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1.
Methods Mol Biol ; 2835: 307-315, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39105926

RESUMO

Cell therapy and engineered tissue creation based on the use of human stem cells involves cell isolation, expansion, and cell growth and differentiation on the scaffolds. Microbial infections dramatically can affect stem cell survival and increase the risk of implant failure. To prevent these events, it is necessary to develop new materials with antibacterial properties for coating scaffold surfaces as well as medical devices, and all other surfaces at high risk of contamination. This chapter describes strategies for obtaining antibacterial blends for coating inert surfaces (polymethylmethacrylate, polycarbonate, Carbon Fiber Reinforced Polymer (CFRP)). In particular, the procedures for preparing antibacterial blends by mixing polymer resins with two types of antibacterial additives and depositing these blends on inert surfaces are described.


Assuntos
Células-Tronco , Engenharia Tecidual , Humanos , Engenharia Tecidual/métodos , Células-Tronco/citologia , Propriedades de Superfície , Alicerces Teciduais/química , Antibacterianos/farmacologia , Cimento de Policarboxilato/química , Técnicas de Cultura de Células/métodos , Polimetil Metacrilato/química , Fibra de Carbono/química , Carbono/química , Anti-Infecciosos/farmacologia
2.
Int J Mol Sci ; 25(15)2024 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-39126084

RESUMO

Nowadays, owing to the new technological and industrial requirements for equipment, such as flexibility or multifunctionally, the development of all-solid-state supercapacitors and Li-ion batteries has become a goal for researchers. For these purposes, the composite material approach has been widely proposed due to the promising features of woven carbon fiber as a substrate material for this type of material. Carbon fiber displays excellent mechanical properties, flexibility, and high electrical conductivity, allowing it to act as a substrate and a collector at the same time. However, carbon fiber's energy-storage capability is limited. Several coatings have been proposed for this, with nanostructured transition metal oxides being one of the most popular due to their high theoretical capacity and surface area. In this overview, the main techniques used to achieve these coatings-such as solvothermal synthesis, MOF-derived obtention, and electrochemical deposition-are summarized, as well as the main strategies for alleviating the low electrical conductivity of transition metal oxides, which is the main drawback of these materials.


Assuntos
Fibra de Carbono , Capacitância Elétrica , Fontes de Energia Elétrica , Eletrodos , Lítio , Nanoestruturas , Óxidos , Lítio/química , Fibra de Carbono/química , Óxidos/química , Nanoestruturas/química , Elementos de Transição/química , Condutividade Elétrica , Metais/química
3.
J Biomed Mater Res B Appl Biomater ; 112(9): e35467, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39180195

RESUMO

The objective of the present study was to evaluate the carbon fiber obtained from textile PAN fiber, in its different forms, as a potential scaffolds synthetic bone. Thirty-four adult rats were used (Rattus norvegicus, albinus variation), two critical sized bone defects were made that were 5 mm in diameter. Twenty-four animals were randomly divided into four groups: control (C)-bone defect + blood clot, non-activated carbon fiber felt (NACFF)-bone defect + NACFF, activated carbon fiber felt (ACFF)-bone defect + ACFF, and silver activated carbon fiber felt (Ag-ACFF)-bone defect + Ag-ACFF, and was observed by 15 and 60 days for histomorphometric, three-dimensional computerized microtomography (microCT) and mineral apposition analysis. On histomorphometric and microCT analyses, NACFF were associated with higher proportion of neoformed bone and maintenance of bone structure. On fluorochrome bone label, there was no differences between the groups. NACFF has shown to be a promising synthetic material as a scaffold for bone regeneration.


Assuntos
Regeneração Óssea , Fibra de Carbono , Carbono , Alicerces Teciduais , Microtomografia por Raio-X , Animais , Ratos , Regeneração Óssea/efeitos dos fármacos , Alicerces Teciduais/química , Carbono/química , Fibra de Carbono/química , Masculino , Têxteis , Brasil , Teste de Materiais , Ratos Wistar
4.
Jt Dis Relat Surg ; 35(3): 483-490, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-39189556

RESUMO

OBJECTIVES: The aim of the present meta-analysis was to compare the efficacy and safety of the carbon fiber-reinforced polyetheretherketone (CFR-PEEK) and titanium plate for the treatment of proximal humeral fractures (PHFs) from clinical comparative trials. MATERIALS AND METHODS: A comprehensive search of English databases was carried out, such as PubMed, Web of Science, ScienceDirect, Springer and Cochrane Library databases. The RevMan version 5.1 software was applied for statistical analysis, and the mean difference (MD) and risk difference (RD) as the combined variables, and "95%" as the confidence interval (CIs). RESULTS: One randomized-controlled trial and five retrospective controlled studies including 282 PHFs were considered eligible and finally included. Meta-analysis demonstrated that there were significant differences in Constant score (CS) (MD=9.23; 95% CI: 5.02, 13.44; p<0.0001), anterior elevation (MD=18.83; 95% CI: 6.27, 31.38; p=0.003), lateral elevation (MD=18.42; 95% CI: 3.64, 33.19; p=0.01) and adduction (MD=3.53; 95% CI: 0.22, 6.84; p=0.04). No significant differences were observed regarding Constant score compared to the contralateral shoulder, Oxford Shoulder Score, internal rotation, external rotation, screw perforation and cutout, varus/valgus malalignment, humeral head collapse/necrosis, implant removal, and revision surgery between the two groups. CONCLUSION: Compared to titanium plate, CFR-PEEK plate showed better Constant score, anterior elevation, lateral elevation and adduction in treating PHFs. The complications are comparable to those achieved with conventional titanium plates.


Assuntos
Benzofenonas , Placas Ósseas , Fibra de Carbono , Fixação Interna de Fraturas , Cetonas , Polietilenoglicóis , Polímeros , Fraturas do Ombro , Titânio , Humanos , Fraturas do Ombro/cirurgia , Fixação Interna de Fraturas/métodos , Fixação Interna de Fraturas/instrumentação , Resultado do Tratamento , Carbono
5.
J Biomed Mater Res B Appl Biomater ; 112(8): e35463, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39115314

RESUMO

Secondary healing of fractured bones requires an application of an appropriate fixator. In general, steel or titanium devices are used mostly. However, in recent years, composite structures arise as an attractive alternative due to high strength to weight ratio and other advantages like, for example, radiolucency. According to Food and Drug Administration (FDA), the only unidirectionally reinforced composite allowed to be implanted in human bodies is carbon fiber (CF)-reinforced poly-ether-ether-ketone (PEEK). In this work, the healing process of long bone assembled with CF/PEEK plates with cross- and angle-ply lay-up configurations is studied in the framework of finite element method. The healing is simulated by making use of the mechanoregulation model basing on the Prendergast theory. Cells transformation is determined by the octahedral shear strain and interstitial fluid velocity. The process runs iteratively assuming single load cycle each day. The fracture is subjected to axial and transverse forces. In the computations, the Abaqus program is used. It is shown that the angle-ply lamination scheme of CF/PEEK composite seems to provide better conditions for the transformation of the soft callus into the bone tissue.


Assuntos
Benzofenonas , Placas Ósseas , Fibra de Carbono , Consolidação da Fratura , Cetonas , Polietilenoglicóis , Polímeros , Cetonas/química , Fibra de Carbono/química , Polietilenoglicóis/química , Polímeros/química , Humanos , Carbono/química , Fraturas Ósseas , Análise de Elementos Finitos
6.
ACS Appl Bio Mater ; 7(8): 5397-5410, 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39051842

RESUMO

Photocatalytic antimicrobials, as emerging advanced oxidative antimicrobial materials, have the advantages of low price and long-lasting antimicrobial properties. Nevertheless, with catalysts increasingly trending toward nanoscale dimensions, the environmental challenge of catalyst recycling becomes more pronounced. In this paper, we propose utilizing one-dimensional carbon fiber as a substrate, employing the nucleating agent method to induce Titanium dioxide (TiO2) growth on the fiber surface. Furthermore, the material's band gap underwent modification through hydrogen calcination, thus resulting in the attainment of hierarchical black TiO2/carbon fiber composites with visible light-driven capabilities. The characterization of the materials was conducted via scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The results revealed that when the black hydrogenated TiO2 was composited with carbon fiber, the Schottky heterojunction was formed, and thus effectively improved the photocatalytic effect of the composites. Notably, the degradation rate of methylene blue achieved 96.25% within 150 min when utilizing black TiO2/carbon fiber composites, while the inactivation rate of Escherichia coli (E. coli) reached 97.58% within 0.5 h and attained complete inactivation within 60 min.


Assuntos
Fibra de Carbono , Escherichia coli , Teste de Materiais , Tamanho da Partícula , Titânio , Titânio/química , Escherichia coli/efeitos dos fármacos , Catálise , Fibra de Carbono/química , Processos Fotoquímicos , Luz , Propriedades de Superfície , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/síntese química , Carbono/química , Azul de Metileno/química
7.
Int J Biol Macromol ; 276(Pt 1): 133877, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39009255

RESUMO

The adhesive strength between the sizing agent and carbon fiber (CF) plays a crucial role in improving the interfacial properties of composites, while such a vital aspect has been consistently disregarded. In this study, a hyperbranched waterborne polyurethane (HWPU) sizing agent was synthesized from biogenetically raw materials including gallic acid, l-Lysine diisocyanate and amylopectin. Concurrently, hydrogen-bonded cross-linked network structures were established utilizing a botanical polyphenol tannin as coupling agent to effectively connect CF with HWPU. This meticulous process yielded CF/nylon 6 composites with improved properties and their mechanical characteristics were systematically investigated. The findings showcased a noteworthy boost in flexural strength and interlaminar shear strength (ILSS), showing enhancements of 54.6 % and 61.4 %, respectively, surpassing those of untreated CF. Furthermore, the interfacial shear strength (IFSS) test indicated a remarkable 70.3 % improvement. This approach presents a highly promising concept aimed at developing sustainable green waterborne polyurethane sizing agent and improving the interfacial performance of CF composite materials.


Assuntos
Amilopectina , Fibra de Carbono , Ligação de Hidrogênio , Polifenóis , Poliuretanos , Poliuretanos/química , Polifenóis/química , Fibra de Carbono/química , Amilopectina/química , Água/química , Resistência ao Cisalhamento
8.
Waste Manag ; 187: 134-144, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39032436

RESUMO

Here we report a novel chemical recycling of carbon fiber-reinforced plastic (CFRP) using meta-chloroperoxybenzoic acid (mCPBA) as the representative oxidizing agent. The optimal decomposition conditions for the epoxy (EP) resin in CFRP were investigated by varying mCPBA concentration and reaction time. The CFRP decomposed completely within 6 h using a 1.5 M mCPBA solution at 40 °C. Tensile strength of recovered CF (r-CF) measured 4.4 GPa, 93.6% of virgin CF (v-CF), and electrical conductivity reached 590 S/cm, 95% of v-CF. Furthermore, the interfacial shear strength (IFSS) of the recovered carbon fibers (r-CF) using EP resin and polyamide 6 (PA6) was analyzed. For EP resin, the IFSS of r-CF was 88 MPa, a 26 % increase compared to v-CF. In the case of PA6 resin, IFSS values were 80 MPa for r-CF, a 17% improvement over v-CF. The study highlights superior mechanical properties and favorable IFSS of r-CF, positioning them as promising for composite regeneration. Remarkably, this method operated at relatively low temperatures compared to existing technologies, with energy consumption recorded at 35 MJ/kg, establishing it as the most energy-efficient recycling method available.


Assuntos
Fibra de Carbono , Reciclagem , Resistência ao Cisalhamento , Fibra de Carbono/química , Reciclagem/métodos , Plásticos/química , Resinas Epóxi/química , Resistência à Tração , Carbono/química , Caprolactama/análogos & derivados , Polímeros
9.
Int J Biol Macromol ; 275(Pt 1): 133568, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38969033

RESUMO

This paper initially examines the feasibility and effectiveness on interfacial adhesion of composites when grafting nanoparticle-structured polydopamine (PDA) and chitosan around carbon fiber periphery. The resulting interfacial shear strength was maximized as 92.3 MPa, delivering 50.1 % and 15.7-16.2 % gains over those of control fiber and only polydopamine nanospheres (PDANPs) or only chitosan modified fiber composites. Measuring surface morphology and thermal stability of fibers found that abundant PDANPs well adhered with the help of chitosan, highlighting nanoscale size effects and intrinsic adhesiveness of PDA. Under good wettability, rich and dense interfacial interactions (covalent and hydrogen bond, electrostatic interaction, and π conjugation) caused by PDANPs/chitosan coating provides impetus for effective stress transfer. Additionally, the stable "soft-rigid" combination of chitosan and PDANPs adds the efficiency of crack passivation. As such, it is hoped that this work could fully explore the possibility of PDA geometry in interphase engineering of fiber composites.


Assuntos
Fibra de Carbono , Quitosana , Indóis , Nanosferas , Polímeros , Quitosana/química , Indóis/química , Nanosferas/química , Polímeros/química , Fibra de Carbono/química , Molhabilidade
10.
Food Chem ; 459: 140378, 2024 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38991446

RESUMO

In this study, a hydrothermal process was utilized to grow mixed-valence CuFe2O4/Cu0 nanosheets on carbon fiber paper, forming a three-dimensional hierarchical electrode (CuFe2O4/Cu0@CFP). The ordered array structure, coupled with the porous bowl-like structure, enhances the exposure of more electrode active sites and facilitates analyte penetration, thus enhancing the electrode sensing performance. As a binder-free sensor, the CuFe2O4/Cu0@CFP sensor exhibited remarkable sensitivity in detecting Malachite Green (MG), Sunset Yellow (SY) and Tartrazine (TA) over wide concentration ranges: 0.1-300 µM for MG (R2 = 0.994), 0.005-200 µM for SY (R2 = 0.996), and 0.005-300 µM for TA (R2 = 0.995) with low detection limits of 0.033 µM for MG, 0.0016 µM for SY, and 0.0016 µM for TA (S/N = 3), respectively. Additionally, the 3D CuFe2O4/Cu0@CFP sensor detected MG, SY, and TA in a mixed solution with satisfactory results. It also performs well in beverage, fruit juice powder, and jelly samples, with results matching those from HPLC.


Assuntos
Compostos Azo , Cobre , Nanoestruturas , Corantes de Rosanilina , Tartrazina , Cobre/química , Cobre/análise , Tartrazina/análise , Tartrazina/química , Nanoestruturas/química , Corantes de Rosanilina/química , Corantes de Rosanilina/análise , Compostos Azo/química , Compostos Azo/análise , Fibra de Carbono/química , Contaminação de Alimentos/análise , Técnicas Eletroquímicas/instrumentação , Limite de Detecção , Corantes de Alimentos/análise , Corantes de Alimentos/química , Papel
11.
Biomed Mater Eng ; 35(4): 401-414, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38995767

RESUMO

BACKGROUND: The prosthetic foot is an essential component of the prosthetic limb used by people who suffer from amputation. The prosthetic foot or limb is expensive in developing countries and cannot be used by most people with special needs. OBJECTIVE: In this study, an uncomplicated prosthetic foot is designed that can be manufactured at low costs using 3D printer technology and can be provided to a wide range of amputees. The foot was designed using CAD software and analyzed using ANSES. METHODS: Carbon fiber material was chosen to be suitable for the manufacturing process using 3D printer technology. The selected material was tested in tensile and fatigue tests to determine its mechanical properties. The numerical analysis was carried out assuming the use of an artificial foot by a patient weighing 85 kg. RESULTS: The results showed that the material proposed for manufacturing has good mechanical properties for this application. The results of the engineering analysis also showed that the model has successfully passed the design process and is reliable for use by amputees. CONCLUSION: The success model designed in this study in the numerical analysis process gives reliability to the use of this design to manufacture the prosthetic foot.


Assuntos
Membros Artificiais , Simulação por Computador , , Impressão Tridimensional , Desenho de Prótese , Humanos , Resistência à Tração , Desenho Assistido por Computador , Amputados/reabilitação , Fibra de Carbono/química , Teste de Materiais , Análise de Elementos Finitos , Estresse Mecânico
12.
Biosensors (Basel) ; 14(7)2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39056628

RESUMO

Fast-scan cyclic voltammetry (FSCV) is an electrochemical sensing technique that can be used for neurochemical sensing with high spatiotemporal resolution. Carbon fiber microelectrodes (CFMEs) are traditionally used as FSCV sensors. However, CFMEs are prone to electrochemical fouling caused by oxidative byproducts of repeated serotonin (5-HT) exposure, which makes them less suitable as chronic 5-HT sensors. Our team is developing a boron-doped diamond microelectrode (BDDME) that has previously been shown to be relatively resistant to fouling caused by protein adsorption (biofouling). We sought to determine if this BDDME exhibits resistance to electrochemical fouling, which we explored on electrodes fabricated with either femtosecond laser cutting or physical cleaving. We recorded the oxidation current response after 25 repeated injections of 5-HT in a flow-injection cell and compared the current drop from the first with the last injection. The 5-HT responses were compared with dopamine (DA), a neurochemical that is known to produce minimal fouling oxidative byproducts and has a stable repeated response. Physical cleaving of the BDDME yielded a reduction in fouling due to 5-HT compared with the CFME and the femtosecond laser cut BDDME. However, the femtosecond laser cut BDDME exhibited a large increase in sensitivity over the cleaved BDDME. An extended stability analysis was conducted for all device types following 5-HT fouling tests. This analysis demonstrated an improvement in the long-term stability of boron-doped diamond over CFMEs, as well as a diminishing sensitivity of the laser-cut BDDME over time. This work reports the electrochemical fouling performance of the BDDME when it is repeatedly exposed to DA or 5-HT, which informs the development of a chronic, diamond-based electrochemical sensor for long-term neurotransmitter measurements in vivo.


Assuntos
Boro , Diamante , Técnicas Eletroquímicas , Microeletrodos , Serotonina , Serotonina/análise , Boro/química , Diamante/química , Técnicas Biossensoriais , Dopamina/análise , Fibra de Carbono , Oxirredução
13.
Anal Bioanal Chem ; 416(21): 4807-4818, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38914733

RESUMO

The hormone Neuropeptide Y (NPY) plays critical roles in feeding, satiety, obesity, and weight control. However, its complex peptide structure has hindered the development of fast and biocompatible detection methods. Previous studies utilizing electrochemical techniques with carbon fiber microelectrodes (CFMEs) have targeted the oxidation of amino acid residues like tyrosine to measure peptides. Here, we employ the modified sawhorse waveform (MSW) to enable voltammetric identification of NPY through tyrosine oxidation. Use of MSW improves NPY detection sensitivity and selectivity by reducing interference from catecholamines like dopamine, serotonin, and others compared to the traditional triangle waveform. The technique utilizes a holding potential of -0.2 V and a switching potential of 1.2 V that effectively etches and renews the CFME surface to simultaneously detect NPY and other monoamines with a sensitivity of 5.8 ± 0.94 nA/µM (n = 5). Furthermore, we observed adsorption-controlled, subsecond NPY measurements with CFMEs and MSW. The effective identification of exogenously applied NPY in biological fluids demonstrates the feasibility of this methodology for in vivo and ex vivo studies. These results highlight the potential of MSW voltammetry to enable fast, biocompatible NPY quantification to further elucidate its physiological roles.


Assuntos
Técnicas Eletroquímicas , Neuropeptídeo Y , Neuropeptídeo Y/análise , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Microeletrodos , Humanos , Oxirredução , Fibra de Carbono/química , Tirosina/análise , Tirosina/química , Animais
14.
Angew Chem Int Ed Engl ; 63(36): e202407063, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-38898543

RESUMO

Developing real-time, dynamic, and in situ analytical methods with high spatial and temporal resolutions is crucial for exploring biochemical processes in the brain. Although in vivo electrochemical methods based on carbon fiber (CF) microelectrodes are effective in monitoring neurochemical dynamics during physiological and pathological processes, complex post modification hinders large-scale productions and widespread neuroscience applications. Herein, we develop a general strategy for the in situ engineering of carbon-based materials to mass-produce functional CFs by introducing polydopamine to anchor zeolitic imidazolate frameworks as precursors, followed by one-step pyrolysis. This strategy demonstrates exceptional universality and design flexibility, overcoming complex post-modification procedures and avoiding the delamination of the modification layer. This simplifies the fabrication and integration of functional CF-based microelectrodes. Moreover, we design highly stable and selective H+, O2, and ascorbate microsensors and monitor the influence of CO2 exposure on the O2 content of the cerebral tissue during physiological and ischemia-reperfusion pathological processes.


Assuntos
Fibra de Carbono , Carbono , Fibra de Carbono/química , Carbono/química , Técnicas Eletroquímicas/métodos , Polímeros/química , Animais , Indóis/química , Microeletrodos , Ácido Ascórbico/química , Oxigênio/química , Oxigênio/metabolismo , Zeolitas/química , Imidazóis/química , Dióxido de Carbono/química
15.
PLoS One ; 19(6): e0303293, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38865365

RESUMO

Silica aerogels or xerogels are renowned dried gels with low density, high surface area, higher porosity, and better thermal stability which makes it suitable for aerospace, light weight structures, thermal insulation, and hydrophobic coatings. But brittle behaviour, low mechanical strength, and high manufacturing cost restrict its usage. Recently, the addition of various fibres like glass or carbon fiber is one of the best reinforcement methods to minimize the brittle behaviour. Supercritical drying technique usually used to develop aerogel that is expensive and difficult to produce in bulk quantities. Higher cost obstacle can be tackled by applying ambient pressure drying technique to develop xerogel. But researcher observed cracks in samples prepared through the ambient pressure drying technique is still a major shortcoming. The aim of this study is to systematically analyze the influence of silica gel fiber reinforcement on silica xerogels, encompassing morphology, mechanics, thermal behaviour, compression test, and thermogravimetric characteristics. The research used a low-cost precursor named Tetraethyl orthosilicate to synthesize low-cost composite Silica xerogel and glass and carbon fiber added to provide strength and flexibility to the overall composite. Silica gel works as binder in strengthening the xerogel network. The investigation employs scanning electron microscopy (SEM) to examine the morphology of the composites, Fourier Transform Infrared (FTIR) analysis to affirm hydrophobic characteristics, compression tests to assess mechanical strength, and thermogravimetric tests to study weight loss under different conditions. SEM results reveals that glass fibers exhibit lower adhesion to the xerogel network compared to carbon fibers. FTIR analysis confirms the hydrophobicity of the composite silica xerogel. Compression tests showed that, under a 48% strain rate, the carbon fiber composite demonstrates superior compressive stress endurance. Thermogravimetric tests revealed a 1% lower weight loss for the carbon fiber composite compared to the glass fiber composite. This work concludes that glass and carbon fiber together with silica gel particles successfully facilitated in developing flexible, less costly, hydrophobic, and crack-free silica xerogel composites by APD. These advancements have the potential to drive innovations in material science and technology across diverse industries.


Assuntos
Dióxido de Silício , Dióxido de Silício/química , Termogravimetria , Géis/química , Sílica Gel/química , Vidro/química , Temperatura , Fibra de Carbono/química , Microscopia Eletrônica de Varredura , Porosidade , Teste de Materiais , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Sci Rep ; 14(1): 13215, 2024 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-38851842

RESUMO

Using a curved carbon-fiber plate (CFP) in running shoes may offer notable performance benefit over flat plates, yet there is a lack of research exploring the influence of CFP geometry on internal foot loading during running. The objective of this study was to investigate the effects of CFP mechanical characteristics on forefoot biomechanics in terms of plantar pressure, bone stress distribution, and contact force transmission during a simulated impact peak moment in forefoot strike running. We employed a finite element model of the foot-shoe system, wherein various CFP configurations, including three stiffnesses (stiff, stiffer, and stiffest) and two shapes (flat plate (FCFP) and curved plate (CCFP)), were integrated into the shoe sole. Comparing the shoes with no CFP (NCFP) to those with CFP, we consistently observed a reduction in peak forefoot plantar pressure with increasing CFP stiffness. This decrease in pressure was even more notable in a CCFP demonstrating a further reduction in peak pressure ranging from 5.51 to 12.62%, compared to FCFP models. Both FCFP and CCFP designs had a negligible impact on reducing the maximum stress experienced by the 2nd and 3rd metatarsals. However, they greatly influenced the stress distribution in other metatarsal bones. These CFP designs seem to optimize the load transfer pathway, enabling a more uniform force transmission by mainly reducing contact force on the medial columns (the first three rays, measuring 0.333 times body weight for FCFP and 0.335 for CCFP in stiffest condition, compared to 0.373 in NCFP). We concluded that employing a curved CFP in running shoes could be more beneficial from an injury prevention perspective by inducing less peak pressure under the metatarsal heads while not worsening their stress state compared to flat plates.


Assuntos
Corrida , Sapatos , Corrida/fisiologia , Humanos , Fenômenos Biomecânicos , Pressão , Fibra de Carbono/química , Antepé Humano/fisiologia , Análise de Elementos Finitos , Estresse Mecânico , Suporte de Carga/fisiologia , Carbono/química , Desenho de Equipamento , Pé/fisiologia
17.
eNeuro ; 11(7)2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38918051

RESUMO

Measuring the dynamic relationship between neuromodulators, such as dopamine, and neuronal action potentials is imperative to understand how these fundamental modes of neural signaling interact to mediate behavior. We developed methods to measure concurrently dopamine and extracellular action potentials (i.e., spikes) in monkeys. Standard fast-scan cyclic voltammetric (FSCV) electrochemical (EChem) and electrophysiological (EPhys) recording systems are combined and used to collect spike and dopamine signals, respectively, from an array of carbon fiber (CF) sensors implanted in the monkey striatum. FSCV requires the application of small voltages at the implanted sensors to measure redox currents generated from target molecules, such as dopamine. These applied voltages create artifacts at neighboring EPhys measurement sensors which may lead to misclassification of these signals as physiological spikes. Therefore, simple automated temporal interpolation algorithms were designed to remove these artifacts and enable accurate spike extraction. We validated these methods using simulated artifacts and demonstrated an average spike recovery rate of 84.5%. We identified and discriminated cell type-specific units in the monkey striatum that were shown to correlate to specific behavioral task parameters related to reward size and eye movement direction. Synchronously recorded spike and dopamine signals displayed contrasting relations to the task variables, suggesting a complex relationship between these two modes of neural signaling. Future application of our methods will help advance our understanding of the interactions between neuromodulator signaling and neuronal activity, to elucidate more detailed mechanisms of neural circuitry and plasticity mediating behaviors in health and in disease.


Assuntos
Potenciais de Ação , Fibra de Carbono , Dopamina , Macaca mulatta , Animais , Potenciais de Ação/fisiologia , Dopamina/metabolismo , Masculino , Neurônios/fisiologia , Neurônios/metabolismo , Eletrodos Implantados , Corpo Estriado/fisiologia , Corpo Estriado/metabolismo , Artefatos , Técnicas Eletroquímicas/métodos , Movimentos Oculares/fisiologia , Recompensa
18.
Clin Biomech (Bristol, Avon) ; 117: 106284, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38870878

RESUMO

BACKGROUND: Carbon-fiber custom dynamic orthoses are used to improve gait and limb function following lower limb trauma in specialty centers. However, the effects of commercially available orthoses on center of pressure progression and patient perception of orthosis smoothness during walking are poorly understood. METHODS: In total, 16 participants with a unilateral lower extremity traumatic injury underwent gait analysis when walking without an orthosis, and while wearing monolithic and modular devices, in a randomized order. Device alignment, stiffness, participant rating of perceived device smoothness, center of pressure velocity, and ankle zero moment crossing were assessed. FINDINGS: The modular device was approximately twice as stiff as the monolithic device. Alignment, smoothness ratings, peak magnitude of center of pressure velocity, and zero moment crossing were not different between study devices. The time to peak center of pressure velocity occurred significantly later for the modular device compared to the monolithic and no orthosis conditions, with large effect sizes observed. INTERPRETATION: Commercially available orthoses commonly used to treat limb trauma affect the timing of center of pressure progression relative to walking without an orthosis. Despite multiple design differences, monolithic and modular orthoses included in this study did not differ with respect to other measures of center of pressure progression. Perceived smoothness ratings were approximately 40% greater with the study orthoses as compared to previous studies in specialty centers, which may be due to a more gradual center of pressure progression, as indicted by lower peak magnitude of center of pressure velocity with both study orthoses.


Assuntos
Fibra de Carbono , Aparelhos Ortopédicos , Pressão , Humanos , Masculino , Feminino , Adulto , Carbono/química , Desenho de Equipamento , Marcha , Traumatismos da Perna/fisiopatologia , Extremidade Inferior/fisiopatologia , Pessoa de Meia-Idade , Caminhada , Adulto Jovem
19.
Int J Biol Macromol ; 273(Pt 2): 132921, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38866281

RESUMO

In order to investigate the effect of boron element on liquefied wood carbon fibers and their composites, boric acid and boron carbide were utilized to modify liquefied wood resin through copolymerization and blending methods respectively. Then boric acid-modified liquefied wood carbon fiber (BA-WCF) and boron carbide-modified liquefied wood carbon fiber (BC-WCF) were produced via melt spinning, curing, and carbonization treatments. As expected, this modification approach effectively prevents the formation of skin-core structures and accelerates the evolution of a graphite microcrystalline structure, thereby enhancing the mechanical properties of the carbon fibers. Particularly, the tensile strength and elongation at break of BA-WCF increased to 331.57 MPa and 7.57 % respectively, representing increments of 117 % and 86 % compared to the conventional fibers. Furthermore, the as-fabricated carbon fiber/resin composites (CFPRs), composing of BA-WCF or BC-WCF as fillers and liquefied wood resin as matrix, exhibited excellent interlaminar shear strength, outstanding abrasion resistance, and well thermal conductivity, as well as electrical performance, significantly outperforming the conventional carbon fiber/phenolic resin composites. The friction rate of BC-WP/BA-WCF/CF was 2.37 %, while its thermal conductivity could reach 1.927 W/(m·K). These promising attributes lay the groundwork for the development of high-performance carbon fiber-based materials, fostering their widespread utilization across various industries.


Assuntos
Fibra de Carbono , Condutividade Térmica , Madeira , Fibra de Carbono/química , Madeira/química , Catálise , Resistência à Tração , Compostos de Boro/química , Ácidos Bóricos
20.
J Nanobiotechnology ; 22(1): 377, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38937768

RESUMO

BACKGROUND: Efficient monitoring of glucose concentration in the human body necessitates the utilization of electrochemically active sensing materials in nonenzymatic glucose sensors. However, prevailing limitations such as intricate fabrication processes, lower sensitivity, and instability impede their practical application. Herein, ternary Cu-Co-Ni-S sulfides nanoporous network structure was synthesized on carbon fiber paper (CP) by an ultrafast, facile, and controllable technique through on-step cyclic voltammetry, serving as a superior self-supporting catalytic electrode for the high-performance glucose sensor. RESULTS: The direct growth of free-standing Cu-Co-Ni-S on the interconnected three-dimensional (3D) network of CP boosted the active site of the composites, improved ion diffusion kinetics, and significantly promoted the electron transfer rate. The multiple oxidation states and synergistic effects among Co, Ni, Cu, and S further promoted glucose electrooxidation. The well-architected Cu-Co-Ni-S/CP presented exceptional electrocatalytic properties for glucose with satisfied linearity of a broad range from 0.3 to 16,000 µM and high sensitivity of 6829 µA mM- 1 cm- 2. Furthermore, the novel sensor demonstrated excellent selectivity and storage stability, which could successfully evaluate the glucose levels in human serum. Notably, the novel Cu-Co-Ni-S/CP showed favorable biocompatibility, proving its potential for in vivo glucose monitoring. CONCLUSION: The proposed 3D hierarchical morphology self-supported electrode sensor, which demonstrates appealing analysis behavior for glucose electrooxidation, holds great promise for the next generation of high-performance glucose sensors.


Assuntos
Técnicas Biossensoriais , Fibra de Carbono , Cobalto , Cobre , Técnicas Eletroquímicas , Eletrodos , Níquel , Sulfetos , Cobre/química , Níquel/química , Catálise , Humanos , Cobalto/química , Técnicas Eletroquímicas/métodos , Técnicas Biossensoriais/métodos , Sulfetos/química , Fibra de Carbono/química , Glucose/análise , Glucose/química , Nanoporos , Oxirredução , Glicemia/análise
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