384 research outputs found

    Determination of thyreostats in bovine urine and thyroid glands by HPLC–MS/MS

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    The use of thyreostats in livestock is strictly forbidden by European legislation since 1981. The investigation of thyreostats is commonly performed by their detection as derivatives with 3-iodobenzylbromide. Although it has advantages, the derivatisation procedure can generally cause a decrease in analyte concentrations. With the aim of simplifying the analysis of five thyreostats in both bovine urine and in thyroid glands, two methods were developed without the derivatisation step. Salting-out assisted liquid\u2013liquid extraction was carried out for both matrices, followed by high-performance liquid chromatography coupled with triple-quadrupole mass spectrometry analysis. The methods were validated in agreement with the guidelines of Commission Decision 2002/657/EC. For all the thyreostats evaluated, satisfactory results were achieved; the recovery was within 96\u2013104 % for both the matrices, while precision (coefficient of variation) was less than 20 % for urine and 21 % for thyroid glands. The limits of decision and capacities of detection for all the compounds were lower than the recommended values of 10 \u3bcg L 121 and 10 \u3bcg kg 121, respectively. In urine, the limits of decision ranged from 6.9 to 7.3 \u3bcg L 121, and the capacities of detection ranged from 8.5 to 9.7 \u3bcg L 121, while in thyroid glands these values varied from 6.6 \u3bcg kg 121 to 7.4 \u3bcg kg 121 and from 8.0 \u3bcg g 121 to 9.7 \u3bcg kg 121, respectively. The results obtained show that the methods described are suitable for the direct detection of thyreostats in bovine urine and thyroid glands

    Microbiological quality and resistance to an artificial gut environment of two probiotic formulations

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    The quality control of probiotic products is the focus of numerous organizations worldwide. Several studies have highlighted the poor microbiological quality of many commercial probiotic formulations in terms of the identity of the contained microorganisms, viability, and purity, thus precluding the expected health benefits and representing a potential health risk for consumers. In this paper, we analyzed the contents of two probiotic formulations, one composed of an encapsulated mixture of lactobacilli and bifidobacteria, and one by a lyophilized yeast. The microorganisms contained in the products were quantified and identified using up-to-date methodologies, such as MALDI-TOF MS and metagenomic analysis. Moreover, as acid and bile tolerance is included among the criteria used to select probiotic microorganisms, in vitro tests were performed to evaluate the behavior of the formulations in conditions mimicking the harsh gastric environment and the intestinal fluids. Our results indicate the high quality of the formulations in terms of the enumeration and identification of the contained organisms, as well as the absence of contaminants. Moreover, both products tolerated the acidic conditions well, with encapsulation providing further protection for the microorganisms. A good tolerance to the simulated artificial intestinal conditions was also evidenced for both preparations

    Mesoscopic Stern-Gerlach device to polarize spin currents

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    Spin preparation and spin detection are fundamental problems in spintronics and in several solid state proposals for quantum information processing. Here we propose the mesoscopic equivalent of an optical polarizing beam splitter (PBS). This interferometric device uses non-dispersive phases (Aharonov-Bohm and Rashba) in order to separate spin up and spin down carriers into distinct outputs and thus it is analogous to a Stern-Gerlach apparatus. It can be used both as a spin preparation device and as a spin measuring device by converting spin into charge (orbital) degrees of freedom. An important feature of the proposed spin polarizer is that no ferromagnetic contacts are used.Comment: Updated to the published versio

    Innovation in rehabilitation technology: technological opportunities and socio-economic implications

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    Innovation in stroke rehabilitation technology is discussed that, based on published epidemiological and economic data, represents an urgent case to deal with adopting a multidisciplinary perspective. A theoretical model is proposed for the evaluation of socioeconomic implications related to an early diagnosis and early and timely adjustments in the stroke treatment strategy. The model is applied to the case of a new rehabilitation technology: the ALLADIN diagnostic device. The model compares a traditional approach – ‘trial and error strategy’ – to the innovative one – ‘in progress evaluation’, considering the diagnostic and rehabilitative steps of the patient’s assistive route and assessing social and economic benefits of the innovative device. The new technology allows a precise initial assessment of both the severity of stroke and the level of lost functionality, as long as an evaluation of the expected return from different potential therapies. Moreover, supposing that higher severity of stroke implies higher level of disabilities and social costs, and that the negative impact increases as the level of disability increases, the use of innovative rehabilitation technologies would be more effective in the case of patients with severe and very severe stroke

    Assessing the economic suitability of aeration and the influence of bed heating on constructed wetlands treatment efficiency and life-span

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    Intensive constructed wetlands including forced aeration and heating were studied to improve treatment efficiency and prevent clogging. The experiments were carried out in a pilot plant (0.4 m2) treating urban wastewater with an organic loading rate of 40-60 gCOD/m2∙d. Continuous and intermittent aeration was performed on 8% of the wetland surface, leading to different dissolved oxygen concentrations within the wetlands (from 0.2 to 5 mgO2/L). Continuous forced aeration increased organic matter (COD) and ammonium nitrogen removal by 56% and 69%, respectively. Improvements in 33 wastewater treatment caused by forced aeration can result into reduction of the surface area. This work demonstrated that for the studied configuration the cost of the power consumption of the continuous aeration was largely covered by the reduction of the wetlands surface. Even if the heating of 8% of the wetland surface at 21°C had no effects on treatment performances, positive results showed that solids accumulation rate within the granular medium, which is closely related to the development of clogging. It has been demonstrated that heating for 10 days per year during 20 year period would delay the equivalent of 1 year of solids accumulation

    The effectiveness of neuromuscular warm-up strategies, that require no additional equipment, for preventing lower limb injuries during sports participation: a systematic review

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    PMCID: PMC3408383The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/10/75. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

    A theory of ferromagnetism in planar heterostructures of (Mn,III)-V semiconductors

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    A density functional theory of ferromagnetism in heterostructures of compound semiconductors doped with magnetic impurities is presented. The variable functions in the density functional theory are the charge and spin densities of the itinerant carriers and the charge and localized spins of the impurities. The theory is applied to study the Curie temperature of planar heterostructures of III-V semiconductors doped with manganese atoms. The mean-field, virtual-crystal and effective-mass approximations are adopted to calculate the electronic structure, including the spin-orbit interaction, and the magnetic susceptibilities, leading to the Curie temperature. By means of these results, we attempt to understand the observed dependence of the Curie temperature of planar δ\delta-doped ferromagnetic structures on variation of their properties. We predict a large increase of the Curie Temperature by additional confinement of the holes in a δ\delta-doped layer of Mn by a quantum well.Comment: 8 pages, 7 figure

    Co-ordination between Rashba spin-orbital interaction and space charge effect and enhanced spin injection into semiconductors

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    We consider the effect of the Rashba spin-orbital interaction and space charge in a ferromagnet-insulator/semiconductor/insulator-ferromagnet junction where the spin current is severely affected by the doping, band structure and charge screening in the semiconductor. In diffusion region, if the the resistance of the tunneling barriers is comparable to the semiconductor resistance, the magnetoresistance of this junction can be greatly enhanced under appropriate doping by the co-ordination between the Rashba effect and screened Coulomb interaction in the nonequilibrium transport processes within Hartree approximation.Comment: 4 pages, 3 figure
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