Authors:Ana Neacsu, I. Contineanu, V. Popa and M. Contineanu
Dehydration of irradiated and non-irradiated asparagine monohydrate was investigated by means of a computer interfaced PerkinElmer
1B DSC in isothermal conditions and static atmosphere. Isothermal runs were performed at 358, 363, 368 and 373 K. Samples
were γ-irradiated at room temperature, using a 137Cs source with an activity of 3·1013 Bq and a dose rate of 4·102 Gy h−1, with irradiation times between 8–116 h. Isothermal kinetics were analyzed via the common factorized rate equation. Šesták-Berggren
conversion function was found to best fit the experimental data. Of the three fitting parameters, only the one associated
with the activation energy was found to follow a coherent variation with the exposure time. Even within this simple model,
that makes the activation energy a useful stability criterion within a set of similar samples.
Authors:K. Alloun, O. Benchabane, M. Hazzit, F. Mouhouche, A. Baaliouamer, A. Chikhoune and A. Benchabane
treatment among them is processing with ionizing radiation [ 6 ]. The ionizing radiations originated from gamma rays are produced by radioactive substances (radioisotopes). The approved sources of gamma rays for food irradiation are the radionuclides cobalt
Authors:Monica Nemtanu, Mirela Brasoveanu, Viorica Meltzer, Elena Pincu and C. Oproiu
The purpose of the present work deals with the evaluation of the electron beam irradiation effects on some natural products
based on thermal analysis. Some natural products with therapeutic contributions (artichoke, sea buckthorn, common sage, stonebreaker
and cloves) were irradiated with doses up to 9 kGy using accelerated electron beam. The thermal profiles lead to identify
three phenomena: dehydration — volatilization, irreversible degradation — molecular reorganization and residue decomposition.
The radio-induced degradations determine slight shifts of the temperatures where these phenomena occur. The energetic value
of the studied products is affected by e-beam treatment depending on irradiation dose.
Authors:A Todorović, A Todorović, A Todorović, S Pejić, S Pejić, S Pejić, J Kasapović, J Kasapović, J Kasapović, V Stojiljković, V Stojiljković, V Stojiljković, SB Pajović, SB Pajović, SB Pajović, DT Kanazir, DT Kanazir and DT Kanazir
In order to examine
in activity and inducibility of
antioxidative enzymes in rat cerebral cortex and hippocampus are underlying
their different sensitivity to radiation, we exposed four-day-old female
Wistar rats to cranial radiation of 3 Gy of g-rays. After isolation
of hippocampus and cortex 1 h or 24 h following exposure, activities of
copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase
(MnSOD) and catalase (CAT) were measured and
compared to unirradiated controls. MnSOD protein levels were determined by SDS-PAGE
electrophoresis and Western blot analysis. Our results showed that CuZnSOD activity in hippocampus and cortex
was significantly decreased 1 h and 24 h after irradiation with 3 Gy of g-rays. MnSOD activity in both brain regions was also
decreased 1 h after irradiation. 24 h following exposure, manganese SOD
activity in hippocampus almost achieved control values, while in cortex it
significantly exceeded the activity of the relevant controls. CAT activity in
hippocampus and cortex remained stable 1 h, as well as 24 h after irradiation
with 3 Gy of g-rays.
MnSOD protein level in hippocampus and cortex decreased 1 h after irradiation
with 3 Gy of g-rays. 24 h after exposure, MnSOD protein level in cortex
was similar to control values, while in hippocampus it was still
significantly decreased. We have
concluded that regional differences in MnSOD radioinducibility are regulated
at the level of protein synthesis, and that they represent one of the main
reasons for region-specific radiosensitivity of the brain.
Bagi, G., Bornemisza-Pauspertl, P., Hidvegi, E. J. (1988): Inverse correlation between growth and degrading enzyme activity of seedlings after gamma and neutron irradiation of pea seeds.
Int. J. Radiat. Biol