A multi-collector ICP-MS method for quantification of plutonium, uranium, and americium in hair and nails of occupationally or medically exposed individuals.

The 239Pu, 238U, and 241Am concentrations and 239Pu/240Pu, 235U/238U, and 236U/238U atom ratios were measured in the hair and nail samples using a new method utilized TEVA, UTEVA, and DGA extraction chromatography and multi-collector ICP-MS. Samples were collected from individuals who donated their bodies to the United States Transuranium and Uranium Registries. The concentration of 239Pu ranged from 0.22 to 15.8 ng/kg. The 240Pu/239Pu isotopic ratios ranged from 0.026 to 0.127 which is consistent with weapons-grade plutonium. Concentration of uranium fell between 1.84 µg/kg and 29.5 µg/kg and 235U/238U ratios ranged from 4.8 × 10-3 to 7.6 × 10-3. Elevated 236U/238U atom ratios were measured in two cases and ranged from 5.0 × 10-6 - 2.4 × 10-5 indicating exposure to spent or reprocessed uranium material. The concentration of 241Am was measured in four hair samples and ranged from 0.02 to 0.21 ng/kg.

Electron paramagnetic resonance dose measurements in teeth of tissue donors to the United States Transuranium and Uranium Registries.

The United States Transuranium and Uranium Registries (USTUR) is a research program that studies actinide biokinetics in occupationally exposed individuals with known intakes of these elements. Electron paramagnetic resonance (EPR) in tooth enamel was applied to reconstruct external doses of nine USTUR registrants. Only in two cases there is a reasonable agreement between the EPR-measured dose and the worksite external dose record. For two registrants, high EPR doses can be explained by possible cancer radiotherapy. For the remaining five cases, EPR doses significantly exceed official occupational doses with no plausible explanation for the observed discrepancy. More EPR dose measurements need to be done to explain this anomaly.

[Challenges of expert assessment of injury to health in the case of iatrogenic mastectomy due to erroneous histological verification of an oncological condition]. / Problemy ekspertnoi otsenki vreda zdorov'yu v sluchae yatrogennogo udaleniya molochnykh zhelez vsledstvie oshibochnoi gistologicheskoi verifikatsii onkologicheskoi patologii.

A case of commission forensic medical examination in the St. Petersburg Bureau of Forensic Science of a civil case due to an unfavorable treatment outcome is presented. Patient T., 45 years old; due to erroneous histological verification of oncological pathology, she had both breasts removed and received antitumor treatment. It has been shown that defects in histological diagnosis can lead to errors by clinicians and become the subject of lawsuits by patients accusing healthcare professionals of adverse treatment outcomes. It is emphasized that the current legislation lacks medical criteria and an algorithm for assessing the severity of injury to health in women with one or both breasts removed.

Eurados review of retrospective dosimetry techniques for internal exposures to ionising radiation and their applications.

This work presents an overview of the applications of retrospective dosimetry techniques in case of incorporation of radionuclides. The fact that internal exposures are characterized by a spatially inhomogeneous irradiation of the body, which is potentially prolonged over large periods and variable over time, is particularly problematic for biological and electron paramagnetic resonance (EPR) dosimetry methods when compared with external exposures. The paper gives initially specific information about internal dosimetry methods, the most common cytogenetic techniques used in biological dosimetry and EPR dosimetry applied to tooth enamel. Based on real-case scenarios, dose estimates obtained from bioassay data as well as with biological and/or EPR dosimetry are compared and critically discussed. In most of the scenarios presented, concomitant external exposures were responsible for the greater portion of the received dose. As no assay is available which can discriminate between radiation of different types and different LETs on the basis of the type of damage induced, it is not possible to infer from these studies specific conclusions valid for incorporated radionuclides alone. The biological dosimetry assays and EPR techniques proved to be most applicable in cases when the radionuclides are almost homogeneously distributed in the body. No compelling evidence was obtained in other cases of extremely inhomogeneous distribution. Retrospective dosimetry needs to be optimized and further developed in order to be able to deal with real exposure cases, where a mixture of both external and internal exposures will be encountered most of the times.

[Physical therapy in the rehabilitation of patients after endoprosthetic replacement of major joints in the lower extremities: a scientometric analysis of evidence-based studies]. / Fizicheskaia terapiia v reabilitatsii patsientov posle éndoprotezirovaniia krupnykh sustavov nizhnikh konechnostei: naukometricheskii analiz dokazatel'nykh issledovanii.

BACKGROUND: In recent decades, the volume of high-tech medical care in the field of orthopedics and traumatology, including endoprosthetic replacement of major joints (MJs) (the hip joint and/or the knee joint) in the lower extremities (LE) (LEMJ), has substantially increased. In this connection, there are an increasing number of patients in need of medical rehabilitation, to solve the problems of which needs the effective physical and rehabilitation medicine (PRM) techniques proven during researches to be introduced into practice. OBJECTIVE: To analyze evidence-based studies containing sound data on the use of PRM technologies in the rehabilitation of patients after endoprosthetic replacement of LEMJs, to identify the most effective PRM technologies and to formulate recommendations for their use for practitioners, which are based on the evidence obtained during the analysis. MATERIAL AND METHODS: The paper is based on the scientometric analysis of 241 studies conducted in 2000 to 2018, which were devoted to the use of physical exercises and PRM technologies in the rehabilitation of patients after endoprosthetic replacement of LEMJs. RESULTS: Over the past decade, there has been a tangible rise in the number of studies on endoprosthetic replacement of LEMJs. Some of the most studied PRM technologies having the proven effect are physical exercises in combination with neuromuscular electrical stimulation, kinesiotherapy, cryotherapy, and pressure therapy that is effective in preventing thromboembolism after surgery. CONCLUSION: The use of PRM technologies in the rehabilitation of patients after endoprosthetic replacement of LEMJs should be based on the results of high-quality randomized controlled clinical trials, which serve as the basis for the development of clinical recommendations. The process of analyzing the data of studies should be regular.

The Mayak Worker Dosimetry System (MWDS 2013): Soluble Plutonium Retention in the Lungs of An Occupationally Exposed USTUR Case.

For the first time, plutonium retention in human upper airways was investigated based on the dosimetric structure of the human respiratory tract proposed by the International Commission on Radiological Protection (ICRP). This paper describes analytical work methodology, case selection criteria, and summarizes findings on soluble (ICRP 68 Type M material) plutonium distribution in the lungs of a former nuclear worker occupationally exposed to plutonium nitrate [239Pu(NO3)4]. Thirty-eight years post-intake, plutonium was found to be uniformly distributed between bronchial (BB), bronchiolar (bb) and alveolar-interstitial (AI) dosimetric compartments as well as between the left and right lungs. 239+240Pu and 238Pu total body activity was estimated to be 2333 ± 23 and 42.1 ± 0.7 Bq, respectively. The results of this work provide key information on the extent of plutonium binding in the upper airways of the human respiratory tract.

The MAYAK WORKER DOSIMETRY SYSTEM (MWDS-2013): ESTIMATION OF PLUTONIUM SKELETAL BURDEN FROM LIMITED AUTOPSY BONE SAMPLES FROM MAYAK PA WORKERS.

The method to estimate total skeleton plutonium burden of former Mayak Production Association (MPA) workers from limited bone samples obtained at autopsy is described. From two to nine bone samples were obtained at autopsies conducted from the mid-1950s to 2013. Plutonium was measured using alpha-radiometry up to 2000 and later by alpha-spectrometry. The method was validated using data from whole-body donations from the United States Transuranium and Uranium Registries (USTUR). The developed algorithm overestimated the USTUR values from 20 to 40%, that is quite acceptable for conservative estimation. Late-in-life liver diseases known to redistribute plutonium between liver and skeleton were not associated with significant differences in plutonium deposition among sampled bones, except for the pelvis. Sources of uncertainties are discussed and future studies will address the reduction of these uncertainties. This algorithm can be used to obtain data in support of the development of biokinetic, dosimetric and risk models for humans exposed to plutonium.

THE MAYAK WORKER DOSIMETRY SYSTEM (MWDS 2013): A RE-ANALYSIS OF USTUR CASE 0269 TO DETERMINE WHETHER PLUTONIUM BINDS TO THE LUNGS.

Radionuclides in ionic form can become chemically bound in the airways of the lungs following dissolution of inhaled particulates in lung fluid. The presence of long-term binding can greatly increase lung doses from inhaled plutonium, particularly if it occurs in the bronchial and bronchiolar regions. However, the only published evidence that plutonium binding occurs in humans comes from an analysis of the autopsy and bioassay data of United States Transuranium and Uranium Registries Case 0269, a plutonium worker who experienced a very high (58 kBq) acute inhalation of plutonium nitrate. This analysis suggested a bound fraction of around 8 %, inferred from an unexpectedly low ratio of estimated total thoracic lymph node activity:total lung activity, at the time of death. However, there are some limitations with this study, the most significant being that measurements of the regional distribution of plutonium activity in the lungs, which provide more direct evidence of binding, were not available when the analysis was performed. The present work describes the analysis of new data, which includes measurements of plutonium activity in the alveolar-interstitial (AI) region, bronchial (BB) and bronchiolar (bb) regions, and extra-thoracic (ET) regions, at the time of death. A Bayesian approach is used that accounts for uncertainties in model parameter values, including particle transport clearance, which were not considered in the original analysis. The results indicate that a long-term bound fraction between 0.4 and 0.7 % is required to explain this data, largely because plutonium activity is present in the extra-thoracic (ET2), bronchial and bronchiolar airways at the time of death.

[On the stability of the irritant dibenz-[b,f]-[1,4]-oxazepine (substance CR)].

The objective of the present study was to determine the duration and conditions of persistence of the irritant dibenz-[b,f]-[1,4]-oxazepine (substance CR) on the environmental objects. The quantitative analysis of the substance on cotton fabric specimens was carried out using the approved method of high performance liquid chromatography (HPLC) with UV detection at different time periods and envirobmental conditions. It was shown that the main factor determining the lifetime of dibenz-[b,f]-[1,4]-oxazepine on the cotton fabric is the ambient conditions. By way of example, the "open" and "closed", storage of such specimens during 300 days resulted in the decrease of the amount of substance CR to 22.5 and 79% of the initial level respectively. By the end experiment (day 600) these values lowered to 3 and 52.5% respectively. Taken together, the results of the study indicate that dibenz-[b,f]-[1,4]-oxazepine can be described as a substance resistant to environmental impacts. It is comparable in terms of stability with such known irritants as capsicum oleoresin and pelargonic acid morpholide.

[The biological activity of the irritant dibenz-[b,f] - [1,4]-oxazepine (substance CR) persisting during a long period at the environmental objects].

The objective of the present study was to determine the biological activity of the irritant dibenz-[B,F]-[1,4]-oxazepine (substance CR) contained in the environmental samples in case of their "closed" storage during different periods of time. The experiments were carried out using male and female rabbits of the Chinchilla strain with the initial body mass of 3000-4000 g. The animals were administered an aqueous alcoholic extract from the tissue samples of the rabbit eye coat as described in the "Methodological guidelines on the medico-biological assessment of the safety of personal protection devices". The results of experiments indicate that extracts from tissue samples elicit irritation in the eyes of the laboratory animals even after their storage as long as 600 days. This observation suggests that substance CR retains the ability to cause irritation during a prolonged period.

EURADOS intercomparison on measurements and Monte Carlo modelling for the assessment of americium in a USTUR leg phantom.

A collaboration of the EURADOS working group on 'Internal Dosimetry' and the United States Transuranium and Uranium Registries (USTUR) has taken place to carry out an intercomparison on measurements and Monte Carlo modelling determining americium deposited in the bone of a USTUR leg phantom. Preliminary results and conclusions of this intercomparison exercise are presented here.

Estimating 241Am activity in the body: comparison of direct measurements and radiochemical analyses.

The assessment of dose and ultimately the health risk from intakes of radioactive materials begins with estimating the amount actually taken into the body. An accurate estimate provides the basis to best assess the distribution in the body, the resulting dose and ultimately the health risk. This study continues the time-honoured practice of evaluating the accuracy of results obtained using in vivo measurement methods and techniques. Results from the radiochemical analyses of the (241)Am activity content of tissues and organs from four donors to the United States Transuranium and Uranium Registries (USTUR) were compared with the results from direct measurements of radioactive material in the body performed in vivo and post-mortem. Two were whole-body donations and two were partial-body donations. The (241)Am lung activity estimates ranged from 1 to 30 Bq in the four cases. The (241)Am activity in the lungs determined from the direct measurements were within 40% of the radiochemistry results in three cases and within a factor of 2 for the other case. However, in one case the post-mortem direct measurement estimate was a factor of 10 higher than the radiochemistry result for lung activity, most probably due to underestimating the skeletal contribution to the measured count rate over the lungs. The direct measurement estimates of liver activity ranged from 2 to 60 Bq and were consistently lower than the radiochemistry results. The skeleton was the organ with the highest deposition of (241)Am activity in all four cases. The skeletal activity estimates ranged from 30 to 300 Bq. The skeletal activity obtained from measurements over the forehead were within 20% of the radiochemistry results in three cases and differed by 78% in the other case. The results from this study suggest that the measurement methods, data analysis methods and calibration techniques used at the In Vivo Radiobioassay and Research Facility can be used to quantify the activity in the lungs, skeleton and liver when (241)Am activity is present in all three organs. The adjustment method used to account for the contribution from activity in other organs improved the agreement between the direct measurement results and the radiochemistry results for activity in the lungs and skeleton. The method appeared to overestimate the contribution from the other organs to the liver activity measurements, although the low activity levels complicated the analysis. The unadjusted liver activity estimates from the direct measurements were generally in better agreement with the radiochemistry results than the adjusted liver activity. The data from this study indicates that the results from the in vivo measurement techniques provide reasonable estimates of radioactive material in the lungs and skeleton under the most challenging conditions where there is (241)Am activity in multiple organs. The data analysis from additional USTUR cases with both direct measurement results and radiochemistry results is in progress to further evaluate how best to account for the contributions from (241)Am activity in multiple organs and to better understand the uncertainty associated with the adjusted activity.

High energy gain of trapped electrons in a tapered, diffraction-dominated inverse-free-electron laser.

Energy gain of trapped electrons in excess of 20 MeV has been demonstrated in an inverse-free-electron-laser (IFEL) accelerator experiment. A 14.5 MeV electron beam is copropagated with a 400 GW CO2 laser beam in a 50 cm long undulator strongly tapered in period and field amplitude. The Rayleigh range of the laser, approximately 1.8 cm, is much shorter than the undulator length yielding a diffraction-dominated interaction. Experimental results on the dependence of the acceleration on injection energy, laser focus position, and laser power are discussed. Simulations, in good agreement with the experimental data, show that most of the energy gain occurs in the first half of the undulator at a gradient of 70 MeV/m and that the structure in the measured energy spectrum arises because of higher harmonic IFEL interaction in the second half of the undulator.

High-power electrostatic free-electron maser as a future source for fusion plasma heating: experiments in the short-pulse regime.

A high-power, frequency-tunable electrostatic free-electron maser, being developed at the FOM Institute for Plasma Physics "Rijnhuizen," shows lasing at various frequencies. An output power of 730 kW at 206 GHz is generated by a 7.2-A, 1.77-MeV electron beam, and 380 kW at 165 GHz is generated by a 7.4-A, 1.65-MeV electron beam. In the present experimental setup, without recovery of the spent electron beam power, the pulse length is limited to 12 micros. Nevertheless, the main issues, such as the possibility of high-power, single-mode operation and frequency tuning, have been confirmed. The experimental results and the dynamics of the laser process are well in accordance with simulations.