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Here, we highlight the potential translational benefits of delivering FLASH radiotherapy using ultra-high dose rates (>100 Gy·s−1). Compared with conventional dose-rate (CONV; 0.07–0.1 Gy·s−1) modalities, we showed that FLASH did not cause radiation-induced deficits in learning and memory in mice. Moreover, 6 months after exposure, CONV caused permanent alterations in neurocognitive end points, whereas FLASH did not induce behaviors characteristic of anxiety and depression and did not impair extinction memory. Mechanistic investigations showed that increasing the oxygen tension in the brain through carbogen breathing reversed the neuroprotective effects of FLASH, while radiochemical studies confirmed that FLASH produced lower levels of the toxic reactive oxygen species hydrogen peroxide. In addition, FLASH did not induce neuroinflammation, a process described as oxidative stress-dependent, and was also associated with a marked preservation of neuronal morphology and dendritic spine density. The remarkable normal tissue sparing afforded by FLASH may someday provide heretofore unrealized opportunities for dose escalation to the tumor bed, capabilities that promise to hasten the translation of this groundbreaking irradiation modality into clinical practice.

210 Po is a radioactive component of conventional cigarette tobacco smoke and is a recognized carcinogen. Despite the expanding market of heated tobacco products, no data are available on the activity of 210 Po in the smoke of IQOS Heets cigarette. We determined the 210 Po activity in the mainstream smoke of thirteen cigarette brands available on the Swiss market using a smoking machine and compared the results to the 210 Po activity measured in the mainstream smoke of the IQOS system. In addition, we measured the 210 Po and 210 Pb loss on heating after uniform heating from 50 to 600 °C for several cigarette brands and the Heets cigarettes. 13.6 ± 4.1% of 210 Po activity was found in the mainstream smoke in conventional cigarette smoking (7% for 210 Pb). This dropped to 1.8 ± 0.3% in the mainstream smoke of IQOS Heets. Conversely, when the tobacco was heated uniformly at 330 °C, a loss of 210 Po of more than 80% was observed for all type of cigarettes. Apparently, IQOS significantly reduced the 210 Po and 210 Pb activities in the mainstream smoke. However, our results show that only 15% of the Heets tobacco reaches 330 °C with IQOS. While IQOS reduces the 210 Po and 210 Pb activities in the mainstream smoke compared to conventional cigarettes, it only heats a marginal fraction of the tobacco present in the Heets cigarette. Because smoking is an addiction (mostly due to nicotine), IQOS could possibly deliver an unsatisfactory dose of nicotine to a Heets cigarette smoker, as most of the tobacco is left unaltered.

Background: Occupational risks, the present nuclear threat, and the potential danger associated with nuclear power have raised concerns regarding the metabolism of plutonium in pregnant women. Objective: We measured plutonium levels in the milk teeth of children born between 1951 and 1995 to assess the potential risk that plutonium incorporated by pregnant women might pose to the radiosensitive tissues of the fetus through placenta transfer. Methods: We used milk teeth, whose enamel is formed during pregnancy, to investigate the transfer of plutonium from the mother's blood plasma to the fetus. We measured plutonium using sensitive sector field inductively coupled plasma mass spectrometry techniques. We compared our results with those of a previous study on strontium-90 (⁹⁰Sr) released into the atmosphere after nuclear bomb tests. Results: Results show that plutonium activity peaks in the milk teeth of children born about 10 years before the highest recorded levels of plutonium fallout. By contrast, ⁹⁰Sr, which is known to cross the placenta barrier, manifests differently in milk teeth, in accordance with ⁹⁰Sr fallout deposition as a function of time. Conclusions: These findings demonstrate that plutonium found in milk teeth is caused by fallout that was inhaled around the time the milk teeth were shed and not from any accumulation during pregnancy through placenta transfer. Thus, plutonium may not represent a radiologic risk for the radiosensitive tissues of the fetus.

According to biokinetic modelling (see appendix), the measured activities of 210Po of several mBq per sample are compatible with a lethal ingestion of several GBq in 2004. [...]his clinical presentation could not rule out 210Po poisoning. Three scientific teams are currently analysing body, shrine, and earth samples. Because of legal procedures, the date of publication of the detailed results of the exhumation analyses is unknown.

Background and aims Uptake of 90 Sr and 137 Cs in plants varies widely between soil types and between plant species. It is now recognized that the radionuclide uptake in plants is more influenced by site-specific and plant-specific parameters rather than the bulk radionuclide concentration in soil. We hypothesized that the stress which Alpine plants experience because of the short growing season may enhance the phylogenetic effect on the 137 Cs and 90 Sr transfer factors as well as the dependency of the uptake by plant to the concentrations of exchangeable Ca and K of soils. Methods We carried out a field study on the 90 Sr and 137 Cs uptake by 11 species of Alpine plants growing on 6 undisturbed and geochemically different soils in the Alpine valley of Piora, Switzerland. Results Results show that a strong correlation exists between the log TF and the log of exchangeable Ca or K of the soils. Conclusions Cs uptake by Phleum rhaeticum (Poales) and Alchemilla xanthochlora (Rosales) is more sensitive to the amount of exchangeable K in the soil than the corresponding uptake by other orders. Moreover, the 90 Sr results indicate a phylogenetic effect between Non-Eudicot and Eudicots: the order Poales ( Phleum rhaeticum ) concentrating much less 90 Sr than Eudicots do.

Po is a radioactive component of conventional cigarette tobacco smoke and is a recognized carcinogen. Despite the expanding market of heated tobacco products, no data are available on the activity of Po in the smoke of IQOS Heets cigarette. We determined the Po activity in the mainstream smoke of thirteen cigarette brands available on the Swiss market using a smoking machine and compared the results to the Po activity measured in the mainstream smoke of the IQOS system. In addition, we measured the Po and Pb loss on heating after uniform heating from 50 to 600 °C for several cigarette brands and the Heets cigarettes. 13.6 ± 4.1% of Po activity was found in the mainstream smoke in conventional cigarette smoking (7% for Pb). This dropped to 1.8 ± 0.3% in the mainstream smoke of IQOS Heets. Conversely, when the tobacco was heated uniformly at 330 °C, a loss of Po of more than 80% was observed for all type of cigarettes. Apparently, IQOS significantly reduced the Po and Pb activities in the mainstream smoke. However, our results show that only 15% of the Heets tobacco reaches 330 °C with IQOS. While IQOS reduces the Po and Pb activities in the mainstream smoke compared to conventional cigarettes, it only heats a marginal fraction of the tobacco present in the Heets cigarette. Because smoking is an addiction (mostly due to nicotine), IQOS could possibly deliver an unsatisfactory dose of nicotine to a Heets cigarette smoker, as most of the tobacco is left unaltered.

The late president of the Palestinian Authority, Yasser Arafat, died in November 2004 in Percy Hospital, one month after having experienced a sudden onset of symptoms that included severe nausea, vomiting, diarrhoea and abdominal pain and which were followed by multiple organ failure. In spite of numerous investigations performed in France, the pathophysiological mechanisms at the origin of the symptoms could not be identified. In 2011, we found abnormal levels of polonium-210 ((210)Po) in some of Arafat's belongings that were worn during his final hospital stay and which were stained with biological fluids. This finding led to the exhumation of Arafat's remains in 2012. Significantly higher (up to 20 times) activities of (210)Po and lead-210 ((210)Pb) were found in the ribs, iliac crest and sternum specimens compared to reference samples from the literature (p-value <1%). In all specimens from the tomb, (210)Po activity was supported by a similar activity of (210)Pb. Biokinetic calculations demonstrated that a (210)Pb impurity, as identified in a commercial source of 3MBq of (210)Po, may be responsible for the activities measured in Arafat's belongings and remains 8 years after his death. The absence of myelosuppression and hair loss in Mr Arafat's case compared to Mr Litvinenko's, the only known case of malicious poisoning with (210)Po, could be explained by differences in the time delivery-scheme of intake. In conclusion, statistical Bayesian analysis combining all the evidence gathered in our forensic expert report moderately supports the proposition that Mr Arafat was poisoned by (210)Po.

Abstract In legal medicine, the post mortem interval (PMI) of interest covers the last 50 years. When only human skeletal remains are found, determining the PMI currently relies mostly on the experience of the forensic anthropologist, with few techniques available to help. Recently, several radiometric methods have been proposed to reveal PMI. For instance,14 C and90 Sr bomb pulse dating covers the last 60 years and give reliable PMI when teeth or bones are available.232 Th series dating has also been proposed but requires a large amount of bones. In addition,210 Pb dating is promising but is submitted to diagenesis and individual habits like smoking that must be handled carefully. Here we determine PMI on 29 cases of forensic interest using90 Sr bomb pulse. In 12 cases,210 Pb dating was added to narrow the PMI interval. In addition, anthropological investigations were carried out on 15 cases to confront anthropological expertise to the radiometric method. Results show that 10 of the 29 cases can be discarded as having no forensic interest (PMI > 50 years) based only on the90 Sr bomb pulse dating. For 10 other cases, the additional210 Pb dating restricts the PMI uncertainty to a few years. In 15 cases, anthropological investigations corroborate the radiometric PMI. This study also shows that diagenesis and inter-individual difference in radionuclide uptake represent the main sources of uncertainty in the PMI determination using radiometric methods.

In forensic science, there is a strong interest in determining the post-mortem interval (PMI) of human skeletal remains up to 50 years after death. Currently, there are no reliable methods to resolve PMI, the determination of which relies almost exclusively on the experience of the investigating expert. Here we measured ...Sr and ...Pb (...Po) incorporated into bones through a biogenic process as indicators of the time elapsed since death. We hypothesised that the activity of radionuclides incorporated into trabecular bone will more accurately match the activity in the environment and the food chain at the time of death than the activity in cortical bone because of a higher remodelling rate. We found that determining ...Sr can yield reliable PMI estimates as long as a calibration curve exists for ...Sr covering the studied area and the last 50 years. We also found that adding the activity of ...Po, a proxy for naturally occurring ...Pb incorporated through ingestion, to the ...r dating increases the reliability of the PMI value. Our results also show that trabecular bone is subject to both ...Sr and ...Po diagenesis. Accordingly, we used a solubility profile method to determine the biogenic radionuclide only, and we are proposing a new method of bone decontamination to be used prior to ...Sr and ...Pb dating. (ProQuest: ... denotes formulae/symbols omitted.)

In forensic science, there is a strong interest in determining the post-mortem interval (PMI) of human skeletal remains up to 50 years after death. Currently, there are no reliable methods to resolve PMI, the determination of which relies almost exclusively on the experience of the investigating expert. Here we measured 90Sr and 210Pb (210Po) incorporated into bones through a biogenic process as indicators of the time elapsed since death. We hypothesised that the activity of radionuclides incorporated into trabecular bone will more accurately match the activity in the environment and the food chain at the time of death than the activity in cortical bone because of a higher remodelling rate. We found that determining 90Sr can yield reliable PMI estimates as long as a calibration curve exists for 90Sr covering the studied area and the last 50 years. We also found that adding the activity of 210Po, a proxy for naturally occurring 210Pb incorporated through ingestion, to the 90Sr dating increases the reliability of the PMI value. Our results also show that trabecular bone is subject to both 90Sr and 210Po diagenesis. Accordingly, we used a solubility profile method to determine the biogenic radionuclide only, and we are proposing a new method of bone decontamination to be used prior to 90Sr and 210Pb dating.