137Cs Concentrations Research Articles

Numerical modelling of radionuclide uptake by bluefin tuna along its migration routes in the Mediterranean Sea after a nuclear accident

A numerical model which simulates the adsorption of radionuclides by migrating bluefin tuna in the Mediterranean Sea is described, in order to determine the level of contamination of these fish after a hypothetical nuclear accident and thus be able to assess the possible impact on human consumption. A 4–species foodweb model is incorporated into a Lagrangian model describing physical transport (advection, mixing, radioactive decay and interactions of radionuclides with sediments). Tuna is the last trophic level in the foodweb model and the equation providing the temporal evolution of radionuclide concentration in its flesh is solved along the fish trajectories, which were obtained through electronic tagging of fishes. The model was applied to the western Mediterranean, where several worst–case hypothetical accidents were simulated, both from a coastal nuclear power plant and from a vessel. Resulting 137Cs concentrations in migrating tuna were similar, or slightly higher, than reported background concentrations in these fishes and well below established safety levels. Maximum calculated concentrations in tuna flesh is in the order of 1 Bq/kg (wet weight). This is due to the rapid movement of the fishes, which spend only limited time over the most contaminated spots.

The Cross-Verification of Different Methods for Soil Erosion Assessment of Natural and Agricultural Low Slopes in the Southern Cis-Ural Region of Russia

The conventional measuring methods (runoff plots and soil morphological comparison) and models (WaTEM/SEDEM and regional model of Russian State Hydrological Institute (SHI)) were tested with regard to the Southern Cis-Ural region of Russia, along with data from rainfall simulation for assessing soil erosion. Compared with conventional methods, which require long-running field observations, using erosion models and rainfall simulation is less time-consuming and is found to be fairly accurate for assessing long-term average rates of soil erosion and deposition. In this context, 137Cs can also be used as a marker of soil redistribution on the slope. The data of soil loss and sedimentation rates obtained by using conventional measuring methods were in agreement with the data based on the used contemporary modeling approaches. According to the erosion model calculations and data on the fallout of radionuclides in the Southern Cis-Ural (54°50–25′ N and 55°44–50′ E), the average long-term annual soil losses were ~1.3 t·ha−1 yr−1 in moderate (5°) arable slopes and ~0.2 t·ha−1 yr−1 in meadows. In forests, surface erosion is negligible, or its rates are similar to the rate of soil formation of clay–illuvial chernozems. The rates of soil erosion and sediment deposition on the arable land obtained using different methods were found to be very close. All the methods, including the WaTEM/SEDEM, allowed us to measure both soil erosion and intra-slope sedimentation. The regional SHI model fairly accurately assesses soil erosion in the years when erosion events occurred; however, soil erosion as a result of snowmelt did not occur every year, which should be taken into account when modeling. The concentrations of 137Cs in the topsoil layer (0–20 cm) varied from 0.9 to 9.8 Bq·kg−1, and the 137Cs inventories were 1.6–5.1 kBq·m−2, with the highest values found under the forest. The air dose rate in the forest was higher than in open areas and above the average of 0.12 μSv·h−1 on the slope (0.1 μSv·h−1 in the meadow and 0.08 μSv·h−1 on the arable land), with the value increasing from the watershed to the lower part of the slope in all the areas. The γ-background level in the studied ecosystems did not exceed the maximum permissible levels.

The Effect of Radionuclide and Chemical Contamination on Morphological and Anatomical Parameters of Plants

This article presents the results of a study of the influence of radionuclide and chemical pollution on the morphological and anatomical parameters of Calamagróstis epigéjos plants growing in the territory of “Degelen” at the Semipalatinsk Test Site (STS). Quantitative data of morphological and anatomical parameters are given, and the content of radionuclides and toxic elements in samples of plants obtained. Statistical processing of the obtained data was conducted. The results revealed that elevated concentrations of radionuclides 137Cs and 90Sr, and the calculated absorbed dose, do not have effects on plants. Changes in the anatomical parameters of leaves and stems were observed at elevated concentrations of the elements: for leaves—Al, Pb, Sr, U, Ni, Rb, Sm; for stems—Al, Cr, Cd, U, Cu, Be, Ni, Sm, Fe. The mesophyll of the leaves and the epidermis of the stems were the most exposed to toxic elements. The data of the anatomical parameters are recommended to be used as indicative parameters of plants grown in chemically contaminated areas.

Радиоэкологические исследования в районе архипелага Земля Франца-Иосифа в августе и сентябре 2023 года

The results of a study of the current activity of technogenic isotopes in the coastal zone of the Alexandra Land island of the Franz Josef Land archipelago are presented. Samples of sea water, algae, bottom sediments, soil and vegetation were taken during an expedition carried out under the auspices of the Northern Fleet and the Russian Geographical Society in August and September 2023. In the marine environment and littoral macrophytes, the content of technogenic 137Cs is gradually decreasing in comparison with the indicators of the previous period 2000–2010. In the terrestrial ecosystem, the distribution 137Cs is mosaic; the highest specific activity is found in soils (up to 71.4 Bq/kg). In single samples, the presence of the short-lived isotope 134Cs was noted, which is an indicator of relatively recent atmospheric fallout in the Arctic.

Activity concentrations of 60 Co, 137Cs and 241Am in sieved soil and soil inclusions from the «Taiga» peaceful nuclear explosions site

The article presents results of comparative study of 137Cs, 60Co, and 241Am activity concentrations in components of the soil samples collected in 2009 on the territory adjacent to the «Taiga» peaceful nuclear explosions site (the Perm region, Russia). The objective of the study was to identify differences between: 1) non fractionated native soil, 2) the soil passed through a sieve with a mesh size of 1.2 mm, and 3) the screened out coarse components. Measurements of the radionuclides activities in counting samples were performed using a semiconductor gamma spectrometer. Statistically significantly lower activity concentrations of 137Cs (factor of 1.2), 60Co (factor of 2.2) and 241Am (factor of 2.6) were found in the finely dispersed sieved fraction of soil compared to the native soil. On the opposite, in the solid radioactive inclusions selected from the screened out coarse fraction, the activity concentrations of 137Cs, 60Co and 241Am were significantly higher compared to those in the native soil. Especially large differences (up to a factor of 10 and more) between the native soil and radioactive inclusions were observed for the refractory and low-volatile 60Co and 241Am. Presumably, these radionuclides were concentrated predominantly in the glassy substance of the radioactive inclusions. For 137Cs, the unevenness in the contamination of different soil components was less pronounced. The results obtained will be used to standardize methods for assessing radioactive contamination of the territory at the sites of peaceful nuclear explosions

Dynamics of 137Cs concentrations in cow milk in the districts of Bryansk region

The publication continues the series of research addressed to the dynamics of 137Cs concentrations in agricultural products after the Chernobyl accident. The purpose of the present paper was to analyze the data describing the changes of 137Cs concentrations in cow milk. The information on countermeasures in animal breeding is presented, the system of radiological monitoring of milk contamination is described. It is shown that the dynamics of 137Cs concentrations in milk was seriously affected by the implementation of agrotechnical and veterinary measures. Effective half-lives of 137Cs concentrations in milk in the first period after the accident (1987-1992) ranged from 1 to 2.0 years. In the subsequent period (1991-2015), the reduction of milk contamination slowed down and the half-lives ranged from 5 to 25 years depending on the scope of remediation works and 137Cs aging in the soil.

Development of a three-dimensional variational data assimilation system for 137Cs based on WRF-Chem model and applied to the Fukushima nuclear accident

Abstract Nuclear explosions and accidents release large amounts of radionuclides that harm human health and the environment. Accurate forecasting of nuclide pollutants and assessment of the ramifications of nuclear incidents are necessary for the emergency response and disaster assessment of nuclide pollution. In this study, we developed a three-dimensional variational (3Dvar) system to assimilate 137Cs based on the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) model. The distribution of 137Cs after the Fukushima nuclear accident in Japan on 15 March 2011 was analysed. The 137Cs background field at 06:00 UTC was assimilated using a 3Dvar system and surface observational data to optimise the 137Cs analysis field. Compared with the background field, the root mean square error (RMSE) and mean bias in the 137Cs analysis field decreased by 98% and 94%, respectively. The average fraction of predictions within factors of 2 (FAC2), 5 (FAC5), and 10 (FAC10) increased from 0.67, 0.72, and 0.72 to 0.90, 1.00, and 1.00, respectively. This substantial enhancement indicated the effectiveness of the 3DVar system in mitigating the uncertainty associated with the background field. Two 12 h forecast experiments were conducted to gauge the advancement in 137Cs forecasting facilitated by data assimilation (DA). The control experiment was conducted without DA, whereas the assimilation experiment was conducted with DA. Compared with the control experiment, the average FAC2, FAC5, and FAC10 in the assimilation experiment increased by 28%, 30%, and 29%, respectively. The average RMSE decreased by 33%. The mean bias and correlation coefficient increased by 41% and 36%, respectively. These results indicated that the 3Dvar method improves the forecast accuracy of 137Cs concentration.

Спектрометрія 90Sr

A spectroscopic method has been developed based on measuring of beta-spectra, which takes into account the physico-chemical state of the investigated objects and the instability of electronic systems in field conditions. This method allows for the investigation of the 90Sr and 137Cs concentration in various objects with a change in the 137Cs/90Sr ratio from 1 to 100 with an error of better than 20 %. A methodology has been developed that takes into account the change in the density of the inanimate objects and is based on shifting of the peak position of the conversion electrons from the 137Cs decay. The verification of the methodology compared to radiochemical measurements of 90Sr in soil samples showed complete agreement within 10 - 15 %, with a change of the activity in the samples by four orders of magnitude.

Natural radionuclide and <sup>137</sup>Cs activity concentration in soils of the Brazilian State of Sergipe and their correlation with environmental characteristics

Radionuclides occur naturally in the environment, exposing living organisms to ionizing radiation. In addition, human activities have introduced artificial radionuclides such as 137Cs, among others, into the environment. To better understand the occurrence and behaviour of radionuclides in soil, several countries have developed radiological studies and constructed maps. An effort has been made in Brazil to assess the radioactivity in the soils of the country. In this study, the activity concentrations of natural radionuclides 40K, 226Ra and 228Ra, and artificial 137Cs were determined in samples at a depth of 20 cm collected from the soils of the Brazilian State of Sergipe, in a regular grid of 25 km x 25 km. Samples were analysed by gamma-ray spectrometry with the use of hyperpure germanium detectors. The results were correlated with the type of soil, geology, and climate characteristics of the State. The median activity concentrations of 40K, 226Ra, and 228Ra were 210.4 Bq.kg-1, 12.33 Bq.kg-1, and 18.69 Bq.kg-1, respectively. The results are lower than those reported for soils from other Brazilian States in the same region. The activity concentration of 137Cs was lower than the minimum detectable activity. The activity concentration of 40K in young soils of the semi-arid region was higher than that found in most weathered soils of the rainy regions due to the very low pluviometry of the semi-arid area. Higher activity levels of 226Ra were found in Planosol and for 228Ra it was found in the weathered soils (Acrisol) of the coastal zone. Maps of the distribution of the studied radionuclides were designed. The median value of the outdoor absorbed dose rate in air (Dnat) calculated for the soils of the State of Sergipe is lower when compared with other Brazilian States and the UNSCEAR’s worldwide median value.

Distinct food-web transfers of 137Cs to fish in river and lake ecosystems: A case study focusing on masu salmon in the Fukushima evacuation zone

This study was conducted to elucidate the spatial and size variations, and food-web transfer of 137Cs in freshwater fish in the upper reaches of the Ukedo River system, a highly contaminated river system flowing through the Fukushima evacuation zone. Fish collection and environmental surveys were conducted in the summer of 2020 at five forest rivers and at the Ogaki Dam reservoir (an artificial lake) with different air dose rates (mean 0.20–3.32 μSv/h). From the river sites, two salmonid species (masu salmon and white-spotted charr) were sampled, with masu salmon generally exhibiting higher 137Cs concentrations, ranging widely (10.6 Bq/kg-wet to 13.0 kBq/kg-wet) depending on the fish size (size effect) and site. The 137Cs concentrations in masu salmon were explained by the air dose rates, 137Cs concentrations in water, sediments (excluding the lake site), and primary producers, with site-specific variations. In the rivers, masu salmon (fluvial type with parr marks) mainly fed on terrestrial insects with higher 137Cs concentrations compared with those of aquatic insects, indicating that 137Cs was transferred mainly to fish through the allochthonous forest food-web during summer. In the lake, masu salmon (lake-run type with larger size and silvery body coloration) mainly preyed on smaller fish with lower 137Cs concentrations, demonstrating that 137Cs is transferred to fish through the autochthonous lake food-web with biomagnification. Differences in 137Cs concentrations among masu salmon (mean 441 Bq/kg-wet) and other fish species (mean 74.8 Bq/kg-wet to 2.35 kBq/kg-wet) were also found in the lake. The distinct 137Cs transfers to river and lake fish were supported by stable isotope analysis: δ15N and δ13C values enriched stepwisely through the food-webs were, respectively, higher and lower in the lake. Our results obtained using multiple approaches clearly revealed the distinct food-web transfer of 137Cs in river and lake ecosystems. These findings can contribute to prediction of radioactive contamination in freshwater fish in the Fukushima evacuation zone.

Preparation, Evaluation, and Bioinformatics Study of Hyaluronic Acid-Modified Ginsenoside Rb1 Self-Assembled Nanoparticles for Treating Cardiovascular Diseases.

(1) Objective: To optimize the preparation process of hyaluronic acid-modified ginsenoside Rb1 self-assembled nanoparticles (HA@GRb1@CS NPs), characterize and evaluate them in vitro, and investigate the mechanism of action of HA@GRb1@CS NPs in treating cardiovascular diseases (CVDs) associated with inflammation and oxidative stress. (2) Methods: The optimal preparation process was screened through Plackett-Burman and Box-Behnken designs. Physical characterization of HA@GRb1@CS NPs was conducted using transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry. Stability experiments, in vitro drug release studies, and lyophilisate selection were performed to evaluate the in vitro performance of HA@GRb1@CS NPs. The anti-inflammatory and antioxidant capabilities of HA@GRb1@CS NPs were assessed using H9c2 and RAW264.7 cells. Additionally, bioinformatics tools were employed to explore the mechanism of action of HA@GRb1@CS NPs in the treatment of CVDs associated with inflammation and oxidative stress. (3) Results: The optimal preparation process for HA@GRb1@CS NPs was achieved with a CS concentration of 2 mg/mL, a TPP concentration of 2.3 mg/mL, and a CS to TPP mass concentration ratio of 1.5:1, resulting in a particle size of 126.4 nm, a zeta potential of 36.8 mV, and a PDI of 0.243. Characterization studies confirmed successful encapsulation of the drug within the carrier, indicating successful preparation of HA@GRb1@CS NPs. In vitro evaluations demonstrated that HA@GRb1@CS NPs exhibited sustained-release effects, leading to reduced MDA (Malondialdehyde) content and increased SOD (Superoxide Dismutase) content in oxidatively damaged H9c2 cells. Furthermore, it showed enhanced DPPH (2,2-Diphenyl-1-picrylhydrazyl) and ABTS+ [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] free radical scavenging rates and inhibited the release of inflammatory factors NO (Nitric Oxide) and IL-6 (Interleukin-6) from RAW264.7 cells. (4) Conclusions: The HA@GRb1@CS NPs prepared in this study exhibit favorable properties with stable quality and significant anti-inflammatory and antioxidant capabilities. The mechanisms underlying their therapeutic effects on CVDs may involve targeting STAT3, JUN, EGFR, CASP3, and other pathways regulating cell apoptosis, autophagy, anti-lipid, and arterial sclerosis signaling pathways.

Radioecological characteristics of Siberian roe deer (Capreolus pygargus Pal., 1771) inhabiting locations of nuclear weapon tests.

This paper reports the activity concentrations of 137Cs, 90Sr, 239+240Pu, 241Am, and 3Н in the form of tritiated water (НТО) and organically bound tritium (ОBТ) in the tissues and organs of roe deer (Capreolus pygargus Pal., 1771) that inhabit the 'Degelen' test location of the Semipalatinsk Test Site. Tissues and organs were sampled from six deer by killing. The activity concentrations of specific radionuclides in the samples were measured using γ-, α-, and β-spectrometry. The radionuclide activity concentrations in the tissues and organs showed considerable variation, for example, 0.6-170 Bq kg-1 for 137Cs and 0.3-2.8×103 Bq kg-1 for 90Sr. The activity concentrations of radionuclides in animal muscular tissue did not exceed permissible values for the meat of wild animals. The tissues and organs in the roe deer were arranged as follows in descending order of their ability to accumulate 137Cs and 90Sr: for 137Cs, muscular tissue-kidneys-lungs-spleen-heart-liver-bone tissue; for 90Sr, bone tissue-liver-lungs-muscular tissue-spleen-heart-kidneys. The activity concentrations of 241Am and 239+240Pu did not exceed the minimum detectable activity. Therefore, no quantitative values could be determined for 241Am, and the 239+240Pu activity concentration could be derived for only one sample: 0.5±0.1 Bq kg-1 (liver). The distribution pattern of these radionuclides in the tissues and organs of the roe deer could not be determined because of insufficient data. The HTO volumetric activity in the tissues and organs of the examined animals ranged from 2.6×10-2 to 77 kBq l-1; activity concentration of OBT, 3.0×10-2 to 16 kBq kg-1; and OBT-to-HTO ratios, 2.0×10-3 to 5.3×102. This ratio can serve as an indicator of how long the examined animals stay in radioactively contaminated ecosystems. Within the 'Degelen' site, the activity concentrations of 90Sr and tritium, in the form of HTO and OBT, are expected to be high in the bone tissues, soft tissues, and organs, respectively.

Cesium accumulation and plant growth promotion characteristics of Paecilomyces lilacinus A10 isolated from Brassica juncea L. rhizosphere soil

The combined microbial-plant remediation has increasingly been used to remediate heavy metal-contaminated soil. Some microorganisms could enhance phytoremediation efficiency by solubilizing heavy metal and improve plant growth by producing phytohormones in the heavy metal contaminated soils. In the present study, a strong cesium (Cs)-tolerant fungal strain Paecilomyces lilacinus was identified from soil microorganisms contaminated with Cs, and the enrichment conditions for Cs were optimized. Furthermore, the effects of the A10 fermentation solution on the growth of Indian mustard (Brassica juncea L.) seedlings were investigated. The results indicated that the optimal combination of factors consisted of a culture temperature of 28 °C, pH7.0, initial concentration of Cs at 5.91 g·L−1. The maximum enrichment of Cs in the A10 was up to 75.36 mg·g−1 DW. In addition, the enrichment of Cs in Indian mustard was significantly enhanced by the application of the A10 fermentation solution, and the growth of Indian mustard was promoted under Cs stress. The present study has expanded the repertoire of microbial resources available for facilitating the Cs contaminated soil, thereby enhancing its applicability in the phytoremediation strategies.

In Situ Growth of Gold Nanofilms with Branched Structures in the Presence of Organosulfur for High-Performance Flexible Electronics.

Herein, a novel method is presented for the in situ growth of gold nanofilms with branched structures in the presence of organosulfur. The key feature in this approach is the Rayleigh instability of ultrathin gold nanowires (AuNWs) without oleylamine (OAm), which allows the ultrathin AuNWs to decompose into gold nanoparticles (AuNPs) and the AuNPs to in situ grow into branched structures for high-performance stability and electrical conductivity. The sheet resistance of the gold nanofilms initially sharply decreased, whereas it subsequently slightly increased with the concentration of CS(NH2)2 until it exceeded the optimal range. After undergoing a 10 min heat treatment at 150 °C, the sheet resistance of the nanofilms was further reduced to 18 Ω/sq, which could be maintained for more than five months. The internal structure becomes fully grown and denser, forming a branched structure after heat treatment. Only certain organosulfurs can improve the electrical properties of the gold nanofilms, and the mechanism of organosulfur in the in situ growth of gold nanofilms with branched structures has also been presented. Overall, this novel method provides a straightforward and convenient approach to obtaining gold nanomaterials with branched structures, holding great potential promise for applications in flexible electronics, catalysis, and energy fields.

Enhancing performance of low-temperature fabricated inverted planar perovskite solar cells through triple-cation perovskite optimization

Perovskite solar cells have garnered significant attention due to the rapidly advancing power conversion efficiency(PCE). Recently, there has been significant interest in enhancing the performance of perovskite solar cells through Cs+ doping. However, the optimal concentration of Cs+ varies between inverted and positive structures, influenced by factors such as cell design, fabrication processes, and performance optimization requirements. In this study, we designed and prepared a novel inverted structure triple cations FA/MA/Cs perovskite solar cell at a low temperature. We observed that the quality of perovskite films can be obviously improved by doping an appropriate amount of Cs+, but excessive Cs+ will destabilize the perovskite structure, leading to rapid film decomposition in ambient air. Our results indicate that employing higher concentrations of Cs+, specifically 10 % and 15 %, leads to superior performance and enhanced stability. Notably, the perovskite solar cell incorporating 10%-Cs exhibits larger grain sizes, uniform particle distribution, and its highest PCE achieves 16.41 %. Our research provides a straightforward and cost-effective strategy for improving the performance of inverted perovskite solar cells utilizing triple cations.

Fluorescence based visual sensing of cesium ions enabled by space-confined converting enriched cesium ions to CsPbBr3 nanocrystals in crown ether functionalized mesoporous silica

Portable fluorescence-based Cs+ radionuclide sensing has received great concerns yet challenged by interference in complex sample matrices. Herein, a reliable method was established by in situ converting the preconcentrated Cs+ to CsPbBr3 perovskite nanocrystals in mesoporous silica modified with dibenzo 24-crown-8 ethers (DB24C8E-SiO2), which combined the selective extraction of Cs+ with in situ fluorescence derivatization to achieve good anti-interference ability. The high adsorption capacity (49.5 mg g−1) of DB24C8E-SiO2 for Cs+ and elution-free operation enabled enrichment factor up to 4500, which was conducive to reducing the limit of detection (LOD) for Cs+. By this method, the fluorescence intensity linearly increased with the Cs+ concentration from 0.050 μg mL−1 to 100 μg mL−1 with an LOD of 0.017 μg mL−1 (S/N = 3). The concentration of Cs+ in seawater sample was detected to be 0.056 μg mL−1. The recoveries of Cs+ in spiked samples remained above 88.90 % and the relative standard deviations were less than 12.06 %. In addition, the relative errors of this method were within ±13.2 % compared with the result from atomic absorption spectrometry. The study demonstrated the high potential of the method for removal and portable detection of Cs+.

Quality and safety of products using GM soybeans in the diet of bulls

The production of high-quality and safe food products in areas contaminated by radiation due to the Chornobyl Nuclear Power Plant accident remains a pressing issue. The aim of this study was to determine the concentration and transfer factors of 137Cs, Pb, Cd, Cu, and Zn in bull products when including various high-protein feeds, such as narrow-leaved lupin and genetically modified soybean, in their diets. The study employed zootechnical methods (design and conduct of a scientific-economic experiment on animals), radiological and spectrometric methods (determination of the concentration of 137Cs, Pb, Cd, Cu, and Zn in feeds, longissimus dorsi muscle, liver, kidneys, and testes of bulls), and statistical methods. It was established that when using GM soybean in the grain mixture, the concentration of 137Cs in the muscle tissue of animals in Group II (experimental) decreased relative to the control by 2.57 Bq/kg, or by 40.5% with a statistically significant difference between groups (P > 0.99). Furthermore, the transfer factor of the radionuclide into the muscle tissue of animals in Group II compared to Group I also had 2.15% abs. lower. The content of Pb in the muscle tissue of bulls in both experimental groups exceeded the maximum permissible concentration by 2.52-2.78 times, while the concentration of Cd in the longissimus dorsi muscle and Cu in the liver of animals in Group II also exceeded sanitary-hygienic requirements by 10.0% and 2.0%, respectively. The introduction of 40% (by mass) of maize grain and 30% of GM soybean into the grain mixture instead of the same amount of wheat and lupin chop during the fattening of animals in the third zone of radioactive contamination contributed to significantly higher content and transfer of heavy metals into muscle tissue: Pb – by 10.3% and 0.10% abs., Cd – 10.0 and 0.03, Cu – 17.2 and 0.53, and Zn – by 17.2% and 2.40% abs. The results of the research can be used in agricultural enterprises and private households that produce livestock products in areas with a high anthropogenic load

Association of plasma metals with resting-state functional connectivity in ischemic stroke

BackgroundMetal exposure has long been considered a significant risk factor for ischemic stroke. However, existing data on the effects of metal exposure on brain function in ischemic stroke are limited. Therefore, this study aimed to explore the correlation between exposure to various metals and changes in resting-state functional connectivity (rs-FC) in ischemic stroke patients. MethodsThis study included 28 acute ischemic stroke patients with hemiplegia and 28 matched healthy controls (HCs). All participants underwent T1-weighted MRI and 3.0 T resting-state functional magnetic resonance imaging (fMRI). After MRI acquisition, the rs-FC between 137 cortical and subcortical regions was extracted and preprocessed. Plasma levels of 19 metals were measured using inductively coupled plasma mass spectrometry (ICP-MS). The Bayesian kernel machine regression (BKMR) model and the weighted quantile sum regression (WQS) model were used to assess the overall effect of metal mixture exposure. The severity of neurological deficits in each acute ischemic stroke patient was evaluated using the National Institutes of Health Stroke Scale (NIHSS). Additionally, the associations between exposure to various metals and modifications in brain functional connectivity were determined using Pearson or Spearman correlation analysis. ResultsBilateral brain connectivity was significantly decreased compared to controls and was associated with neurological impairment in ischemic stroke. In patients with ischemic stroke, the plasma concentrations of Cr (p < 0.001), Cu (p = 0.004), As (p = 0.010), Cs (p = 0.046), Rb (p = 0.041), and Sb (p = 0.001) were significantly higher than those in the HCs, whereas the plasma Tl concentrations (p = 0.022) were significantly lower. The results of the BKMR and WQS models showed that combined exposure to metal mixtures was linked to a higher risk of ischemic stroke. Cr was positively correlated with the rs-FC between the left Rolandic_Oper and the left Supp_Motor_Area (r = 0.414, p = 0.029), while negatively correlated with the rs-FC between the right Parietal_Inf and the left supramarginal (r = −0.398, p = 0.037). Cu was negatively correlated with the rs-FC between the left paracentral lobule and the left thalamus (r = −0.409, p = 0.031). Tl was positively correlated with the rs-FC between the right Parietal_Inf and the left supramarginal cortex (r = 0.590, p = 0.001). A negative correlation was observed between Cs and rs-FC between the right Cingulate_Mid and left Occipital_Sup (r = −0.429, p = 0.024). Sb was negatively correlated with the rs-FC between the left Parietal_Inf and the right SupraMarginal (r = −0.384, p = 0.044), the right Parietal_Inf and the left SupraMarginal (r = −0.583, p = 0.001), and the left SupraMarginal and the right SupraMarginal (r = −0.377, p = 0.048). ConclusionPlasma levels of Cr, Cu, Tl, Cs, and Sb were associated with altered rs-FC in brain regions related to motor control, sensory integration, executive function, language processing, and emotional regulation in ischemic stroke patients with basal ganglia infarction.

A hybrid adsorption / ultrafiltration membrane process for removal of Cs-137 from radioactive wastewater using natural clay adsorbent

The removal of radioactive cesium element (Cs-137) from wastewater is relatively challenging due to its high diffusion coefficient, short hydration radius, and the similarity between its chemical behavior to other alkali metals having high background concentrations, leading to a competition that reduces the removal efficiency of cesium (Cs-137). This study introduces an innovative treatment process using a submerged membrane adsorption hybrid system (SMAHS) using natural Iraqi clay minerals as adsorbents. The operational conditions were studied using the (SMAHS) continuous flow operation in stirred filtration mode experiments. The maximum operational conditions were achieved for the initial radioactivity concentration of Cs-137 at 7201.8 Bq/L, clay dose 1 g/L, the stirring speed at 700 rpm, pH =6, the transmembrane pressure (TMP) under 2 bar, and temperature at 25 °C. The SMAHS rejection percentage of Cs-137 was 93.6 % and the permeate flux was 105.6 L/m2.h at the best operational conditions. This study demonstrates that utilizing raw bentonite which is both environmentally friendly and locally available as an adsorbent in the SMAHS has proven its effectiveness for removing Cs-137 from wastewater. The hybrid method effectively immobilizes radioactive waste by converting it from liquid to solid state, leading to an extended and safer storage time.

МИГРАЦИИОННАЯ АКТИВНОСТЬ 137CS В АГРОПРОДУКЦИЮ БИОГЕОЦЕНОЗОВ КРАСНОЯРСКОГО КРАЯ

The purpose of the study is to determine the intensity of 137Cs movement along the trophic chain “soil – diet – livestock products” in the agricultural landscapes of the Krasnoyarsk Region with additional radiation load. A literature review of scientific data characterizing the features of the migration activity of 137Cs in the links “soil – feed – livestock products” in agrobiocenoses with radioactive contamination above established standards is given. Based on the results of a radioecological survey of agricultural landscapes in the central regions of the Krasnoyarsk Region and calculation of absorbed doses, the author identified agricultural landscapes with additional technogenic pollution and determined the specific activity of 137Cs in feed and cow's milk in agricultural landscapes with additional technogenic load. The specific activity values of 137Cs in agricultural landscape feeds with doses of 1.33 and 1.55 mGy/year are higher than the background va¬lue for the Krasnoyarsk Region. The content of 137Cs in livestock products produced in farm biogeocenoses with additional technogenic load is higher than the average for the region, but does not exceed the criterion of regulatory documents; accordingly, radiation-safe agricultural products are produced on the territory of the Krasnoyarsk Region. For agricultural landscapes with absorbed doses of 1.33 and 1.55 mGy/year, a KP for the link “feed – livestock products” has been established. When the radioecological situation changes, the established Kp values can be used to predict the migration of 137Cs in the chain “soil – feed – livestock products”. A direct linear moderate Spearman rank correlation was identified between the specific activity of 137Cs in feed and the concentration of 137Cs in cow's milk. Linear regression equations have been determined to determine the specific activity of cow's milk based on data on the specific activity of 137Cs in feed. The revealed direct linear relationship indicates that even a slight increase in the 137Cs activity of the diet leads to an equivalent increase in the specific activity of technogenic cesium in cow's milk.