Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.123
Filtrar
Más filtros

Intervalo de año de publicación
1.
Proc Natl Acad Sci U S A ; 121(15): e2321255121, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38564632

RESUMEN

Omega-3 polyunsaturated fatty acids (PUFA) found primarily in fish oil have been a popular supplement for cardiovascular health because they can substantially reduce circulating triglyceride levels in the bloodstream to prevent atherosclerosis. Beyond this established extracellular activity, here, we report a mode of action of PUFA, regulating intracellular triglyceride metabolism and lipid droplet (LD) dynamics. Real-time imaging of the subtle and highly dynamic changes of intracellular lipid metabolism was enabled by a fluorescence lifetime probe that addressed the limitations of intensity-based fluorescence quantifications. Surprisingly, we found that among omega-3 PUFA, only docosahexaenoic acid (DHA) promoted the lipolysis in LDs and reduced the overall fat content by approximately 50%, and consequently helped suppress macrophage differentiation into foam cells, one of the early steps responsible for atherosclerosis. Eicosapentaenoic acid, another omega-3 FA in fish oil, however, counteracted the beneficial effects of DHA on lipolysis promotion and cell foaming prevention. These in vitro findings warrant future validation in vivo.


Asunto(s)
Aterosclerosis , Ácidos Grasos Omega-3 , Humanos , Lipólisis , Fluorescencia , Ácidos Grasos Omega-3/metabolismo , Aceites de Pescado/farmacología , Ácidos Docosahexaenoicos/metabolismo , Macrófagos/metabolismo , Triglicéridos
2.
Development ; 150(3)2023 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-36647820

RESUMEN

Self-organization of cells into higher-order structures is key for multicellular organisms, for example via repetitive replication of template-like founder cells or syncytial energids. Yet, very similar spatial arrangements of cell-like compartments ('protocells') are also seen in a minimal model system of Xenopus egg extracts in the absence of template structures and chromatin, with dynamic microtubule assemblies driving the self-organization process. Quantifying geometrical features over time, we show here that protocell patterns are highly organized with a spatial arrangement and coarsening dynamics similar to that of two-dimensional foams but without the long-range ordering expected for hexagonal patterns. These features remain invariant when enforcing smaller protocells by adding taxol, i.e. patterns are dominated by a single, microtubule-derived length scale. Comparing our data to generic models, we conclude that protocell patterns emerge by simultaneous formation of randomly assembling protocells that grow at a uniform rate towards a frustrated arrangement before fusion of adjacent protocells eventually drives coarsening. The similarity of protocell patterns to arrays of energids and cells in developing organisms, but also to epithelial monolayers, suggests generic mechanical cues to drive self-organized space compartmentalization.


Asunto(s)
Células Artificiales , Modelos Biológicos , Microtúbulos , Cromatina
3.
Circ Res ; 134(7): e34-e51, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38375634

RESUMEN

BACKGROUND: Many cardiovascular pathologies are induced by signaling through G-protein-coupled receptors via Gsα (G protein stimulatory α subunit) proteins. However, the specific cellular mechanisms that are driven by Gsα and contribute to the development of atherosclerosis remain unclear. METHODS: High-throughput screening involving data from single-cell and bulk sequencing were used to explore the expression of Gsα in atherosclerosis. The differentially expression and activity of Gsα were analyzed by immunofluorescence and cAMP measurements. Macrophage-specific Gsα knockout (Mac-GsαKO) mice were generated to study the effect on atherosclerosis. The role of Gsα was determined by transplanting bone marrow and performing assays for foam cell formation, Dil-ox-LDL (oxidized low-density lipoprotein) uptake, chromatin immunoprecipitation, and luciferase reporter assays. RESULTS: ScRNA-seq showed elevated Gnas in atherosclerotic mouse aorta's cholesterol metabolism macrophage cluster, while bulk sequencing confirmed increased GNAS expression in human plaque macrophage content. A significant upregulation of Gsα and active Gsα occurred in macrophages from human and mouse plaques. Ox-LDL could translocate Gsα from macrophage lipid rafts in short-term and promote Gnas transcription through ERK1/2 activation and C/EBPß phosphorylation via oxidative stress in long-term. Atherosclerotic lesions from Mac-GsαKO mice displayed decreased lipid deposition compared with those from control mice. Additionally, Gsα deficiency alleviated lipid uptake and foam cell formation. Mechanistically, Gsα increased the levels of cAMP and transcriptional activity of the cAMP response element binding protein, which resulted in increased expression of CD36 and SR-A1. In the translational experiments, inhibiting Gsα activation with suramin or cpGN13 reduced lipid uptake, foam cell formation, and the progression of atherosclerotic plaques in mice in vivo. CONCLUSIONS: Gsα activation is enhanced during atherosclerotic progression and increases lipid uptake and foam cell formation. The genetic or chemical inactivation of Gsα inhibit the development of atherosclerosis in mice, suggesting that drugs targeting Gsα may be useful in the treatment of atherosclerosis.


Asunto(s)
Aterosclerosis , Placa Aterosclerótica , Animales , Humanos , Ratones , Aterosclerosis/metabolismo , Células Espumosas/metabolismo , Lipoproteínas LDL/metabolismo , Macrófagos/metabolismo , Placa Aterosclerótica/patología , Transducción de Señal
4.
J Biol Chem ; 300(5): 107224, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38537695

RESUMEN

Impaired cholesterol efflux and/or uptake can influence arterial lipid accumulation leading to atherosclerosis. Here, we report that tripartite motif-containing protein 13 (TRIM13), a RING-type E3 ubiquitin ligase, plays a role in arterial lipid accumulation leading to atherosclerosis. Using molecular approaches and KO mouse model, we found that TRIM13 expression was induced both in the aorta and peritoneal macrophages (pMφ) of ApoE-/- mice in response to Western diet (WD) in vivo. Furthermore, proatherogenic cytokine interleukin-1ß also induced TRIM13 expression both in pMφ and vascular smooth muscle cells. Furthermore, we found that TRIM13 via ubiquitination and degradation of liver X receptor (LXR)α/ß downregulates the expression of their target genes ABCA1/G1 and thereby inhibits cholesterol efflux. In addition, TRIM13 by ubiquitinating and degrading suppressor of cytokine signaling 1/3 (SOCS1/3) mediates signal transducer and activator of transcription 1 (STAT1) activation, CD36 expression, and foam cell formation. In line with these observations, genetic deletion of TRIM13 by rescuing cholesterol efflux and inhibiting foam cell formation protects against diet-induced atherosclerosis. We also found that while TRIM13 and CD36 levels were increased, LXRα/ß, ABCA1/G1, and SOCS3 levels were decreased both in Mφ and smooth muscle cells of stenotic human coronary arteries as compared to nonstenotic arteries. More intriguingly, the expression levels of TRIM13 and its downstream signaling molecules were correlated with the severity of stenotic lesions. Together, these observations reveal for the first time that TRIM13 plays a crucial role in diet-induced atherosclerosis, and that it could be a potential drug target against this vascular lesion.


Asunto(s)
Aterosclerosis , Colesterol , Células Espumosas , Lipoproteínas LDL , Proteínas de Motivos Tripartitos , Ubiquitina-Proteína Ligasas , Animales , Humanos , Masculino , Ratones , Aterosclerosis/metabolismo , Aterosclerosis/patología , Aterosclerosis/genética , Transportador 1 de Casete de Unión a ATP/metabolismo , Transportador 1 de Casete de Unión a ATP/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1/metabolismo , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1/genética , Colesterol/metabolismo , Dieta Occidental/efectos adversos , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Células Espumosas/metabolismo , Células Espumosas/patología , Lipoproteínas LDL/metabolismo , Receptores X del Hígado/metabolismo , Receptores X del Hígado/genética , Ratones Noqueados para ApoE , Células RAW 264.7 , Factor de Transcripción STAT1/metabolismo , Factor de Transcripción STAT1/genética , Proteínas de Motivos Tripartitos/genética , Proteínas de Motivos Tripartitos/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación
5.
Eur Heart J ; 45(4): 268-283, 2024 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-38036416

RESUMEN

BACKGROUND AND AIMS: Macrophage-derived foam cells play a causal role during the pathogenesis of atherosclerosis. P2Y6 receptor (P2Y6R) highly expressed has been considered as a disease-causing factor in atherogenesis, but the detailed mechanism remains unknown. This study aims to explore P2Y6R in regulation of macrophage foaming, atherogenesis, and its downstream pathways. Furthermore, the present study sought to find a potent P2Y6R antagonist and investigate the feasibility of P2Y6R-targeting therapy for atherosclerosis. METHODS: The P2Y6R expression was examined in human atherosclerotic plaques and mouse artery. Atherosclerosis animal models were established in whole-body P2Y6R or macrophage-specific P2Y6R knockout mice to evaluate the role of P2Y6R. RNA sequencing, DNA pull-down experiments, and proteomic approaches were performed to investigate the downstream mechanisms. High-throughput Glide docking pipeline from repurposing drug library was performed to find potent P2Y6R antagonists. RESULTS: The P2Y6R deficiency alleviated atherogenesis characterized by decreasing plaque formation and lipid deposition of the aorta. Mechanically, deletion of macrophage P2Y6R significantly inhibited uptake of oxidized low-density lipoprotein through decreasing scavenger receptor A expression mediated by phospholipase Cß/store-operated calcium entry pathways. More importantly, P2Y6R deficiency reduced the binding of scavenger receptor A to CALR, accompanied by dissociation of calreticulin and STIM1. Interestingly, thiamine pyrophosphate was found as a potent P2Y6R antagonist with excellent P2Y6R antagonistic activity and binding affinity, of which the pharmacodynamic effect and mechanism on atherosclerosis were verified. CONCLUSIONS: Macrophage P2Y6R regulates phospholipase Cß/store-operated calcium entry/calreticulin signalling pathway to increase scavenger receptor A protein level, thereby improving foam cell formation and atherosclerosis, indicating that the P2Y6R may be a potential therapeutic target for intervention of atherosclerotic diseases using P2Y6R antagonists including thiamine pyrophosphate.


Asunto(s)
Aterosclerosis , Células Espumosas , Receptores Purinérgicos P2 , Humanos , Ratones , Animales , Células Espumosas/metabolismo , Células Espumosas/patología , Calcio/metabolismo , Calreticulina/metabolismo , Calreticulina/farmacología , Proteómica , Tiamina Pirofosfato/metabolismo , Tiamina Pirofosfato/farmacología , Aterosclerosis/genética , Macrófagos/metabolismo , Lipoproteínas LDL/metabolismo , Receptores Depuradores/metabolismo , Ratones Noqueados , Fosfolipasas/metabolismo , Fosfolipasas/farmacología
6.
Am J Physiol Cell Physiol ; 326(5): C1398-C1409, 2024 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-38525540

RESUMEN

Diabetes is one of the most prevalent diseases worldwide. In recent decades, type-2 diabetes has become increasingly common, particularly in younger individuals. Diabetes leads to many vascular complications, including atherosclerosis. Atherosclerosis is a cardiovascular disease characterized by lipid-rich plaques within the vasculature. Plaques develop over time, restricting blood flow, and can, therefore, be the underlying cause of major adverse cardiovascular events, including myocardial infarction and stroke. Diabetes and atherosclerosis are intrinsically linked. Diabetes is a metabolic syndrome that accelerates atherosclerosis and increases the risk of developing other comorbidities, such as diabetes-associated atherosclerosis (DAA). Gold standard antidiabetic medications focus on attenuating hyperglycemia. Though recent evidence suggests that glucose-lowering drugs may have broader applications, beyond diabetes management. This review mainly evaluates the role of glucagon-like peptide-1 receptor agonists (GLP-1 RAs), such as liraglutide and semaglutide in DAA. These drugs mimic gut hormones (incretins), which inhibit glucagon secretion while stimulating insulin secretion, thus improving insulin sensitivity. This facilitates delayed gastric emptying and increased patient satiety; hence, they are also indicated for the treatment of obesity. GLP-1 RAs have significant cardioprotective effects, including decreasing low-density lipoprotein (LDL) cholesterol and triglycerides levels. Liraglutide and semaglutide have specifically been shown to decrease cardiovascular risk. Liraglutide has displayed a myriad of antiatherosclerotic properties, with the potential to induce plaque regression. This review aims to address how glucose-lowering medications can be applied to treat diseases other than diabetes. We specifically focus on how nanomedicines can be used for the site-specific delivery of antidiabetic medicines for the treatment of diabetes-associated atherosclerosis.


Asunto(s)
Aterosclerosis , Diabetes Mellitus Tipo 2 , Hipoglucemiantes , Humanos , Aterosclerosis/tratamiento farmacológico , Aterosclerosis/metabolismo , Hipoglucemiantes/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Animales , Receptor del Péptido 1 Similar al Glucagón/agonistas , Receptor del Péptido 1 Similar al Glucagón/metabolismo , Glucemia/metabolismo , Glucemia/efectos de los fármacos , Sistemas de Liberación de Medicamentos/métodos
7.
J Lipid Res ; 65(2): 100496, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38185217

RESUMEN

Pulmonary alveolar proteinosis (PAP) is a life-threatening, rare lung syndrome for which there is no cure and no approved therapies. PAP is a disease of lipid accumulation characterized by alveolar macrophage foam cell formation. While much is known about the clinical presentation, there is a paucity of information regarding temporal changes in lipids throughout the course of disease. Our objectives were to define the detailed lipid composition of alveolar macrophages in PAP patients at the time of diagnosis and during treatment. We performed comprehensive mass spectrometry to profile the lipid signature of alveolar macrophages obtained from three independent mouse models of PAP and from PAP and non-PAP patients. Additionally, we quantified changes in macrophage-associated lipids during clinical treatment of PAP patients. We found remarkable variations in lipid composition in PAP patients, which were consistent with data from three independent mouse models. Detailed lipidomic analysis revealed that the overall alveolar macrophage lipid burden inversely correlated with clinical improvement and response to therapy in PAP patients. Specifically, as PAP patients experienced clinical improvement, there was a notable decrease in the total lipid content of alveolar macrophages. This crucial observation suggests that the levels of these macrophage-associated lipids can be utilized to assess the efficacy of treatment. These findings provide valuable insights into the dysregulated lipid metabolism associated with PAP, offering the potential for lipid profiling to serve as a means of monitoring therapeutic interventions in PAP patients.


Asunto(s)
Proteinosis Alveolar Pulmonar , Animales , Ratones , Humanos , Proteinosis Alveolar Pulmonar/tratamiento farmacológico , Proteinosis Alveolar Pulmonar/diagnóstico , Proteinosis Alveolar Pulmonar/metabolismo , Macrófagos Alveolares , Pulmón/metabolismo , Macrófagos/metabolismo , Lípidos
8.
J Cell Mol Med ; 28(7): e18177, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38494843

RESUMEN

Atherosclerosis, a chronic inflammatory disease of aorta, remains the major cause of morbidity and mortality among cardiovascular disease patients. Macrophage foam cell formation and inflammation are critically involved in early stages of atherosclerosis, hence chemopreventive targeting of foam cell formation by nutraceuticals may be a promising approach to curbing the progression of atherosclerosis. However, many nutraceuticals including berberine and ginkgetin have low stability, tissue/cell penetration and bioavailability resulting in inadequate chemotherapeutic effects of these nutraceuticals. We have used avocado-derived extracellular vesicles (EV) isolated from avocado (EVAvo ) as a novel carrier of nutraceuticals, in a strategy to alleviate the build-up of macrophage foam cells and expression of inflammatory genes. Our key findings are: (i) Avocado is a natural source of plant-derived EVs as shown by the results from transmission electron microscopy, dynamic light scattering and NanoBrook Omni analysis and atomic force microscopy; (ii) EVAvo are taken up by macrophages, a critical cell type in atherosclerosis; (iii) EVAvo can be loaded with high amounts of ginkgetin and berberine; (iv) ginkgetin plus berberine-loaded EVAvo (EVAvo(B+G) ) suppress activation of NFκB and NLRP3, and inhibit expression of pro-inflammatory and atherogenic genes, specifically Cd36, Tnfα, Il1ß and Il6; (v) EVAvo(B+G) attenuate oxidized low-density lipoprotein (oxLDL)-induced macrophage foam cell formation and (vi) EVAvo(B+G) inhibit oxLDL uptake but not its cell surface binding during foam cell formation. Overall, our results suggest that using EVAvo as a natural carrier of nutraceuticals may improve strategies to curb the progression of atherosclerosis by limiting inflammation and pro-atherogenic responses.


Asunto(s)
Aterosclerosis , Berberina , Biflavonoides , Persea , Humanos , Células Espumosas , Berberina/farmacología , Macrófagos , Aterosclerosis/tratamiento farmacológico , Aterosclerosis/prevención & control , Lipoproteínas LDL
9.
Pflugers Arch ; 476(1): 59-74, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37910205

RESUMEN

The formation of foam cells, lipid-loaded macrophages, is the hallmark event of atherosclerosis. Since cigarette smoking is a risk factor for developing atherosclerosis, the current study investigated the effects of cigarette smoke extract (CSE) on different events like expressions of genes involved in lipid influx and efflux, lipophagy, etc., that play vital roles in foam cell formation. The accumulation of lipids after CSE treatment U937 macrophage cells was examined by staining lipids with specific dyes: Oil red O and BODIPY493/503. Results showed an accumulation of lipids in CSE-treated cells, confirming foam cell formation by CSE treatment. To decipher the mechanism, the levels of CD36, an ox-LDL receptor, and ABCA1, an exporter of lipids, were examined in CSE-treated and -untreated U937 cells by real-time PCR and immunofluorescence analysis. Consistent with lipid accumulation, an increased level of CD36 and a reduction in ABCA1 were observed in CSE-treated cells. Moreover, CSE treatment caused inhibition of lipophagy-mediated lipid degradation by blocking lipid droplets (LDs)-lysosome fusion and increasing the lysosomal pH. CSE also impaired mitochondrial lipid oxidation. Thus, the present study demonstrates that CSE treatment affects lipid homeostasis by altering its influx and efflux, lysosomal degradation, and mitochondrial utilization, leading to the formation of lipid-loaded foam cells. Moreover, the current study also showed that the leucine supplement caused a significant reduction of CSE-induced foam cell formation in vitro. Thus, the current study provides insight into CS-induced atherosclerosis and an agent to combat the disease.


Asunto(s)
Aterosclerosis , Fumar Cigarrillos , Humanos , Células Espumosas/metabolismo , Lipoproteínas LDL/metabolismo , Lipoproteínas LDL/farmacología , Gotas Lipídicas/metabolismo , Células U937 , Aterosclerosis/metabolismo
10.
Mol Med ; 30(1): 38, 2024 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-38493291

RESUMEN

BACKGROUND: Macrophage-derived extracellular vesicle (macrophage-EV) is highly studied for its regulatory role in atherosclerosis (AS). Our current study tried to elucidate the possible role of macrophage-EV loaded with small interfering RNA against high-mobility group box 1 (siHMGB1) affecting atherosclerotic plaque formation. METHODS: In silico analysis was performed to find critical factors in mouse atherosclerotic plaque formation. EVs secreted by RAW 264.7 cells were collected by ultracentrifugation and characterized, followed by the preparation of macrophage-EV-loaded siHMGB1 (macrophage-EV/siHMGB1). ApoE-/- mice were used to construct an AS mouse model by a high-fat diet, followed by injection of macrophage-EV/siHMGB1 to assess the in vivo effect of macrophage-EV/siHMGB1 on AS mice. RAW264.7 cells were subjected to ox-LDL, LPS or macrophage-EV/siHMGB1 for analyzing the in vitro effect of macrophage-EV/siHMGB1 on macrophage pyrophosis and inflammation. RESULTS: In silico analysis found that HMGB1 was closely related to the development of AS. Macrophage-EV/siHMGB could inhibit the release of HMGB1 from macrophages to outside cells, and the reduced HMGB1 release could inhibit foam cell formation. Besides, macrophage-EV/siHMGB also inhibited the LPS-induced Caspase-11 activation, thus inhibiting macrophage pyroptosis and preventing atherosclerotic plaque formation. CONCLUSION: Our results proved that macrophage-EV/siHMGB could inhibit foam cell formation and suppress macrophage pyroptosis, finally preventing atherosclerotic plaque formation in AS mice.


Asunto(s)
Aterosclerosis , Vesículas Extracelulares , Proteína HMGB1 , Placa Aterosclerótica , Animales , Ratones , Apolipoproteínas E/genética , Aterosclerosis/genética , Caspasas , Regulación hacia Abajo , Proteína HMGB1/genética , Lipopolisacáridos/farmacología , Macrófagos , Piroptosis
11.
Biochem Biophys Res Commun ; 708: 149788, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38518720

RESUMEN

Atherosclerosis (AS) is the underlying cause of many severe vascular diseases and is primarily characterized by abnormal lipid metabolism. Paeonol (Pae), a bioactive compound derived from Paeonia Suffruticosa Andr., is recognized for its significant role in reducing lipid accumulation. Our research objective is to explore the link between lipid buildup in foam cells originating from macrophages and the process of ferroptosis, and explore the effect and mechanism of Pae on inhibiting AS by regulating ferroptosis. In our animal model, ApoE-deficient mice, which were provided with a high-fat regimen to provoke atherosclerosis, were administered Pae. The treatment was benchmarked against simvastatin and ferrostatin-1. The results showed that Pae significantly reduced aortic ferroptosis and lipid accumulation in the mice. In vitro experiments further demonstrated that Pae could decrease lipid accumulation in foam cells induced by oxidized low-density lipoprotein (LDL) and challenged with the ferroptosis inducer erastin. Crucially, the protective effect of Pae against lipid accumulation was dependent on the SIRT1/NRF2/GPX4 pathway, as SIRT1 knockdown abolished this effect. Our findings suggest that Pae may offer a novel therapeutic approach for AS by inhibiting lipid accumulation through the suppression of ferroptosis, mediated by the SIRT1/NRF2/GPX4 pathway. Such knowledge has the potential to inform the creation of novel therapeutic strategies aimed at regulating ferroptosis within the context of atherosclerosis.


Asunto(s)
Acetofenonas , Aterosclerosis , Ferroptosis , Animales , Ratones , Células Espumosas , Factor 2 Relacionado con NF-E2 , Sirtuina 1 , Macrófagos , Aterosclerosis/tratamiento farmacológico , Transducción de Señal
12.
Small ; 20(11): e2305120, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37926783

RESUMEN

To reduce electromagnetic interference and noise pollution within communication base stations and servers, it is necessary for electromagnetic wave absorption (EWA) materials to transition from coating to multifunctional devices. Up to now, the stable and effective integration of multiple functions into one material by a simple method has remained a large challenge. Herein, a foam-type microwave absorption device assembled with multicomponent organic matter and graphite powder is synthesized by a universal combination process. Melamine and phenolic aldehyde amine work as the skeleton and cementing compound, respectively, in which graphite is embedded in the cementing compound interconnected into the mesoscopic 3D electric conductive and heat conductive network. Interestingly, the prepared flexible graphite/melamine foam (CMF) delivers a great EWA performance, with a great effective absorption bandwidth of 9.8 GHz, ultrathin thickness of 2.60 mm, and a strong absorption reflection loss of -41.7 dB. Moreover, the CMF possesses porosity and flexibility, endowing it with sound absorption ability. The CMF is unique in its integration of EWA, heat conduction, sound absorption, and mechanical robustness, as well as its cost-effective and scalable manufacturing. These attributes make CMF promising as a multifunctional device widely used in communication base stations, servers, and chips protection.

13.
Small ; : e2405357, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39115110

RESUMEN

Sodium metal is regarded as one of the most promising anode materials due to its high theoretical capacity (1166 mAh g-1) and low redox potential (-2.714 V vs standard hydrogen electrode). However, the practical application of sodium metal is hindered by the formation of dendrites during Na stripping and plating, which can degrade performance and cause potential safety hazards. To address this issue, previous work focuses on leveraging either 3D current collectors or liquid metal modification on current collectors. In this work, both strategies are simultaneously leveraged to design a 3D Cu foam with liquid metal modification (LM@Cu) for dendrite-free sodium plating. The 3D configuration of Cu effectively reduces local current density and evenly distributes electric fields, while the introduction of liquid metal enhances the sodiophilicity of Cu to lower the nucleation barrier for sodium, thereby promoting its uniform plating. As a result, symmetric cells of Na with LM@Cu maintain stable cycling for over 2800 h. Additionally, full cells comprising Na-LM@Cu and Na3V2(PO4)3 sustain 97.5% of the capacity upon 1000 cycles, underscoring the great potentiality of liquid metal-mediated 3D current collectors in energy storage.

14.
Small ; : e2401465, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38750613

RESUMEN

Lithium (Li) metal batteries have attracted considerable research attention due to their exceptionally high theoretical capacity. However, the commercialization of Li metal batteries faces challenges, primarily attributed to uncontrolled growth of Li dendrites, which raises safety concerns and lowers coulombic efficiency. To mitigate Li dendrites growth and attain dense Li deposition, the hybrid SiO2-Cu2O lithiophilic film applied to a 3D copper foam current collector is developed to regulate the interfacial properties for achieving even and dense Li deposition. The SiO2-Cu2O possesses strong Li+ trapping capability through strong lithiophilicity from Cu2O. Additionally, the SiO2-Cu2O enables uniform ion diffusion through the domain-limiting effect of the holes in the SiO2 layer, inducing an even and dense Li plating/stripping behavior at a large capacity. Furthermore, the SiO2 layer promotes the formation of an initial high inorganic content Solid Electrolyte Interphase (SEI) through selective preferential binding with anion and solvent molecules. When the SiO2-Cu2O@Li anode is coupled with a LiFePO4 (LFP) cathode, the resulting full cell exhibits superior cycling stability and rate performance. These results provide a facile approach to construct a lithiophilic current collector for practical Li metal anodes.

15.
Small ; 20(34): e2400796, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38607275

RESUMEN

Solar-driven interfacial evaporation (SDIE) is a highly promising approach to achieve sustainable desalination and tackle the global freshwater crisis. Despite advancements in this field, achieving balanced thermal localization and salt resistance remains a challenge. Herein, the study presents a 3D hierarchical porous ceramic platform for SDIE applications. The utilized alumina foam ceramics (AFCs) exhibit remarkable corrosion resistance and chemical stability, ensuring a prolonged operational lifespan in seawater or brines. The millimeter-scale air-filled pores in AFCs prevent thermal losses through conduction with bulk water, resulting in heat-localized interfaces. The hydrophilic nature of macroporous AFC skeletons facilitates rapid water replenishment on the evaporating surface for effective salt-resistant desalination. Benefiting from its self-radiation adsorption and side-assisted evaporation capabilities, the AFC-based evaporators exhibit high indoor evaporation rates of 2.99 and 3.54 kg m-2 h-1 under one-sided and three-sided illumination under 1.0 sun, respectively. The AFC-based evaporator maintains a high evaporation rate of ≈2.77 kg m-2 h-1 throughout the 21-day long-term test. Furthermore, it achieves a daily water productivity of ≈10.44 kg m-2 in outdoor operations. This work demonstrates the potential of 3D hierarchical porous ceramics in addressing the trade-off between heat localization and salt resistance, and contributes to the development of durable solar steam generators.

16.
Small ; 20(22): e2310597, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38143296

RESUMEN

The electrochemical denitrification of nitrate (NO3 -) in actual wastewater to nitrogen (N2) is an effective approach to reversing the current imbalance of the nitrogen cycle and the eutrophication of water. However, electrostatic repulsion between NO3 - and the cathode results in the low efficiency of NO3 - reduction reaction (NO3RR). Here, density functional theory (DFT) calculations are used as a theoretical guide to design a Pd cluster-loaded multivalent Cu foam (Pd/Cu2O-CF) electrocatalyst, which achieves a splendid 97.8% NO3 - removal rate, 97.9% N2 selectivity, 695.5 mg N g-1 Pd h-1 reduction efficiency, and 60.0% Faradaic efficiency at -1.3 V versus SCE. The projected density of states (pDOS) indicates that NO3 - and Pd/Cu2O-CF are bonded via strong complexation between the O 2p (in NO3 -) and Cu 3d (in Cu2O) with the input of voltage, which reduces the electrostatic repulsion and enhances the enrichment of NO3 - on the cathode. In-situ characterizations demonstrate that Pd[H] can reduce Cu2O to Cu, and subsequently Cu reduces NO3 - to nitrite (NO2 -) accompanied by in situ reconfiguration of multivalent Cu foam. NO2 - is then transferred to the surface of Pd clusters by the cascade catalysis and accelerates the breaking of N─O bonds to form Pd─N, and eventually achieves the N≡N bond formation.

17.
Small ; 20(21): e2308320, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38105422

RESUMEN

The urgent need for the development of micro-thin shields against electromagnetic interference (EMI) has sparked interest in MXene materials owing to their metallic electrical conductivity and ease of film processing. Meanwhile, postprocessing treatments can potentially exert profound impacts on their shielding effectiveness (SE). This work comprehensively compares two reduction methods, hydrazine versus thermal, to fabricate foamed titanium carbonitride (Ti3CNTx) MXene films for efficient EMI shielding. Upon treatment of ≈ 100 µm-thick MXene films, gaseous transformations of oxygen-containing surface groups induce highly porous structures (up to ≈ 74.0% porosity). The controlled application of hydrazine and heat allows precise regulation of the reduction processes, enabling tailored control over the morphology, thickness, chemistry, and electrical properties of the MXene films. Accordingly, the EMI SE values are theoretically and experimentally determined. The treated MXene films exhibit significantly enhanced SE values compared to the pristine MXene film (≈ 52.2 dB), with ≈ 38% and ≈ 83% maximum improvements for the hydrazine and heat-treated samples, respectively. Particularly, heat treatment is more effective in terms of this enhancement such that an SE of 118.4 dB is achieved at 14.3 GHz, unprecedented for synthetic materials. Overall, the findings of this work hold significant practical implications for advancing high-performance, non-metallic EMI shielding materials.

18.
Small ; 20(24): e2309130, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38247181

RESUMEN

Various physical and chemical reaction processes occur in non-aqueous liquid systems, particularly in oil phase systems. Therefore, achieving efficient, accurate, controllable, and cost-effective movement and transfer of substances in the oil phase is crucial. Liquid-phase photothermal actuators (LPAs) are commonly used for material transport in liquid-phase systems due to their remote operability and precise control. However, existing LPAs typically rely on materials like hydrogels and flexible polymers, commonly unsuitable for non-aqueous liquids. Herein, a 3D porous poly(vinylidene fluoride) (PVDF)/Ti3C2Tx actuator is developed using a solvent displacement method. It demonstrates directional movement and controlled material transport in non-aqueous liquid systems. When subject to infrared light irradiation (2.0 W cm-2), the actuator achieves motion velocities of 7.3 and 6 mm s-1 vertically and horizontally, respectively. The actuator's controllable motion capability is primarily attributed to the foam's oil-wettable properties, 3D porous oil transport network, and the excellent photothermal conversion performance of Ti3C2Tx, facilitating thermal diffusion and the Marangoni effect. Apart from multidimensional directions, the actuator enables material delivery and obstacle avoidance by transporting and releasing target objects to a predetermined position. Hence, the developed controllable actuator offers a viable solution for effective motion control and material handling in non-aqueous liquid environments.

19.
Small ; 20(27): e2310530, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38317526

RESUMEN

Rechargeable aprotic Li-CO2 batteries have aroused worldwide interest owing to their environmentally friendly CO2 fixation ability and ultra-high specific energy density. However, its practical applications are impeded by the sluggish reaction kinetics and discharge product accumulation during cycling. Herein, a flexible composite electrode comprising CoSe2 nanoparticles embedded in 3D carbonized melamine foam (CoSe2/CMF) for Li-CO2 batteries is reported. The abundant CoSe2 clusters can not only facilitate CO2 reduction/evolution kinetics but also serve as Li2CO3 nucleation sites for homogeneous discharge product growth. The CoSe2/CMF-based Li-CO2 battery exhibits a large initial discharge capacity as high as 5.62 mAh cm-2 at 0.05 mA cm-2, a remarkably small voltage gap of 0.72 V, and an ultrahigh energy efficiency of 85.9% at 0.01 mA cm-2, surpassing most of the noble metal-based catalysts. Meanwhile, the battery demonstrates excellent cycling stability of 1620 h (162 cycles) at 0.02 mA cm-2 with an average overpotential of 0.98 V and energy efficiency of 85.4%. Theoretical investigations suggest that this outstanding performance is attributed to the suitable CO2/Li adsorption and low Li2CO3 decomposition energy. Moreover, flexible Li-CO2 pouch cell with CoSe2/CMF cathode displays stable power output under different bending deformations, showing promising potential in wearable electronic devices.

20.
Hum Reprod ; 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39190881

RESUMEN

STUDY QUESTION: Does hysterosalpingo-foam sonography (HyFoSy) prior to hysterosalpingography (HSG) or HSG prior to HyFoSy affect visible tubal patency when compared HSG or HyFoSy alone? SUMMARY ANSWER: Undergoing either HyFoSy or HSG prior to tubal patency testing by the alternative method does not demonstrate a significant difference in visible tubal patency when compared to HyFoSy or HSG alone. WHAT IS KNOWN ALREADY: HyFoSy and HSG are two commonly used visual tubal patency tests with a high and comparable diagnostic accuracy for evaluating tubal patency. These tests may also improve fertility, although the underlying mechanism is still not fully understood. One of the hypotheses points to a dislodgment of mucus plugs that may have disrupted the patency of the Fallopian tubes. STUDY DESIGN, SIZE, DURATION: This is a secondary analysis of the randomized controlled FOAM study, in which women underwent tubal patency testing by HyFoSy and HSG, randomized for order of the procedure. Participants either had HyFoSy first and then HSG, or vice versa. Here, we evaluate the relative effectiveness of tubal patency testing by HyFoSy or HSG prior to the alternative tubal patency testing method on visible tubal patency, compared to each method alone. PARTICIPANTS/MATERIALS, SETTING, METHODS: Infertile women aged between 18 and 41 years scheduled for tubal patency testing were eligible for participating in the FOAM study. Women with anovulatory cycles, endometriosis, or with a partner with male infertility were excluded. To evaluate the effect HyFoSy on tubal patency, we relied on HSG results by comparing the proportion of women with bilateral tubal patency visible on HSG in those who underwent and who did not undergo HyFoSy prior to their HSG (HyFoSy prior to HSG versus HSG alone). To evaluate the effect of HSG on tubal patency, we relied on HyFoSy results by comparing the proportion of women with bilateral tubal patency visible on HyFoSy in those who underwent and who did not undergo HSG prior to their HyFoSy (HSG prior to HyFoSy versus HyFoSy alone). MAIN RESULTS AND THE ROLE OF CHANCE: Between May 2015 and January 2019, we randomized 1160 women (576 underwent HyFoSy first followed by HSG, and 584 underwent HSG first followed by HyFoSy). Among the women randomized to HyFoSy prior to HSG, bilateral tubal patency was visible on HSG in 467/537 (87%) women, compared with 472/544 (87%) women who underwent HSG alone (risk difference 0.2%; 95% CI: -3.8% to 4.2%). Among the women randomized to HSG prior to HyFoSy, bilateral tubal patency was visible on HyFoSy in 394/471 (84%) women, compared with 428/486 (88%) women who underwent HyFoSy alone (risk difference -4.4%; 95% CI: -8.8% to 0.0%). LIMITATIONS, REASONS FOR CAUTION: The results of this secondary analysis should be interpreted as exploratory and cannot be regarded as definitive evidence. Furthermore, it has to be noted that pregnancy outcomes were not considered in this analysis. WIDER IMPLICATIONS OF THE FINDINGS: Tubal patency testing by either HyFoSy or HSG, prior to the alternative tubal patency testing method does not significantly affect visible tubal patency, when compared to alternative method alone. This suggests that both methods may have comparable abilities to dislodge mucus plugs in the Fallopian tubes. STUDY FUNDING/COMPETING INTEREST(S): The FOAM study was an investigator-initiated study, funded by ZonMw, a Dutch organization for Health Research and Development (project number 837001504). IQ Medical Ventures provided the ExEm®-FOAM kits free of charge. The funders had no role in study design, collection, analysis, or interpretation of the data. H.R.V. reports consultancy fees from Ferring. M.v.W. received a travel grant from Oxford University Press in the role of Deputy Editor for Human Reproduction and participates in a Data Safety and Monitoring Board as an independent methodologist in obstetrics studies in which she has no other role. M.v.W. is coordinating editor of Cochrane Fertility and Gynaecology. B.W.J.M. received an investigator grant from NHMRC (GNT1176437) and research funding from Merck KGaA. B.W.J.M. reports consultancy for Organon and Merck KGaA, and travel support from Merck KGaA. B.W.J.M. reports holding stocks of ObsEva. V.M. received research grants from Guerbet, Merck and Ferring and travel and speaker fees from Guerbet. The other authors do not report conflicts of interest. TRIAL REGISTRATION NUMBER: International Clinical Trials Registry Platform No. NTR4746.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA