• Nuclear Medicine and Molecular Imaging
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• v.41 no.6
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• pp.546-552
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• 2007

Purpose: In the breast cancer patient, lymphatic mapping and sentinel lymph node biopsy are the most important procedure for axillary lymph node staging. We aimed to compare the three radiocolloids [$^{99m}Tc$-antimony trisulfide colloid (ASC), $^{99m}Tc$-tin colloid (TC), and $^{99m}Tc$-human serum albumin (HSA)] for sentinel lymph node mapping. Subjects and Methods: Totally, 397 patients with clinically N0 stage were enrolled. $^{99m}Tc$-ASC was injected in 202 out of 397 patients, $^{99m}Tc$-TC was injected in 120 patients, and $^{99m}Tc$-HSA was injected in the remaining 75 patients. The sentinel lymph nodes were localized by lymphoscintigraphy and selected using intraoperative gamma probe. All sentinel lymph nodes were investigated by intraoperative pathologic consultation. The axillary lymph nodes which were harvested by the lymph node dissection were also investigated. Results: The patients of each group showed similar clinical characteristics. There were no significant differences (p>0.05) in the identification rate of sentinel lymph nodes (IR), false negative rate (FNR), and negative predictive value (NPV). The axillary lymphadenectomy revealed axillary lymph node metastases in those three groups (ASC-33.2%, TC-31.7%, HSA-22.7%). The IR, FNR, and NPV were not significantly different among those groups. Conclusion: Those three $^{99m}Tc$-labeled radiocolloids showed equivalent results in sentinel lymph node mapping of breast cancer.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1B
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• pp.153-160
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• 2008

To estimate microbial contaminant loading discharged from diffuse sources, rainfall runoff of six rainfall events were monitored at three study watersheds of forestry and agricultural land use. Monitored indicator microorganism constituents were total coliform (TC), fecal coliform (FC), Escherichia coli (EC), and fecal streptococcus (FS). Soil loss during elevated flow rate caused higher suspended solid concentrations. Indicator microorganism concentrations were closely related with flow rate. TC event mean concentration (EMC) from unpolluted forestry was $5.3{\times}10^3CFU/100ml$, FC EMC was $1.4{\times}10^3CFU/100ml$, EC EMC was $1.1{\times}10^3CFU/100ml$, and FS EMC was $2.9{\times}10^2CFU/100ml$. From a watershed with agricultural-forestry land use, TC EMC was $1.7{\times}10^5CFU/100ml$, FC EMC was $8.5{\times}10^4CFU/100ml$, EC EMC was $8.9{\times}10^4CFU/100ml$, and FS EMC was $3.4{\times}10^4CFU/100ml$. Mixed land use of agricultural-forestry with bigger area, TC EMC was $1.9{\times}10^5CFU/100ml$, FC EMC was $9.6{\times}10^4CFU/100ml$, EC EMC was $7.0{\times}10^4CFU/100ml$, and FS EMC was $5.1{\times}10^4CFU/100ml$.

• The Korean Journal of Nuclear Medicine Technology
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• v.28 no.1
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• pp.1-11
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• 2024

Hypoxia, defined as the deficiency of oxygen, is a significant hallmark of cancers presenting in the majority of solid tumors. Detection of tumor hypoxia is essential in cancer diagnosis to prevent cancer progression, metastasis, and resistance to cancer therapies in clinical practices. Single-photon emission computed tomography (SPECT) is one of the methods studied and applied for hypoxia detection with the use of radiolabeled imaging agents in which ^99mTc is the common radioisotope used for radiolabeling. Nitroimidazoles are the hypoxia-targeting moieties presenting in numerous ^99mTc-radiolabeled imaging agents due to their bio-reducible ability in hypoxic environments. Recently, in addition to ^99mTc-labeled radiopharmaceuticals containing one nitroimidazole unit, there has been considerable attention given to ^99mTc-radiopharmaceuticals bearing two or more nitroimidazole units. This review summarizes the synthesis of hypoxia-targeting chelators and radiolabeling processes to produce these ^99mTc-radiopharmaceuticals for SPECT imaging.

• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.69-74
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• 1994

Authors retrospectively analysed 20 cases of follow-up $^{99m}Tc$-DMSA renal scans to evaluate renal function recovery after treatment in urologic disorders of infants and children. There were 20 cases with both $^{99m}Tc$-DMSA renal scans prior to and after therapy in 15 patients below 9 years old. Among them, 10 patients underwent ureteroneocystostomy under the diagnosis of vesicoureteral reflux, two patients pyeloplasty because of obstructive uropathy and one was treated with antibiotics even diagnosis of UPJ stricture. We have got the quantified uptake rate of $^{99m}Tc$-DMSA renal scan by using the regression equation as "y=0.591x-2.105" (y=the quantified uptake rate, x=the simple uptake rate). The number of kidneys performed proper therapy were 29, and the cases with more increased radiotracer uptake rate in the follow-up $^{99m}Tc$-DMSA renal scans were 20 in number as 69% in frequency. 19 cases with improved renal function on $^{99m}Tc$-DMSA renal scans didn't show any significant difference related to aging or recovery duration after therapy. The $^{99m}Tc$-DMSA renal scans were not useful to evaluate renal function recovery in infants and children, but could be good tests to assess residual renal function prior to or after treatment.

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.84-93
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• 1999

Purpose: We investigated the direct labeling method of antibody with $^{99m}Tc$ and $^{188}Re$ and examined the stability and function of these labeled compounds in in vitro and in vivo. Materials and Methods: Disulfide bond of nonspecific human IgG was reduced to -SH group by 2-mercaptoethanol. Stannous ion was used to reduce $^{99m}Tc$ and $^{188}Re$. The stability of $^{99m}Tc$-IgG and $^{188}Re$-IgG was estimated upto 24 hrs. Biodistribution was evaluated in abscess bearing rats at 4 and 24 hr post-injection of $^{99m}Tc$ or $^{188}Re$ labeled IgG. Results: The number of -SH group per reduced IgG molecule was 2.34. The labeling yield of $^{99m}Tc$-IgG and $^{188}Re$-IgG were 90% and 95%, respectively The stability of $^{99m}Tc$-IgG at 1, 4, 6 and 24 hr was 91%, 83%, 78%, 7% and that of $^{188}Re$-IgG at 1, 4, 16 and 24 hr was 94%, 80%, 47%, 42%, respectively. At 4 hr post-injection of $^{99m}Tc$-IgG, high uptake was found on kidney, blood, stomach and abscess ($9.42{\pm}0.68,\;1.43{\pm}0.24,\;0.86{\pm}0.18,\;0.72{\pm}0.10$ %ID/g, respectively). The uptakes at 24 hr were kidney, abscess,.itomach, and blood in descending order. In case of $^{188}Re$-lgG, high uptake at 4 hr post injection appeared on kidney, blood, abscess and stomach ($3.92{\pm}0.62,\;1.32{\pm}0.08,\;0.88{\pm}0.01,\;0.26{\pm}0.06$, respectively). The uptakes at 24 hr were kidney, abscess, blood and stomach in descending order. The abscess to blood uptake ratio of $^{99m}Tc$-IgG was 0.5 at 4 hr and 2.02 at 24 hr and that of $^{188}Re$-IgG was 0.67 and 1.29. Conclusion: $^{99m}Tc$-IgG and $^{188}Re$-IgG canbe labeled efficiently with direct labeling method. However, $^{99m}Tc$-IgG and $^{188}Re$-IgG, labeled with direct method, was unstable. Further study is needed to enhance the stability of the antibody labeling.

• ETRI Journal
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• v.10 no.3
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• pp.170-178
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• 1988

SS(Signalling System) No.7 신호 방식은 통신망 내의 각 노드들 간에 공통적으로 별도의 채널을 이용하여 회선관련 신호 정보 및 비회선 관련 신호 정보를 교환하는 신호방식이다. SS No.7 신호 방식의 각 계위 프로토콜 중에서 비회선 관련 신호 정보를 교환하기 위하여 상위 프로토콜로 TC(Transaction Capabilities)와 TC-User들을 CCITT에서 권고하고 있다. 본 고에서는 국내에 도입할 SS No.7 신호방식의 하위 프로토콜인 SCCP (Signalling Connection Control Part)와 MTP(Message Transfer Part) 프로토콜의 특성에 따른 TC 및 TC-User 프로토콜의 설계시에 고려되어야 할 사항들을 살펴본다.

• Transactions on Electrical and Electronic Materials
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• v.5 no.4
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• pp.158-160
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• 2004

BiSrCaCuO thick films were fabricated by plasma enhanced chemical vapor deposition, and the crystallinity and the superconducting properties were investigated. The superconductivity was achieved at 20 K with an onset temperature of around 90 K in the film prepared at 72$0^{\circ}C$. From X ray diffraction analysis, the main superconducting phase in the films was the low Tc phase at 700∼75$0^{\circ}C$ and the high Tc phase at 750 ∼ 80$0^{\circ}C$.

• Journal of Korea Water Resources Association
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• v.47 no.12
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• pp.1187-1198
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• 2014

Strong winds and heavy rainfall from tropical cyclones (TCs) that occur in the Northwestern Pacific cause significant human and material damage to the Korean peninsula and East Asia. Hence, it is important to establish early warning systems and conduct preparedness activities in advance of a TC. This study suggests a technique to extract the value of uniform TC-induced rainfall considering the TC track and TC size. To validate our technique, we compare it to existing TC rainfall techniques using the spatial domain. To determine the TC size required for extracting TC-induced rainfall, this research analyzed the mean of TC-induced rainfall by TC size (1973-2012). As a result of this analysis, the maximum amount of mean of TC-induced rainfall was found for a TC with a radius of 700 km. Other techniques have limitations which this new technique addresses; it can extract TC-induced rainfall in each administrative area and minimize systematic biases of other extraction methods. The result of this study can be utilized in the preparation of rainfall forecasts, designing hydraulic structures, and predicting landslide and debris flows using TC-induced rainfall and downpours.

• The Korean Journal of Nuclear Medicine
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• v.37 no.6
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• pp.393-401
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• 2003

Objective: Pullulan derivatives (PD) can be used to make self-assembled hydrogel nanoparticles which are responsive to ionic strength. The aim of this study is to evaluate the potential of PD as a retaining carrier of radioisotope inside tumors. Materials and Methods: Four types of PD were evaluated which included pullulan acetate (PA), succinylated PA (SPA), PA-DTPA and SPA-DTPA conjugates. They were radiolabeled with Tc-99m. Labelling efficiencies were determined at 30 min, 1, 2, 4 and 12 hours after radiolabeling. CT-25 colon cancer cells were subcutaneously injected into Balb/c mice. After 2 weeks of subcutaneous injection, Tc-99m-labelled PD (Tc-99m-PD) were injected into the tumors. Whole body images of mice were obtained at 30 min, 1, 2, and 12 hr after intratumoral injection. All twenty mice were grouped into four groups by largest diameter; control A (largest diameter = 5 mm, n = 5), control B (largest diameter = 10 mm, n = 5), pullulan A (largest diameter = 5 mm, n = 5), pllulan B (largest diameter = 10 mm, n = 5). Dynamic images were obtained for 1 hour after intratumoral injection. Static images were obtained at 1 hr, 2 hr, 3 hr and 4 hr after intratumoral injection with Tc-99m pertechnetate and Tc-99m-PA. Target-to-background ratios and retention rates were calculated. Results: Labeling efficiencies of PA, SPA, PA-DTPA and SPA-DTPA were $94.5{\pm}5.9%,\;97.8{\pm}3.5%\;94.2{\pm}3.8%,\;and\;92.5{\pm}6.2%$, respectively (p>0.05). Percent retention rates (%RR) of PA and PA-DTPA were significantly higher than those of control, however, those of SP-DTPA and SPA became similar to control at 4 and 12 hr, respectively. %RR of pullulan A and pullulan B at 1, 4 and 8 hr is significantly higher than that of control (p < 0.05). However, %RR between pullulan A and pullulan B were similar. Conclusion: The lonic strength dependent PD-nanoparticles are retained in the tumor. No difference of %RR according to tumor size was noted. Therapeutic application of PD labelled with beta- or alpha- emitting radionuclides can be expected.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.270-276
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• 1993

$Technetium-^{99m}$ labeling method using bifunctional chelating agent cyclic DTPA has been evaluated with human polyclonal nonspecific IgG. IgG was conjugated with cyclic DTPA with various molar ratio. Reduction of $^{99m}Tc$ was done with $Na_2S_2O_4$ with various molar excess. Labeling efficiency and identification of polymer was confirmed with HPLC using TSK4000 SW column. Polymer was purified with 100 cm Sepharose 6LB column. Cultured $1{\times}10^9$ Staphylococcus aureus were injected into rat thigh 24 hours later labeled IgG was injected, and in vivo distribution was observed 4 and 24 hours thereafter. Reduction of $^{99m}Tc$ was optimal with the 10000-50000 times molar excess of $Na_2S_2O_4$. Polymer formation increased with increasing mloar excess of cyclic DTPA to IgG. Three step labeling-labeling DTPA conjugated IgG after reduction of $^{99m}Tc$-made more polymer than two two step labeling-simultaneous mixing DTPA conjugated IgG, $^{99m}Tc$ and $Na_2S_2O_4$. $^{99m}Tc$ blood clearance and lower uptake in the abscess and other organs. IgG conjugated with 200 times molar excess of cyclic DTPA showed slower blood clearance with 200 times molar excess of cyclic DTPA showed slower blood clearance than that of 200 times molar excess of cyclic DTPA showed slower blood clearance than that of 20 times molar excess. In the $^{99m}Tc$ labeling of IgG with cyclic DTPA for the immunoscintigraphy, obtimal labeling condition should be chosen, and effect of the $^{99m}Tc$ labeled IgG polymer should be considered.