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1.
Artigo em Inglês | MEDLINE | ID: mdl-38839349

RESUMO

T-tubes and airway stents are commonly used but have limited effectiveness and frequent complications. A 50-year-old male patient presented with severe tracheal stenosis, affecting an 8.7 cm length of the airway. We employed an innovative approach known as external suspension fixation of tracheal stent using robotic assistance. This method involves surgically attaching the stent to the exterior of the trachea to provide support and stabilize the softened or collapsed tracheal segments. We designed a C-shaped nickel-titanium alloy exterior stent and successfully fixed it using robotic assistance. This intervention effectively restored tracheal function and led to a favorable postoperative recovery. The technique does not affect tracheal membrane function or airway mucociliary clearance. It could potentially be considered as a new option for treating long-segment benign tracheal softening or collapse.


Assuntos
Níquel , Desenho de Prótese , Procedimentos Cirúrgicos Robóticos , Stents , Titânio , Estenose Traqueal , Humanos , Masculino , Pessoa de Meia-Idade , Estenose Traqueal/cirurgia , Estenose Traqueal/diagnóstico por imagem , Estenose Traqueal/etiologia , Estenose Traqueal/fisiopatologia , Resultado do Tratamento , Ligas
2.
Sci Rep ; 14(1): 10556, 2024 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719847

RESUMO

Fertilization with nickel (Ni) can positively affect plant development due to the role of this micronutrient in nitrogen (N) metabolism, namely, through urease and NiFe-hydrogenase. Although the application of Ni is an emerging practice in modern agriculture, its effectiveness strongly depends on the chosen application method, making further research in this area essential. The individual and combined effects of different Ni application methods-seed treatment, leaf spraying and/or soil fertilization-were investigated in soybean plants under different edaphoclimatic conditions (field and greenhouse). Beneficial effects of the Soil, Soil + Leaf and Seed + Leaf treatments were observed, with gains of 7 to 20% in biological nitrogen fixation, 1.5-fold in ureides, 14% in shoot dry weight and yield increases of up to 1161 kg ha-1. All the Ni application methods resulted in a 1.1-fold increase in the SPAD index, a 1.2-fold increase in photosynthesis, a 1.4-fold increase in nitrogenase, and a 3.9-fold increase in urease activity. Edaphoclimatic conditions exerted a significant influence on the treatments. The integrated approaches, namely, leaf application in conjunction with soil or seed fertilization, were more effective for enhancing yield in soybean cultivation systems. The determination of the ideal method is crucial for ensuring optimal absorption and utilization of this micronutrient and thus a feasible and sustainable management technology. Further research is warranted to establish official guidelines for the application of Ni in agricultural practices.


Assuntos
Fertilizantes , Glycine max , Níquel , Solo , Glycine max/crescimento & desenvolvimento , Glycine max/efeitos dos fármacos , Glycine max/metabolismo , Fertilizantes/análise , Solo/química , Urease/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/efeitos dos fármacos , Fixação de Nitrogênio/efeitos dos fármacos , Nitrogênio/metabolismo , Fotossíntese/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/metabolismo , Agricultura/métodos
3.
PLoS One ; 19(5): e0302972, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38722925

RESUMO

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.


Assuntos
Hidrogênio , Níquel , Aço , Hidrogênio/química , Níquel/química , Aço/química , Fontes de Energia Elétrica , Propriedades de Superfície , Teste de Materiais
4.
Anal Chim Acta ; 1306: 342613, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38692794

RESUMO

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.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Géis , Glucose , Ouro , Níquel , Técnicas Biossensoriais/métodos , Níquel/química , Géis/química , Ouro/química , Glucose/análise , Eletrodos , Nanofios/química , Humanos , Limite de Detecção
5.
Sci Rep ; 14(1): 10032, 2024 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-38693156

RESUMO

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.


Assuntos
Cobalto , Complexos de Coordenação , Cobre , Isotiocianatos , Simulação de Acoplamento Molecular , Níquel , Níquel/química , Cobre/química , Humanos , Isotiocianatos/química , Isotiocianatos/farmacologia , Ligantes , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Cobalto/química , Linhagem Celular Tumoral , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química
6.
PLoS One ; 19(5): e0302551, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38696475

RESUMO

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.


Assuntos
Níquel , Propriedades de Superfície , Titânio , Titânio/química , Níquel/química , Microscopia de Força Atômica , Teste de Materiais , Preparo de Canal Radicular/instrumentação
7.
Clin Oral Investig ; 28(6): 338, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38797781

RESUMO

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.


Assuntos
Cefalometria , Incisivo , Má Oclusão , Desenho de Aparelho Ortodôntico , Braquetes Ortodônticos , Fios Ortodônticos , Humanos , Feminino , Masculino , Má Oclusão/terapia , Adolescente , Níquel/química , Arco Dental , Titânio/química , Resultado do Tratamento , Técnicas de Movimentação Dentária/instrumentação , Técnicas de Movimentação Dentária/métodos , Cobre
8.
Sci Rep ; 14(1): 11017, 2024 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-38745041

RESUMO

Mining activities have increased the potential risks of metal pollution to the groundwater resources in arid areas across the globe. Therefore, this study aimed to examine the health risk associated with nickel (Ni) in the groundwater sources of a mining-impacted area, South Khorasan, Eastern Iran. A total of 110 stations were included in the study, comprising 62 wells, 40 qanats, and 8 springs in summer, 2020. Initially, the collected samples were tested for temperature, pH, and electrical conductivity (EC). Subsequently, the samples were filtered and treated with nitric acid (HNO3) to measure the concentration of Ni using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Hazard quotient (HQ) and non-carcinogenic risk assessments were employed to evaluate the potential risks of Ni to the inhabitants. The findings revealed that the concentration of Ni ranged from 0.02 to 132.39 µg l-1, and only two stations exhibited Ni concentrations above the WHO standards (20 µg l-1). The results demonstrated that 98.21% of the sampled locations had HQ values below one, indicating negligible risk, while 1.78% of the stations exhibited HQ values of one or higher, representing a high non-carcinogenic risk for water consumers. Overall, the concentration of nickel in the groundwater of South Khorasan exceeded the World Health Organization (WHO) limit solely in the Halvan station, posing a non-carcinogenic risk for the residents in that area, and therefore, additional efforts should be made to provide healthier groundwater to consumers in this region.


Assuntos
Monitoramento Ambiental , Água Subterrânea , Mineração , Níquel , Poluentes Químicos da Água , Níquel/análise , Água Subterrânea/análise , Água Subterrânea/química , Medição de Risco , Poluentes Químicos da Água/análise , Humanos , Irã (Geográfico) , Monitoramento Ambiental/métodos
9.
Sci Rep ; 14(1): 11042, 2024 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-38745058

RESUMO

Nickel (Ni) is a heavy metal that adversely affects the growth of different crops by inducing oxidative stress and nutrient imbalance. The role of rhizobacteria (RB) is vital to resolve this issue. They can promote root growth and facilitate the uptake of water and nutrients, resulting in better crop growth. On the other hand, γ-aminobutyric acid (GABA) can maintain the osmotic balance and scavenge the reactive oxygen species under stress conditions. However, the combined effect of GABA and RB has not been thoroughly explored to alleviate Ni toxicity, especially in fenugreek plants. Therefore, in the current pot study, four treatments, i.e., control, A. fabrum (RB), 0.40 mM GABA, and 0.40 mM GABA + RB, were applied under 0Ni and 80 mg Ni/kg soil (80Ni) stress. Results showed that RB + 0.40 mM GABA caused significant improvements in shoot length (~ 13%), shoot fresh weight (~ 47%), shoot dry weight (~ 47%), root length (~ 13%), root fresh weight (~ 60%), and root dry weight (~ 15%) over control under 80 Ni toxicity. A significant enhancement in total chlorophyll (~ 14%), photosynthetic rate (~ 17%), stomatal CO2 concentration (~ 19%), leaves and roots N (~ 10 and ~ 37%), P (~ 18 and ~ 7%) and K (~ 11 and ~ 30%) concentrations, while a decrease in Ni (~ 83 and ~ 49%) concentration also confirmed the effectiveness of RB + 0.40 mM GABA than control under 80Ni. In conclusion, fabrum + 0.40 mM GABA can potentially alleviate the Ni toxicity in fenugreek plants. The implications of these findings extend to agricultural practices, environmental remediation efforts, nutritional security, and ecological impact. Further research is recommended to elucidate the underlying mechanisms, assess long-term effects, and determine the practical feasibility of using A. fabrum + 0.40GABA to improve growth in different crops under Ni toxicity.


Assuntos
Níquel , Trigonella , Ácido gama-Aminobutírico , Níquel/toxicidade , Ácido gama-Aminobutírico/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Poluentes do Solo/toxicidade
10.
BMC Oral Health ; 24(1): 564, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38745154

RESUMO

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.


Assuntos
Ligas , Clorexidina , Ligas Dentárias , Microscopia Eletrônica de Varredura , Níquel , Fios Ortodônticos , Fluoreto de Sódio , Propriedades de Superfície , Humanos , Fluoreto de Sódio/uso terapêutico , Clorexidina/uso terapêutico , Corrosão , Ligas Dentárias/química , Níquel/química , Titânio/química , Cariostáticos/uso terapêutico , Cariostáticos/química , Masculino , Feminino , Adulto Jovem , Antissépticos Bucais/uso terapêutico , Antissépticos Bucais/química , Processamento de Imagem Assistida por Computador/métodos , Adolescente , Adulto , Higiene Bucal
11.
Plant Physiol Biochem ; 211: 108711, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38733941

RESUMO

Trace heavy metals (HMs) such as copper (Cu) and nickel (Ni) are toxic to plants, especially tomato at high levels. In this study, biochar (BC) was treated with amino acids (AA) to enhance amino functional groups, which effectively alleviated the adverse effects of heavy metals (HMs) on tomato growth. Hence, this study aimed to evaluate the effect of glycine and alanine modified BC (GBC/ABC) on various tomato growth parameters, its physiology, fruit yield and Cu/Ni uptake under Cu and Ni stresses. In a pot experiment, there was 21 treatments with three replications having two rates of simple BC and glycine/alanine enriched BC (0.5% and 1% (w/w). Cu and Ni stresses were added at 150 mg kg-1 respectively. Plants were harvested after 120 days of sowing and subjected to various analysis. Under Cu and Ni stresses, tomato roots accumulated more Cu and Ni than shoots and fruits, while GBC and ABC application significantly enhanced the root and shoot dry weight irrelevant to the stress conditions. Both rates of GBC decreased the malondialdehyde and hydrogen peroxide levels in plants. The addition of 0.5% GBC with Cu enhanced the tomato fruit dry weight by 1.3 folds in comparison to the control treatment; while tomato fruit juice content also increased (50%) in the presence of 0.5% GBC with Ni as compared to control. In summary, these results demonstrated that lower rate of GBC∼0.5% proved to be the best in mitigating the Cu and Ni stress on tomato plant growth by enhancing the fruit production.


Assuntos
Aminoácidos , Carvão Vegetal , Cobre , Frutas , Níquel , Solanum lycopersicum , Solanum lycopersicum/efeitos dos fármacos , Solanum lycopersicum/crescimento & desenvolvimento , Solanum lycopersicum/metabolismo , Níquel/farmacologia , Frutas/efeitos dos fármacos , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Carvão Vegetal/farmacologia , Aminoácidos/metabolismo , Poluentes do Solo , Estresse Fisiológico/efeitos dos fármacos , Solo/química
12.
Biosensors (Basel) ; 14(5)2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38785712

RESUMO

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.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Nanoestruturas , Humanos , Óxidos/química , Níquel/química , Titânio/química , Óxido de Zinco/química , Metais/química , Cobre/análise , Cobre/química
13.
ACS Sens ; 9(5): 2395-2401, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38722860

RESUMO

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.


Assuntos
Hidrogênio , Níquel , Oxirredução , Paládio , Som , Hidrogênio/química , Paládio/química , Níquel/química , Propriedades de Superfície , Teoria da Densidade Funcional , Espectroscopia Fotoeletrônica , Ligas/química
14.
Bioelectrochemistry ; 158: 108728, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38733721

RESUMO

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.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Técnicas Eletroquímicas , Grafite , Limite de Detecção , Nanopartículas Metálicas , Paládio , Platina , Prata , Grafite/química , Aptâmeros de Nucleotídeos/química , Técnicas Eletroquímicas/métodos , Platina/química , Técnicas Biossensoriais/métodos , Nanopartículas Metálicas/química , Paládio/química , Prata/química , Níquel/química , Polietilenoimina/química , Cobalto/química , Reprodutibilidade dos Testes
15.
Molecules ; 29(10)2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38792033

RESUMO

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.


Assuntos
Complexos de Coordenação , Cobre , Níquel , Fragmentos de Peptídeos , Zinco , Proteínas tau , Níquel/química , Cobre/química , Zinco/química , Proteínas tau/química , Complexos de Coordenação/química , Fragmentos de Peptídeos/química , Oxirredução , Histidina/química , Concentração de Íons de Hidrogênio , Peróxido de Hidrogênio/química , Termodinâmica
16.
Food Chem ; 452: 139575, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38735112

RESUMO

Dimetridazole (DMZ) is a broad-spectrum antibiotic effective against bacterial and protozoan infections in humans and poultry farms. However, excessive DMZ intake leads to harmful effects. Thus, minimizing its environmental presence is crucial for sustaining daily life. This study presents an innovative approach to construct flower-like SnS particle decorations on a nickel metal-organic framework (Ni-MOF@SnS) as an electrocatalyst for DMZ detection. The Ni-MOF@SnS/GCE sensor exhibits exceptional electrocatalytic behavior, including a significantly reduced detection limit of 1.6 nM, extensive linear ranges from 0.01 µM to 60 µM and from 60 µM to 231 µM at lower and higher DMZ concentrations, respectively. It also shows enhanced sensitivity (0.139 µA µM-1 cm-2) and remarkable selectivity for DMZ detection using differential-pulse voltammetry (DPV). Furthermore, the proposed sensor demonstrates good recovery results with actual food samples.


Assuntos
Técnicas Eletroquímicas , Contaminação de Alimentos , Estruturas Metalorgânicas , Níquel , Níquel/química , Níquel/análise , Técnicas Eletroquímicas/instrumentação , Estruturas Metalorgânicas/química , Contaminação de Alimentos/análise , Limite de Detecção , Animais , Antibacterianos/análise , Antibacterianos/farmacologia
17.
Nat Commun ; 15(1): 4036, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38740750

RESUMO

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.


Assuntos
Proteínas de Bactérias , Níquel , Níquel/metabolismo , Níquel/química , Animais , Virulência/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Biofilmes/efeitos dos fármacos , Zinco/metabolismo , Zinco/química , Mariposas/microbiologia , Urease/metabolismo , Urease/antagonistas & inibidores , Transporte Biológico
18.
BMC Oral Health ; 24(1): 558, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38741081

RESUMO

BACKGROUND: We investigated the efficacy of two different cold atmospheric pressure jet plasma devices (CAP09 and CAPmed) and an air polishing device with glycine powder (AP) either applied as monotherapies or combined therapies (AP + CAP09; AP + CAPmed), in microbial biofilm removal from discs with anodised titanium surface. METHODS: Discs covered with 7-day-old microbial biofilm were treated either with CAP09, CAPmed, AP, AP + CAP09 or AP + CAPmed and compared with negative and positive controls. Biofilm removal was assessed with flourescence and electron microscopy immediately after treatment and after 5 days of reincubation of the treated discs. RESULTS: Treatment with CAP09 or CAPmed did not lead to an effective biofilm removal, whereas treatment with AP detached the complete biofilm, which however regrew to baseline magnitude after 5 days of reincubation. Both combination therapies (AP + CAP09 and AP + CAPmed) achieved a complete biofilm removal immediately after cleaning. However, biofilm regrew after 5 days on 50% of the discs treated with the combination therapy. CONCLUSION: AP treatment alone can remove gross biofilm immediately from anodised titanium surfaces. However, it did not impede regrowth after 5 days, because microorganisms were probably hidden in holes and troughs, from which they could regrow, and which were inaccessible to AP. The combination of AP and plasma treatment probably removed or inactivated microorganisms also from these hard to access spots. These results were independent of the choice of plasma device.


Assuntos
Biofilmes , Implantes Dentários , Gases em Plasma , Propriedades de Superfície , Titânio , Biofilmes/efeitos dos fármacos , Titânio/química , Implantes Dentários/microbiologia , Polimento Dentário/métodos , Glicina , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Níquel
19.
Luminescence ; 39(5): e4768, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38719590

RESUMO

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.


Assuntos
Cobalto , Eletroquímica , Eletrodos , Nanocompostos , Níquel , Nanocompostos/química , Níquel/química , Cobalto/química , Difração de Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Luminescência , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Fenômenos Magnéticos , Nanopartículas/química , Luz , Catálise , Óxidos/química , Azul de Metileno/metabolismo
20.
Clin Exp Dent Res ; 10(3): e893, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38770579

RESUMO

OBJECTIVES: The present study reviews the current literature regarding the utilization of the extended finite element method (XFEM) in clinical and experimental endodontic studies and the suitability of XFEM in the assessment of cyclic fatigue in rotary endodontic nickel-titanium (NiTi) instruments. MATERIAL AND METHODS: An electronic literature search was conducted using the appropriate search terms, and the titles and abstracts were screened for relevance. The search yielded 13 hits after duplicates were removed, and four studies met the inclusion criteria for review. RESULTS: No studies to date have utilized XFEM to study cyclic fatigue or crack propagation in rotary endodontic NiTi instruments. Challenges such as modelling material inputs and fatigue criteria could explain the lack of utilization of XFEM in the analysis of mechanical behavior in NiTi instruments. CONCLUSIONS: The review showed that XFEM was seldom employed in endodontic literature. Recent work suggests potential promise in using XFEM for modelling NiTi structures.


Assuntos
Endodontia , Análise de Elementos Finitos , Níquel , Titânio , Humanos , Ligas Dentárias/química , Instrumentos Odontológicos , Endodontia/instrumentação , Endodontia/métodos , Teste de Materiais , Preparo de Canal Radicular/instrumentação , Preparo de Canal Radicular/métodos , Estresse Mecânico
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