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Gels (Basel, Switzerland) Jun 2024This review explores the recent progress on carbon xerogels (CXs) and highlights their development and use as efficient electrodes in organic electric double-layer... (Review)
Review
This review explores the recent progress on carbon xerogels (CXs) and highlights their development and use as efficient electrodes in organic electric double-layer capacitors (EDLCs). In addition, this work examines how the adjustment of synthesis parameters, such as pH, polymerization duration, and the reactant-to-catalyst ratio, crucially affects the structure and electrochemical properties of xerogels. The adaptability of xerogels in terms of modification of their porosity and structure plays a vital role in the improvement of EDLC applications as it directly influences the interaction between electrolyte ions and the electrode surface, which is a key factor in determining EDLC performance. The review further discusses the substantial effects of chemical activation with KOH on the improvement of the porous structure and specific surface area, which leads to notable electrochemical enhancements. This structural control facilitates improvement in ion transport and storage, which are essential for efficient EDLC charge-discharge (C-D) cycles. Compared with commercial activated carbons for EDLC electrodes, CXs attract interest for their superior surface area, lower electrical resistance, and stable performance across diverse C-D rates, which underscore their promising potential in EDLC applications. This in-depth review not only summarizes the advancements in CX research but also highlights their potential to expand and improve EDLC applications and demonstrate the critical role of their tunable porosity and structure in the evolution of next-generation energy storage systems.
PubMed: 38920946
DOI: 10.3390/gels10060400 -
Gels (Basel, Switzerland) Jun 2024In energy applications, the use of materials with hierarchical porous structures and large surface areas is essential for efficient charge storage. These structures... (Review)
Review
In energy applications, the use of materials with hierarchical porous structures and large surface areas is essential for efficient charge storage. These structures facilitate rapid electron and ion transport, resulting in high power density and quick charge/discharge capabilities. Carbon-based materials are extensively utilized due to their tunable properties, including pore sizes ranging from ultra- to macropores and surface polarity. Incorporating heteroatoms such as nitrogen, oxygen, sulfur, phosphorus, and boron modifies the carbon structure, enhancing electrocatalytic properties and overall performance. A hierarchical pore structure is necessary for optimal performance, as it ensures efficient access to the material's core. The microstructure of carbon materials significantly impacts energy storage, with factors like polyaromatic condensation, crystallite structure, and interlayer distance playing crucial roles. Carbon aerogels, derived from the carbonization of organic gels, feature a sponge-like structure with large surface area and high porosity, making them suitable for energy storage. Their open pore structure supports fast ion transfer, leading to high energy and power densities. Challenges include maintaining mechanical or structural integrity, multifunctional features, and scalability. This review provides an overview of the current progress in carbon-based aerogels for energy applications, discussing their properties, development strategies, and limitations, and offering significant guidance for future research requirements.
PubMed: 38920935
DOI: 10.3390/gels10060389 -
Microsystems & Nanoengineering 2024The introduction of flows within sessile droplets is highly effective for many lab-on-a-chip chemical and biomedical applications. However, generating such flows is...
The introduction of flows within sessile droplets is highly effective for many lab-on-a-chip chemical and biomedical applications. However, generating such flows is difficult due to the typically small droplet volumes. Here, we present a simple, non-contact strategy to generate internal flows in sessile droplets for enhancing mixing and mass transport. The flows are driven by actuating a rigid substrate into oscillation with certain amplitude distributions without relying on the resonance of the droplet itself. Substrate oscillation characteristics and corresponding flow patterns are documented herein. Mixing indices and mass transfer coefficients of sessile droplets on the substrate surface are measured using optical and electrochemical methods. They demonstrate complete mixing within the droplets in 1.35 s and increases in mass transfer rates of more than seven times static values. Proof of concept was conducted with experiments of silver nanoparticle synthesis and with heavy metal ion sensing employing the sessile droplet as a microreactor for synthesis and an electrochemical cell for sensing. The degrees of enhancement of synthesis efficiency and detection sensitivity attributed to the internal flows are experimentally documented.
PubMed: 38919162
DOI: 10.1038/s41378-024-00714-4 -
Microbiome Jun 2024Microbial adaptation to salinity has been a classic inquiry in the field of microbiology. It has been demonstrated that microorganisms can endure salinity stress via...
BACKGROUND
Microbial adaptation to salinity has been a classic inquiry in the field of microbiology. It has been demonstrated that microorganisms can endure salinity stress via either the "salt-in" strategy, involving inorganic ion uptake, or the "salt-out" strategy, relying on compatible solutes. While these insights are mostly based on laboratory-cultured isolates, exploring the adaptive mechanisms of microorganisms within natural salinity gradient is crucial for gaining a deeper understanding of microbial adaptation in the estuarine ecosystem.
RESULTS
Here, we conducted metagenomic analyses on filtered surface water samples collected from a typical subtropical short residence-time estuary and categorized them by salinity into low-, intermediate-, and high-salinity metagenomes. Our findings highlighted salinity-driven variations in microbial community composition and function, as revealed through taxonomic and Clusters of Orthologous Group (COG) functional annotations. Through metagenomic binning, 127 bacterial and archaeal metagenome-assembled genomes (MAGs) were reconstructed. These MAGs were categorized as stenohaline-specific to low-, intermediate-, or high-salinity-based on the average relative abundance in one salinity category significantly exceeding those in the other two categories by an order of magnitude. Those that did not meet this criterion were classified as euryhaline, indicating a broader range of salinity tolerance. Applying the Boruta algorithm, a machine learning-based feature selection method, we discerned important genomic features from the stenohaline bacterial MAGs. Of the total 12,162 COGs obtained, 40 were identified as important features, with the "inorganic ion transport and metabolism" COG category emerging as the most prominent. Furthermore, eight COGs were implicated in microbial osmoregulation, of which four were related to the "salt-in" strategy, three to the "salt-out" strategy, and one to the regulation of water channel activity. COG0168, annotated as the Trk-type K transporter related to the "salt-in" strategy, was ranked as the most important feature. The relative abundance of COG0168 was observed to increase with rising salinity across metagenomes, the stenohaline strains, and the dominant Actinobacteriota and Proteobacteria phyla.
CONCLUSIONS
We demonstrated that salinity exerts influences on both the taxonomic and functional profiles of the microbial communities inhabiting the estuarine ecosystem. Our findings shed light on diverse salinity adaptation strategies employed by the estuarine microbial communities, highlighting the crucial role of the "salt-in" strategy mediated by Trk-type K transporters for microorganisms thriving under osmotic stress in the short residence-time estuary. Video Abstract.
Topics: Estuaries; Salinity; Metagenomics; Bacteria; Archaea; Metagenome; Adaptation, Physiological; Microbiota; Seawater; Water Microbiology
PubMed: 38918820
DOI: 10.1186/s40168-024-01817-w -
Brain Communications 2024While voltage-gated potassium channels have critical roles in controlling neuronal excitability, they also have non-ion-conducting functions. Kv8.1, encoded by the KCNV1...
While voltage-gated potassium channels have critical roles in controlling neuronal excitability, they also have non-ion-conducting functions. Kv8.1, encoded by the KCNV1 gene, is a 'silent' ion channel subunit whose biological role is complex since Kv8.1 subunits do not form functional homotetramers but assemble with Kv2 to modify its ion channel properties. We profiled changes in ion channel expression in amyotrophic lateral sclerosis patient-derived motor neurons carrying a superoxide dismutase 1(A4V) mutation to identify what drives their hyperexcitability. A major change identified was a substantial reduction of KCNV1/Kv8.1 expression, which was also observed in patient-derived neurons with C9orf72 expansion. We then studied the effect of reducing KCNV1/Kv8.1 expression in healthy motor neurons and found it did not change neuronal firing but increased vulnerability to cell death. A transcriptomic analysis revealed dysregulated metabolism and lipid/protein transport pathways in KCNV1/Kv8.1-deficient motor neurons. The increased neuronal vulnerability produced by the loss of KCNV1/Kv8.1 was rescued by knocking down Kv2.2, suggesting a potential Kv2.2-dependent downstream mechanism in cell death. Our study reveals, therefore, unsuspected and distinct roles of Kv8.1 and Kv2.2 in amyotrophic lateral sclerosis-related neurodegeneration.
PubMed: 38911266
DOI: 10.1093/braincomms/fcae202 -
Cell Death Discovery Jun 2024Ion channels are critical in enabling ion movement into and within cells and are important targets for pharmacological interventions in different human diseases. In...
Ion channels are critical in enabling ion movement into and within cells and are important targets for pharmacological interventions in different human diseases. In addition to their ion transport abilities, ion channels interact with signalling and scaffolding proteins, which affects their function, cellular positioning, and links to intracellular signalling pathways. The study of "channelosomes" within cells has the potential to uncover their involvement in human diseases, although this field of research is still emerging. LRRC8A is the gene that encodes a crucial protein involved in the formation of volume-regulated anion channels (VRACs). Some studies suggest that LRRC8A could be a valuable prognostic tool in different types of cancer, serving as a biomarker for predicting patients' outcomes. LRRC8A expression levels might be linked to tumour progression, metastasis, and treatment response, although its implications in different cancer types can be varied. Here, publicly accessible databases of cancer patients were systematically analysed to determine if a correlation between VRAC channel expression and survival rate exists across distinct cancer types. Moreover, we re-evaluated the impact of LRRC8A on cellular proliferation and migration in colon cancer via HCT116 LRRC8A-KO cells, which is a current topic of debate in the literature. In addition, to investigate the role of LRRC8A in cellular signalling, we conducted biotin proximity-dependent identification (BioID) analysis, revealing a correlation between VRAC channels and cell-cell junctions, mechanisms that govern cellular calcium homeostasis, kinases, and GTPase signalling. Overall, this dataset improves our understanding of LRRC8A/VRAC and explores new research avenues while identifying promising therapeutic targets and promoting inventive methods for disease treatment.
PubMed: 38909013
DOI: 10.1038/s41420-024-02032-0 -
Environmental Pollution (Barking, Essex... Jun 2024Freshwater salinization is an escalating global environmental issue that threatens freshwater biodiversity, especially fish populations. This study aims to uncover the...
Unraveling the molecular mechanisms of fish physiological response to freshwater salinization: A comparative multi-tissue transcriptomic study in a river polluted by potash mining.
Freshwater salinization is an escalating global environmental issue that threatens freshwater biodiversity, especially fish populations. This study aims to uncover the molecular basis of salinity physiological responses in a non-native minnow species (Phoxinus septimaniae x P. dragarum) exposed to saline effluents from potash mines in the Llobregat River, Barcelona, Spain. Employing high-throughput mRNA sequencing and differential gene expression analyses, brain, gills, and liver tissues collected from fish at two stations (upstream and downstream of saline effluent discharge) were examined. Salinization markedly influenced global gene expression profiles, with the brain exhibiting the most differentially expressed genes, emphasizing its unique sensitivity to salinity fluctuations. Pathway analyses revealed the expected enrichment of ion transport and osmoregulation pathways across all tissues. Furthermore, tissue-specific pathways associated with stress, reproduction, growth, immune responses, methylation, and neurological development were identified in the context of salinization. Rigorous validation of RNA-seq data through quantitative PCR (qPCR) underscored the robustness and consistency of our findings across platforms. This investigation unveils intricate molecular mechanisms steering salinity physiological response in non-native minnows confronting diverse environmental stressors. This comprehensive analysis sheds light on the underlying genetic and physiological mechanisms governing fish physiological response in salinity-stressed environments, offering essential knowledge for the conservation and management of freshwater ecosystems facing salinization.
PubMed: 38906407
DOI: 10.1016/j.envpol.2024.124400 -
Journal of the American Heart... Jul 2024ELMSAN1 (ELM2-SANT domain-containing scaffolding protein 1) is a newly identified scaffolding protein of the MiDAC (mitotic deacetylase complex), playing a pivotal role...
BACKGROUND
ELMSAN1 (ELM2-SANT domain-containing scaffolding protein 1) is a newly identified scaffolding protein of the MiDAC (mitotic deacetylase complex), playing a pivotal role in early embryonic development. Studies on knockout mice showed that its absence results in embryo lethality and heart malformation. However, the precise function of ELMSAN1 in heart development and formation remains elusive. To study its potential role in cardiac lineage, we employed human-induced pluripotent stem cells (hiPSCs) to model early cardiogenesis and investigated the function of ELMSAN1.
METHODS AND RESULTS
We generated -deficient hiPSCs through knockdown and knockout techniques. During cardiac differentiation, depletion inhibited pluripotency deactivation, decreased the expression of cardiac-specific markers, and reduced differentiation efficiency. The impaired expression of genes associated with contractile sarcomere structure, calcium handling, and ion channels was also noted in -deficient cardiomyocytes derived from hiPSCs. Additionally, through a series of structural and functional assessments, we found that -null hiPSC cardiomyocytes are immature, exhibiting incomplete sarcomere Z-line structure, decreased calcium handling, and impaired electrophysiological properties. Of note, we found that the cardiac-specific role of ELMSAN1 is likely associated with histone H3K27 acetylation level. The transcriptome analysis provided additional insights, indicating maturation reduction with the energy metabolism switch and restored cell proliferation in knockout cardiomyocytes.
CONCLUSIONS
In this study, we address the significance of the direct involvement of ELMSAN1 in the differentiation and maturation of hiPSC cardiomyocytes. We first report the impact of ELMSAN1 on multiple aspects of hiPSC cardiomyocyte generation, including cardiac differentiation, sarcomere formation, calcium handling, electrophysiological maturation, and proliferation.
Topics: Myocytes, Cardiac; Induced Pluripotent Stem Cells; Cell Differentiation; Humans; Sarcomeres; Acetylation; Calcium Signaling; Cells, Cultured; Histones
PubMed: 38904247
DOI: 10.1161/JAHA.124.034816 -
RSC Advances Jun 2024With the increasing application of lithium-ion batteries, the demand for high energy density, high-rate performance and high stability lithium-ion batteries is becoming...
With the increasing application of lithium-ion batteries, the demand for high energy density, high-rate performance and high stability lithium-ion batteries is becoming more and more urgent. TiCO MXene, as a two-dimensional material with multilayer atomic structure and multiple active sites, has great advantages in lithium-ion battery electrode materials. However, the original TiCO MXene has been unable to meet the requirements of lithium-ion batteries due to its semiconductor properties. Doping is an effective means to regulate the conductivity and electrochemical properties of TiCO and improve the capacity of lithium-ion batteries and other energy storage devices. Hence, we use first-principles calculations to study the effect of V atom doping on the adsorption and diffusion of Li on the MXene surface. The density of states (DOS) and partial density of states (PDOS) of TiVCO and TiCO MXene indicated the transition of their conductive types from semiconductors to conductors. In addition, we observed that TiVCO has higher electrical conductivity and ion transport speed than the original TiCO MXene, and at the same time, Li atoms can be adsorbed well on the surface of MXene and show a lower diffusion energy barrier. Therefore, TiVCO is expected to become the anode material for the next generation of lithium-ion batteries and has good lithium storage performance.
PubMed: 38903673
DOI: 10.1039/d4ra03618b -
Colloids and Surfaces. B, Biointerfaces Jun 2024Responsiveness of liposomes to external stimuli, such as light, should allow a precise spatial and temporal control of release of therapeutic agents or ion transmembrane...
Responsiveness of liposomes to external stimuli, such as light, should allow a precise spatial and temporal control of release of therapeutic agents or ion transmembrane transport. Here, some aryl-azo derivatives of thymol are synthesized and embedded into liposomes from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine to obtain light-sensitive membranes whose photo-responsiveness, release behaviour, and permeability towards Cl ions are investigated. The hybrid systems are in-depth characterized by dynamic light scattering, atomic force microscopy and Raman spectroscopy. In liposomal bilayer the selected guests undergo reversible photoinduced isomerization upon irradiation with UV and visible light, alternately. Non-irradiated hybrid liposomes retain entrapped 5(6)-carboxyfluorescein (CF), slowing its spontaneous leakage, whereas UV-irradiation promotes CF release, due to guest trans-to-cis isomerization. Photoisomerization also influences membrane permeability towards Cl ions. Data processing, according to first-order kinetics, demonstrates that Cl transmembrane transport is enhanced by switching the guest from trans to cis but restored by back-switching the guest from cis to trans upon illumination with blue light. Finally, the passage of Cl ions across the bilayer can be fine-tuned by irradiation with light of longer λ and different light-exposure times. Fine-tuning the photo-induced structural response of the liposomal membrane upon isomerization is a promising step towards effective photo-dynamic therapy.
PubMed: 38901266
DOI: 10.1016/j.colsurfb.2024.114043