1,698 research outputs found

    Petrographic and crystallographic study of silicate minerals in lunar rocks

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    Optical U-stage measurements, chemical microprobe data, and X-ray procession photographs of a bytownite twin group from rock 12032,44 are compared. Sharp but weak b and no c-reflections were observed for this An89 bytownite indicating a partly disordered structure. Euler angles, used to characterize the orientation of the optical indicatrix, compare better with values for plutonic than for volcanic plagioclase. This indicates that structural and optical properties cannot be directly correlated

    Vitamin E content of different animal products: Influence of animal nutrition

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    Zusammenfassung: In der vorliegenden Studie wurde der α-Tocopherolgehalt verschiedener Fleischstücke untersucht. Hähnchenschenkel hatte den höchsten α-Tocopherolgehalt, gefolgt von Hähnchenbrust und Schweineschulter (p Leber > Fettgewebe >Musculus longissimus dorsi. Die Nährstoffdichten betrugen 28.8, 7.3, 0.9 und 1.2 mg α-Tocopherol/MJ für Eigelb, Leber, Fettgewebe und Musculus longissimus dorsi der jeweiligen mit Vitamin E supplementierten Gruppe. Diese Ergebnisse zeigen, daß Fleisch, mit Ausnahme des Hähnchenschenkels, von Tieren mit supplementierten Diäten kein bedeutender Vitamin E-Lieferant ist. Hingegen wurde Eigelb durch fütterungsbedingte Modifikation zu einer guten Vitamin E-Quell

    Plasma concentration monitoring of aminoglycosides

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    A narrow therapeutic margin and poor predictability of plasma concentrations are the main reasons for drug level monitoring during aminoglycoside treatment. Gentamicin, tobramycin, amikacin and netilmicin can now be accurately and rapidly measured by radioenzymic, radio-immuno and enzyme-immuno assays. Routine determinations of peak (1-2 h post dose) and trough levels are recommended to ensure adequate dosage in all patients with serious Gram-negative infections, especially when renal function is impaired. It should be realized, however, that maintaining aminoglycoside concentrations within a given range will only reduce, but not entirely eliminate the risk of toxicity. The pharmaco kinetic behaviour of these antibiotics leads to a progressive drug accumulation in renal tissue and the inner ear, which depends both on dosage amd duration of treatment. Une marge thérapeutique étroite ainsi que la difficulté a prédire les concentration plasmatiques, sont les principales raisons de contrôle des taux sanguins au cours d'un traitement par les aminoglycosides. Aujourd'hui les concentrations de gentamicine, tobramycine, amikacine et nétilmicine peuvent ětre mesurées rapidement et de manière précise par les méthodes radio-enzymatiques, radio immunologiques et enzymo-immunologiques. La détermination du pic (1 à 2 heures après administration) et du taux résiduel est recommandée pour assurer un dosage adéquat chez tous les malades atteints d'une infection sevère à germes Gram-négatif, et particulièrement en cas d'insuffisance rénale. Il faut pourtant bien garder à l'esprit, que le fait de maintenir la concentration d'une aminoglycoside à un niveau donné, permet seulement de diminuer les risques de toxicité, mais pas de les éliminer totalement. La pharmacocinétique particulière de ces antibiotiques entraine une accumulation progressive dans le parenchyme renal et dans l'oreille interne, qui depend à la fois de la posologie et de la durée du traitemen

    Developing and validating a new comprehensive glucose-insulin pharmacokinetics and pharmacodynamics model

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    Type 2 diabetes has reached epidemic proportions worldwide. The resulting increase in chronic and costly diabetes related complications has potentially catastrophic implications for healthcare systems, and economics and societies as a whole. One of the key pathological factors leading to type 2 diabetes is insulin resistance (IR), which is the reduced or impaired ability of the body to make use of available insulin to maintain safe glucose concentrations in the bloodstream. It is essential to understand the physiology of glucose and insulin when investigating the underlying factors contributing to chronic diseases such as diabetes and cardiovascular disease. For many years, clinicians and researchers have been working to develop and use model-based methods to increase understanding and aid therapeutic decision support. However, the majority of practicable tests cannot yield more than basic metrics that allow only a threshold-based assessment of the underlying disorder. This thesis gives an overview on several dynamic model-based methodologies with different clinical applications in assessing glycaemia via measuring effects of treatment or medication on insulin sensitivity. Other tests are clinically focused, designed to screen populations and diagnose or detect the risk of developing diabetes. Thus, it is very important to observe sensitivity metrics in various clinical and research settings

    Fusarium mycotoxin-contaminated wheat containing deoxynivalenol alters the gene expression in the liver and the jejunum of broilers

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    The effects of mycotoxins in the production of animal feed were investigated using broiler chickens. For the feeding trial, naturally Fusarium mycotoxin-contaminated wheat was used, which mainly contained deoxynivalenol (DON). The main effects of DON are reduction of the feed intake and reduced weight gain of broilers. At the molecular level, DON binds to the 60 S ribosomal subunit and subsequently inhibits protein synthesis at the translational level. However, little is known about other effects of DON, for example, at the transcriptional level. Therefore, a microarray analysis was performed, which allows the investigation of thousands of transcripts in one experiment. In the experiment, 20 broilers were separated into four groups of five broilers each at day 1 after hatching. The diets consisted of a control diet and three diets with calculated, moderate concentrations of 1.0, 2.5 and 5.0 mg DON/kg feed, which was attained by exchanging uncontaminated wheat with naturally mycotoxin-contaminated wheat up to the intended DON concentration. The broilers were held at standard conditions for 23 days. Three microarrays were used per group to determine the significant alterations of the gene expression in the liver (P < 0.05), and qPCR was performed on the liver and the jejunum to verify the results. No significant difference in BW, feed intake or feed conversion rate was observed. The nutrient uptake into the hepatic and jejunal cells seemed to be influenced by genes: SLC2A5 (fc: −1.54, DON2.5), which facilitates glucose and fructose transport and SLC7A10 (fc: +1.49, DON5), a transporter of d-serine and other neutral amino acids. In the jejunum, the palmitate transport might be altered by SLC27A4 (fc: −1.87, DON5) and monocarboxylates uptake by SLC16A1 (fc: −1.47, DON5). The alterations of the SLC gene expression may explain the reduced weight gain of broilers chronically exposed to DON-contaminated wheat. The decreased expressions of EIF2AK3 (fc: −1.29, DON2.5/5) and DNAJC3 (fc: −1.44, DON2.5) seem to be related to the translation inhibition. The binding of DON to the 60 S ribosomal subunit and the subsequent translation inhibition might be counterbalanced by the downregulation of EIF2AK3 and DNAJC3. The genes PARP1, MPG, EME1, XPAC, RIF1 and CHAF1B are mainly related to single-strand DNA modifications and showed an increased expression in the group with 5 mg DON/kg feed. The results indicate that significantly altered gene expression was already occurring at 2.5 mg DON/kg fee

    Advances in clinical application of lipidomics in healthy ageing and healthy longevity medicine

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    It is imperative to optimise health and healthspan across the lifespan. The accumulation of reactive oxygen species (ROS) has been implicated in the hallmarks of ageing and inhibiting ROS production can potentially delay ageing whilst increasing healthy longevity. Lipids and lipid mediators (derivatives of lipids) are becoming increasingly recognized as central molecule in tissue and cellular function and are susceptible to peroxidation; hence linked with ageing. Lipid classes implicated in the ageing process include sterols, glycerophospholipids, sphingolipids and the oxidation products of polyunsaturated fatty acids but these are not yet translated into the clinic. Further mechanistic studies are required for the understanding of lipid classes in the ageing process. Lipidomics, the system level characterisation of lipid species with respect to metabolism and function, might provide a significant and useful biological age profiling tool through longitudinal studies. Lipid profiles in different ages among healthy individuals could be harnessed as lipid biomarkers of healthy ageing with potential integration for the development of lipid-based ageing clock (lipid clock). The potential of a lipid clock includes the prediction of future morbidity or mortality, which will promote precision and healthy longevity medicine

    Regional wave propagation using the discontinuous Galerkin method

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    We present an application of the discontinuous Galerkin (DG) method to regional wave propagation. The method makes use of unstructured tetrahedral meshes, combined with a time integration scheme solving the arbitrary high-order derivative (ADER) Riemann problem. This ADER-DG method is high-order accurate in space and time, beneficial for reliable simulations of high-frequency wavefields over long propagation distances. Due to the ease with which tetrahedral grids can be adapted to complex geometries, undulating topography of the Earth's surface and interior interfaces can be readily implemented in the computational domain. The ADER-DG method is benchmarked for the accurate radiation of elastic waves excited by an explosive and a shear dislocation source. We compare real data measurements with synthetics of the 2009 L'Aquila event (central Italy). We take advantage of the geometrical flexibility of the approach to generate a European model composed of the 3-D <i>EPcrust</i> model, combined with the depth-dependent <i>ak135</i> velocity model in the upper mantle. The results confirm the applicability of the ADER-DG method for regional scale earthquake simulations, which provides an alternative to existing methodologies

    Biclonal gammopathy in a patient taking efalizumab for the treatment of psoriasis

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    We report a patient who developed biclonal gammopathy of undetermined significance during treatment withefalizumab for psoriasis. This plasma cell disorder was found during the evaluation of the patient’s complaint of mild lower extremity paresthesia. The gammopathy spontaneously remitted following cessation of therapy and has not recurred to date. Given the increasing use and development of biological agents for the treatment of psoriasis and other disorders, this finding and the mechanisms by which it may have occurred is of clinical significance
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