m-FISH analysis reveals complexity of chromosome aberrations in individuals occupationally exposed with internal plutonium: A pilot study to assess the relevance of complex aberrations as biomarkers of exposure to high-LET α particles

We recently demonstrated that a significant proportion of apparently stable insertions induced after exposure to a mean of 1 α particle/cell, detected using 3-colour FISH, were part of larger unstable complexes when visualised by 24-colour FISH. Interestingly, regardless of the long-term persistence capability of the cell, the complexity of each α particle-induced complex appeared to be specific to the nuclear traversal of a single -particle. To assess whether aberrations of a similar complexity are observed in vivo and also to examine the usefulness of detecting such aberrations as a biomarker of chronic exposure to α particles, we have carried out a limited pilot study of Russian workers with large body burdens of -particle emitting plutonium (Pu). We found unstable cells containing non-transmissible complex aberrations in all of the Pu exposed subjects analysed by m-FISH. In addition, all of the complexes seen were consistent with those previously observed in vitro. Non-transmissible complex aberrations were more common than transmissible-type complexes, consistent with on-going/chronic exposure and insertions were dominant features of both type of complex. Accordingly, this preliminary study supports the proposal that aberration complexity and non-transmissibility are the major cytogenetic features of α particle exposure that could potentially be exploited as a specific indicator of chronic exposures to high-LET α particles

New features of the low temperature ductile shear failure observed in bulk amorphous alloys

Fractographic studies of ductile shear failure under the uniaxial compression for rod-like samples of the Zr(41.2)Ti(13.8)Ni(10)Cu(12.5)Be(22.5) and Cu(50)Zr(35)Ti(8)Hf(5)Ni(2) bulk amorphous alloys at temperatures 300 and 77 K are presented. The mechanisms of shear deformation and failure appeared to have characteristics in common with other amorphous alloys prepared in the form of thin ribbons. However, there were a number of new fractographic features observed due to the bulk character of the samples and to the large supercooled liquid region of these alloys. (C) 2000 Kluwer Academic Publishers

Low temperature ductile shear failure of Zr41.2Ti13.8Ni10Cu12.5Be22.5 and Cu50Zr35Ti8Hf5Ni2 bulk amorphous alloys

Fractographic study of ductile shear failure under uniaxial compression of rod-like samples of the Zr41.2Ti13.8Ni10Cu12.5Be22.5 and Cu50Zr35Ti8Hf5Ni2 bulk amorphous alloys at temperatures of 300 and 77 K is presented. Although the mechanisms of shear deformation and fracture appeared the same as in conventional amorphous alloys prepared in form of thin ribbons, some new fractographic features are observed, owing to the bulk character of the samples and also due to the large supercooled liquid region of these alloys.</p

Low temperature ductile shear failure of Zr41.2Ti13.8Ni10Cu12.5Be22.5 and Cu50Zr35Ti8Hf5Ni2 bulk amorphous alloys

Fractographic study of ductile shear failure under uniaxial compression of rod-like samples of the Zr41.2Ti13.8Ni10Cu12.5Be22.5 and Cu50Zr35Ti8Hf5Ni2 bulk amorphous alloys at temperatures of 300 and 77 K is presented. Although the mechanisms of shear deformation and fracture appeared the same as in conventional amorphous alloys prepared in form of thin ribbons, some new fractographic features are observed, owing to the bulk character of the samples and also due to the large supercooled liquid region of these alloys