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1.
Nanotechnology ; 28(29): 295704, 2017 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-28574399

RESUMO

In this work, we have prepared CeO2/Co3O4 composite nanofibers via an electrospinning technique followed by a calcination process. Then core-shell structured CeO2/Co3O4/poly(3,4-ethylenedioxythiophene) (PEDOT) composite nanofibers were fabricated through a redox reaction between the 3,4-ethylenedioxythiophene (EDOT) monomer and Co3O4 on the surface of CeO2/Co3O4 composite nanofibers. The morphology and composition of the two composite nanofibers were confirmed by field-emission scanning electron microscopy, transmission electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy, and x-ray photoelectron spectra measurements. Due to the synergistic effect between CeO2 and Co3O4, the catalytic activity was enhanced compared to that of independent oxide nanofibers. After the growth of PEDOT, the catalytic activity process was further improved, having achieved a secondary synergistic effect. Application of the two prepared composite nanofibers as peroxidase-like catalysts for the colorimetric detection of H2O2 was investigated. It is anticipated that this work can inspire researchers to develop various novel functional nanocomposites for applications in biosensing and environmental monitoring.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/química , Cério/química , Cobalto/química , Peróxido de Hidrogênio/química , Nanocompostos/química , Nanofibras/química , Óxidos/química , Polímeros/química , Catálise
2.
Chem Commun (Camb) ; 54(46): 5827-5830, 2018 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-29670955

RESUMO

A self-templated approach has been developed for the preparation of FeMnO3 nanoparticles filled in the hollow core of polypyrrole (PPy) nanotubes by an in situ polymerization process accompanied by the etching of FeMnO3 nanofibers. The prepared FeMnO3@PPy nanotubes exhibited a superior peroxidase-like activity. The catalytic reaction system has been used for the sensitive colorimetric detection of glutathione with a low detection limit and good selectivity.


Assuntos
Materiais Biomiméticos/química , Glutationa/sangue , Nanopartículas/química , Nanotubos/química , Polímeros/química , Pirróis/química , Benzidinas/química , Materiais Biomiméticos/síntese química , Catálise , Colorimetria , Compostos Férricos/química , Humanos , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Cinética , Limite de Detecção , Compostos de Manganês/química , Nanofibras/química , Oxirredução , Óxidos/química , Peroxidase/química , Polímeros/síntese química , Pirróis/síntese química , Difração de Raios X
3.
Dalton Trans ; 46(34): 11171-11179, 2017 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-28812762

RESUMO

Synergistic effects play an important role in improving the catalytic activity for enzyme-like reactions. Compared to individual nanomaterials, a system consisting of multiple components usually exhibits enhanced catalytic activity as an enzyme mimic. Herein we describe the synthesis of CuFe2O4/Cu9S8/polypyrrole (PPy) ternary nanotubes as an efficient peroxidase mimic via a three-step approach involving an electrospinning process, annealing treatment and hydrothermal reaction. The remarkably enhanced catalytic activity of CuFe2O4/Cu9S8/PPy ternary nanotubes as peroxidase mimics over individual CuFe2O4 nanofibers, CuFe2O4/CuO composite nanofibers, CuFe2O4/CuS composite nanofibers, and PPy materials has been achieved, demonstrating the presence of a synergistic effect among the components. The steady-state kinetic experiment suggests a good catalytic efficiency of the CuFe2O4/Cu9S8/PPy ternary nanotubes. On the basis of high catalytic activity, a colorimetric platform for the sensitive detection of H2O2 and dopamine has been developed. This work not only offers a simple approach for the fabrication of a high performance peroxidase-like nanocatalyst, but also provides its promising potential applications in biosensors, medical diagnosis, and environmental monitoring.


Assuntos
Colorimetria/métodos , Cobre/química , Dopamina/análise , Compostos Ferrosos/química , Peróxido de Hidrogênio/análise , Limite de Detecção , Nanotubos/química , Polímeros/química , Pirróis/química , Materiais Biomiméticos/química , Técnicas de Química Sintética , Dopamina/química , Peróxido de Hidrogênio/química , Peroxidase/metabolismo
4.
Head Face Med ; 12(1): 31, 2016 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-27821165

RESUMO

BACKGROUND: Class III malocclusion is a maxillofacial disorder that is characterised by a concave profile and can be attributed to both genetic inheritance and environmental factors. It is a clinical challenge due to our limited understanding of its aetiology. Revealing its prototypical diversity will contribute to our sequential exploration of the underlying aetiological information. The objective of this study was to characterize phenotypic variations of Class III malocclusion via a lateral cephalometric analysis in a community of Chinese individuals. METHOD: One-hundred-and-forty-four individuals (58 males ≥18 and 86 females ≥16) with Class III malocclusion ranging from mild to severe were enrolled in this study. Principal component analysis and cluster analysis were performed using 61 lateral cephalometric measurements. RESULTS: Six principal components were discovered in the examined population and were responsible for 73.7 % of the variability. Four subtypes were revealed by cluster analysis. Subtype 1 included subjects with mild mandibular prognathism with a steep mandibular plane. Subjects in subtype 2 showed a combination of prognathic mandibular and retrusive maxillary with a flat or normal mandibular plane. Subtype 3 included individuals with purely severe mandibular prognathism and a normal mandibular plane. Individuals in subtype 4 had a mild maxillary deficiency and severe mandibular prognathism with the lowest mandibular plane angle. CONCLUSION: The six principal components extracted among the 61 variables improve our knowledge of lateral cephalometric analysis for diagnoses. We successfully identified four Class III malocclusion subtypes, indicating that cluster analysis could supplement the classification of Class III malocclusion among a Chinese population and may assist in our on-going genetic study.


Assuntos
Povo Asiático/genética , Má Oclusão Classe III de Angle/classificação , Adolescente , Adulto , Análise de Variância , Povo Asiático/estatística & dados numéricos , Cefalometria/métodos , Análise por Conglomerados , Estudos de Coortes , Feminino , Hospitais Universitários , Humanos , Estudos Longitudinais , Masculino , Má Oclusão Classe III de Angle/etnologia , Má Oclusão Classe III de Angle/genética , Análise Multivariada , Análise de Componente Principal , Índice de Gravidade de Doença , Adulto Jovem
5.
Head Face Med ; 10: 33, 2014 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-25159036

RESUMO

INTRODUCTION: To compare the lip closing force of patients with mandibular prognathism to that of patients without dentofacial anomalies. METHODS: The subject group included 62 female patients of Class III relationship with mandibular prognathism. The control group been comprised of 71 patients of Class I relationships without skeletal deformities. Maximum lip closing force and average lip closing force were measured using a Y-meter. Student's t-test was carried out to analyse the differences between the groups. Correlation and stepwise multiple linear regression analyses were performed to analyse the relationship between lip closing force and craniofacial morphology. RESULTS: The lower lip closing force of subjects with mandibular prognathism was significantly greater than that of patients in the control group (P < 0.001), while the upper lip closing force showed no difference (P > 0.05). The lower lip closing force of patients with mandibular prognathism was strongly correlated with IMPA (Lower Incisor - Mandibular Plane angle, P < 0.001) and FMA (Frankfort Plane-Mandibular Plane angle, P < 0.001). Multiple regression equations: (MaxLL) = 12.192 - 0.125 * (IMPA) + 0.082 (FMA); (AveLL) = 9.112 - 0.091 * (IMPA) + 0.054 (FMA). CONCLUSIONS: The lower lip closing force was markedly increased in Class III patients with mandibular prognathism and was strongly correlated with lower incisor position and mandibular plane angle.


Assuntos
Lábio/fisiopatologia , Mandíbula/anormalidades , Prognatismo/fisiopatologia , Cefalometria , Feminino , Seguimentos , Humanos , Desenvolvimento Maxilofacial , Prognatismo/diagnóstico , Estudos Retrospectivos , Índice de Gravidade de Doença
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