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Rapid measurement techniques are required for a large-scale emergency monitoring of people. In vivo measurement of the bremsstrahlung radiation produced by incorporated pure-beta emitters can offer a rapid technique for the determination of such radionuclides in the human body. This work presents a method for the calibration of spectrometers, based on the use of UPh-02T (so-called IGOR) phantom and specific 90Sr/90Y sources, which can account for recent as well as previous contaminations. The process of the whole- and partial-body counter calibration in combination with application of a Monte Carlo code offers readily extension also to other pure-beta emitters and various exposure scenarios. [ABSTRACT FROM AUTHOR]

A simple hemispherical phantom has been designed and prepared for the EURADOS intercomparison exercise on 241Am activity determination in the skull (2011–13). The phantom consists of three parts that substitute bone and soft tissues. 241Am is deposited on the surfaces of the bone-substituting part. The design and assumed composition of phantom parts are discussed. A preparation of the voxel representation of the phantom is described. The spectrum of a real measurement of the physical phantom agrees well with the simulation. The physical phantom, and its voxel representation, is provided to the participants of the intercomparison exercise. [ABSTRACT FROM AUTHOR]

An internal contamination with 241Am was detected in a worker during a routine monitoring of workers from a company producing Am sources for smoke detectors and Am–Be neutron sources. During the 4-year period after the exposure, the number of urine and faecal samples from the worker were analysed; in vivo measurements were also performed. Specific values for absorption parameters of the human respiratory tract model and particle transport values were applied to improve the model fit to the measurement data. A good agreement of the bioassay data with the so-modified model predictions was obtained. [ABSTRACT FROM PUBLISHER]

Urinary excretion of uranium of 40 uranium miners was determined by the high-resolution inductively coupled mass spectrometry method. The concentration of uranium in the urine of the miners was converted to daily excretion of 238U either under the assumption that the daily urinary excretion is 1.6 l or daily urinary excretion of creatinine is 1.7 g and compared with the excretion of 238U calculated with a biokinetic model. Input data to the excretion model were derived from personal three- component ALGADE dosemeters, using the component for the estimation of inhalation of long-lived alpha radionuclides. Experimentally found contents of uranium in the urine of uranium miners are generally lower than the modelled ones, which means that the dosimetric approach is conservative. The uncertainty of inhalation intakes, derived from the measurements of filters from personal dosemeters, and the uncertainty of the concentration of uranium in the urine are discussed. [ABSTRACT FROM AUTHOR]

Uranium in the urine of 10 uranium miners (hewers), 27 members of general population and 11 family members of miners was determined by the High-Resolution ICP-MS method. Concentration of uranium in urine of the miners was converted to daily excretion of 238U under the assumption that the daily excretion of urine is 2 l and compared with the modelled excretion of 238U. Daily excretion of 238U was modelled using input data from personal dosemeters from a component for measurement of intake of long-lived alpha radionuclides. A reasonable agreement between evaluated and measured values was found. The uncertainty of inhalation intakes, derived from measurements of filters from personal dosemeters, and uncertainty of concentration of uranium in urine are discussed. [ABSTRACT FROM PUBLISHER]

Internal contamination of workers with 241Am has occurred a few times since the beginning of the 1970s, mainly in the workplace where radionuclide sources were produced, and later on, also during liquidation of radioactive waste. Contamination in workers was measured in vivo and bioassay was performed. Solubility of aerosol in lungs was studied by in vitro dissolution test with a simulant solution of the extracellular airway lining fluids. Model calculation for the estimation of intakes was done with the experimentally obtained parameters of aerosol, with modified times of intake, with scattering factors, including Types A and B errors, and with corrections on skull size for in vivo measurements. For most cases, an acceptable fit to the experimental data was obtained; for two cases with intakes taking place long time ago (~30 y), some changes in the model are necessary. [ABSTRACT FROM AUTHOR]

Abstract: The studies undertaken by the 131I Working Group, part of the International Atomic Energy Agency''s EMRAS (Environmental Modelling for Radiation Safety) programme, were focused primarily on evaluating the predictive capability of environmental models. Particular emphasis was placed on applying models to evaluate the effectiveness of countermeasures. [Copyright &y& Elsevier]

Agricultural lands with farm animals (e.g. cattle) can be significantly affected by radioactive contamination following nuclear or radiation accidents. In order to optimise the techniques for measuring 137Cs in contaminated cattle, selected radiation detectors have been tested and calibrated using volumetric radiation sources. In addition, a mathematical phantom of a cow was created within Monte Carlo simulations. The main aim of the research was to propose a method for making rapid measurements of 137Cs in cattle in vivo/in situ and to select the most suitable measurement set-up. Measurements of contaminated cattle in vivo were carried out in Belarus with one selected detector, and were then compared with measurements of meat in a laboratory and with measurements of a control group of cows. The proposed measurement method was also tested on measurements of 137Cs in wild boars in Czechia with higher levels of the 137Cs activity., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Nanomedicines are considered next generation therapeutics with advanced therapeutic properties and reduced side effects. Herein, we introduce tailored linear and star-like water-soluble nanosystems as stimuli-sensitive nanomedicines for the treatment of solid tumors or hematological malignancies. The polymer carrier and drug pharmacokinetics were independently evaluated to elucidate the relationship between the nanosystem structure and its distribution in the body. Positron emission tomography and optical imaging demonstrated enhanced tumor accumulation of the polymer carriers in 4T1-bearing mice with increased tumor-to-blood and tumor-to-muscle ratios. Additionally, there was a significant accumulation of doxorubicin bound to various polymer carriers in EL4 tumors, as well as excellent in vivo therapeutic activity in EL4 lymphoma and moderate efficacy in 4T1 breast carcinoma. The linear nanomedicine showed at least comparable pharmacologic properties to the star-like nanomedicines regarding doxorubicin transport. Therefore, if multiple parameters are considered such as its optimized structure and simple and reproducible synthesis, this polymer carrier system is the most promising for further preclinical and clinical investigations., Competing Interests: Declaration of Competing Interest Weibo Cai is a scientific advisor, stockholder, and grantee of Focus-X Therapeutics, Inc. All other authors declare no conflict of interest., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Design, controlled synthesis, physico-chemical and biological characteristics of novel well-defined biodegradable star-shaped copolymers intended for advanced drug delivery is described. These new biocompatible star copolymers were synthesised by grafting monodispersed semitelechelic linear (sL) N-(2-hydroxypropyl)methacrylamide copolymers onto a 2,2-bis(hydroxymethyl)propionic acid (bisMPA)-based polyester dendritic core of various structures. The hydrodynamic diameter of the star copolymer biomaterials can be tuned from 13 to 31 nm and could be adjusted to a given purpose by proper selection of the bisMPA dendritic core type and generation and by considering the sL copolymer molecular weight and polymer-to-core molar ratio. The hydrolytic degradation was proved for both the star copolymers containing either dendron or dendrimer core, showing the spontaneous hydrolysis in duration of few weeks. Finally, it was shown that the therapy with the biodegradable star conjugate with attached doxorubicin strongly suppresses the tumour growth in mice and is fully curative in most of the treated animals at dose corresponding approximately to one fourth of maximum tolerated dose (MTD) value. Both new biodegradable systems show superior efficacy and tumour accumulation over the first generation of star copolymers containing non-degradable PAMAM core., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The time course of 137Cs activity in general population of the Czech Republic has been systematically followed since the Chernobyl accident in 1986. Either whole body counting or the determination of 137Cs content in 24-hour urine samples were used as a method of determination of body activity. Environmental and effective half-lives were calculated from the data. In the time period from 1986 to 1990 the effective half-life was 1.3 years; since 1990 up to present the half-life is 15 years. The older data on whole body activity of 137Cs from 1965 to 1985 were compiled and are presented as well. Apart from the general population, a group of people who have special dietary habits in terms of increased game meat consumption, namely wild boar meat, has been monitored since 2000. In this group, the body content of 137Cs is about two orders of magnitude higher than in the general population., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

The aim of the study is to make a comparison of daily 238U excretion in urine among 115 active uranium miners and its modeled values obtained from inhalation intake of long-lived alpha emitters as measured by personal dosemeters and assessed by biokinetic models for different absorption parameters settings for inhaled uranium. A total of 144 spot samples of urine were collected. The 238U content was measured using high-resolution inductively coupled plasma mass spectrometry method. To obtain estimates of the daily excreted values, the daily values were calculated according to the expected daily excretion of creatinine assessed individually for each miner. When determining the relation between the experimentally found data and the modeled data, a high emphasis was placed on uncertainty of the both compared quantities. All the tested absorption parameters settings produced in average 1.4-4.7-fold higher values than the experimentally found values in the urine., (© The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Ingestion intakes of 137 Cs of the Czech population were calculated in two different ways - either from the measured activity of 137 Cs in components of food in combination with statistical data about consumption rates or from retention of 137 Cs in the human body obtained by whole body counting or calculated from daily urinary excretion of 137 Cs. Data from the time period since 1986 to 2015 are used. The daily ingestion intake was about 25 Bq d -1 in 1986 and is around 0.1 Bq d -1 at present. Both approaches of ingestion intake calculation have their advantages and disadvantages. Ingestion intake calculated from 137 Cs body content was assumed to be the most accurate as it requires fewer assumptions than the calculation from food consumption. However, calculation of 137 Cs intake from food consumption is an important tool for prediction doses after the release of radionuclides into environment. The best agreement exceeding the intakes from urine measurement 5 times at maximum was achieved when intakes calculated from food also included products from the natural environment. Without this, the ingestion intake could be under-predicted seriously up to 6 times, especially in the longer time after the release of 137 Cs into environment. Ingestion intakes up to 11 Bq d -1 in a group of people with significant consumption of game meat containing elevated activity of 137 Cs activity were included as a special case. Various groups of foodstuffs had varying effects on the total committed effective dose from 137 Cs. Dose estimates for the Czech population from 137 Cs ingestion intake achieved 80 μSv in 1986 and not more than 2 μSv currently and were similar to those incurred by the population of neighbouring countries., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The main aim of this study was to determine and evaluate urinary excretion of uranium in the general public of the Czech Republic. This value should serve as a baseline for distinguishing possible increase in uranium content in population living near legacy sites of mining and processing uranium ores and also to help to distinguish the proportion of the uranium content in urine among uranium miners resulting from inhaled dust. The geometric mean of the uranium concentration in urine of 74 inhabitants of the Czech Republic was 0.091 mBq/L (7.4 ng/L) with the 95% confidence interval 0.071-0.12 mBq/L (5.7-9.6 ng/L) respectively. The geometric mean of the daily excretion was 0.15 mBq/d (12.4 ng/d) with the 95% confidence interval 0.12-0.20 mBq/d (9.5-16.1 ng/d) respectively. Despite the legacy of uranium mines and plants processing uranium ore in the Czech Republic, the levels of uranium in urine and therefore, also human body content of uranium, is similar to other countries, esp. Germany, Slovenia and USA. Significant difference in the daily urinary excretion of uranium was found between individuals using public supply and private water wells as a source of drinking water. Age dependence of daily urinary excretion of uranium was not found. Mean values and their range are comparable to other countries, esp. Germany, Slovenia and USA., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Activities of (131)I and (137)Cs excreted in urine from two healthy males during May 1986, when contaminated air masses from Chernobyl arrived on the territory of the Czech Republic, were determined by bioassay. The data were used to estimate the intakes and committed effective doses from these radionuclides. The results for inhalation intakes are of particular interest, in the absence of sufficient contemporary data for airborne activity. They are found to be higher than initial estimates based on air sampling.

A group of workers internally contaminated with Am have been followed for about 12 years. The source of contamination was AmO2 powder used for production of AmBe neutron sources and other applications. The production of some radionuclide sources included chemical treatment of the original material, which transformed the americium into the nitrate, but mostly powder metallurgy was used for production of sources for smoke detectors. In vivo measurement of the workers was performed with two LEGe detectors placed near the head of the measured person. Calibration was performed with four different physical skull phantoms of different origin and a voxel phantom with Monte Carlo simulation, which was developed to fit the head sizes of individual persons. Samples of urine and feces were analyzed by means of radiochemical separation followed by alpha-spectrometry. Separation of 241Am from mineralized excreta was performed by combined anion exchange and extraction chromatographic techniques. As a tracer, 243Am was used. When the measured data (83 data on skeletal activity, activity in 389 bioassay samples) were compared with International Commission on Radiological Protection's and Leggett's biokinetic models of americium, it was found that in most cases, after more than 15 y since the intake, the excretion rate was lower (or skeletal activity higher) than predicted. On the other hand, the ratio of excreted activity in urine and feces agrees well with model predictions.