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1.
Biosensors (Basel) ; 13(1)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36671963

RESUMO

Metal-organic frameworks (MOFs)-based optical nanoprobes for luminescence and surface-enhanced Raman spectroscopy (SERS) applications have been receiving tremendous attention. Every element in the MOF structure, including the metal nodes, the organic linkers, and the guest molecules, can be used as a source to build single/multi-emission signals for the intended analytical purposes. For SERS applications, the MOF can not only be used directly as a SERS substrate, but can also improve the stability and reproducibility of the metal-based substrates. Additionally, the porosity and large specific surface area give MOF a sieving effect and target molecule enrichment ability, both of which are helpful for improving detection selectivity and sensitivity. This mini-review summarizes the advances of MOF-based optical detection methods, including luminescence and SERS, and also provides perspectives on future efforts.


Assuntos
Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Reprodutibilidade dos Testes , Metais/química , Análise Espectral Raman/métodos
2.
Chemosphere ; 315: 137692, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36596328

RESUMO

Metal pollution has raised negative impact on microbes, but little is known about the distribution and co-occurrence pattern of bacterial, fungal and archaeal communities along the soil profiles at multiple metal contamination sites. Here, we characterized the variations of metal concentrations and microbial communities with soil depth along five deep bores at the Tanghe Sewage Reservoir, a typical metal contamination area on the North China Plain. Co, Cd, Mg, Se, and Li were identified as the major contaminants in this area, and the pollution load index was 1.88, 1.54 and 1.62 in the shallow layer (0-0.6 m), deep layer (>2.0 m) and middle layer (0.6-2.0 m), respectively. The diversities and compositions of bacterial, archaeal and fungal communities varied significantly along the soil profiles. Deterministic process played a crucial role in shaping the difference of microbial community compositions among different soil layers, in which metal levels contributed more than soil physiochemical parameters. Furthermore, the interspecific co-occurrence network was most complex in the middle layer, indicating that metal pollution could decrease microbial network complexity. Bacterial keystone species in the co-occurrence networks showed both positive and negative correlations with polluted metals, whereas most archaeal and fungal keystone species were negatively related to multiple metals. These findings increased our understanding of distribution patterns, co-occurrence networks and environmental drivers of microbial communities in metal pollution soils.


Assuntos
Micobioma , Poluentes do Solo , Archaea , Solo/química , Poluentes do Solo/análise , Bactérias , Metais/farmacologia , Microbiologia do Solo
3.
J Chromatogr A ; 1689: 463772, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36610186

RESUMO

Algae toxins pose a severe threat to human health all over the world. In this study, magnetic metal/nitrogen-doped carbon nanotubes (M-NCNTs) were facilely synthesized based on one-step carbonization and applied for magnetic solid-phase extraction of okadaic acid (OA) from seawater followed by high performance liquid chromatographic tandem mass spectrometry (HPLC-MS/MS) analyses. Differences in the physicochemical properties of the three prepared materials (Fe/Co/Ni-NCNTs) were investigated to confirm the best extraction material. Among them, Ni-NCNTs demonstrated a faster extraction rate (10 min) and higher adsorption capacity (223.5 mg g-1), mainly due to the higher specific surface area, suitable pore structure and more abundant pyridine nitrogen ring. Under the optimal conditions, the calibration curve was linear over the range (1.0-800.0 pg mL-1) with good determination coefficients (R) of 0.9992. The limit of detection (LOD) obtained in multiple replicates was 0.4 pg mL-1. Three seawater samples were measured by the developed method, 12.3 pg mL-1 of OA was detected with a satisfying recovery (88.6%-106.7%) and acceptable repeatability (RSD ≤ 4.8%, n = 6). The results demonstrate that M-NCNTs materials are a promising candidate for magnetic solid-phase extraction. Benefiting from its high extraction and interference resistance, the established analytical method is expected to be extended to detect other marine environmental pollutions.


Assuntos
Nanotubos de Carbono , Humanos , Ácido Okadáico/análise , Nanotubos de Carbono/química , Espectrometria de Massas em Tandem/métodos , Nitrogênio , Água do Mar/química , Extração em Fase Sólida/métodos , Cromatografia Líquida de Alta Pressão , Metais , Fenômenos Magnéticos
4.
Nature ; 613(7945): 662-666, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36697865

RESUMO

Field emission of electrons underlies great advances in science and technology, ranging from signal processing at ever higher frequencies1 to imaging of the atomic-scale structure of matter2 with picometre resolution. The advancing of electron microscopy techniques to enable the complete visualization of matter on the native spatial (picometre) and temporal (attosecond) scales of electron dynamics calls for techniques that can confine and examine the field emission on sub-femtosecond time intervals. Intense laser pulses have paved the way to this end3,4 by demonstrating femtosecond confinement5,6 and sub-optical cycle control7,8 of the optical field emission9 from nanostructured metals. Yet the measurement of attosecond electron pulses has remained elusive. We used intense, sub-cycle light transients to induce optical field emission of electron pulses from tungsten nanotips and a weak replica of the same transient to directly investigate the emission dynamics in real time. Access to the temporal properties of the electron pulses rescattering off the tip surface, including the duration τ = (53 as ± 5 as) and chirp, and the direct exploration of nanoscale near fields open new prospects for research and applications at the interface of attosecond physics and nano-optics.


Assuntos
Luz , Nanoestruturas , Microscopia Eletrônica , Nanoestruturas/química , Metais
5.
Int J Mol Sci ; 24(2)2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36674772

RESUMO

Biometals are all metal ions that are essential for all living organisms. About 40% of all enzymes with known structures require biometals to function correctly. The main target of damage by biometals is the central nervous system (CNS). Biometal dysregulation (metal deficiency or overload) is related to pathological processes. Chronic occupational and environmental exposure to biometals, including iron and copper, is related to an increased risk of developing Parkinson's disease (PD). Indeed, biometals have been shown to induce a dopaminergic neuronal loss in the substantia nigra. Although the etiology of PD is still unknown, oxidative stress dysregulation, mitochondrial dysfunction, and inhibition of both the ubiquitin-proteasome system (UPS) and autophagy are related to dopaminergic neuronal death. Herein, we addressed the involvement of redox-active biometals, iron, and copper, as oxidative stress and neuronal death inducers, as well as the current metal chelation-based therapy in PD.


Assuntos
Doença de Parkinson , Oligoelementos , Humanos , Doença de Parkinson/patologia , Cobre , Metais , Ferro , Estresse Oxidativo , Oxirredução , Neurônios Dopaminérgicos/patologia , Quelantes/farmacologia , Quelantes/uso terapêutico
6.
Molecules ; 28(2)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36677845

RESUMO

In recent years, the importance of "environmentally friendly manufacturing" has been increasing toward the establishment of a resource-recycling society. In organic synthesis, as well, it is becoming increasingly important to develop new synthetic strategies with resource conservation and the recycling of elemental resources in mind, rather than just only synthesis. Many studies on the construction of frameworks of functional molecules using ionic reactions and transition-metal-catalyzed reactions have been reported, but most of them have focused on the formation of carbon-carbon bonds. However, it is essential to introduce appropriate functional groups at appropriate positions in molecules in order for the molecules to express their functions, and furthermore, the highly selective preparation of multiple functional groups is considered important for the creation of new functional molecules. In this review, we focus on radical reactions with high functional group selectivity and overview the recent progress in practical methods for the simultaneous introduction of multiple functional groups and propose future synthetic strategies that emphasize the recycling of elemental resources and environmental friendliness.


Assuntos
Elementos de Transição , Elementos de Transição/química , Metais , Carbono/química , Técnicas de Química Sintética
7.
Molecules ; 28(2)2023 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-36677910

RESUMO

The important role of gasotransmitters in physiology and pathophysiology suggest employing gasotransmitters for biomedical treatment. Unfortunately, the difficulty in storage and controlled delivery of these gaseous molecules hindered the development of effective gasotransmitters-based therapies. The design of a safe, facile, and wide-scale method to delivery multiple gasotransmitters is a great challenge. Herein, we use an ultrasonic assisted preparation γ-cyclodextrin metal organic framework (γ-CD-MOF) as a broad-spectrum delivery vehicle for various gasotransmitters, such as SO2, NO, and H2S. The release rate of gasotransmitters could be tuned by modifying the γ-CD-MOF with different Pluronics. The biological relevance of the exogenous gasotransmitters produced by this method is evidenced by the DNA cleavage ability and the anti-inflammatory effects. Furthermore, the γ-CD-MOF composed of food-grade γ-CD and nontoxic metal salts shows good biocompatibility and particle size (180 nm). Therefore, γ-CD-MOF is expected to be an excellent tool for the study of co-delivery and cooperative therapy of gasotransmitters.


Assuntos
Ciclodextrinas , Gasotransmissores , Estruturas Metalorgânicas , Metais
8.
Nat Commun ; 14(1): 385, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36693843

RESUMO

The Zrt-/Irt-like protein (ZIP) family consists of ubiquitously expressed divalent metal transporters critically involved in maintaining systemic and cellular homeostasis of zinc, iron, and manganese. Here, we present a study on a prokaryotic ZIP from Bordetella bronchiseptica (BbZIP) by combining structural biology, evolutionary covariance, computational modeling, and a variety of biochemical assays to tackle the issue of the transport mechanism which has not been established for the ZIP family. The apo state structure in an inward-facing conformation revealed a disassembled transport site, altered inter-helical interactions, and importantly, a rigid body movement of a 4-transmembrane helix (TM) bundle relative to the other TMs. The computationally generated and biochemically validated outward-facing conformation model revealed a slide of the 4-TM bundle, which carries the transport site(s), by approximately 8 Å toward the extracellular side against the static TMs which mediate dimerization. These findings allow us to conclude that BbZIP is an elevator-type transporter.


Assuntos
Proteínas de Bactérias , Proteínas de Transporte de Cátions , Proteínas de Bactérias/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Metais/metabolismo , Zinco/metabolismo , Ferro/metabolismo
9.
Nat Commun ; 14(1): 368, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36690634

RESUMO

Selective two-electron (2e-) oxygen reduction reaction (ORR) offers great opportunities for hydrogen peroxide (H2O2) electrosynthesis and its widespread employment depends on identifying cost-effective catalysts with high activity and selectivity. Main-group metal and nitrogen coordinated carbons (M-N-Cs) are promising but remain largely underexplored due to the low metal-atom density and the lack of understanding in the structure-property correlation. Here, we report using a nanoarchitectured Sb2S3 template to synthesize high-density (10.32 wt%) antimony (Sb) single atoms on nitrogen- and sulfur-codoped carbon nanofibers (Sb-NSCF), which exhibits both high selectivity (97.2%) and mass activity (114.9 A g-1 at 0.65 V) toward the 2e- ORR in alkaline electrolyte. Further, when evaluated with a practical flow cell, Sb-NSCF shows a high production rate of 7.46 mol gcatalyst-1 h-1 with negligible loss in activity and selectivity in a 75-h continuous electrolysis. Density functional theory calculations demonstrate that the coordination configuration and the S dopants synergistically contribute to the enhanced 2e- ORR activity and selectivity of the Sb-N4 moieties.


Assuntos
Peróxido de Hidrogênio , Metais , Humanos , Antimônio , Carbono , Hipóxia , Nitrogênio , Enxofre
10.
Metallomics ; 15(1)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36617236

RESUMO

The misfolding and aggregation of amyloid-ß (Aß) peptides are histopathological features found in the brains of Alzheimer's disease (AD). To discover effective therapeutics for AD, numerous efforts have been made to control the aggregation of Aß species and their interactions with other pathological factors, including metal ions. Metal ions, such as Cu(II) and Zn(II), can bind to Aß peptides forming metal-bound Aß (metal-Aß) complexes and, subsequently, alter their aggregation pathways. In particular, redox-active metal ions bound to Aß species can produce reactive oxygen species leading to oxidative stress. In this review, we briefly illustrate some experimental approaches for characterizing the coordination and aggregation properties of metal-Aß complexes.


Assuntos
Doença de Alzheimer , Cobre , Humanos , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Cobre/metabolismo , Íons , Metais
11.
J Nanobiotechnology ; 21(1): 20, 2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36658649

RESUMO

The slightest change in the extra/intracellular concentration of metal ions results in amplified effects by signaling cascades that regulate both cell fate within the tumor microenvironment and immune status, which influences the network of antitumor immunity through various pathways. Based on the fact that metal ions influence the fate of cancer cells and participate in both innate and adaptive immunity, they are widely applied in antitumor therapy as immune modulators. Moreover, nanomedicine possesses the advantage of precise delivery and responsive release, which can perfectly remedy the drawbacks of metal ions, such as low target selectivity and systematic toxicity, thus providing an ideal platform for metal ion application in cancer treatment. Emerging evidence has shown that immunotherapy applied with nanometallic materials may significantly enhance therapeutic efficacy. Here, we focus on the physiopathology of metal ions in tumorigenesis and discuss several breakthroughs regarding the use of nanometallic materials in antitumor immunotherapeutics. These findings demonstrate the prominence of metal ion-based nanomedicine in cancer therapy and prophylaxis, providing many new ideas for basic immunity research and clinical application. Consequently, we provide innovative insights into the comprehensive understanding of the application of metal ions combined with nanomedicine in cancer immunotherapy in the past few years.


Assuntos
Neoplasias , Humanos , Neoplasias/tratamento farmacológico , Metais/uso terapêutico , Imunoterapia/métodos , Transdução de Sinais , Íons , Nanomedicina/métodos , Microambiente Tumoral
12.
Sci Rep ; 13(1): 1212, 2023 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-36681770

RESUMO

The replacement of metals in catalytic processes is highly demanded to improve sustainability and economic growth. Poor stability and metal leaching are the main drawbacks of metal-based catalytic reactions. This work represented the use of nitrogen and sulfur-co-doped mesoporous carbon material ((N, S)-MPC) as a metal-free catalyst for the degradation of 4-nitrophenol (4-NP) as a priority pollutant announced by the Environmental Protection Agency through the persulfate-based advanced oxidation process. A low amount of (N, S)-MPC catalyst (0.3 g/L) exhibited superior performance for the degradation of 4-NP within 3 h at room temperature and unadjusted pH. The COD removal was calculated to be 76% using (N, S)-MPC catalyst. Interestingly, the degradations kinetics of 4-NP followed the zero-order kinetics with the rate constant of 0.505 min-1. The radical quenching experiment was accomplished to investigate the activation pathway of degradation. A real sample from an oil and gas company was treated with the (N, S)-MPC catalyst, which showed excellent total decontamination of 61%. The recyclability and stability of the catalyst have been evaluated for three runs. Owing to the obvious benefits such as high efficiency, metal-free nature, and recyclability, the presented catalyst can improve pollutant removal from aqueous media and practical environmental remediation.


Assuntos
Carbono , Poluentes Ambientais , Nitrogênio , Porosidade , Metais , Enxofre , Estresse Oxidativo
13.
Dalton Trans ; 52(4): 1021-1029, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36601998

RESUMO

Low-dimensional organic-inorganic hybrid halides, as an important branch of metal halide materials, have attracted much attention due to their excellent photoelectric properties. Herein, we designed one new hybrid cadmium chloride [C5H14NO]CdCl3 based on combinations of the d10 metal cation (Cd2+) and choline chloride molecules. [C5H14NO]CdCl3 single crystals belong to the orthorhombic Pna21 space group and show a one-dimensional (1D) structure with distorted [CdCl5O]5- octahedra. The second harmonic generation (SHG) response of [C5H14NO]CdCl3 exhibits an intensity of approximately 0.4 × KDP. Moreover, the photoluminescence properties of the [C5H14NO]CdCl3 crystal are activated by doping with Sn2+ ions having stereochemically active lone pair 5s2 electrons. Under UV excitation conditions, bright greenish-yellow light emission can be observed, and the quantum efficiency (PLQY) is as high as 91.27%. The luminescence mechanism is revealed by combining the results of temperature dependent luminescence and density functional theory (DFT) calculation. This work can serve as a guide for the design and synthesis of emerging optical materials.


Assuntos
Compostos Inorgânicos , Metais , Elétrons , Colina , Luminescência
14.
Chem Commun (Camb) ; 59(8): 1042-1045, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36602269

RESUMO

Two multichromophoric FRET macrocycles M1 [1+1] and M2 [2+2] with red emission (λem ∼ 721 nm) composed of perylenediimide (PDI) as the energy donor and aza-BODIPY (ABDP) as the energy acceptor were synthesized by click reaction in a metal-free fashion. M1 and M2 exhibited distinct reversible ratiometric temperature responsive emission with temperature sensitivities of 0.09-0.14% °C-1 and owing to the redox active chromophores, they showed solution phase redox responsive reversible colour changes.


Assuntos
Transferência Ressonante de Energia de Fluorescência , Imidas , Metais
15.
Chem Commun (Camb) ; 59(8): 1066-1069, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36606800

RESUMO

A Li6PS5Cl-rich composite is prepared using a PEG-borate ester solid-state polymer electrolyte (BSPE). BSPE is a highly accessible compound with high ionic conductivity and excellent electrochemical stability against Li metal. Thereby, the stability of the Li6PS5Cl-rich composite with BSPE improved significantly.


Assuntos
Boratos , Eletrólitos , Íons , Lítio , Metais , Ésteres , Polímeros
16.
Inorg Chem ; 62(3): 1226-1233, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36622297

RESUMO

Inspired by the unique catalytic properties of enzymes, numerous biomimetic catalysts have been developed with the intention to realize activation of unreactive reactants under mild conditions; however, the requirement of harsh activation conditions heavily deters their practical applications. We report herein a porous metal silicate (PMS) material PMS-12 that consists of redox-active copper and vanadium metal sites, which exhibits similar catalytic behaviors of enzymes by synergistically activating different reactant molecules and generating local redox potential to facilitate electron and charge transfer, demonstrating the highest catalytic efficiency for aerobic oxidation of phenols to produce highly value-added benzoquinones under mild conditions. Therefore, this work paves a practically applicable strategy for developing high-performance heterogeneous catalysts, which could activate unreactive reactant molecules to produce highly value-added chemicals under mild conditions.


Assuntos
Metais , Fenóis , Fenóis/química , Porosidade , Oxirredução , Cobre/química
17.
Inorg Chem ; 62(3): 1210-1217, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36626658

RESUMO

Metal-organic frameworks (MOFs) have attracted significant attention over the past 2 decades due to their wide applicability as functional materials. However, targeted synthesis of novel MOFs remains problematic as their formation mechanisms are poorly understood, which forces us to rely on serendipity in the synthesis of novel MOFs. Here, we demonstrate a workflow employing the artificial force induced reaction (AFIR) method to investigate the self-assembly process of the node of the SIFSIX-3-Zn MOF, [Zn(pyz)4(SiF6)2]2- (pyz = pyrazine), in an automated manner. The workflow encompassing AFIR calculations, generation of extensive reaction path networks, propagation simulations of intermediates, and further refinements of identified formation pathways showed that the nodal structure can form through multiple competing pathways involving interconvertible intermediates. This finding provides a plausible rationale for the stochastic multistage processes believed to be key in MOF formation. Furthermore, this work represents the first application of an automated reaction mechanism discovery method to a MOF system using a general workflow that is applicable to study the formation of other MOF motifs as well.


Assuntos
Estruturas Metalorgânicas , Metais , Pirazinas , Zinco
18.
Biomed Phys Eng Express ; 9(2)2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36645907

RESUMO

We propose a technique for metal artefact reduction in digital tomosynthesis reconstruction. Although the problem was addressed earlier in the literature, we suggest another approach, which is, in our opinion, simpler, and easier to implement. It is a two-stage algorithm. At the first stage, attenuation images are segmented by decomposing their intensity distributions into gaussian-like components. Statistical information contained in each component is used for pixel classification. Components corresponding to metallic objects are identified, and a pixel threshold value separating regions occupied by metal objects from the rest of the image is found. Based on this value, at the second stage, a smooth mapping of image intensity is applied. This makes dense regions transparent, resulting in the artefact reduction in reconstruction. The methodology is demonstrated by several examples.


Assuntos
Artefatos , Tomografia Computadorizada por Raios X , Tomografia Computadorizada por Raios X/métodos , Radiografia , Algoritmos , Metais
19.
Artigo em Inglês | MEDLINE | ID: mdl-36674083

RESUMO

Wildfires constitute a source of contamination to both freshwater and marine ecosystems. This study aimed to compare the antioxidant defense response of the freshwater clam Corbicula fluminea and the marine cockle (Cerastoderma edule) to wildfire ash exposure and the concomitant metal body burden. Organisms were exposed to different concentrations (0%, 12.5%, 25%, 50%, and 100%) of aqueous extracts of Eucalypt ash (AEAs) from a moderate-to-high severity wildfire. The activity of various enzymes, as well as lipid peroxidation, protein content, and metal body burden, were determined after 96 h of exposure. A significant increase in the protein content of soft tissues was observed for C. edule at AEA concentrations ≥ 25%, unlike for C. fluminea. Similarly, significant effects on lipid peroxidation were observed for cockles, but not for clams. For both species, a significant effect in the total glutathione peroxidase activity was observed at AEA concentrations ≥ 25%. Relative to the control, AEAs-exposed clams showed higher Cd content, whereas AEAs-exposed cockles showed higher Cu content, thus exhibiting different responses to the exposure to wildfire ash. The susceptibility of bivalves to ashes, at environmentally relevant concentrations, raises concern about the effects of post-fire runoff to bivalve species.


Assuntos
Corbicula , Poluentes Químicos da Água , Incêndios Florestais , Animais , Antioxidantes/metabolismo , Ecossistema , Carga Corporal (Radioterapia) , Metais/toxicidade , Metais/metabolismo , Corbicula/metabolismo , Proteínas , Água Doce , Poluentes Químicos da Água/análise
20.
Int J Mol Sci ; 24(2)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36674728

RESUMO

DNAzyme is a class of DNA molecules that can perform catalytic functions with high selectivity towards specific metal ions. Due to its potential applications for biosensors and medical therapeutics, DNAzyme has been extensively studied to characterize the relationships between its biochemical properties and functions. Similar to protein enzymes and ribozymes, DNAzymes have been found to undergo conformational changes in a metal-ion-dependent manner for catalysis. Despite the important role the conformation plays in the catalysis process, such structural and dynamic information might not be revealed by conventional approaches. Here, by using the single-molecule fluorescence resonance energy transfer (smFRET) technique, we were able to investigate the detailed conformational dynamics of a uranyl-specific DNAzyme 39E. We observed conformation switches of 39E to a folded state with the addition of Mg2+ and to an extended state with the addition of UO22+. Furthermore, 39E can switch to a more compact configuration with or without divalent metal ions. Our findings reveal that 39E can undergo conformational changes spontaneously between different configurations.


Assuntos
DNA Catalítico , DNA Catalítico/metabolismo , Metais/química , Transferência Ressonante de Energia de Fluorescência , Conformação de Ácido Nucleico , Íons/química
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