• 대한방사선기술학회지:방사선기술과학
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• 제44권2호
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• pp.109-115
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• 2021

In this study, a physical evaluation of internal radiation exposure in children was conducted using nuclear medicine test(Renal DTPA Dynamic Study) to simulate the distribution and effects of the radiation throughout the tracer kinetics over time. Monte Carlo simulations were performed to determine the internal medical radiation exposure during the tests and to provide basic data for medical radiation exposure management. Specifically, dose variability based on changes in the tracer kinetic was simulated over time. The internal exposure to the target organ (kidney) and other surrounding organs was then quantitatively evaluated and presented. When kidney function was normal, the dose to the target organ(kidney) was approximately 0.433 mGy/mCi, and the dose to the surrounding organs was approximately 0.138-0.266 mGy/mCi. When kidney function was abnormal, the dose to the surrounding organs was 0.228-0.419 mGy/mCi. This study achieved detailed radiation dose measurements in highly sensitive pediatric patients and enabled the prediction of radiation doses according to kidney function values. The proposed method can provide useful insights for medical radiation exposure management, which is particularly important and necessary for pediatric patients.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2419-2431
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• 2023

Experiments related to Boron Neutron Capture Therapy (BNCT) accomplished at the Institute of Nuclear Techniques (INT), Budapest University of Technology and Economics (TUB) are presented. Relevant investigations are required before designing BNCT for vivo applications. Samples of relevant boron compounds (H₃BO₃, BDTPA) usually employed in BNCT were investigated with neutron beam. Channel #5 in the research reactor (100 kW) of INT-TUB provides the neutron beam. Boron samples are mounted on a carrier for neutron irradiation. The particle attenuation of several carrier materials was investigated, and the one with the lowest attenuation was selected. The effects of boron compound type, mass, and compound phase state were also investigated. To detect the emitted charged particles, a traditional ZnS(Ag) detector was employed. The neutron beam's interaction with the detector-detecting layer is investigated. Graphite (as a moderator) was employed to change the neutron beam's characteristics. The fast neutron beam was also thermalized by placing a portable fast neutron source in a paraffin container and irradiating the H₃BO₃. The obtained results suggest that the direct measurement approach appears to be insufficiently sensitive for determining the radiation dose committed by the Alpha particles from the ¹⁰B (n,α) reaction. As a result, a new approach must be used.

• 대한핵의학회지
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• 제34권5호
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• pp.418-425
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• 2000

목적: 감마카메라를 이용한 사구체 여과율 측정에 필요한 신장 깊이에 관한 자료는 대부분 Tonnesen 등이 서양인의 신장 깊이를 토대로 작성한 방정식을 채용하고 있는데 이 방법은 신장 깊이를 과소 평가하는 것으로 알려져 있다. 이에 저자들은 서양인과 체격 조건이 다른 한국인의 신장 깊이에 관한 방정식을 도출하여 다른 방법과 비교하고 이를 사구체 여과율 측정에 이용하고자 하였다. 대상 및 방법: 신장에 이상 소견이 없는 성인 300명(남:여=167:133, 평균나이, 50.9세)의 복부 CT 사진 중 신문이 나온 영상에서 피부면으로부터 신장의 최전면과 최후면까지의 깊이를 각각 측정하여 평균 깊이를 구하였다. 대상이 된 300명중 200명을 무작위 추출하여 성별, 나이, 체중, 키를 변수로 하여 방정식을 도출하였고, 이를 토대로 산출한 신장 길이와 대조군 100명의 신장 길이 측정치를 비교하였다. 이어 Tc-99m DTPA 신장 신티그람을 시행한 또 다른 48명(남:여=25:23, 평균나이: 50.6세)에서 Tonnesen, Taylor와 저자들의 방정식으로 각각 산출한 신장 깊이를 사용하여 Gates 방법으로 사구체 여과율을 측정하여 비교 분석하였다. 결과: CT로 측정한 신장 깊이의 평균은 남자 우신; 6.9 좌신; 6.7, 여자 우신: 6.7 좌신: 6.6 cm이었다. 저자들의 측정치와 비교할 때 Tonnesen 방정식으로 구한 산출기(남자 우신: 5.5 좌신: 5.5, 여자 우신: 5.4 좌신: 5.4 cm)는 낮았고 그 차이는 통계적으로 유의하였다. Taylor 방정식의 산출치(남자 우신: 6.8 좌신: 6.4, 여자 우신: 6.6 좌신: 6.1 cm)는 여자 좌신을 제외하고는 모두 비슷하였다. 저자들이 도출한 방정식은 남자 우신: 12.813(체중/키)+0.002(나이)+2.264, 좌신: 15.344(체중/키) +0.011(나이) +0.557, 여자 우신: 12.936(체중/키)+0.014(나이)+1.462 좌신: 13.488(체중/키)+0.019(나이)+0.762 이었다. 이 방정식의 산출치를 대조군의 측정치와 비교한 결과 남자 우신과 좌신, 여자 우신과 좌신에서의 상관계수 r은 각각 0.529, 0.729, 0.601, 0.724 이었다. 3가지 방정식을 이용하여 측정한 사구체 여과율 중 저자들의 방정식으로 구한 것이 가장 큰 값을 보여 정상 사구체 여과율에 가장 가까웠고 Tonnesen 방정식으로 구한 것이 가장 낮았다. 결론: 한국인 신장 깊이를 토대로 만든 방정식을 이용하여 한국인의 사구체 여과율을 비롯한 신장 청소율과 Tc-99m DMSA 신장 섭취율 등을 보다 정확하게 측정할 수 있을 것으로 기대된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권5호
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• pp.23-31
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• 2010

For an efficient remediation of Pb-contaminated soil (S-1) in a clay shooting range, a soil washing test was performed with mineral acid, organic acid, chelating agent, and chloride. The Pb extraction efficiency of extractant (0.1 M) used in the washing test showed the order of HCl > $Na_2$-EDTA > NTA > DTPA > citric acid > malic acid > succinic acid > acetic acid > $CaCl_2$ > $MgCl_2$, for S-1 soil. As compared to initial Pb concentration, extraction efficiency by the concentration of extractant was 93.35%, 80.80%, 73.92%, and 24.57% in S-1 soil for HCl (0.5 M, pH 1.10), $Na_2$-EDTA (0.01 M, pH 3.99), citric acid (0.5 M, pH 1.27), and $MgCl_2$ (0.1 M, pH 8.82), respectively. S-1 soil had 56.83% of residue form and 43.17% of non-residue form (18.04% of exchangeable form), respectively. Although the concentrations of these fractions sharply decreased after HCl washing, since the exchangeable forms with relatively large mobility are still distributed as high as 18.78% (to Pb total content in residual soils) in S-1 soil, it is necessary to devise a proper management plan for residual soils after soil washing application.

• 대한핵의학회지
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• 제16권2호
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• pp.81-84
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• 1982

To evaluate the in-vivo and in-vitro stability of methylene diphosphonate $(MDP)-^{99m}Tc$, relative ligand exchange rates in phosphate buffer between $MDP-^{99m}Tc$ and human serum albumin (HSA), and between pyrophosphate$(PYP)-^{99m}Tc$ and HSA have been measured. Gel permeation chromatography has also been carried out to estimate relative rates of ligand exchange between polysaccharide and the $^{99m}Tc-bone$ agents. The in-vitro stability was further correlated with its specific radioactivity. The results indicated that the $MDP-^{99m}Tc$ is more stable than the $PYP-^{99m}Tc$ but less stable than $MIDA-^{99m}Tc$, $HIDA-^{99m}Tc$, and $DTPA-^{99m}Tc$ etc. in refering to other data. In stability point of view, $MDP-^{99m}Tc$ is considered to be a better bone agent than $PYP-^{99m}Tc$ since $MDP-^{99m}Tc$ can be accumulated at bone by a smooth transfer of $^{99m}Tc$ to hydroxyapatite, whereas in case of $PYP-^{99m}Tc$, most of the $^{99m}Tc$ is transferred to HSA before arriving to the hydroxyapatite.

• 대한핵의학회지
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• 제20권2호
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• pp.73-78
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• 1986

Of 18 patients with Takayasu's arteritis who underwent $^{99m}Tc-MAA$ (macroaggregated albumin) perfusion luing scanning, 9 (50%) showed perfusion defects. Chest X-rays of them were nonspecific. One patient underwent $^{99m}Tc-DTPA$ radio aerosol inhalation lung scanning simultaneously, which revealed normal. So routine screening radioisotope perfusion lung scanning is helpful to evaluate pulmonary arterial involnmement in Takayasu's arteritis patients. And Takayasu's arteritis should be included in differential diagnosis of pulmonary embolism.

• The Korean Journal of Physiology and Pharmacology
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• 제3권6호
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• pp.631-640
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• 1999

The present study investigated the stimulatory effects of iron (or ascorbate) on cyclosporine-induced kidney mitochondrial damage. Damaging effect of $50\;{\mu}M$ cyclosporine plus $20\;{\mu}M\;Fe^{2+}$ on mitochondrial lipids and proteins of rat kidney and hyaluronic acid was greater than the summation of oxidizing action of each compound alone, except sulfhydryl oxidation. Cyclosporine and $100\;{\mu}M$ ascorbate showed an enhanced damaging effect on lipids but not on proteins. The peroxidative action of cyclosporine on lipids was enhanced with increasing concentrations of $Fe^{2+}.$ Ferric ion $(20\;{\mu}M)$ also interacted with cyclosporine to stimulate lipid peroxidation. Damaging action of cyclosporine on mitochondrial lipids was enhanced by ascorbate $(100\;{\mu}M\;and\;1\;mM)$. Iron chelators, DTPA and EDTA, attenuated carbonyl formation induced by cyclosporine plus ascorbate. Cyclosporine $(100\;{\mu}M)$ and $50\;{\mu}M\;Fe^{2+}$ $(or\;100\;{\mu}M\;ascorbate)$ synergistically stimulated degradation of $2-{\alpha}$ deoxyribose. Cyclosporine $(1\;to\;100\;{\mu}M)$ reduced ferric ion in a dose dependent manner, which is much less than ascorbate action. Addition of $Fe^{2+}$ caused a change in absorbance spectrum of cyclosporine in $230{\sim}350$ nm of wavelengths. The results show that cyclosporine plus iron (or ascorbate) exerts an enhanced damaging effect on kidney mitochondria. Iron and ascorbate appear to promote the nephrotoxicity induced by cyclosporine.

• 대한핵의학회지
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• 제24권2호
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• pp.325-331
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• 1990

Radionuclide renal scintigraphies were performed in a 24-year-old man with right renal artery branch stenosis. Captopril enhanced $^{99m}Tc-DTPA$ renal scintigraphy revealed no abnormal finding in the right kidney. But, $^{99m}Tc-DMSA$ renal scintigraphy showed regional cortical photon deficient area corresponding to the area supplied by the stenotic branch artery. The defect size increased in captopril enhanced $^{99m}Tc-DMSA$ renal scintigrphy and nearly disappeared after successful transluminal renal angioplasty. This case suggests that the captopril enhanced $^{99m}Tc-DMSA$ renal scintigraphy may be a useful method in the evaluation of renovascular hypertension, especially due to branch renal srtery stenosis.

• 대한핵의학회지
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• 제28권1호
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• pp.106-111
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• 1994

2-iminothiolane is known to bind $NH_2$ group of lysine in the protein and deliver SH group, which can be used to label protein with $^{99m}Tc$. In this study, we looked for the best reaction condition in which 2-iminothiolane is conjugated to human polyclonal IgG and labeling condition with $^{99m}Tc$-glucoheptonate. Labeling yield was measured with TSK G4000SW column and HPLC or precipitation with 10% TCA (trichloroacetic acid) and 1% HSA. In vivo distribution was investigated with Staphylococcal abscess bearing rats. With decreasing glucoheptonate, the labeling yield decreased. Without 2-iminothiolane, $^{99m}Tc$-glucoheptonate was bound to IgG, which seemed to be direct labeling. With increasing 2-iminothiolane upto 20 times higher than IgG, the labeling yield increased, and plateau was seen with higher molar excess of 2-iminothiolane. Polymer formation was not observed. The pH for the conjugation of 2-iminothiolane and IgG was best around 6.4. $^{99m}Tc$-2-iminothiolane-IgG showed faster blood clearance, higher renal activity and lower hepatic and splenic activity than $^{99m}Tc$-DTPA-IgG. The biodistribution of $^{99m}Tc$-2-iminothiolane-IgG with higher molar excess of 2-iminothiolane was not different from that with lower molar excess. Labeling antibodies with $^{99m}Tc$ using 2-iminothiolane can afford a possible route to simple labeling and wide clinical use of the immunoscintigraphy.

• 한국환경농학회지
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• 제25권2호
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• pp.157-163
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• 2006

Investigation of Cd and Zn availability in four different soils as affected by the interactions of these two heavy metals was conducted using the metal desorption quantity-intensity (Q/I) isotherms. The soils were artificially contaminated with proper concentrations of Cd and Zn as $CdSO_4\;and\;ZnSO_4$ solutions. DTPA (diethylene triamine pentaacetic acid) - extractable and water-extiactable Cd or Zn from the soils were used as $Q_{Cd}\;or\;Q_{Zn}\;and\;I_{Cd}\;or\;I_{Zn}$ factors, respectively. The coefficient of determination for Cd and Zn desorption Q/I linear regression in the soils ranged from 0.947 to 0.999, which indicated that Q and I factors were closely correlated. The buffering capacity of Cd, $BC_{Cd}$, in the soils decreased with increasing Zn treatments, and the $BC_{Cd}$ values were ranged between 205.8 and 2255.6. The decreases of $BC_{Cd}$ values were mainly dependent upon the increases of $I_{Cd}$ factors. However, Zn buffering capacity. $BC_{Zn}$ decreased with increasing Cd treatments in acidic soils, and increased in neutral and calcareous alkaline soils. The $BC_{Cd}$ values were ranged from 143.2 to 6158.0. The values of $BC_{Zn}$ as influenced by the treatments of Cd were also controlled by the solubility of water-extractable Zn, $I_{Zn}$ factor. The solubility of water-extractable Cd and Zn was significantly dependent upon the changes of soil pH that were impacted by the treatment of Zn and Cd, respectively. Also, the availability of Cd was higher than Zn availability in the acidic and neutral soils, but Zn was higher than Cd in the calcareous alkaline soil.