• 핵의학기술
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• 제16권2호
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• pp.131-134
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• 2012

핵의학검사에서 방사성의약품의 표지효율은 검사의 정확성과 신뢰성 측면에서 중요하다. 보통 Brain SPECT검사에 사용되는 $^{99m}Tc$-HMPAO는 화학적으로 불안정하고 불순물의 발생이 많아 표지효율의 저하가 나타나기 쉽다. 이에 본 연구는 $^{99m}Tc$-HMPAO의 표지효율에 영향을 미치는 인자에 대한 실험을 통해 $^{99m}Tc$-HMPAO 표지 및 사용에 도움이 되고자 한다. Brain SPECT에 사용되는 국산 동아제약의 HMPAO vial을 대상으로 실험하였다. 삼영사의 generator 55.5 GBq (1,500 mCi)를 이용하였고, TLC 측정세트(ITLC-SG, butanone, saline, TLC chamber)와 Radio-TLC 스캐너(Bioscan, AR-2000)를 이용하였다. 첫 번째 실험은 generator에서 1, 8, 16, 24, 28시간 간격을 두고 용출한 $^{99m}Tc$-pertechnetate를 각각 HMPAO와 표지하여 표지효율을 측정하였다. 두 번째 실험은 generator에서 용출한 $^{99m}Tc$-pertechnetate를 0, 1, 3, 6시간경과에 따라 1.85GBq (50mCi)/1 ml를 취하여 HMPAO와 표지하여 표지효율을 측정하였다. 세 번째는 $^{99m}Tc$-HMPAO를 표지 후 0, 30분, 3시간, 5시간, 7시간이 경과했을 때 표지효율을 측정하였다. 첫 번째 실험에서 표지효율은 시간 순으로 95.05%, 94.64%, 94.94%, 95.64%, 96.76%로 나타났다. 두 번째 실험에서는 94.38%, 94.23%, 93.26%, 91.03%로 나타났다. 세 번째 실험에서는 95.76%, 94.17%, 88.19%, 83.6%, 76.86%로 나타났다. 첫 번째 실험에서 generator에서 24시간 후에용출한 $^{99m}Tc$-pertechnetate를 사용 한 표지효율은 비교적 높게 측정되었다. 추가실험을 통하여 임상에서의 사용 가능성에 대한 논의가 필요할 것으로 사료된다. 두 번째 실험에서 시간이 지날수록 표지효율은 다소 감소하였으나 6시간 이후에도 91% 이상으로 높게 측정되었다. 보충실험을 통하여 보완이 필요할 것으로 판단된다. 세 번째 실험에서 시간이 흐를수록 표지효율은 급격하게 감소하였다. 특히, 정확한 검사를 위해 표지후 3시간 이내에 사용하는 것이 좋다고 판단된다.

• 대한음성학회지:말소리
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• 제66호
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• pp.21-39
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• 2008

The purpose of this study is to analyze the intonational slope characteristics of the Korean news utterances. Prosodic phrases were analyzed in terms of the K-ToBI labeling system. In addition, the change of intonation contour that occurs throughout the sentences was discussed in terms of types of media and gender. Results showed that the overall declination of the intonation contour of radio and male revealed a gentler slope than that of TV and female, respectively. While the regression of the top line slope showed male's higher $R^2$ with the number of words, the base line slope of the radio and female was proved to be highly influenced from the number of syllables, words, and prosodic phrases. A lot more independent variables statistically affected to the base line slope. This means that the base line slope was strongly related to the variables, the top line slope, otherwise, could be more freely fluctuated due to the light correlation with them.

• 한국항행학회논문지
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• 제12권3호
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• pp.280-285
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• 2008

기존의 얼굴 검출 방법은 프레임 간의 차를 이용하여 움직임을 검출하는 방법이 사용되어 왔다. 그러나, 대부분이 실시간을 고려하지 않은 수학적 접근법을 사용하거나 알고리즘이 지나치게 복잡하여 실시간 구현에 용이하지 않았다. 본 논문에서는 실시간 얼굴검출을 위하여 감시카메라에서 입력된 RGB영상을 YCbCr 영상으로 변환한 후 연속된 두 영상의 차를 구하고 Glassfire 라벨링을 실시했다. 라벨링 결과 가장 넓은 구역의 면적과 Area 임계치 값을 비교하여 임계값 이상의 면적이면 동작변환으로 인식하고 영상을 추출하였다. 이렇게 추출된 동작변환 영상을 대상으로 얼굴 검출을 실시하였다. 얼굴 검출에 필요한 특징을 추출하기 위해 아다부스트 알고리즘을 사용하였다.

• 대한방사성의약품학회지
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• 제4권1호
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• pp.3-10
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• 2018

The folate receptor (FR) is a promising cell membrane-associated target for nuclear imaging of various cancers (via imaging $FR-{\alpha}$) and potentially also inflammatory diseases (via imaging $FR-{\beta}$), through the use of folic acid-based radioconjugates. However, there have been several drawbacks of previously reported radioconjugates, such as a short half-life of the radiolabel ($^{68}Ga\;t_{1/2}$ 68 min), a complex and time-consuming multistep radiosynthesis, and a high renal uptake of radiolabeled folate derivatives. The goal of this study was to develop an imaging probe by directly labeling folate with radioactive iodine without using an extra prosthetic group. The radiolabeling of folate was optimized using various labeling conditions and the labeled tracers were isolated by high-performance liquid chromatography. The in vitro stability of labeled folate was checked in phosphate-buffered saline and serum. The tumor-targeting efficacy of the probe was also evaluated by biodistribution studies using a murine 4T1 tumor model.

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.71-76
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• 2011

An efficient nucleophilic [$^{18}F$]fluorination has been studied to reduce byproducts and preparation time. Instead of conventional aqueous solution of $K_2CO_3-K_{222}$, several organic solution containing inert organic salts were used to release [$^{18}F$]fluoride ion and anion bases captured in the polymer cartridge, concluding that methanol solution is the best choice. Comparing to azeotropic drying process, one min was sufficient to remove methanol completely, resulting in about 10% radioactivity saving by reducing drying time. The polymer cartridge, Chromafix$^{(R)}$ (PS-$HCO_3$) was pretreated with several anion bases to displace pre-loaded bicarbonate base. Phosphate bases showed better results than carbonate bases in terms of lower basicity. tert-Butanol solvent used as a reaction media played another critical role in nucleophilic [18F]fluorination by suppressing eliminated side product. Consequent [$^{18}F$]fluorination under the present condition afforded fast preparation of reaction solution and high radiochemical yields (98% radio-TLC, 84% RCY) with 94% of precursor remained.

• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.13.1-13.4
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• 2016

An analysis of patients and fatalities due to exposure to polyhexamethylene guanidine (PHMG) shows that PHMG causes mainly lung diseases such as pulmonary fibrosis. However, no research on the other organs has been conducted on this matter yet. So, an in-depth discussion on toxicological techniques is needed to determine whether or not PHMG is toxic to organs other than just the lungs. For the test of target organ toxicity by PHMG exposure, a toxicokinetic study must first be conducted. However, measurement method for PHMG injected into the body has not yet been established because it is not easy to analyze polymer PHMG, so related base studies on analytical technique for PHMG including radio-labeling chemistry must come first. Moreover, research on exposure-biomarker and effect-biomarker must also be conducted, primarily related to clinical application. Several limitations seem to be expected to apply the biomarker study to the patient because much time has passed after exposure to the humidifier disinfectant. It is why a more comprehensive toxicological researches must be introduced to the causality for the victims.

• 한국경영정보학회:학술대회논문집
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• 한국경영정보학회 2007년도 International Conference
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• pp.951-958
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• 2007

Radio Frequency Identification (RFID) is a technology for automated identification of objects and people. RFID may be viewed as a means of explicitly labeling objects to facilitate their "perception" by computing devices. RFlD systems have been gaining more popularity in areas especially in supply chain management and automated identification systems. However, there are many existing and potential problems in the RFlD systems which could threat the technology s future. To successfully adopt RFID technology in various applications. we need to develop the solutions to protect the RFID system s data information. This study investigates important issues related to privacy and security of RF1D based on the recent literature and suggests solutions to cope with the problem.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2007년도 한국음성과학회 공동학술대회 발표논문집
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• pp.197-200
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• 2007

The purpose of this study is to analyze the prosodic characteristics of Korean news utterances. In this paper, prosodic phrases were described in terms of the K-ToBI labeling system. In addition, the change of intonation contour that occurs throughout the sentences was discussed in terms of types of media and gender. According to analyzing the tendency of resets, 331 out of 729 resets were observed at the boundary of the intonation phrases. This means that resets are of the speaker's own volition regardless of prosodic units of intonation phrases. The declination of the intonation contour of radio news showed a gentler slope than that of TV news, because when the sentence is getting longer, the declination of the intonation contour becomes slower.

• 대한방사성의약품학회지
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• 제1권1호
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• pp.46-52
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• 2015

Herein we present the synthesis of $^{68}Ga$-labeled gold nanoparticles for in vivo PET imaging. A novel chelator DTPA-Cys was easily prepared from diethylenetriaminepentaacetic dianhydride in high yield. The ${\alpha}_v{\beta}_3$ integrin receptor targeted gold nanoparticle probe was synthesized by using DTPA-Cys, polyethylene glycol and cRGD peptide. $^{68}Ga$ labeling of cRGD conjugated gold nanoparticle was carried out at $40^{\circ}C$ for 30 min. Observed radiochemical yield was more than 75% as determined by radio-TLC and the probe was purified by centrifugation. In vitro stability test showed that 90% of $^{68}Ga$-labeled gold nanoparticle probe was stable in FBS for 1 h. Those results demonstrated that $^{68}Ga$-labeled gold nanoparticle could be used as a potentially useful probe for specific tumor imaging.

• Nuclear Medicine and Molecular Imaging
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• 제40권2호
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• pp.66-73
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• 2006

Monoclonal antibodies are designed to bind specifically to certain antigen, give therapeutic effect to the target and to be produced in large scale with homogeneity. The monoclonal antibodies conjugated with radionuclide can deliver therapeutic irradiation to the target, and showed successful results in certain malignancies, which is known as radioimmunotherapy. The target-to-background ratio depends on the antigen expression in the target and normal tissues, which is related to the therapeutic efficacy and toxicity in radioimmunotherapy. For the solid tumor beta-ray energy should be high, but lower beta energy is better for the hematological malignancies. I-l31 is widely used in thyroid cancer with low cost and high availability. Labeling monoclonal antibody with I-131 is relatively simple and reproducible. Some preclinical data for the I-131 labeled monoclonal antibodies including acute toxicity and efficacy are available from already published literatures in KIRAMS, physician sponsored clinical trial protocols using Rituximab, KFDA approved anti-CD20 chimeric monoclonal antibody and I-131 were approved by KFDA and currently are ongoing.