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1.
Food Chem ; 430: 136853, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37541041

RESUMO

In the present work, a cobalt molybdate (CoMoO4) hollow spheres-incorporated graphitic carbon nitride (g-CN) composite is prepared for the electrochemical detection of dimetridazole (DZ). The synergistic effect between the hollow-structured CoMoO4 and g-CN nanosheets facilitates the transportation of electrons through kinetic barriers, thereby providing a high electrical conductivity with increased electroactive sites. The proposed CoMoO4@g-CN-modified electrode displayed a wide linear range (0.001-492.77 µM) and a lower detection limit (LOD: 0.4 nM) for the determination of DZ through the amperometry (i-t) method. In addition, the CoMoO4@g-CN-modified electrode achieved good operational stability, anti-interfering ability (five-fold excess amount of co-interfering compounds) and reproducibility. These results demonstrate the increased electrocatalytic activity of CoMoO4@g-CN modified glassy carbon electrode (GCE) towards the detection of DZ in food samples with satisfactory recovery ranges.


Assuntos
Cobalto , Dimetridazol , Cobalto/química , Reprodutibilidade dos Testes , Carbono/química , Técnicas Eletroquímicas/métodos , Eletrodos
2.
Food Chem ; 435: 137651, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37806196

RESUMO

Luteolin (Lu) is a dietary flavonoid that has attracted much attention due to its multiple health benefis effects. Herein, an ultrasensitive electrochemical sensor for Lu was constracted based on cobalt-doped microporous/mesoporous carbon (MMC) encapsulated peanut-like Fe2O3 composite. The FeOx-Co-MMC composite was obtained by pyrolyzing a precursor named Fe2O3-Co-microporous/mesoporous dopamine (Fe2O3-Co-MMPDA) which was synthesized by a soft template method. Under optimized conditions, the sensor exhibited good detection of Lu with a low limit of detection (LOD) of 0.031 nM and a wide linear range from 0.05 to 1000 nM in detecting Lu. It also demonstrated good reproducibility (RSD = 3.16%), stability (RSD = 2.34%), and anti-interference properties. The sensor successfully detected Lu in real food samples such as honeysuckle with recoveries ranging from 96.1% to 104.8% (RSD <3%, n = 3). The present study provides an alternative method for Lu detection in food.


Assuntos
Carbono , Cobalto , Carbono/química , Cobalto/química , Arachis , Luteolina , Técnicas Eletroquímicas/métodos , Reprodutibilidade dos Testes , Eletrodos
3.
Environ Pollut ; 340(Pt 2): 122788, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37879550

RESUMO

Bio-based materials facilitate greener approach to engineering novel materials with multifunctional properties for various applications including water treatment. In this study, we extracted gliadin from wheat gluten using alcoholic solvent. The aggregation limitations of gliadin protein were overcome by functionalisation with metal oxides (MOs) TiO2, AgFe2O3 and AgFe-TiO2 prepared by chemical precipitations. The novel composites were characterised by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), thermogravimetry analysis (TGA), Brunauer Emmet-Teller (BET), and zeta potential. The multifunctionality of MOs-gliadin composites was tested through toxic Escherichia coli (E. coli) inactivation and Co2+ adsorption from water. The antibacterial results showed excellent inhibition under both dark and light conditions. The maximum Co2+ uptake, 101 mg/g was reached with TiO2@gliadin after 24 h and best fitted the Langmuir isotherm model. The adsorption process followed pseudo-second order model with an equilibrium adsorption capacity, qe2= 89.86 mg/g closer to the experimental data. Thermodynamic investigations indicated that ΔG°=-9.677kJ/mol,ΔH°=-123kJ/mol,and ΔS°=0.490J.K/mol, respectively, suggesting that adsorption was spontaneous and endothermic. The regenerated TiO2@gliadin composite was still efficient after five consecutive cycles. This study demonstrates that MOs-gliadin blended composites are sustainable for water purification.


Assuntos
Gliadina , Poluentes Químicos da Água , Escherichia coli , Cobalto/análise , Termodinâmica , Óxidos/farmacologia , Adsorção , Espectroscopia de Infravermelho com Transformada de Fourier , Cinética , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio
4.
Sci Total Environ ; 906: 167385, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37777136

RESUMO

BACKGROUND: Immunoglobulin E (IgE) is a diagnostic biomarker for allergic diseases. While some metal exposure has been found to be associated with allergic diseases, there are still a lot of knowledge gaps regarding the relationship between metal exposure and allergen-specific IgE antibodies, particularly in adults. METHODS: We included a total of 1433 adult participants from the 2005-2006 National Health and Nutrition Examination Survey (NHANES), all of whom had concentrations of 10 metals (including Barium (Ba), Cadmium (Cd), Cobalt (Co), Cesium (Cs), Molybdenum (Mo), Lead (Pb), Antimony (Sb), Thallium (Tl), Tungsten (Tu), and Uranium (Ur)) in urine, as well as measurements of 19 allergen-specific IgE and total IgE antibodies. Linear regression, logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) were used to estimate associations between metals and total and allergen-specific IgE. RESULTS: Linear regression models revealed a positive correlation between Pb and Cd levels and the total IgE levels. Furthermore, the WQS and BKMR models suggested a positive association between mixed metals and total IgE levels, with the WQS model highlighting Pb and Cd as the major contributors. Logistic regression models showed positive correlations between Pb and food sensitization, Ur and plant sensitization, negative correlations between Cs and plant sensitization, Co and dust mite and pet sensitization, Mo and dust mite and cockroach sensitization, and Tl and mold sensitization. Moreover, the BKMR results indicated a statistically significant negative correlation between mixed metals and mold sensitization. CONCLUSION: According to the research findings, exposure to metals is associated with total and allergen-specific IgE in American adults. Further assessment of these relationships is necessary in representative populations of other countries.


Assuntos
Hipersensibilidade , Urânio , Adulto , Humanos , Inquéritos Nutricionais , Cádmio , Teorema de Bayes , Chumbo , Alérgenos , Cobalto , Molibdênio , Tálio , Fungos , Césio , Imunoglobulina E
5.
Bioresour Technol ; 392: 130011, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37956946

RESUMO

Cobalt Iron -layered double hydroxide (CoFe-LDH) nano sheets were attached to Nickel-metal organic frameworks (Ni-MOF) by utilizing hydrothermal reaction method, and CoFe-LDH@Ni-MOF was synthesized and worked as the cathode catalyst in microbial fuel cell. The surface of this composite material provided generous electrochemical active sites, consisting of wrinkled strips of CoFe-LDH adhering to a lamellar structure of Ni-MOF. In terms of the maximum output power density, CoFe-LDH@Ni-MOF as the catalyst was 211 mW/m2, 2.54 times higher than that of Ni-MOF (83 mW/m2), and it was stable at about 225 mV for 150 h. CoFe-LDH@Ni-MOF showed high oxygen reduction reaction capability and high specific surface area, and the electron transfer rate was accelerated. This work might set the stage for the development and utilization of fuel cell cathode catalysts.


Assuntos
Fontes de Energia Bioelétrica , Estruturas Metalorgânicas , Níquel , Eletrodos , Hidróxidos , Ferro , Oxigênio , Cobalto
6.
Sci Total Environ ; 907: 167861, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-37852494

RESUMO

The increasing applications of silver nanomaterials (nano-Ag) and their inevitable release posed great potential risks to aquatic organisms and ecosystems. Considerable attention has been attracted on their behaviors and transformations, which were critically important for their subsequent biological toxicities and ecological effects. Therefore, the summary of the recent efforts on the environmental behavior of nano-Ag would be beneficial for understanding the environmental fate and accurate risk assessment. This review summarized the studies on various physical, chemical and biological transformations of nano-Ag, meanwhile, the influencing factors (including the intrinsic properties and environmental conditions) and related mechanisms were highlighted. Surface structure and facets of nano-Ag, abiotic conditions and natural freeze-thaw cycle processes could affect the transformations of nano-Ag under different environmental scenarios (including freshwater, seawater and wastewater). The interactions with co-present components, such as chemicals and other particles, impacted the multiple processes of nano-Ag. Besides, the contradictory effects and mechanisms by several environmental factors were summarized. Lastly, the key knowledge gaps and some aspects that deserve further investigation were also addressed. Therefore, the current review aimed to provide an overall analysis of transformation processes of nano-Ag, which will provide more available information and pave the way for the future research areas.


Assuntos
Nanopartículas Metálicas , Nanoestruturas , Prata/toxicidade , Prata/química , Ecossistema , Nanoestruturas/toxicidade , Água Doce/química , Água do Mar/química , Cobalto , Nanopartículas Metálicas/química
7.
Methods Mol Biol ; 2730: 203-210, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37943460

RESUMO

Cobalt-mediated radical polymerization (CMRP) enables the preparation of both short and long polymers from acrylic and vinyl ester monomers with low dispersity. Here we describe the synthesis, purification, and characterization of polymeric mimics of ice-binding proteins based on the water-soluble polymer poly(vinyl alcohol) by CMRP. Block copolymers of poly(vinyl alcohol) and poly(acrylic acid) were prepared from the precursor copolymers poly(vinyl acetate)-b-poly(acrylonitrile) upon hydrolysis. Copolymers comprising up to hundreds of monomers and dispersities Mw/Mn < 1.3 were produced by this method.


Assuntos
Acrilonitrila , Proteínas de Transporte , Gelo , Álcool de Polivinil , Polímeros , Cobalto
8.
PLoS One ; 18(11): e0287322, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37992124

RESUMO

In this study, zinc-oxide (ZnO) nanoparticles (NPs) doped with cobalt (Co) were synthesized using a simple coprecipitation technique. The concentration of Co was varied to investigate its effect on the structural, morphological, optical, and dielectric properties of the NPs. X-ray diffraction (XRD) analysis confirmed the hexagonal wurtzite structure of both undoped and Co-doped ZnO-NPs. Scanning electron microscopy (SEM) was used to examine the morphology of the synthesized NPs, while energy-dispersive X-ray spectroscopy (EDX) was used to verify their purity. The band gap of the NPs was evaluated using UV-visible spectroscopy, which revealed a decrease in the energy gap as the concentration of Co2+ increased in the ZnO matrix. The dielectric constants and AC conductivity of the NPs were measured using an LCR meter. The dielectric constant of the Co-doped ZnO-NPs continuously increased from 4.0 × 10-9 to 2.25 × 10-8, while the dielectric loss decreased from 4.0 × 10-8 to 1.7 × 10-7 as the Co content increased from 0.01 to 0.07%. The a.c. conductivity also increased with increasing applied frequency. The findings suggest that the synthesized Co-doped ZnO-NPs possess enhanced dielectric properties and reduced energy gap, making them promising candidates for low-frequency devices such as UV photodetectors, optoelectronics, and spintronics applications. The use of a cost-effective and scalable synthesis method, coupled with detailed material characterization, makes this work significant in the field of nanomaterials and device engineering.


Assuntos
Nanopartículas , Óxido de Zinco , Óxido de Zinco/química , Nanopartículas/química , Óxidos , Cobalto/química , Difração de Raios X
9.
Yakugaku Zasshi ; 143(11): 889-895, 2023.
Artigo em Japonês | MEDLINE | ID: mdl-37914335

RESUMO

The transition-metal-catalyzed cycloisomerization of unsaturated compounds, such as alkynes, alkenes, allenes, and nitriles, is a powerful tool for constructing polycyclic frameworks found in many biologically active natural products and pharmaceuticals. However, this approach predominantly relies on precious transition metals, such as rhodium and iridium. Thus, the development of cycloisomerization reactions using less expensive, less toxic, and environmentally friendly transition metals that are abundantly found in the earth has attracted considerable attention in recent years. In this article, we reviewed our recent studies on the synthesis of various polycyclic compounds via cycloisomerization enabled by the cobalt/photoredox dual catalysis. Our research has demonstrated the excellent efficiency of the cobalt/photoredox dual catalyst system for the cycloisomerization of 1,6-diyne derivatives. We constructed tricyclic cyclohexadiene frameworks, which are found in many biologically active natural products such as 11-O-debenzoyltashironin, perforanoid A, and jiadifenolide, using 1,6,11-enediynes as substrates for the cobalt-catalyzed cycloisomerization. Using a chiral ligand, (S)-Segphos, we achieved an enantioselective reaction that allowed access to enantio-enriched tricyclic cyclohexadiene products. Furthermore, we discovered that a novel cascade cyclization of 1,6-diynyl esters, enabled by the cobalt/photoredox dual catalysis, provided various cyclic compounds via the formation of vinylallene intermediates.


Assuntos
Produtos Biológicos , Cobalto , Estrutura Molecular , Catálise , Cicloexenos
10.
Int J Mol Sci ; 24(21)2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37958532

RESUMO

Alkaline aqueous zinc-ion batteries possess a wider potential window than those in mildly acidic systems; they can achieve high energy density and are expected to become the next generation of energy storage devices. In this paper, a hollow porous P-NiCo2O4@Co3O4 nanoarray is obtained by ion etching and the calcination and phosphating of ZiF-67, which is directly grown on foam nickel substrate, as a precursor. It exhibits excellent performance as a cathode material for alkaline aqueous zinc-ion batteries. A high discharge specific capacity of 225.3 mAh g-1 is obtained at 1 A g-1 current density, and it remains 81.9% when the current density is increased to 10 A g-1. After one thousand cycles of charging and discharging at 3 A g-1 current density, the capacity retention rate is 88.8%. Even at an excellent power density of 25.5 kW kg-1, it maintains a high energy density of 304.5 Wh kg-1. It is a vital, promising high-power energy storage device for large-scale applications.


Assuntos
Líquidos Corporais , Zinco , Porosidade , Cobalto
11.
Environ Sci Pollut Res Int ; 30(50): 109546-109558, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37924173

RESUMO

The rapid trend of industrialization and urbanization can lead to greater exposure of the general population to chromium, cobalt, and nickel. Their total body burden from all routes of recent exposure, as well as interindividual variability in exposure levels, metabolism, and excretion rates, are reflected in the blood metal concentrations. The main goals in this study were as follows: observing the reference levels of chromium, cobalt, and nickel in the blood of the population living in Belgrade, identification of individual and sociodemographic factors that most affect their blood levels, and comprehension of recent exposure to chromium, cobalt, and nickel. Blood was sampled from 984 participants, voluntary blood donors, who agreed to participate in this study. Individual and sociodemographic data were collected using questionnaire adapted for different subpopulations. Blood metal analyses were measured using ICP-MS method (7700×, Agilent, USA). Our study provided reference values of chromium, cobalt, and nickel in blood for adult population (18-65 years) and confirmed that blood cobalt and nickel levels were mostly influenced by age and gender, and age, respectively. Furthermore, weight status affected blood chromium and cobalt levels, while national origin affected blood chromium levels. The present study highlighted the importance of human biomonitoring studies to monitor exposure status and identify subpopulations with increased exposure to chromium, cobalt, and nickel.


Assuntos
Cromo , Níquel , Adulto , Humanos , Níquel/análise , Cromo/análise , Cobalto/análise , Sérvia , Metais/análise
12.
ACS Appl Bio Mater ; 6(11): 5018-5029, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37914190

RESUMO

Self-assembled metal-ion cross-linked multifunctional hydrogels are gaining a lot of attention in the fields of biomedical and biocatalysis. Herein, we report a heat-triggered metallogel that was spontaneously formed by the self-assembly of adenosine 5'-monophosphate (AMP) and cobalt chloride, accompanied by a color transition depicting an octahedral to tetrahedral transition at high temperature. The hydrogel shows excellent stability in a wide pH window from 1 to 12. The metallogel is being exploited as a multienzyme mimic, exhibiting pH-responsive catalase and peroxidase activity. Whereas catalase mimicking activity was demonstrated by the hydrogel under neutral and basic conditions, it shows peroxidase mimicking activity in an acidic medium. The multifunctionality of the synthesized metallogel was further demonstrated by phenoxazinone synthase-like activities. Owing to its catalase-mimicking activity, the metallogel could effectively reduce the oxidative stress produced in cells due to excess hydrogen peroxide by degrading H2O2 to O2 and H2O under physiological conditions. The biocompatible metallogel could prevent cell apoptosis by scavenging reactive oxygen species. A green and simple synthetic strategy utilizing commonly available biomolecules makes this metallogel highly attractive for catalytic and biomedical applications.


Assuntos
Hidrogéis , Peróxido de Hidrogênio , Catalase , Cobalto , Concentração de Íons de Hidrogênio
13.
Nat Commun ; 14(1): 7439, 2023 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-37978196

RESUMO

γ-Amino acids and peptides analogues are common constituents of building blocks for numerous biologically active molecules, pharmaceuticals, and natural products. In particular, γ-amino acids are providing with better metabolic stability than α-amino acids. Herein we report a multicomponent carbonylation technology that combines readily available amides, alkenes, and the feedstock gas carbon monoxide to build architecturally complex and functionally diverse γ-amino acid derivatives in a single step by the implementation of radical relay catalysis. This transformation can also be used as a late-stage functionalization strategy to deliver complex, advanced γ-amino acid products for pharmaceutical and other areas.


Assuntos
Alcenos , Cobalto , Alcenos/química , Peptídeos/química , Aminoácidos/química , Aminas/química , Catálise , Preparações Farmacêuticas
14.
Toxicol Appl Pharmacol ; 480: 116746, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37931756

RESUMO

BACKGROUND: Cancers that primarily affect women in the US include breast, uterine, and cervical cancers. There may be associations between these different types of cancer in women and environmental pollutant exposure. PURPOSE: This study aimed to assess seven species of arsenic, six polycyclic aromatic hydrocarbon (PAH) compounds, and fourteen different metal concentrations in urine and their correlation with cancer among women. METHODS: We conducted a cross-sectional analysis using 2011--2012 to 2015-2016 National Health and Nutrition Examination Survey data (n = 4,956) and logistic regression modeling of the complex weighted survey design. RESULTS: Breast cancer was inversely correlated with arsenocholine (3rd quantile), monomethylarsonic acid (4th quantile), manganese (4th quantile), and antimony (3rd, 4th quantiles). Cervical cancer was inversely correlated with 3-hydroxyfluorene (3rd quantile), molybdenum (2nd, 4th quantiles), antimony (3rd quantile), tin (4th quantile), and thallium (4th quantile) exposure and positively associated with arsenic acid (3rd quantile), arsenobetaine (2nd, 4th quantiles). Uterine cancer was correlated with 1-hydroxynaphthalene (3rd, 4th quantiles), 2-hydroxynaphthalene (4th quantile), 1-hydroxyphenathrene (2nd, 4th quantiles), 1-hydroxypyrene (3rd quantile), cobalt (2nd, 3rd quantiles) and inversely with mercury (4th quantile). CONCLUSION: This study determined breast cancer and arsenic and some metal species exposure, indicating an inverse association. Arsenic acid and arsenobetaine exposure showed a positive correlation with cervical cancer. For uterine cancer, the correlations for the PAH compounds and cobalt showed a positive correlation, and the arsenic species and mercury were inversely associated. Further research is required to establish or refute the findings.


Assuntos
Arsênio , Neoplasias da Mama , Poluentes Ambientais , Mercúrio , Hidrocarbonetos Policíclicos Aromáticos , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/induzido quimicamente , Neoplasias do Colo do Útero/epidemiologia , Antimônio , Inquéritos Nutricionais , Estudos Transversais , Metais , Poluentes Ambientais/urina , Cobalto , Neoplasias da Mama/induzido quimicamente , Neoplasias da Mama/epidemiologia , Biomarcadores/urina
15.
PLoS One ; 18(10): e0275374, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37874843

RESUMO

The durability of dental restorations is highly determined by an accurate marginal fit, which is in turn affected by the high temperature of porcelain firing. Information is inadequate about the marginal adaptation of metal-ceramic restorations fabricated by soft metal milling technologies after repeated firings. This study aimed to compare the effect of repeated ceramic firings on the marginal fit of copings fabricated from cobalt-chromium through soft metal milling and a conventional nickel-chromium casting alloy. A single standard brass die was designed, machined, and scanned, based on which, 20 frameworks were designed and fabricated through either soft metal milling or conventional casting (n = 10 per group) and porcelain veneered. The vertical marginal fit of the metal copings was measured after 3, 5, and 7 firing cycles by using a digital microscope on 16 points around the finish line of the metal die at ×80 magnification. The data were analyzed through repeated measures ANOVA and independent t-test (α = 0.05). The marginal fit of neither metal group was significantly affected by the number of firing cycles (P = 0.747). However, the marginal discrepancy was statistically lower in the soft metal milling group than that in the casting group (P<0.001). Repeated porcelain firings did not significantly affect the marginal fit of either alloy and remained within the clinically acceptable range after firings. However, the milled alloy had superior marginal fit regardless of the number of firing cycles.


Assuntos
Desenho Assistido por Computador , Porcelana Dentária , Ligas Metalo-Cerâmicas , Ligas de Cromo , Cobalto , Cromo , Planejamento de Prótese Dentária
16.
Anal Chim Acta ; 1280: 341817, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37858571

RESUMO

The self-powered sensor (SPS) is a sensor method that does not require the external power source and has the potential for portable detection of environmental contaminants. In this work, for the first time, a biomolecule-free SPS for detection of ultra-trace triazine endocrine disruptor atrazine (ATZ) with high sensitivity and selectivity is constructed using a glucose oxidase (GOD)-like cobalt metal-organic framework (Co-MOF) nanozyme-modified high-performance anode and a molecularly imprinted cathode. By modulating the size and morphology of the prepared materials, Co-MOF nanozyme with superior GOD-like property (Michaelis constant Km = 15.8 mM) has been obtained and modified at the anode to catalyze glucose oxidation with high efficiency and provide energy continuously and stably for the SPS. The separation mode of anodic energy supply-cathodic recognition ensures the recognition effect without affecting the catalytic characteristic of Co-MOF and the output signal of the SPS. The designed SPS has a wide linear range of 1 pM-100 nM and a detection limit as low as 0.65 pM, as well as superior selectivity and good stability. The present work provides a promising approach for the design of self-powered sensors which can be extended to detection of a wider range of environmental pollutants.


Assuntos
Atrazina , Estruturas Metalorgânicas , Glucose Oxidase , Cobalto , Catálise
17.
J Mech Behav Biomed Mater ; 148: 106196, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37875039

RESUMO

PEEK-OPTIMA™ polymer is being considered as an alternative material to cobalt chrome in the femoral component of total knee arthroplasty to give a metal-free knee replacement system. Simple geometry pin-on-plate wear simulation can be used to systematically investigate and understand the wear of materials under many different conditions. The aim of this study was to investigate the wear of UHMWPE-on-PEEK-OPTIMA™ under a range of contact pressure (2.1-80 MPa) and cross-shear ratio (0-0.18) conditions. With increasing contact pressure, there was a trend of decreasing UHMWPE wear factor with a significant difference (p<0.001) in the wear factor of UHMWPE under the different contact pressure conditions of interest. Under uniaxial motion (cross-shear ratio = 0), the wear of UHMWPE was low, introducing multi-axial motion increased the wear of the UHMWPE. There was a significant difference (p<0.01) in the wear factor at different cross-shear ratios however, post hoc analysis showed only the study carried out under unidirectional motion to be significantly different from the other conditions. With varying contact pressure and cross-shear ratio, the wear of UHMWPE against PEEK-OPTIMA™ polymer showed similar trends to previous studies of UHMWPE-on-cobalt chrome.


Assuntos
Artroplastia do Joelho , Humanos , Polietilenoglicóis , Cetonas , Teste de Materiais , Polietilenos , Polímeros , Cobalto , Falha de Prótese
18.
Int J Biol Macromol ; 253(Pt 8): 127636, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37884250

RESUMO

Levofloxacin (HLVX), a quinolone antimicrobial agent, when deprotonated (LVX-) behaves as a bidentate ligand, and it coordinates to Co2+ through the pyridone oxygen and the carboxylate oxygen. Along with two imidazole (ImH) ligands, levofloxacin forms a Co(II)-Levofloxacin-imidazole complex, [CoCl(LVX)(ImH)2(H2O)]·3H2O (abbreviated henceforth as CoLevim) which was isolated and characterized by 1H and 13C NMR spectroscopy, UV-visible and FT-IR spectroscopy, powder X-ray diffraction and thermal analysis methods. CoLevim shows promise in its antimicrobial activities when tested against microorganisms (Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Salmonella typhimurium and Escherichia coli). Fluorescence competitive studies with ethidium bromide (EB) revealed that CoLevim can compete with EB and displace it to bind to CT-DNA through intercalative binding mode. In addition, CoLevim exhibited a good binding propensity to BSA proteins with relatively high binding constants. The antioxidant activities of the free ligands and CoLevim were determined in vitro using ABTS+ radical (TEAC assay). The Co-complex showed a better antioxidant capacity with inhibitory concentrations (IC50) of 40 µM than the free ligands. CoLevim also showed noteworthy apoptotic potential and behaved as an efficient resistant modifying agent when its antiproliferative potential was examined by MTT assay using the breast cancer cell lines (MCF7, MCF7Dox/R and MCF7Pacli/R cells).


Assuntos
Anti-Infecciosos , Neoplasias da Mama , Complexos de Coordenação , Humanos , Feminino , Fluoroquinolonas/química , Levofloxacino/farmacologia , Cobalto/química , Antioxidantes , Neoplasias da Mama/tratamento farmacológico , Espectroscopia de Infravermelho com Transformada de Fourier , Complexos de Coordenação/química , DNA/química , Células MCF-7 , Etídio , Biopolímeros , Imidazóis/farmacologia , Oxigênio , Soroalbumina Bovina/química
19.
Proc Natl Acad Sci U S A ; 120(45): e2309156120, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37903261

RESUMO

Cobalt-containing alloys are useful for orthopedic applications due to their low volumetric wear rates, corrosion resistance, high mechanical strength, hardness, and fatigue resistance. Unfortunately, these prosthetics release significant levels of cobalt ions, which was only discovered after their widespread implantation into patients requiring hip replacements. These cobalt ions can result in local toxic effects-including peri-implant toxicity, aseptic loosening, and pseudotumor-as well as systemic toxic effects-including neurological, cardiovascular, and endocrine disorders. Failing metal-on-metal (MoM) implants usually necessitate painful, risky, and costly revision surgeries. To treat metallosis arising from failing MoM implants, a synovial fluid-mimicking chelator was designed to remove these metal ions. Hyaluronic acid (HA), the major chemical component of synovial fluid, was functionalized with British anti-Lewisite (BAL) to create a chelator (BAL-HA). BAL-HA effectively binds cobalt and rescues in vitro cell vitality (up to 370% of cells exposed to IC50 levels of cobalt) and enhances the rate of clearance of cobalt in vivo (t1/2 from 48 h to 6 h). A metallosis model was also created to investigate our therapy. Results demonstrate that BAL-HA chelator system is biocompatible and capable of capturing significant amounts of cobalt ions from the hip joint within 30 min, with no risk of kidney failure. This chelation therapy has the potential to mitigate cobalt toxicity from failing MoM implants through noninvasive injections into the joint.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Humanos , Prótese de Quadril/efeitos adversos , Ácido Hialurônico , Dimercaprol , Terapia por Quelação , Falha de Prótese , Artroplastia de Quadril/efeitos adversos , Metais , Cobalto , Quelantes/uso terapêutico , Íons
20.
Dalton Trans ; 52(45): 16754-16766, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37902558

RESUMO

tert-Butylhydroquinone (TBHQ) is a novel synthetic antioxidant with a higher safety profile and antioxidant effect that is more excellent than other synthetic antioxidants and is internationally recognized as one of the best food antioxidants. However, its excessive use in food can have unfavorable effects on the human body. Thus, it is critical to establish a rapid method for the detection of TBHQ in food samples. In this study, a cobalt-based metal-organic framework (Co-MOF) was fabricated by a one-pot hydrothermal method and embedded in multi-walled carbon nanotubes (MWCNTs) to construct an economical and sensitive electrochemical sensor for TBHQ. The results showed that this sensor possessed a wide linear range (0.004-20 µM and 20-300 µM), a low limit of detection (LOD = 2.5 nM, S/N = 3) as well as an ultra-high sensitivity (43.19 µA µM-1 cm-2). Moreover, the sensor also has superior selectivity, repeatability, reproducibility and anti-interference ability and can be successfully applied for the detection of TBHQ in samples of instant noodles and potato chips.


Assuntos
Estruturas Metalorgânicas , Nanotubos de Carbono , Humanos , Cobalto , Reprodutibilidade dos Testes , Antioxidantes , Eletrodos , Técnicas Eletroquímicas/métodos , Limite de Detecção
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