@article{SchumannEberleinMuhtadietal.2018, author = {Schumann, Sarah and Eberlein, Uta and Muhtadi, Razan and Lassmann, Michael and Scherthan, Harry}, title = {DNA damage in leukocytes after internal ex-vivo irradiation of blood with the α-emitter Ra-223}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, number = {2286}, doi = {10.1038/s41598-018-20364-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-175596}, year = {2018}, abstract = {Irradiation with high linear energy transfer α-emitters, like the clinically used Ra-223 dichloride, severely damages cells and induces complex DNA damage including closely spaced double-strand breaks (DSBs). As the hematopoietic system is an organ-at-risk for the treatment, knowledge about Ra-223-induced DNA damage in blood leukocytes is highly desirable. Therefore, 36 blood samples from six healthy volunteers were exposed ex-vivo (in solution) to different concentrations of Ra-223. Absorbed doses to the blood were calculated assuming local energy deposition of all α- and β-particles of the decay, ranging from 0 to 142 mGy. γ-H2AX + 53BP1 co-staining and analysis was performed in leukocytes isolated from the irradiated blood samples. For DNA damage quantification, leukocyte samples were screened for occurrence of α-induced DNA damage tracks and small γ-H2AX + 53BP1 DSB foci. This revealed a linear relationship between the frequency of α-induced γ-H2AX damage tracks and the absorbed dose to the blood, while the frequency of small γ-H2AX + 53BP1 DSB foci indicative of β-irradiation was similar to baseline values, being in agreement with a negligible β-contribution (3.7\%) to the total absorbed dose to the blood. Our calibration curve will contribute to the biodosimetry of Ra-223-treated patients and early after incorporation of α-emitters.}, language = {en} } @article{RomoliChakrabortyDorneretal.2018, author = {Romoli, Carlo and Chakraborty, Nachiketa and Dorner, Daniela and Taylor, Andrew and Blank, Michael}, title = {Flux Distribution of Gamma-Ray Emission in Blazars: The Example of Mrk 501}, series = {Galaxies}, volume = {6}, journal = {Galaxies}, number = {4}, organization = {FACT and H.E.S.S. Collaborations}, issn = {2075-4434}, doi = {10.3390/galaxies6040135}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-197580}, year = {2018}, abstract = {Flux distribution is an important tool to understand the variability processes in activegalactic nuclei. We now have available a great deal of observational evidences pointing towards thepresence of log-normal components in the high energy light curves, and different models have beenproposed to explain these data. Here, we collect some of the recent developments on this topic usingthe well-known blazar Mrk 501 as example of complex and interesting aspects coming from its fluxdistribution in different energy ranges and at different timescales. The observational data we refer toare those collected in a complementary manner by Fermi-LAT over multiple years, and by the FirstG-APD Cherenkov Telescope (FACT) telescope and the H.E.S.S. array in correspondence of the brightflare of June 2014}, language = {en} }