Zum kohlenstoffaustausch zwischen stabilisierten austenitischen stählen und flüssigem natrium

We have measured the carbon-concentration profiles in the surface zones of specimens of stabilized austenitic steels after exposure to liquid sodium of 700°C in a sodium circuit. Under the conditions of the tests the specimens were carburized. However, the carbon content of the ferritic corrosion layers decreased to values the initial values. They corresponded to the carbon activity of the sodium.     

Untersuchung von Korrosions- und Abscheidungsphänomenen an ausgewählten Komponenten eines Natriumkreislaufs

Evaluation of corrosion and deposition phenomena of selected components of a sodium loop The test vessels and heat exchangers of a sodium high temperature loop, which have been exposed to the flowing sodium up to 973 K and flow velocities up to 5 m/s, were examined in respect to long term corrosion effects as well as to deposition effects as well as to deposition effects. In addition to morphologic and metallographic techniques mainly chemical-analytical methods were applied to estimate concentration gradients. The stabilized austenitic steel X 8 CrNiMoNb 16 13 fulfills the demands of high-temperature application in sodium.     

Relevance of hair and spines of the European hedgehog (Erinaceus europaeus) as biomonitoring tissues for arsenic and metals in relation to blood

Hair has been proven to be suitable for non-destructive and non-invasive exposure assessments in human and mammal populations. A previous study with European hedgehog (Erinaceus europaeus) showed that, for some metals, hair and spine metal concentrations were positively correlated to levels in liver, kidney and muscle. Although blood has been studied in a wide variety of species, the relationship between hair and blood metal concentrations has yet to be quantified in many mammalian species. Tissue concentrations from hedgehogs residing in a park with known metal pollution were compared with those from a reference park and correlations between contaminant levels in hair and blood, and spines and blood were studied. Moreover, the relative distribution of arsenic and metals in hair, spines and blood was determined. Elevated concentrations were found in hedgehogs residing in the polluted site for As (8.2 μg/g, 6.3 μg/g, 3.6 μg/ml), Cd (0.48 μg/g, 0.17 μg/g, 0.02 μg/ml) and Pb (7.6 μg/g, 7.3 μg/g, 54 μg/ml), in hair, spines and blood respectively. Positive correlations were identified for exposure levels between hair and blood as well as between spines and blood for three elements (As, Cd, and Pb), whereas a negative correlation was found between Cr concentrations in spines and blood. In conclusion, hair and spines can be used to monitor blood concentrations of some metals, although more data are needed on uptake from the food chain and on the incorporation dynamics of these contaminants.     

TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) Is Upregulated in Lymphocytes Stimulated with Concanavalin A

The glycolytic modulator TP53-Inducible Glycolysis and Apoptosis Regulator (TIGAR) is overexpressed in several types of cancer and has a role in metabolic rewiring during tumor development. However, little is known about the role of this enzyme in proliferative tissues under physiological conditions. In the current work, we analysed the role of TIGAR in primary human lymphocytes stimulated with the mitotic agent Concanavalin A (ConA). We found that TIGAR expression was induced in stimulated lymphocytes through the PI3K/AKT pathway, since Akti-1/2 and LY294002 inhibitors prevented the upregulation of TIGAR in response to ConA. In addition, suppression of TIGAR expression by siRNA decreased the levels of the proliferative marker PCNA and increased cellular ROS levels. In this model, TIGAR was found to support the activity of glucose 6-phosphate dehydrogenase (G6PDH), the first enzyme of the pentose phosphate pathway (PPP), since the inhibition of TIGAR reduced G6PDH activity and increased autophagy. In conclusion, we demonstrate here that TIGAR is upregulated in stimulated human lymphocytes through the PI3K/AKT signaling pathway, which contributes to the redirection of the carbon flux to the PPP.