Nuclear Techniques Research Articles

Toward the Exploitation of Sustainable Green Factory: Biotechnology Use of Nannochloropsis spp.

Securing food, energy, and raw materials for a growing population is one of the most significant challenges of our century. Algae play a central role as an alternative to plants. Wastewater and flue gas can secure nutrients and CO2 for carbon fixation. Unfortunately, algae domestication is necessary to enhance biomass production and reduce cultivation costs. Nannochloropsis spp. have increased in popularity among microalgae due to their ability to accumulate high amounts of lipids, including PUFAs. Recently, the interest in the use of Nannochloropsis spp. as a green bio-factory for producing high-value products increased proportionally to the advances of synthetic biology and genetic tools in these species. In this review, we summarized the state of the art of current nuclear genetic manipulation techniques and a few examples of their application. The industrial use of Nannochloropsis spp. has not been feasible yet, but genetic tools can finally lead to exploiting this full-of-potential microalga.

Application of isotope as a nuclear technique in groundwater pollution assessment due to human activities

Clean and sustainable groundwater is an important asset for human life and ecosystems. However, the threat of groundwater pollution is increasing as a result of human activities such as industrial, agricultural, and municipal. The objective of this review article is to examine how isotope techniques, as one of the nuclear techniques serve as an effective tool in studying, detecting, and understanding the issue of groundwater pollution stemming from anthropogenic activity on the surface. This article covers the description and discussion of the types of isotopes used in the detection of groundwater pollution and factors that influence the variation in the composition of isotopes in groundwater based on the findings of previous studies. In addition, this article also comments on the study of groundwater pollution using isotopes in the context of groundwater pollution assessment in Malaysia. This article serves as a guide or reference to researchers, environmental professionals, and water resources managers who want to understand and implement nuclear techniques in the monitoring and assessment of groundwater pollution. This article also outlines a holistic view on the resolution of groundwater pollution issues through the application of nuclear techniques and isotopes as a significant tool in ensuring sustainable environmental management.

2S-(1RS-benzyloxy-hex-5-enyl)-2,3-dihydro-1,4-benzodioxine

In medicinal chemistry, the precise configuration of molecules is a crucial determinant of their pharmacological properties. Hence, the introduction of a new chiral center during the synthetic pathway involves the assignment of configuration. Herein we assign, by means of molecular modeling 1H and 2D Nuclear Overhauser Effect NMR techniques, the configuration of the two diastereomers 2S-(1R-benzyloxy-hex-5-enyl)-2,3-dihydro-1,4-benzodioxine and 2S-(1S-benzyloxy-hex-5-enyl)-2,3-dihydro-1,4-benzodioxine, which are useful to synthetize analogs of the potent and highly selective dipeptidyl peptidase IV and carbonic anhydrase inhibitor recently published.

MSegResRF-SPECT: A Novel Joint Classification Model of Whole Body Bone Scan Images for Bone Metastasis Diagnosis.

Whole-body bone scanning is a nuclear medicine technique with high sensitivity used for the diagnosis of bone-related diseases [e.g., bone metastases] that can be obtained by positron emission tomography[PET] or single-photon emission computed tomography[SPECT] imaging, depending on the different radiopharmaceuticals used. In contrast to the high sensitivity of the bone scan, it has low specificity, which leads to misinterpretation, causing adverse effects of unwarranted intervention or interruption to timely treatment. To address this problem, this paper proposes a joint model called mSegResRF-SPECT, which accomplishes for the first time the task of classifying whole-body bone scan images on a public SPECT dataset [BS-80K] for the diagnosis of bone metastases. The mSegResRF-SPECT adopts a multi-bone region segmentation algorithm to segment the whole body image into 13 regions, ResNet34 as an extractor to extract the regional features, and a random forest algorithm as a classifier. The experimental results of the proposed model show that the average accuracy, sensitivity, and F1 score of the model on the BS-80K dataset reached SOTA. The proposed method presents a promising solution for better bone scan classification methods.

Pre-treatment of hydrolysable nuclear organic liquids prior to their waste management: Solid impregnation of vegetable oil on surfactant-grafted clay particles

In the context of advancing nuclear waste management techniques, this study delves into the novel use of surfactant-grafted clay particles for pre-treating hydrolysable nuclear organic liquids. Our research explores the potential of modified clay materials in immobilizing vegetable oil, a surrogate for complex nuclear waste. We investigate the adsorption capabilities of various clays, including metakaolin, diatomaceous earth and sepiolite, when grafted with cetyltrimethylammonium bromide (CTAB) as cationic surfactant, or decyl glucoside (DG) as non-ionic surfactant. This study employs characterization techniques to assess the physicochemical transformations in clays post surfactant-grafting. Grafting was initially highlighted by TGA, where the breakdown of surfactants can be observed. This is also evidenced by measurements of the ζ-potential, which demonstrate a reduction in surface charge upon the addition of the cationic surfactant, excepted for sepiolite for which the surface charge did not change. Additionally, Washburn measurements indicate that the grafting process converts hydrophilic particles into hydrophobic ones. The oil absorption tests indicated that the CTAB-grafted sepiolite demonstrated superior characteristics, notably exhibiting no oil rejection. Consequently, this specifically synthesized powder was utilized in a two-step process consisting in pre-impregnation of oil up to 20 %v of vegetable oil prior to its immobilization within a geopolymer matrix. Furthermore, the outcomes of the leaching tests revealed that the vegetable oil remained effectively confined within the immobilization matrix, ensuring its retention. The research contributes to the goal of enhancing hydrolysable nuclear waste management practices, ensuring long-term sustainability and environmental safety.

Towards a unified picture of polarization transfer — pulsed DNP and chemically equivalent PHIP

Nuclear spin hyperpolarization techniques, such as dynamic nuclear polarization (DNP) and parahydrogen-induced polarization (PHIP), have revolutionized nuclear magnetic resonance and magnetic resonance imaging. In these methods, a readily available source of high spin order, either electron spins in DNP or singlet states in hydrogen for PHIP, is brought into close proximity with nuclear spin targets, enabling efficient transfer of spin order under external quantum control. Despite vast disparities in energy scales and interaction mechanisms between electron spins in DNP and nuclear singlet states in PHIP, a pseudo-spin formalism allows us to establish an intriguing equivalence. As a result, the important low-field polarization transfer regime of PHIP can be mapped onto an analogous system equivalent to pulsed-DNP. This establishes a correspondence between key polarization transfer sequences in PHIP and DNP, facilitating the transfer of sequence development concepts. This promises fresh insights and significant cross-pollination between DNP and PHIP polarization sequence developers.

The In Vivo Biological Fate of Protein Corona: A Comparative PET Study of the Fate of Soft and Hard Protein Corona in Healthy Animal Models.

Radiolabeling and nuclear imaging techniques are used to investigate the biodistribution patterns of the soft and hard protein corona around poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) after administration to healthy mice. Soft and hard protein coronas of 131I-labeled BSA or 131I-labeled serum are formed on PLGA NPs functionalized with either polyehtylenimine (PEI) or bovine serum albumin (BSA). The exchangeability of hard and soft corona is assessed in vitro by gamma counting exposing PLGA NPs with corona to non-labeled BSA, serum, or simulated body fluid. PEI PLGA NPs form larger and more stable coronas than BSA PLGA NPs. Soft coronas are more exchangeable than hard ones.The in vivo fate of PEI PLGA NPs coated with preformed 18F-labeled BSA hard and soft coronas is assessed by positron emission tomography (PET)following intravenous administration. While the soft corona shows a biodistribution similar to free 18F BSA with high activity in blood and kidney, the hard corona follows patterns characteristic of nanoparticles, accumulating in the lungs, liver, and spleen. These results show that in vivo fates of soft and hard corona are different, and that soft corona is more easily exchanged with proteins from the body, while hard corona is largely retained on the nanoparticle surface.

3D Reconstruction and Nuclear Analytical Investigations of Tropaeum Traiani Monument, Adamclisi

Abstract The paper aims to conduct a novel investigation of ceramic samples from the Trophaeum Traiani Monument in Romania using various nuclear analytical techniques such as WDXRF, XRD, neutron diffraction, and neutron tomography, which will be complemented by FTIR and Raman spectroscopy data. The experimental data gathered revealed the mineral and chemical composition of the object’s surface, identifying quartz, hematite, calcite, and graphite. The employment of non-destructive techniques with high penetration capabilities is adequate in examining the spatial distribution and phase composition of the samples, providing valuable insights into their composition and structure without altering their integrity.

Simulation of Neutron Leakage Variations at Fuel Substitution in a Small Modular Reactor and Implications for Unattended Safeguards Monitoring

According to a recently proposed nuclear safeguards technique, monitoring the power-normalized, ex-core neutron detection rate over time could be used to detect undeclared changes to the fissile composition of a reactor core. In this study, Monte Carlo simulations have been used to verify some of the underlying assumptions of this technique and the possibilities of using it to detect undeclared fuel substitutions during the first 2-year cycle of a light water small modular reactor. Depletion calculations and neutron transport simulations were used to study the changes in the power-normalized neutron leakage rate J b / P core through the core barrel upon fuel substitutions and whether these changes are fully explained by changes in the core fissile composition. Several substitution scenarios have been studied, where partially depleted fuel assemblies were substituted with fresh fuel assemblies after 1 year of irradiation. The modeled substitution scenarios, which included substituting up to 4 out of 37 fuel assemblies in the core at a time, resulted in changes in J b / P core of up to 3.5% depending on which fuel assemblies were substituted. The results indicate that the ex-core neutron signatures are not only sensitive to core-averaged nuclide densities, fission cross sections, and neutron flux, but also the spatial distributions of these and other parameters throughout the core. Effects such as these could mean that monitoring the core fissile composition with the proposed technique might be more complex than previously suggested.

Development of a polystyrene-based microplastic model for bioaccumulation and biodistribution study using radiotracing and nuclear analysis method

The investigation of micro or nano plastics behavior in the environment is essential to minimize the hazards of such pollutants on humans. While the conventional method requires sophisticated procedures and a lot of animal subjects, the nuclear technique confers a sensitive, accurate, and real-time method using radiolabeled micro or nano plastics as a tracer. In this study, polystyrene sulfonate-based microplastic (PSM) was developed with a size of around 3.6 μm, followed by radiolabeling with iodine-131 (131I) or zinc-65 (65Zn) for microplastic radiotracer model. After a stability study in seawater, phosphate buffer saline (PBS), and human serum albumin (HSA) for fifteen days, PSM-131I remained stable (>90 %), except in HSA (50–60 % after day-9), while PSM-65Zn was unstable (<50 %).

Comparative Review of the Current and Future Strategies to Evaluate Bone Marrow Infiltration at Diffuse Large B-Cell Lymphoma Diagnosis.

Diffuse large B-cell lymphoma (DLBCL) requires a complete staging at diagnosis that may have prognostic and therapeutic implications. The role of bone marrow (BM) biopsy (BMB) is controversial in the era of nuclear imaging techniques. We performed a comparative review of 25 studies focused on BM evaluation at DLBCL diagnosis, including at least two of the following techniques: BMB, flow cytometry, and positron emission tomography (PET-FDG). The report about BM involvement (BMi), diagnostic accuracy, and prognostic significance was collected and compared among techniques. A concordance analysis between BMB, FCM, and PET was also performed, and we deeply evaluated the implications of the different types of BMi: concordant by LBCL or discordant by low-grade B-cell lymphoma for both BMB and FCM, and focal or diffuse uptake pattern for PET. As a main conclusion, BMB, FCM, and PET are complementary tools that provide different and clinically relevant information in the assessment of BMi in newly diagnosed DLBCL.

Effect of Gamma Irradiation on Embryogenic Calli of Rice and Subsequent Shoot and Regeneration

This study was carried out during May 2021 to January 2022 at the Tissue Culture Laboratory of Biotechnology Division, Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh, Bangladesh for callus induction and regeneration ability of plantlet from low doses irradiated embryogenic calli of Binadhan-13 and BR5 (Dulabhog). The effect of low gamma rays such as 4, 6 and 8 Gy were observed in vitro shoot, root and plantlet formation. Two different incubation conditions such as light and dark incubation were maintained. Between two varieties, Binadhan-13 showed the highest ability of callus induction in both conditions. Callus induction was significantly higher under dark condition (77.14%) than light condition (67.14%) ‍at 21 days. Data revealed that gamma rays affect both shoot and root regeneration ability of embryogenic callus. Shoot regeneration ability was the highest at 4 Gy in Binadhan-13 (60%) and gradually decreased with the increased doses of gamma rays. Among the treatments, shoot regeneration ability (60% in Binadhan-13 and 50% in BR5) was higher at 4 Gy dose of gamma ray followed by 6 Gy where shoot regeneration ability was 55% and 45% in Binadhan-13 and BR5 respectively. In root induction, the highest root induction ability (80%) was observed in the cultivar Binadhan-13 at control condition. Like shoot regeneration, 4 Gy gamma ray showed better root induction in both the varieties (70% in Binadhan-13, 60% in BR5). The in vitro regenerated plantlets from irradiated embryogenic calli were successfully transferred to soil in pots. The regeneration protocol could be further used for varietal improvement of rice varieties using nuclear technique (60Co gamma ray). Bangladesh J. Nuclear Agric, 37(2): 29-42, 2023

The impact of phosphate fertilizer factory on the chemical and radiological pollution of the surrounding marine area (seawater and sediments) in northwestern Greece

Phosphogypsum, a waste of phosphate fertilizers production, contains heavy metals and especially radionuclides as 238U, 226Ra and 232Th. It is usually deposited in stacks close to coastal zones and the leachates with seawater result in chemical and radiological pollution. In this work the pollution in the coastal environment surrounding a phosphate fertilizer factory in northwestern Greece was investigated by measuring the activity of radionuclides (238U, 226Ra and 232Th) and the concentrations of heavy metals (Pb, Zn, Cu, Ni, Cd and As) in seawater and sediments samples. The measurements were performed by nuclear spectrometry and chemical techniques in two seasons and radiation risks were estimated, by determination of indexes asRaeq, Hin, Hex and Iγ as well as absorbed dose rate D. The values were in the range of worldwide indicating low hazard. Moreover, several environmental indicators (HPI, MPI, CF, Cd and EF) were applied to evaluate the water and sediment quality for heavy metal contamination and the average concentrations of the investigated heavy metals, showed that there is no danger for humans.

Diagnostic Approaches in Nuclear Medicine for Reproductive Health Assessment: Hysterosalpingography in Radiology versus hysterosalpingoscintigraphy.

Infertility is a significant aspect of reproductive health and evaluating degree of tubal pathology is essential for determining appropriate management plans. To assess the role of hysterosalpingoscintigraphy (HSSG) as a tubal patency test in nuclear medicine and compare it with hysterosalpingography (HSG) in radiology in infertile women and study pain perception in both tests as well. A prospective study was conducted on 50 infertility patients undergoing infertility evaluation at a tertiary care hospital. Both HSG and HSSG procedures were performed during proliferative phase of menstrual cycle. Our study demonstrated the potential of HSSG as a tool for evaluating tubal patency in infertility workup. It showed good accuracy in detecting tubal patency compared to HSG. HSG is a radiological procedure valued for its ability to provide detailed anatomical information of uterus and patency of fallopian tubes. In contrast, HSSG provides dynamic information on the functional aspects of the reproductive system using nuclear medicine techniques. Both HSG and HSSG are vital tools in the diagnostic armamentarium for assessing female reproductive health, offering complementary information that aids in comprehensive patient management.

Microscopic and Macroscopic Characterization of Hydrogels Based on Poly(vinyl-alcohol)-Glutaraldehyde Mixtures for Fricke Gel Dosimetry.

In recent decades, hydrogels have emerged as innovative soft materials with widespread applications in the medical and biomedical fields, including drug delivery, tissue engineering, and gel dosimetry. In this work, a comprehensive study of the macroscopic and microscopic properties of hydrogel matrices based on Poly(vinyl-alcohol) (PVA) chemically crosslinked with Glutaraldehyde (GTA) was reported. Five different kinds of PVAs differing in molecular weight and degree of hydrolysis were considered. The local microscopic organization of the hydrogels was studied through the use of the 1H nuclear magnetic resonance relaxometry technique. Various macroscopic properties (gel fraction, water loss, contact angle, swelling degree, viscosity, and Young's Modulus) were investigated with the aim of finding a correlation between them and the features of the hydrogel matrix. Additionally, an optical characterization was performed on all the hydrogels loaded with Fricke solution to assess their dosimetric behavior. The results obtained indicate that the degree of PVA hydrolysis is a crucial parameter influencing the structure of the hydrogel matrix. This factor should be considered for ensuring stability over time, a vital property in the context of potential biomedical applications where hydrogels act as radiological tissue-equivalent materials.

Application of internal mono standard neutron activation analysis method in elemental analysis of car glasses for forensic study

The use of nuclear techniques for elemental analysis has been successfully developed in many laboratories in the IAEA Member States, including Vietnam. Nuclear techniques have also been proven to be extremely powerful in provenancing samples relevant to forensics. In the framework of the CRP project on Enhancing Nuclear Analytical Techniques to Meet the Needs of Forensic Sciences (IAEA CRP F11021), a total of 19 elemental concentrations in 48 car glass samples has been determined by the internal monostandard neutron activation analysis (IM-NAA) method. In this work, obtained results from the statical analysis indicated that rare earth elements (La, Ce, Sm, Eu, Tb, Yb), transition (Sc, Mn, Fe, Co, Zn) and major (Al, Na, Fe, Ca) elements play a significant role in the group study of car glasses.

Evaluating sustainability of Bhuj aquifer system, Western India using nuclear dating techniques

Abstract Increasing population, food demands and climatic stressors pose an imminent threat to groundwater sustainability in regional aquifer systems globally. Limited availability of surface water and erratic/uncertain rainfall necessitates preservation of groundwater resources, which form reliable fresh water reserves in most of the arid regions. Bhuj Sandstone aquifer is one such fresh groundwater systems in Western India catering the domestic/irrigational needs for over 2 million population. Rapid groundwater depletion in this area warranted a mandatory conservation of groundwater resources for future sustainability. Nuclear techniques using 3H and 14C provide estimates of groundwater age that help in planning sustainable groundwater management. In this study, sustainability of deep groundwater was assessed using environmental radioactive isotopes (3H, 14C). Results indicate that 14C activity of the groundwater samples varies from 26 to 73.6 pMC (percent modern carbon). Considering the various biases and uncertainties present, multiple correction models were applied to obtain representative groundwater ages by incorporating stable (13C) isotope and hydrogeochemical data. The corrected and representative ages are found to range from 5.8 to 8.6 ka BP (thousand years before present). From the study it can be inferred that central Bhuj aquifer hosts paleo-groundwater while the western part is recently recharged. Therefore, over-exploitation of deep groundwater in central Bhuj aquifer may further lower the water levels and this would have long-term impact on the socio-economic development of Kutch region.

Cardiovascular risk factors and development of nomograms in an Italian cohort of patients with suspected coronary artery disease undergoing SPECT or PET stress myocardial perfusion imaging.

Single-photon emission computed tomography (SPECT) and positron emission tomography (PET) are non-invasive nuclear medicine techniques that can identify areas of abnormal myocardial perfusion. We assessed the prevalence of cardiovascular risk factors in patients with suspected coronary artery disease (CAD) undergoing SPECT or PET stress myocardial perfusion imaging (MPI). Based on significant risk factors associated with an abnormal MPI, we developed a nomogram for each cohort as a pretest that would be helpful in decision-making for clinicians. A total of 6,854 patients with suspected CAD who underwent stress myocardial perfusion imaging by SPECT or PET/CT was studied. As part of the baseline examination, clinical teams collected information on traditional cardiovascular risk factors: age, gender, body mass index, angina, dyspnea, diabetes, hypertension, hyperlipidemia, family history of CAD, and smoking. The prevalence of cardiovascular risk factors was different in the two cohorts of patients undergoing SPECT (n = 4,397) or PET (n = 2,457) myocardial perfusion imaging. A statistical significance was observed in both cohorts for age, gender, and diabetes. At multivariable analysis, only age and male gender were significant covariates in both cohorts. The risk of abnormal myocardial perfusion imaging related to age was greater in patients undergoing PET (odds ratio 4% vs. 1% per year). In contrast, male gender odds ratio was slightly higher for SPECT compared to PET (2.52 vs. 2.06). In the SPECT cohort, smoking increased the risk of abnormal perfusion of 24%. Among patients undergoing PET, diabetes and hypertension increased the risk of abnormal perfusion by 63% and 37%, respectively. For each cohort, we obtained a nomogram by significant risk factors at multivariable logistic regression. The area under the receiver operating characteristic curve associated with the nomogram was 0.67 for SPECT and 0.73 for the PET model. Patients with suspected CAD belonging to two different cohorts undergoing SPECT or PET stress myocardial perfusion imaging can have different cardiovascular risk factors associated with a higher risk of an abnormal MPI study. As crude variables, age, gender, and diabetes were significant for both cohorts. Net of the effect of other covariates, age and gender were the only risk factors in common between the two cohorts. Furthermore, smoking and type of stress test were significant for the SPECT cohort, where as diabetes and hypertension were significant for the PET cohort. Nomograms obtained by significant risk factors for the two cohorts can be used by clinicians to evaluate the risk of an abnormal study.

Simulator Education Initiatives for On-Campus Practical Training in Nuclear Medicine Technology.

Because nuclear medicine diagnostic equipment has not been installed at our educational institution, we had not been able to incorporate nuclear medicine techniques into on-campus training until now. Methods: We have introduced a diagnostic image processing simulator to replace nuclear medicine diagnostic equipment. The simulator was used to conduct on-campus practical training on nuclear medicine technology. We also conducted a questionnaire survey of students regarding their experience with on-campus practical training using the simulators. Results: The survey results revealed that the on-campus practical training using simulators deepened students' understanding of the content they had encountered in classroom lectures. Conclusion: We successfully implemented on-campus practical training in nuclear medicine technology using a diagnostic image-processing simulator. According to the results of our questionnaire, it is possible to provide on-campus practical training to students using simulators that enhance understanding of nuclear medicine technology.

19F Nuclear Magnetic Resonance Fingerprinting Technique for Identifying and Quantifying G-Quadruplex Topology in Human Telomeric Overhangs.

G-quadruplexes (G4s) are noncanonical nucleic acid secondary structures with diverse topological features and biological roles. Human telomeric (Htelo) overhangs consisting of TTAGGG repeats can fold into G4s that adopt different topologies under physiological conditions. These G4s are potential targets for anticancer drugs. Despite intensive research, the existence and topology of G4s at Htelo overhangs in vivo are still unclear because there is no method to distinguish and quantify the topology of Htelo overhangs with native lengths that can form more than three tandem G4s in living cells. Herein, we present a novel 19F chemical shift fingerprinting technique to identify and quantify the topology of the Htelo overhangs up to five G-quadruplexes (G4s) and 120 nucleotides long both in vitro and in living cells. Our results show that longer overhang sequences tend to form stable G4s at the 5'- and 3'-ends, while the interior G4s are dynamic and "sliding" along the sequence, with TTA or 1-3 TTAGGG repeats as a linker. Each G4 in the longer overhang is conformationally heterogeneous, but the predominant ones are hybrid-2, two- or three-tetrad antiparallel, and hybrid-1 at the 5'-terminal, interior, and 3'-terminal, respectively. Additionally, we observed a distinct behavior of different lengths of telomeric sequences in living cells, suggesting that the overhang length and protein accessibility are related to its function. This technique provides a powerful tool for quickly identifying the folding topology and relative population of long Htelo overhangs, which may provide valuable insights into telomere functionality and be beneficial for structure-based anticancer drug development targeting G4s.