| 1. |
- Outola, I., et al.
(författare)
-
Characterization of the NIST Seaweed Standard Reference Material
- 2006
-
Ingår i: Applied Radiation and Isotopes. - : Elsevier BV. - 0969-8043. ; 64:10-11, s. 1242-1247
-
Tidskriftsartikel (refereegranskat)abstract
- The National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) for seaweed was developed through an interlaboratory comparison with 24 participants from 16 countries. After evaluating different techniques to calculate certified values for the radionuclides, the median method was found to be the most representative technique. The certified values were provided for 13 radionuclides and information values were given for 15 more radionuclides. Results for the natural decay series showed disequilibrium in both the uranium and thorium series. (c) 2006 Elsevier Ltd. All rights reserved.
|
|
| 2. |
|
|
| 3. |
- Jönsson, K. Ingemar, 1959-, et al.
(författare)
-
Radiation tolerance in the eutardigrade Richtersius coronifer
- 2005
-
Ingår i: International Journal of Radiation Biology. - : Taylor & Francis. - 0955-3002 .- 1362-3095. ; 81:9, s. 649-656
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Tardigrades have a reputation of being extremely tolerant to extreme environmental conditions including tolerance to ionizing radiation while in a desiccated, anhydrobiotic state. However, the evidence for radio-tolerance in tardigrades is based on only one previous report, and there is an obvious need for complementary studies. In this paper we report an investigation on radio-tolerance in desiccated and hydrated specimens of the eutardigrade Richtersius coronifer.MATERIALS AND METHODS: Groups of 30 - 50 tardigrades were exposed to gamma-radiation at doses between 1.0 - 9.0 (anhydrobiotic animals) or 0.5 - 5.0 (hydrated animals) kGy and the animals were followed until all were dead. Radiation tolerance of both desiccated and hydrated tardigrades was studied.RESULTS: Both desiccated and hydrated animals irradiated with 0.5 and 1 kGy did not deviate in survival from the control groups. Animals from all exposed groups underwent their moulting and egg production cycle, but at decreasing frequency for doses above 1 kGy. No eggs laid by irradiated animals hatched, while eggs laid by controls did so.CONCLUSION: Our study suggests that radiation tolerance in tardigrades is not due to biochemical protectants connected with the desiccated state. Rather, cryptobiotic tardigrades may rely on efficient mechanisms of DNA repair, the nature of which is currently unknown.
|
|
| 4. |
|
|
| 5. |
- Jönsson, Ingemar, et al.
(författare)
-
Radiation tolerance in the eutardigrade Richtersius coronifer
- 2005
-
Ingår i: International Journal of Radiation Biology. - : Informa UK Limited. - 0955-3002 .- 1362-3095. ; 81:9, s. 649-656
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: Tardigrades have a reputation of being extremely tolerant to extreme environmental conditions including tolerance to ionizing radiation while in a desiccated, anhydrobiotic state. However, the evidence for radio-tolerance in tardigrades is based on only one previous report, and there is an obvious need for complementary studies. In this paper we report an investigation on radio-tolerance in desiccated and hydrated specimens of the eutardigrade Richtersius coronifer . Materials and methods: Groups of 30 – 50 tardigrades were exposed to γ-radiation at doses between 1.0 – 9.0 (anhydrobiotic animals) or 0.5 – 5.0 (hydrated animals) kGy and the animals were followed until all were dead. Radiation tolerance of both desiccated and hydrated tardigrades was studied. Results: Both desiccated and hydrated animals irradiated with 0.5 and 1 kGy did not deviate in survival from the control groups. Animals from all exposed groups underwent their moulting and egg production cycle, but at decreasing frequency for doses above 1 kGy. No eggs laid by irradiated animals hatched, while eggs laid by controls did so. Conclusion: Our study suggests that radiation tolerance in tardigrades is not due to biochemical protectants connected with the desiccated state. Rather, cryptobiotic tardigrades may rely on efficient mechanisms of DNA repair, the nature of which is currently unknown.
|
|
| 6. |
- Moorman, AV, et al.
(författare)
-
No prognostic effect of additional chromosomal abnormalities in children with acute lymphoblastic leukemia and 11q23 abnormalities
- 2005
-
Ingår i: Leukemia. - London : Nature Publishing Group. - 0887-6924 .- 1476-5551. ; 19:4, s. 557-563
-
Tidskriftsartikel (refereegranskat)abstract
- This study characterized the additional chromosomal abnormalities (ACA) associated with 11q23 rearrangements in 450 infants and children with acute lymphoblastic leukemia ( ALL) and examined the impact of these ACA on survival. Overall, 213 (47%) cases had ACA but the incidence varied according to patient age and 11q23 subgroup. Infants and patients with t(4; 11)(q21; q23) had the lowest incidence of ACA (50/182 (27%) and 57/216 (26%) respectively), whereas patients with del( 11)( q23) had the highest incidence (66/93 (71%)). Del( 11)( q23) abnormalities were heterogeneous and occasionally secondary to t( 9; 22)(q34; q11.2). Thus, patients with del( 11)( q23) comprised a separate biological entity, which was clearly distinct from those with an 11q23 translocation. The most frequent specific ACA were trisomy X ( n = 38), abnormal 12p ( n = 32), abnormal 9p ( n = 28) and del( 6q) ( n = 19). The presence of ACA did not change the 5 year event-free survival estimates among children (56% (95% CI 46 - 65%) vs 62% (54 - 69%)) or infants (22% ( 15 - 29%) vs 18% ( 9 - 29%)), nor when the different 11q23 subgroups were analyzed separately. This study has conclusively demonstrated that there is no prognostic effect of secondary chromosomal changes in association with 11q23 abnormalities in childhood ALL. However, characterization of these ACA is important to determine their potential role in initiation of MLL driven leukemogenesis.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
