Evaluation of a Dual-Cooled Annular Fuel Heat Split and Temperature Distribution

YANG, Yong Sik,SHIN, Chang Hwan,CHUN, Tae Hyun,SONG, Kun Woo Atomic Energy Society of Japan 2009 Journal of nuclear science and technology Vol.46 No.8

<P>The heat flux and fuel temperature of an annular fuel rod was analyzed using a newly developed program, DUO_THERM. The dual-cooled annular fuel rod has both inner and outer coolant channels. The heat fluxes to inner and outer claddings can change during irradiation because of the variation in the gap conductances of the inner and outer sides. The heat flux is a very important design factor affecting fuel integrity and safety. However, in an annular fuel design, the prediction of heat flux is very complicated because it is closely connected with size changes of two gaps, which are different from each other during irradiation. A burnup increase and power change can cause pellet and cladding radial deformation and eventually change the gap width. Because an annular fuel has two gaps at both sides and their heat resistances are very large, an imbalance of the gap width can lead to heat flux asymmetry. Therefore, a pellet and cladding dimensional change including densification, swelling, creep, and thermal expansion must be considered in the calculation of heat flux and temperature. By using the DUO_THERM program, the changes in heat flux and temperature during an operation were evaluated with respect to a reference design of an annular fuel. The results of the evaluation showed that the heat flux of an annular fuel was greatly affected by the inner and outer gap conductance changes. The heat flux of the inner cladding was maximum at zero burnup, but that of the outer cladding was maximum at the burnup of the outer gap closing. In addition, the maximum fuel temperature location was changed by gap conductance asymmetry.</P>

건축 프로젝트 적정 설계변경 관리를 위한 사례조사

김성욱(Kim Sung-Wook),남혜원(Nam Hye-Won),이종식(Lee Jong-Sik),신창현(Shin Chang-Hyun),전재열(Chun Jae-Youl) 대한건축학회 2009 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.29 No.1(구조계)

Recent design changes in the existing research on the factors and issues of design changes and analysis, responsible for analyzing the relationship, procedural issues, and issues of research that can be active. However, changes in the design of problems are essentially designed to complement the book is for the procedure. Methodology for dealing with design changes in the characteristics of the country and to reflect more realistically, and various design changes and looked at trends in related research. the design Change of this study to examine the domestic status and problems, identify the status of the country about the design changes, and in suggesting the direction to the development of the design changes.

Rat의 복강내에 투여한 5-fluorouracil-polyglycolic acid 제형이 장기에 미치는 영향에 관한 연구

강대영,송규상,최정목,노승무,정경수,오정연,김진향,양준묵,최선웅,이진호,조준식,민병무,김용백,김창식,박근성,김승영,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

For more effective intraperitoneal chemotherapy, the authers made 5-fluorouracil-polyglycolic acid composite disks(FU-PGA disks) with 5-fluorouracil and polyglycolic acid, a biodegradable polymer. We inserted the FU-PGA disk into the peritoneal cavites of Sprague-Dawley male rats, the control and three experimental groups; one FU-PGA disk insert group(300mg/kg), two FU-PGA disk insert group(600mg/kg), and three FU-PGA disk insert group(900mg/kg). The control group received a similar number of PGA disk inserts. A pharmacokinetic study was performed to measure the 5-fluorouracil concentration in the peritoneal fluid, blood, and tissues(liver, kidney and heart) at 24 hours, 72hours and 168 hours after insertion of the FU-PGA disk. Light and electron microscopic studies were done. The results were as follows: 1) The number of white blood cells and platelets decreased after FU-PGA insertion. The degree was proportional to the duration and amounts inserted. The change in the number of red blood cells varied slightly. 2) Light microscopically, slight changes were noted at 168 hours in the 3 disk insert group (900mg/kg). Mild fatty change and hepatocyte degeneration around the central veins of the liver were noted, with vacuolar degeneration in the proximal convoluted tubules of the kidney. 3) Electron microscopically,the liver showed focal increases of lipid droplets in the hepatocytes, and irregular nuclear membrane with focal nucleolar segregation of the fibrillar and granular elements. Also the double membranous structure of the hepatocytes and Kupffer cells was widened with bleb formation. The kidney showed wide separation of the nuclear double membrane in the proximal convoluted tubular cells and mesangial cells, with vacuolation and myelin figure formation in the mitochondria of the proximal convoluted tubular cells, at 72 hours and 168 hours in the 2 to 3 FU-PGA insert groups. The heart showed focal loss of cristae,vacuolation and myelin figure formation in the mitochondria of the 2 to 3 FU-PGA insert groups. In conclusion, despite the large amont of FU-PGA inserted, the histopathological changes in the liver, kidney and heart were slight, and consonant with the very low amount of 5-fluorouracil concentrations detected in the liver, kidney and heart. The above results suggest that the FU-PGA composite can serve as a new device for releasing drugs in a controlled manner and easily targeted to intraperitoneal organs. This device can improve the efficacy of intraperitoneal chemotherapy for gastric cancer.

암세포 증식에 대한 YB-1 안티센스 올리고핵산염의 영향

김명성 ( Myung Sung Kim ),이완식 ( Wan Sik Lee ),박창환 ( Chang Hwan Park ),주영은 ( Young Eun Joo ),김현수 ( Hyun Soo Kim ),최성규 ( Sung Kyu Choi ),유종선 ( Jong Sun Rew ),정영도 ( Young Do Jung ),김세종 ( Sei Jong Kim ),안봉환 대한내과학회 2006 대한내과학회지 Vol.71 No.3

목적: YB-1은 PCNA, DNA 중합효소 및 MDR 유전자 등의 전사인자로 작용한다. YB-1 유전자는 정상 어른의 간에서는 발현되지 않지만 태아의 간이나 재생 중인 간에서는 발현이 현저히 증가되어서 세포의 증식과 밀접한 관련이 있음이 보고되었다. 본 연구에서는 YB-1 유전자의 안티센스 올리고핵산염을 이용하여 YB-1의 발현을 억제함으로써 암세포 증식을 차단 할 수 있는지를 실험하고 암치료를 위한 유전자 요법으로서의 가능성을 알아보았다. 방법: 세포주로는 Chang liver, HepG2, CT-26 세포를 사용하였고, 사람의 정상세포로는 섬유아세포와 내피세포가 혼재된 조직을 사용하였다. YB-1 유전자의 안티센스 올리고핵산염으로는 YB-1 cDNA의 변역 시작 부위에 상보적인 21mer 올리고핵산염을 제작하여 사용하였다. 세포의 성장은 MTT assay를 이용하였고, 유전자 발현은 Northern blot으로 분석하였으며, 세포주기 변화는 propidium iodide로 염색하여 유식세포분석기로 분석하였다. 동물실험에서는 CT-26 세포를 1.0×10(5)개씩 Balb/c 생쥐의 피하에 접종하여 종양을 유도하였다. 종양이 유도된 Balb/c 생쥐에 YB-1 안티센스 올리고핵산염을 꼬리정맥이나 종양조직에 주사한 후 종양의 크기를 측정하여 종양억제 효과를 관찰하였다. 결과: YB-1 안티센스 올리고핵산염은 CT-26 세포에서는 50 nM 이상 농도에서 Chang liver와 HepG2 세포에서는 10 nM 이상 농도에서 세포주의 성장을 강하게 억제하였지만 정상 조직세포의 성장에는 아무런 영향을 미치지 않았다. 안티센스 올리고핵산염을 DOTAP에 담지한 경우 세포성장 억제에 미치는 효과가 안티센스 올리고핵산염 단독 처치 보다 강하였다. 이때 YB-1의 발현은 증식이 억제된 세포주(Chang liver 및 CT-26)에서는 감소하였으나 정상조직세포에서는 변화가 없었다. 증식이 억제된 세포주에서 세포주기를 살펴보면 초기에 S phase가 감소함을 관찰 할 수 있었다. 꼬리정맥이나 종양조직에 YB-1 안티센스 올리고핵산염을 주입 시 종양의 크기가 유의하게 감소하였다. 결론: 이상의 실험 결과 YB-1 안티센스 올리고핵산염은 암세포의 성장을 저해하며 종양 동물모델에서 종양의 성장을 억제할 수 있음을 시사하였다. Background: Human YB-1 is a transcription factor that binds to the inverted CCAAT box in the promoter region of a variety of genes such as PCNA, DNA polymerase and MDR. In this study we evaluated the effect of YB-1 antisense oligonucleotides on tumor cell growth. Methods: Chang liver, HepG2 and CT-26 cells were cultured as immortalized cell lines. The MTT (3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyltetrazolium bromide) assay, Northern blot and flow cytometric analyses were used to determine cell growth, gene expression and cell cycle changes. In an animal model, CT-26 cells were injected into Balb/c mice to induce tumor; YB-1 antisense oligonucleotides were injected into the tail vein or tumor tissue of the mice; change of tumor size was then measured. Results: Phosphorothioated YB-1 antisense oligonucleotides suppressed the proliferation of the immortalized liver cells (Chang liver cells) and a variety of cancer cells (HepG2 and CT-26 cells); however, it did not inhibit normal cell growth. The DOTAP/antisense oligonucleotide mixture showed stronger effects on cell proliferation than did the antisense oligonucleotide alone. The YB-1 antisense oligonucleotide decreased specific expression of the YB-1 mRNA in the immortalized cancer cell lines. Flow cytometric analysis revealed that the inhibition of cell proliferation might have been due to a decrease in the S phase of the cell cycle. We found that in an animal tumor model, the administration of the YB-1 antisense oligonucleotide, in the vein or tumor tissues, decreased the tumor size significantly. Conclusions: These results suggest that the YB-1 antisense oligonucleotide may inhibit growth of a variety of cancer cells.(Korean J Med 71:293-301, 2006)

Biomechanical analysis of lumbar decompression surgery in relation to degenerative changes in the lumbar spine – Validated finite element analysis

Li, Quan You,Kim, Ho-Joong,Son, Juhyun,Kang, Kyoung-Tak,Chang, Bong-Soon,Lee, Choon-Ki,Seok, Hyun Sik,Yeom, Jin S. Elsevier 2017 Computers in biology and medicine Vol.89 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>There are no studies about the biomechanical analysis of lumbar decompression surgery in relation to degenerative changes of the lumbar spine. Therefore, the purpose of this study was to compare, by using finite element (FE) analysis, the biomechanical changes of the lumbar spine in terms of annulus stress and nucleus pressure after two different kinds of lumbar decompression surgery in relation to disc degenerative changes.</P> <P><B>Methods</B></P> <P>The validated intact and degenerated FE models (L2-5) were used in this study. In these two models, two different decompression surgical scenarios at L3-4, including conventional laminectomy (ConLa) and the spinous process osteotomy (SpinO), were simulated. Therefore, a total of six models were simulated. Under preloading, 7.5 Nm moments of flexion, extension, lateral bending, and torsion were imposed. In each model, the maximal von Mises stress on the annulus fibrosus and nucleus pressure at the index segment (L3-4) and adjacent segments (L2-3 and L4-5) were analyzed.</P> <P><B>Results</B></P> <P>The ConLa model and disc degeneration model demonstrated a larger annulus stress at the decompression level (L3-4) under all four moments than were seen in the SpinO model and healthy disc model, respectively. Therefore, the ConLa model with moderate disc degeneration showed the highest annulus stress at the decompression level (L3-4). However, the percent change of annulus stress at L3-4 from the intact model to the matched decompression model was less in the moderate disc degeneration model than in the healthy disc model.</P> <P><B>Conclusions</B></P> <P>Although the ConLa model with moderate disc degeneration showed the highest annulus stress, the degenerative models would be less influenced by the decompression technique.</P>

A New MPEG-2 Rate Control Scheme Using Scene Change Detection

Park, Sang-Gyu,Lee, Young-Sun,Chang, Hyun-Sik Electronics and Telecommunications Research Instit 1996 ETRI Journal Vol.18 No.2

We propose two new rate control schemes to improve MPEG-2 rate control in view of visual quality when scene changes happen. Two proposed schemes are characterized by real-time and non real-time improvement to reduce the impact of scene changes. We also propose a new target-bit prediction method using spatial activity of pictures and present a simple and efficient scene change detection scheme using signed difference of mean absolute difference (MAD). Computer simulation results show that the proposed real-time algorithm effectively alleviates visual quality degradation after scene changes. The proposed non real-time algorithm gives maximum 2 dB improvement in peak signal-to-noise ratio (PSNR) at a scene-changed picture, compared with MPEG-2 rate control scheme and it shows better quality than the real-time one.

Effect of Extreme Heatwaves on the Mortality and Cellular Immune Responses of Purplish Bifurcate Mussel Mytilisepta virgata (Wiegmann, 1837) (=Septifer virgatus) in Indoor Mesocosm Experiments

Hyun-Ki Hong,Chang Wan Kim,Jeong-Hwa Kim,Nobuhisa Kajino,Kwang-Sik Choi 제주대학교 해양과학연구소 2021 해양과환경연구소 연구논문집 Vol.45 No.-

In the rocky intertidal environment, the frequency and duration of heatwaves have increased over the last decade, possibly due to global climate change. Heatwaves often result in lethal or sub-lethal disturbances in benthic animals by changing their metabolic activities. In this study, we investigated the impacts of extreme heatwave stress on the hemocyte functions of Mytilisepta virgata and subsequent mortality to gain a better understanding of the potential causes and consequences of mass mortality events in this mussel during summer. We discriminated three types of hemocytes in the hemolymph, granulocytes, hyalinocytes, and blast-like cells, using flow cytometry and revealed that granulocytes were the major hemocyte involved in cellular defensive activities, such as phagocytosis and reactive oxygen species (ROS) production. For the experiment, mussels were exposed to a 40◦C air temperature for 12 h per day over 5 days under laboratory conditions as a simulated semi-diurnal tidal cycle. Mortality began to occur within 3 days after beginning the experiment, and all mussels had died by the end of the experiment. Flow cytometry indicated that the mussels exposed to high air temperatures produced significantly more ROS than did the control mussels within 2 days after the onset of the experiment, which may have caused oxidative stress. Such high levels of ROS in the hemolymph increased DNA damage in hemocytes after 3 days of exposure and decreased the phagocytosis of hemocytes 4 days after the experiment began. The observed mortality and decline in immune capacity suggested that an extreme heat event occurring in the rocky intertidal ecosystem during summer could exert sublethal to lethal impacts on macrobenthic animals.

The counseling protocol according to psychological change to successful return to sports after anterior cruciate ligament reconstruction

Se-Hyun Park,Chang-Sik Um,Eun-Surk Yi 한국운동재활학회 2019 한국운동재활학회 학술대회 Vol.2019 No.05

Anterior cruciate ligament (ACL) injuries are one of the most common sports injury. There are many studies on various methods of rehabilitation exercise after surgery and mostly has been done on rehabilitation exercise programs tailored to physical changes according to each stage. However, there is little studies on the psychological counseling protocol according to stage of psychological change. The purpose of this study was to research the method of counseling according to psychological change in the patient after anterior cruciate ligament reconstruction (ACLR). The subject of this study were 60patients who underwent ACL surgery at department of orthopedic surgery, Guro hospital, Korea university. This study evaluated the emotion, confidence and risk of re-injury of patients by using ACL-RSI (ACL-Return to Sport after Injury)questionnaire. The study of result was investigate that a significant difference in all three domains in the group that could return to myself in comparison to the group who did not return to themselves(p<.05). The results of this study suggested that psychological stability was importance for a successful return after 6months, which is the time of returning from ACL surgery. Through these results, this study examined the psychological counseling methods for each recovery stage after ACL reconstruction. Also this study proposed that the psychological counseling methods by summarizing the views of various experts. The proposed contents are as follows. Phase 1, the psychological state of patients was anxiety, emotional state was fear, maladjustment and depression. Exports’s keyword of counseling method was rehabilitation cognition, effort, hope, recovery, hope. Phase 2, the psychological state of patients was slump, emotional state was maladjustment, patience and acception. Exports’s keyword of counseling method was encouragement, counsel, goal setting, effort, challenge, current representation. Phase 3, the psychological state of patients was Adaptation of physical function, emotional state was challenge, patience and acception. Exports’s keyword of counseling method was goal setting, vision, desire, effort, encouragement, counsel. Phase 4, the psychological state of patients was adaptation of Activity Daily Living(ADL), emotional state was patience, compromise and challenge. Exports’s keyword of counseling method was current situation cognition, caution recommendation, plan, vision, goal setting, effort. Phase 5, the psychological state of patients was stability, emotional state was challenge, acception and patience. Exports’s keyword of counseling method was return, counsel, solution, communication, caution recommendation, encouragement, patience.

Age-Associated Changes in the Vascular Renin-Angiotensin System in Mice

Yoon, Hye Eun,Kim, Eun Nim,Kim, Min Young,Lim, Ji Hee,Jang, In-Ae,Ban, Tae Hyun,Shin, Seok Joon,Park, Cheol Whee,Chang, Yoon Sik,Choi, Bum Soon Hindawi Publishing Corporation 2016 Oxidative medicine and cellular longevity Vol.2016 No.-

<P><I>Background</I>. This study evaluated whether the change in the renin-angiotensin system (RAS) is associated with arterial aging in mice.<I> Methods</I>. Histologic changes and expressions of transforming growth factor-<I>β</I> (TGF-<I>β</I>), collagen IV,<I> fibronectin</I>, angiotensin II (Ang II), angiotensin-converting enzyme (ACE), angiotensin-converting enzyme 2 (ACE2), angiotensin II type 1 receptor (AT1R), angiotensin II type 2 receptor (AT2R), prorenin receptor (PRR), Mas receptor (MasR), endothelial nitric oxide synthase (eNOS), NADPH oxidase 2 and oxidase 4 (Nox2 and Nox4), 8-hydroxy-2′-deoxyguanosine (8-OHdG),<I> 3-nitrotyrosine</I>, and superoxide dismutase 1 and dismutase 2 (SOD1 and SOD2) were measured in the thoracic aortas from 2-month-old, 12-month-old, and 24-month-old C57/BL6 mice.<I> Results</I>. Twenty-four-month-old mice showed significantly increased aortic media thickness and expressions of TGF-<I>β</I>, collagen IV, and fibronectin, compared to 2-month-old and 12-month-old mice. The expressions of PRR, ACE, and Ang II, and AT1R-positive area significantly increased, whereas expressions of ACE2 and MasR and AT2R-positive area decreased with age. The expressions of phosphorylated serine<SUP>1177</SUP>-eNOS, SOD1, and SOD2 decreased, and the 8-OHdG-positive area and the 3-nitrotyrosine-positive area increased with age. The expression of Nox2 significantly increased with age, but that of Nox4 did not change.<I> Conclusions</I>. The enhanced PRR-ACE-Ang II-AT1R axis and reduced ACE2-MasR axis were associated with arterial aging in mice. </P>

Endoscopy and Imaging Modalities/Basic Science of Gastrointestinal Disorders/Miscellaneous : Changing Pattern Of Digestive And Liver Disease In Korea, 1990-2006 Year; A Single Center Study

( Jung Hyun Kwon ),( Sang Woo Kim ),( In Sik Chung ),( Myung Gyu Choi ),( Kwan Woo Nam ),( Jung Pil Suh ),( Jae Hyuck Chang ),( Won Haing Hur ),( Yu Kyung Cho ),( Jae Myung Park ),( In Seok Lee ) 대한소화기학회 2007 SIDDS Vol.9 No.-

Background/Aims: Westernization in many Asian countries have changed lifestyles and diets, so once rare diseases have now become prevalent. The aim of this study is to investigate the changing pattern of digestive and liver disease in Korea, from 1990 to 2006. Methods: We extracted data specific gastrointestina (GI) disease based on the International Classification of Diseases code from the in-patients records at the Kangnam St. Mary`s Hospital in 1990, 1996 and 2006. This hospital is a tertiary-care hospital in Seoul, Korea, which has a capacity of 800 beds. Results: The admission rate for GI disease increased between 1990 and 2006. Overall in-patients were 1,623 persons in 1990, 2,368 persons in 1996 and 4,166 persons in 2006. The mean age of in-patients increased as time went by. A stomach cancer was the most common diagnosis during all periods, but its prevalence has decreased. Colon cancer ranked the 7th in 1990, but markedly increased and now ranks the second. The third was a hepatocellular carcinoma. The bile duct and gallbladder cancer, pancreas and esophageal cancer ranking followed with little interval change. In cases of cancer patients, a regular admission dramatically increased for chemotherapy. The number of patients admitted with pre-malignant neoplasm of stomach and colon increased remarkably with the development of endoscopy. The liver transplant, inflammatory bowel discase, and reflux esophagitis emerged form mid-1990s with greater frequencies, yet much below the levels found in the West. The admission rate for peptic ulcer, especially ulcer bleeding remained relatively stable, despite a decreased rate for ulcer perforation. Liver cirrhosis, hepatitis, cholelithiasis with cholecystitis-cholangitis, appendicitis, hemorrhoid and gastritis all decreased. Conclusions: The stomach cancer is the leading cause of admission, despite a recent decline. Colon cancer showed a marked rise. The liver transplant, inflammatory bowel disease and reflux esophagitis were new diagnosis with an increased tendency.