• 대한기계학회논문집B
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• 제32권4호
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• pp.241-248
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• 2008

The purpose of the research is to investigate of diesel spray combustion for simultaneously reduction way of NOx and PM. The diesel injection were done into intermediates that are generated by very lean DME HCCI combustion using a RCM. The concentration of intermediate could not be directly measured, so we estimated it by CHEMKIN calculation. Two dimensional spontaneous luminescence images which are created by chemical species reaction at low temperature reaction (LTR) and high temperature reaction (HTR) are captured by using a framing streak camera. Also, combustion events were observed by high-speed direct photography. The ignition and combustion events were analyzed by pressure profiles and the KL values and flame temperatures were analyzed by the two-color method.

• 한국식품영양과학회지
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• 제33권7호
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• pp.1119-1125
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• 2004

콩 식이섬유로부터 제조한 헤미셀룰로즈가 streptozotocin으로 유발한 당뇨쥐의 혈당과 혈청콜레스테롤함량에 미치는 영향을 조사하였다. 실험군은 셀룰로즈군(대조군), 헤미셀룰로즈 0.5% 식이군(H-1군), 헤미셀룰로즈 1% 식이군(H-2군)으로 나누어 6주간 사육한 후 당뇨를 유발시키고 계속해서 1주간 사육하였다. 당뇨유발에 따른 식이섭취량과 체중증가량 및 식이효율은 H-2식이군이 대조군과 H-1군에서 보다 높은 값을 나타낸 반면 음용수 섭취량은 H-2군에서 낮았다. 간장의 무게는 H-2군이 대조군과 H-1군에 비하여 유의적으로 낮았다. 혈당은 대조군에서는 212.8 mg/dL, H-1 군에서는 160.5 mg/dL, H-2군에서 는 141.0 mg/dL으로 H-2군은 대조군의 66%수준이었으며 뇨당은 대조군 0.97 mg/dL, H-1군 0.53 mg/dL, H-2군 0.35 mg/dL로 H-1군은 대조군의 55%, H-2군은 대조군의 36%로 헤미셀룰로즈 식 이군이 대조군에 비하여 유의적으로 낮았다. 혈청내 중성지질의 함량은 식이에 따른 유의적 인 차이는 보이지 않았으나 혈청 총콜레스테롤 함량은 대조군에서 101.6 mg/dL, 식이군에서는 73.8∼78.4 mgidL로 유의적으로 낮았으며, 혈청 HDL-콜레스테롤 함량은 모든 실험군에서 39.8∼44.7 mg/dL 범위로 비슷한 수치를 나타내었다. HTR과 동맥경화지수는 대조군에서는 각각 0.44 및 1.27로 나타났으나 헤미셀룰로즈 식이군에서는 각각 0.54 및 0.46∼0.85로 대조군보다 낮았다. 이상의 결과, 콩 식이섬유로부터 추출한 헤미셀룰로즈는 항당뇨효과가 높음을 나타내었다.

• 한국콘텐츠학회논문지
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• 제19권11호
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• pp.375-382
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• 2019

임신 초기 염증으로 인한 영양막세포의 기능 이상은 C-reactive protein (CRP)의 발현을 증가시켜 산모와 태아의 상호작용에 영향을 미침으로써, 조산 및 자간전증 등을 유발한다. 그러나, CRP 발현 조절과 관련된 생체표지자 발굴 및 개발은 미흡한 실정이다. 본 연구는 염증이 유발된 영양막세포에서 증가된 CRP 발현과 관련된 miRNA를 발굴 및 그 발현을 분석함으로써, miRNA를 통해 영양막세포 염증 조절 기전에 관여하는 생체표지자를 밝히고자 한다. miRNA 데이터베이스(mirna, TargetScan, MicroCosm)에서 공통적으로 CRP 유전자 발현을 조절할 것으로 예측되는 miR-7, miR-150, miR-186, 그리고 miR-424를 선별하여 HTR-8/SVneo에 LPS (20ng/mL)를 처리하여 in vitro 상에서 염증 반응을 유도하였다. 각각의 miRNAs의 발현을 qRT-PCR 방법으로 비교 분석하였다. 그 결과, LPS 처리된 영양막세포에서 CRP의 발현은 유의성 있게 증가되었다(p<0.001). miR-150와 miR-424는 발현이 유의성 있게 감소됨을 확인하였다(p<0.001). 따라서, 염증이 유도된 영양막세포에서의 CRP 발현을 조절하는 기전에 miR-150와 miR-424가 관여하는 것을 의미하며, 향후 염증성 산과질환의 산전 진단에 유용한 자료로 사용될 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제22권6호
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• pp.893-899
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• 2009

Few studies have reported the existence of imprinted genes in cattle compared to the human and mouse. Genomic imprinting is expressed in monoallelic form and it depends on a single parent-specific form of the allele. Comparative analysis of mammals other than the human is a valuable tool for explaining the genomic basis of imprinted genes. In this study, we investigated 34 common imprinted genes in the human and mouse as well as 35 known non-imprinted genes in the human. We found short interspersed nuclear elements (SINEs), long interspersed nuclear elements (LINEs), and long terminal repeats (LTRs) in imprinted (human and mouse) and control (cattle) genes. Pair-wise comparisons for the three species were conducted using SINEs, LINEs, and LTRs. We also calculated 95% confidence intervals of frequencies of repetitive sequences for the three species. As a result, most genes had a similar interval between species. We found 11 genes with conserved SINEs, LINEs, and LTRs in the human, mouse, and cattle. In conclusion, eleven genes (CALCR, Grb10, HTR2A, KCNK9, Kcnq1, MEST, OSBPL5, PPP1R9A, Sgce, SLC22A18, and UBE3A) were identified as candidate imprinted genes in cattle.

• 한국응용과학기술학회지
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• 제25권1호
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• pp.73-82
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• 2008

This study was done to investigate the antidiabetic and antioxidant effects of Lycii fructus in Streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by intravenous injection of STZ at a dose 45mg/kg.b.w. dissolved in citrate buffer(pH4.5). The ethanol extract of Lycii fructus was orally administrated once a day for 7 days. The contents of serum glucose, total cholesterol were significantly decreaed (p<0.05) in Lycii fructus treated group compared to the those of STZ-control group, also content of Triglyceride (TG), Altherogenic index (AI) were decreased, but not statistically significant. But high density lipoprotein (HDL)-cholesterol and HDL-cholesterol/total cholesterol ratio (HTR) were increased in Lycii fructus treated group compared to the those of STZ-control group. The content of hepatic glycogen and activities of glucose-6-phosphate dehydrogenase(G-6PDH), glutathione-s-transferase(GST), superoxide dismutase(SOD) were significantly increased(p<0.05), glucose-6-phos-phatase(G-6pase)was significantly decreased(p<0.05) and The glutathione(GSH), glucokinase(GK) were increased. But not statistically significant In Lycii fructus treated group compared to the those of STZ-control group These results indicated that ethanol extract of Lycii fructus would have antidiabetic and antioxidant effects in STZ-induced diabetic rats.

• 한국응용과학기술학회지
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• 제22권2호
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• pp.157-167
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• 2005

The extraction yield of Corni fructus was about 47.5% by extract apparatus. This study was done to investigate the antidiabetic and antioxidative effects of Corni fructus in Streptozotocin (STZ)-induced diabetic rats. The contents of serum glucose, total cholesterol and hepatic lipid peroxide, glutathione were significantly decreaed (p<0.05) in Corni fructus treated group compared to the those of STZ-control group, also content of triglyceride (TG), atherogenic index (AI) and activity of catalase were decreased, but not statistically significant. High density lipoprotein (HDL)-cholesterol and HDL-cholesterol/total cholesterol ratio (HTR) were increased in Corni fructus treated group compared to the those of STZ-control group. The activities of glutathione-S-transferase (GST) and superoxide dismutase (SOD) were significantly decreaed (p<0.05) in Corni fructus treated group compared to the those of STZ-control group. The content of hepatic glycogen and activities of glucose-phosphate dehydrogenase (G-6 PDH), glucokin-ase were significantly increased, but activity of glucose-Grphosphatase (G-6 Pase)was decreased in Corni fructus treated group compared to the those of STZ-control group. Therefore, these results indicated that ethanol extract of Corni fructus would have antidiabetic and antioxidative effects in STZ-induced diabetic rats.

• 한국응용과학기술학회지
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• 제21권3호
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• pp.204-213
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• 2004

Extraction of Sedum sarmentosum Bunge by super critical carbon dioxide was operated under $40-50^{\circ}C$and 200-250 atm, thus, yield of extraction was very low as 4 wt%. Rats were administrated with the extract orally once a day for succesive 6 days, followed by treatment with carbon tetrachloride ($CCl_4$) on the sixth day. The activities of aminotransferase, alkaline phosphatase, ${\gamma}$-glutamyl transpeptidase, lactate dehydrogenase and contents of triglyceride, total cholesterol in the extract-pretreated rats were decreased compared to the $CCl_4$controled rats, whereas content of HDL-cholesterol was increased. Especially content of hepatic malondialdehyde (MDA) and atherogenic index (AI) were decreased and HTR was increased in the extract-pretreated rats, and reduced peroxidative liver damage in the $CCl_4$-induced hepatotoxicity rats. In addition, activities of hepatic superoxide dismutase, catalase, glutathione peroxidase in the extract-pretreated rats were significantly decreased compared to the $CCl_4$ controled rats, but the content of glutathione was significantly increased. These results suggest that extract of Sedum sarmentosum Bunge has hepatoprotective effect in the $CCl_4$-intoxicated rats.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.357-373
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• 2022

The high-temperature gas-cooled reactor pebble-bed module project is the first commercial Generation-IV NPP(Nuclear Power Plant) in China. A new joint is used for the vertical support of RPV(Reactor Pressure Vessel). The steel corbel is integrally embedded into the reactor-cabin wall through eight asymmetrically arranged pre-stressed high-strength bolts, achieving the different path transmission of shear force and moment. The vertical monotonic loading test of two specimens is conducted. The results show that the failure mode of the joint is bolt fracture. There is no prominent yield stage in the whole loading process. The stress of bolts is linearly distributed along the height of corbel at initial loading. As the load increases, the height of neutral axis of bolts gradually decreases. The upper and lower edges of the wall opening contact the corbel plate to restrict the rotation of the corbel. During the loading, the pre-stress of some bolts decreases. The increase of the pre-stress strength ratio of bolts has no noticeable effect on the structure stiffness, but it reduces the ultimate bearing capacity of the joint. A simplified calculation model for the elastic stage of the joint is established, and the estimation results are in good agreement with the experimental results.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.2840-2851
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• 2022

Electric boilers (EBs) are the backup steam source for the auxiliary steam system of high-temperature gas-cooled reactor nuclear power plants. When the plant is in normal operations, the EB is always in hot standby status. However, the current hot standby operation strategy has problems of slow response, high power consumption, and long operation time. To solve these problems, this study focuses on the optimization of hot standby operations for the EB system. First, mathematical models of an electrode immersion EB and its accompanying deaerator were established. Then, a control simulation platform of the EB system was developed in MATLAB/Simulink implementing the established mathematical models and corresponding control systems. Finally, two optimization strategies for the EB hot standby operation were proposed, followed by dynamic simulations of the EB system transient from hot standby to normal operations. The results indicate that the proposed optimization strategies can significantly speed up the transient response of the EB system from hot standby to normal operations and reduce the power consumption in hot standby operations, improving the dynamic performance and economy of the system.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.933-940
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• 2024

A macroscopic cross section generation model was developed for the conceptual horizontal, compact high temperature gas reactor (HC-HTGR). Because there are many sources of spectral effects in the design and analysis of the core, conventional LWR methods have limitations for accurate simulation of the HC-HTGR using a neutron diffusion core neutronics simulator. Several super-cell model configurations were investigated to consider the spectral effect of neighboring cells. A new history variable was introduced for the existing library format to more accurately account for the history effect from neighboring nodes and reactivity control drums. The macroscopic cross section library was validated through comparison with cross sections generated using full core Monte Carlo models and single cell cross section for both 3D core steady-state problems and 2D and 3D depletion problems. Core calculations were then performed with the AGREE HTR neutronics and thermal-fluid core simulator using super-cell cross sections. With the new history variable, the super-cell cross sections were in good agreement with the full core cross sections even for problems with significant spectrum change during fuel shuffling and depletion.