1,146 research outputs found

    Determination of anabolic steroids by differential pulse polarography

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    Determination of anabolic steroids often requires the use of elaborate techniques such as gas chromatography - mass spectrometry (GC-MS), gas liquid chromatography (GLC) and more recently high performance liquid chromatography (HPLC). Most of these methods employ derivatisation techniques prior to detection which makes them tedious and relatively time consuming. Other methods demand a great deal of skill. A simple and rapid analytical method, based on differential pulse polarography at a dropping mercury electrode has been developed for the determination of various anabolic steroids in a range of commercially available pharmaceutical preparations. Detailed investigation of the electrochemical behaviour of these steroids was made in order to elucidate the electrode processes involved, in addition to optimising the method. Several other analytical methods such as GC-MS, NMR, ultraviolet (UV), infrared (IR) spectroscopy were also used to confirm the products of the chemical and electrochemical reactions. Possible reactions are suggested. Various extraction procedures were examined for separation of selected steroids from the oil-based or pill matrix and their suitability for polarographic determination is discussed

    Formation professionnelle et (ré)insertion en Belgique et en Espagne des jeunes espagnols issus de la migration

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    Evaluation of the Performance and Hematocrit Independence of the HemaPEN as a Volumetric Dried Blood Spot Collection Device

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    Dried blood spots (DBS) are often used as a less invasive alternative to venous blood sampling. Despite its numerous advantages, the use of conventional DBS suffers from the hematocrit (hct) effect when analyzing a subpunch. This effect could be avoided by using hct-independent sampling devices, of which the hemaPEN is a recent example. This device collects the blood via four integrated 2.74 μL microcapillaries, each depositing the blood on a prepunched paper disc. In this study, we evaluated the technical performance of the hemaPEN devices, using an extensive bioanalytical validation and application on authentic patient samples. An LC-MS/MS method quantifying caffeine and its metabolite paraxanthine in dried whole blood (using the hemaPEN device) was fully validated, meeting all preset acceptance criteria. A comparative analysis of 91 authentic patient samples (hct range: 0.17–0.53) of hemaPEN, 3 mm DBS subpunches, and whole blood revealed a limited hct dependence (≤7% concentration difference over a 0.20–0.50 hct range) for the hemaPEN devices, which we could not attribute to the analytical procedure. Using conventional partial-punch DBS (3 mm punches), concentration differences of ≥25% over this hct range were found. The hemaPEN showed to be robust to the effects of blood sample volume, device lot, analytical operator, and storage stability. The technical performance of the hemaPEN when dealing with patients having a high hct and in cases where a large blood drop is present should be further investigated. Based on the successful validation and application on patient samples, we conclude that the hemaPEN device shows good potential for the volumetric collection of DBS.S.D. would like to thank the Research Foundation-Flanders (FWO) for granting her a PhD fellowship (application number:11F3119N). L.P.-G. would like to thank the Consellería de Cultura, Educacion e Ordenación Universitaria, Xunta de Galicia, for her predoctoral (ED481A-2018/059) contractS

    Does Long-Term GPS in the Western Alps Finally Confirm Earthquake Mechanisms?

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    International audienceThe availability of GPS survey data spanning 22 years, along with several independent velocity solutions including up to 16 years of permanent GPS data, presents a unique opportunity to search for persistent (and thus reliable) deformation patterns in the Western Alps, which in turn allow a reinterpretation of the active tectonics of this region. While GPS velocities are still too uncertain to be interpreted on an individual basis, the analysis of range‐perpendicular GPS velocity profiles clearly highlights zones of extension in the center of the belt (15.3 to 3.1 nanostrain/year from north to south), with shortening in the forelands. The contrasting geodetic deformation pattern is coherent with earthquake focal mechanisms and related strain/stress patterns over the entire Western Alps. The GPS results finally provide a reliable and robust quantification of the regional strain rates. The observed vertical motions of 2.0 to 0.5 mm/year of uplift from north to south in the core of the Western Alps is interpreted to result from buoyancy forces related to postglacial rebound, erosional unloading, and/or viscosity anomalies in the crustal and lithospheric root. Spatial decorrelation between vertical and horizontal (seismicity related) deformation calls for a combination of processes to explain the complex present‐day dynamics of the Western Alps

    Contribution of genetic defects in pancreatitis in Belgians: 10 years experience

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    Promoting Stakeholder Participation in a Learning-Based Monitoring and Evaluation Framework

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    This research analysed monitoring and evaluation activities based on the Outcome Mapping methodology within the Zimbabwe Secondary Teacher Training Environmental Education Project (St2eep), an education for sustainability initiative in Zimbabwe. The majority of donorfunded environmental education programmes use conventional monitoring and evaluation approaches based on the logical frameworks (logframe) that guide the programme designs and management. Although research indicates significant problems with the implementation of these approaches, there are only a few documented examples of experiences with alternative monitoring and evaluation frameworks. The case of St2eep allowed us to compare three years of experiences with monitoring and evaluation based on the logframe, with two years of monitoring and evaluation based on Outcome Mapping. We evaluate how the project team and the donor organisation, VVOB (the Flemish Office for Development, Cooperation and Technical Assistance), have perceived the performance of Outcome Mapping with regards to the two main aims of monitoring and evaluation activities: accountability and learning. This is complemented with an analysis of monitoring documentation. The project team refers to the collaborative nature of monitoring and evaluation in St2eep, the principles of self-assessment and peer-assessment, combined with public recognition for project successes, as the key factors supporting learning and accountability through monitoring and evaluation in St2eep. The Outcome Mapping-based monitoring and evaluation system is shown to enhance ownership and participation of local stakeholders in the project’s monitoring and evaluation system

    Acetabular osteoid osteoma treated by percutaneous radio - frequency ablation: delayed articular cartilage damage

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    The authors report the case of an osteoid osteoma of the acetabular roof in a 17-year-old sportsgirl successfully treated by radiofrequency ablation, with a mid-term evidence of cartilage loss. Extra-articular access and exact positioning of the needle electrode exclude direct operative chondral damage. Intense physical activity could be an aggravating factor for the chondropathy. It is difficult to determine whether the acetabular cartilage joint was damaged only by thermo-ablation or if it had also been weakened before by the O.O. The authors caution practitioners from using this technique for para-articular lesions, especially near weight-bearing joints

    Online monitoring of the impact of language processing on motor processes: prehensile grip-force measures during passive listening of manual action.

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    A large number of recent behavioural studies have established that processing linguistic descriptions of motor actions affect overt motor behaviour. For instance, when participants are asked to make sensibility judgments on sentences that describe action toward the body (“Mark gave the book to yo
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