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1.
ACS Appl Mater Interfaces ; 16(19): 24624-24630, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38699998

RESUMEN

The structure and growth of the solid electrolyte interphase (SEI) region between an electrolyte and an electrode is one of the most fundamental yet less well-understood phenomena in solid-state batteries. We present an atomistic simulation of the SEI growth for one of the currently promising solid electrolytes (Li6PS5Cl), based on ab initio-trained machine learning interatomic potentials, for over 30,000 atoms during 10 ns, well beyond the capabilities of conventional molecular dynamics. This unveils a two-step growth mechanism: a Li-argyrodite chemical reaction leading to the formation of an amorphous phase, followed by a kinetically slower crystallization of the reaction products into a 5Li2S·Li3P·LiCl solid solution. The simulation results support the recent, experimentally founded hypothesis of an indirect pathway of electrolyte reduction. These findings shed light on the intricate processes governing SEI evolution, providing a valuable foundation for the design and optimization of next-generation solid-state batteries.

2.
ACS Energy Lett ; 8(10): 4129-4135, 2023 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-37854046

RESUMEN

The development of high-energy-dense, sustainable all-solid-state batteries faces a major challenge in achieving compatibility between the anode and electrolyte. A promising solution lies in the use of highly ion-conductive solid electrolytes, such as those from the argyrodite family. Previous studies have shown that the ionic conductivity of the argyrodite Li6PS5Cl can be significantly enhanced by partially substituting S with Se. However, there remains a lack of fundamental knowledge regarding the effect of doping on the interfacial stability. In this study, we employ long-scale ab initio molecular dynamics simulations, which allowed us to gain unprecedented insights into the process of solid electrolyte interface (SEI) formation. The study focuses on the stage of nucleation of crystalline products, enabling us to investigate in silico the SEI formation process of Se-substituted Li6PS5Cl. Our results demonstrate that kinetic factors play a crucial role in this process. Importantly, we discovered that selective anionic substitution can accelerate the formation of a stable interface, thus potentially resolving anode-electrolyte compatibility issues.

3.
Phys Chem Chem Phys ; 25(36): 25038-25054, 2023 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-37698851

RESUMEN

Model validation of a well-known class of solid polymer electrolyte (SPE) is utilized to predict the ionic structure and ion dynamics of alternative alkali metal ions, leading to advancements in Na-, K-, and Cs-based SPEs for solid-state alkali metal batteries. A comprehensive study based on molecular dynamics (MD) is conducted to simulate ion coordination and the ion transport properties of poly(ethylene oxide) (PEO) with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt across various LiTFSI concentrations. Through validation of the MD simulation results with experimental techniques, we gain a deeper understanding of the ionic structure and dynamics in the PEO/LiTFSI system. This computational approach is then extended to predict ion coordination and transport properties of alternative alkali metal ions. The ionic structure in PEO/LiTFSI is significantly influenced by the LiTFSI concentration, resulting in different lithium-ion transport mechanisms for highly concentrated or diluted systems. Substituting lithium with sodium, potassium, and cesium reveals a weaker cation-PEO coordination for the larger cesium-ion. However, sodium-ion based SPEs exhibit the highest cation transport number, indicating the crucial interplay between salt dissociation and cation-PEO coordination for achieving optimal performance in alkali metal SPEs.

4.
EMBO J ; 42(19): e113246, 2023 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-37575021

RESUMEN

Neuronal hyperactivity is a key feature of early stages of Alzheimer's disease (AD). Genetic studies in AD support that microglia act as potential cellular drivers of disease risk, but the molecular determinants of microglia-synapse engulfment associated with neuronal hyperactivity in AD are unclear. Here, using super-resolution microscopy, 3D-live imaging of co-cultures, and in vivo imaging of lipids in genetic models, we found that spines become hyperactive upon Aß oligomer stimulation and externalize phosphatidylserine (ePtdSer), a canonical "eat-me" signal. These apoptotic-like spines are targeted by microglia for engulfment via TREM2 leading to amelioration of Aß oligomer-induced synaptic hyperactivity. We also show the in vivo relevance of ePtdSer-TREM2 signaling in microglia-synapse engulfment in the hAPP NL-F knock-in mouse model of AD. Higher levels of apoptotic-like synapses in mice as well as humans that carry TREM2 loss-of-function variants were also observed. Our work supports that microglia remove hyperactive ePtdSer+ synapses in Aß-relevant context and suggest a potential beneficial role for microglia in the earliest stages of AD.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Ratones , Animales , Enfermedad de Alzheimer/genética , Microglía , Sinapsis , Modelos Animales de Enfermedad , Péptidos beta-Amiloides/genética , Glicoproteínas de Membrana/genética , Receptores Inmunológicos/genética
5.
Front Chem ; 11: 1191394, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37502234

RESUMEN

Sulfonimide salts are of great interest for battery use thanks to their special properties including sufficient superior chemical/thermal stabilities, structural flexibility, etc. In particular, the hydrogen-containing sulfonimide (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide anion {[N(SO2CF2H) (SO2CF3)]-, DFTFSI-}, stands out owing to its suppressed anion mobility and superior electrochemical properties. We herein report the structural analyses of potassium (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide {K [N(SO2CF2H) (SO2CF3)], KDFTFSI} by virtue of single crystal X-ray diffraction and computational approaches. Our results reveal that KDFTFSI crystallizes in a orthorhombic cell (space group: Pbcn) comprising of cationic and anionic layers, which is similar to the conventional sulfonimide salt, potassium bis(trifluoromethanesulfonyl)imide {K [N(SO2CF3)2], KTFSI}. Gas-phase density functional theory calculations show that the conversion from trans to cis DFTFSI- anions is hindered due to the presence of stabilizing intramolecular H-bonding interactions in the trans conformer; yet interaction with K+ substantially minimizes the energy difference between the two conformers due to the formation of strong tridentate K+ coordination with oxygen atoms in the cis KDFTFSI. This work is anticipated to provide further understanding on the structure-property relations of hydrogenated sulfonimide anions, and thus inspire the structural design of new anions for battery research.

6.
Nat Neurosci ; 26(3): 406-415, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36747024

RESUMEN

Alzheimer's disease (AD) is characterized by synaptic loss, which can result from dysfunctional microglial phagocytosis and complement activation. However, what signals drive aberrant microglia-mediated engulfment of synapses in AD is unclear. Here we report that secreted phosphoprotein 1 (SPP1/osteopontin) is upregulated predominantly by perivascular macrophages and, to a lesser extent, by perivascular fibroblasts. Perivascular SPP1 is required for microglia to engulf synapses and upregulate phagocytic markers including C1qa, Grn and Ctsb in presence of amyloid-ß oligomers. Absence of Spp1 expression in AD mouse models results in prevention of synaptic loss. Furthermore, single-cell RNA sequencing and putative cell-cell interaction analyses reveal that perivascular SPP1 induces microglial phagocytic states in the hippocampus of a mouse model of AD. Altogether, we suggest a functional role for SPP1 in perivascular cells-to-microglia crosstalk, whereby SPP1 modulates microglia-mediated synaptic engulfment in mouse models of AD.


Asunto(s)
Enfermedad de Alzheimer , Ratones , Animales , Enfermedad de Alzheimer/metabolismo , Microglía/metabolismo , Osteopontina/metabolismo , Fagocitos/metabolismo , Macrófagos/metabolismo , Fagocitosis , Modelos Animales de Enfermedad , Péptidos beta-Amiloides/metabolismo
7.
J Phys Chem C Nanomater Interfaces ; 127(4): 1955-1964, 2023 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-36761231

RESUMEN

The advent of Li-metal batteries has seen progress toward studies focused on the chemical modification of solid polymer electrolytes, involving tuning either polymer or Li salt properties to enhance the overall cell performance. This study encompasses chemically modifying simultaneously both polymer matrix and lithium salt by assessing ion coordination environments, ion transport mechanisms, and molecular speciation. First, commercially used lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt is taken as a reference, where F atoms become partially substituted by one or two H atoms in the -CF3 moieties of LiTFSI. These substitutions lead to the formation of lithium(difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide (LiDFTFSI) and lithium bis(difluoromethanesulfonyl)imide (LiDFSI) salts. Both lithium salts promote anion immobilization and increase the lithium transference number. Second, we show that exchanging archetypal poly(ethylene oxide) (PEO) with poly(ε-caprolactone) (PCL) significantly changes charge carrier speciation. Studying the ionic structures of these polymer/Li salt combinations (LiTFSI, LiDFTFSI or LiDFSI with PEO or PCL) by combining molecular dynamics simulations and a range of experimental techniques, we provide atomistic insights to understand the solvation structure and synergistic effects that impact macroscopic properties, such as Li+ conductivity and transference number.

8.
Neurotoxicology ; 94: 98-107, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36402194

RESUMEN

Adolescence is a critical period for brain maturation in which this organ is more vulnerable to the damaging effects of ethanol. Administration of ethanol in mice induces a rapid cerebral upregulation of pleiotrophin (PTN), a cytokine that regulates the neuroinflammatory processes induced by different insults and the behavioral effects of ethanol. PTN binds Receptor Protein Tyrosine Phosphatase (RPTP) ß/ζ and inhibits its phosphatase activity, suggesting that RPTPß/ζ may be involved in the regulation of ethanol effects. To test this hypothesis, we have treated adolescent mice with the RPTPß/ζ inhibitor MY10 (60 mg/kg) before an acute ethanol (6 g/kg) administration. Treatment with MY10 completely prevented the ethanol-induced neurogenic loss in the hippocampus of both male and female mice. In flow cytometry studies, ethanol tended to increase the number of NeuN+/activated Caspase-3+ cells particularly in female mice, but no significant effects were found. Ethanol increased Iba1+ cell area and the total marked area in the hippocampus of female mice, suggesting sex differences in ethanol-induced microgliosis. In addition, ethanol reduced the circulating levels of IL-6 and IL-10 in both sexes, although this reduction was only found significant in males and not affected by MY10 treatment. Interestingly, MY10 alone increased the total marked area and the number of Iba1+ cells only in the female hippocampus, but tended to reduce the circulating levels of TNF-α only in male mice. In summary, the data identify a novel modulatory role of RPTPß/ζ on ethanol-induced loss of hippocampal neurogenesis, which seems unrelated to glial and inflammatory responses. The data also suggest sex differences in RPTPß/ζ function that may be relevant to immune responses and ethanol-induced microglial responses.


Asunto(s)
Proteínas Tirosina Fosfatasas Clase 5 Similares a Receptores , Transducción de Señal , Animales , Femenino , Masculino , Ratones , Citocinas/metabolismo , Etanol/toxicidad , Hipocampo/metabolismo , Neurogénesis , Proteínas Tirosina Fosfatasas Clase 5 Similares a Receptores/metabolismo
9.
Phys Rev E ; 105(6-1): 064119, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35854549

RESUMEN

We study a quantum battery made out of N nonmutually interacting qubits coupled to a dissipative single electromagnetic field mode in a resonator. We quantify the charging energy, ergotropy, transfer rate, and power of the system, showing that collective enhancements are still present despite losses, and can even increase with dissipation. Moreover, we observe that a performance deterioration due to dissipation can be reduced by scaling up the battery size. This is useful for experimental realizations when controlling the quality of the resonator and the number of qubits are limiting factors.

10.
J Cosmet Dermatol ; 21(11): 5610-5613, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35839384

RESUMEN

INTRODUCTION: Hyaluronic acid is a safe dermal filler, but sometimes late granuloma is generated. This adverse effect is an inflammatory process, and its causes are not clear. Late granuloma generation could be due to the reaction to residual components of the bacterial wall present into hyaluronic acid, such as lipoteichoic acid (LTA). Other possibility is hyaluronic acid degraded could be trigger this inflammatory reaction. OBJECTIVE: Study possible molecular mechanism that could be implicated into the late granuloma formation. We wonder whereas inflammatory response activation is triggered by lower molecular weight hyaluronic acid or Gram-positive bacterial components as LTA. METHODS: We analyzed one adverse case generated by hyaluronic acid injections. Our study with one nodule through chemical and immunofluorescence histologic technics. RESULTS: In this case, observe a late granuloma without infectious process. Histological analysis shown few large Langerhans cells around fillers and multiple immunological cells infiltrated. Immunofluorescent study shown immunological cells (CD45 positives cells) with high TLR2 expression (hyaluronic acid and LTA receptor). LIMITATIONS: The difficulty of obtaining biopsy samples of nodules implies that the number of cases analyzed is very low. CONCLUSION: New model is proposed in which weight of hyaluronic acid and LTA could be able to trigger inflammation. This process could be mediated by TLR2 expressed in infiltrated immune cells.


Asunto(s)
Rellenos Dérmicos , Ácido Hialurónico , Humanos , Ácido Hialurónico/efectos adversos , Receptor Toll-Like 2 , Peso Molecular , Inflamación/inducido químicamente , Granuloma/inducido químicamente , Rellenos Dérmicos/efectos adversos
11.
Environ Sci Pollut Res Int ; 29(53): 81048-81062, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35729380

RESUMEN

Every year the concern from environmental pollution increases as it affects human health. In the current paper, it is analyzed the evolution of the air quality in different cities on international level related to the reduction in mobility trend due to the emergence of the pandemic. The air pollution is studied in order to achieve healthier cities in the future and create an awareness for the citizens. The COVID-19 pandemic situation was declared during the first months of 2020 and has shown (indirectly) the effects that restrictions on human activity and road traffic have on atmospheric pollutant values. This pandemic condition derived, in most cases, in mobility restrictions in order to decrease the spread of the virus through the density of population in different places and, as a result of these restrictions, pollutant presence decreased equally. This article analyzes some of the largest cities around the world, such as Tsuen Wan district in Hong Kong (China), Los Angeles (USA), London (UK), São Paulo (Brazil), Bangalore (India), Johannesburg (South Africa), and Sydney (Australia) in order to check the different mobility restriction policies established in each location, and how those restrictions led to decrease the levels of some pollutant particles such as NO2 in the atmosphere. This should serve as a focus of awareness of the city and political interests of how it affects human activity, and those measures should be taken to reduce pollutants.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , COVID-19 , Humanos , Ciudades , Pandemias , Contaminantes Atmosféricos/análisis , Material Particulado/análisis , Dióxido de Nitrógeno/análisis , Brasil , Sudáfrica , India , Contaminación del Aire/análisis , Monitoreo del Ambiente
12.
J Am Chem Soc ; 144(22): 9806-9816, 2022 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-35638261

RESUMEN

Polymer electrolytes (PEs) with excellent flexibility, processability, and good contact with lithium metal (Li°) anodes have attracted substantial attention in both academic and industrial settings. However, conventional poly(ethylene oxide) (PEO)-based PEs suffer from a low lithium-ion transference number (TLi+), leading to a notorious concentration gradient and internal cell polarization. Here, we report two kinds of highly lithium-ion conductive and solvent-free PEs using the benzene-based lithium salts, lithium (benzenesulfonyl)(trifluoromethanesulfonyl)imide (LiBTFSI) and lithium (2,4,6-triisopropylbenzenesulfonyl)(trifluoromethanesulfonyl)imide (LiTPBTFSI), which show significantly improved TLi+ and selective lithium-ion conductivity. Using molecular dynamics simulations, we pinpoint the strong π-π stacking interaction between pairs of benzene-based anions as the cause of this improvement. In addition, we show that Li°âˆ¥Li° and Li°âˆ¥LiFePO4 cells with the LiBTFSI/PEO electrolytes present enhanced cycling performance. By considering π-π stacking interactions as a new molecular-level design route of salts for electrolyte, this work provides an efficient and facile novel strategy for attaining highly selective lithium-ion conductive PEs.

13.
J Colloid Interface Sci ; 623: 870-882, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35636295

RESUMEN

A better molecular-level understanding of Li+ diffusion through ceramic/polymer interfaces is key to design high-performance composite solid-state electrolytes for all-solid-state batteries. By considering as a case study a composite electrolyte constituted by Li+ conductive Ga3+ doped-Li7La3Zr2O12 (LLZO) garnet fillers embedded within a poly(ethylene oxide) and lithium bis(trifluoromethanesulfonyl) imide polymer matrix (PEO(LiTFSI)), we investigate Li+ interfacial dynamics at conditions of high polymer confinement, with large filler particles in a fully amorphous polymer phase. Such confinement scenario is aimed to capture the conditions near the percolation threshold, at which conductivity enhancement is often reported. Using molecular dynamics simulations combined with the generalized shadow hybrid Monte Carlo method and umbrella sampling calculations, we explain why the hopping towards the polymer phase of the Li+ sitting on the LLZO surface is thermodynamically hindered, while hopping of Li+ from the polymer to the LLZO is kinetically slowed-down by rigidified polymer near the interface. In addition, we demonstrate how the overlap of LLZO-bound polymer chains at high confinement leads to a decrease of Li+ diffusivity within the interstitial space. We put forward that these insights are relevant to interpret the variation of ionic conductivity as a function of volume fraction and filler particle sizes also below the glass transition temperature of the polymer, at the typical operating conditions of lithium ion batteries.

14.
J Chem Phys ; 156(17): 174702, 2022 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-35525650

RESUMEN

Magnesium has attracted growing interest for its use in various applications, primarily due to its abundance, lightweight properties, and relatively low cost. However, one major drawback to its widespread use remains to be its reactivity in aqueous environments, which is poorly understood at the atomistic level. Ab initio density functional theory methods are particularly well suited to bridge this knowledge gap, but the explicit simulation of electrified water/metal interfaces is often too costly from a computational viewpoint. Here, we investigate water/Mg interfaces using the computationally efficient implicit solvent model VASPsol. We show that the Mg (0001), (101̄0), and (101̄1) surfaces each form different electrochemical double layers due to the anisotropic smoothing of the electron density at their surfaces, following Smoluchowski rules. We highlight the dependence that the position of the diffuse cavity surrounding the interface has on the potential of zero charge and the electron double layer capacitance, and how these parameters are also affected by the addition of explicit water and adsorbed OH molecules. Finally, we calculate the equilibrium potential of Mg2+/Mg0 in an aqueous environment to be -2.46 V vs a standard hydrogen electrode, in excellent agreement with the experiment.

15.
Cancers (Basel) ; 14(5)2022 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-35267491

RESUMEN

Retrospective studies reported that preoperative oxaliplatin-based chemotherapy increased pathological response (PR) in patients resected for colorectal liver metastases (CRLM). This multicenter prospective randomized (1/1) phase II trial evaluated PR on resected CRLM after preoperative mFOLFOX6 (arm A) or FOLFIRI (arm B) + bevacizumab. The primary endpoint was the major pathological response rate (MPRR), defined as the percentage of patients presenting CRLMs with mean tumor regression grade (TRG) < 3. Secondary endpoints included safety, progression-free survival (PFS) and overall survival (OS). Out of 65 patients, 57 patients (28 and 29 in arm A/B) were resected for CRLM (one patient with lung metastases). Clinical and treatment characteristics were similar in both arms. One-month postoperative complications were 39.3%/31.0% in arm A/B (p = 0.585). MPRR and complete PR were 32.1%/20.7% (p = 0.379) and 14.3%/0.0% (p = 0.052) in arm A/B, respectively. PFS and OS were not different. Patients with PR among all CRLMs (max TRG ≤ 3; 43.8% of patients) had a lower risk of relapse (PFS: HR = 0.41, 95%CI = 0.204−0.840, p = 0.015) and a tendency towards better survival (OS: HR = 0.34, 95%CI = 0.104−1.114, p = 0.075). The homogeneity of PR was associated with improved PFS/OS. This trial fails to demonstrate a significant increase in MPRR in patients treated with mFOLFOX6-bevacizumab but confirms PR as an important prognostic factor.

16.
Chem Rev ; 122(12): 10899-10969, 2022 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-34529918

RESUMEN

This is a critical review of artificial intelligence/machine learning (AI/ML) methods applied to battery research. It aims at providing a comprehensive, authoritative, and critical, yet easily understandable, review of general interest to the battery community. It addresses the concepts, approaches, tools, outcomes, and challenges of using AI/ML as an accelerator for the design and optimization of the next generation of batteries─a current hot topic. It intends to create both accessibility of these tools to the chemistry and electrochemical energy sciences communities and completeness in terms of the different battery R&D aspects covered.


Asunto(s)
Inteligencia Artificial , Aprendizaje Automático
17.
Commun Chem ; 5(1): 11, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36697877

RESUMEN

P2-Na2/3[Fe1/2Mn1/2]O2 layered oxide is a promising high energy density cathode material for sodium-ion batteries. However, one of its drawbacks is the poor long-term stability in the operating voltage window of 1.5-4.25 V vs Na+/Na that prevents its commercialization. In this work, additional light is shed on the origin of capacity fading, which has been analyzed using a combination of experimental techniques and theoretical methods. Electrochemical impedance spectroscopy has been performed on P2-Na2/3[Fe1/2Mn1/2]O2 half-cells operating in two different working voltage windows, one allowing and one preventing the high voltage phase transition occurring in P2-Na2/3[Fe1/2Mn1/2]O2 above 4.0 V vs Na+/Na; so as to unveil the transport properties at different states of charge and correlate them with the existing phases in P2-Na2/3[Fe1/2Mn1/2]O2. Supporting X-ray photoelectron spectroscopy experiments to elucidate the surface properties along with theoretical calculations have concluded that the formed electrode-electrolyte interphase is very thin and stable, mainly composed by inorganic species, and reveal that the structural phase transition at high voltage from P2- to "Z"/OP4-oxygen stacking is associated with a drastic increased in the bulk electronic resistance of P2-Na2/3[Fe1/2Mn1/2]O2 electrodes which is one of the causes of the observed capacity fading.

18.
Cuad. Hosp. Clín ; 62(2): 52-56, dic. 2021.
Artículo en Español | LILACS | ID: biblio-1358067

RESUMEN

Identificar el origen del retraso del crecimiento, baja masa magra y rendimiento deportivo asociado a estrés, falta de sueño, alteración de la imagen corporal y lesiones recurrentes, es un diagnóstico que lleva procesos en cada una de las áreas de especialización para la atención en pacientes. La composición corporal óptima es el resultado de una alimentación adecuada en cantidad, calidad, armonía, y sobre todo adecuación que es uno de los pilares del rendimiento deportivo que puede impactar en la mejora del crecimiento, desarrollo y de los compartimentos corporales. Componentes como el estrés, ansiedad, puede impactar en somatizar lesiones y alteración de la percepción de la imagen corporal, habilidades mentales auto exigencia y sueño. Todos esos factores se consideran en el presente caso para mejorar y optimizar el crecimiento y desarrollo de un deportista de alto rendimiento.(AU)


Asunto(s)
Masculino , Niño , Crecimiento y Desarrollo , Dieta , Rendimiento Atlético , Especialización , Composición Corporal , Índice de Masa Corporal , Diagnóstico
19.
Phys Chem Chem Phys ; 23(44): 25388-25400, 2021 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-34751284

RESUMEN

Largely inspired by nature, hierarchical porous materials are attractive for a wide range of applications as they provide a unique combination of transport and interfacial properties. Hierarchical macro-nanoporous metals (HMNPM) are of particular interest due to their high thermal and electrical conductivities, high volumetric macroporosity as well as their strong capillary forces, and large surface area due to their nanopores. However, tuning the porosity of HMNPMs remains challenging and often requires complex multi-step synthesis methods. Here we demonstrate that controlling the dealloying kinetics of close-to-eutectic alloys allows the selective tuning of the porosity of a hierarchical metal from tens of nanometers to hundreds of micrometers. This was demonstrated by dealloying the Cu-Mg-Zn alloy of close-to-eutectic composition to develop trimodal hierarchical macro-nanoporous copper with an impressive porosity of 94 vol% in the form of macroscopic self-supporting bulk samples. A combination of dealloying experiments and density functional theory calculations indicate that while selective corrosion of chemical phases in the Cu-Mg-Zn alloy is triggered according to their Volta potential, the kinetics can be altered by confinement and non-homogeneity effects. The obtained insights into the kinetics of close-to-eutectic alloy dealloying can be used to develop other hierarchical porous metals with tunable porosity and controlled shape.

20.
EMBO Rep ; 22(11): e51696, 2021 11 04.
Artículo en Inglés | MEDLINE | ID: mdl-34569685

RESUMEN

Neuroinflammation is a common feature of many neurodegenerative diseases. It fosters a dysfunctional neuron-microglia-astrocyte crosstalk that, in turn, maintains microglial cells in a perniciously reactive state that often enhances neuronal damage. The molecular components that mediate this critical communication are not fully explored. Here, we show that secreted frizzled-related protein 1 (SFRP1), a multifunctional regulator of cell-to-cell communication, is part of the cellular crosstalk underlying neuroinflammation. In mouse models of acute and chronic neuroinflammation, SFRP1, largely astrocyte-derived, promotes and sustains microglial activation, and thus a chronic inflammatory state. SFRP1 promotes the upregulation of components of the hypoxia-induced factor-dependent inflammatory pathway and, to a lower extent, of those downstream of the nuclear factor-kappa B. We thus propose that SFRP1 acts as an astrocyte-to-microglia amplifier of neuroinflammation, representing a potential valuable therapeutic target for counteracting the harmful effect of chronic inflammation in several neurodegenerative diseases.


Asunto(s)
Astrocitos , Microglía , Animales , Inflamación/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Microglía/metabolismo , Enfermedades Neuroinflamatorias
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