Electrochemical Determination of 17-β-Estradiol Using a Glassy Carbon Electrode Modified with α-FeO Nanoparticles Supported on Carbon Nanotubes.

In this study, a novel electrochemical assay for determining 17-β-estradiol (E2) was proposed. The approach involves modifying a glassy carbon electrode (GCE) with a nanocomposite consisting of α-FeO nanoparticles supported on carbon nanotubes (CNTs)-denoted as α-FeO-CNT/GCE. The synthesis of the α-FeO-CNT nanocomposite was achieved through a simple and cost-effective hydrothermal process.

Visible Light Photoelectrochemical Sensor for Dopamine: Determination Using Iron Vanadate Modified Electrode.

This study reports a facile approach for constructing low-cost and remarkable electroactivity iron vanadate (Fe-V-O) semiconductor material to be used as a photoelectrochemical sensor for dopamine detection. The structure and morphology of the iron vanadate obtained by the Successive Ionic Adsorption and Reaction process were critically characterized, and the photoelectrochemical characterization showed a high photoelectroactivity of the photoanode in visible light irradiation. Under best conditions, dopamine was detected by chronoamperometry at +0.

Efficient removal of glyphosate from aqueous solutions by adsorption on Mg-Al-layered double oxides: thermodynamic, kinetic, and mechanistic investigation.

Up to 90% of glyphosate was removed in 40 min by a 2:1 MgAl-layered double oxide (LDO) at pH 10, and the adsorption kinetics fitted a pseudo-second-order law. The adsorption isotherms were type L, and the Langmuir model best fitted the experimental data, with q of 158.22 μg/mg at 25 °C.

A nonenzymatic biosensor based on gold electrodes modified with peptide self-assemblies for detecting ammonia and urea oxidation.

We have developed a nonenzymatic biosensor for the detection of ammonia and urea oxidation based on the deposition of peptide microstructures onto thiolated gold electrodes. FF-MNSs/MCP/Au assemblies were obtained by modifying gold substrates with 4-mercaptopyridine (MCP), followed by coating with l,l-diphenylalanine micro/nanostructures (FF-MNSs) grown in the solid-vapor phase. Benzene rings and amide groups with peptide micro/nanostructures interact with synthetic NH4(+) receptors through cation-π and hydrogen bonding.

A highly improved method for sensitive determination of amitriptyline in pharmaceutical formulations using an unmodified carbon nanotube electrode in the presence of sulfuric acid.

The present paper describes a novel, simple and reliable differential pulse voltammetric method for determining amitriptyline (AMT) in pharmaceutical formulations. It has been described for many authors that this antidepressant is electrochemically inactive at carbon electrodes. However, the procedure proposed herein consisted in electrochemically oxidizing AMT at an unmodified carbon nanotube paste electrode in the presence of 0.

Lipase production by Botryosphaeria ribis EC-01 on soybean and castorbean meals: optimization, immobilization, and application for biodiesel production.

The effects of soybean and castorbean meals were evaluated separately, and in combinations at different ratios, as substrates for lipase production by Botryosphaeria ribis EC-01 in submerged fermentation using only distilled water. The addition of glycerol analytical grade (AG) and glycerol crude (CG) to soybean and castorbean meals separately and in combination, were also examined for lipase production. Glycerol-AG increased enzyme production, whereas glycerol-CG decreased it.

Geophysical technique and groundwater monitoring to detect leachate contamination in the surrounding area of a landfill--Londrina (PR--Brazil).

The aim of the present study was to define leachate plume by using two techniques: geophysical and groundwater sampling in order to evaluate groundwater contamination. After performing a topographic survey and using geophysics, the leachate plume was identified. With this data, the wells for groundwater monitoring were located.

Sex-specific foraging behaviour in a monomorphic seabird.

Sexual differences in the foraging behaviour of parents have been observed in a number of sexually sizedimorphic birds, particularly seabirds, and the usual inference has been that these sex-specific differences are mediated primarily by differences in body size. To test this explanation, we compared the foraging behaviour of parents in a monomorphic seabird species, the northern gannet Morus bassanus. Using specially designed instruments and radio telemetry we found that individuals of both sexes were consistent in the directions and durations of their foraging trips.

Tracking clock-shifted homing pigeons from familiar release sites.

Clock-shifted homing pigeons were tracked from familiar sites 17.1 km and 23.5 km from the home loft in Pisa, Italy, using an on-board route recorder.

Pigeon homing: site simulation experiments with bird-borne direction recorders.

Previous experiments showed that pigeons allowed to smell olfactory cues at a 'false' release site, and subsequently transported to and released from another unfamiliar locality, oriented according to the home direction at the false site but eventually homed despite their wrong initial orientation. In the above 'site simulation' experiments, data collection was restricted to the initial bearings and homing performance, and no information was obtained on the actual route flown by pigeons. Route correction in site simulation tests is now investigated by releasing pigeons equipped with bird-borne direction recorders to track their route.

Pigeon homing: The influence of topographical features in successive releases at the same site.

A new device, the direction-recorder, offered the possibility to extend earlier studies of homing behaviour of pigeons when relevant topographical elements (mountains and large tracts of water) interpose between the release site and the home loft. Three series of experiments were carried out at three different sites to investigate intraindividual and interindividual variability in subsequent tosses from the same locality. Two release sites were chosen behind a mountain chain with respect to home; at the third site homeward directed route crosses the sea.