Activation Analysis Research Articles

Moss Technique Used to Monitor the Atmospheric Deposition of Trace Elements on the Territory of the Ryazan Region, Russia

Instrumental neutron activation analysis in combination with the method of moss biomonitoring for the assessment of atmospheric deposition of heavy metals and other elements was applied for the first time in the Ryazan Region in Russia. Concentrations of 42 macro, micro and trace elements in 63 moss samples (Hylocomium splendens and Pleurozium schreberi, as well as Hypnum cupressiforme, Sciuro-hypnum sp., Plagiothecium sp. and Ptilium sp.), collected on a relatively uniform grid in the study area, were determined. On the basis of analytical results using GIS technologies, maps of the spatial distribution of heavy metals and other toxic elements were constructed for the Ryazan region. The method of multivariate statistical analysis (factor analysis) was used to identify the main sources of pollution—large industrial facilities located in this region. The obtained results were included in the Atlas of Atmospheric Deposition of Heavy Metals, which is published by the UN Commission on Long-Range Transboundary Air Pollution (UNECE ICP Vegetation).

Radionuclides' Dispersion from Coal-Fired Brick Kilns: Geo-Environmental Processes, Potential Risks and Management.

In order to investigate the distributions and possible dispersion mechanism(s) of naturally occurring radioactive materials (NORMs: 226Ra, 232Th, and 40K) from coal-based brick kilns, a systematic set (n = 60) of coal, ash, surface-soil, and subsurface soil samples were analyzed. High-quality analytical data of U, Th and K obtained from HPGe detector and TRIGA Mark-II research reactor-based neutron activation analysis were converted to the corresponding radioactivities. Average (n = 10) radioactivities of 226Ra, 232Th, and 40K in coal samples were 15.6, 16.7, and 145.5Bq.kg-1, respectively, where only 40K surpassed the corresponding global mean value. Average (n = 10) radioactivities of 226Ra, 232Th, and 40K in ash samples were 62.7, 88.5, and 521Bq.kg-1, respectively, where only 226Ra was within the established limit. In soil samples, average (n = 40) activities of 226Ra, 232Th, and 40K were 62.7, 95.1, and 641Bq.kg-1, respectively, which have surpassed the corresponding worldwide mean values. The observed differences in activity levels between soil samples collected near and far from the kilns, as well as between topsoil and subsoil samples, suggest the presence of distinct transport mechanisms for NORMs within the pedosphere. Dispersions of NORMs from the brick kilns to the ambient pedosphere are largely governed by aerodynamic convection and hydrodynamic leaching. These mechanisms are also influenced by geochemical mobility and relative solubility of NORMs, as well as factors such as rainfall patterns and wind-flow direction. Radiological indices invoke long-term carcinogenic-risks, whereas aerodynamic convection of finer particles (coal fly ash) from chimneys can cause significant health hazards to the nearby dwellers. Scientific processes as well as public awareness are essential to mitigate the risks.

Application of LIBS and LA-ICP-MS analysis to Hellenistic tableware

Greek and Hellenistic painted vases have attracted scholars of classical archaeology for centuries, either because of the artistic value of the painted decorations or because of the depicted scenes of ancient everyday life. Due to the application of thin slips on the surface, different methods are used for the chemical characterisation of the slips and the body of the same vase. The slips are commonly analysed by X-ray microanalysis, offering point-by-point analysis of mostly major elements, while different tools, such as X-ray fluorescence (XRF), inductively coupled mass spectrometry (ICP-MS), and instrumental neutron activation analysis (INAA), are used for bulk body analysis. This can cause difficulties in comparing the bulk composition and thus in determining the similarities and differences in the preparation process of the clay paste for the slips and bodies of an object. Given the artistic value of these objects, museum curators tend to be reluctant to provide samples for invasive characterisation. Micro-destructive laser ablation methods offer a robust solution to addressing both the relationships between ceramic body and surface treatment chemistry and destructive sampling. To provide a proof-of concept, we analysed slips and bodies of a small sample of Hellenistic fine wares from the Greek colony of Issa in modern Croatia with Laser-Induced Breakdown Spectroscopy (LIBS) and Laser ablation-ICP-MS. Results show remarkable diversity in the use of clay types and processing techniques.

Sensitivity improvement of a deuterium-deuterium neutron generator based in vivo neutron activation analysis (IVNAA) system.

Our lab has been developing a deuterium-deuterium (DD) neutron generator-based neutron activation analysis (NAA) system to quantify metals and elements in the human body in vivo. The system has been used to quantify metals such as manganese, aluminum, sodium in bones of a living human. The technology provides a useful way to assess metal exposure and to estimate elemental deposition, storage and biokinetics. It has great potential to be applied in the occupational and environmental health fields to study the association of metal exposure and various health outcomes, as well as in the nutrition field to study the intake of essential elements and human health. However, the relatively low sensitivity of the system has greatly limited its applications. Neutron moderation plays an important role in designing an IVNAA facility, as it affects thermal neutron flux in irradiation cave and radiation exposure to the human subject. This study aims to develop a novel thermal neutron enhancement method to improve the sensitivity of the in vivo neutron activation analysis (IVNAA) system for elemental measurement but still maintain radiation dose. Utilizing a compact DD neutron source, we propose a new and practical moderator design that combines high density polyethylene with heavy water to enhance thermal neutrons by reducing thermal neutron absorption. All material dimensions are calculated by PHITS, a general-purpose Monte Carlo simulation program. The improvement of the new design predicted by the Monte Carlo simulation for the quantification of one of the elements, manganese was verified by experimental irradiation of manganese-doped bone equivalent phantoms. For the same radiation dose, a 67.9% thermal neutron flux enhancement is reached. With only 4.2% increase of radiation dose, the simulated thermal neutron flux and activation can be further increased by 84.2%. A 100% thermal neutron enhancement ratio is also achievable with a 20% dose increase. The experimental results clearly show higher manganese activation gamma ray counts for each specific phantom, with a significantly reduced minimum detection limit. Additionally, the photon dose was suppressed. The thermal neutron enhancement method can increase the number of useful neutrons significantly but maintain the radiation dose. This greatly decreased the detection limit of the system for elemental quantification at an acceptable dose, which will broadly expand the application of the technology in research and clinical use. The method can also be applied to other neutron medical applications, including neutron imaging and radiotherapy.

Experimental gamma coincidence spectra recorded in prompt gamma neutron activation analysis

Experimental gamma coincidence spectra recorded in prompt gamma neutron activation analysis

Mineral Composition of Fifteen Species of Asteraceae Family Growing in the Republic of Moldova Using Neutron Activation Analysis

Members of Asteraceae family have properties enabling their application for medical purposes. The major- and microelement content in 15 medicinal species of the Asteraceae family growing in the National Botanical Garden, Republic of Moldova was determined by instrumental neutron activation analysis. A total of 31 chemical elements, Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Mo, Sb, Cs, Ba, La, Ce, Sm, Tb, Hf, Ta, Th and U, were identified in herbal samples. Potassium was found to be the most abundant major element; its content in plants ranged from 20,700 mg/kg in Artemisia lerchiana to 58,000 mg/kg in Matricaria recutita. The content of other major elements existed in the following ranges: Ca from 4700 to 14,200 mg/kg and Mg from 1710 to 3870 mg/kg. The maximum content of Mg, K and Ca in analyzed plants was higher compared to data presented in the literature. Among essential microelements the most abundant were Fe (83–910 mg/kg), Mn (23–150 mg/kg) and Zn (27–76 mg/kg). The daily intake of metal and the health risk index for selected elements (As, Ni, Sb, V, Mn, Cr, Co, U, Sr, Al, Fe, and Zn) were calculated. Health risk indexes were obtained for V and Co in Calendula officinalis, Tanacetum balsamita, Achillea clypeolata, Artemisia balchanorum, Artemisia lerchiana, Helichrysum arenarium, and Matricaria recutita. The principal component analysis showed three associations of elements, which can be defined as physiological, geological and anthropogenic sources of elements.

Explore the expression of mitochondria-related genes to construct prognostic risk model for ovarian cancer and validate it, so as to provide optimized treatment for ovarian cancer.

The use of gene development data from public database has become a new starting point to explore mitochondrial related gene expression and construct a prognostic prediction model of ovarian cancer. Data were obtained from the TCGA and ICGC databases, and the intersection with mitochondrial genes was used to obtain the differentially expressed genes. q-PCR, Cox proportional risk regression, minimal absolute contraction and selection operator regression analysis were performed to construct the prognostic risk model, and ROC curve was used to evaluate the model for centralized verification. The association between risk scores and clinical features, tumor mutation load, immune cell infiltration, macrophage activation analysis, immunotherapy, and chemosensitivity was further evaluated. A prognostic risk score model for ovarian cancer patients was constructed based on 12 differentially expressed genes. The score was highly correlated with ovarian cancer macrophage infiltration and was a good predictor of the response to immunotherapy. M1 and M2 macrophages in the ovarian tissue in the OV group were significantly activated, providing a reference for the study of the polarity change of tumor-related macrophages for the prognosis and treatment of ovarian cancer. In terms of drug sensitivity, the high-risk group was more sensitive to vinblastine, Acetalax, VX-11e, and PD-0325901, while the low-risk group was more sensitive to Sabutoclax, SB-505124, cisplatin, and erlotinib. The prognostic risk model of ovarian cancer associated to mitochondrial genes built on the basis of public database better evaluated the prognosis of ovarian cancer patients and guided individual treatment.

Determination of fluorine in reference materials by chopped-beam cold neutron prompt gamma-ray activation analysis (CB-CNPGAA)

AbstractA method is described for determination of fluorine in reference materials by chopped beam cold neutron prompt gamma-ray activation analysis (CB-CNPGAA). The chopper cycle is set to 11 s on/off to match the t1/2 of 20F. To reduce systematic error, the F mass is measured as the ratio to a comparator element, either Ca or Cl. The F mass fraction is then calculated by multiplying this ratio by the mass fraction of the comparator element. The method is used to measure F in SRMs 1486 Bone Meal, 1400 Bone Ash, 1566a Oyster Tissue, and 2695 Fluorine in Vegetation.

Application of instrumental neutron activation analysis (INAA) to ceramics and clay sources for the late period (c. 950 years BP) in the Southern Argentine Puna: Interweaving sources, objects and practices

AbstractThe study of the raw materials used in the production of ceramic objects involves studying the materiality of the objects themselves while providing insights into the factors that guided the choice of a particular resource over another. Simultaneously, this article focuses on the social contexts in which these objects were produced. We present the results obtained through an instrumental neutron activation analysis (INAA) of ceramics from the Corral Alto site (Antofagasta de la Sierra, Catamarca) of Argentina. The results suggest that most ceramic pieces were locally manufactured, contrasting with earlier periods and coinciding with the emergence of new ways of dwelling in the Southern Argentine Puna.

Predicting scale thickness in three-phase flow using neutron activation analysis and deep learning

Calcium carbonate scales occur on the inner walls of the pipes used in oil and gas production, reducing the internal diameter and obstructing fluid flow. This study proposes a method for predicting of scale thickness using a neutron source and gamma radiation analysis with a deep neural network (DNN). The detection system includes a 241Am-Be neutron source and 72 detectors that count particles and record photons. A measurement setup was designed using the MCNP6 code to optimize the detection of scale thickness, utilizing a flat neutron source and strategically positioned detectors. The gamma-ray spectra generated from this setup were used as input data for the DNN to predict scale thickness within a three-phase water–gas-oil annular system. The results indicated that the DNN accurately predicted scale thickness with a mean relative error of 3.01 %, achieving a relative error below 5 % for 92.68 % of the dataset, demonstrating the potential for reliable real-time monitoring in industrial settings.

Development of a high-yield compact D-D neutron generator

An improved high-yield compact D-D neutron generator has been developed for active neutron non-destructive interrogation at Lanzhou University in China. The generator has been meticulously designed based on the magnetic field distribution of the duoplasmatron ion source, the electric field distribution of the beam extraction acceleration system, beam transport, and target cooling system. The performance characteristics of the generator were measured under different deuterium beam energies and beam intensities. The experimental results indicated that the D-D neutron yield reached 1×109 n/s with the deuterium beam parameter of 210 keV/6.0 mA. The operational stability of the generator was assessed for 150 minutes, and the test results show that the generator has better stability in operation. This generator has potential applications in neutron radiography, active interrogation of special nuclear materials, and neutron activation analysis.

Validation of MCNPX Calculational Model for Kartini Reactor Outer Core Neutron Flux

Abstract Kartini reactor in Yogyakarta is a nuclear reactor with a low thermal power of 100 kW that is mainly used for education, training, and research. For that purpose, measuring neutron flux and controlling the power are important operational parameters. The Fission Chamber (FC) type of detector is the main component in the reactor operation and safety system that measures the neutron flux in the outer reactor core. As the FC detector is placed in a fixed location, a numerical calculation model is needed to know the neutron flux in all outer core regions. In this study, the MCNPX code is used. The first step is to validate the model with experimental measurement. The objective of the present study is to obtain a validated model by comparing calculations using MCNPX with measurements using gold foil activation (Neutron Activation Analysis technique). The computational model tested showed promising results with an average difference compared to the gold foil activation method of about 23%. Further research can be done using more gold foil samples or foils from other materials to see the consistency of measurements or minimize the measurement difference.

Unveiling the immunomodulatory role of soluble chicken fractalkine: insights from functional characterization and pathway activation analyses

This study describes the first successful cloning and functional characterization of chicken CX3CL1, a chemokine involved in immune cell migration and inflammatory responses. Evolutionary analyses revealed its close relation to CX3CL1 from other avian species, particularly duck, turkey, and quail. Structurally, chicken CX3CL1 includes a signal peptide and a chemokine interleukin-8-like domain characterized by unique alpha-helices and disulfide bonds. Additionally, we produced and purified recombinant CX3CL1 protein and assessed its endotoxin levels. Chemotaxis assays revealed that CX3CL1 significantly enhances the migration of HD11 macrophages and CU91 T cells. Furthermore, recombinant CX3CL1 induced the expression of pro-inflammatory cytokines (TNF-α, IFN-β, IFN-γ, IL-6, and CCL20) in a time-dependent manner, while exerting differential effects on anti-inflammatory cytokines (IL-4, IL-10). Conversely, transfection with siCX3CL1 or siCX3CR1 led to the downregulation of these responses. We also observed activation of the MAPK, NF-κB, and JAK/STAT pathways, evidenced by increased phosphorylation of key signaling molecules. These findings underscore the crucial role of chicken CX3CL1 in regulating immune responses, cell migration, and the activation of key signaling pathways. This study provides valuable insights into the immunomodulatory functions of soluble CX3CL1, highlighting its potential as a therapeutic target for inflammatory conditions and enhancing our understanding of immune cell dynamics.

Action expectancy modulates activity in the mirror neuron system and mentalizing system

Action understanding involves two distinct processing levels that engage separate neural mechanisms: perception of concrete kinematic information and recognition of abstract action intentions. The mirror neuron system and the mentalizing system have both been linked to concrete action and abstract information processing, but their specific roles remain debatable. Here, we conducted a functional magnetic resonance imaging study with 26 participants who passively observed expected and unexpected actions. We performed whole-brain activation, region of interest, and effective connectivity analyses to investigate the neural correlates of these actions. Whole-brain activation analyses revealed that expected actions were associated with increased activation in the left medial superior frontal gyrus, while unexpected actions were linked to heightened activity in the left supramarginal gyrus, left superior parietal lobule, right inferior temporal gyrus, and left middle frontal gyrus. Region of interest analyses demonstrated that the left ventral premotor cortex exhibited greater activation during the observation of expected actions compared to unexpected actions, while the left inferior frontal gyrus, left superior parietal lobule, and left precuneus showed stronger activation during the observation of unexpected actions. Effective connectivity was observed between the left ventral premotor cortex and the left angular gyrus, left intraparietal sulcus, left dorsal premotor cortex, and left ventromedial prefrontal cortex with the middle frontal gyrus when observing unexpected, but not expected, actions. These findings suggest that expected actions are primarily processed by the mirror neuron system, whereas unexpected actions engage both the mirror neuron system and the mentalizing system, with these systems playing complementary roles in the understanding of unexpected actions.

Determination of the silicon content of geological materials by reactor fast neutron activation analysis

Determination of the silicon content of geological materials by reactor fast neutron activation analysis

Determination of sodium, chlorine, and bromine concentrations in breast milk using neutron activation: Correlation, regression, and machine learning predictions

Breast milk plays a vital role in infant health, providing essential nutrients that directly impact nutrition and development. Understanding its elemental composition, as well as the relationships among these elements, is crucial for assessing its nutritional adequacy. This study focused on determining the concentrations of sodium (Na), chlorine (Cl), and bromine (Br) in the breast milk of lactating mothers in Tehran, Iran, during early lactation. The primary objectives were to analyze the concentrations of these elements, investigate their interrelationships, and employ machine-learning techniques to predict their concentrations in breast milk. Neutron activation analysis (NAA) was used to precisely measure the levels of Na, Cl, and Br, while statistical methods, including correlation and regression analyses, were applied to further explore these relationships. Machine-learning models, specifically Random Forest and Linear Regression, were utilized to predict the concentrations of these elements based on their interdependencies. The study revealed mean concentrations of 5.12 mg/g for Na, 8.14 mg/g for Cl, and 11.84 mg/kg for Br in the breast milk samples. A strong positive correlation was observed between Na and Cl (r = 0.976, p < 0.001), while moderate positive correlations were found between Na and Br (r = 0.558, p < 0.001) and Cl and Br (r = 0.606, p < 0.001). Multiple regression models showed that 94.7 % of the variance in Na concentration could be explained by Cl and Br levels (R-squared = 0.947), with a strong positive association between Cl and Na, and a slight inverse relationship between Br and Na. A similar model for Cl concentrations showed strong predictive power, with Na being a significant predictor. However, the model for Br concentrations explained a smaller proportion of variance (R-squared = 0.318), suggesting that additional factors influencing Br levels were not captured in this study. Furthermore, multicollinearity was observed between Na and Cl (VIF = 20.675), indicating potential interactions between these elements. This study highlights the significant correlations between Na, Cl, and Br in breast milk, with particularly strong predictive models for Na and Cl concentrations. The findings also suggest the need for further investigation into the factors affecting Br concentrations. Overall, this research provides valuable insights into the elemental composition of breast milk and its implications for infant nutrition and health.

Concentration and activation biresponsive strategy in one analysis system with simultaneous use of G4 structure-specific signal probe and enzyme-catalyzed reaction

BackgroundEnzymes with critical effects on life systems are regulated by expression and activation to modulate life processes. However, further insights into enzyme functions and mechanisms in various physiological processes are limited to concentration or activation analysis only. Currently, enzyme analysis has received notable attention, particularly simultaneous analysis of their concentration and activation in one system. Herein, N-methyl mesoporphyrin IX (NMM), a specific dye with notable structural selectivity for parallel G-quadruplex nucleic acid enzyme (G4h DNAzyme), is employed for the analysis of its concentration. In addition, the peroxidase activity of G4h DNAzyme is characterized based on G4h DNAzyme–catalyzed decomposition of H2O2 to continuously consume luminol. Accordingly, an increased fluorescence (FL) response of NMM and a decreased FL response of luminol could be simultaneously employed to analyze the concentration and activation of G4h DNAzyme. ResultHerein, a novel concentration and activation biresponsive strategy is proposed using a G4h DNAzyme–based model that simultaneously employs a G4h structure–specific signal probe for enzyme concentration analysis and G4h DNAzyme–catalyzed reactions for enzyme activation analysis. Under optimal conditions, the biresponsive strategy can be effectively used for the simultaneous analysis of G4h DNAzyme concentration and activation, with detection limits of 718.7 pM and 233.4 nM respectively, delivering acceptable performances both in cell and in vitro. SignificanceThis strategy can not only be applied to concentration and activation analyses of G4h DNAzyme but can also be easily extended to other enzymes by simultaneously combining concentration analysis via target-induced direct reaction and activation analysis via target-induced catalytic reaction, offering deeper insights into various enzymes and enabling their effective implementation in bioanalysis and biochemistry.

Trace Element Concentrations of Arsenic and Selenium in Toenails and Risk of Prostate Cancer among Pesticide Applicators.

Prostate cancer is a common cancer among males in the US, but little is known about its risk factors, including trace elements. The primary aim of this study was to examine prostate cancer and its association with arsenic and selenium in toenails. We conducted a small, nested case-control study of men residing in Iowa within the Agricultural Health Study cohort, where we also collected toenail samples to test for arsenic and other trace elements. Toenail samples were sent for neutron activation analysis aimed at long-lived trace elements, including arsenic. Logistic regression was used to estimate odds ratios (ORs) for trace element exposures and prostate cancer. A total of 66 prostate cancer cases and 173 healthy controls returned questionnaires, over 99% of which included toenail samples. An increased risk was seen for the highest levels of arsenic (OR = 3.4 confidence interval (CI) of 1.3-8.6 and OR = 2.2, 95% CI of 0.9-5.6) and the highest level of selenium (2.0, 95% CI of 1.0-4.0). These data also show detectable levels of over 50% for 14 of 22 elements detected in the toenails. The association seen here with arsenic and prostate cancer further supports ecological studies finding an association with community levels of arsenic and prostate cancer incidence and mortality.

NAA-LIMS: a laboratory information management system for neutron activation analysis at the Peruvian institute of nuclear energy

NAA-LIMS: a laboratory information management system for neutron activation analysis at the Peruvian institute of nuclear energy

Neutron activation analysis of Inka pottery from fifteen archaeological sites in the Lurín valley, central coast of Peru: insights into production and exchange

Neutron activation analysis of Inka pottery from fifteen archaeological sites in the Lurín valley, central coast of Peru: insights into production and exchange