• Title/Summary/Keyword: Y123

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Evaluation of Sympathetic Innervation in Cardiomyopathy with $^{123}I-MIBG$ (심근병에서 $^{123}I-MIBG$ 영상을 이용한 교감신경기능의 평가)

  • Kim, Sun-Jung;Lee, Jong-Doo;Lee, Do-Yun;Park, Chang-Yoon;Ham, Jin-Kyung;Chung, Nam-Sik;Cho, Seung-Yun;Lee, Sung-Sook;Kim, Young-Soo
    • The Korean Journal of Nuclear Medicine
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    • v.27 no.2
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    • pp.195-202
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    • 1993
  • $^{123}Iodine$-metaiodobenzylguanidine (MIBG) which is a norepinephrine analogue, can be used to evaluate the sympathetic innervation of the heart. In this study, cardiac imaging with $^{123}I-MIBG$ was performed in patients with 9 dilated cardiomyopathy, 2 ischemic cardiomyopathy and 1 acute myocardial infarction to evaluate the sympathetic nervous function. $^{123}I-MIBG$ imaging showed multifocal defects (8), diffuse defect (2), near non-visualization (2). The defects of MIBG scans were found to be larger and more severe on 4 hours image than 30 minutes. Heart to lung, heart to mediastinum ratios were decreased at 4 hours than those at 30 minutes. Measured LVEF values were not correlated with the severity of MIBG uptake. $^{99m}Tc-MIBI$ imaging was also performed in all patients to find the relationship with $^{123}I-MIBG$ scan. $^{99m}Tc-MIBI$ scan showed multifocal defects in 9 patients, diffuse defects in 1 patient and no defect in 2 patients. The defects are similar in size, severity and extent, but more larger and severe on $^{123}I-MIBG$ imaging. Therefore, cardiac $^{123}I-MIBG$ imaging is a useful method to evaluate the sympathetic nervous function in cardiomyopathy.

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The Effects of Dead Time and Its Correction Methods for Thyroid Prode using $^{99m}Tc$, $^{123}I$, $^{131}I$ ($^{99m}Tc$, $^{123}I$, $^{131}I$을 이용한 갑상선 탐침의 계수 불능시간영향의 특성과 그의 보정 방법에 관한 연구)

  • 손혜경;김희중;나상균;이희경
    • Progress in Medical Physics
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    • v.7 no.1
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    • pp.79-89
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    • 1996
  • The purpose of this study was to examine the dead time effects and derive the correction factor. Using the thyroid probe and lucite cylindrical phantom, $^{99m}Tc$ 10.50mCi and $^{123}I$ 2.08mCi were counted with medical spectrometer at intervals of 2 hours for 43hrs and 79 hours. respectively. $^{123}I$ 2.06mCi was counted at intervals of 6 hours for 910 hours. To measure the starting point of dead time effect, the radioactivity was measured with dose calibrator in each time. The dead time effects started at about 0.80mCi at all distances for $^{99m}Tc$, and about 1.00mCi for $^{123}I$. The radioactivity corresponding to 20% counts loss is 1.29(center), 1.28(2cm), 1.31(4cm), 1.13(6cm)mCi for $^{99m}Tc$ and 1.39mCi for $^{123}I$. The correction factors for 2mCi of radioactivity as an example were 1.52(center), 1.52(2cm), 1.50(4cm), 1.58(6cm) for $^{99m}Tc$ and 1.58 for $^{123}I$.

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Effect of Liposome Encapsulation on Intestinal Absorption of Rhodamine 123 (리포솜 봉입이 로다민 123의 소장 흡수에 미치는 영향)

  • Hong, Soon-Sun;Lee, Hae-Ree;Li, Hong;Chung, Suk-Jae;Kim, Dae-Duk;Shim, Chang-Koo
    • YAKHAK HOEJI
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    • v.49 no.2
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    • pp.185-191
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    • 2005
  • The absorption of a P-gp substrate, rhodamine 123, from a liposomal dosage form was investigated across Caco-2 cell monolayers, rat intestines and rat intestinal Peyer's patches in Ussing chamber, Rhodamine 123 was incorporated into liposomes according to the standard evaporation method, which led to a production of liposomes with a mean diameter of 71.3 nm. The permeability (Papp of rhodamine 123 from a water solution across the monolayer was $2.45{\times}10^{-6}$ cm/s for $A{\leftrightarrow}B$ (apical to basal) and $14.0{\times}10^{-6}$ cm/s for $B{\leftrightarrow}A$ (basal to apical) directions, consistent with the fact that rhodamine 123 is one of the P-gp substrates. The transport of rhodamine 123 from the liposomal dosage form was much lower for both directions compared to the solution of rhodamine 123. The transport of rhodamine 123 across the rat intestine was also significantly decreased for both directions, I.e., influx and efflux, by the liposomal incorporation of the compound. The transport of rhodamine 123 across the Peyer's patch was substantially reduced by liposomal incorporation. No difference was found in the transport between the Peyer's patch and non-Peyer's patch. These observations suggest that the contribution of transport via Peyer's patches in the uptake of liposomes may be minimal, especially for rapidly absorbed compounds like rhodamine 123. Therefore, the increased absorption of P-gp substrates does not appear to be feasible by incorporating the compounds in liposomes, due to negligible involvement of Peyer's patches in the uptake of particulate dosage forms like liposomes. Liposomes may rather represent a sustained release dosage form of incorporated compounds.

Flux Pinning Enhancement in $(Y_{0.5}Nd_{0.25}Sm_{0.25})Ba_{2}Cu_{3}O_y$ Oxides by Zone Melt Growth Process

  • Kim So-Jung
    • KIEE International Transactions on Electrophysics and Applications
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    • v.5C no.6
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    • pp.251-256
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    • 2005
  • Directionally melt-textured high $T_c\;(Y_{0.5}Nd_{0.25}Sm_{0.25})Ba_{2}Cu_{3}O_y$ [(YNS)-123] superconductor was systematically investigated by the zone melt growth process in air. A sample prepared by this method showed well-textured microstructure, and $(Y_{0.5}Nd_{0.25}Sm_{0.25})_{2}BaCuO_5$[(YNS)211] inclusions were uniformly dispersed in large $(Y_{0.5}Nd_{0.25}Sm_{0.25})Ba_{2}Cu_{3}O_y$ [(YNS)123] matrix. High irreversibility field and magnetization hysteresis loop of the zone melt-textured (YNS)-123 sample exhibited the enhanced flux pinning, compared with $YBa_{2}Cu_{3}O_y$ (Y-123) sample without RE(rare earth). Critical current density of (YNS)-123 sample was $2.5{\times}10^4\;A/cm^2$ at 2 T and 77 K.

Magnetic Properties of $GdBa_2Cu_3O_{7-y}$ Bulk Superconductors Fabricated by a Top-seeded Melt Growth Process (종자 결정 성장법으로 제조된 $GdBa_2Cu_3O_{7-y}$ 벌크 초전도체의 자기적 특성)

  • Kim, K.M.;Park, S.D.;Jun, B.H.;Ko, T.K.;Kim, C.J.
    • Progress in Superconductivity
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    • v.14 no.1
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    • pp.39-44
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    • 2012
  • The fabrications condition and superconducting properties of top-seeded melt growth (TSMG) processed $GdBa_2Cu_3O_{7-y}$ (Gd123) bulk superconductors were studied. Processing parameters (a maximum temperature ($T_{max}$), a temperature for crystal growth ($T_G$) and a cooling rate ($R_G$) through a peritectic temperature ($T_P$) for the fabrication of single grain Gd123 superconductors were optimized. The magnetic levitation forces, trapped magnetic fields, superconducting transition temperature ($T_c$) and critical current density ($J_c$) of the Gd123 bulks superconductors were estimated. Single grain Gd123 bulk superconductors were successfully fabricated at the optimized processing condition. The $T_c$ of a TSMG processed Gd123 sample was 92.5 K and the $J_c$ at 77 K and 0 T was approximately $50kA/cm^2$. The trapped magnetic field contour and magnetic levitation forces were dependent on the top surface morphology of TSMG processed Gd123 samples. The single grain Gd123 samples, field-cooled at 77 K using a Nd-B-Fe permanent magnet with 5.27 kG and 30 mm dia., showed the trapped magnetic field contour of a single grain with a maximum of 4 kG at the sample center. The maximum magnetic levitation forces of the single grain Gd123 sample, field-cooled or zero field-cooled, were 40 N and 107 N, respectively.