• 한국정밀공학회지
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• 제24권1호
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• pp.110-117
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• 2007

This study investigated changes of mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae of the ovariectomised (OVX) rat. In previous researches, there were many studies for morphology of osteoporotic bones based on Micro-Computed Tomography (Micro-CT). However, there were few studies for detecting and tracking changes of mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae of the OVX rat. For this study, the 4th lumbar of the OVX rat (female Sprague-Dawley) was utilized as a specimen. An OVX rat was scanned at week 0 (just before surgery), at week 4, and week 8 after surgery. Micro-finite element (${\mu}-FE$) analysis was used to investigate mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae for an OVX rat. When the OVX rat (at week 8) was compared with the OVX rat (at week 0), the structural modulus of cortical and trabecualr bone was decreased by 52% and 99%, respectively. This study showed the change of mechanical characteristics of cortical bone as well as trabecular bone of an OVX rat. Detecting and tracking changes of mechanical characteristics could greatly contribute to an experiment test for the trabecular and cortical bone in the lumbar vertebrae of an OVX rat by using In-vivo Micro-CT.

• 한국치위생학회지
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• 제1권2호
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• pp.171-180
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• 2001

The purpose of this study was to compared with the properties of commercial polyvinyl siloxane impression materials on the Korean product and the other country one. The materials used in this study were 5 hydrophilic polvinyly siloxane impression materials of light body automixing type (Perfect-F, Handae Chemical, Korea; Examix, GC, Japan; Contrast, VOCO, Germany; Express, 3M, U.S.A; Extrude, Kerr, U.S.A.). Specimens of each impression material were fabricated from a mold with dimensions identical to that specified in ASTM D624-91 and were subjected to tensile lode at 500 mm/min until failure for tear strength. Properties of consistency, strain in compression, recovery from deformation, detail reproduction and linear dimensional change were tested according to the testing methods of the ISO specification no.4823(1992). From this study, the follow ing results were obtained 1. The tear strength values were high ET(3.4kN/m), EP(3.4kN/m), PF(3.0kN/m), CT(3.0kN/m), but the lowest was EM(2.2kN/m)(p<0.05). 2. In the consistency, CT(47 mm) had the highest value, followed by PF(42.1 mm), ET(41.2 mm), and EM(39.6 mm), EP(39.2 mm)(p<0.05). It means more flow that the consistency value is high. 3. The strain in compression values were high followed by EM(5.8%), PF(52%), CT(4.6%), ET(4.1%), EP(2.9%)(p<0.05). 4. In the recovery from deformation, ET(99.95%) and PF(99.90%) had the highest value, followed by EP(99.75%), EM(99.74%) without statistical signification, CT(99.64%) had the lowest value(p<0.05). 5. Detail reproduction reappeared to line $20{\mu}m$ all products. 6. The linear dimensional change was a little shrinked all products. and there were not statistical signification (p>0.05). All products were satisfied the ISO specification.

• Journal of Radiation Protection and Research
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• 제43권4호
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• pp.154-159
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• 2018

Background: To prevent small leakage accidents, a real-time and direct detection system for small leaks with a detection limit below that of existing systems, e.g. $0.5gpm{\cdot}hr^{-1}$, is required. In this study, a small-size beta detector, which can be installed inside the reactor containment (CT) building and detect small leaks directly, was suggested and its feasibility was evaluated using MCNPX simulation. Materials and Methods: A target nuclide was selected through analysis of radiation from radionuclides in the reactor coolant system (RCS) and the spectrum was obtained via a silicon detector simulated in MCNPX. A window was designed to reduce the background signal caused by other nuclides. The sensitivity of the detector was also estimated, and its shielding designed for installation inside the reactor CT. Results and Discussion: The beta and gamma spectrum of the silicon detector showed a negligible gamma signal but it also contained an undesired peak at 0.22 MeV due to other nuclides, not the $^{16}N$ target nuclide. Window to remove the peak was derived as 0.4 mm for beryllium. The sensitivity of silicon beta detector with a beryllium window of 1.7 mm thickness was derived as $5.172{\times}10^{-6}{\mu}Ci{\cdot}cc^{-1}$. In addition, the specification of the shielding was evaluated through simulations, and the results showed that the integrity of the silicon detector can be maintained with lead shielding of 3 cm (<15 kg). This is a very small amount compared to the specifications of the lead shielding (600 kg) required for installation of $^{16}N$ gamma detector in inside reactor CT, it was determined that beta detector would have a distinct advantage in terms of miniaturization. Conclusion: The feasibility of the beta detector was evaluated for installation inside the reactor CT to detect small leaks below $0.5gpm{\cdot}hr^{-1}$. In future, the design will be optimized on specific data.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 춘계 학술발표대회
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• pp.102-102
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• 2003

The present study has been undertaken to characterize availability of camellia(Camellia japonica L.) as a medicinal plant with antineoplastic and chemosensitizing activities. The crude extracts from fresn camellia flower, young leaves and nutraceutical tea of camellia leaf and flower buds were evaluated on their potential activities against various human cancer cells and multidrug resistance to cancer cells in vitro. The range of cytotoxicity displayed from 120$\mu\textrm{g}$/mL to 200$\mu\textrm{g}$/mL. Catemix 1(CT-1) mixed with camellia and green tea showed high toxicity(respectively IC$\sub$50/=l16$\mu\textrm{g}$/mL, 129$\mu\textrm{g}$/mL) against AML-2/WT, acute myelogenous leukemia cell and MCF-7, brest adenocarcinoma pleual effusion cell. Generally camellia tea mixed with green tea showed higher cytotoxicity than the other camellia teas mixed with some herbs(CH). Methanol extract of steamed camellia tea and roasted camellia tea had a chemosensitizing effect to reverse Pgp-mediated MDR. In addition, camellia flower tea of insignificant cytotoxicity, chemosensitizing effect were increased remarkably chemosensitizing effect in mixed flower tea with some herbs.

• 핵의학기술
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• 제22권2호
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• pp.97-100
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• 2018

Glomerular filtration rate (GFR)검사는 사구체의 여과기능을 나타내는 중요한 지표로서 신장기능과 그 기능의 정도를 검사하기 위하여 시행되고 있다. 사구체의 혈액 여과 작용은 신장의 중요한 기능 중 하나로 여과 장벽을 구성하여 체내에 필요한 혈구와 단백질은 빠져나가지 못하게 하고 크기가 작은 물질이나 수분, 노폐물은 자유롭게 통과시킨다. 하지만 사구체의 여과기능이 제대로 이루어 지지 않을 경우 혈뇨 및 단백뇨가 검출된다. 이와 같이 사구체의 기능에 문제가 있을 경우 급성 사구체 신염, 만성 사구체 신염 등 신장질환이 발생하게 되고 GFR검사를 통해 사구체 기능의 정도를 판단하고 있다. GFR검사는 $^{51}Cr$-EDTA으로 방사선의약품을 만들어 정맥주사를 하고 경과시간에 따라 EDTA Tube에 채혈하여 Plasma 내 방사능을 측정하여 결과 값을 도출해 낸다. 따라서 진료과 및 병동에 통보하여 동위원소를 사용하는 PET-CT, Bone Scan과 혈액에 영향을 주는 투석 및 수혈은 GFR검사와 병행하지 않도록 사전에 통보하고 있다. 검사방법으로는 먼저 $^{51}Cr$-EDTA 2 mL와 생리식염수 5 mL를 잘 혼합하고 혼합된 용액 중 5 mL로 환자에게 주입 할 방사성 의약품을 만든다. 먼저 주사 전 주사무게를 측정하고 환자의 정맥에 주사를 시행하고 난 뒤 주사 후 주사무게를 측정한다. 채혈은 총 2번 시행되고 성인의 경우에는 주입 후 3시간, 5시간 뒤, 소아의 경우 주입 후 2시간, 5시간 뒤 EDTA Tube에 5 mL채혈한다. 채혈 된 검체는 3300rpm에 5분간 원심분리 시키고 Plasma $500{\mu}L$를 Test tube에 분주하여 Sample rack에 준비해 둔다. Standard용액 제조방법은 200 mL Volumetric flask에 표시된 눈금까지 Diluent water를 채워주고 난 후 $500{\mu}L$을 버리고 $^{51}Cr$-EDTA $500{\mu}L$를 주입한 후 잘 혼합해준다. 제조 된 Standard 용액은 2개의 Test tube에 각각 $500{\mu}L$씩 분주하고 측정대상인 환자의 Plasma와 함께 Gamma Counter로 계측한다. 계측으로 얻은 CPM과 환자의 신장, 체중, 주사 전 후 무게 등을 GFR함수식에 입력하여 결과 값을 도출해 낸다. Reference range는 남성은 $119.5{\pm}30.3ml/min/1.73m^2$ 이고 여성은 $125.2{\pm}28.2ml/min/1.73m^2$ 설정되어 있지만 본원에서는 성별에 관계없이 $97.0ml/min/1.73m^2$ 이상일 경우 신장이식이 가능하다고 판단하고 있다. GFR검사 결과 값에 따라 신장기능의 정도가 반영 되기 때문에 병행하지 않아야 할 검사들과 주의사항을 준수한다면 보다 더 신뢰할 수 있는 결과 값을 얻을 수 있을 것이라 생각한다.

• The Journal of Advanced Prosthodontics
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• 제6권4호
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• pp.253-258
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• 2014

PURPOSE. To compare marginal and internal gaps of zirconia substructure of single crowns with those of three-unit fixed dental prostheses. MATERIALS AND METHODS. Standardized Co-Cr alloy simulated second premolar and second molar abutments were fabricated and subsequently duplicated into type-III dental stone for working casts. After that, all zirconia substructures were made using $Lava^{TM}$ system. Marginal and internal gaps were measured in 2 planes (mesial-distal plane and buccal-palatal plane) at 5 locations: marginal opening (MO), chamfer area (CA), axial wall (AW), cusp tip (CT) and mid-occlusal (OA) using Replica technique. RESULTS. There were significant differences between gaps at all locations. The $mean{\pm}SD$ of marginal gap in premolar was $43.6{\pm}0.4{\mu}m$ and $46.5{\pm}0.5{\mu}m$ for single crown and 3-unit bridge substructure respectively. For molar substructure the $mean{\pm}SD$ of marginal gap was $48.5{\pm}0.4{\mu}m$ and $52.6{\pm}0.4{\mu}m$ for single crown and 3-unit bridge respectively. The largest gaps were found at the occlusal area, which was $150.5{\pm}0.5{\mu}m$ and $154.5{\pm}0.4{\mu}m$ for single and 3-unit bridge premolar substructures respectively and $146.5{\pm}0.4{\mu}m$ and $211.5{\pm}0.4{\mu}m$ for single and 3-unit bridge molar substructure respectively. CONCLUSION. Independent-samples t-test showed significant differences of gap in zirconia substructure between single crowns and three-unit bridge (P<.001). Therefore, the span length has the effect on the fit of zirconia substructure that is fabricated using CAD/CAM technique especially at the occlusal area.

• 한국자기학회지
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• 제6권6호
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• pp.388-396
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• 1996

원심분무(centrifugal atomization)법 제조 분말로 제작된 Fe-79Ni-4Mo 소결코아의 자기특성을 조사하였다. 소결코아의 60 Hz, 10 Oe의 교류자기장에서 측정된 $H_{c}$ 및 $\mu_{a}$ 특성은 $1350^{\circ}C$, 2시간의 소결조건에서 최고를 나타내었으며, 원료분말의 입도가 증가할수록 약 0.2 Oe 이하 약한 자기장하에서 $H_{c}$, $\mu_{a}$ 특성은 양호하였다. 이는 소결체의 결정입경에 의존하는 자벽이동에 기인하였다. 얻어진 최고의 직류자기특성은 $H_{c}$와 $\mu_{max}$가 각각 0.085 Oe, 4000 이었고, 교류자기특성은 $\mu_{a}$가 11000 이었다. 한편, 이와같은 연자기 특성은 서로 다른 입도의 분말을 혼합함으로써 더욱 개선실 수 있었다. 본 연구에서 개발된 코아의 자기특성은 CT(current transformer)용 전류센서에서의 응용될 것으로 기대된다.

• 대한방사선방어학회:학술대회논문집
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• 대한방사선방어학회 2011년도 추계 학술발표회 및 심포지엄
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• pp.98-99
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• 2011

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2007년도 추계학술발표대회
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• pp.101-103
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• 2007

혈관 구조는 사람의 가장 복잡한 구조 중 하나이다. 혈관 분석에는 Morphology and Topology 가 있다. 우리는 목표는 위 분석 기법과는 달리 3D 영상 재구성이다. 본 논문은 Raw CT data 을 세그먼트하고 Skeleton line 을 인용하여 복잡한 트리 형태의 혈관 3D 재구성을 하였다.

• 한방재활의학과학회지
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• 제24권2호
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• pp.65-81
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• 2014

Objectives This study was carried out to find out the anti-osteoarthritic effects of Mahwangbujaseshin- tang (Mahuangfuzixixintang ) on the monosodium iodoacetate (MIA)-induced osteoarthritis rats. Methods Osteoarthritis was induced by injecting MIA ($50{\mu}l$) into the knee joint of rats. Rats were divided into a 3 groups (n=7). The injection did not fit the normal group. A week later, after the injection of MIA, while control group took normal saline 2 ml, the extract of Mahwangbujaseshin-tang (Mahuangfuzixixintang ) (MBST) (200 mg/kg) was injected to treated group. After that, we examined hind paw weight bearing ability, functions of liver and kidney, serum TNF-$\alpha$, IL-$1{\beta}$, IL-6, $PGE_2$, $LTB_4$, TIMP-1, MMP-9 and hematology. Volume of cartilage was measured by micro CT arthrography. Injury of synovial tissue was measured by H & E, Safranin-O immunofluorescence. Results 1) DPPH and ABTS free radical scavenging activity of MBST was increased according to concentration of MBST and total phenolic contents were in high level. 2) In RAW 264.7 cells, ROS production was significantly decreased in MBST (at 10, $100{\mu}g/ml$) and NO was also decreased but meaningless in MBST (at $100{\mu}g/ml$). 3) In RAW 264.7 cells, IL-6 production was significantly decreased in MBST (at $100{\mu}g/ml$) and TNF-$\alpha$ and IL-$1{\beta}$ production were also decreased but meaningless in MBST (at $100{\mu}g/ml$). 4) In hind legs weight-bearing measurement, level of weight-bearing was increased. 5) Functions of liver and kidney were not affected. 6) TNF-$\alpha$, IL-$1{\beta}$, IL-6, $PGE_2$, $LTB_4$, MMP-9 and TIMP-1 production were significantly decreased. 7) In hematology, the levels of neutrophils, monocytes were significantly decreased and the levels of white blood cells, lymphocytes were also decreased but meaningless. 8) In micro CT-arthrography, cartilage volume was significantly increased. 9) Histopathologically, injury on cartilage and synovial membrane of MBST group was decreased. Conclusions Based on all results mentioned above, Mahwangbujaseshin-tang (Mahuangfuzixixintang) is believed to be meaningful for suppressing the progress of osteoarthritis. And it is related to inhibiting the activity of inflammatory cytokine and injury of volume in cartilage.