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1.
Front Neurosci ; 13: 456, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31156363

RESUMO

Importance: Accumulating evidence suggests that serum levels of S100B may play a role in epilepsy. Objective: We performed a meta-analysis to quantitatively summarize the serum S100B data available for patients with epilepsy. Data source: Two independent researchers conducted a systematic investigation of the Harvard Hollis+, Open Gray, Clinicaltrials, Wanfangdata, and CNKI databases through Dec 6, 2018, for all studies published in English and Chinese. The search terms included S100B and calcium-binding protein B in combination with epilepsy. Study selection: Original studies and reported data from these search terms are included. Studies where data overlapped with other studies were excluded. Data extraction and synthesis: investigators extracted, pooled and analyzed data from the included studies using a fixed-effects model in the Comprehensive Meta-Analysis3.3 and R software. Main outcomes and measures: Peripheral blood levels of S100B in patients with epilepsy compared with controls. Aberrations in peripheral blood levels of S100B were hypothesized to be related to epilepsy. Results: a fixed-effects meta-analysis of all 18 studies, including 1,057 unique participants, indicated that patients with epilepsy had significantly increased peripheral blood levels of S100B compared to controls (Hedges g = 1.568, 95% CI =1.431-1.706, P < 0.001). Sensitivity analysis showed that no single study significantly influenced the overall association of peripheral blood levels of S100B and epilepsy. Most of the subgroup analyses, including those of country, assay type and publication language, demonstrated a statistically significant association between peripheral blood levels of S100B and epilepsy. Meta-regression analyses indicated that gender (regression coefficient [SE], -0.2524 [0.0641]; 95%CI, -0.3781 to -0.1267; P = 0.0001) and mean age (regression coefficient [SE], -0.1224 [0.0426]; 95% CI, -0.2058 to -0.0390; P = 0.0040) might present serum S100B reductions, but sample size, years, assay type, publication language and country did not show moderating effects on the effect sizes. Furthermore, the trim-and-fill method used to adjust for funnel plot asymmetry in our meta-analysis confirmed that a positive outcome is unlikely to be due to publication bias. Conclusion and relevance: the results of this meta-analysis provide evidence for a significant increase in serum S100B levels in patients with epilepsy. Serum S100B is the most worthwhile biomarker of epilepsy, which is helpful for the clinical diagnosis and prognosis of epilepsy.

2.
Spectrochim Acta A Mol Biomol Spectrosc ; 207: 337-347, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30267978

RESUMO

In this work, we develop a simple and selective sensing method for the detection of mercury ions based on surface plasmon resonance (SPR) spectrum change of Au-Ag core-shell triangular nanoplates. When the concentration of mercury is increased, the etching-induced change of particle size and shape also leads to the decrease of the absorption peak at the fixed wavelength, until a spectrum dip takes place. This spectral change of "peak-to-dip" greatly enlarges the detection range of mercury ions, which could be fine tuned by changing the initial thickness of the Ag coating. Under optimal conditions, the decrease of the logarithmic absorption intensity has a good linear response with the concentration of mercury ions increasing from 10 to 1000 µM, and the limit of detection (LOD) is 0.88 µM. Interference studies and real samples test indicate that, this new sensing method has a good selection for mercury ions and can be practically used in lake water. This work shows the surface etching-induced SPR shift can also leads to the intensity change with "peak-to-dip" fashion, which greatly enlarge the concentration range of the detection and could be widely applied in the spectroscopy sensing based on SPR.

3.
Sci Rep ; 6: 20971, 2016 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-26860967

RESUMO

Based on the first-principles calculations, we have investigated in detail the bandgap opening of silicene nanomeshes. Different to the mechanism of bandgap opening induced by the sublattice equivalence breaking, the method of degenerate perturbation through breaking the bond symmetry could split the π-like bands in the inversion symmetry preserved silicene nanomeshes, resulting into the πa1 - πa2 and πz1 - πz2 band sets with sizable energy intervals. Besides the bandgap opening in the nanomeshes with Dirac point being folded to Γ point, the split energy intervals are however apart away from Fermi level to leave the semimetal nature unchanged for the other nanomeshes with Dirac points located at opposite sides of Γ point as opposite pseudo spin wave valleys. A mass bandgap could be then opened at the aid of uniaxial strain to transfer the nanomesh to be semiconducting, whose width could be continuously enlarged until reaching its maximum Emax. Moreover, the Emax could also be tuned by controlling the defect density in silicene nanomeshes. These studies could contribute to the understanding of the bandgap engineering of silicene-based nanomaterials to call for further investigations on both theory and experiment.

4.
Sci Rep ; 6: 18869, 2016 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-26732904

RESUMO

Using the density functional theory with generalized gradient approximation, we have studied in detail the cooperative effects of degenerate perturbation and uniaxial strain on bandgap opening in graphene. The uniaxial strain could split π bands into πa and πz bands with an energy interval Es to move the Dirac cone. The inversion symmetry preserved antidot would then further split the πa (πz) bands into πa1 (πz1) and πa2 (πz2) bands with an energy interval Ed, which accounts for the bandgap opening in a kind of superlattices with Dirac cone being folded to Γ point. However, such antidot would not affect the semimetal nature of the other superlattices, showing a novel mechanism for bandstructure engineering as compared to the sublattice-equivalence breaking. For a superlattice with bandgap of ~Ed opened at Γ point, the Es could be increased by strengthening strain to close the bandgap, suggesting a reversible switch between the high velocity properties of massless Fermions attributed to the linear dispersion relation around Dirac cone and the high on/off ratio properties associated with the sizable bandgap. Moreover, the gap width actually could be continuously tuned by controlling the strain, showing attractive application potentials.

5.
Biosens Bioelectron ; 25(7): 1803-8, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-20080042

RESUMO

A nonenzymatic electrochemical method was developed for glucose detection using an electrode modified with palladium nanoparticles (PdNPs)-functional carbon nanotubes (FCNTs). PdNPs were homogeneously modified on FCNTs through a facile spontaneous redox reaction and characterized by transmission electron microscopy. Based on the voltammetric and amperometric results, PdNPs efficiently catalyzed the oxidation of glucose at 0.40 V in the presence of 0.2M NaCl and showed excellent resistance towards poisoning from such interfering species as ascorbic acid, uric acid, and p-acetamidophenol. This anti-poisoning ability was investigated using analysis of the electrocatalytic products by in situ subtractively normalized interfacial Fourier transform infrared reflection spectroscopy, and the results indicated that no strongly adsorbed CO(ad) species could be found in the oxidation products, which was obviously different from the results obtained using Pt-based electrodes. In order to verify the sensor reliability, it was applied to the determination of glucose in urine samples. The results indicated that the proposed approach provided a highly sensitive, wide linear range, more facile method with good reproducibility for glucose determination, promising the development of Pd-based material in nonenzymatic glucose sensing.


Assuntos
Técnicas Biossensoriais/instrumentação , Condutometria/instrumentação , Eletrodos , Glucose/análise , Nanotecnologia/instrumentação , Nanotubos de Carbono/química , Paládio/química , Técnicas Biossensoriais/métodos , Condutometria/métodos , Enzimas/química , Desenho de Equipamento , Análise de Falha de Equipamento , Glucose/química , Nanotubos de Carbono/ultraestrutura , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
Anal Chim Acta ; 650(1): 54-8, 2009 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-19720173

RESUMO

In this study, a novel material, palladium nanoparticles-carboxylic functional carbon nanotubes (PdNPs-CFCNTs), based on PdNPs supported on CFCNTs was synthesized by a facile spontaneous redox method. The material reveals high electrochemical activity and excellent catalytic characteristic for alcohol electrooxidation on a glassy carbon electrode (GCE) in an alkaline medium. The preparation mechanism was studied by the galvanic cell effect between PdCl(4)(2-) and functional defect sites on CFCNTs. Results from UV-visible absorption spectroscopy and electrochemical impedance spectroscopy revealed that the reduction of PdCl(4)(2-) to metallic Pd was successfully achieved. Morphologies of PdNPs supporting on CFCNTs (PdNPs-CFCNTs) were also characterized by transmission electron micrograph. PdNPs-CFCNTs with the best electrocatalytic characteristics were obtained under the condition as: the weight ratio of Pd to CFCNTs was kept at 2:1, the temperature was kept at 70 degrees C in the synthesis, and the scan rate of the applied potential was selected at 60 mV s(-1). The results indicate that PdNPs-CFCNTs could be a great potential material in direct ethanol fuel cells and ethanol sensors.

7.
Biosens Bioelectron ; 25(1): 263-7, 2009 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-19616932

RESUMO

An ethanol biosensor, based on the electrogenerated chemiluminescence of Ru(bpy)(3)(2+)-doped silica nanoparticles (RuSiNPs), was investigated in this study. The biosensor was a modified glassy carbon electrode, where alcohol dehydrogenase was crosslinked to RuSiNPs, and then immobilized on the electrode surface using chitosan. The results indicated that the biosensor exhibited excellent performance during ethanol determination with a wide linear range (10(-7) to 10(-2) M), low detection limit (5.0x10(-8) M) and good stability.


Assuntos
2,2'-Dipiridil/análogos & derivados , Álcool Desidrogenase/metabolismo , Técnicas Biossensoriais/métodos , Etanol/análise , Nanopartículas/química , Dióxido de Silício/química , 2,2'-Dipiridil/química , Complexos de Coordenação , Eletroquímica/métodos , Luminescência , Saccharomyces cerevisiae/enzimologia , Sensibilidade e Especificidade
8.
Biosens Bioelectron ; 24(12): 3475-80, 2009 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-19482465

RESUMO

A novel non-enzymatic electrochemiluminescence (ECL) sensor based on palladium nanoparticles (PdNPs)-functional carbon nanotubes (FCNTs) was discovered for glucose detection. PdNPs were homogeneously modified on FCNTs using a facile spontaneous redox reaction method. Their morphologies were characterized by transmission electron microscopy (TEM). Based on ECL experimental results, the PdNPs-FCNTs-Nafion film modified electrode displayed high electrocatalytic activity towards the oxidation of glucose. The free radicals generated by the glucose oxidation reacted with the luminol anion (LH(-)), and enhanced the ECL signal. Under the optimized conditions, the linear response of ECL intensity to glucose concentration was valid in the range from 0.5 to 40 micromol L(-1) (r(2)=0.9974) with a detection limit (S/N=3) of 0.09 micromol L(-1). In addition, the modified electrode presented high resistance towards the poisoning of chloride ion, high selectivity and long-term stability. In order to verify the sensor reliability, it was applied to the determination of glucose in glucose injection samples. The results indicated that the proposed approach provided a highly sensitive, more facile method with good reproducibility for glucose determination, promising the development of a non-enzymatic ECL glucose sensor.


Assuntos
Técnicas Biossensoriais/instrumentação , Eletroquímica/instrumentação , Glucose/análise , Medições Luminescentes/instrumentação , Nanopartículas/química , Nanotubos de Carbono/química , Paládio/química , Desenho de Equipamento , Análise de Falha de Equipamento , Glucose/química , Nanopartículas/ultraestrutura , Nanotubos de Carbono/ultraestrutura
9.
Anal Chem ; 81(2): 830-3, 2009 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-19067540

RESUMO

A colorimetric electrochemiluminescence (ECL) sensor was fabricated for the first time, based on a dual-color system including a strong red Ru(bpy)(3)(2+) ECL and a green reference light from a light emitting diode. Traditional ECL intensity information can be easily transformed into a color variation with this sensor, and the color variation can be directly monitored using the naked eye or a commercial CCD camera. The sensor has been successfully used to determine the concentration of tripropylamine, proline (enhancing system), and dopamine (quenching system). The results indicated that the color variation obtained corresponded to the concentration of target analytes. This sensor has potential application in rapid and semiquantitative ECL analysis.

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