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1.
Nanoscale ; 16(15): 7559-7565, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38501607

RESUMO

The high-efficiency energy conversion process in organisms is usually carried out by organelles, proteins and membrane systems. Inspired by the cellular aerobic respiration process, we present an artificial electricity generation device, aimed at sustainable and efficient energy conversion using biological components, to demonstrate the feasibility of bio-inspired energy generation for renewable energy solutions. This approach bridges biological mechanisms and technology, offering a pathway to sustainable, biocompatible energy sources. The device features a mitochondria anode and oxygen-carrying red blood cells (RBCs) cathode, alongside a sandwich-structured sulfonated poly(ether ether ketone) and polyimide composite nanochannel for efficient proton transportation, mimicking cellular respiration. Achieving significant performance with 40 wt% RBCs, it produced a current density of 6.42 mA cm-2 and a maximum power density of 1.21 mW cm-2, maintaining over 50% reactivity after 8 days. This research underscores the potential of bio-inspired systems for advancing sustainable energy technologies.


Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Éteres , Eletrodos , Mitocôndrias , Eritrócitos
2.
Seizure ; 116: 87-92, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38523034

RESUMO

OBJECTIVES: The APC2 gene, encoding adenomatous polyposis coli protein-2, is involved in cytoskeletal regulation in neurons responding to endogenous extracellular signals and plays an important role in brain development. Previously, the APC2 variants have been reported to be associated with cortical dysplasia and intellectual disability. This study aims to explore the association between APC2 variants and epilepsy. METHODS: Whole-exome sequencing (WES) was performed in cases (trios) with epilepsies of unknown causes. The damaging effects of variants were predicted by protein modeling and in silico tools. Previously reported APC2 variants were reviewed to analyze the genotype-phenotype correlations. RESULTS: Four pairs of compound heterozygous missense variants were identified in four unrelated patients with epilepsy without brain malformation/intellectual disability. All variants presented no or low allele frequencies in the controls. The missense variants were predicted to be damaging by silico tools, and affect hydrogen bonding with surrounding amino acids or decreased protein stability. Patients with variants that resulted in significant changes in protein stability exhibited more severe and intractable epilepsy, whereas patients with variants that had minor effect on protein stability exhibited relatively mild phenotypes. The previously reported APC2 variants in patients with complex cortical dysplasia with other brain malformations-10 (CDCBM10; MIM: 618677) were all truncating variants; in contrast, the variants identified in epilepsy in this study were all missense variants, suggesting a potential genotype-phenotype correlation. SIGNIFICANCE: This study suggests that APC2 is potentially associated with epilepsy without brain malformation/intellectual disability. The genotype-phenotype correlation helps to understand the underlying mechanisms of phenotypic heterogeneity.


Assuntos
Epilepsia , Deficiência Intelectual , Malformações do Desenvolvimento Cortical , Transtornos do Neurodesenvolvimento , Humanos , Deficiência Intelectual/genética , Epilepsia/genética , Transtornos do Neurodesenvolvimento/genética , Mutação de Sentido Incorreto , Fenótipo , Proteínas do Citoesqueleto/genética
3.
BMC Genomics ; 25(1): 255, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38448893

RESUMO

BACKGROUND: Drug addiction is a serious problem worldwide and is influenced by genetic factors. The present study aimed to investigate the association between genetics and drug addiction among Han Chinese. METHODS: A total of 1000 Chinese users of illicit drugs and 9693 healthy controls were enrolled and underwent single nucleotide polymorphism (SNP)-based and haplotype-based association analyses via whole-genome genotyping. RESULTS: Both single-SNP and haplotype tests revealed associations between illicit drug use and several immune-related genes in the major histocompatibility complex (MHC) region (SNP association: log10BF = 15.135, p = 1.054e-18; haplotype association: log10BF = 20.925, p = 2.065e-24). These genes may affect the risk of drug addiction via modulation of the neuroimmune system. The single-SNP test exclusively reported genome-wide significant associations between rs3782886 (SNP association: log10BF = 8.726, p = 4.842e-11) in BRAP and rs671 (SNP association: log10BF = 7.406, p = 9.333e-10) in ALDH2 and drug addiction. The haplotype test exclusively reported a genome-wide significant association (haplotype association: log10BF = 7.607, p = 3.342e-11) between a region with allelic heterogeneity on chromosome 22 and drug addiction, which may be involved in the pathway of vitamin B12 transport and metabolism, indicating a causal link between lower vitamin B12 levels and methamphetamine addiction. CONCLUSIONS: These findings provide new insights into risk-modeling and the prevention and treatment of methamphetamine and heroin dependence, which may further contribute to potential novel therapeutic approaches.


Assuntos
Metanfetamina , Transtornos Relacionados ao Uso de Substâncias , Humanos , Estudo de Associação Genômica Ampla , Haplótipos , Polimorfismo de Nucleotídeo Único , Transtornos Relacionados ao Uso de Substâncias/genética , Vitamina B 12 , China , Aldeído-Desidrogenase Mitocondrial
4.
Small ; : e2309128, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38308414

RESUMO

The osmotic energy conversion properties of biomimetic light-stimulated nanochannels have aroused great interest. However, the power output performance is limited by the low light-induced current and energy conversion efficiency. Here, nanochannel arrays with simultaneous modification of ZnO and di-tetrabutylammonium cis-bis(isothiocyanato)bis(2,20-bipyridyl-4,40-dicarboxylato) ruthenium (II) (N719) onto anodic aluminum oxide (AAO) to combine the nano-confined effect and heterojunction is designed, which demonstrate rectified ion transport behavior due to the asymmetric composition, structure and charge. High cation selectivity and ion flux contribute to the high power density of ≈7.33 W m-2 by mixing artificial seawater and river water. Under light irradiation, heterojunction promoted the production and separation of exciton, enhanced cation selectivity, and improved the utilization efficiency of osmotic energy, providing a remarkable power density of ≈18.49 W m-2 with an increase of 252% and total energy conversion efficiency of 30.43%. The work opens new insights into the biomimetic nanochannels for high-performance energy conversion.

5.
Small Methods ; : e2301558, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38308417

RESUMO

Nanofluidic membranes are currently being explored as potential candidates for osmotic energy harvesting. However, the development of high-performance nanofluidic membranes remains a challenge. In this study, the ultrathin MXene membrane (H-MXM) is prepared by ultrathin slicing and realize the ion horizontal transportation. The H-MXM membrane, with a thickness of only 3 µm and straight subnanometer channels, exhibits ultrafast ion transport capabilities resembling an "ion freeway". By mixing artificial seawater and river water, a power output of 93.6 W m-2 is obtained. Just as cell membranes have an ultrathin thickness that allows for excellent penetration, this straight nanofluidic membrane also possesses an ultrathin structure. This unique feature helps to shorten the ion transport path, leading to an increased ion transport rate and improveS performance in osmotic energy conversion.

6.
bioRxiv ; 2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38328235

RESUMO

Despite the development of various drug delivery technologies, there remains a significant need for vehicles that can improve targeting and biodistribution in "hard-to-penetrate" tissues. Some solid tumors, for example, are particularly challenging to penetrate due to their dense extracellular matrix (ECM). In this study, we have formulated a new family of rod-shaped delivery vehicles named Janus base nanopieces (Rod JBNps), which are more slender than conventional spherical nanoparticles, such as lipid nanoparticles (LNPs). These JBNp nanorods are formed by bundles of DNA-inspired Janus base nanotubes (JBNts) with intercalated delivery cargoes. To develop this novel family of delivery vehicles, we employed a computation-aided design (CAD) methodology that includes molecular dynamics and response surface methodology. This approach precisely and efficiently guides experimental designs. Using an ovarian cancer model, we demonstrated that JBNps markedly improve penetration into the dense ECM of solid tumors, leading to better treatment outcomes compared to FDA-approved spherical LNP delivery. This study not only successfully developed a rod-shaped delivery vehicle for improved tissue penetration but also established a CAD methodology to effectively guide material design.

7.
ACS Appl Mater Interfaces ; 16(4): 5019-5027, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38228189

RESUMO

The energy conversion in plant chloroplast is carried out by pumping protons into the thylakoid for driving ATP synthesis. Inspired by ion active transport in living organisms, we attempted to design an artificial ion pump induced by subnanoconfinement effects. This ionic device uses two polarity functional nanoporous films as ion-selective valves at both ends and UiO-66 metal-organic framework-filled microchannels as ion storage cavities. In the charging process, ions could be pumped into the central cavities by nanovalves, which produced an ion gradient 10 to 100 times higher than the bulk, and were trapped within the subnanocages by dehydration. In the discharging process, the enriched ions were rehydrated and slowly released by the surface charge of the nanovalves, producing a sustainable ion current. The ion storage efficiency of this nanofluidic device could be improved to 60.3%, and the release time of ion current was also prolonged by 1 order of magnitude. This work combines the active and passive transport of ions to realize fast storage and slow release of ionic current, which provides an ion gradient-mediated novel energy conversion strategy.

8.
J Affect Disord ; 347: 57-65, 2024 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-37995923

RESUMO

BACKGROUND: Child maltreatment can increase the risk of lifetime non-suicidal self-injury (NSSI) and suicidal self-injury (SSI), but there is limited knowledge regarding the differences of potentially psychological mechanisms between NSSI with and without SSI. METHODS: Participants, 3918 community-based Chinese young men aged 18-34 years in Chengdu, were included in this study. We investigated the association between depression, anxiety, psychosis, child maltreatment, adulthood traumatic events, impulsivity, alcohol dependence, drug abuse, and lifetime of NSSI among participants with and without SSI. Parallel mediation analysis was utilized to explore the mediators for the relation between child maltreatment and NSSI. RESULTS: The prevalence of lifetime NSSI was 6.1 % (95 % CI: 5.4 %-6.9 %) among young men. Anxiety and impulsivity partially mediated the effect of child maltreatment on NSSI either with (indirect effect: 51.2 %) or without SSI (indirect effect: 34.3 %). Depression was independently and significantly associated with only NSSI but not with NSSI+SSI. Alcohol dependence and psychosis were independently and significantly associated with NSSI+SSI and mediated the effect of child maltreatment on NSSI+SSI. LIMITATIONS: The cross-sectional survey data limits the robustness of the proof to the causal relationships. CONCLUSIONS: Anxiety and impulsivity are associated with NSSI either with or without SSI and partially mediate the effect of child maltreatment on NSSI. Depression is associated with only NSSI, while alcohol dependence and psychosis are only associated with NSSI+SSI. It could be crucial to improve treatment and recovery of alcohol dependence and psychosis for preventing young men engaged in NSSI from attempting SSI.


Assuntos
Experiências Adversas da Infância , Alcoolismo , Comportamento Autodestrutivo , Adulto , Humanos , Masculino , Ansiedade/epidemiologia , Ansiedade/psicologia , Estudos Transversais , Comportamento Impulsivo , Fatores de Risco , Comportamento Autodestrutivo/epidemiologia , Comportamento Autodestrutivo/psicologia , Ideação Suicida , Adolescente , Adulto Jovem
9.
Seizure ; 111: 172-177, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37657306

RESUMO

OBJECTIVES: The APC2 gene, encoding adenomatous polyposis coli protein-2, is involved in cytoskeletal regulation in neurons responding to endogenous extracellular signals and plays an important role in brain development. Previously, the APC2 variants have been reported to be associated with cortical dysplasia and intellectual disability. This study aims to explore the association between APC2 variants and epilepsy. METHODS: Whole-exome sequencing (WES) was performed in cases (trios) with epilepsies of unknown causes. The damaging effects of variants were predicted by protein modeling and in silico tools. Previously reported APC2 variants were reviewed to analyze the genotype-phenotype correlations. RESULTS: Four pairs of compound heterozygous missense variants were identified in four unrelated patients with epilepsy without brain malformation/intellectual disability. All variants presented no or low allele frequencies in the controls. The missense variants were predicted to be damaging by silico tools, and affect hydrogen bonding with surrounding amino acids or decreased protein stability. Patients with variants that resulted in significant changes in protein stability exhibited more severe and intractable epilepsy, whereas patients with variants that had minor effect on protein stability exhibited relatively mild phenotypes. The previously reported APC2 variants in patients with complex cortical dysplasia with other brain malformations-10 (CDCBM10; MIM: 618677) were all truncating variants; in contrast, the variants identified in epilepsy in this study were all missense variants, suggesting a potential genotype-phenotype correlation. SIGNIFICANCE: This study suggests that APC2 is potentially associated with epilepsy without brain malformation/intellectual disability. The genotype-phenotype correlation helps to understand the underlying mechanisms of phenotypic heterogeneity.


Assuntos
Epilepsia , Humanos , Proteínas do Citoesqueleto/genética , Epilepsia/genética , Mutação de Sentido Incorreto , Transtornos do Neurodesenvolvimento/genética , Fenótipo
10.
J Pharmacol Toxicol Methods ; 123: 107297, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37499956

RESUMO

INTRODUCTION: In the framework of the IMI2-NeuroDeRisk consortium, three in vitro electrophysiology assays were compared to improve preclinical prediction of seizure-inducing liabilities. METHODS: Two cell models, primary rat cortical neurons and human induced pluripotent stem cell (hiPSC)-derived glutamatergic neurons co-cultured with hiPSC-derived astrocytes were tested on two different microelectrode array (MEA) platforms, Maestro Pro (Axion Biosystems) and Multiwell-MEA-System (Multi Channel Systems), in three separate laboratories. Pentylenetetrazole (PTZ) and/or picrotoxin (PTX) were included in each plate as positive (n = 3-6 wells) and ≤0.2% DMSO was used as negative controls (n = 3-12 wells). In general, concentrations in a range of 0.1-30 µM were tested, anchored, when possible, on clinically relevant exposures (unbound Cmax) were tested. Activity thresholds for drug-induced changes were set at 20%. To evaluate sensitivity, specificity and predictivity of the cell models, seizurogenic responses were defined as changes in 4 or more endpoints. Concentration dependence trends were also considered. RESULTS: Neuronal activity of 33 compounds categorized as positive tool drugs, seizure-positive or seizure-negative compounds was evaluated. Acute drug effects (<60 min) were compared to baseline recordings. Time points < 15 min exhibited stronger, less variable responses to many of the test agents. For many compounds a reduction and cessation of neuronal activity was detected at higher test concentrations. There was not a single pattern of seizurogenic activity detected, even among tool compounds, likely due to different mechanisms of actions and/or off-target profiles. A post-hoc analysis focusing on changes indicative of neuronal excitation is presented. CONCLUSION: All cell models showed good sensitivity, ranging from 70 to 86%. Specificity ranged from 40 to 70%. Compared to more conventional measurements of evoked activity in hippocampal slices, these plate-based models provide higher throughput and the potential to study subacute responses. Yet, they may be limited by the random, spontaneous nature of their network activity.


Assuntos
Células-Tronco Pluripotentes Induzidas , Ratos , Humanos , Animais , Microeletrodos , Células Cultivadas , Convulsões/induzido quimicamente , Neurônios
11.
Small ; 19(37): e2301512, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37154221

RESUMO

The covalent organic frameworks (COFs) membrane with ordered and confined one-dimensional channel has been considered as a promising material to harvest the salinity gradient energy from the seawater and river water. However, the application of the COFs in the field of energy conversion still faces the challenges in membrane preparation. Herein, energy harvesting is achieved by taking advantage of a COFs membrane where TpDB-HPAN is synthesized via layer-by-layer self-assembly strategy at room temperature. The carboxy-rich TpDB COFs can be expediently assembled onto the substrate with an environmental-friendly method. The increased open-circuit voltage (Voc ) endows TpDB-HPAN membrane with a remarkable energy harvesting performance. More importantly, the application perspective is also illuminated by the cascade system. With the advantages of green synthesis, the TpDB-HPAN membrane can be considered as a low-cost and promising candidate for energy conversion.

12.
Small ; 18(35): e2203104, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35931455

RESUMO

Smart modulation of bioelectric signals is of great significance for the development of brain-computer interfaces, bio-computers, and other technologies. The regulation and transmission of bioelectrical signals are realized through the synergistic action of various ion channels in organisms. The bionic nanochannels, which have similar physiological working environment and ion rectification as their biological counterparts, can be used to construct ion rectifier bridges to modulate the bioelectric signals. Here, the artificial smart ionic rectifier bridge with light response is constructed by anodic aluminum oxide (AAO)/poly (spiropyran acrylate) (PSP) nanochannels. The output ion current of the rectifier bridge can be switched between "ON" and "OFF" states by irradiation with UV and visible (Vis) light, and the conversion efficiency (η) of the system in "ON" state is ≈70.5%. The controllable modulation of brain wave-like signal can be realized by ionic rectifier bridge. The ion transport properties and processes of ion rectifier bridges are explained using theoretical calculations based on Poisson-Nernst-Planck (PNP) equations. These findings have significant implications for the understanding of the intelligent ionic circuit and combination of artificial smart ionic channels to organisms, which provide new avenues for development of intelligent ion devices.


Assuntos
Ondas Encefálicas , Canais Iônicos , Transporte de Íons , Íons , Luz
13.
Small ; 18(20): e2107600, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35324064

RESUMO

Many materials with nanofluidic channels are exploited to achieve salinity gradient energy conversion. However, most materials are fragile, difficult to process, or only prepared into a limited size, which greatly restricts their practical application in the future. Herein, a covalent organic polymers membrane with high mechanical property and stability is fabricated, which can keep integrity in harsh conditions for up to 1 month. In addition, by using the sol-gel approach, a large-area membrane with an area of 26 × 26 cm is expediently fabricated in lab conditions. When the membrane is applied to salinity gradient energy conversion, the maximum output power density is up to 6.21 W m-2 . This work provides a simple method for the fabrication of large-area membrane for salinity gradient energy conversion in future real-world applications.


Assuntos
Polímeros , Salinidade , Eletricidade , Fenômenos Físicos
14.
J Med Chem ; 65(8): 6001-6016, 2022 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-35239336

RESUMO

3,3-Disubstituted oxetanes have been utilized as bioisosteres for gem-dimethyl and cyclobutane functionalities. We report the discovery of a novel class of oxetane indole-amine 2,3-dioxygenase (IDO1) inhibitors suitable for Q3W (once every 3 weeks) oral and parenteral dosing. A diamide class of IDO inhibitors was discovered through an automated ligand identification system (ALIS). Installation of an oxetane and fluorophenyl dramatically improved the potency. Identification of a biaryl moiety as an unconventional amide isostere addressed the metabolic liability of amide hydrolysis. Metabolism identification (Met-ID)-guided target design and the introduction of polarity resulted in the discovery of potent IDO inhibitors with excellent pharmacokinetic (PK) profiles in multiple species. To enable rapid synthesis of the key oxetane intermediate, a novel oxetane ring cyclization was also developed, as well as optimization of a literature route on kg scale. These IDO inhibitors may enable unambiguous proof-of-concept testing for the IDO1 inhibition mechanism for oncology.


Assuntos
Inibidores Enzimáticos , Éteres Cíclicos , Amidas , Ciclização , Inibidores Enzimáticos/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo
15.
ACS Nano ; 15(12): 19266-19274, 2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-34870410

RESUMO

Constructing nanofluidic diode nanochannels with an asymmetric structure for logic gate circuits has attracted extensive research interests. Currently, the preparation of a geometrically asymmetric nanochannel relies on cost-effective material-processing methods and has been hard to scale up, limiting the development of nanofluidic research. Herein, we introduce the idea of geometric tailoring to cut the MXene lamellar membrane in different shapes and investigate the ion transport behavior systematically. The ion rectification can be regulated by adjusting geometric factors such as the asymmetric ratio and height of the trapezoidal membrane. On the basis of the above-mentioned research on rectification characteristics, we further optimized the trapezoidal membrane into a triangular membrane on the macroscopic level and successfully applied it to logic circuits, realizing the logic operations of "AND" and "OR". It is worth mentioning that the shape of a macrocut triangular membrane is exactly the same as the symbol of an electronic diode, and the conduction and cutoff directions of the ionic current are also exactly the same as those of electronic diodes. Our finding provides a facile and general strategy for fabricating a macroscale geometric asymmetry nanochannel-based two-dimensional lamellar membrane and shows the potential applications in complex highly integrated ionic circuits.

16.
Toxicol Appl Pharmacol ; 430: 115725, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34536444

RESUMO

An effective in vitro screening assay to detect seizure liability in preclinical development can contribute to better lead molecule optimization prior to candidate selection, providing higher throughput and overcoming potential brain exposure limitations in animal studies. This study explored effects of 26 positive and 14 negative reference pharmacological agents acting through different mechanisms, including 18 reference agents acting on glutamate signaling pathways, in a brain slice assay (BSA) of adult rat to define the assay's sensitivity, specificity, and limitations. Evoked population spikes (PS) were recorded from CA1 pyramidal neurons of hippocampus (HPC) in the BSA. Endpoints for analysis were PS area and PS number. Most positive references (24/26) elicited a concentration-dependent increase in PS area and/or PS number. The negative references (14/14) had little effect on the PS. Moreover, we studied the effects of 15 reference agents testing positive in the BSA on spontaneous activity in E18 rat HPC neurons monitored with microelectrode arrays (MEA), and compared these effects to the BSA results. From these in vitro studies we conclude that the BSA provides 93% sensitivity and 100% specificity in prediction of drug-induced seizure liability, including detecting seizurogenicity by 3 groups of metabotropic glutamate receptor (mGluR) ligands. The MEA results seemed more variable, both quantitatively and directionally, particularly for endpoints capturing synchronized electrical activity. We discuss these results from the two models, comparing each with published results, and provide potential explanations for differences and future directions.


Assuntos
Convulsivantes/toxicidade , Potenciais Evocados/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Convulsões/induzido quimicamente , Testes de Toxicidade , Animais , Células Cultivadas , Feminino , Idade Gestacional , Ácido Glutâmico/metabolismo , Hipocampo/embriologia , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Técnicas In Vitro , Ligantes , Masculino , Neurônios/metabolismo , Ratos Sprague-Dawley , Ratos Wistar , Receptores de Glutamato Metabotrópico/metabolismo , Reprodutibilidade dos Testes , Medição de Risco , Convulsões/metabolismo , Convulsões/fisiopatologia , Transdução de Sinais
17.
Small ; 17(38): e2102880, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34405945

RESUMO

Ion storage structure widely exists in organisms, which is used to harvesting energy in environment and converting it into ion concentration gradient to maintain complex life activities. The construction of ion storage structures relies on isolating the biological body fluids by biofilm systems, which can also be regarded as local ions confinement. Mimicking this ions storage process, an "ion pool" structural ion storage device is proposed in this research by artificial ion nanochannels, which can transform the electric power into ion concentration gradient. It is consisted of micrometer-sized ions reservoir and nanosized ions filters. Ions can be isolated within the "pool" and performed ultrahigh ions enrichment or depletion behavior deviated from bulk. Through numerical simulation by Poisson-Nernst-Planck equations, "ion pool" structural device achieves nearly 20 000 rectification ratio with low surface charge. An "ion pool" structural ions storage device is also constructed with block copolymer and polyethylene terephthalate composite membranes, a super high rectification ratio of 3184.0 is achieved from the experiment, which is the highest reported so far. The ion storage efficiency of the device reaches 14.90%, which is an order of magnitude better than non-"ion pool" structural nanofluid devices.


Assuntos
Eletricidade , Simulação por Computador , Íons
18.
ACS Appl Mater Interfaces ; 13(34): 41159-41168, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34403239

RESUMO

As an important nanofluidic device, an artificial ion nanochannel could selectively transport ions inside its nanoconfinement space and the surface charge of the pore wall. Here, confinement effects were realized by tandem nanochannel units, which kept their cascade gaps less than 500 nm. Within these gaps, ionic conductance was governed by the surface charge density of the channel unit. Cations could be sufficiently selected and enriched within this confined space, which improves the cation transfer number of the system. Therefore, the tandem nanochannel system could greatly improve the diffusion potential and energy conversion efficiency in the salinity gradient power generation process. Poisson-Nernst-Planck equations were introduced to numerically simulate the ionic transport behavior and confirmed the experimental results. Finally, the gap confinement effect was introduced in the porous cellulose acetate membrane tandem nanochannel system, and a high output power density of 4.72 W/m2 and energy conversion efficiency of 42.22% were achieved under stacking seven channel units.

19.
ACS Appl Mater Interfaces ; 13(29): 35197-35206, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34266231

RESUMO

Nanoconfinement ion transport, similar to that of biological ion channels, has attracted widespread research interest and offers prospects for broad applications in energy conversion and nanofluidic diodes. At present, various methods were adopted to improve the rectification performance of nanofluidic diodes including geometrical, chemical, and electrostatic asymmetries. However, contributions of the confinement effects within the channels were neglected, which can be a crucial factor for ion rectification behavior. In this research, we report an "ion pool"-structured nanofluidic diode to improve the confinement effect of the system, which was constructed based on an anodic aluminum oxide (AAO) nanoporous membrane sandwiched between zeolitic imidazolate framework 8 (ZIF-8) and tungsten oxide (WO3) thin membranes. A high rectification ratio of 192 is obtained through this nanofluidic system due to ions could be enriched or depleted sufficiently within the ion pool. Furthermore, this high-rectification-ratio ion pool-structured nanofluidic diode possessed pH-responsive and excellent ion selectivity. We developed it as a pH-responsive power gating for a salinity gradient harvesting device by controlling the surface charge density of the ion pool nanochannel narrow ends with different pH values, and hence, the ionic gate is switched between On and Off states, with a gating ratio of up to 27, which exhibited 8 times increase than ZIF-8-AAO and AAO-WO3 composite membranes. Significantly, the peculiar ion pool structure can generate high rectification ratios due to the confinement effect, which then achieves high gating ratios. Such ion pool-structured nanochannels created new avenues to design and optimize nanofluidic diodes and boosted their applications in energy conversion areas.

20.
J Phys Chem Lett ; 12(23): 5587-5592, 2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34109791

RESUMO

The confinement effect of biological ion channels regulates the transport of molecules and ions due to angstrom-sized pores. The structure of the potassium channel has a selection region (3-4 Å), a cavity (10 Å), and a gated region, while ZIF-8 has intrinsic pores with a 3.4 Å aperture and an 11.6 Å cavity similar to those of the potassium channel. Inspired by this, we constructed the glass/ZIF-8 hybrid membrane through an electrochemical growth process to explore the kinetics of the ion transmembrane by I-V curves and electrochemical impedance spectroscopy. These complementary approaches yield highly correlated results that show that ion transportation of the ZIF-8 membrane follows Arrhenius behavior. The rates of ions are controlled by the transmembrane activation energy, in which the ionic charge and radius play an important role.


Assuntos
Imidazóis/farmacocinética , Estruturas Metalorgânicas/farmacocinética , Metais Alcalinoterrosos/farmacocinética , Nanotecnologia/métodos , Canais de Potássio/farmacocinética , Imidazóis/química , Canais Iônicos/química , Canais Iônicos/farmacocinética , Transporte de Íons/fisiologia , Cinética , Estruturas Metalorgânicas/química , Metais Alcalinoterrosos/química , Canais de Potássio/química
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