National Repository of Grey Literature 43 records found  beginprevious42 - 43  jump to record: Search took 0.01 seconds. 
Adipokinetic hormone counteracts oxidative stress elicited in insects by hydrogen peroxide: in vivo and in vitro study
BEDNÁŘOVÁ, Andrea
The involvement of members of Adipokinetic hormone (AKH) family in regulation of response to oxidative stress (OS) was investigated in the present study. OS was elicited in the insect body by exogenous application of hydrogen peroxide. In vivo experiments reveal that injection of hydrogen peroxide into the haemocoel of the firebug, Pyrrhocoris apterus, increases the level of AKH in the central nervous system (CNS) and in the haemolymph. The injection of hydrogen peroxide also increases the mortality of experimental bugs, whereas co-injection of hydrogen peroxide with Pyrap-AKH reduces mortality to control levels. Importantly, an increase in haemolymph protein carbonyl (an OS biomarker) levels is decreased to control levels when hydrogen peroxide is co-injected with Pyrap-AKH. Similar results were obtained using in vitro experiments. OS biomarkers such as malondialdehyde and protein carbonyls were significantly enhanced upon exposure of isolated CNS to hydrogen peroxide in vitro, whereas co-treatment of the CNS with hydrogen peroxide and Pyrap-AKH reduces their level significantly. Catalase activity was measured as well and the same pattern was observed. The results of the present study provide strong support on the feedback regulation between oxidative stressors and AKH action, and implicate AKH in counteracting OS.
Is it Possible by Thermodynamic Equilibrium Calculations to Judge the Presumable Reaction Mechanism?
Pekárek, Vladimír ; Bureš, M.
In a laboratory model system consisting of fly ash from MWI, copper and sodium chloride and activated carbon in N2 + SO2 atmosphere and at 340oC, the de novo synthetic reactions of formation of PCDD/Fs were studied under laboratory conditions in the presence of sulfur dioxide, hydrogen peroxide, and sulfuric acid. On the basis of experimental results and thermodynamic calculations, the following mechanisms are proposed and discussed: oxidative destruction, conversion of cupric chloride to sulfate, and catalyzed Deacon reaction.

National Repository of Grey Literature : 43 records found   beginprevious42 - 43  jump to record:
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