• 대한방사성의약품학회지
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• 제3권2호
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• pp.98-102
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• 2017

We demonstrate a detail protocol for the radiosynthesis of a $^{125}I-labeled$ tetrazine prosthetic group and its application to the efficient radiolabeling of trans-cyclooctene-group conjugated human serum albumin (3) using inverse-electron-demand Diels-Alder reaction. Radioiodination of the stannylated precursor (2) was carried out by using [$^{125}I$]NaI and chloramine T as an oxidant at room temperature for 15 min. After HPLC purification of the crude product, the purified $^{125}I-labeled$ azide ([$^{125}I$]1) was obtained with high radiochemical yield ($65{\pm}8%$, n = 5) and excellent radiochemical purity (>99%). Inverse-electron-demand Diels-Alder reaction between ([$^{125}I$]1) and 3 gave the $^{125}I-labeled$ human serum albumin ([$^{125}I$]4) with more than 99% of radiochemical yield as determined by radio-thin-layer chromatography (radio-TLC). These results clearly indicate that the present radiolabeling method will be useful for the efficient and convenient radiolabeling of trans-cyclooctene-group containing biomolecules.

• 대한방사성의약품학회지
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• 제4권2호
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• pp.85-89
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• 2018

We demonstrate a detail protocol for the radiosynthesis of an $^{125}I$-labeled MSTP prosthetic group and its application to the efficient radiolabeling of human serum albumin (HSA). Radioiodination of the precursor (2) was carried out by using $[^{125}I]$NaI and chloramine T as an oxidant at room temperature for 15 min. After HPLC purification of the crude product, the purified $^{125}I$-labeled MSTP ($[^{125}I]1$) was obtained with high radiochemical yield ($73{\pm}5%$, n = 3) and excellent radiochemical purity (>99%). Site-specific reaction between ($[^{125}I]1$) and HSA gave the $^{125}I$-labeled human serum albumin ($[^{125}I]3$) with more than 99% of radiochemical yield as determined by radio-thin-layer chromatography (radio-TLC). These results clearly demonstrate that the present radiolabeling method will be useful for the efficient and convenient radiolabeling of thiol-bearing biomolecules.

• Nuclear Engineering and Technology
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• 제45권1호
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• pp.61-66
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• 2013

Among the radioactive wastes generated from the nuclear power plant, a radioactive nuclide such as $^{129}I$ is classified as a difficult-to-measure (DTM) nuclide, owing to its low specific activity. Therefore, the establishment of an analytical procedure, including a chemical separation for $^{129}I$ as a representative DTM, becomes essential. In this report, the adsorption and recovery rate were measured by adding $^{125}I$ as a radio-isotopic tracer ($t_{1/2}$ = 60.14 d) to the simulation sample, in order to measure the activity concentration of $^{129}I$ in a pressurized-water reactor primary coolant. The optimum condition for the maximum recovery yield of iodine on the anion exchange resins (AG1 x2, 50-100 mesh, $Cl^-$ form) was found to be at pH 7. In this report, the effect of the boron content in a pressurized-water reactor primary coolant on the separation process of $^{129}I$ was examined, as was the effect of $^3H$ on the measurement of the activity of iodine. As a result, no influence of the boron content and of the simultaneous $^3H$ presence was found with activity concentrations of $^3H$ lower than 50 Bq/mL, and with a boron concentration of less than 2,000 ${\mu}g/mL$.

• Nuclear Engineering and Technology
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• 제56권7호
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• pp.2732-2739
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• 2024

This study developed internal dose coefficients for radioiodine, tailored to the Korean population, by incorporating the Korean biokinetic model along with the Korean S values. The observed differences in dose coefficients for Koreans compared to the International Commission on Radiological Protection (ICRP) reference values noticeably varied depending on physical half-lives of iodine isotopes. For longer-lived isotopes such as I-125 and I-129, significant differences in thyroid dose coefficients were observed, with ratios (Korean/ICRP) from 0.30 to 0.55, indicating that actual doses for Koreans can be considerably lower than those evaluated based on the ICRP data. However, for short-lived iodine isotopes, such as I-131, the thyroid dose coefficients were comparable to the ICRP reference values (ratio = 0.95-0.98). These comparable dose coefficients resulted from the lower thyroidal iodine uptake in the Korean model being almost entirely offset by the higher thyroid self-absorption S values in the Korean phantoms. Additionally, this study delves into the substantial differences in absorbed dose coefficients for non-thyroidal regions and effective dose coefficients, which arose not only from physiological/anatomical variability but also technical differences in phantom design. The use of Korean-specific dose coefficients is advisable particularly in scenarios predicting elevated doses, yielding a more precise and clinically relevant dose assessment.

• Nuclear Engineering and Technology
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• 제51권1호
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• pp.125-137
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• 2019

The purpose of this paper is to study the source term behavior after severe accidents by using a semi-kinetic model for simulation and calculation of in-containment activity. The reactor containment specification and the safety features of the containment under different accident conditions play a great role in evaluating the in-containment activity. Assuming in-vessel and instantaneous release of radioactivity into the containment, the behavior of in-containment isotopic activity is studied for noble gasses (Kr and Xe) and the more volatile elements of iodine, cesium, and aerosols such as Te, Rb and Sr as illustrative examples of source term release under LOCA conditions. The results of the activity removal mechanisms indicates that the impact of volumetric leakage rate for noble gasses is important during the accident, while the influence of deposition on the containment surfaces for cesium, mainly iodine isotopes and aerosol has the largest contribution in removal of activity during evolution of the accident.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.4003-4006
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• 2015

Objecive: To investigate the clinical safety and efficacy of CT-guided $^{125}iodine$ (125I) seed implantation combined with percutaneous intra-tumor injection of chemotherapy emulsion of lobaplatin and lipiodol in treating patients with advanced lung cancer. Materials and Methods: Patients with advanced lung cancer and treated with spiral CT-guided $^{125}I$ seed implantation combined with percutaneous intra-tumor injection of chemotherapy emulsion of lobaplatin and lipiodol were recruited. Results: Of the 36 patients, there were 40 nidi in total. The contrast-enhanced CT evaluation was conducted 60 d after treatment. Response evaluation suggested that 4 patients achieved complete remission (CR), 24 partial remission (PR), 4 stable disease (SD) and 4 progression disease (PD), with a total response rate of 77.8% (28/36). Conclusions: CT-guided $^{125}I$ seed implantation combined with percutaneous intra-tumor injection of chemotherapy emulsion of lobaplatin and lipiodol are safe and effective in treating patients with advanced lung cancer.

• 방사선산업학회지
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• 제5권3호
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• pp.197-202
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• 2011

In this study, an Ag-polyaniline-silica (Ag-PANI-silica) nanoparticle was evaluated as a radioisotope carrier. An Ag-PANI-silica nanoparticle was incubated in the $^{125}I$ solution for a duration of 24 hr to test its radioisotope absorptivity. During the incubation, radioactivity of the nanoparticle was measured at 3, 6, 12, and 24 hr. After a 24 hr incubation, $^{125}I$-Ag-PANI-silica nanoparticle was incubated in a fresh saline for a duration of 48 hr to check its stability. Additionally, the $^{125}I$-Ag-PANI-silica nanoparticle was injected to the ICR mouse to investigate its in-vivo distribution characteristics. The $^{125}I$ absorption yield of the Ag-PANI-silica nanoparticle was higher than 95% after a 6 hr incubation period in the $^{125}I$ solution. And $^{125}I$-Ag-PANI-silica was stable for 48 hr at 80% yield at room temperature. The SPECT/CT image of a mouse that received $^{125}I$-Ag-PANI-silica complex showed that the $^{125}I$-Ag-PANI-silica complex was distributed in the lung, stomach and thyroid at 30 min post injection. From these results, the Ag-PANI-silica nanoparticle has good radio-iodine carrying property and can be applicable for the purpose of diagnosis and therapy.

• 대한핵의학회지
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• 제38권1호
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• pp.74-84
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• 2004

목적:. I-125는 저에너지(27-35 keV) 방사선을 방출하기 때문에 두께가 얇은 섬광결정과 조준기를 사용할 수 있어 고분해능, 고민감도 영상획득에 유리한 물리적 특성을 가지고 있다. 이 연구의 목적은 새로운 시뮬레이션 도구인 GATE (Geant4 Application for Tomographic Emission)를 사용하여 최적의 I-125 SPECT 시스템 파라미터를 도출하는 것이다. 대상 및 방법: 시뮬레이션 방법의 신뢰성을 검증하기 위해, Weisenberger 등이 개발한 감마 카메라 시스템을 모사하였다. 섬광체로 평판형 Nal(T1)을 사용하였으며, 두께는 검출효율을 계산해서 결정하였다. 평행구멍조준기와 바늘구멍조준기의 여러 파라미터가 공간분해능과 민감도에 미치는 영향을 평가하였다. 그리고 최적화된 조준기를 결합한 I-125 SPECT의 성능을 평가하였다. 결과: 시뮬레이션에 대한 신뢰성 검증연구 결과, 측정과 시뮬레이션에서 공간분해능(4%)과 민감도(3%)가 유사함을 확인하였다. Nal(T1) 두께는 I-125 감마선을 98% 검출할 수 있도록 1 mm로 결정하였다. 시뮬레이션 결과 고분해능 평행구멍조준기로 구멍크기가 0.2 mm이고 길이가 5 mm인 사각구멍조준기를 선택하였고, 범용 평행구멍조준기로 구멍크기가 0.5 m이고, 길이가 10 mm인 육각구멍조준기를 선택하였다. 바늘구멍조준기는 구멍지름이 0.25 mm이고 채널높이가 0.1 mm이며, 허용각도가 90도인 조준기를 선택하였다. 최적화된 고분해능 평행구멍조준기, 범용 평행구멍조준기, 바늘구멍조준기를 결합한 I-125 SPECT의 재구성 영상 공간분해능은 각각 1.2 mm, 1.7 mm, 0.8 mm였으며, 민감도는 39.7 cps/MBq, 71.9 cps/MBq, 5.5 cps/MBq이었다. 결론: GATE 시뮬레이션으로 I-125 영상에 적합한 섬광결정 파라미터 및 조준기 파라미터를 도출하였다. 이 연구결과는 I-125 SPECT로 탁월한 고분해능, 고민감도 영상을 얻을 수 있음을 보여준다.

• Nuclear Engineering and Technology
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• 제10권1호
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• pp.1-12
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• 1978

Concanavalin-A, 한국산 반하(半夏)로부터 주출된 Lectin 및 이들과 tyrosine 또는 5-iodo-6-aminouracil을 결합시킨 화합물들을 각각 방사성 요오드-125로 표지 하였으며 표지된 화합물들을 사용하여 생체외부 시험법으로 혈액응고 시험을 실시하였다. 표지반응에 관하여 표지수율과 함께 그 실험조건을 보고하였으며 Lectin과 여러 아미노산계통 화합물들과의 결합반응성을 논의하였다. 암세포에 대한 혈액응고 시험결과를 보고하였으며 이들 표지화합물들의 임상적 실용전망에 관하여서도 논의하였다.

• 약학회지
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• 제41권3호
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• pp.381-388
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• 1997

Metabolism of DWP401, recombinant juman epidermal growth factor, was examined in vivo and in vitro in rats. When $^{125}I$-labeled DWP401 was administered at a dose of 50 ${\mu}g$/kg by i.v. injection. $^{125}I$-labeled DWP401 was rapidly degraded within 30 minytes above 93%. Thin layer chromatography analysis of urine collected for 24 hr after i.v. administration of $^{125}I$-labeled DWP401 showed ohly one spot on a X-ray film which was considered as diiodo-tyrosine. This result suggests tha $^{125}I$-labeled DWP401 was completely digested into free amino acids without any specific intermediate polypeptides. About 42.1% of the administered iodine was recovered in 24 hr. For in vitro degradation study, $^{125}I$-labeled DWP401 was added to plama and tissue homogenates of rats and incubated at $37^{\circ}C$. Almost 98% of the added radioactivity recovered from the protein fraction of the liver, kidey, small intestine, stomach and spleen decreased rapidly. For examplem the recovery rates of $^{125}I$-labeled DWP401 were 58.6, 63.2, 39.9, 52.9 and 66.8% after 4hrs of incubation in respective organ homogenates.