• Title/Summary/Keyword: uptake of radionuclides

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Current status of research on radionuclides used in nuclear mediccine (중성자선 실험 및 발암연구의 현황과 미래)

  • Kim, Hui-Seon
    • Radioisotope journal
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    • v.21 no.3
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    • pp.46-60
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    • 2006
  • In recent years the progress of nuclear medicine advanced dramatically in imaging and targeted radionuclide therapy is able to open op exciting perspectives as standard diagnostic and therapeutic modalities, complementing conventional modalities. Positron emission tomography/computed tomography (PET/CT) technology with FDG has been developed clinically in less than 10 years as a routine standard in oncological imaging, including a number of other fluorinated radiopharmaceuticals being evaluated for their ability to complement FDG. However, the limitation of FDG-PET such as non-specific uptake and its short half-life is not compatible with the time necessary for optimal tumour targeting. Therefore, a development of innovative positron-emitting radionuclides with half-lives longer than 10 h is needed. For therapeutic applications, the injection of higher activities is required to reach efficient adsorbed doses in radioresistant solid tumours, while limiting the irradiation of vital organs. In this application, the longer half-life of radiolsotopes are more fit well for radionuclide therapy. To achieve this, researches have to be carried in a largor spectrum of radionuclides for diagnosis and therapy. In the context of rapidly growing nuclear medicine and strong demanding innovative radionuclides, a high-energy (100 MeV), high-intensity (-mA) accelerator with proton (PEFF at KAFRI). will be operating in 2011. The priorities of PEFP will include supporting the nuclear medicine research community by providing those radionuclides with current limited availability by means of a high-energy, high-intensity accelerator.

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Uptake of Radionuclides by Some Fungi

  • Mahmoud, Yehia A.G.
    • Mycobiology
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    • v.32 no.3
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    • pp.110-114
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    • 2004
  • Mycobiota including Alternaria alternata, Fusarium verticillioides and Aspergillus pulverulents were tested for their ability to uptake radiocobalt(Co-60) and radiocesium(Cs-137) from radionuclide containing medium. A. alternata was the most efficient fungal species for uptake of radioisotopes, followed by A. pulverulents, whereas F. verticilliodies came in the last rank. The conditions of radioisotope uptake were optimized such as the form of the fungal organism either spores or mycelium, inoculum age and pH of growing medium. Furthermore the total pigments of the tested fungi were extracted and tested for their ability to bind with radioisotope, where melanin of A. alternata produced about 60% for radioisotope uptake out of total added radioisotope radioactivity. Moreover, transmission electron microscopic examination of radioisotope exposed spores showed high precipitation of melanin granules in the spore wall and within the cell as comparing to untreated spores.

Occurrence of Vesicular-Arbuscular Mycorrhizal (VAM) Fungi and Their Effect on Plant Growth in Endangered Vegetations

  • Selvaraj, Thangaswamy;Padmanabhan, Chellappan;Jeong, Yu-Jin;Kim, Hoon
    • Journal of Microbiology and Biotechnology
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    • v.14 no.4
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    • pp.885-890
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    • 2004
  • A survey for vesicular-arbuscular mycorrhizae (VAM) occurrence was undertaken in three endangered vegetation sites in the area of Kudankulam atomic power station. Fifteen VAM fungal species were isolated from the root-zone soils of fourteen different plant species. There was a significant correlation observed between the number of spores and of percentage root colonization as exemplified by Phyllanthus niruri and Paspalum vaginatum (450, 95%; 60, 25%). Although VAM species are not known to be strictly site specific, the fact that Acaulospora elegans was observed only in site 1, Glomus pulvinatum in site 2 only, and Gl. intraradices in site 3 only, showed site-specificity in this study. To confirm the infection efficiency, two host plant species in the sites, P. niruri and Eclipta alba, were selected and inoculated in field with three selected VAM fungal spores. Gl. fasciculatum was found to be the most efficient VAM species in percentage root colonization, number of VAM spores, and dry matter content. When the nutrients in roots of P. niruri and E. alba were analyzed, there was higher uptake of K (4.2 and 3.4 times, respectively) and Ca (5.3 and 4.9 times, respectively), the analogues for $^{137}Cs$ and $^{90}Sr$, respectively. From the results, it might be concluded that VAM association helps the plants survive in a disturbed ecosystem and enhances uptake and cycling of radionuclides from the ecosystem.

Review of Radionuclide Treatment for Neuroendocrine Tumors (신경내분비종양의 방사성핵종 치료)

  • Jeong, Hwan-Jeong
    • Nuclear Medicine and Molecular Imaging
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    • v.40 no.2
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    • pp.90-95
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    • 2006
  • Neuroendocrine tumors (NETs) consist of a heterogeneous group of tumors that are able to uptake neuroamine and/or specific receptors, such as somatostatin receptors, which can play important roles of the localization and treatment of these tumors. When considering therapy with radionuclides, the best radioligand should be carefully investigated. $^{131}I$-MIBG and beta-particle emitter labeled somatostatin analogs are well established radionuclide therapy modalities for NETs. $^{111}In,\;^{90}Y\;and\;^{177}Lu$ radiolabeled somatostatin analogues have been used for treatment of NETs. Further, radionuclide therapy modalities, for example, radioimmunotherapy, radiolabeled peptides such as minigastrin are currently under development and in different phases of clinical investigation. for all radionuclides used for therapy, long-term and survival statistics are not yet available and only partial tumour responses have been obtained using $^{131}I$-MIBG and $^{111}In$-octreotide. Experimental results using $^{90}Y$-DOTA-lanreotide as well as $^{90}Y-DOTA-D-Phe1-Tyr^3-octreotide$ and/or $^{177}Lu-DOTA-Tyr^3-octreotate$ have indicated the possible clinical potential of radionuclides receptor-targeted radiotherapy it may be hoped that the efficacy of radionuclide therapy will be improved by co-administration of chemotherapeutic drugs whose antitumoral properties may be synergistic with that of irradiation.

Estimation of radiostrontium, radiocesium and radiobarium transfer from arid soil to plant: A case study from Kuwait

  • Aba, Abdulaziz;Ismaeel, Anfal;Al-Boloushi, Omar
    • Nuclear Engineering and Technology
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    • v.53 no.3
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    • pp.960-966
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    • 2021
  • A technical approach to design and carry out an experiment to determine the uptake of selected radionuclides in site-specific conditions in Kuwait was developed and successfully executed for developing a radioecological decision support system. The radionuclides from soil-to-plant transfer factors have been obtained for leafy and non-leafy vegetables, and root crops cultivated in Kuwait. Two types of vegetated soils were selected and spiked with high concentrations of three relatively short-lived selected radionuclides (85Sr, 134Cs, and 133Ba). The highest strontium and barium transfer factors were found in the order: leafy vegetables > root crops > non-leafy vegetables. The approximate range of radiocesium transfer factor was found to be low in all plant groups and was comparable to those reported elsewhere in different soil types of temperate and tropical environments. A strong negative correlation between the obtained transfer factors and the distribution coefficient of the radionuclide in soil was found. It is recommended to adopt the newly derived parameters for the sensitive areas in Kuwait and other Gulf countries instead of using the generic parameters, whenever dose calculation codes are used. This will help to more accurately assess and predict the end results of the committed effective dose equivalent through ingestion pathway.

An Overview of Phytoremediation Technology and Its Applications to Environmental Pollution Control (식물정화기술의 개요와 환경오염 제어에의 응용 현황)

  • Lee, Jae Heung
    • KSBB Journal
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    • v.27 no.5
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    • pp.281-288
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    • 2012
  • Phytoremediation-the use of plants for the in situ treatment of contaminated soil and water-has recently emerged as an inexpensive and user-friendly alternative to traditional methods of environmental clean-up. The present article outlines the characteristics of phytoremediation based on accumulated research evidence, along with discussions on its advantages and disadvantages. It further reviews various mechanisms involved in the phytoremediation processes: phytoextraction, rhizofiltration, phytostabilization, phytovolatilization and phytodegradation. Along the way, the author summarizes examples of its applications to environmental pollution control. These include wastewater treatment, removal of heavy metals, and hydrocarbons, remediation of recalcitrant contaminants, phytoremediation of radionuclides, and application of transgenic plants for enhanced biodegradation and phytoremediation. The remainder of the article briefly concludes with directions for future research.

Influence of Ectomycorrhizal Colonization on Cesium Uptake by Pinus densiflora Seedlings

  • Ogo, Sumika;Yamanaka, Takashi;Akama, Keiko;Nagakura, Junko;Yamaji, Keiko
    • Mycobiology
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    • v.46 no.4
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    • pp.388-395
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    • 2018
  • Radionuclides were deposited at forest areas in eastern parts of Japan following the Fukushima Daiichi Nuclear Power Plant incident in March 2011. Ectomycorrhizal (EM) fungi have important effects on radiocaesium dynamics in forest ecosystems. We examined the effect of colonization by the EM fungus Astraeus hygrometricus on the uptake of cesium (Cs) and potassium (K) by Pinus densiflora seedlings. Pine seedlings exhibited enhanced growth after the EM formation due to the colonization by A. hygrometricus. Additionally, the shoot Cs concentration increased after the EM formation when Cs was not added to the medium. This suggests that A. hygrometricus might be able to solubilize Cs fixed to soil particles. Moreover, the shoot K concentration increased significantly after the EM formation when Cs was added. However, there were no significant differences in the root K concentration between EM and non-EM seedlings. These results suggest that different mechanisms control the transfer of Cs and K from the root to the shoot of pine seedlings.

Model for Transport of Accidently Released Radionuclides onto Rice-Fields and its Comparison with Experimental Data (사고시 논으로 유출된 핵종 이동 모델 및 실험결과와의 비교)

  • Keum, Dong-Kwon;Lee, Han-Soo;Choi, Heui-Joo;Kang, Hee-Suk;Lim, Kwang-Muk;Choi, Young-Ho;Lee, Chang-Woo
    • Journal of Radiation Protection and Research
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    • v.29 no.2
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    • pp.117-127
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    • 2004
  • A dynamic compartment model was developed to evaluate the transport of accidently released radionuclides onto rice-fields. In the model, the surface water compartment and shoot-base absorption were introduced to account for the effect of irrigation, which is essential to a rice cultivation. The soil mixing by plough and irrigation before transplanting rice was also considered, and the rate of root-uptake and shoot-base absorption were modeled in terms of the function of biomass. In order to test the validation of the model, it was applied to the analysis of some simulated $^{137}Cs$ deposition experiments that were performed while cultivating rice in a greenhouse using soils sampled from rice-fields around Kori, Yonggwang and Ulchin nuclear power plants. The model prediction was generally agreed within about one order of magnitude with experimental data.

Assessment of Absorbed Dose of by Organ according to Thyroidal Uptake of Radioactive Iodine for Adult Korean Males (한국성인 남성을 대상으로 한 방사성옥소의 갑상선 섭취율에 따른 각 장기별 흡수선량 평가)

  • Kim, Junghoon;Lim, Changseon;Whang, Jooho
    • Progress in Medical Physics
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    • v.18 no.4
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    • pp.187-193
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    • 2007
  • In an effort to assess the internal absorbed dose of radionuclides that is suitable to Koreans' physiological characteristics, we asked 28 male Koreans to take $^{131}|$ orally, determined the thyroidal uptake and daily urination ratio, and assessed the absorbed dose by organ. As a result, first, 24 hours after administering, the average thyroidal uptake and the daily urination ratio registered 19.70% and 71.12%, respectively. Second, the whole body effective dose according to the thyroidal uptake calculated herein and the existing ICRP-suggested thyroidal uptake of 30% offered 1.464E-08 Sv and 2.189E-08 Sv, respectively, showing a 1.5 times difference. To evaluate the quantity of the absorbed dose of radioactive iodine, we can better reduce the error in assessing the body exposure dose by conducting measurement according to human races rather than depending on the existing ICRP data.

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