Gamma-ray Research Articles

Study on the Effect of Adipose Tissue on Neutron Dose Evaluation for the Human Body Using Voxel Phantoms with Different Weight

Abstract When human body is irradiated by neutrons, the adipose content has a significant impact on the neutron dose and induced 24Na activity. To investigate the effect of human adipose content on the conversion coefficients from 24Na activity to neutron dose, five male adult reference computational phantoms with weights ranging from 73.5 kg to 136.5 kg were used. The Monte Carlo N-particle (MCNP) code was used to calculate the neutron absorbed dose and the yield of induced 24Na in the phantoms irradiated by 252Cf neutrons and monoenergetic neutrons. The results showed that the difference in the conversion coefficients from 24Na activity to neutron absorbed dose among the five phantoms irradiated by 252Cf neutrons with anterior posterior (AP) geometry was ≤23.30%, and this difference was attributed mainly to the neutron absorbed dose, which increases with increasing adipose content. Considering the self-absorption of gamma rays in the human body, the counts of 24Na characteristic gamma rays measured directly by the radiation detector outside of the body have no significant trend varying with adipose content, and the difference in the conversion coefficients from the measured counts to neutron dose among the five phantoms irradiated by 252Cf neutrons with AP geometry was ≤5.25%.

Technical note: Effects of chemical, radiational, and thermal treatment of bone tissue on material stiffness and anisotropy.

We evaluated the effects of four treatments for pathogen inactivation in bone tissue (ethanol storage, formalin fixation, gamma irradiation, and heat treatment via autoclave) on stiffness and anisotropy values in bone samples. Cortical bone samples from the humerus of 14 bovine specimens were subjected to Knoop microindentation analysis in longitudinal and transverse planes of section and four indenter orientations within each section. From each specimen, individual samples were assigned to one of five treatment conditions: 50% ethanol-saline solution, formalin immersion, gamma irradiation, autoclave, and buffered saline (controls). Each sample was microindented 100 times and the resultant stiffness data were analyzed by a resampled factorial analysis of variance. First- and second-order interactions as well as main effects of indenter orientation, treatment, and specimen were significant for both transverse and longitudinal sections, with the sole exception that indenter orientation-treatment interaction was nonsignificant for longitudinal sections. Interaction plots reveal that thermal (autoclave) and irradiation treatments depress stiffness values the most, while patterns of indentation stiffness at different orientations are relatively unaffected. Patterns of anisotropy are relatively unaffected by preservative treatments, but elastic modulus changes are consistent and unambiguous. Formalin and ethanol treatments are most comparable to controls and represent the best preservative media for mechanical testing. These options, however, are likely to be the least effective for ensuring the inactivation or sterilization of potentially contaminated samples.

Genetic and phytochemical evaluation of M2 generation mutants of fenugreek (Trigonella foenum-graecum L.) induced by gamma rays and Ethyl Methane Sulphonate (EMS).

Fenugreek (Trigonella foenum-graecum L.) is highly esteemed for its therapeutic properties and is widely used in traditional medicine and modern pharmacology. Enhancing its genetic traits and phytochemical profile, particularly its trigonelline content, can significantly increase its medicinal and agricultural value. This study aims to investigate the effects of gamma rays and Ethyl Methane Sulphonate (EMS) as mutagenic agents on the genetic and phytochemical characteristics of the M2 generation of fenugreek, focusing on genetic diversity and desirable trait enhancement. To achieve this, various concentrations of EMS and gamma rays were administered to fenugreek seeds, and 27 traits were assessed in the resulting M2 generation. These traits were analyzed for variance, mean values, and correlations. The genetic diversity of 23 M2 offspring was investigated using nine Start Codon Targeted (SCoT) markers. The genetic diversity assessment involved Principal Coordinate Analysis (PCoA) and cluster analysis, utilizing the Dice similarity coefficients and the Unweighted Pair Group Method with Arithmetic Mean (UPGMA). A Bayesian model provided deeper insights into the genetic structure. Results revealed that lower doses of gamma rays (100Gy) and EMS (0.2%) positively impacted specific traits. In comparison, higher doses (200Gy and 0.4% EMS) increased seed trigonelline content to 0.71mg/g dry weight. Among the SCoT markers, SCoT-9 was the most efficient, segregating the populations into three clusters. The first three principal components in the PCoA explained 20% of the total variance, leading to seven subgroup populations distinction. These findings underscore the potential of induced mutagenesis in enhancing desirable traits in fenugreek.

Mutation induction by gamma rays in clonal plantlets of Eucalyptus saligna and Eucalyptus dunnii: dose adjustment and application of repeated pruning

Mutation induction by gamma rays in clonal plantlets of Eucalyptus saligna and Eucalyptus dunnii: dose adjustment and application of repeated pruning

Possible existence of dose-rate threshold for mutation induction by chronic low-dose-rate gamma-rays.

To assess the biological effects of low-dose and low-dose-rate radiation, we established a sensitive assay system for detecting somatic mutations in hypoxanthine-phosphoribosyltransferase 1 (HPRT1) gene. In this study, we investigated the dose-rate effects of mutagenesis by gamma irradiation at dose-rates of 6.6, 20 and 200mGy d-1. We identified a potential inflection point in the gamma-induced mutant frequency, which ranged between 6.6 and 20mGy d-1. In addition, the mutant spectrum was not different from that of the non-irradiated control at all dose-rates. Compared with previous studies with low-concentration HTO exposure, mutant frequencies were similar, but mutant spectrum showed different trends, especially at high-dose-rates (200mGy d-1). These observations indicate the presence of potential mechanistic differences in mutagenic events between tritium beta and gamma-rays.

Valery Aleksandrovich Chereshnev – organizer of the immunological service in the Western Urals

The article is dedicated to the 80th anniversary of Valery Aleksandrovich Chereshnev, a Russian scientist, academician of the Russian Academy of Sciences, known for his works in the field of immunology and pathophysiology. V.A. Chereshnev began his career at Perm State Medical Institute, where he continued his postgraduate studies after graduating with honors. In 1970, he defended his PhD thesis on the topic “On the role of the properties of microbial cells and macroorganisms in the mechanism of development of an early phagocytic reaction to the introduction of typhoid vaccine”. In 1982, he defended his doctoral dissertation on the topic “Closed chest injury in combination with gamma irradiation (clinic, pathogenesis, treatment, medical protection).” He worked as a lecturer and professor in various educational institutions, and also headed scientific laboratories. In 1988, he became the director of the Institute of Ecology and Genetics of Microorganisms, Ural Branch of the Russian Academy of Sciences, and then organized a branch in Yekaterinburg, which was later transformed into the Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, where he also became the director. Valery Aleksandrovich was elected a corresponding member of the Russian Academy of Sciences, academician of the Russian Academy of Sciences, Chairman of the Ural Branch of the Russian Academy of Sciences and Vice-President of the Russian Academy of Sciences, Chairman of the Committee on Science and High Technologies of the State Duma of the Federal Assembly of the Russian Federation. In addition, he was elected President of the Russian Scientific Society of Immunologists, organized the Society of Immunologists of the Urals. Currently he is actively developing immunological services in the Western Urals.

Effect of tin oxide particle size on epoxy resin to form new composites against gamma radiation.

The aim of the present study is to assess the shielding performance of a novel lead-free epoxide material against ionizing radiation. The effect of variation in particle size and concentration of tin oxide (SnO), which was added to epoxy resin polymer (ER), on its radiation shielding properties has been investigated in this research. Ten samples of ER samples incorporated with different concentrations (0%,20%,40%,60%) of SnO microparticles, nanoparticles, and both sizes combined were prepared and assessed. The linear attenuation coefficients (LAC) were measured experimentally through the collimated gamma-ray beam at 0.0595MeV, 0.6617MeV, 1.1730MeV, and 1.330MeV emitted from Am-241, Cs-137 and Co-60, respectively (to cover all energy range of gamma rays) for all samples with various concentrations and particle sizes of SnO. The other radiological shielding parameters such as half value layer (HVL), tenth value layer (TVL), and radiation protection efficiency (RPE) were estimated and compared for all different samples. The results prove that the increasing of the concentration and reducing the particle size of SnO leads to the enhancement of the radiation protection properties of the ER polymer. Moreover, it was observed that the incorporation of SnO micro- and nanoparticles together improves the radiation shielding properties of ER samples. Conclusively, the reinforcing of ER polymer material matrix by micro/nanoparticles of SnO as composite with enhanced radiation shielding specifications was highlighted.

Construction of a realistic voxel phantom of the Japanese red fox (Vulpes vulpes japonica) based on MRI imaging and estimation of its background external radiation dose rate from environmental radionuclides.

In this study, we selected the Japanese red fox (Vulpes vulpes japonica) as a representative mid-size mammal from the forests near the spent nuclear fuel reprocessing plant at Rokkasho. A fox voxel phantom was constructed based on magnetic resonance imaging of a female red fox caught in Rokkasho. This phantom consisted of 264×321×383 voxels (each voxel size: 0.78×0.78×2mm) with internal organs. The external radiation dose rate to the voxel phantom by beta and gamma rays from environmental radionuclides was estimated using a Monte Carlo code (EGS4 and UCPIXEL). We estimated the dose rates to the phantom on the ground and in an average fox burrow in the Rokkasho forest, which were 11 and 27 nGy h-1, respectively. Assuming that the animal on the ground was irradiated by cosmic rays of 27 nGy h-1, the total external dose rate was evaluated to be 38 nGy h-1. Based on the assumption that the fox lives on the ground for 12h and in the burrow for 12h, the dose rate was estimated to be 33 nGy h-1.

Induced genetic variability for quantitative and biochemical traits of local landraces of rajmash (Phaseolus vulgaris) of north-western Himalayas

The present study was carried out during rainy (kharif) seasons of 2020 and 2021 at Regional Horticulture Research Station (Sher-e-Kashmir University of Agricultural Sciences and Technology, Jammu, Jammu and Kashmir), Bhaderwah, Doda, Jammu, Jammu and Kashmir to evaluate genetic variability for quantitative and biochemical traits of local landraces of rajmash (Phaseolus vulgaris L.) of north-western Himalayas. Twenty-two induced mutant lines of rajmash generated with gamma rays and ethyl methane sulphonate were screened for quantitative, qualitative and anthracnose reactions under natural and artificial conditions in the field during kharif 2020 (M3) and 2021 (M4). The highly significant differences imply that induced mutant lines for different traits exhibited substantial amount of genetic diversity. Zinc content (55.38) and grain yield/plant (33.24) both had high phenotypic coefficients of variation, while 1000-seed weight (10.14) and protein content had low values (9.83). Zinc content had highest genetic advance, measured as a percentage of the mean, and the highest heritability, followed by grain yield/plant, iron content, number of pods/plant, number of clusters/plant, days to flowering and number of seeds/pod, whereas days to maturity and 1000-seed weight were moderate. The number of pods/plant (0.774), number of seeds/pod (0.556), number of clusters/plant (0.729), length of pod (0.648) and 1000-seed weight (0.620) all exposed a highly significant relationship with grain yield/plant but the days to flowering (-0.636) and days to maturity showed negative correlation (-0.602). It is obvious that the 9 induced mutant lines of Bhaderwah local and Poonch local i.e. R-BL-M3-1, R-BL-M3-9, R-BL-M3-10, R-BL-M3-12, R-BL-M3-13, R-BL-M3-14, R-PL-M3-18, R-PL-M3-20 and R-PL-M3-22 showed the minimum anthracnose disease incidence along with early emergence and superiority in grain yield/plant compared to controls. These mutant lines may be carried forward for the development of mutant genetic stocks and varietal development programmes of rajmash for north-western Himalayan region.

The effects of antioxidant administration in the early stages of radiation-induced tumorigenesis.

ApcMin/+ mouse was a model mouse for human familial adenomatous polyposis, and irradiation at an early age increases tumors in the small and large intestine. To study the effects of antioxidant administration on tumor incidence after continuous whole-body exposure to gamma rays, ApcMin/+ mice were exposed to a medium-dose-rate, 200mGy/d, from postnatal Day 0 to 21 of age or a high-dose-rate of 0.65Gy/min (total dose 4.2Gy) on postnatal Day 7. The dams and pups were supplied with the N-acetylcysteine (NAC) in drinking water (7g/L), from gestation Day 15 until weaning (21days-old). A significant increase in the number of intestinal tumors were observed in ApcMin/+ mice irradiated with high dose-rate gamma rays as compared with the non-irradiated controls, but there was no significant difference in tumor counts between the non-irradiated controls and the medium-dose rate irradiation groups. NAC administration did not have any significant effect at least at this dose. These results suggest that the supplementation of anti-oxidant at the early stage of tumorigenesis does not suppress the formation of irradiation-induced small intestinal tumors.

Discerning TGF and Leader Current Pulse in ASIM Observation

AbstractTerrestrial gamma ray flash (TGF) observations made by the Atmosphere‐Space Interaction Monitor (ASIM) have demonstrated that these TGFs are accompanied by a prominent optical pulse from a hot leader channel. It is hard to confidently resolve the true sequence of the events in the source region due to temporal proximity of the involved processes. Here we report a bright long duration TGF together with its associated optical recordings showing clear temporal separation between the TGF and the optical pulse. In this observation the optical pulse is clearly distinct and subsequent relative to the TGF. The corresponding lightning discharge occurred at the very end of the TGF. We conclude that the current surge inside the lightning leader channel cannot be responsible for generation of this TGF. The current surge that produced the associated optical pulse can itself be conditioned by the TGF and may be responsible for the TGF termination.

ESR measurement of carbonated hydroxyapatite for dosemeter.

We have examined a dosimetry characteristic of carbonate hydroxyapatite (CO3HAp), which is a dental bone graft material. The purpose of this work is to investigate the reproducibility and stability of radiation-induced radicals on CO3HAp samples and assess the feasibility of using these materials as dosemeters. CO3HAp samples were exposed to gamma rays with dose range from 10 to 10000Gy. The electron spin resonance (ESR) spectra for irradiated samples were measured. Variation of peak-to-peak amplitude of the ESR signal intensity as a function of absorbed dose for CO3HAp was compared with that for alanine dosemeters, suggesting that the CO3HAp sample has a good linear dose response in the range from 10to 10000Gy as well as does the alanine dosemeters.

Proton bunch monitors for the clinical translation of prompt gamma-ray timing

Objective. Prompt gamma-ray timing is an emerging technology in the field of particle therapy treatment verification. This system measures the arrival times of gamma rays produced in the patient body and uses the cyclotron radio frequency signal as time reference for the beam micro-bunches. Its translation into clinical practice is currently hindered by observed instabilities in the phase relation between the cyclotron radio frequency and the measured arrival time of prompt gamma rays. To counteract this, two proton bunch monitors are presented, integrated into the prompt gamma-ray timing workflow and evaluated.Approach. The two monitors are (a) a diamond detector placed at the beam energy degrader, and (b) a cyclotron monitor signal measuring the phase difference between dee current and voltage. First, the two proton bunch monitors as well as their mutual correlation were characterized. Then, a prompt gamma-ray timing measurement was performed aiming to quantify the present magnitude of the phase instabilities and to evaluate the ability of the proton bunch monitors to correct for these instabilities.Main results. It was found that the two new monitors showed a very high correlation for intermediate proton energies after the first second of irradiation, and that they were able to reduce fluctuations in the detected phase of prompt gamma rays. Furthermore, the amplitude of the phase instabilities had intrinsically decreased from about 700 ps to below 100 ps due to cyclotron upgrades.Significance. The uncertainty of the prompt gamma-ray timing method for proton treatment verification was reduced. For routine clinical application, challenges remain in accounting for detector load effects, temperature drifts and throughput limitations.

A study of nuclear radiation interaction parameters of some plant based radio-protective compounds

In radiation therapy, various radioprotective materials protect normal cells from the damage produced by ionizing radiation. Plant-based chemical compounds possess antioxidant properties and can scavenge free radicals produced by nuclear radiation. Determining radiation shielding parameters and understanding how nuclear radiation interacts with plant-based radioprotectors are crucial for choosing the optimal plant-based radioprotectors. In the present work, the interaction of gamma, neutron, electron, proton, and alpha particles with plant-based radioprotectives such as ferulic acid, genistein, hesperidin, lycopene, psoralidin, sesamol, troxerutin, vanillin, and zingerone has been studied. The interaction parameters such as MAC, Z eff , EBF, and EABF for gamma energy, MAF for thermal and fast neutrons, and MSP for electrons, protons, and alpha have been calculated for the plant-based radioprotectors using the software EpiXs, PyMLBUF, NGCal, ESTAR, PSTAR, and ASTAR. Results show that genistein and lycopene show high and low effective atomic numbers in the higher energy region of gamma photons, respectively. The neutron mass attenuation factor is found to be highest for lycopene and lowest for genistein for both thermal and fast neutrons. Among the selected plant-derived radioprotectives, troxerutin and lycopene are the most effective plant-based compounds for gamma and neutron radiation therapy applications. The shielding parameters of selected plant-based radioprotector materials are compared with those of some chemical radioprotectors. Besides, the shielding parameters of selected plant-based radioprotector materials are comparable to chemical radioprotectors except for lycopene.

NEW APPROACHES TO CROSSLINKING IN COMBINATION WITH REFRACTIVE KERATOMODELING IN CORNEAL ECTASIA

Objective: To consider new approaches to crosslinking in combination with refractive keratomodeling in corneal ectasia of various etiologies.Methods: The work is based on clinical observations of the immediate and remote results of prophylactic and therapeutic corneal crosslinking with argon-fluorine excimer laser radiation (over 700 operations) over periods from 1 month to 13 years. Particular emphasis was placed on the formation of a Bowman-like membrane structure on the ablation surface and local exposure with a personalized gradient refractive profile of the total dose of radiation to achieve a greater keratomodeling effect. Rapid transition without additional calibrations to energy densities below the ablation threshold was carried out on the Russian excimer laser “Microscan Visum-500”.Results: Experimental and clinical studies have shown that excimer laser radiation on argon-fluorine can be used for corneal crosslinking, with energy densities in the pulse being below the ablation threshold. The advantage of excimer laser crosslinking was scanning with a narrow beam, which disrupts the oxygenation of the corneal stroma to a lesser extent and allows for the implementation of personalized local refractive keratomodeling based on keratotopography or aberrometry data. In this case, the induced secondary radiation covers all four peaks of maximum absorption by riboflavin. The use of subablative energy densities during irradiation of the cornea in the personalized PRK mode made it possible to locally affect the ectasia zone and enhance the refractive effect due to the gradient distribution of the total radiation dose.Conclusion: Radiation from an argon-fluorine excimer laser opens up new possibilities for refractive ablative and non-ablative refractive keratomodeling of the cornea in combination with laser-induced crosslinking in keratoconus and secondary keratoectasias of various etiologies.

Latent characterisation of the complete BATSE gamma ray bursts catalogue using Gaussian mixture of factor analysers and model-estimated overlap-based syncytial clustering

Abstract Characterising and distinguishing gamma-ray bursts (GRBs) has interested astronomers for many decades. While some authors have found two or three groups of GRBs by analyzing only a few parameters, recent work identified five ellipsoidally-shaped groups upon considering nine parameters T50, T90, F1, F2, F3, F4, P64, P256, P1024. Yet others suggest sub-classes within the two or three groups found earlier. Using a mixture model of Gaussian factor analysers, we analysed 1150 GRBs, that had nine parameters observed, from the current Burst and Transient Source Experiment (BATSE) catalogue, and again established five ellipsoidal-shaped groups to describe the GRBs. These five groups are characterised in terms of their average duration, fluence and spectrum as shorter-faint-hard, long-intermediate-soft, long-intermediate-intermediate, long-bright-intermediate and short-faint-hard. The use of factor analysers in describing individual group densities allows for a more thorough group-wise characterisation of the parameters in terms of a few latent features. However, given the discrepancy with many other existing studies that advocated for two or three groups, we also performed model-estimated overlap-based syncytial clustering (MOBSynC) that successively merges poorer-separated groups. The five ellipsoidal groups merge into three and then into two groups, one with GRBs of low durations and the other having longer duration GRBs. These groups are also characterised in terms of a few latent factors made up of the nine parameters. Our analysis provides context for all three sets of results, and in doing so, details a multi-layered characterisation of the BATSE GRBs, while also explaining the structure in their variability.

Chronic bronchitis and bronchial asthma: the impact of chronic occupational radiation exposure on incidence and mortality of Mayak nuclear workers.

The information about the radiation risk of non-cancer respiratory diseases is inconsistent and mainly corresponds to mortality. Previously, an increased risk of chronic bronchitis incidence was demonstrated in the cohort of workers employed at the first Russian nuclear facility Mayak Production Association who had been chronically exposed to gamma rays (externally) and to alpha-active plutonium aerosols (internally). Within this retrospective study, we performed analyses of incidence of and mortality from chronic bronchitis and bronchial asthma using improved estimates of radiation doses provided by the "Mayak Worker Dosimetry System (MWDS) - 2013". The cohort included 22,377 individuals hired in 1948-1982, and its follow-up was extended by 10 years (to the end of 2018). The excess relative risk of chronic bronchitis incidence per unit radiation dose (ERR/Gy) and the 95% confidence interval (95% CI) were: with the 0-year lag ERR/Gy=0.07 (95% CI -0.01, 0.17) for gamma exposure and ERR/Gy=0.36 (95% CI 0.13, 0.68) for alpha exposure; with the 10-year lag ERR/Gy=0.15 (95% CI 0.04, 0.30) for gamma exposure and ERR/Gy=0.54 (95% CI 0.19, 1.03) for alpha exposure. The chronic bronchitis mortality risk was significantly associated with internal alpha exposure only for certain worker categories: ERR/Gy=4.08 (95% CI 0.59, 14.3) in males; ERR/Gy=7.10 (95% CI 0.31, 70.44) in former smokers; ERR/Gy=7.94 (95% CI 1.71, 30.2) in workers with the smoking index above 20 pack×years. No association was observed in the chronic bronchitis mortality risk with external gamma exposure. No strong evidence was observed for the impact of gamma and alpha exposure on risk of mortality from chronic bronchitis. The study confirmed the significant positive linear association of the chronic bronchitis incidence risk with gamma and alpha radiation doses from occupational chronic external and internal exposure. However, the estimates of ERR/Gy of alpha particles from internal exposure appeared to be almost 2.4-3 times lower than those based on the MWDS-2008. The observed inconsistency requires further clarification. As for bronchial asthma in Mayak workers, no association was demonstrated in the incidence and mortality risks with occupational gamma and alpha radiation exposure.

Irradiated whole cell Chlamydia vaccine confers significant protection in a murine genital tract challenge model.

Chlamydia trachomatis infections are the most common bacterial STIs globally and can lead to serious morbidity if untreated. Development of a killed, whole-cell vaccine has been stymied by coincident epitope destruction during inactivation. Here, we present a prototype Chlamydia vaccine composed of elementary bodies (EBs) from the related mouse pathogen, Chlamydia muridarum (Cm). EBs inactivated by gamma rays (Ir-Cm) in the presence of the antioxidant Mn2+-Decapeptide (DEHGTAVMLK) Phosphate (MDP) are protected from epitope damage but not DNA damage. Cm EBs gamma-inactivated with MDP retain their structure and provide significant protection in a murine genital tract infection model. Mice vaccinated with Ir-Cm (+MDP) exhibited elevated levels of Cm-specific IgG and IgA antibodies, reduced bacterial burdens, accelerated clearance, and distinctive cytokine responses compared to unvaccinated controls and animals vaccinated with EBs irradiated without MDP. Preserving EB epitopes with MDP during gamma inactivation offers the potential for a polyvalent, whole-cell vaccine against C. trachomatis.

Isolation and characterization of gamma rays induced mutants for improved agro-morphological performance and harder grain texture in wheat (Triticum aestivum L.)

Purpose Kernel texture plays a principal role in determining technological flour properties and end-use quality of wheat products. Hence, a multi-year mutation induction programme was conducted to isolate advanced wheat mutant lines with agro-morphologically superior performance, higher disease resistance and harder grain texture. Materials and methods Radiation mutagenesis was employed in soft textured wheat variety HPW 89 using gamma rays dose of 250, 300 and 350 Gy (Co60: BARC, Mumbai) and evaluated across M1–5 generations. Promising superior mutants selected were evaluated during M4 and M5 generation for induced variability and trait association for agro-morphological and quality traits. The screened mutants were also determined for induced changes at genetic level using gene specific markers for puroindoline genes. Results A total of 293 agro-morphologically superior mutants isolated showed significant genetic variation in the M4 generation. Single kernel characterization system categorized 267 mutants (8.79–50.06) with higher grain hardness than the HPW 89 variety (7.39). Among these, 108 mutants were selected for agro-morphological and molecular characterization. Significant variations were found in these mutants in either pina and pinb or both puroindoline genes. Clustering among these mutants led to the formation of five clusters and a total of eleven mutants were found with better set of agro-morphological, disease resistance and quality traits. Conclusion These mutants can serve as important genetic resource for developing harder texture bread wheat varieties in the future grain quality improvement programmes. These mutants will also bridge the need of bakers and millers’ requirement of varieties with specific texture and quality.

Ionizing Radiation Dose to the Skin Assessed after Rapid Detection of 232Th in Consumer Products.

After some consumer products indicated elevated levels of 232Th progeny by gamma-ray spectrometry, a microwave digestion and inductively coupled plasma-mass spectrometry (ICP-MS) procedure was implemented for the direct assay of 232Th content to ensure compliance with Federal regulations and guidelines. Levels of 232Th were determined by ICP-MS based on standard calibration using a 205Tl internal standard. The method had a method detection limit (MDL) of 0.15 Bq g-1 and a lower limit of quantification (LLOQ) of 0.65 Bq g-1 for 232Th, making it a suitable confirmatory method following gamma-ray spectrometry. The 232Th activity concentration calculated from the ICP-MS results ranged from 2.0-3.4 Bq g-1 for the kinesiology tape samples and 20 Bq g-1 for the silicone ion bracelet. The VARSKIN+1.0 software program was used to calculate the shallow dose equivalent of ionizing radiation from 232Th and its progeny from the ICP-MS results. The skin dose to the consumer wearing the kinesiology tape ranged from 0.48-1.6 mSv y-1. The skin dose to the consumer with constant wear of the silicone ion bracelet was estimated to be 17 mSv y-1. Although 232Th may be determined indirectly by assay of high abundance gamma rays produced by its progeny, the US Code of Federal Regulations (CFR) requires the direct assay of 232Th for confirmatory analysis. We found this ICP-MS method to be a rapid 232Th confirmatory technique compared to a chemical separation followed by alpha spectrometry procedure.