• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.99.3-99
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• 1998

• IMMUNE NETWORK
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• v.1 no.1
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• pp.53-60
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• 2001

Background: The human mic2 gene is a pseudoautosomal gene that encodes a cell surface antigen, CD99. High levels of CD99 constitute a tumor marker in Ewing s sarcoma (ES). We have recently demonstrated that CD99-induced apoptosis occurs only in undifferentiated ES cells, not in differentiated ES cells, raising the possibility of the involvement of CD99 in neural ontogeny. Methods: To elucidate the relations between the expression of CD99 and the differentiation of neural cells and the mechanism by which the expression of CD99 is regulated, we analyzed the differential patterns of CD99 expression in SH-SY5Y by treatment of 12-O-tetradecanoyl-13-phorbol acetate (TPA) and retinoic acid. In addition, to explore the transcriptional activity of CD 99 during neural cell differentiation, SH-SY5Y cells were transiently transfected with a CD99 promoter-driven luciferase construct, and treated with the inducers. Results: In immunoblotting and flow cytometry, the expression level of CD99 was increased on differentiated SH-SY5Y cells induced by TPA and retinoic acid. The luciferase activity was elevated by the treatment with TPA, known to mature SH-SY5Y cells toward a sympathetic neuronal lineage, whereas retinoic acid inducing a sympathetic chromaffin lineage displayed little effect. Conclusion: The result indicates that CD99 might be expressed only on cells maturing toward a neuronal lineage among differentiating primitive neuronal cells. In addition, the expression of CD99 seems to be regulated at the transcriptional level during the differentiation.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1517-1523
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• 2020

The widely used medical isotope technetium-99 m (^99mTc) is a daughter of Molybdenum-99 (⁹⁹Mo), which is mainly produced using dedicated research reactors from the nuclear fission of uranium-235 (²³⁵U). ^99mTc has been used for several decades, which covers about 80% of the all the nuclear diagnostics procedures. Recently, the instability of the supply has become an important topic throughout the international radioisotope communities. The aging of major ⁹⁹Mo production reactors has also caused frequent shutdowns. It has triggered movements to establish new research reactors for ⁹⁹Mo production, as well as the development of various ⁹⁹Mo production technologies. In this context, a new research reactor project was launched in 2012 in Korea. At the same time, the development of fission-based ⁹⁹Mo production process was initiated by Korea Atomic Energy Research Institute (KAERI) in 2012 in order to be implemented by the new research reactor. The KAERI process is based on the caustic dissolution of plate-type LEU (low enriched uranium) dispersion targets, followed by the separation and purification using a series of columns. The development of proper waste treatment technologies for the gaseous, liquid, and solid radioactive wastes also took place. The first stage of this process development was completed in 2018. In this paper, the results of the hot test production of fission ⁹⁹Mo using HANARO, KAERI's 30 MW research reactor, was described.

• Proceedings of the KSCN Conference
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• 2005.10a
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• pp.99-99
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• 2005

• Bulletin of the Korean Space Science Society
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• 2007.10a
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• pp.99.1-99.1
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• 2007

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.17-26
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• 2012

Purpose: This study mainly focuses on the patients treated with chemically stable radiopharmaceutical product $^{99m}Tc$-HMPAO (d,l-hexamethylpropylene amine oxime) which yielded reduced image quality due to a decreased brain extraction rate. $^{99m}Tc$-HMPAO will be examined further to determine whether this product may be accounted as a factor for this cause. Material and Methods: From January 2010 until December 2010, out of 272 patients who were all subjected to $^{99m}Tc$-HMPAO brain blood flow SPECT scans resulting from Cerebral Infarction; 23 patients(ages $55.3{\pm}9$, 21 males, 3 females) with decreased tissue extraction rate were examined in detail. The radiopharmaceutical product $^{99m}Tc$-HMPAO was used on patients with normal brain tissue exchange rate as well as those with reduced rate in order to prove its' chemical stability. The patients' age, sex, blood pressure, existence of diabetes, drug use, current health status, known side effects from CT/MRI, examination of the patients' past SPECT before/after images were accounted to determine the factors and correlations affecting the rate of blood tissue extractions. Result: After multiple linear regression analysis, there were no unusual correlations between the 6 factors excluding sex, and before/after examination images. Male subjects showed reduced brain tissue extraction rate than the females ($p$ > 0.05) 91.3% male, 8.7% female. Wilcoxon Matched-Pairs Signed-Ranks Test was used on the before/after images which yielded a value of 0.06, which did not indicate a significant amount of difference on the 2 tests ($p$ > 0.05). As a result, the before/after images indicated similar brain tissue extraction rates, and there were variations depending on the individual patient. Conclusion: The effects of the chemically stable radiopharmaceutical product $^{99m}Tc$-HMPAO depended on the patient's personal characteristics and status, therefore was considered to be a factor in reducing brain tissue extraction rate. The related articles of $^{99m}Tc$-HMPAO cerebral blood flow SPECT speculates a cerebrovascular disease and factors resulting from portal veins, and it was not possible to pin point the exact cause of decreasing brain tissue extraction rate. However, the $^{99m}Tc$-HMPAO cerebral blood flow SPECT scan proved to be extremely useful in tracking and inspecting brain diseases, as well as offering accurate results from patients suffering from reduced brain tissue extraction rates.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.1
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• pp.48-50
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• 2006

A 38-year-old female with arthralgia in right elbow joint for 6 months was referred for a bone scan which showed diffuse uptakes of $^{99m}Tc$-MDP in the liver and spleen without hepatosplenomegaly. She had a history of hepatitis B vaccination 3 days ago. These uptakes were disappeared on the follow-up bone scan after 4 months. We suggest this transient diffuse hepatic uptake after vaccination of hepatitis B might be due to aluminum component within the hepatitis B vaccine as adjuvant.

• The Korean Journal of Nuclear Medicine
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• v.36 no.6
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• pp.325-332
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• 2002

Purpose: Human Na+/I- symporter (hNIS) is known to be expressed in many tissues other than thyroid gland. The breast cancer cells are one of them and the possibility of radioiodine therapy in treatment of the breast cancer may be suggested. We investigated the expression rate of hNIS and the relationship between the expression of hNIS and the finding of 99mTc-MIBI scintimammographv in the breast cancer Materials and Methods: Surgically proved 56 patients with breast cancer were the subjects of this study The expression of hNIS were evaluated by immunohistochemistry and the results were compared to the findings of 99m7c-MIBI scintimammography. Results: Overall expression rate of hNIS was 41.1% in 56 patients. According to the pathologic diagnosis, it was 42.9% in 49 patients with invasive ductal carcinoma and 28.6% in the 7 patients with ductal carcinoma in situ. The expression rate of hNIS in the 41 cases with a focal increased uptake at he breast lesion on 99m7c-MIBI sointimammogram was 31.7%. That in the 15 cases without any abnormal uptake on the scan was significantly higher(65.7%, p<0.05). Conclusion: The expression rate of hNIS in the patients with breast cancer was not so high. The rate was higher in the patients with no increased uptake at the breast lesion on 99m7c-MIBI scintimammography.

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.57-64
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• 1999

Purpose: The purpose of this study was to evaluate the accuracy of Tc-99m DTPA diuretic renal scans in children with dilated upper urinary tract. Materials and Methods: We reviewed diuretic renal scans of 14 pediatric patients (age range: 3 days to 4 years) with unilateral hydronephrosis diagnosed by ultrasonography. Diuretic renal scan was done using Tc-99m DTPA and standardized protocol. In 3 neonates, diuretic renal scans were performed within 1 week and 3-7 months after birth. Results: Six patients required Pyeloplasty and eight were managed conservatively. All 6 patients requiring Pyeloplasty were diagnosed as having ureteropelvic junction obstruction in the diuretic renal scan. In these 6 patients, post-operative renal scans at 3-12 months after surgery were converted to nonobstructive pattern in 5 and a nonfunctioning pattern in 1. In 3 patients who underwent diuretic renal scan within 1 week after birth, nonobstructive patterns of initial scan were converted to obstructive patterns in the follow-up scan. However, all patients with nonobstructive diuretic renal scans performed after the neonatal period did well on serial ultrasonography and showed favorable clinical outcome without progression to obstruction. Conclusion: Tc-99m DTPA diuretic renal scan with standardized protocol is useful in assessing suspected ureteropelvic junction obstruction in children as an initial diagnostic or post-operative follow-up modality. Nonobstructive or indeterminate scan results in the neonatal period requires follow-up scan to monitor development of the obstructive pattern.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.2
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• pp.73-78
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• 2020

Musculoskeletal disease is often caused by sitting down for long period's time or by bad posture habits. In order to prevent musculoskeletal disease in daily life, it is the most important to correct the bad sitting posture to the right one through real-time monitoring. In this study, to detect the sitting information of user's without any constraints, we propose posture measurement system based on multi-channel pressure sensor and CNN model for classifying sitting posture types. The proposed CNN model can analyze 5 types of sitting postures based on sitting posture information. For the performance assessment of posture classification CNN model through field test, the accuracy, recall, precision, and F1 of the classification results were checked with 10 subjects. As the experiment results, 99.84% of accuracy, 99.6% of recall, 99.6% of precision, and 99.6% of F1 were verified.