Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 747
Filtrar
1.
Plant Physiol Biochem ; 208: 108519, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38490154

RESUMO

Rare earth elements (REE) have been extensively used in a variety of applications such as cell phones, electric vehicles, and lasers. REEs are also used as nanomaterials (NMs), which have distinctive features that make them suitable candidates for biomedical applications. In this review, we have highlighted the role of rare earth element nanomaterials (REE-NMs) in the growth of plants and physiology, including seed sprouting rate, shoot biomass, root biomass, and photosynthetic parameters. In addition, we discuss the role of REE-NMs in the biochemical and molecular responses of plants. Crucially, REE-NMs influence the primary metabolites of plants, namely sugars, amino acids, lipids, vitamins, enzymes, polyols, sorbitol, and mannitol, and secondary metabolites, like terpenoids, alkaloids, phenolics, and sulfur-containing compounds. Despite their protective effects, elevated concentrations of NMs are reported to induce toxicity and affect plant growth when compared with lower concentrations, and they not only induce toxicity in plants but also affect soil microbes, aquatic organisms, and humans via the food chain. Overall, we are still at an early stage of understanding the role of REE in plant physiology and growth, and it is essential to examine the interaction of nanoparticles with plant metabolites and their impact on the expression of plant genes and signaling networks.


Assuntos
Metais Terras Raras , Nanoestruturas , Resiliência Psicológica , Humanos , Metais Terras Raras/análise , Metais Terras Raras/química , Metais Terras Raras/metabolismo , Plantas/metabolismo , Desenvolvimento Vegetal , Solo/química
2.
ACS Appl Mater Interfaces ; 16(13): 16912-16926, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38527460

RESUMO

Bioinspired strategies have been given extensive attention for the recovery of rare earth elements (REEs) from waste streams because of their high selectivity, regeneration potential, and sustainability as well as low cost. Lanmodulin protein is an emerging biotechnology that is highly selective for REE binding. Mimicking lanmodulin with shorter peptides is advantageous because they are simpler and potentially easier to manipulate and optimize. Lanmodulin-derived peptides have been found to bind REEs, but their properties have not been explored when immobilized on solid substrates, which is required for many advanced separation technologies. Here, two peptides, LanM1 and scrambled LanM1, are designed from the EF-hand loop 1 of lanmodulin and investigated for their binding affinity toward different REEs when surface-bound. First, the ability of LanM1 to bind REEs was confirmed and characterized in solution using circular dichroism (CD), nuclear magnetic resonance (NMR), and molecular dynamics (MD) simulations for Ce(III) ions. Isothermal titration calorimetry (ITC) was used to further analyze the binding of the LanM1 to Ce(III), Nd(III), Eu(III), and Y(III) ions and in low-pH conditions. The performance of the immobilized peptides on a model gold surface was examined using a quartz crystal microbalance with dissipation (QCM-D). The studies show that the LanM1 peptide has a stronger REE binding affinity than that of scrambled LanM1 when in solution and when immobilized on a gold surface. QCM-D data were fit to the Langmuir adsorption model to estimate the surface-bound dissociation constant (Kd) of LanM1 with Ce(III) and Nd(III). The results indicate that LanM1 peptides maintain a high affinity for REEs when immobilized, and surface-bound LanM1 has no affinity for potential competitor calcium and copper ions. The utility of surface-bound LanM1 peptides was further demonstrated by immobilizing them to gold nanoparticles (GNPs) and capturing REEs from solution in experiments utilizing an Arsenazo III-based colorimetric dye displacement assay and ultraviolet-visible (UV-vis) spectrophotometry. The saturated adsorption capacity of GNPs was estimated to be around 3.5 µmol REE/g for Ce(III), Nd(III), Eu(III), and Y(III) ions, with no binding of non-REE Ca(II) ions observed.


Assuntos
Nanopartículas Metálicas , Metais Terras Raras , Ouro , Metais Terras Raras/química , Peptídeos , Íons
3.
J Mater Chem B ; 12(8): 1947-1972, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38299679

RESUMO

Second near-infrared (NIR-II) fluorescence imaging (FLI) has gained widespread interest in the biomedical field because of its advantages of high sensitivity and high penetration depth. In particular, rare earth-doped nanoprobes (RENPs) have shown completely different physical and chemical properties from macroscopic substances owing to their unique size and structure. This paper reviews the synthesis methods and types of RENPs for NIR-II imaging, focusing on new methods to enhance the luminous intensity of RENPs and multi-band imaging and multi-mode imaging of RENPs in biological applications. This review also presents an overview of the challenges and future development prospects based on RENPs in NIR-II regional bioimaging.


Assuntos
Metais Terras Raras , Metais Terras Raras/química , Imagem Óptica/métodos , Corantes Fluorescentes/química
4.
Water Res ; 252: 121184, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38377699

RESUMO

Singlet oxygen (1O2) is extensively employed in the fields of chemical, biomedical and environmental. However, it is still a challenge to produce high- concentration 1O2 by dioxygen activation. Herein, a system of carbon-supported rare-earth oxide nanocluster and single atom catalysts (named as RE2O3/RE-C, RE=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y) with similar morphology, structure, and physicochemical characteristic are constructed to activate dissolved oxygen (DO) to enhance 1O2 production. The catalytic activity trends and mechanisms are revealed experimentally and are also proven by theoretical analyses and calculations. The 1O2 generation activity trend is Gd2O3/Gd-C>Er2O3/Er-C>Sm2O3/Sm-C>pristine carbon (C). More than 95.0% of common antibiotics (ciprofloxacin, ofloxacin, norfloxacin and carbamazepine) can be removed in 60 min by Gd2O3/Gd-C. Density functional theory calculations indicate that Gd2O3 nanoclusters and Gd single atoms exhibit the moderate adsorption energy of ·O2- to enhance 1O2 production. This study offers a universal strategy to enhance 1O2 production in dioxygen activation for future application and reveals the natural essence of basic mechanisms of 1O2 production via rare-earth oxide nanoclusters and rare-earth single atoms.


Assuntos
Metais Terras Raras , Oxigênio Singlete , Óxidos/química , Oxigênio , Antibacterianos , Metais Terras Raras/análise , Metais Terras Raras/química
5.
Dalton Trans ; 53(9): 4204-4213, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38323916

RESUMO

Marbofloxacin (MB) is a newly developed fluoroquinolone antibiotic used especially as a veterinary drug. It may be regarded as the improved version of enrofloxacin owing to its antibacterial activity, enhanced bioavailability, and pharmacokinetic-pharmacodynamic (PK-PD) properties. In this study, nine heavy rare-earth ions (Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) were selected in light of their potential antibacterial activity and satisfactory biosafety to afford the corresponding rare-earth metal complexes of MB: the MB-Ln series. Their chemical structures and coordination patterns were characterized using IR spectroscopy, HRMS, TGA, and X-ray single-crystal diffraction analysis. Our results confirmed that all the MB-Ln complexes yielded the coincident coordination modes with four MB ligands coordinating to the Ln(III) center. In vitro antibacterial screening on five typical bacteria strains revealed that the MB-Ln complexes exhibited antibacterial activities comparable with MB, as indicated by the MIC/MBC values, in which Escherichia coli and Salmonella typhi were the most sensitive ones to MB-Ln. Furthermore, the MB-Ln complexes were found to be much less toxic in vivo than MB, as suggested by the evaluated LD50 (50% lethal dose) values. All the MB-Ln series complexes fell in the LD50 range of 5000-15 000 mg kg-1, while the LD50 value of MB was only 1294 mg kg-1. Furthermore, MB-Lu, as the selected representative of MB-Ln, could effectively inhibit the activity of DNA gyrase, the same as MB, suggesting the primary antibacterial mechanism of the MB-Ln series. The results demonstrated the good prospects and potential of metal-based veterinary drugs with better drug performance.


Assuntos
Metais Terras Raras , Drogas Veterinárias , Estrutura Molecular , Metais Terras Raras/farmacologia , Metais Terras Raras/química , Fluoroquinolonas/farmacologia , Antibacterianos/farmacologia , Íons/química
6.
ACS Biomater Sci Eng ; 10(2): 1128-1138, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38221709

RESUMO

The physiological state of the human body can be indicated by analyzing the composition of sweat. In this research, a fluorescence-recovered wearable hydrogel patch has been designed and realized which can noninvasively monitor the glucose concentration in human sweat. Rare-earth nanoparticles (RENPs) of NaGdF4 doped with different elements (Yb, Er, and Ce) are synthesized and optimized for better luminescence in the near-infrared second (NIR-II) and visible region. In addition, RENPs are coated with CoOOH of which the absorbance has an extensive peak in the visible and NIR regions. The concentration of H2O2 in the environment can be detected by the fluorescence recovery degree of CoOOH-modified RENPs based on the fluorescence resonance energy transfer effect. For in vivo detection, the physiological state of oxidative stress at tumor sites can be visualized through its fluorescence in NIR-II with low background noise and high penetration depth. For the in vitro detection, CoOOH-modified RENP and glucose oxidase (GOx) were doped into a polyacrylamide hydrogel, and a patch that can emit green upconversion fluorescence under a 980 nm laser was prepared. Compared with the conventional electrochemical detection method, the fluorescence we presented has higher sensitivity and linear detection region to detect the glucose. This improved anti-interference sweat patch that can work in the dark environment was obtained, and the physiological state of the human body is conveniently monitored, which provides a new facile and convenient method to monitor the sweat status.


Assuntos
Cobalto , Metais Terras Raras , Nanopartículas , Óxidos , Dispositivos Eletrônicos Vestíveis , Humanos , Fluorescência , Glucose , Hidrogéis , Peróxido de Hidrogênio , Metais Terras Raras/química , Nanopartículas/química
7.
Luminescence ; 39(1): e4612, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37927204

RESUMO

Red and green rare-earth ion (RE3+ ) (RE = Eu, Tb):MgLa2 V2 O9 micro-powder phosphors were produced utilizing a standard solid-state chemical process. The X-ray diffraction examination performed on the phosphors showed that they were crystalline and had a monoclinic structure. The particles grouped together, as shown in the scanning electron microscopy (SEM) images. Powder phosphors were examined using a variety of spectroscopic techniques, including photoluminescence (PL), Fourier-transform infrared, and energy dispersive X-ray spectroscopy. Brilliant red emission at 615 nm (5 D0  â†’ 7 F2 ) having an excitation wavelength (λexci ) of 396 nm (7 F0  â†’ 5 L6 ) and green emission at 545 nm (5 D4  â†’ 7 F5 ) having an λexci  = 316 nm (5 D4  â†’ 7 F2 ) have both been seen in the emission spectra of Tb3+ :MgLa2 V2 O9 nano-phosphors. The emission mechanism that is raised in Eu3+ :MgLa2 V2 O9 and Tb3+ :MgLa2 V2 O9 powder phosphors has been explained in an energy level diagram.


Assuntos
Substâncias Luminescentes , Metais Terras Raras , Substâncias Luminescentes/química , Pós , Metais Terras Raras/química , Microscopia Eletrônica de Varredura , Espectrometria por Raios X
8.
Luminescence ; 39(1): e4591, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37675627

RESUMO

Cerium has been widely used as a dopant in luminescent materials due to its unique electronic configurations. It is generally anticipated that the luminescence properties of rare-earth-doped materials are closely related to the local environment of activators, especially for Ce3+ . In addition, it is convenient to modulate its emission wavelength by adjusting the composition and structure. In this study, we systematically analyzed the microstructure of the Ce-doped CaYAlO4 system at atomic resolution. The quantitive results indicated that the structure distortion greatly influenced the valence state of the Ce dopant, which is critical to its luminescence efficiency. In addition, valence variations also exist from surface to inner structure due to the big distortion area around the surface. Our results unravel the interplay of local structure and valence transitions in Ce-doped aluminate phosphors, which has the potential to be applied in other luminescent materials.


Assuntos
Cério , Substâncias Luminescentes , Metais Terras Raras , Luminescência , Substâncias Luminescentes/química , Metais Terras Raras/química , Cério/química
9.
Bioorg Chem ; 143: 107040, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38141331

RESUMO

Rare earth elements (REEs) are a group of critical minerals and extensively employed in new material manufacturing. However, separation of lanthanides is difficult because of their similar chemical natures. Current lanthanide leaching and separation methods require hazardous compounds, resulting in severe environmental concerns. Bioprocessing of lanthanides offers an emerging class of tools for REE separation due to mild leaching conditions and highly selective separation scenarios. In the course of biopreparation, engineered microbes not only dissolve REEs from ores but also allow for selective separation of the lanthanides. In this review, we present an overview of recent advances in microbes and proteins used for the biomanufacturing of lanthanides and discuss high value-added applications of REE-derived biomaterials. We begin by introducing the fundamental interactions between natural microbes and REEs. Then we discuss the rational design of chassis microbes for bioleaching and biosorption. We also highlight the investigations on REE binding proteins and their applications in the synthesis of high value-added biomaterials. Finally, future opportunities and challenges for the development of next generation lanthanide-binding biological systems are discussed.


Assuntos
Elementos da Série dos Lantanídeos , Metais Terras Raras , Metais Terras Raras/química
10.
Nano Lett ; 23(23): 11203-11210, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38088357

RESUMO

Intravital luminescence imaging in the second near-infrared window (NIR-II) enables noninvasive deep-tissue imaging with high spatiotemporal resolution of live mammals because of the properties of suppressed light scattering and diminished autofluorescence in the long-wavelength region. Herein, we present the synthesis of a downconversion luminescence rare-earth nanocrystal with a core-shell-shell structure (NaYF4@NaYbF4:Er,Ce@NaYF4:Ca). The structure efficiently maximized the doping concentration of the sensitizers and increased Er3+ luminescence while preventing cross relaxation. Furthermore, Ce3+ doping in the middle layer efficiently limited the upconversion pathway and increased downconversion by 24-fold to produce bright 1550 nm luminescence under 975 nm excitation. Finally, optimizing the inert shell coating of NaYF4:Ca and liposome encapsulation reduced the luminescence quenching impact by water and improved biological metabolism. Thus, our synthesized biocompatible, ultrabright NIR-II probes provide high contrast and resolution for through-scalp and through-skull luminescence imaging of mice cerebral vasculature without craniotomy as well as imaging of mouse hindlimb microvessels.


Assuntos
Metais Terras Raras , Nanopartículas , Camundongos , Animais , Metais Terras Raras/química , Diagnóstico por Imagem/métodos , Nanopartículas/química , Luminescência , Mamíferos
11.
Int J Mol Sci ; 24(23)2023 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-38069403

RESUMO

A specialized empirical (Spec-zd Emp) system of ionic radii (SIR) for R = Y3+, La3+, Ln3+, and F1- (R rare earth elements (REE)) was derived from the dependence of lanthanide contraction (LC) on the atomic number (Z) of lanthanides (Ln). LC decreased the radius of the cation with increasing Z. The structures of t-RF3 (LaF3-NdF3, "pseudot-SmF3") of the LaF3 type, 11 ß-LnF3 (Ln = Sm-Lu), and ß-YF3 of the ß-YF3 type were studied. The empirical basis of the shortest (F-F)min and (R-F)min distances was calculated from the structural data for the RF3 complete series. The dependence of (F-F)min on Z reached saturation at Z = 67 (Ho). The base F1- radius r- = 1.2539(16) Å was calculated as the arithmetic mean of five (F-F)min in LnF3 with Ln = Ho-Lu. For the LnF3 series with Ln contributions up to 75 % wt., the dependence of (Ln-F)min on Z reflected the non-uniformity of the 4f orbital filling. SIR was calculated as the difference in the empirical constants of RF3 (ionic radii of (R,Ln)3+ (r+) and F1- (r-)), the change in which was continuous over the series and did not depend on the type of structure: r+ = (ZR-F)min - ½(F-F)min (Z = 57-71). The changes in LC in the LnF3 series were described by a third-degree polynomial. LC reduced r+ by 24% (percentage relative to less) from 1.1671(16) Å (La3+) to 0.9439(17) Å (Lu3+). In the Spec-zd Emp SIR, r+ were constants that did not require corrections for a coordination number (CN). A comparison of r+ in the Spec-zd Emp SIR with other SIRs was performed.


Assuntos
Elementos da Série dos Lantanídeos , Metais Terras Raras , Elementos da Série dos Lantanídeos/química , Rádio (Anatomia) , Metais Terras Raras/química , Íons
12.
Angew Chem Int Ed Engl ; 62(50): e202312665, 2023 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-37903741

RESUMO

Aberrant expressions of biomolecules occur much earlier than tumor visualized size and morphology change, but their common measurement strategies such as biopsy suffer from invasive sampling process. In vivo imaging of slight biomolecule expression difference is urgently needed for early cancer detection. Fluorescence of rare earth nanoparticles (RENPs) in second near-infrared (NIR-II) region makes them appropriate tool for in vivo imaging. However, the incapacity to couple with signal amplification strategies, especially programmable signal amplification strategies, limited their application in lowly expressed biomarkers imaging. Here we develop a 980/808 nm NIR programmed in vivo microRNAs (miRNAs) magnifier by conjugating activatable DNAzyme walker set to RENPs, which achieves more effective NIR-II imaging of early stage tumor than size monitoring imaging technique. Dye FD1080 (FD1080) modified substrate DNA quenches NIR-II downconversion emission of RENPs under 808 nm excitation. The miRNA recognition region in DNAzyme walker is sealed by a photo-cleavable strand to avoid "false positive" signal in systemic circulation. Upconversion emission of RENPs under 980 nm irradiation activates DNAzyme walker for miRNA recognition and amplifies NIR-II fluorescence recovery of RENPs via DNAzyme catalytic reaction to achieve in vivo miRNA imaging. This strategy demonstrates good application potential in the field of early cancer detection.


Assuntos
DNA Catalítico , Metais Terras Raras , MicroRNAs , Neoplasias , Humanos , Metais Terras Raras/química , Neoplasias/diagnóstico por imagem , Neoplasias/patologia , Espectroscopia de Luz Próxima ao Infravermelho/métodos
13.
Luminescence ; 38(12): 2034-2047, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37675584

RESUMO

In this article, photoluminescence (PL) and thermoluminescence (TL) properties of ZrO2 , ZrO2 :Dy3+ , ZrO2 :Dy3+ -Gd3+ , ZrO2 :Dy3+ -Yb3+ , ZrO2 :Dy3+ -Er3+ , and ZrO2 :Dy3+ -Sm3+ phosphors synthesized by the Pechini method were investigated. The crystal structure, thermal properties, morphology, PL and TL properties were investigated using X-ray powder diffraction (XRD), differential thermal analysis/thermogravimetric analysis (DTA/TGA), scanning electron microscopy (SEM), PL and TL, respectively. The room temperature emission bands corresponding to 4 F9/2  â†’ 6 HJ (J = 9/2, 11/2, 13/2 and 15/2) transitions of Dy3+ ions were measured. The phosphors were analysed using Tm -TSTOP , variable dose, and computerized glow curve fitting methods. Reusability, dose-response, and fading characteristics were investigated. The phosphors have a natural TL emission that vanished by heating treatment. Moreover, new peaks with similar properties to the natural emissions were observed after high-dose irradiation and long-term fading experiments. The glow curves of the phosphors have 13 individual peaks and many low- and high-temperature satellite peaks. The origin of the peaks is ZrO2 host material and doping with rare-earth ions (Gd3+ , Dy3+ , Yb3+ , Er3+ and Sm3+ ) does not lead to a new glow peak. The dopants cause drastic changes in individual peak intensities of ZrO2 .The initial fading rates of all the phosphors are relatively fast, but they slow down as time goes on.


Assuntos
Luminescência , Metais Terras Raras , Metais Terras Raras/química , Difração de Raios X , Microscopia Eletrônica de Varredura , Íons
14.
Luminescence ; 38(10): 1825-1835, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37539834

RESUMO

For the manufacture of hollow nanospheres that had different shapes, three distinct templates-urea, carbon microspheres, and polyethylene glycol 20,000-were used. The relationship between microspheres with various hollow structures and their luminescent properties were investigated. Furthermore, the effects of annealing temperature and the proportion of rare earth Eu3+ /Tb3+ ions in the reaction were investigated using the structural characteristics of the microspheres and fluorescent materials. The fluorescent materials were wrapped on the outer surface of the microspheres. The ideal balance between the best structure and superior luminescent performance was found, to create reasonably good white light.


Assuntos
Metais Terras Raras , Nanocompostos , Luminescência , Dióxido de Silício/química , Microesferas , Metais Terras Raras/química
15.
Compr Rev Food Sci Food Saf ; 22(5): 3732-3764, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37548602

RESUMO

The misuse of chemicals in agricultural systems and food production leads to an increase in contaminants in food, which ultimately has adverse effects on human health. This situation has prompted a demand for sophisticated detection technologies with rapid and sensitive features, as concerns over food safety and quality have grown around the globe. The rare earth ion-doped upconversion nanoparticle (UCNP)-based sensor has emerged as an innovative and promising approach for detecting and analyzing food contaminants due to its superior photophysical properties, including low autofluorescence background, deep penetration of light, low toxicity, and minimal photodamage to the biological samples. The aim of this review was to discuss an outline of the applications of UCNPs to detect contaminants in food matrices, with particular attention on the determination of heavy metals, pesticides, pathogenic bacteria, mycotoxins, and antibiotics. The review briefly discusses the mechanism of upconversion (UC) luminescence, the synthesis, modification, functionality of UCNPs, as well as the detection principles for the design of UC biosensors. Furthermore, because current UCNP research on food safety detection is still at an early stage, this review identifies several bottlenecks that must be overcome in UCNPs and discusses the future prospects for its application in the field of food analysis.


Assuntos
Metais Terras Raras , Nanopartículas , Humanos , Análise de Perigos e Pontos Críticos de Controle , Metais Terras Raras/química , Nanopartículas/química , Inocuidade dos Alimentos , Luminescência
16.
Nanoscale ; 15(23): 10141-10148, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37265388

RESUMO

Polarized luminescence has many applications in energy saving, displays, communication and other fields. Here, electrically tunable polarized luminescence of aligned Eu(tta)3phen/E7 composites is successfully obtained based on the interaction between liquid crystal (LC) hosts and rare earth (RE) complex guests. The generation mechanism of the polarization effect is thoroughly explored from three different aspects. The polarized luminescence of Eu(tta)3phen/E7 composites is closely related to the polarized energy absorption of incident light, the site symmetry of Eu3+ ions for oriented Eu(tta)3phen complex molecules, and the polarized energy transfer from E7 to Eu(tta)3phen. The convenient control of the well-aligned Eu(tta)3phen complex by simply embedding the Eu(III) complex guest in the E7 host and utilizing small-magnitude electric field forces is explicitly confirmed. The E7 host not only provides the orientation condition for the electrically tunable polarized luminescence but also promotes the degree of polarization through polarized energy transfer. The polarized spectral properties and the symmetry of the Eu3+ site of the aligned Eu(tta)3phen complexes are described in detail. The analysis of the generation mechanism of polarized luminescence supplements the research content in the field of RE/LC composites and paves the way for exciting novel advances in the field of polarized emission.


Assuntos
Cristais Líquidos , Metais Terras Raras , Luminescência , Metais Terras Raras/química , Eletricidade , Transferência de Energia
17.
Org Lett ; 25(24): 4468-4472, 2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37294030

RESUMO

Rare earth metals exhibit high catalytic activity and selectivity in various organic reactions due to their unique electronic properties. Among them, praseodymium has shown high catalytic activity under mild reaction conditions compared with transitional metals. Here, we report a strategy of Pr-catalyzed aerobic dehydrogenative aromatization of saturated N-heterocycles to produce 7 classes of products with a broad substrate scope.


Assuntos
Metais Terras Raras , Elementos de Transição , Metais Terras Raras/química , Catálise
18.
Front Public Health ; 11: 1058013, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37181707

RESUMO

Objective: The current research aimed to examine how dietary intake and rare earth elements may affect the development of tongue cancer. Methods: The serum levels of 10 rare earth elements (REEs) in 171 cases and 171 healthy matched controls were measured by inductively coupled plasma mass spectrometry (ICP-MS). The conditional logistic regression was used to examine the relationship between dietary intake, serum levels of 10 REEs, and tongue cancer. Mediation effect and multiplicative interaction analysis were then performed to estimate the potential contribution of REEs in dietary intake associated with tongue cancer. Results: Compared with the control group, patients with tongue cancer consumed significantly less fish, seafood, fruit, green leafy vegetables, and non-green leafy vegetables, with higher serum praseodymium (Pr), dysprosium (Dy), and lanthanum (La) levels, and lower serum cerium (Ce) and scandium (Sc) levels. The interaction effect was observed between some REEs and food categories. Green vegetables' impact on the risk of tongue cancer is partially attributed to the La and Thorium (Th) elements (P < 0.05, the mediated proportion were 14.933% and 25.280%, respectively). The effect of non-green leafy vegetables for tongue cancer mediated via Pr, Dy, and Th (P < 0.05, the mediated proportion were 0.408%, 12.010%, and 8.969%, respectively), and the Sc components in seafood (P < 0.05, the mediated proportion was 26.120%) is partly responsible for their influence on the risk of tongue cancer. Conclusion: The correlation between REEs and dietary intakes for tongue cancer is compact but intricate. Some REEs interact with food intake to influence tongue cancer, while others act as a mediator.


Assuntos
Metais Terras Raras , Neoplasias da Língua , Animais , Análise de Mediação , Metais Terras Raras/análise , Metais Terras Raras/química , China , Ingestão de Alimentos
19.
Adv Mater ; 35(33): e2303457, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37243571

RESUMO

Rare earth materials play an irreplaceable role in biomedical and high technology fields. However, typical mining and extraction approaches to rare earth elements (REEs) often lead to severe environmental problems and resource wastage due to the involvement of hazardous chemicals. Although biomining shows elegant alternatives, there are still grand challenges to sustainably isolate and recover REEs in nature because of insufficient metal-extracting microbes and RE-scavenging macromolecular tools. To obtain high-performance rare earth materials directly from rare earth ore, a new generation of biological synthesis strategies needs to be developed for the efficient preparation of REEs. The microbial synthesis system established here has achieved active biomanufacturing of high-purity rare earth products. Further, through employing robust affinity columns bioconjugated with structurally engineered proteins, outstanding separation of Eu/Lu and Dy/La is acquired with the purity of 99.9% (Eu), 97.1% (La), and 92.7% (Dy). More importantly, in situ one-pot synthesis of lanthanide-dependent methanol dehydrogenase is well harnessed and exclusively adsorbs La, Ce, Pr, and Nd in RE tailing for advanced biocatalysis, indicating high value-added application. Therefore, this novel biosynthetic platform provides an insightful roadmap to expand the scope of chassis engineering in terms of biofoundry and to manufacture valuable bioproducts related to REEs.


Assuntos
Elementos da Série dos Lantanídeos , Metais Terras Raras , Metais Terras Raras/análise , Metais Terras Raras/química , Substâncias Perigosas , Mineração
20.
J Hazard Mater ; 451: 131221, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-36934702

RESUMO

Ion-adsorption rare earth mining results in the production of high levels of nitrogen, multiple metals, and strong acidic mine drainage (AMD), the impacts of which on microbial assembly and ecological functions remain unclear. To address this knowledge gap, we collected river sediments from the watershed of China's largest ion-adsorption rare earth mine and analyzed the bacterial community's structure, function, and assembly mechanisms. Results showed that bacterial community assembly was weakly affected by spatial dispersion, and dispersal limitation and homogeneous selection were the dominant ecological processes, with the latter increasing with pollution gradients. Bacterial alpha diversity decreased with pollution, which was mainly influenced by lead (Pb), pH, rare earth elements (REEs), and electrical conductivity (EC). However, bacteria developed survival strategies (i.e., enhanced acid tolerance and interspecific competition) to adapt to extreme environments, sustaining species diversity and community stability. Community structure and function showed a consistent response to the polluted environment (r = 0.662, P = 0.001). Enhanced environmental selection reshaped key microbial-mediated biogeochemical processes in the mining area, in particular weakening the potential for microbial denitrification. These findings provide new insights into the ecological response of microbes to compound pollution and offer theoretical support for proposing effective remediation and management strategies for polluted areas.


Assuntos
Metais Terras Raras , Mineração , Adsorção , Metais Terras Raras/química , Bactérias , China
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...