277 research outputs found

    Electron-Microscopy Investigations of the Warping Effect in Pigmented High Density Polyethylene

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    The warping effect of high-density polyethylene (HDPE) articles produced by organic pigmentation has been studied by scanning electron microscopy. A warping pigment and its warp-free analogue obtained by surface treatment have been observed and compared to an inorganic warp-free pigment. The results indicate that the generally accepted nucleation theory is not sufficient to describe fully the warping effect. An attempt is made to describe this effect in terms of pigment-polymer compatibility

    Spin-resolved electronic response to the phase transition in MoTe2_2

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    The semimetal MoTe2_2 is studied by spin- and angle- resolved photoemission spectroscopy to probe the detailed electronic structure underlying its broad range of response behavior. A novel spin-texture is uncovered in the bulk Fermi surface of the non-centrosymmetric structural phase that is consistent with first-principles calculations. The spin-texture is three-dimensional, both in terms of momentum dependence and spin-orientation, and is not completely suppressed above the centrosymmetry-breaking transition temperature. Two types of surface Fermi arc are found to persist well above the transition temperature. The appearance of a large Fermi arc depends strongly on thermal history, and the electron quasiparticle lifetimes are greatly enhanced in the initial cooling. The results indicate that polar instability with strong electron-lattice interactions exists near the surface when the bulk is largely in a centrosymmetric phase

    Group size planning for breedings of gene-modified mice and other organisms following Mendelian inheritance

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    Colony management of gene-modified animals is time-consuming, costly and affected by random events related to Mendelian genetics, fertility and litter size. Careful planning is mandatory to ensure successful outcomes using the least number of animals, hence adhering to the 3R principles of animal welfare. Here we have developed an R package, accessible also through an interactive public website, that optimizes breeding design by providing information about the optimal number of breedings needed to obtain defined breeding outcomes, taking into account specific species, strain, or line properties and success probability. Our software also enables breeding planning for balanced male-to-female ratio or single-sex experiments. We show that, for single-sex designs, the necessary number of breedings is at least doubled compared to the use of all born animals. While the presented tool provides preset parameters for the laboratory mouse, it can be readily used for any other species

    Peroxiredoxin 6 is required for blood vessel integrity in wounded skin

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    Peroxiredoxin 6 (Prdx6) is a cytoprotective enzyme with largely unknown in vivo functions. Here, we use Prdx6 knockout mice to determine its role in UV protection and wound healing. UV-mediated keratinocyte apoptosis is enhanced in Prdx6-deficient mice. Upon skin injury, we observe a severe hemorrhage in the granulation tissue of knockout animals, which correlates with the extent of oxidative stress. At the ultrastructural level endothelial cells appear highly damaged, and their rate of apoptosis is enhanced. Knock-down of Prdx6 in cultured endothelial cells also increases their susceptibility to oxidative stress, thus confirming the sensitivity of this cell type to loss of Prdx6. Wound healing studies in bone marrow chimeric mice demonstrate that Prdx6-deficient inflammatory and endothelial cells contribute to the hemorrhage phenotype. These results provide insight into the cross-talk between hematopoietic and resident cells at the wound site and the role of reactive oxygen species in this interplay

    Prospective monitoring of cefepime in intensive care unit adult patients

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    INTRODUCTION: Cefepime has been associated with a greater risk of mortality than other beta-lactams in patients treated for severe sepsis. Hypotheses for this failure include possible hidden side-effects (for example, neurological) or inappropriate pharmacokinetic/pharmacodynamic (PK/PD) parameters for bacteria with cefepime minimal inhibitory concentrations (MIC) at the highest limits of susceptibility (8 mg/l) or intermediate-resistance (16 mg/l) for pathogens such as Enterobacteriaceae, Pseudomonas aeruginosa and Staphylococcus aureus. We examined these issues in a prospective non-interventional study of 21 consecutive intensive care unit (ICU) adult patients treated with cefepime for nosocomial pneumonia. METHODS: Patients (median age 55.1 years, range 21.8 to 81.2) received intravenous cefepime at 2 g every 12 hours for creatinine clearance (CLCr) >or= 50 ml/min, and 2 g every 24 hours or 36 hours for CLCr < 50 ml/minute. Cefepime plasma concentrations were determined at several time-points before and after drug administration by high-pressure liquid chromatography. PK/PD parameters were computed by standard non-compartmental analysis. RESULTS: Seventeen first-doses and 11 steady states (that is, four to six days after the first dose) were measured. Plasma levels varied greatly between individuals, from two- to three-fold at peak-concentrations to up to 40-fold at trough-concentrations. Nineteen out of 21 (90%) patients had PK/PD parameters comparable to literature values. Twenty-one of 21 (100%) patients had appropriate duration of cefepime concentrations above the MIC (T>MIC >or= 50%) for the pathogens recovered in this study (MIC <or= 4 mg/l), but only 45 to 65% of them had appropriate coverage for potential pathogens with cefepime MIC >or= 8 mg/l. Moreover, 2/21 (10%) patients with renal impairment (CLCr < 30 ml/minute) demonstrated accumulation of cefepime in the plasma (trough concentrations of 20 to 30 mg/l) in spite of dosage adjustment. Both had symptoms compatible with non-convulsive epilepsy (confusion and muscle jerks) that were not attributed to cefepime-toxicity until plasma levels were disclosed to the caretakers and symptoms resolved promptly after drug arrest. CONCLUSIONS: These empirical results confirm the suspected risks of hidden side-effects and inappropriate PK/PD parameters (for pathogens with upper-limit MICs) in a population of ICU adult patients. Moreover, it identifies a safety and efficacy window for cefepime doses of 2 g every 12 hours in patients with a CLCr >or= 50 ml/minute infected by pathogens with cefepime MICs <or= 4 mg/l. On the other hand, prompt monitoring of cefepime plasma levels should be considered in case of lower CLCr or greater MICs

    L'APPLICATION DU PRINCIPE DE LAÏCITE A LA JUSTICE

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    Ce rapport sur « l’application de la laïcité à la justice » est le fruit d’un travail collectif mené sur deux années par une équipe d’enseignants-chercheurs (juristes et sociologues) avec le soutien de la mission de recherche « Droit et Justice ».Le sujet est d’autant plus intéressant que la justice n’est sans doute pas un service public comme les autres. Outre une laïcisation plus lente, la justice se distingue également des autres services publics par la diversité des acteurs qui s’y croisent : tous ne sont pas des professionnels (les jurés notamment) et parmi les professionnels, tous ne sont pas des agents publics. Toutes ces personnes ne sont donc pas soumises aux mêmes règles.L’essentiel de la recherche a consisté à voir si le droit positif mettait à la charge de tous les acteurs de la justice une obligation de laïcité et de neutralité religieuse, et le cas échéant selon la même intensité. Parmi ceux-ci, certains acteurs sont par ailleurs amenés à trancher des questions d’ordre religieux susceptibles de les placer sur un terrain qui ne leur est pas familier.Ils ne peuvent pas s’abriter derrière leur neutralité pour ne pas répondre à la question soulevée par ces litiges. La recherche s’est donc portée également sur la manière dont les juges mettenten œuvre leur neutralité dans leur compréhension et leur traitement ou leur qualification du fait religieux.Pour répondre à ces questions, une étude du droit positif complétée par des entretiens auprès des professionnels concernés a été privilégiée

    What the literature tells us about score sheet design

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    Score sheets are an essential tool of animal welfare. They allow transparent assessments to be made of animal health and behavior during animal experiments and they define interventions when deviations from normal status are detected. As such, score sheets help to refine animal experiments as part of the 3R (replacement, reduction and refinement) concept. This mini review aims at summarizing the scarce literature available on score sheet design

    All-metallic magnetic Purcell enhancement in a thermally stable room-temperature maser

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    <p>This contains the experimental raw data:</p><ul><li>Model_SRRcluster.stl<ul><li>the 3D model of the clustered SRR<br> </li></ul></li><li>01_SRRcluster_ThersholdExperiment_RawData<ul><li>1,300 maser pulses recorded by oscilloscope along with gradually increased laser excitation energy</li><li>corresponding laser excitation energy</li><li>S11 parameter of the resonator measured using vector network analyzer (VNA)<br> </li></ul></li><li>02_SRRcluster_ThermalStabilityExperiment_RawData<ul><li>18,000 maser pulses recorded by oscilloscope:</li><li>corresponding laser excitation energy</li><li>S11 parameters of the resonator before and after the masing experiment, measured using vector network analyzer (VNA)<br> </li></ul></li><li>03_SrTiO3_ThermalStabilityExperiment_RawData<ul><li>12,000 maser pulses recorded by oscilloscope:</li><li>corresponding laser excitation energy</li><li>S11 parameters of the resonator before and after the masing experiment, measured using vector network analyzer (VNA)</li></ul></li></ul><p> </p&gt
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