997 resultados para COBALT 60


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A 192-day experiment involving 144 young Angus steers fed growing and finishing diets containing 20% corn gluten feed was conducted to evaluate feeding a soluble source of readily available cobalt. No benefits were observed in rate of gain, feed intake or carcass value by feeding the available source of cobalt.

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The outcome of spinal surgery in dogs with absent voluntary motor function and nociception following intervertebral disc (IVD) herniation is highly variable, which likely attests to differences in the severity of spinal cord damage. This retrospective study evaluated the extent to which neurological signs correlated with histologically detected spinal cord damage in 60 dogs that were euthanased because of thoracolumbar IVD herniation. Clinical neurological grades correlated significantly with the extent of white matter damage (P<0.001). However, loss of nociception also occurred in 6/31 (19%) dogs with relatively mild histological changes. The duration of clinical signs, Schiff-Sherrington posture, loss of reflexes and pain on spinal palpation were not significantly associated with the severity of spinal cord damage. Although clinical-pathological correlation was generally good, some clinical signs frequently thought to indicate severe cord injury did not always correlate with the degree of cord damage, suggesting functional rather than structural impairment in some cases.

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Rigid electron donor-acceptor conjugates (1-3) that combine -extended benzodifurans as electron donors and C-60 molecules as electron acceptors with different linkers have been synthesized and investigated with respect to intramolecular charge-transfer events. Electrochemistry, fluorescence, and transient absorption measurements revealed tunable and structure-dependent charge-transfer processes in the ground and excited states. Our experimental findings are underpinned by density-functional theory calculations.

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The migration of radioactive and chemical contaminants in clay materials and argillaceous host rocks is characterised by diffusion and retention processes. Valuable information on such processes can be gained by combining diffusion studies at laboratory scale with field migration tests. In this work, the outcome of a multi-tracer in situ migration test performed in the Opalinus Clay formation in the Mont Terri underground rock laboratory (Switzerland) is presented. Thus, 1.16 x 10(5) Bq/L of HTO, 3.96 x 10(3) Bq/L of Sr-85, 6.29 x 10(2) Bq/L of Co-60, 2.01 x 10(-3) mol/L Cs, 9.10 x 10(-4) mol/L I and 1.04 x 10(-3) mol/L Br were injected into the borehole. The decrease of the radioisotope concentrations in the borehole was monitored using in situ gamma-spectrometry. The other tracers were analyzed with state-of-the-art laboratory procedures after sampling of small water aliquots from the reservoir. The diffusion experiment was carried out over a period of one year after which the interval section was overcored and analyzed. Based on the experimental data from the tracer evolution in the borehole and the tracer profiles in the rock, the diffusion of tracers was modelled with the numerical code CRUNCH. The results obtained for HTO (H-3), I- and Br- confirm previous lab and in situ diffusion data. Anionic fluxes into the formation were smaller compared to HTO because of anion exclusion effects. The migration of the cations Sr-85(2+), Cs+ and Co-60(2+) was found to be governed by both diffusion and sorption processes. For Sr-85(2+), the slightly higher diffusivity relative to HTO and the low sorption value are consistent with laboratory diffusion measurements on small-scale samples. In the case of Cs+, the numerically deduced high diffusivity and the Freundlich-type sorption behaviour is also supported by ongoing laboratory data. For Co, no laboratory diffusion data were yet available for comparison; however, the modelled data suggests that Co-60(2+) sorption was weaker than would be expected from available batch sorption data. Overall, the results demonstrate the feasibility of the experimental setup for obtaining high-quality diffusion data for conservative and sorbing tracers. (C) 2007 Elsevier Ltd. All rights reserved.

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The Indo-Pacific warm pool houses the largest zone of deep atmospheric convection on Earth and plays a critical role in global climate variations. Despite the region’s importance, changes in Indo-Pacific hydroclimate on orbital timescales remain poorly constrained. Here we present high-resolution geochemical records of surface runoff and vegetation from sediment cores fromLake Towuti, on the island of Sulawesi in central Indonesia, that continuously span the past 60,000 y.We show that wet conditions and rainforest ecosystems on Sulawesi present during marine isotope stage 3 (MIS3) and the Holocene were interrupted by severe drying between ∼33,000 and 16,000 y B.P. when Northern Hemisphere ice sheets expanded and global temperatures cooled. Our record reveals little direct influence of precessional orbital forcing on regional climate, and the similarity between MIS3 and Holocene climates observed in Lake Towuti suggests that exposure of the Sunda Shelf has a weaker influence on regional hydroclimate and terrestrial ecosystems than suggested previously. We infer that hydrological variability in this part of Indonesia varies strongly in response to high-latitude climate forcing, likely through reorganizations of the monsoons and the position of the intertropical convergence zone. These findings suggest an important role for the tropical western Pacific in amplifying glacial–interglacial climate variability.

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n einer Festschrift für Helmut Schlichtherle, der die Pfahlbauforschung in Deutschland ganz wesentlich mitgeprägt hat, berichten 50 seiner Fachkollegen aus Frankreich, der Schweiz, Deutschland und Slowenien über aktuelle Ergebnisse der Siedlungsarchäologie. Die Beiträge befassen sich in erster Linie mit der Vernetzung von Siedlungen und deren ökonomischen Grundlagen, aber auch mit der Herstellung und sozialen Funktion von herausragenden Artefakten. Thematisiert wird auch die Frage nach den Anfängen hierarchischer Siedlungssysteme. Der zeitliche Rahmen erstreckt sich von den frühesten Bauernkulturen bis zur Völkerwanderungszeit. Mit dem Buch wird für die Siedlungsarchäologie ein Werk vorgelegt, das sowohl neue Erkenntnisse vorbringt als auch Perspektiven für die zukünftige Forschung aufzeigt. Es wird in den Fachbibliotheken der Universitäten, Denkmalämter und Museen unverzichtbar sein .

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The preferred type of post-remission therapy (PRT) in patients with acute myeloid leukemia (AML) in first complete remission (CR1) is a subject of continued debate, especially in patients at higher risk of nonrelapse mortality (NRM), including patients >40 years of age. We report results of a time-dependent multivariable analysis of allogenic hematopoietic stem cell transplantation (alloHSCT) (n=337) versus chemotherapy (n=271) or autologous HSCT (autoHSCT) (n=152) in 760 patients aged 40-60 years with AML in CR1. Patients receiving alloHSCT showed improved overall survival (OS) as compared with chemotherapy (respectively, 57±3% vs 40±3% at 5 years, P<0.001). Comparable OS was observed following alloHSCT and autoHSCT in patients with intermediate-risk AML (60±4 vs 54±5%). However, alloHSCT was associated with less relapse (hazard ratio (HR) 0.51, P<0.001) and better relapse-free survival (RFS) (HR 0.74, P=0.029) as compared with autoHSCT in intermediate-risk AMLs. AlloHSCT was applied following myeloablative conditioning (n=157) or reduced intensity conditioning (n=180), resulting in less NRM, but comparable outcome with respect to OS, RFS and relapse. Collectively, these results show that alloHSCT is to be preferred over chemotherapy as PRT in patients with intermediate- and poor-risk AML aged 40-60 years, whereas autoHSCT remains a treatment option to be considered in patients with intermediate-risk AML.Leukemia advance online publication, 23 December 2014; doi:10.1038/leu.2014.332.

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