonts d’energia renovables, l’eficiència energètica i les tecnologies de combustibles fòssils avançades i menys contaminants, i promoure la inversió en infraestructures energètiques i tecnologies d’energia no contaminant, Postprint (author's final draft)

Introduction: We use Spanish data from August 2020 to March 2021 as a natural experiment to analyze how a standardized measure of COVID-19 growth correlates with asymmetric meteorological and mobility situations in 48 Spanish provinces. The period of time is selected prior to vaccination so that the level of susceptibility was high, and during geographically asymmetric implementation of non-pharmacological interventions. Methods: We develop reliable aggregated mobility data from different public sources and also compute the average meteorological time series of temperature, dew point, and UV radiance in each Spanish province from satellite data. We perform a dimensionality reduction of the data using principal component analysis and investigate univariate and multivariate correlations of mobility and meteorological data with COVID-19 growth. Results: We find significant, but generally weak, univariate correlations for weekday aggregated mobility in some, but not all, provinces. On the other hand, principal component analysis shows that the different mobility time series can be properly reduced to three time series. A multivariate time-lagged canonical correlation analysis of the COVID-19 growth rate with these three time series reveals a highly significant correlation, with a median R-squared of 0.65. The univariate correlation between meteorological data and COVID-19 growth is generally not significant, but adding its two main principal components to the mobility multivariate analysis increases correlations significantly, reaching correlation coefficients between 0.6 and 0.98 in all provinces with a median R- squared of 0.85. This result is robust to different approaches in the reduction of dimensionality of the data series. Discussion: Our results suggest an important effect of mobility on COVID- 19 cases growth rate. This effect is generally not observed for meteorological variables, although in some Spanish provinces it can become relevant. The correlation betwe, The author(s) declare financial support was received for the research, authorship, and/or publication of this article. We acknowledge BBVA Foundation for funding through the project EMoSP in the call “Ayudas fundación BBVA a proyectos de investigacion cientifica 2021,” as well as Generalitat de Catalunya, through grant 2021-SGR-00582. AT was supported by the Spanish National Research project (ref. PID2020-119072RAI00/AEI/10.13039/501100011033) funded by the Spanish Ministry of Science, Innovation, and Universities (MCIU). DC acknowledges the FI-SDUR program from the Departament de Recerca i Universitats de la Generalitat de Catalunya through grant 2020-FISDU-00511., Peer Reviewed, Postprint (published version)

Due to the disordered structure of amorphous alloys, the complex structural dynamics involves the particle rearrangements with a large span in time and size scales. The characterization and mechanism of structural dynamics of amorphous alloys are crucial and fundamental for the further research of relaxation behavior and physical aging kinetics of glasses. Abundant researches show that the relaxation spectra of rare-earth-based amorphous alloys, which are represented by lanthanum- and cerium-based alloys, show obvious secondary relaxation process, and the system becomes an ideal carrier to investigate the relationship between structural dynamics and mechanical properties of amorphous alloys. In this review, the anelasticity of metallic glasses was discussed. The anelastic deformation, as the main component of deformation, can totally recovery after unloading in creep experiments, and its mechanism is important to form deep understanding about the structural dynamics of metallic glasses. Additionally, the main characteristics of anelastic deformation during creep and creep recovery were summarized, and some theoretical models for quantitative and qualitative description were introduced., Postprint (author's final draft)

In this work we propose new structure-preserving multiple time stepping methods for numerical simulation of charge transfer by intrinsic localized modes in nonlinear crystal lattice models. We consider, without loss of generality, one-dimensional crystal lattice models described by classical Hamiltonian dynamics, whereas charge (electron or hole) is modeled as a quantum particle within the tight-binding approximation. Proposed multiple time stepping schemes are based on symplecticity-preserving symmetric splitting methods recently developed by the authors. Originally developed explicit splitting methods do not exactly conserve total charge probability, thus, to improve charge probability conservation and to better resolve high frequency oscillations of the charge in numerical simulations with large time steps we incorporate multiple time stepping approach when solving split charge equations. Improved numerical results with multiple time stepping methods of charge transfer by mobile discrete breathers are demonstrated in a crystal lattice model example.

A research model to simulate the propagation of tsunamis caused by different mechanisms was developed in this paper. These mechanisms are submarine earthquakes, landslides and collapse of volcano calderas. The model is based upon the non-linear shallow-water hydrodynamic equations with horizontal viscosity and friction with the seabed. It also includes a flooding/drying algorithm. This model was tested by applying it to several past tsunamis and comparisons of results with available data and/or other models. The objective of this paper is to present a summary on the application of the model to historical tsunamis occurred in European waters: Atlantic Ocean, Mediterranean Sea and Caspian Sea. Additionally, two application examples on how the research model can be used to confront different candidate tsunami sources and to discard scenarios of catastrophic floodings initially attributed to tsunamis presented: the Santorini tsunami sequence and the flooding of the Gulf of Tartessos in SW Spain.

Background This study aims to identify sports interventions for children and adolescents (CaA) with chronic diseases and evaluate their impact on physical, psychological, and social well‑being. The findings of this study will contribute to our understanding of the potential benefits of sports interventions for CaA with chronic diseases and inform future interventions to promote their overall health and well‑being. Methods A systematic review was conducted in eight databases. This systematic review followed PRISMA guidelines and utilized a comprehensive search strategy to identify studies on sport‑based interventions for CaA with chronic diseases. The review included randomized controlled trials and observational studies that focused on physical and psychosocial outcomes. Results We screened 10,123 titles and abstracts, reviewed the full text of 622 records, and included 52 primary stud ies. A total of 2352 participants were assessed with an average of 45 ± 37 participants per study. Among the included studies involving CaA with chronic diseases with an age range from 3 to 18 years, 30% (n = 15) autism spectrum dis orders, 21% (n = 11) cerebral palsy, 19% (n = 10) were attention deficit hyperactivity disorder, and 17% (n = 9) obesity. Other diseases included were cancer (n = 5), asthma (n = 1) and cystic fibrosis (n = 1). Interventions involved various sports and physical activities tailored to each chronic disease. The duration and frequency of interventions varied across studies. Most studies assessed physical outcomes, including motor performance and physical fitness measures. Psychosocial outcomes were also evaluated, focusing on behavioural problems, social competencies, and health related quality of life. Conclusion Overall, sport‑based interventions effectively improved physical and psychosocial outcomes in CaA with chronic diseases. Interventions are generally safe, and participants adhere to the prescribed protocols favorably. Despite that, there is little e

Spacecraft observations revealed that rocks on carbonaceous asteroids, which constitute the most numerous class by composition, can develop millimeter-to-meter-scale fractures due to thermal stresses. However, signatures of this process on the second-most populous group of asteroids, the S-complex, have been poorly constrained. Here, we report observations of boulders’ fractures on Dimorphos, which is the moonlet of the S-complex asteroid (65803) Didymos, the target of NASA’s Double Asteroid Redirection Test (DART) planetary defense mission. We show that the size-frequency distribution and orientation of the mapped fractures are consistent with formation through thermal fatigue. The fractures’ preferential orientation supports that these have originated in situ on Dimorphos boulders and not on Didymos boulders later transferred to Dimorphos. Based on our model of the fracture propagation, we propose that thermal fatigue on rocks exposed on the surface of S-type asteroids can form shallow, horizontally propagating fractures in much shorter timescales (100 kyr) than in the direction normal to the boulder surface (order of Myrs). The presence of boulder fields affected by thermal fracturing on near-Earth asteroid surfaces may contribute to an enhancement in the ejected mass and momentum from kinetic impactors when deflecting asteroids.

Asteroids smaller than 10 km are thought to be rubble piles formed from the reaccumulation of fragments produced in the catastrophic disruption of parent bodies. Ground-based observations reveal that some of these asteroids are today binary systems, in which a smaller secondary orbits a larger primary asteroid. However, how these asteroids became binary systems remains unclear. Here, we report the analysis of boulders on the surface of the stony asteroid (65803) Didymos and its moonlet, Dimorphos, from data collected by the NASA DART mission. The size-frequency distribution of boulders larger than 5 m on Dimorphos and larger than 22.8 m on Didymos confirms that both asteroids are piles of fragments produced in the catastrophic disruption of their progenitors. Dimorphos boulders smaller than 5 m have size best-fit by a Weibull distribution, which we attribute to a multi-phase fragmentation process either occurring during coalescence or during surface evolution. The density per km2 of Dimorphos boulders ≥1 m is 2.3x with respect to the one obtained for (101955) Bennu, while it is 3.0x with respect to (162173) Ryugu. Such values increase once Dimorphos boulders ≥5 m are compared with Bennu (3.5x), Ryugu (3.9x) and (25143) Itokawa (5.1x). This is of interest in the context of asteroid studies because it means that contrarily to the single bodies visited so far, binary systems might be affected by subsequential fragmentation processes that largely increase their block density per km2. Direct comparison between the surface distribution and shapes of the boulders on Didymos and Dimorphos suggest that the latter inherited its material from the former. This finding supports the hypothesis that some asteroid binary systems form through the spin up and mass shedding of a fraction of the primary asteroid.

Images collected during NASA’s Double Asteroid Redirection Test (DART) mission provide the first resolved views of the Didymos binary asteroid system. These images reveal that the primary asteroid, Didymos, is flattened and has plausible undulations along its equatorial perimeter. At high elevations, its surface is rough and contains large boulders and craters; at low elevations its surface is smooth and possesses fewer large boulders and craters. Didymos’ moon, Dimorphos, possesses an intimate mixture of boulders, several asteroid-wide lineaments, and a handful of craters. The surfaces of both asteroids include boulders that are large relative to their host body, suggesting that both asteroids are rubble piles. Based on these observations, our models indicate that Didymos has a surface cohesion ≤ 1 Pa and an interior cohesion of ∼10 Pa, while Dimorphos has a surface cohesion of <0.9 Pa. Crater size-frequency analyzes indicate the surface age of Didymos is 40–130 times older than Dimorphos, with likely absolute ages of ∼ 12.5 Myr and <0.3 Myr, respectively. Solar radiation could have increased Didymos’ spin rate leading to internal deformation and surface mass shedding, which likely created Dimorphos.

In the present work, the viability of a novel recording geometry to produce reflection holographic couplers is analyzed. Recalling the idea of previous works, photopolymers are used as the recording material because they have been proven to be well-suited for the intended see-through application: the capability to provide a virtual image without compromising the information about the surrounding environment. Moreover, holography fundamentals give us the proper background to examine the proposed design, where no prisms or microlenses arrays are used. Aiming to support the analysis, we provide experimental evidence that the produced reflection holographic gratings exhibit the correct properties to work as a coupler, where the sensitivity of the material and its properties are studied and examined.

It is well known that Spatial Light Modulators (SLM) are of great interest and used in many different areas because of their continuous capability of light modulation and their potential as a linear variable retarder. However, high-definition SLM devices face the challenge of providing high performance under the influence of different phenomena, such as crosstalk between adjacent pixels, fringing fields, and diffraction effects arising from the finite pixel grid pattern. In this work, a numerical analysis that computes the director orientation as a function of the retardance across specific voltages (gray level) is compared to experimental results. More specifically, this work is focused on analysing how previously mentioned phenomena affect the interpretation of the residual twist angle in parallel-aligned (PA) on SLM. This twist angle is computed from the Stokes parameter and compared to the actual orientation of the director distribution.

We investigated the propagation of energy and momentum inside a small gravitational aggregate asteroid following a hypervelocity impact, comparable to NASA’s Double Asteroid Redirection Test on asteroid Dimorphos. We show that the impact energy damps rapidly inside different kinds of granular structures, unable to reach the antipodal hemisphere of the impact. However, global reshaping of the asteroid after the formation of a sizeable (> 1/3 of target size) crater causes meter-range displacement of boulders on the antipodal hemisphere due to mass rearrangement to achieve a new equilibrium shape. As a result, a surface depression opposite to the crater is formed, which may produce some surface refreshment. The boulder mass ejection following the synthetic DART-like impact is estimated to be at least 0.1% of the mass of the Dimorphos-like target, in agreement with recent detections of boulders ejected from the actual DART impact.

El espesor de la capa y la rigidez o flexibilidad del polímero formado tras la polimerización son dos factores importantes a tener en cuenta dependiendo del elemento óptico holográfico (EOH) a desarrollar. Para aplicaciones de EOH tipo lente es habitual que el polímero tenga un espesor de capa inferior a 50 micrómetros y una flexibilidad de capa muy limitada. El espesor de la capa influye en el rendimiento en difracción del EOH y por tanto en el rendimiento que consiga el propio elemento al realizar su función durante su uso. Por otra parte la flexibilidad de la capa es un parámetro de gran importancia en el caso de que el EOH vaya unido a soportes con curvatura. Una baja flexibilidad impide la adaptación del EOH al soporte, dificultando o impidiendo su uso en la práctica. En este trabajo se estudian las alternativas en cuanto a monómeros y entrecruzantes que permitan un espesor de capa mayor y una flexibilidad adecuada para adaptarse a soportes curvados.

Volume holographic reflection grating storage in eco-friendly photopolymers is a current challenge. Besides, they have the potential for usage in important applications such as sensors and holographic optical elements. The main objective of this work was the modification of the composition of Biophotopol, a low toxicity photopolymer based on poly(vinyl alcohol), in order to increase the diffraction efficiency of the reflection gratings. For it, high refractive index Platinum and Palladium nanoparticles were then added to the holographic material to improve refractive index modulation during the recording phase. The concentration of nanoparticles employed was taken into consideration. Using a concentration of 0.58 nanomoles of Platinum nanoparticles per gram of poly(vinyl alcohol), maximum diffraction efficiency above 50% was achieved. These were, to the best of our knowledge, the best results so far obtained for high-frequency holographic reflection gratings in a low-toxicity material.