60Co Irradiation Research Articles

Study of a gel dosimeter based on Ag nanoparticles for applications in radiation therapy with synchrotron X-rays at ultrahigh dose rate compared to 60Co γ-rays

A silver nitrate (AgNO3) gel was developed and evaluated as a dosimeter for synchrotron X-ray-based studies in microbeam radiation therapy (MRT) and FLASH radiation therapy. The gel was irradiated at the European Synchrotron Radiation Facility (ID17 Biomedical beamline) with a continuous X-ray spectrum in the 50-600 keV range and a dose rate of 11.6kGy/s. The spectrophotometric response after irradiation at this beamline was compared with the response at a conventional 60Co γ-ray source providing a dose rate of 0.27 Gy/s. Ag+ ions in the gel dosimeter undergo reduction to Ago nanoparticles, as detected at 450 nm, which is a surface plasmon resonance band. The intensity of this band increased linearly with increasing absorbed dose up to 100 Gy, and improved with the addition of glycerol. The gel dosimeter exhibited the lowest detectable dose (LDD) of 75.9% lower and a dose deposition of 76% higher for ID17 beamline irradiation than for 60Co irradiation. The theoretical relative response HQ,Qo for the gel irradiated at the synchrotron was 1.70, which is in close agreement with the experimental relative response FQ,Qo = 1.76. These results confirm the dose enhancement in the gel irradiated with orthovoltage X-rays. The good properties of the silver nitrate gel, together with its increased sensitivity to orthovoltage X-ray irradiation and modest overall uncertainty of 5.8% (2σ), confirm that the gel is a valid dosimeter for measurements at ultrahigh dose rates for synchrotron radiotherapy. The dosimeter is also a promising candidate for dose enhancement factor measurements in nanoparticle-based radiotherapy techniques.

One pot gamma radiation mediated interfacial engineering of P-N synergistic flame retardant and antibacterial cellulose fabric: novel fabrics for future applications

AbstractThe work describes an ionizing radiation mediated, toxic solvent free interfacial engineering of a novel Phosphorus-Nitrogen functionalized bifunctional cotton cellulose fabric (BCF) endowed with flame retardant (FR) and antibacterial properties. Monomers bis[2-(methacryloyloxy)ethyl] phosphate (B2MEP) and [2-(methacryloyloxy)ethyl]trimethylammonium chloride (MAETC) in different proportions were co-grafted onto cellulose fabric via 60Co radiation mediated Simultaneous Irradiation Grafting Process (SIGP) to incorporate Phosphorus and Nitrogen functionalities. Effects of radiation dose, monomer concentration on the grafting yield (GY) were investigated and samples were characterized using TGA, ATR-FTIR, XRD, SEM–EDX, EDXRF, CHN Elemental Analysis and XPS analytical techniques. Limiting oxygen index (IS:13501/ASTM D 2863) and vertical flammability tests (IS11871-1986) were conducted to establish the halogen free, P-N synergistic FR properties of the fabric. All the co-grafted samples were observed to possess LOI values in excess of 30%, while BCF (1:2) (GY = ~ 44%) demonstrated LOI of 32% with the least char length of 74 mm in the vertical flammability tests. Tear strength studies were carried out as per ASTMD 1424-09. Antibacterial assay revealed that the fabric possessed activity against both gram positive (S. aureus) and gram negative (E. coli) organisms, with BCF (1:4) (GY = ~ 48%) demonstrating complete killing of ~ 5 log cycles for both microorganisms in 24 h. BCF retained its FR and antibacterial properties even after multiple washing cycles. With its bonafide green credentials, durability and unique properties, multifunctional BCF fabric prepared under optimized conditions of P/N ratio > 1.7 and GY ~ 45% can be a potential candidate for future applications.

Synthesis of Activated Carbon from Banana Peel Biomass Using NaCl and Gamma Co-60 Irradiation

Abstract Indonesian Institute of Sciences (LIPI) stated that the potential for biomass resources in Indonesia is estimated at 49,810 MW originating from plants and waste in 2013 and of course it continues to grow, considering that the source of biomass is from nature. An example of biomass is banana peel. This banana peel can be used as activated carbon. Known from several journals that activated carbon can be applied in various ways such as being a hydrogen storage material, water purification, etc. There are three steps to synthesis activated carbon that divided into initial steps, the first is synthesis of activated carbon, which begins with drying banana peels and then cutting them, then drying them below the sun. Then it is carbonized at 400°C and immersed chemically activated with a salt activator, NaCl. The second step is combining or modifying activated carbon via gamma irradiation and the last step is characterization using BET to know surface area and FTIR to analyze the functional group. The result shows that as an effect of the modification of gamma irradiation doses by 10 kGy, 30 kGy and 50 kGy on activated carbon banana peel, the FTIR spectra increased markedly by the widening of the last stretch. Modification the banana peel with gamma irradiaton Co-60 is the surface area is increase than those without irradiation, but not significantly. It occurred due to the process of carbon degrade due to gamma irradiation of Co-60 can degrade cellulose structures.

Modification of activated carbon through chemical-physical activation method with KOH and 60Co gamma irradiation from banana leaf waste

Abstract Until now waste is still a problem in many big cities in Indonesia. In addition, the amount of waste increases as the population increases. Banana leaf waste is no exception, which is included in other types of waste, which accounts for 6.33% of the total waste in Indonesia in 2022. Utilization of banana leaf waste as a raw material for activated carbon production can also be an alternative to reducing the amount of wasted banana leaf waste because they contain various kinds of organic compounds. Activated carbon is widely used as an adsorbent in various sectors, especially in the industrial sector. Production of activated carbon must go through an activation process to enlarge the surface pores either chemically or physically, or even both. This study aims to compare the results of activated carbon surface area and functional groups using the chemical-physical activation method from banana leaf biomass raw materials with KOH and gamma irradiation at various doses. The research method used is an experimental method consisting of 4 stages: dehydration, carbonization, activation, and characterization. The research was started by dehydrating the leaves and continued with the carbonization stage at 350°C for 30 minutes. Carbon was divided into four samples that consisted of 1 blank and 3 test materials that activated with 30% (w/v) KOH solution for 24 hours and gamma-irradiated with a dose of 10, 30, and 50 kGy. Results were characterized using FTIR and BET. The effect of gamma 60Co irradiation on the activated carbon material from banana leaf waste can increase the peak transmittance value of the activated carbon functional group due to the formation and reaction of free radicals on its surface. Increase in the surface area (from 6.504 to 24.04 m2/g) is also associated with an increase in the absorbed dose due to the formation of more free radicals. However, the surface area obtained is not as expected due to the possibility of pore blockage and excessive activation time, which causes the surface area of the material to be small.

Total Ionizing Dose and Single-Event Effect Response of the AD524CDZ Instrumentation Amplifier

This manuscript focuses on studying the radiation response of the Commercial-off-the-shelf (COTS) AD524CDZ operational amplifier. Total Ionizing Dose (TID) effects were tested using low-dose 60Co irradiation. Single-Event Effect (SEE) sensitivity was studied on this operational amplifier using a 105 MeV proton beam. Additionally, further study of the SEE response was carried out using a Two-photon absorption laser to scan some sensitive sectors of the die. For this laser experiment, different gain setups and laser energies were employed to determine how the Single Event Transient (SET) response of the device was affected based on the test configuration. The results from the TID experiments revealed that the studied device remained functional after 100 krads (Si). Proton experiments revealed the studied device exhibited a high SET response with a maximum DC offset SET of about 1.5 V. Laser experiments demonstrated that there was a clear SET reduction when using 10× and 1000× gain setups.

Co60 May be the Acceptable Alternative Radionuclides of Ir192 used in HDR Brachytherapy for the Treatment of Inoperable Carcinoma Cervix in the Treatment Modality of Concurrent Chemoradiation

Background: Cancer of the uterine cervix is the eighth most common cancer among women worldwide and third among all malignancies and the second most common cancers in female in Bangladesh. The treatment of cervical cancer requires multidisciplinary approaches Concurrent chemoradiation is the treatment of choice in locally advanced carcinoma cervix uteri. Radiotherapy is the primary local treatment for most patients having FIGO stage IIB to IVA diseases. The success of treatment depends on a careful balance between EBRT and Brachytherapy that optimizes the dose to tumor. Iridium192 is highly used radionuclide for modern remote after loading HDR brachytherapy till date. Recently Co60 source is available with miniature size and identical physical properties for remote after loaders. Methods: 60 patients with biopsy proven locally advanced carcinoma of the uterine cervix were enrolled in the study. Arm A was formed comprising 30 patients who were treated by Ir192 HDR brachytherapy and Arm B formed with equal number of 30 patients who received HDR brachytherapy treated with Co60 radionuclide. This prospective observational study was carried out to compare the treatment effect between two Arm. Results: 60 patients were enrolled in this study with age range from 35 to 63 years. Most of the patients presented with stage IIB disease, consisting of 39 patients (65.3%). Among them 48 patients had squamous cell carcinoma (80.60%), adenocarcinoma trailing with 9 patients (15.3%) and rest were adenoidsquamous carcinoma 2 and small cell carcinoma. In all three insertions, urinary bladder dose distribution was slightly smaller by HDR Co60 irradiation than HDR Ir192 exposure. These differences were statistically significant in first two insertions but not in third one Conclusion: In this study radiation dose distribution at OARs i.e. urinary bladder and rectum were compared between Arm A and Arm B. In all three insertions in urinary bladder the mean dose distribution was slightly smaller in HDR Co60 irradiation than HDR Iridium192 exposure. These differences were statistically significant in first two insertions but not in third one. In case of rectum point, the mean dose distribution was significantly lower in all three insertions of Co60 exposure than Ir192 exposure.

Documents to procure gamma irradiation chamber and license for operation in blood center

Abstract: Graft-versus-host disease is a critical posttransplant complication, particularly affecting individuals with compromised immune systems. Patients undergoing bone marrow transplants, neonates receiving intrauterine transfusions, and those recipients of blood from first-degree relatives are vulnerable to this condition. The significance of efficient lymphocyte inactivation has driven the widespread adoption of Gamma Irradiation Chambers (GICs) utilizing radiation sources such as Cesium-137 (Cs-137) or Cobalt-60 (Co-60). However, the effective operation of these chambers is contingent on navigating a complex regulatory landscape (Cs-137 or Co-60 is commonly used as the source of gamma rays. The usual dose is 25 Gray [Gy] to 35 Gy [1 Gy = 100 rads], this dosage inactivates 85%–95% of lymphocytes in the blood components without any adverse effect on other cellular components of the blood). GIC unit mainly houses either Co-60 or Cs-137as radiation sources (model no BI-2000, BI-5000 mfr. by Board of Radiation and Isotope Technology with typical radioactivity ranging from tens to hundreds of terabecquerel. These units are also used in research institutions, hospitals, blood center, etc. A review of legal, regulatory, and policy aspects of the operation of GIC in India regarding its issues, challenges, and opportunities. We aimed to prepare a standard guidance document for GIC for a smooth process of the Atomic Energy Regulatory Board (AERB) licensing and equipment purchasing. The present article was written based on the experience of applying for GIC with AERB and recurrent support extended to colleagues in the fraternity. The documents prepared for licensing and various procedural steps involved in the same are included. Many documents and many days are required from procurement to the receipt of the license for operation GIC. At the same time, with very few user institutes and less number of experienced people in the country, it becomes difficult to find a proper method to approach the national government body. If blood center/radiological safety officer are properly trained as per the guidelines available, this can reduce man-days and facilitate the earliest operations.

Characterization of diamond and organic scintillation detectors utilizing radiation sources for continuous plasma operation.

This paper provides a comprehensive study of neutron calibration methodologies, specifically highlighting the capabilities for n-γ discrimination in diamond and EJ-309, and stilbene scintillation detectors. The calibration process detailed in this study includes pulse height analysis and pulse shape discrimination, relying on the analysis of charge deposition resulting from both γ and neutron interactions. Utilizing 60Co and 252Cf radiation sources, the energy spectra of these sources are obtained. The characterized detectors were used in ST40 experiments and allowed acquiring neutron signal during a plasma shot with good agreement among diamond and scintillation detectors. Then, the diamond detector was cross-calibrated against indium activation foils placed at the same location in proximity to the ST40 during plasma shots: both detectors measured a neutron flux of ≈106 cm-2 s-1 at ≈1 m distance from the tokamak center, and the discrepancy between the diamond detector and the activation foils is ≈25%.

Numerical modeling of total dose effects on CD4007 MOSFET during switched-bias irradiation

The response of commercial-off-the-shelf CD4007 p-channel MOSFET exposed to 60Co radiation under switched-bias conditions is studied by real time monitoring the threshold voltage evolution with accumulated dose. The possibility to employ switched-bias techniques to recover threshold voltage is demonstrated. As reported for other devices, non-monotonic responses are observed. A physics-based numerical model that takes into account both charge buildup within the oxide and generation of interface traps is employed to reproduce the experimental results. The implications for dosimetry are discussed.

Development of plastic scintillator with better performance than the commercial counterpart (UPS-923A) and effect of fluorophore composition on light output

In this study we have synthesized polystyrene based plastic scintillators (PS) loaded with commercially available fluorophores like p-Terphenyl and 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP). Optimum concentration of the fluorophores in the synthesized PS was determined. The PS exhibited 1.55 ± 0.05 times better light output than UPS-923A, a commercial PS. Emission maxima were obtained at 423 nm with an energy linearity of 99.78% up to 1.061 MeV. Radiation damage of PS by Co-60 irradiation led to 22.3% loss of light yield at 50 kGy radiation dose which is better than the commercial one. The loss of light output in the PS due to radiation damage was because of the degradation of polystyrene matrix rather than the fluorophores.

Functional Analysis of Stress Resistance of Bacillus cereus SCL10 Strain Based on Whole-Genome Sequencing.

A Gram-positive, rod-shaped, aerobic, motile, and spore-forming bacterium, designated SCL10, was isolated from Acaudina molpadioides exposure to Co-60 radiation. In this study, whole-genome sequencing was performed to identify the strain as Bacillus cereus and functional characterization, with a focus on stress resistance. The genome of the B. cereus SCL10 strain was sequenced and assembled, revealing a size of 4,979,182 bp and 5167 coding genes. The genes involved in biological functions were annotated by using the GO, COG, KEGG, NR, and Swiss-Prot databases. The results showed that genes related to alkyl hydroperoxide reductase (ahpC, ahpF), DNA-binding proteins from starved cells (dps), spore and biofilm formation (spoVG, spo0A, gerP), cold shock-like protein (cspC, cspE), ATP-dependent chaperone (clpB), and photolyase, small, acid-soluble spore protein (SASP) and DNA repair protein (recA, radD) could explain the stress resistance. These findings suggest that antioxidant activity, sporulation, biofilm formation, and DNA protection may be considered as the main resistance mechanisms under exposure to radiation in the B. cereus SCL10 strain.

Synthesis of conducting polymer by gamma Co-60 ray in aqueous solution

This report presents the findings of a study on the synthesis of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) using gamma Co-60 radiation in an aqueous solution saturated with N2 gas, containing 5 mM EDOT monomer and 0.2 M isopropanol. Gamma radiation with doses ranging from 12 kGy to 58 kGy from a gamma Co-60 source was employed. To assess the chemical composition of the solution before and after irradiation, UV-Vis and FTIR absorption spectra were examined. The results indicated the formation of yellow suspensions in the solution after irradiation, along with the emergence of dimers, oligomers, and PEDOT polymers as evidenced by UV-Vis spectra. The dried powders obtained from the irradiated solutions confirmed the successful synthesis of PEDOT, exhibiting distinct chemical structural characteristics in the FTIR spectra. These findings demonstrate the effective radiation-induced synthesis of conducting PEDOT polymer using gamma Co-60 irradiation.

Monitoring for Actinide Neutron Emissions From Spent Nuclear Fuel Under Extreme Gamma Fields Using Centrifugally Tensioned Metastable Fluid Detector Sensor Technology

Abstract This paper presents outcomes from research studies conducted independently at Purdue University as part of a collaborative project with the staff of Pacific Northwest National Laboratory (PNNL). Research work focused on assessments for meeting the challenge of monitoring actinide content in spent nuclear fuel (SNF) via characteristic neutron emissions [from spontaneous fission and (α,n) reactions] using the centrifugally tensioned metastable fluid detector (CTMFD) sensor technology using an inert organic decafluoropentane (DFP)(C5H2F10) sensing fluid. Traditional detectors readily saturate and/or cannot monitor neutron emissions under the expected 1012:1 gamma to neutron radiation environment. A challenge problem was posed to examine if a CTMFD could operate reliably over 1 h for conducting neutron spectroscopy at a 1 m standoff from a 30-y cooled SNF, in a ∼1012:1 gamma:neutron intensity environment resulting in a 150 Gy (15 kRad) accumulated dose for the CTMFD. The impacts on reliable operability were studied separately under expected gamma radiation energy and intensity for possible effects of: (i) radiolysis in the CTMFD sensing fluid from absorbed (<1.5 MeV) gamma radiation; (ii) photoneutron contamination signals from < 3 MeV high energy gamma photons interacting with the sensing fluid; and, (iii) malfunction of CTMFD component electronics from the absorbed gamma radiation. A Co-60 gamma irradiator was used for dose accumulation in the CTMFD electronic components and sensing fluids. A 14 MeV DT accelerator was used with a NaCl target to produce 3–4 MeV photons from activated 37S (via. neutron absorption in 37Cl) at SNF-commensurate intensities from SNF at 1-m standoff. Our examinations revealed the absence of any significant impact on CTMFD performance for meeting and exceeding the challenge problem metric. That is, we validated for no discernible impact of: 3–4 MeV gamma-produced photoneutrons when combined with a fission neutron source and radiolysis in the DFP sensing fluid through a 150 Gy absorbed dose. Past research results at Purdue University have validated for survivability of the key electronic components for absorbed gamma doses above the targeted 150 Gy level. This paper also provides extended evidence for survivability (from radiolysis) at higher gamma doses through 750 Gy with a borated DFP-sensing fluid formulation-based CTMFD.

An Evaluation of the Impact of 60Co Irradiation on Volatile Organic Compounds of Olibanum Using Gas Chromatography Ion Mobility Spectrometry.

Olibanum is a resinous traditional Chinese medicine that is directly used as a powder. It is widely used in China and is often combined with other traditional Chinese medicine powders to promote blood circulation and relieve pain, as well as to treat rheumatism, rheumatoid arthritis, and osteoarthritis. Powdered traditional Chinese medicine is often easily contaminated by microorganisms and 60Co irradiation is one of the good sterilization methods. Volatile organic compounds (VOCs) are the main active ingredient of olibanum. The aim of this study was to validate the optimum doses of 60Co irradiation and its effect on VOCs. 60Co irradiation was applied in different doses of 0 kGy, 1.5 kGy, 3.0 kGy, and 6.0 kGy. Changes in VOCs were detected using gas chromatography ion mobility spectrometry. A total of 81 VOCs were identified. The odor fingerprint results showed that, with an increase in irradiation dose, most of the VOCs of olibanum changed. Through principal component analysis, cluster analysis, and partial least squares discriminant analysis, it was demonstrated that, at 1.5 kGy, the impact of radiation on the VOCs of olibanum was minimal, indicating this is a relatively good irradiation dose. This study provides a theoretical basis for the irradiation processing and quality control of resinous medicinal materials such as olibanum and it also provides a good reference for irradiation technology development and its application to functional foods, thus making it both significant from a research perspective and useful from an application perspective.

CACNA1B protects naked mole-rat hippocampal neuron from apoptosis via altering the subcellular localization of Nrf2 after 60Co irradiation.

Although radiotherapy is the most effective treatment modality for brain tumors, it always injures the central nervous system, leading to potential sequelae such as cognitive dysfunction. Radiation induces molecular, cellular, and functional changes in neuronal and glial cells. The hippocampus plays a critical role in learning and memory; therefore, concerns about radiation-induced injury are widespread. Multiple studies have focused on this complex problem, but the results have not been fully elucidated. Naked mole rat brains were irradiated with 60Co at a dose of 10 Gy. On 7 days, 14 days, and 28 days after irradiation, hippocampi in the control groups were obtained for next-generation sequencing. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were subsequently performed. Venn diagrams revealed 580 differentially expressed genes (DEGs) that were common at different times after irradiation. GO and KEGG analyses revealed that the 580 common DEGs were enriched in molecular transducer activity. In particular, CACNA1B mediated regulatory effects after irradiation. CACNA1B expression increased significantly after irradiation. Downregulation of CACNA1B led to a reduction in apoptosis and reactive oxygen species levels in hippocampal neurons. This was due to the interaction between CACNA1B and Nrf2, which disturbed the normal nuclear localization of Nrf2. In addition, CACNA1B downregulation led to a decrease in the cognitive functions of naked mole rats. These findings reveal the pivotal role of CACNA1B in regulating radiation-induced brain injury and will lead to the development of a novel strategy to prevent brain injury after irradiation.

Rearing and 60Co radiation do not affect attractiveness but alter the volatile profiles released by Anastrepha obliqua calling males.

Calling males of Anastrepha obliqua release volatile compounds to attract conspecific males to form leks and females to mate. Male volatiles from Mexican and Brazilian populations of A. obliqua have been previously identified. However, there are differences in the number and identity of volatile compounds between the populations. These differences in volatile profiles may be due to male origin (e.g. wild or mass-reared flies) or methodological issues (e.g. sampling techniques). In this study, we evaluated the attractiveness of wild, laboratory non-irradiated, and laboratory-irradiated flies under semi-field conditions. Male volatiles were collected using dynamic headspace sampling (DHS) and solid-phase microextraction (SPME) techniques, and identified using gas chromatography-coupled mass spectrometry. The results showed no difference in the attractiveness of wild, laboratory non-irradiated, and irradiated males to females. However, the number of captured females differed according to the origin; wild and non-irradiated females were captured more frequently than the irradiated flies. A total of 21 compounds were found using SPME, whereas only 12 were collected using DHS, although the relative amounts of these compounds were higher than those obtained using the former sampling technique. In addition, only laboratory non-irradiated males released α-pinene and menthol, which have not been previously reported in this fruit fly species. Additionally, we identified novel compounds in A. obliqua; however, certain compounds previously reported were not detected. This study suggests that despite the qualitative and quantitative variations in the volatile profiles of A. obliqua males, their attractiveness was unaffected.

Radiation-hard performance research of front-end electronics for fusion diagnostic by Gamma Irradiation Experiment

In the environment of a fusion reactor, electronic systems are subjected to various influences including vibration, electromagnetic pulses, as well as irradiation from neutrons and gamma rays. Diagnostics systems on fusion reactors can accumulate radiation doses to a level where issues such as signal attenuation and system interruption can occur. Additionally, maintenance of electronic systems during fusion reactor experiments is often not feasible. Therefore, assessing the radiation tolerance of electronic systems used in fusion reactors is of paramount importance. To validate the radiation resistance of front-end electronics and cable in various diagnostic systems, a test circuit board was designed. This board integrates a variety of commonly used amplification chips and power supply chips to assess their performance in the environment of a fusion reactor. The experiment selected three different types of cables commonly used in fusion reactors for separate testing, to assess their parameter changes before and after irradiation experiments. Gamma Irradiation Experiments were conducted using a cobalt-60 (Co-60) radiation source at the Irradiation Center of Nanjing University of Aeronautics and Astronautics. The test circuit board was exposed to continuous gamma irradiation at two test points, with dose rates of 6 Gy/min and 1 Gy/min, respectively, for a total of 6.5 h, Data from the irradiation experiments were collected and analyzed. The results show that under continuous gamma irradiation, CJ7805 and AMS1117–5 chips stopped working at 586 Gy and 776 Gy, respectively. The output of the LT1175I5 chip dropped from -5 V to -1 V at 447 Gy. Apart from the radiation-resistant power supply chips, the output of other power supply chips slightly decreased. The signal reference of the charge amplifier dropped at 741 Gy but then slowly rose again, and the signal amplitude decreased at 900 Gy. The signal reference of the current amplification circuit remained unchanged, with a slight decrease in amplitude. The signal reference of the voltage amplifier exhibited jitter, with no change in amplitude. The experiment provides valuable data support for the radiation-resistant design of electronic systems in the environment of a nuclear fusion reactor.

Analysis of the effect of 60Co irradiation sterilization on the chemical composition of volatile organic compounds in Rhizoma Acori Tatarinowii using GC-IMS

The volatile organic compounds (VOCs) of Rhizoma Acori Tatarinowii were extracted via steam distillation and then irradiated with 60Co-γ rays, in which doses of 60Co-γ 0, 5, and 10 kGy were selected to irradiate the VOCs. Finally, gas chromatography–ion mobility spectrometry (GC-IMS) was used to compare the differences between the VOCs, and then qualitatively analyse the components and contents of each part of the VOCs The results showed that under the three irradiation doses of 60Co-γ 0, 5 and 10 kGy, the VOCs of unirradiated and 5 kGy-irradiated samples were closer, and the samples irradiated at a 10 kGy dose were quite different from the other two components, meaning that when the calamus medicinal materials were sterilised by means of 60Co irradiation, the dose of 5 kGy was closer to the original compound content of the medicinal materials.

Gamma Irradiation Doses reduce Cooking time and Improve Nutritional Profile of selected Pigeon pea [Cajanus cajan (L.) Millsp] Genotypes in Nigeria

Pigeon Pea (Cajanus cajan L.) is a self-pollinating perennial legume shrub with over 30,000 accessions deposited world-wide. Despite the nutritional importance of pigeon peas, its detrimental traits such as its long cooking time, has led to low cultivation of the crop and inhibit its consumers’ request. Concerted efforts to improve both the quality and quantity of this crop through mutation breeding informed this research. It was based on this premise that the study was aimed to evaluate gamma irradiation influences on the nutrient quality and cooking duration of selected pigeon pea varieties in Nigeria. Four accessions of pigeon peas (‘NG/SA/11/08/108’, ‘NG/AO/MAY/00/021/01’, ‘TCC-2’ and ‘NG/SA/07/191’) were obtained from National Centre for Genetic Resources and Biotechnology (NACGRAB), Ibadan. They were irradiated at the Oncological Department ABU Teaching Hospital, Shika, Zaria, using Cobalt-60 (60CO) irradiation source. Standard procedures were followed to determine the effects of the irradiation on cookability and nutritional profile of the M1 plants and their respective controls. It was established that all the parameters tested were irradiation dose dependent. In NG/AO/MAY/00/021/01, 100 Gy produced the highest protein (20.40 %) and highest carbohydrate (68.93 %) contents. Anti-nutritional factors such as cyanide were lower (48.83, 46.22, 43.65 and 44.75 mg/kg in NG/AO/MAY/00/021/01, NG/SA/11/08/108, NG/SA/07/191 and TCC-2) at 400 Gy than those of their respective controls (54.83, 56.83, 53. and 53.55 mg/kg). The amount of Magnesium increased with higher doses of gamma irradiation (1.37 g/100 g for 200 Gy NG/AO/MAY/00/021/01; 1.03 g/100g for 400 Gy NG/SA/11/08/108 and 1.13 g/100 g for TCC-2). There were significant reductions in cooking time in 400 Gy treatments for all the genotypes. The differences between the control and the least cooking time in 400 Gy were 11, 16, 22 and 15 minutes for NG/AO/MAY/00/021/01, NG/SA/11/08/108, NG/SA/07/191 and TCC-2, respectively. It was therefore concluded that these variations could be exploited for further improvement of the crop for food security. Keywords: Cooking time, Mutation breeding, Gamma irradiation, Cookability, Dose dependent

Investigation of the Suitability of Different Materials as Human Tissue Simulating Materials in Co-60 Radiation Energy Beam

Radiotherapy calibration for precise dose delivery traditionally relies on water phantom systems, but this approach poses challenges of heterogeneous corrections or the use of anthropomorphic phantoms which most underdeveloped nations find expensive. In this study, the suitability of some tissue simulating materials were investigated within the Co-60 photons energy range. This study explores the identification of locally sourced materials to simulate human tissue behavior in Co-60 energy beams. By considering effective atomic numbers and physical densities, we evaluate materials for simulating soft tissue, lung, and bone. Water, aluminum metal, and polystyrene (Styrofoam) were selected for simulating soft tissue, bone, and lung, respectively, due to their close radiological properties, availability, and affordability. This research provides valuable insights for resource-constrained regions aiming to improve radiotherapy calibration methods.