Donostia International Physics Center
Archivo Digital para la Docencia y la InvestigaciónNot a member yet
46642 research outputs found
Sort by
Broad table-like magnetocaloric effect in the full hydrogen liquefaction range in Gd3Ni6XY
Get PDFGd3Ni6SiAl, Gd3Ni6SiGa, and Gd3Ni6AlGa (Ce3Ni6Si2-type, Im-3m, N 229, cI44) present a broad table-like magnetocaloric effect in the full hydrogen liquefaction range (20–77 K) with a real plateau wide enough to be competitive for refrigeration devices based on the Ericsson cycle. The characterization of the magnetocaloric variables (|ΔSMpk|= 6.60 J/kgK, TEC(10)= 6.44 J/kgK for Gd3Ni6SiGa, |ΔSMpk|= 6.05 J/kgK, TEC(10)= 6.01 J/kgK for Gd3Ni6SiAl, all at μ0ΔH=5 T) state that they are among the best of table-like magnetocaloric materials in this temperature range. The physical origin of this smooth and wide table-like effect is the combination of a spin reorientation transition (which appears in Gd3Ni6XY when Si or Ga is introduced) with the paramagnetic to ferromagnetic transition, close to each other. The application of the Banerjee criterion and the evolution of the critical exponent with temperature n(T) confirm that both transitions are second order, which is extremely relevant for real applications. From the study of the magnetic properties it has been inferred that the introduction of Si induces a magnetic ground state with combined ferromagnetic and antiferromagnetic components which turns to fully ferromagnetic at very low field. The critical exponents (β, γ, δ, n) have been found for the paramagnetic to ferromagnetic transitions; the values of γ (from 1.22 to 1.36) suggest that the magnetic interactions are short-range, though the ensembles do not correspond to any particular universality class.This work has been supported by Departamento de Educación del Gobierno Vasco (project IT1430–22) and from M.V. Lomonosov Moscow State University Program of Development. The authors thank for technical and human support provided by SGIker of UPV/EHU, specially the fruitful discussions with Dr. I. Orue
Paloma Martín-Esperanza, Hispania Restituta. La Antigüedad clásica en el programa político y cultural de los Reyes Católicos: relaciones entre España e Italia, Madrid: Consejo Superior de Investigaciones Científicas, 2023, 658 págs., ISBN: 978-84-00-11236-3
No full textActas del XVI Congreso Español de Metaheurísticas, Algoritmos Evolutivos y Bioinspirados (MAEB 2025)
No full text353 pEl XVI Congreso de Metaheurísticas, Algoritmos Evolutivos y Bioinspirados (MAEB) se celebró en Donostia/San Sebastián del 28 al 30 de mayo. Esta edición marca el retorno del congreso a su formato independiente, retomando así su estilo inicial tras haber formado parte de otros eventos científicos desde 2015. El MAEB siempre ha constituido un foro esencial donde investigadores, académicos y estudiantes convergen para compartir avances en metaheurísticas, algoritmos evolutivos y técnicas bioinspiradas. Para esta decimosexta edición, se ha ampliado el formato tradicional incorporando dos nuevas modalidades de participación: key-work dirigido a visibilizar trabajos publicados de relevancia, y proyectos, orientados a explorar formas innovadoras de gestionar y difundir la investigación científica
Uncovering longitudinal changes in the brain functional connectome along the migraine cycle: a multilevel clinical connectome fngerprinting framework
No full textPublished on: 11 February 2025Background Changes in large-scale brain networks have been reported in migraine patients, but it remains unclear
how these manifest in the various phases of the migraine cycle. Case-control fMRI studies spanning the entire
migraine cycle are lacking, precluding a complete assessment of brain functional connectivity in migraine. Such stud ies are essential for understanding the inherent changes in the brain of migraine patients as well as transient changes
along the cycle. Here, we leverage the concept of functional connectome (FC) fngerprinting, whereby individual
subjects may be identifed based on their FC, to investigate changes in FC and its stability across diferent phases
of the migraine cycle.
Methods We employ a case-control longitudinal design to study a group of 10 patients with episodic menstrual
or menstrual-related migraine without aura, in the 4 phases of their spontaneous migraine cycle (preictal, ictal, postic tal, interictal), and a group of 14 healthy controls in corresponding phases of the menstrual cycle, using resting-state
functional magnetic resonance imaging (fMRI). We propose a novel multilevel clinical connectome fngerprinting
approach to analyse the FC identifability not only within-subject, but also within-session and within-group.
Results This approach allowed us to obtain individual FC fngerprints by reconstructing the data using the frst
19 principal components to maximize identifability at all levels. We found decreased FC identifability for patients
in the preictal phase relative to controls, which increased with the progression of the attack and became comparable
to controls in the interictal phase. Using Network-Based Statistic analysis, we found increased FC strength across sev eral brain networks for patients in the ictal and postictal phases relative to controls.
Conclusion Our novel multilevel clinical connectome fngerprinting approach captured FC variations
along the migraine cycle in a case-control longitudinal study, bringing new insights into the cyclic nature
of the disorder.This work was supported by LARSyS FCT funding [DOI: https://doi.org/10.
54499/LA/P/0083/2020, https://doi.org/10.54499/UIDP/50009/2020, and
https://doi.org/10.54499/UIDB/50009/2020], PRR project Center for Respon sible AI [grant C645008882-00000055] and FCT [grants PD/BD/150356/2019,
PTDC/EMD-EMD/29675/2017, LISBOA-01-0145-FEDER-029675
Immobilization of Enzyme–Polymer Hybrids and Nanozymes Through Electrostatic Interactions: Toward Multicatalytic Microreactors with Controlled Nanoarchitecture
No full textThe optimal allocation of catalysts and their precise compartmentalization are vital to ensure efficient cascade reactions. The layer-by-layer approach offers the possibility of assembling various building blocks onto templates of different sizes and shapes, thus representing a powerful tool for fabricating multicatalytic reactors with controlled nanoarchitecture. However, this process usually relies on electrostatic interactions between building blocks, which means a limitation when working with natural enzymes. Accordingly, both the loading capacity and control over membrane architecture are compromised by the inherent surface charge of the enzymes. Here, this study introduces a modular strategy to assemble engineered enzyme-polymer hybrids and inorganic nanozymes onto colloidal templates, giving rise to multicatalytic reactors. The surface charge of the engineered enzyme–polymer hybrids can be finely tuned, allowing their à-la-carte assembly into multilayer membranes. Following this approach, the distance between catalytic units and their arrangement on colloidal templates at the nano- and micrometer scale can be precisely controlled, resulting in optimized configurations with enhanced cascade efficiency. The synthesized multicatalytic reactors can reduce the metabolic activity of human pancreatic stellate cells, confirming their functional activity in biological microenvironments and highlighting their potential for biomedical applications.This work was supported by a Research Grant from the Royal Society (no. RG\R2\232019), by the EPSRC National Facility for XPS (“HarwellXPS,” EP/Y023587/1, EP/Y023609/1, EP/Y023536/1, EP/Y023552/1, and EP/Y023544/1), and the Henry Royce Institute for Advanced Materials, funded through EPSRC grants EP/R00661X/1, EP/S019367/1, EP/P025021/1, and EP/P025498/1. The authors also thank the staff in the electron microscopy (EM) Core Facility in the Faculty of Biology, Medicine and Health (University of Manchester) and the Wellcome Trust for equipment grant support to the EM Core Facility (RRID: SCR_021147). AB thanks the University of the Basque Country (GIU21/033); the Spanish Research Agency (PID2022-142128NB-I00 and CNS2023-145416 funded by MCIN/AEI/10.13039/501100011033/; and the “European Union NextGenerationEU/PRTR”; “María de Maeztu” Programme for Center of Excellence in R&D, grant CEX2023-001303-M funded by MICIU/AEI/10.13039/501100011033), and IKERBASQUE-Basque Foundation for Science. AO thanks grant ayuda Predoctoral de Formación de Personal Investigador no Doctor, Departamento de Ciencia, Universidades e Innovación Eusko Jaurlaritza-Gobierno Vasco (PRE_2023_1_0235). AL is thankful for funds from the Basque Government, Department of Education (IT-1766-22). AL also acknowledges support from the María de Maeztu Excellence Unit CEX2023-001303-M funded by MCIN/AEI/10.13039/501100011033
Investigar (en arte): Crear, transmitir, e intentar no confundir
No full textThe starting point based on the recognition of the specific knowledge of art and its (potential) transmission, leads to the necessary research questions that the article tries to put on the table, based on various existing methods and paradigms. Contemporary antecedents that have taken art as the objective of (their) research, or have attempted to outline channels to research (in) art as raw material. The body of content runs through the intricacies of the ways of researching (not in use) in the face of creation, teaching or transmission, putting the emphasis on the methodologies whose differences, but also equivalent aspects, are susceptible to highlighting. Finally, how they are made the records, validations and subsequent 'evaluations' of said research, are relevant aspects for its adaptation to the agreed parameters of verification.; La fundamentación de partida sobre la base del reconocimiento del saber específico del arte y su (potencialidad) de transmisión, conducen hacia las necesarias cuestiones de la investigación que el artículo trata de poner sobre la mesa, a raíz de diversos métodos y paradigmas existentes. Antecedentes contemporáneos que han tomado al arte como objetivo de (su) investigación, o han pretendido perfilar cauces para investigar (en) el arte como materia-prima. El cuerpo de contenidos discurre por los entresijos de las formas de investigar (no al uso) de cara a la creación, la enseñanza o la transmisión, poniendo el acento sobre las metodologías cuyas diferencias, pero también aspectos equivalentes, son susceptibles de subrayar. Finalmente, cómo se realizan los registros, validaciones y consiguientes ‘evaluaciones’ de dicha investigación son vertientes relevantes para su adecuación a los parámetros consensuados de verificación
Topology effects in photodynamic therapy with phthalocyanine nanocarriers
No full textTwo different amphiphilic copolymers, a random copolymer (RCP) and a block copolymer (BCP), have been used to encapsulate a far-red photosensitizing hydrophobic zinc phthalocyanine while forming self-assembled nanocarriers of different topology: self-folded single-chain nanoparticles (SCNPs) and star-like aggregates (SLAs), respectively. Different copolymer/phthalocyanine ratios have been tested to assess their effect on structural properties which were determined by small-angle X-ray scattering (SAXS) measurements. The relevance of these materials as photosensitizer nanocarriers for photodynamic therapy (PDT) has been studied against human breast cancer cells (MCF-7). A better PDT effect was found for the SCNP-Pc2x (100 μg mL−1) excited at 800 nm with a pulsed laser than for the SLA-Pc2x under identical conditions. Conversely, irradiation at slightly lower wavelengths (740 nm) of MCF-7 cells incubated with SLA-Pc2x resulted in a notorious PDT effect when compared to that observed for MCF-7 cells incubated with the SCNP-Pc2x. These systems represent new strategies for the encapsulation of photosensitizers for photodynamic therapy.D. A., E. V.-S., A. I., A. A. and J. A. P. gratefully acknowledge Grant PID2021-123438NB-I00 funded by MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe”; Grant TED2021-130107A-I00 funded by MCIN/AEI/10.13039/501100011033 and Unión Europea “NextGenerationEU/PRTR”, Grant IT-1566-22 from Eusko Jaurlaritza (Basque Government), and financial support from RyC program (RYC2022-037590-I). We acknowledge the imaging facility MRI, member of the France-BioImaging national infrastructure supported by the French National Research Agency (ANR-10-INBS-04, “Investments for the future”)
Scalability and performance evaluation of DECT NR+ for IOT connectivity
No full textThis thesis explores the emerging Digital Enhanced Cordless Telecommunications New Radio + (DECT NR+) technology, focusing the work in examining and evaluating its capabilities, performance, and position within the landscape of Low-Power Wide-Area Network (LP-WAN) technologies and the fulfillments of the requirements for the new use cases designed for 5G. Through simulations using NS3 and MATLAB, the study evaluates the scalability of the technology. Moreover, an extensive performance analysis with the first generation of compatible devices has been conducted by designing, developing, and executing targeted scenarios to test key performance parameters. The results of this evaluations have been compared to the requirements of the 5G use cases for this technology was designed for and a specific use case has been developed taking into account on what the technology offers. Based on the evaluation, a novel use case leveraging DECT NR+'s unique features was developed, showcasing its potential applications in smart lighting applications. This research contributes to the understanding of DECT NR+ as a viable LP-WAN technology for the 5G ecosystems.Esta tesis explora la tecnología emergente Digital Enhanced Cordless Telecommunications New Radio + (DECT NR+), centrándose en el examen y evaluación de sus capacidades, rendimiento y posición dentro del panorama de las tecnologías de Red de Área Amplia de Bajo Consumo (LP-WAN) y el cumplimiento de los requisitos para los nuevos casos de uso diseñados para 5G. A través de simulaciones utilizando NS3 y MATLAB, el estudio evalúa la escalabilidad de la tecnología. Además, se ha realizado un análisis exhaustivo del rendimiento con la primera generación de dispositivos compatibles mediante el diseño, desarrollo y ejecución de escenarios dirigidos para probar parámetros clave de rendimiento. Los resultados de estas evaluaciones han sido comparados con los requisitos de los casos de uso 5G para los que fue diseñada esta tecnología y se ha desarrollado un caso de uso específico para iluminación inteligente en el contexto de Smart Cities teniendo en cuenta las capacidades de la tecnología. Esta investigación contribuye al entendimiento de DECT NR+ como una tecnología LP-WAN viable para los ecosistemas 5G.Tesi honek DECT NR+ teknologia aztertzen du, bere gaitasunen, errendimenduaren eta LPWAN teknologien panoramaren barruan duen posizioaren azterketan eta ebaluazioan zentratuz, eta 5G-rako diseinatutako erabilera-kasu berrietarako baldintzak betetzen diren aztertuz. NS3 eta MATLAB erabiliz egindako simulazioen bidez, ikerketak teknologiaren eskalagarritasuna ebaluatzen du. Baita ere, errendimenduaren azterketa sakona burutu da gailu bateragarrien erabilerari esker, errendimenduaren funtsezko parametroak probatzeko agertoki gidatuak diseinatuz, garatuz eta gauzatuz. Ebaluazio horien emaitzak teknologia hori diseinatu zen 5G erabilera-kasuetako baldintzekin konparatu dira, eta argiztapen adimendunerako erabilera-kasu bat garatu da Smart Cities-en testuinguruan, teknologiaren ahalmenak kontuan hartuta. Ikerketa honek DECT NR+ 5G ekosistemetarako bideragarria den LPWAN teknologia gisa ulertzen laguntzen du
Polypeptide-based multilayer capsules with anti-inflammatory properties: exploring different strategies to incorporate hydrophobic drugs
No full textMore than 90% of drug candidates used in the drug development pipeline and about 40% of drugs on the market are poorly soluble in water based on the definition of the biopharmaceutical classification system. The advent of drug delivery approaches has represented a striking tool to overcome the challenges associated with the use of hydrophobic drugs, such as their low bioavailability and off-target effects. Drug carrier formulations composed of biodegradable and biocompatible polymers, such as polypeptides, have been explored as platforms to host poorly water-soluble drugs to prolong drug circulation, enhance their safety, reduce their immunogenicity, and promote their controlled release. In this work, we evaluated three strategies—co-precipitation, post-encapsulation, and conjugation—to incorporate a hydrophobic model drug, i.e., curcumin (CUR), into biodegradable multilayer capsules fabricated via a layer-by-layer (LbL) approach. Poly(L-lysine) (PLys) and poly(L-glutamic acid) (PGlu) were adopted as building blocks and alternately assembled onto calcium carbonate (CaCO3) microparticles to build a polypeptide-multilayer membrane, which acted as a barrier to control the release of the drug. The application of our three formulations in in vitro inflammatory models of THP-1 derived human macrophages and murine microglia showed a reduction of the inflammation with the suppression of three pivotal pro-inflammatory cytokines (i.e., interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α). Moreover, the intracellular release of CUR detected upon uptake studies on activated microglia suggested that our systems could represent a potential therapeutic approach to reduce acute neuroinflammation and modulate microglia phenotype.The authors acknowledge the financial support from the Basque Government (projects 2023333010, 2023333023, PIBA2023-1-0043, IT-1766-22, IKUR Strategy), the University of the Basque Country (projects COLLAB22/05 and GIU21/033), the IKERBASQUE-Basque Foundation for Science, the Ministry of Science and Innovation of the Government of Spain (grant PID2022-142739OB-I00 funded by MICIU/AEI/10.13039/501100011033 and by FEDER, UE; 'María de Maeztu' Programme for Center of Excellence in R&D, grant CEX2023-001303-M funded by MICIU/AEI/10.13039/501100011033; PID2022-142128NB-I00 funded by MCIN/AEI/10.13039/501100011033/and by the “European Union NextGenerationEU/PRTR”; RYC2018-025923-I from RyC program – MCIN/AEI/10.13039/501100011033 and FSE “invierte en tu futuro”). SGIker technical services (UPV/EHU) are gratefully acknowledged for the support in ATR-FTIR, confocal microscopy, XRD, and SEM. Open Access funding provided by University of the Basque Country
Karbono nitruroan eta titanio dioxidoan oinarritutako MOFen ezarpena karbono dioxidoaren erredukziorako
No full textKarbono dioxidoaren (CO₂) biltegiratzea eta berrerabilpena klima-aldaketa arintzeko erronka handienetako bat dira. CO₂ betirako lurpean biltegiratu daitekeen arren, alternatiba bat konposatu kimiko eta erregai baliotsu bihurtzea da katalisi-prozesuen bidez. Metodo horien artean, CO₂ren fotoredukzioa bide jasangarri bat da, eguzki-energia erabiliz karbono-konposatu bihurtzeko. Hala ere, prozesu honen eraginkortasuna nagusiki fotoaktibo gisa erabiltzen diren katalizatzaileen aukeraketaren eta haien egiturazko propietateen araberakoa da.
Karbono nitruroa (C₃N₄) eta titanio dioxidoa (TiO₂) bezalako material fotoaktiboek funtsezko eginkizuna dute CO₂ren fotoredukzioan, katalizatzaile gisa jardunez, argia xurgatu eta erreakzioa erraztuz. Katalisiaren errendimendua hobetzeko, material mesoporotsuak gehitu daitezke CO₂ren xurgapena handitzeko, gainazal-eremu handiagoa eta difusio-bide eraginkorragoak eskainiz. Horrez gain, material hauetan metalezko-organikoen egiturak (MOF) integratzea estrategia eraginkorra da, substratuaren espezifikotasuna, selektibitatea eta eraginkortasun orokorra hobetzeko. MOFak poro handia, egitura doigarria eta gune metaliko aktiboak dituzten materialak dira, eta erreakzio-bideak eraldatu eta CO₂ aktibazioan lagundu dezakete
Hala ere, MOFen eta fotoaktiboen euskarriaren arteko elkarrekintzak eragin nabarmena du egonkortasun estrukturalean, karga-transferentziaren dinamikan eta eraginkortasun katalitikoan. MOFak oso sentikorrak dira hazkuntza-ingurunearen eta interfazean gertatzen diren interakzioen aurrean, eta, ondorioz, euskarri-materialaren hautaketak MOFen portaeran eragina du MOF@euskarri heterojuntzioetan. Azalera-kimika, porositatea eta propietate elektronikoak bezalako faktoreen aldeek karbono nitruroaren eta titanio dioxidoaren gainean MOFen nukleazioa, hazkundea eta katalizatzailearekiko interakzioa baldintzatuko dute, eta, azken batean, CO₂ren fotoredukzioaren jarduera baldintzatuko dute.
Ikerketa honek HKUST-1 MOFa bi euskarri fotoaktibo ezberdinetan haztearen eragina aztertzen du: karbono nitruro grafitiko mesoporotsua (mpg-C₃N₄) eta titanio dioxidoa (TiO₂). Geruzaz geruza gehiketa-metodo bat erabiliz, gainazaleko lotura, interfazean gertatzen den karga-transferentzia eta elkarrekintza katalitikoak aztertzen ditugu CO₂ren fotoredukzioan. Esperimentuak batch sistema itxi batean egiten dira, ura elektroi emaile gisa erabiliz, erreakzio-baldintza kontrolatuetan fotokatalizatzaile-MOF konbinazio ezberdinen errendimendua alderatzeko. HKUST-1 material hauekin nola integratzen den ulertzeak aukera emango du hibrido fotoaktiboak optimizatzeko, CO₂ren bihurtze-eraginkortasuna, produktu-selektibitatea eta epe luzerako egonkortasuna hobetzeko, eguzki-energia bidezko karbono-berrerabilpen teknologiak garatzeko