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1.
Clin Oral Investig ; 28(6): 338, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38797781

RESUMEN

OBJECTIVES: To clinically compare the effects of broader archwires to standard archwires, using conventional brackets in both cases, on the transverse and incisor changes in maxillary and mandibular arches during leveling and alignment. MATERIALS AND METHODS: Fifty-two patients presenting with crowding were allocated into two groups; one group received the broad Damon archwires while the other received standard 3M OrthoForm III Ovoid archwires. All participants were treated with conventional brackets using similar archwire sequences (0.014, 0.018, 0.016 × 0.022/0.016 × 0.025, 0.019 × 0.025 NiTi/CuNiTi archwires). Digital casts were obtained from alginate impressions before treatment (T0) and six weeks after inserting 0.019 × 0.025 NiTi archwires (T1). Pretreatment (T0) and post-alignment (T1) lateral cephalograms were obtained for each patient. The primary outcomes were the changes in the transverse arch dimensions and incisor inclination. The secondary outcomes were the horizontal and vertical linear changes in incisor position. RESULTS: Complete data were collected for 47 patients. There was a significant increase in arch width during treatment within each group, except for upper inter-molar width in 3M group (P = 0.071). Damon wire induced a statistically significant increase in maxillary inter-second premolar width (P = 0.042), and mandibular inter-first premolar (P = 0.043), inter-second premolar (P = 0.008) and inter-molar widths (P = 0.033) compared to 3M group. The increase in incisor proclination and the linear change in incisor position were significant within each group, with less mandibular incisor proclination (P = 0.004) and horizontal advancement (P = 0.038) in the Damon group. CONCLUSIONS: Damon archwires created a comparatively greater increase in the maxillary inter-second premolar width and the mandibular inter-first premolar, inter-second premolar, and inter-molar widths, and less proclination and horizontal advancement in mandibular incisors. The study provides invaluable evidence that using broad archwires with self-ligating brackets is the reason behind any greater expansion observed in this system rather than the unique mechanical and biological features exerted by the self-ligating system. CLINICAL RELEVANCE: Our results suggest that Damon archwire might be a better alternative compared to the narrower standard archwires that are usually used with conventional brackets, especially in the mandibular arch, in cases where mild to moderate crowding is planned to be resolved with a non-extraction approach. However, as arch expansion in the absence of posterior crossbites raises the question of long-term stability, the reported advantage of the use of wide wires should be interpreted with caution and should be considered in the retention phase, bearing in mind that achieving a good post-treatment occlusion is important for enhancing post-treatment stability.


Asunto(s)
Cefalometría , Incisivo , Maloclusión , Diseño de Aparato Ortodóncico , Soportes Ortodóncicos , Alambres para Ortodoncia , Humanos , Femenino , Masculino , Maloclusión/terapia , Adolescente , Níquel/química , Arco Dental , Titanio/química , Resultado del Tratamiento , Técnicas de Movimiento Dental/instrumentación , Técnicas de Movimiento Dental/métodos , Cobre
2.
ACS Sens ; 9(5): 2395-2401, 2024 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-38722860

RESUMEN

PdNi alloy thin films demonstrate exceptional hydrogen sensing performance and exhibit significant potential for application in surface acoustic wave (SAW) hydrogen sensors. However, the long-term stability of SAW H2 sensors utilizing PdNi films as catalysts experiences a substantial decrease during operation. In this paper, X-ray photoelectron spectroscopy (XPS) is employed to investigate the failure mechanisms of PdNi thin films under operational conditions. The XPS analysis reveals that the formation of PdO species on PdNi thin films plays a crucial role in the failure of hydrogen sensing. Additionally, density functional theory (DFT) calculations indicate that hydrogen atoms encounter a diffusion energy barrier during the penetration process from the PdNiOx surface to the subsurface region. The identification of PdNi film failure mechanisms through XPS and DFT offers valuable insights into the development of gas sensors with enhanced long-term stability. Guided by these mechanisms, we propose a method to restore the hydrogen sensing response time and magnitude to a certain extent by reducing the partially oxidized surface of the PdNi alloy under a hydrogen atmosphere at 70 °C, thereby restoring Pd to its metallic state with zero valence.


Asunto(s)
Hidrógeno , Níquel , Oxidación-Reducción , Paladio , Sonido , Hidrógeno/química , Paladio/química , Níquel/química , Propiedades de Superficie , Teoría Funcional de la Densidad , Espectroscopía de Fotoelectrones , Aleaciones/química
3.
Bioelectrochemistry ; 158: 108728, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38733721

RESUMEN

Herein, an aptasensor based on a signal amplification strategy was developed for the sensitive detection of procymidone (PCM). AgPd nanoparticles/Polenimine Graphite oxide (AgPdNPs/PEI-GO) was weaned as electrode modification material to facilitate electron transport and increase the active sites on the electrode surface. Besides, Pt@Ni-Co nanoboxes (Pt@Ni-CoHNBs) were utilized to be carriers for signaling tags, after hollowing ZIF-67 and growing Pt, the resulting Pt@Ni-CoHNBs has a tremendous amounts of folds occurred on the surface, enables it to carry a larger quantity of thionine, thus amplify the detectable electrochemical signal. In the presence of PCM, the binding of PCM to the signal probe would trigger a change in electrical signal. The aptasensor was demonstrated with excellent sensitivity and a low detection limit of 0.98 pg·mL-1, along with a wide linear range of 1 µg·mL-1 to 1 pg·mL-1. Meanwhile, the specificity, stability and reproducibility of the constructed aptasensor were proved to be satisfactory.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Técnicas Electroquímicas , Grafito , Límite de Detección , Nanopartículas del Metal , Paladio , Platino (Metal) , Plata , Grafito/química , Aptámeros de Nucleótidos/química , Técnicas Electroquímicas/métodos , Platino (Metal)/química , Técnicas Biosensibles/métodos , Nanopartículas del Metal/química , Paladio/química , Plata/química , Níquel/química , Polietileneimina/química , Cobalto/química , Reproducibilidad de los Resultados
4.
Anal Chim Acta ; 1306: 342613, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38692794

RESUMEN

Glucose detection is of significant importance in providing information to the human health management. However, conventional enzymatic glucose sensors suffer from a limited long-term stability due to the losing activity of the enzymes. In this work, the AuNi bimetallic aerogel with a well-defined nanowire network is synthesized and applied as the sensing nanomaterial in the non-enzymatic glucose detection. The three-dimensional (3D) hierarchical porous structure of the AuNi bimetallic aerogel ensures the high sensitivity of the sensor (40.34 µA mM-1 cm-2). Theoretical investigation unveiled the mechanism of the boosting electrocatalytic activity of the AuNi bimetallic aerogel toward glucose. A better adhesion between the sensing nanomaterial and the screen-printing electrodes (SPEs) is obtained after the introduction of Ni. On the basis of a wide linearity in the range of 0.1-5 mM, an excellent selectivity, an outstanding long-term stability (90 days) as well as the help of the signal processing circuit and an M5stack development board, the as-prepared glucose sensor successfully realizes remote monitoring of the glucose concentration. We speculate that this work is favorable to motivating the technological innovations of the non-enzymatic glucose sensors and intelligent sensing devices.


Asunto(s)
Técnicas Biosensibles , Técnicas Electroquímicas , Geles , Glucosa , Oro , Níquel , Técnicas Biosensibles/métodos , Níquel/química , Geles/química , Oro/química , Glucosa/análisis , Electrodos , Nanocables/química , Humanos , Límite de Detección
5.
Nat Commun ; 15(1): 4036, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38740750

RESUMEN

Microbial Ni2+ homeostasis underpins the virulence of several clinical pathogens. Ni2+ is an essential cofactor in urease and [NiFe]-hydrogenases involved in colonization and persistence. Many microbes produce metallophores to sequester metals necessary for their metabolism and starve competing neighboring organisms. The fungal metallophore aspergillomarasmine A (AMA) shows narrow specificity for Zn2+, Ni2+, and Co2+. Here, we show that this specificity allows AMA to block the uptake of Ni2+ and attenuate bacterial Ni-dependent enzymes, offering a potential strategy for reducing virulence. Bacterial exposure to AMA perturbs H2 metabolism, ureolysis, struvite crystallization, and biofilm formation and shows efficacy in a Galleria mellonella animal infection model. The inhibition of Ni-dependent enzymes was aided by Zn2+, which complexes with AMA and competes with the native nickelophore for the uptake of Ni2+. Biochemical analyses demonstrated high-affinity binding of AMA-metal complexes to NikA, the periplasmic substrate-binding protein of the Ni2+ uptake system. Structural examination of NikA in complex with Ni-AMA revealed that the coordination geometry of Ni-AMA mimics the native ligand, Ni-(L-His)2, providing a structural basis for binding AMA-metal complexes. Structure-activity relationship studies of AMA identified regions of the molecule that improve NikA affinity and offer potential routes for further developing this compound as an anti-virulence agent.


Asunto(s)
Proteínas Bacterianas , Níquel , Níquel/metabolismo , Níquel/química , Animales , Virulencia/efectos de los fármacos , Proteínas Bacterianas/metabolismo , Biopelículas/efectos de los fármacos , Zinc/metabolismo , Zinc/química , Mariposas Nocturnas/microbiología , Ureasa/metabolismo , Ureasa/antagonistas & inhibidores , Transporte Biológico
6.
BMC Oral Health ; 24(1): 564, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38745154

RESUMEN

BACKGROUND: Alterations in the mechanical properties of the materials utilized in orthodontic appliances could affect the working properties of the appliances, thereby affecting clinical progress and outcome. Numerous studies have confirmed the correlation between alloy corrosion and raised surface roughness, which has a direct impact on the working characteristics of orthodontic archwires. METHODS: Thirty nickel-titanium (NiTi) orthodontic archwires were utilized in this study. Patients were randomly selected and allocated into three groups according to the randomization plan; (The control group): subjects practiced regular oral hygiene; (The fluoride group): subjects used fluoride for intensive prophylaxis; (The chlorhexidine group): subjects used chlorhexidine. Representative samples were evaluated by SEM, and then SEM images with high resolution were examined using Image J software to determine the surface roughness and obtain the results for further statistical analysis. RESULTS: Our findings indicated a significant difference was found between the three groups regarding the anterior and posterior parts between the control and the two other groups and a non-significant difference between NaF and CHX groups. Overall, the p-value for group comparisons was 0.000 for both parts, indicating a highly significant difference especially between the control and NaF groups. CONCLUSION: Mouthwashes containing sodium fluoride demonstrated more significant surface alterations than the control and CHX groups and should be prescribed in accordance with orthodontic materials to reduce side effects.


Asunto(s)
Aleaciones , Clorhexidina , Aleaciones Dentales , Microscopía Electrónica de Rastreo , Níquel , Alambres para Ortodoncia , Fluoruro de Sodio , Propiedades de Superficie , Humanos , Fluoruro de Sodio/uso terapéutico , Clorhexidina/uso terapéutico , Corrosión , Aleaciones Dentales/química , Níquel/química , Titanio/química , Cariostáticos/uso terapéutico , Cariostáticos/química , Masculino , Femenino , Adulto Joven , Antisépticos Bucales/uso terapéutico , Antisépticos Bucales/química , Procesamiento de Imagen Asistido por Computador/métodos , Adolescente , Adulto , Higiene Bucal
7.
Luminescence ; 39(5): e4768, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38719590

RESUMEN

In this study, we synthesize nanostructured nickel oxide (NiO) and doped cobalt (Co) by combining nickel(II) chloride hexahydrate (NiCl2.6H2O) and sodium hydroxide (NaOH) as initial substances. We analyzed the characteristics of the product nanostructures, including their structure, optical properties, and magnetic properties, using various techniques such as x-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet absorption spectroscopy (UV-Vis), Fourier transform infrared (FTIR) spectroscopy, and vibrating sample magnetometers (VSM). The NiO nanoparticles doped with Co showed photocatalytic activity in degrading methylene blue (MB) dye in aqueous solutions. We calculated the degradation efficiencies by analyzing the UV-Vis absorption spectra at the dye's absorption wavelength of 664 nm. It was observed that the NiO-doped Co nanoparticles facilitated enhanced recombination and migration of active elements, which led to more effective degradation of organic dyes during photocatalysis. We also assessed the electrochemical properties of the materials using cyclic voltammetry (CV) and impedance spectroscopy in a 1 mol% NaOH solution. The NiO-modified electrode exhibited poor voltammogram performance due to insufficient contact between nanoparticles and the electrolyte solution. In contrast, the uncapped NiO's oxidation and reduction cyclic voltammograms displayed redox peaks at 0.36 and 0.30 V, respectively.


Asunto(s)
Cobalto , Electroquímica , Electrodos , Nanocompuestos , Níquel , Nanocompuestos/química , Níquel/química , Cobalto/química , Difracción de Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Luminiscencia , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Fenómenos Magnéticos , Nanopartículas/química , Luz , Catálisis , Óxidos/química , Azul de Metileno/metabolismo
8.
PLoS One ; 19(5): e0302972, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38722925

RESUMEN

Electroless nickel plating is a suitable technology for the hydrogen industry because electroless nickel can be mass-produced at a low cost. Investigating in a complex environment where hydrogen permeation and friction/wear work simultaneously is necessary to apply it to hydrogen valves for hydrogen fuel cell vehicles. In this research, the effects of hydrogen permeation on the mechanical characteristics of electroless nickel-plated free-cutting steel (SUM 24L) were investigated. Due to the inherent characteristics of electroless nickel plating, the damage (cracks and delamination of grain) and micro-particles by hydrogen permeation were clearly observed at the grain boundaries and triple junctions. In particular, the cracks grew from grain boundary toward the intergranualr. This is because the grain boundaries and triple junctions are hydrogen permeation pathways and increasing area of the hydrogen partial pressure. As a result, its surface roughness increased by a maximum of two times, and its hardness and adhesion strength decreased by hydrogen permeation. In particular, hydrogen permeation increased the friction coefficient of the electroless nickel-plated layer, and the damage caused by adhesive wear was significantly greater, increasing the wear depth by up to 5.7 times. This is believed to be due to the decreasing in wear resistance of the electroless nickel plating layer damaged by hydrogen permeation. Nevertheless, the Vickers hardness and the friction coefficient of the electroless nickel plating layer were improved by about 3 and 5.6 times, respectively, compared with those of the free-cutting steel. In particular, the electroless nickel-plated specimens with hydrogen embrittlement exhibited significantly better mechanical characteristics and wear resistance than the free-cutting steel.


Asunto(s)
Hidrógeno , Níquel , Acero , Hidrógeno/química , Níquel/química , Acero/química , Suministros de Energía Eléctrica , Propiedades de Superficie , Ensayo de Materiales
9.
J Chromatogr A ; 1726: 464961, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38723491

RESUMEN

The improvement of the stability and adsorption properties of materials on targets in sample pre-treatment has long been an objective. Extensive efforts have been made to achieve this goal. In this work, metal-organic framework Ni-MOF precursors were first synthesized by solvothermal method using polyvinylpyrrolidone (PVP) as an ideal templating agent, stabiliser and nanoparticle dispersant. After carbonization and acid washing, the nanoporous carbon microspheres material (Ni@C-acid) was obtained. Compared with the material without acid treatment (Ni@C), the specific surface area, pore volume, adsorption performance of Ni@C-acid were increased. Thanks to its excellent characteristics (high stability, abundant benzene rings), Ni@C-acid was used as fiber coatings in headspace solid-phase microextraction (HS-SPME) technology for extraction and preconcentration of polycyclic aromatic hydrocarbons (PAHs) prior to gas chromatography-flame ionization detector (GC-FID) analysis. The experimental parameters of extraction temperature, extraction time, agitation speed, desorption temperature, desorption time and sodium chloride (NaCl) concentration were studied. Under optimal experimental conditions, the wide linear range (0.01-30 ng mL-1), the good correlation coefficient (0.9916-0.9984), the low detection limit (0.003-0.011 ng mL-1), and the high enrichment factor (5273-13793) were obtained. The established method was successfully used for the detection of trace PAHs in actual tea infusions samples and satisfied recoveries ranging from 80.94-118.62 % were achieved. The present work provides a simple method for the preparation of highly stable and adsorbable porous carbon microsphere materials with potential applications in the extraction of environmental pollutants.


Asunto(s)
Carbono , Límite de Detección , Estructuras Metalorgánicas , Microesferas , Hidrocarburos Policíclicos Aromáticos , Microextracción en Fase Sólida , , Microextracción en Fase Sólida/métodos , Hidrocarburos Policíclicos Aromáticos/aislamiento & purificación , Hidrocarburos Policíclicos Aromáticos/análisis , Té/química , Carbono/química , Estructuras Metalorgánicas/química , Porosidad , Adsorción , Níquel/química , Níquel/aislamiento & purificación , Cromatografía de Gases/métodos , Reproducibilidad de los Resultados
10.
Sci Rep ; 14(1): 10032, 2024 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-38693156

RESUMEN

The primary objective of the present study was to produce metal complexes of H4DAP ligand (N,N'-((pyridine-2,6-diylbis(azanediyl))bis(carbonothioyl))dibenzamide) derived from 2,6-diaminopyridine and benzoyl isothiocyanate with either ML or M2L stoichiometry. There are three distinct coordination complexes obtained with the formulas [Co(H2DAP)]·H2O, [Ni2(H2DAP)Cl2(H2O)2]·H2O, and [Cu(H4DAP)Cl2]·3H2O. The confirmation of the structures of all derivatives was achieved through the utilization of several analytical techniques, including FT-IR, UV-Vis, NMR, GC-MS, PXRD, SEM, TEM analysis, and QM calculations. Aiming to analyze various noncovalent interactions, topological methods such as QTAIM, NCI, ELF, and LOL were performed. Furthermore, the capacity of metal-ligand binding was examined by fluorescence emission spectroscopy. An in vitro investigation showed that the viability of MDA-MB-231 and HepG-2 cells was lower when exposed to the manufactured Cu2+ complex, in comparison to the normal cis-platin medication. The compounds were further evaluated for their in vitro antibacterial activity. The Ni2+ complex has shown promising activity against all tested pathogens, comparable to the reference drugs Gentamycin and Ketoconazole. Furthermore, a computational docking investigation was conducted to further examine the orientation, interaction, and conformation of the recently created compounds on the active site of the Bcl-2 protein.


Asunto(s)
Cobalto , Complejos de Coordinación , Cobre , Isotiocianatos , Simulación del Acoplamiento Molecular , Níquel , Níquel/química , Cobre/química , Humanos , Isotiocianatos/química , Isotiocianatos/farmacología , Ligandos , Complejos de Coordinación/farmacología , Complejos de Coordinación/química , Complejos de Coordinación/síntesis química , Cobalto/química , Línea Celular Tumoral , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química
11.
PLoS One ; 19(5): e0302551, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38696475

RESUMEN

Recently developed Nickel-Titanium (NiTi) instruments with practical changes have resulted in safer instrumentation. In addition, topographical features on the file surface are a contributing factor to clinical durability. Therefore, this study aimed to investigate both the cyclic fatigue resistance and the roughness change of MTwo and Rotate instruments (VDW, Munich, Germany). Each instrument (n = 6/each group) was scanned with an atomic force microscopy prior to and after instrumentation. In addition, cyclic fatigue testing was conducted for each instrument (n = 11/each group) with stainless-steel blocks, including 45°-60°-90° degrees of curvature milled to the instruments' size. The roughness parameters increased for both systems after instrumentation (p<0.05). Both systems presented an increased roughness following instrumentation (p<0.05). The cyclic fatigue resistance was lowest at 90° for both systems (p<0.05), whereas the Rotate files presented a higher resistance than that of the Mtwo files (p<0.05). Compared to the Mtwo files, Rotate files presented better resistance, while the resistance decreased as the curvature increased.


Asunto(s)
Níquel , Propiedades de Superficie , Titanio , Titanio/química , Níquel/química , Microscopía de Fuerza Atómica , Ensayo de Materiales , Preparación del Conducto Radicular/instrumentación
12.
Molecules ; 29(10)2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38792033

RESUMEN

Copper(II), nickel(II) and zinc(II) complexes of various peptide fragments of tau protein were studied by potentiometric and spectroscopic techniques. All peptides contained one histidyl residue and represented the sequences of tau(91-97) (Ac-AQPHTEI-NH2), tau(385-390) (Ac-KTDHGA-NH2) and tau(404-409) (Ac-SPRHLS-NH2). Imidazole-N donors of histidine were the primary metal binding sites for all peptides and all metal ions, but in the case of copper(II) and nickel(II), the deprotonated amide groups were also involved in metal binding by increasing pH. The most stable complexes were formed with copper(II) ions, but the presence of prolyl residues resulted in significant changes in the thermodynamic stability and speciation of the systems. It was also demonstrated that nickel(II) and especially zinc(II) complexes have relatively low thermodynamic stability with these peptides. The copper(II)-catalyzed oxidation of the peptides was also studied. In the presence of H2O2, the fragmentation of peptides was detected in all cases. In the simultaneous presence of H2O2 and ascorbic acid, the fragmentation of the peptide is less preferred, and the formation of 2-oxo-histidine also occurs.


Asunto(s)
Complejos de Coordinación , Cobre , Níquel , Fragmentos de Péptidos , Zinc , Proteínas tau , Níquel/química , Cobre/química , Zinc/química , Proteínas tau/química , Complejos de Coordinación/química , Fragmentos de Péptidos/química , Oxidación-Reducción , Histidina/química , Concentración de Iones de Hidrógeno , Peróxido de Hidrógeno/química , Termodinámica
13.
Biosensors (Basel) ; 14(5)2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38785712

RESUMEN

Nanostructured metal oxides (NMOs) provide electrical properties such as high surface-to-volume ratio, reaction activity, and good adsorption strength. Furthermore, they serve as a conductive substrate for the immobilization of biomolecules, exhibiting notable biological activity. Capitalizing on these characteristics, they find utility in the development of various electrochemical biosensing devices, elevating the sensitivity and selectivity of such diagnostic platforms. In this review, different types of NMOs, including zinc oxide (ZnO), titanium dioxide (TiO2), iron (II, III) oxide (Fe3O4), nickel oxide (NiO), and copper oxide (CuO); their synthesis methods; and how they can be integrated into biosensors used for medical diagnosis are examined. It also includes a detailed table for the last 10 years covering the morphologies, analysis techniques, analytes, and analytical performances of electrochemical biosensors developed for medical diagnosis.


Asunto(s)
Técnicas Biosensibles , Técnicas Electroquímicas , Nanoestructuras , Humanos , Óxidos/química , Níquel/química , Titanio/química , Óxido de Zinc/química , Metales/química , Cobre/análisis , Cobre/química
14.
Bioresour Technol ; 402: 130844, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38754560

RESUMEN

In this study, a novel magnetic Ni-Fe2O3-C catalyst combined with electromagnetic induction heating in biomass steam gasification was proposed to enhance H2 production. Better catalytic performance for H2 production was observed with the Ni-Fe2O3-C catalyst under induction heating, resulting in an increase in H2 yield from 735.1 to 2271.2 mL/g-biomass (a 209.1 % enhancement). SEM, TGA and XRD analysis demonstrated a significant decrease in coking deposition, caking, and particle agglomeration of the Ni-Fe2O3-C catalyst under induction heating, while maintaining more active sites. Importantly, the benefits of induction heating were also applicable to different magnetic catalysts like Ni-Al2O3-C, Ni-ZrO2-C, and Ni-MgO-C. Experimental results revealed a logarithmic correlation between the increase in H2 yields due to induction heating and the magnetic saturation (Ms) of the catalysts. The Ni-Fe2O3-C catalyst, with a high Ms of 50.9 emu/g, showed the highest catalytic activity for H2 production under induction heating in this study.


Asunto(s)
Biomasa , Compuestos Férricos , Hidrógeno , Níquel , Vapor , Catálisis , Hidrógeno/química , Níquel/química , Compuestos Férricos/química , Calor , Calefacción , Difracción de Rayos X , Fenómenos Electromagnéticos
15.
Environ Sci Pollut Res Int ; 31(24): 35069-35082, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38714619

RESUMEN

The increasing concentration of CO2 and CH4 in the environment is a global concern. Tri-reforming of methane (TRM) is a promising route for the conversion of these two greenhouse gases to more valuable synthesis gas with an H2/CO ratio of 1.5-2. In this study, a series of Zr-MOF synthesized via the solvothermal method and impregnation technique was used to synthesize the nickel impregnated on MOF-derived ZrO2 catalyst. The catalyst was characterized by various methods, including N2-porosimetry, X-ray diffraction (XRD), temperature programmed reduction (TPR), CO2-temperature programmed desorption (CO2-TPD), thermo-gravimetric analysis (TGA), chemisorption, field-emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM). Characterization results confirmed the formation of the Zr-MOF and nickel metal dispersed on MOF-derived ZrO2. Further, the tri-reforming activity of the catalyst developed was evaluated in a downflow-packed bed reactor. The various catalysts were screened for TRM activity at different temperatures (600-850 °C). Results demonstrated that TRM was highly favorable over the NZ-1000 catalyst due to its desirable physicochemical properties, including nickel metal surface area (2.3 m2/gcat-1), metal dispersion (7.1%), and nickel metal reducibility (45%), respectively. Over the NZ-1000 catalyst, an optimum H2/CO ratio of ~ 1.6-2 was achieved at 750 °C, and it was stable for a longer period of time.


Asunto(s)
Metano , Níquel , Circonio , Metano/química , Catálisis , Níquel/química , Circonio/química , Estructuras Metalorgánicas/química , Dióxido de Carbono/química , Difracción de Rayos X
16.
Int J Biol Macromol ; 269(Pt 2): 132156, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38729480

RESUMEN

Reasonable design of non-noble metal catalysts with hollow open structure for hydrodeoxygenation (HDO) of lignin derivatives to value-added chemicals is of great significance but challenging. Herein, a novel MOF-derived multilayer hollow sphere coated nickel­tungsten bimetallic catalyst (Ni2-WOx@CN-700) was fabricated via by confined pyrolysis strategy using bimetallic MOFs as a self-sacrificial template, which exhibits robust activity for the typical model HDO of vanillin to 2-methoxy-4-methylphenol (Yield of 100 % at 140 °C for no less than 10 cycles). The characterizations revealed that WOx facilitated the dispersion of Ni nanoparticles and adjusted the acidic capacity of the catalyst through the formed Ni-WOx heterojunction. Density functional theory (DFT) calculations confirms that WOx species enhanced the electron-rich nature of the active sites, while the adsorption energies of H2 and vanillin on Ni-WOx decreased from -0.572 eV and - 0.622 eV on Ni to -3.969 eV and - 4.922 eV, respectively. These results further indicated that the high activity of Ni2-WOx@CN-700 was attributed to the Ni-WOx heterojunction. Based on the characterizations and the thermodynamic calculations, the reaction mechanism was proposed. In addition, the catalyst shows good substrate universality, which enables its good commercial application prospect.


Asunto(s)
Benzaldehídos , Níquel , Catálisis , Níquel/química , Benzaldehídos/química , Tungsteno/química , Lignina/química , Termodinámica , Estructuras Metalorgánicas/química , Adsorción , Teoría Funcional de la Densidad
17.
Int J Biol Macromol ; 269(Pt 1): 132075, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38705317

RESUMEN

Carbonic anhydrase (CA) has a promising application as a green and efficient biocatalyst for CO2 capture, and many successful cases of immobilizing CA have been reported. However, CA antifouling coatings on metal for CO2 sequestration have rarely been reported. Herein, dimeric CA from Sulfurihydrogenibium azorense (SazCA) with a ferritin tag, which was prepared by low-speed centrifugation with high yield, was adopted as a free enzyme and encapsulated in the sol-gel silica. The silica-immobilized CAs were dispersed into the commercialized metal-antifouling epoxy resin paint to obtain CA coated nickel foams, which had excellent stability, with 90 % and 67 % residual activity after 28 days of incubation at 30 °C and 60 °C, respectively. The CA coated nickel foams remained 60 % original activity after 6 cycles of use within 28 days. Then, a CA-microalgae carbon capture device was constructed using the CA coated nickel foams and Chlorella. The growth rate of Chlorella was significantly increased and the biomass of Chlorella increased by 29 % compared with control after 7 days of incubation. Due to the simple and cost-effective preparation process, sustainable and efficient CO2 absorption, this easy-to-scale up CA coated nickel foam has great potential in CA assisted microalgae-based CO2 capture and carbon neutrality.


Asunto(s)
Dióxido de Carbono , Anhidrasas Carbónicas , Enzimas Inmovilizadas , Microalgas , Dióxido de Silicio , Dióxido de Carbono/química , Dióxido de Silicio/química , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Anhidrasas Carbónicas/metabolismo , Anhidrasas Carbónicas/química , Níquel/química , Resinas Epoxi/química , Incrustaciones Biológicas/prevención & control
18.
Mikrochim Acta ; 191(5): 252, 2024 04 09.
Artículo en Inglés | MEDLINE | ID: mdl-38589716

RESUMEN

A flexible, wearable, non-invasive contact lens sensor utilizing nickel-cobalt metal-organic framework (Ni-Co-MOF) based hydrogel is introduced for urea monitoring in tear samples. The synthesized Ni-Co-MOF hydrogel exhibits a porous structure with interconnected voids, as visualized by Scanning Electron Microscopy (SEM). Detailed structural and vibrational properties of the material were characterized using X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, and Raman spectroscopy. The developed Ni-Co-MOF hydrogel sensor showcases a detection limit of 0.445 mM for urea within a linear range of 0.5-70 mM. Notably, it demonstrates exceptional selectivity, effectively distinguishing against interfering species like UA, AA, glucose, dopamine, Cl-, K+, Na+, Ca2+, and IgG. The enhanced electrocatalytic performance of the Ni-Co-MOF hydrogel electrode is attributed to the presence of Ni and Co, fostering Ni2+ oxidation on the surface and forming a Co2+ complex that acts as a catalyst for urea oxidation. The fabricated sensor exhibits successful detection and retrieval of urea in simulated tear samples, showcasing promising potential for bioanalytical applications. The binder-free, non-toxic nature of the Ni-Co-MOF hydrogel sensor presents exciting avenues for future utilization in non-enzymatic electrochemical sensing, including applications in wearable devices, point-of-care diagnostics, and personalized healthcare monitoring.


Asunto(s)
Estructuras Metalorgánicas , Dispositivos Electrónicos Vestibles , Níquel/química , Estructuras Metalorgánicas/química , Urea , Cobalto , Hidrogeles
19.
Mikrochim Acta ; 191(5): 267, 2024 04 16.
Artículo en Inglés | MEDLINE | ID: mdl-38627300

RESUMEN

A ternary hierarchical hybrid Ni@CoxSy/poly(3,4-ethylenedioxythiophene)-reduced graphene oxide (Ni@CoxSy/PEDOT-rGO) is rationally designed and in situ facilely synthesized as electrocatalyst to construct a binder-free sensing platform for non-enzymatic glucose monitoring through traditional electrodeposition procedure. The as-prepared Ni@CoxSy/PEDOT-rGO presents unique hierarchical structure and multiple valence states as well as strong and robust adhesion between Ni@CoxSy/PEDOT-rGO and GCE. Profiting from the aforementioned merits, the sensing platform constructed under optimal conditions achieved a wide detection range (0.2 µM ~ 2.0 mM) with high sensitivity (1546.32 µA cm-2 mM-1), a rapid response time (5 s), an ultralow detection limit (0.094 µM), superior anti-interference performance, excellent reproducibility and considerable stability. Furthermore, the sensor demonstrates an acceptable accuracy and appreciable recoveries ranging from 90.0 to 102.0% with less than 3.98% RSD in human blood serum samples, indicating the prospect of the sensor for the real samples analysis. It will provide a strategy to rationally design and fabricate ternary hierarchical hybrid as nanozyme for glucose assay.


Asunto(s)
Glucemia , Compuestos Bicíclicos Heterocíclicos con Puentes , Cobalto , Grafito , Níquel , Polímeros , Humanos , Níquel/química , Glucemia/análisis , Reproducibilidad de los Resultados , Automonitorización de la Glucosa Sanguínea , Glucosa/análisis
20.
Waste Manag ; 182: 63-73, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38640752

RESUMEN

The incineration bottom ash (IBA) was impregnated with nickel to catalyze toluene (tar surrogate) steam reforming. A toluene conversion of >80 % was achieved at 800℃ without activity decay in a 100-h test for 15 %Ni/IBA. An activation stage was observed for Ni/IBA catalysts in the initial 50 âˆ¼ 400 min under different reaction conditions. A series of experiments and characterizations were performed to explore the possible mechanisms for the activation. It was found that the iron species in IBA gradually migrated to the catalyst surface and formed a Ni-FeOx complex owing to the metal-support interaction. The synergy of Ni-FeOx played an important role in improving the activity of Ni/IBA due to the enhanced lattice oxygen activity. Additionally, Ni/IBA catalysts showed a much lower coke deposition rate than Ni/Al2O3 (1.12 vs. 3.45 mg-C/gcat∙h) because of the variable states of FeOx and the abundant basic sites caused by the alkali and alkaline earth metals contained in IBA.


Asunto(s)
Compuestos Férricos , Incineración , Níquel , Níquel/química , Catálisis , Compuestos Férricos/química , Incineración/métodos , Tolueno/química , Ceniza del Carbón/química
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