50 resultados para COBALT 60


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The present study was undertaken to assess the influence of childhood variables (physical and emotional) to later well-being in a group of rural Swiss (Emmental Cohort). Our study is the first prospective cohort over a time period of more than 50 years. It includes 1537 children who were listed and assessed in 1942 (T1) because they had difficulties in school or were otherwise behaviorally disturbed. In 1995 (T2) more than 60% of the initial population could be reassessed by our study group. We found more subjects at T2 who had been rated as intelligent at T1. More subjects responding to T2 belonged to a higher social class, were more anxious, and had more psychosocial problems at T1. Social income at T2 is correlated to the social class at T1. More subjects have died since who were rated at T1 as being less intelligent, less neurotical, and having higher psychosocial problems. Twice as many men died than women. The emotional situation at T2 is significantly correlated to psychological well-being at T1. The somatic complaints at T2 correlate significantly to neurotic symptoms in childhood (T1). The more intelligent the children were rated at T1, the less emotional and somatic complaints were voiced at T2 and the better the psychic well-being was rated (T2). In addition, the former social milieu (T1) significantly determined somatic and psychological complaints at T2. Our data discern a significant correlation between actual status and former childhood variables more than 50 years later in a rural Swiss cohort (Emmental Cohort).

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Renommierte Wissenschaftler und Praktiker nehmen aus verschiedenen Perspektiven Stellung zu Bedeutung, Positionierung und zukünftiger Ausrichtung der Wirtschaftsinformatik.

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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.