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      • Comparison of trophic factors changes in the hippocampal CA1 region between the young and adult gerbil induced by transient cerebral ischemia.

        Yan, Bing Chun,Park, Joon Ha,Kim, Sung Koo,Choi, Jung Hoon,Lee, Choong Hyun,Yoo, Ki-Yeon,Kwon, Young-Geun,Kim, Young-Myeong,Kim, Jong-Dai,Won, Moo-Ho Kluwer Academic/Plenum Publishers 2012 Cellular and molecular neurobiology Vol.32 No.8

        <P>In the present study, we investigated neuronal death/damage in the gerbil hippocampal CA1 region (CA1) and compared changes in some trophic factors, such as brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial growth factor (VEGF), in the CA1 between the adult and young gerbils after 5 min of transient cerebral ischemia. Most of pyramidal neurons (89%) were damaged 4 days after ischemia-reperfusion (I-R) in the adult; however, in the young, about 59% of pyramidal neurons were damaged 7 days after I-R. The immunoreactivity and levels of BDNF and VEGF, not GDNF, in the CA1 of the normal young were lower than those in the normal adult. Four days after I-R in the adult group, the immunoreactivity and levels of BDNF and VEGF were distinctively decreased, and the immunoreactivity and level of GDNF were increased. However, in the young group, all of their immunoreactivities and levels were much higher than those in the normal young group. From 7 days after I-R, all the immunoreactivities and levels were apparently decreased compared to those of the normal adult and young. In brief, we confirmed our recent finding: more delayed and less neuronal death occurred in the young following I-R, and we newly found that the immunoreactivities of trophic factors, such as BDNF, GDNF, and VEGF, in the stratum pyramidale of the CA1 in the young gerbil were much higher than those in the adult gerbil 4 days after transient cerebral ischemia.</P>

      • 노화가 인체 중간엽 줄기세포로부터 조골세포로의 증식 및 분화에 미치는 영향

        백기현,태현정,오기원,이원영,조정기,권순용,강무일,차봉연,이광우,손호영,강성구,김춘추 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.3

        연구배경: 일반적으로 골다공증과 연관된 위험인자로는 연령, 폐경, 약물, 불충분한 칼슘섭취, 만성질환 및 운동부족 등이 있는데, 특히 노화가 진행할수록 골밀도가 감소하는 것은 잘 알려져 있다. 노화와 관련하여 진행되는 골소실은 조골세포 및 전구조골세포의 기능적 결핍에 의한 골형성의 감소가 주요한 요인으로 여겨지고 있다. 그 동안 연령이 조골모 세포의 양과 조골모 세포로부터 성숙조골세포로의 분화 및 증식에 미치는 영향에 대한 일부 보고들이 있었으나 아직 일치된 견해는 없는 형편이다. 방법: 다양한 연령의 사람으로부터 골수를 채취, 중간엽 줄기세포가 포함된 단핵세포를 분리한 후 조골세포로 분화하기 좋은 조건하에서 배양하였다. 대상군은다시 젊은군과 노령군으로 구분하여 다양한 변수를 비교 분석하였다. 일차배양에서는 CFU-F를 계수하여 골수내 중간엽 줄기세포의 수를 추산하였고, 칼슘측정을 통하여 기질의 무기화 정도를 비교하였다. 계대배양후 이차배양에서는 시기별로 알카리성 포스파타제 활성도를 측정하고 오스테오칼신 mRNA의 발현을 관찰하여 젊은군과 노령군 사이의 증식능 차이를 비교하였다. 또한 이차배양 시기별로 MTT 측정을 하여 양군간에 증식능 차이가 있는지 알아보았다. 결과: 1. 일차배양 15일째에 평균 CFU-F의 수는 젊은군에서 유의하게 많았다(젊은군 148.3±28.9, 노령군 54.3±9.1, p=0.02). CFU-F의 평균면적은 젊은군에서 넓은 경향을 보였으나 통계적으로 유의하지는 않았다. 2. 일차배양 17일 경과 후 양군간에 기질 칼슘 침착정도는 유의한 차이를 보이지 않았다(젊은군 103.6±50.6, 노령군: 114.0±56.5, p=NS). 3. 이차배양 10일째에 젊은군에서 알카리성 포스파타제 활성도가 고령군에 비해 유의하게 높았다(젊은군: 935.5±115.0 U/mg, 노령군: 578.4±115.7U/mg,p.0.05). 고령군에서는 시간 경과에 따른 변화가 미약했으며 전반적으로 알카리성 포스파타제의 활성도가 젊은군에 비해 낮았다. 4. 이차배양도중 오스테오칼신 mRNA의 발현은 배양시기별로 젊은군에 비해 고령군에서 더 낮은 경향을 관찰할 수 있었다. 5. 이차배양 10일과 15일에 젊은군에서 노령군보다세포증식이 유의하게 증가된 양상을 보였다(10앓 젊은군 0.73±0.05, 노령군 0.58±0.04, p=0.05, 15일; 젊은군 0.80±0.05, 노령군 0.70±0.03, p=0.05).결론: 이상의 연구에서 저자들은 노령군에서 젊은군보다 골수 내 중간엽줄기세포의 수가 적고, 노령군에서 유래한 전구조골세포의 성숙조골세포로의 증식 및 분화가 젊은군 보다 감소해 있는 것을 관찰할 수 있었다. Background: Osteoblasts originate from osteoprogenitor cells in bone marrow stroma, termed mesenchymal stem cells (MSCs) or bone marrow stromal cells. Each MSC forms colonies (colony forming units-fibroblasts [CFL-Fs]) when cultured ex vivo. There are some reports about the age-related changes of the number and osteogenic potential of osteoprogenitor cells, but any relationship has not been clearly established in humans. In this study, we counted MSCs using CFU-Fs count and examined the proliferative capacity and differentiation potential of osteoprogenitor cells. Finally, we analyzed how these parameters varied with donor age. Methods: Bone marrow was obtained from the iliac crest of young (n=6, 27.2±8.6 years old) and old (n= 10, 57.4k6.7 years old) healthy donors. Mononuclear cells, including MSCs, were isolated and cultured in osteogenic medium. In primary culture, we compared the colony-forming efficiency of MSCs between the two groups and determined the matrix calcification. When primary culture showed near confluence, the cells were subcultured. Alkaline phosphatase activity, osteocalcin expression by RT-PCR and proliferative potential by MTT assay were examined by the time course of secondary culture. Results: At the 15th day of primary culture, the mean number of CFU-Fs was significantly higher in the younger donors (young: 148.3±28.9, old: 54.3±9.1, p=0.02) and the mean size of CFL-Fs was also larger in the younger donors than the older donors. However, matrix calcification was not different between the two groups (young: 103.6±50.6, old: 114.0±56.5, p=NS). In secondary culture, alkaline phosphatase activities were significantly lower in the older donors. The younger donors showed peak alkaline phosphatase activity at day 10, while the older donors didn't showed a remarkable peak (young: 935.5±115.OU/mg, old: 578.4±115.7U/mg, p<0.05). Total cell number as a proliferative index increased progressively during the secondary culture and a significantly greater cell number was noted in the younger donors. Osteocalcin expression was generally upregulated in the younger donors, but this was not statistically significant. Conclusion: Our study shows that the number of osteoprogenitor cells is decreased during aging and that the proliferative capacity and differentiation potential of osteoprogenitor cells seem to be reduced during aging (J Kor SOC Endocrinol 18:296-305, 2003).

      • Development of High efficiency Food Waste Treatment System for Entering New and Renewable Energy Industry in Southeast Asia

        Kwon,Ki-Tae,Lee,Woo-Sik,Kwon,Lee-Seung,Seong,Seung-Hwan,Kim,Young-Do,Kwon,Woo-Taeg 한국유통과학회 2019 KODISA ICBE (International Conference on Business Vol.2019 No.-

        It is possible not only to treat high concentration organic matter such as food wastes but also to utilize food wastes as resources according to the bio-energy generation such as methane. The method of co-digestion of mixed wastewater mixed with organic wastes such as sewage sludge concentrated waters together with drinking wastewater is the most ideal method. Radiation not only has germicidal power in water treatment, but also is effective in decomposing degradable organic matter. Second chemical contamination problem is also solved because it does not use chemicals. Introduction of radiation pretreatment system to solve problems caused by mixing of waste water and organic waste resources. Biological electrochemical fusion system is used to remove the nutrients contained in the organic matter-removed mixture. Through the development of a system for treatment of high concentration wastewater, the processing efficiency is verified through the universal water treatment system for wastewater containing high concentration organic matter in addition to treatment of wastewater.

      • KCI등재후보

        Biochemical Characteristics and Antimicrobials Susceptibility of Salmonella gallinarum Isolated in Korea

        Ki-seuk Kim,Young-ju Lee,Yong-kuk Kwon,Ryun-bin Tak 대한수의학회 2003 Journal of Veterinary Science Vol.4 No.2

        Characteristics and Antimicrobials Susceptibility of Salmonella gallinarum Isolated in KoreaYoung-ju Lee, Ki-seuk Kim1,*, Yong-kuk Kwon and Ryun-bin Tak1Avian Disease Division, National Veterinary Research and Quarantine Service, Anyang 430-824, Korea1College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, KoreaReceived February 13, 2003 / Accepted April 30, 2003J. Vet. Sci. (2003), 4(2), 161-166JOURNAL OFVeterinaryScience*Corresponding author: Ki-seuk Kim College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, Korea Tel: 82-53-950-5962, Fax: 82-53-950-5955 E-mail: kimkiseuk@knu.ac.kr

      • SMR 컨버터를 이용한 자연 회생형 소프트 스위칭에 관한 연구

        권순걸,시거영,구헌회 경남대학교 공업기술연구소 2000 硏究論文集 Vol.18 No.-

        전원 장치의 소형화와 전력 변환 효율의 증가를 위하여 고주파 스위칭 기술이 적용되고 있지만 이에 따른 스위칭 손실과 고주파 노이즈 증가의 문제가 발생한다. 이런 고주파 스위칭 손실은 스위칭 소자의 기생 커패시터에 의한 스위칭 턴-온 손실이 주요한 요인이다. 이러한 손실을 줄이기 위하여 소프트 스위칭 방법을 이용한다. 소프트 스위칭 회로는 주회로 전류를 공진시켜 공진파형을 이용하여 출력 파형을 형성하는 공진형과 스위칭 기간만 공진현상을 이용하고 다른 부분은 전압과 전류를 일정한 값에 클램프하는 부분 공진형이 있다. 이에 본 논문에서는 이러한 부분 공진형 회로에서 신뢰성을 향상시키고 회생에너지를 주 스위칭에 이용하여 회생하는 전압 입력형 소프트 스위칭 회로에 관하여 연구하였다. High frequency switching technique is suitable for making power conversion System. However, it causes switching loss and increasing high frequency noise. To improve this problem, resonant circuit is usually used. Especially, partial resonant circuit is well suited for high power demanding. This paper proposes SMR converter circuit, which consists of frequency conversion circuit, isolated transformer, and snubber circuit. Main circuit has center tap in transformer and use it as one line of AC input. Therefore, snubber voltage could be clamped constant voltage and this snubber circuit act as energy recovery. Thus, it has small loss and improves power efficiency.

      • 缺損家庭學生의 體力 및 身體健康狀態에 關한 硏究

        權永玉,李炳璣 忠南大學校體育科學硏究所 1983 體育科學硏究誌 Vol.1 No.1

        This study was performed to obtaine some informations for development of physique and improvement of physical fitness of students who lost their mother or father by measurement of their physique, physical fitness, and somatic health status. For this study, 77 high school girls who lost their mother or father and 97 high school girls who have had their parents (general students) were served as subjects. The results of comparison between two groups is as follow: 1. physical fitness and somatic health status of students who lost their mother or father was very worse than general students. 2. There was no significant difference in comparison of physical fitness and somatic health status accoring to the sex distinction of lost parents, but generally case of mother lost was worse than case of father lost. 3. In comparison of physical fitness and particulary somatic health status according ot the type of loss of parents, the group of loss of parents by divorce was worse than the group of loss of parents by death of parents. 4. In physical fitness, long-term experienced group(for more than ten years) of loss of parents was worse than short-term experienced group(for less than ten years) of loss of parents.

      • 수정진동자에 의한 Langmuir-Blodgett(LB) 누적막의 평가

        권영수,장상목,김기완 경북대학교 센서기술연구소 1991 센서技術學術大會論文集 Vol.2 No.1

        AT-cut quartz crystals and SAW devices were applied as immunosensors and chemical vapour sensors coated with PG, PI, PE, PS and lipid A were useful for determine of amylacetate, acetoin, menthone and other organic vapours, which showed different affinities for each lipid. We conducted that the key problems of our sensor system for practical application are life time and reproducibility from our results. The most important points are chemical instability of natural lipid materials and randomness of coating method. In this paper, we combined an artificial lipid with a piezoelectric crystal in order to improve stability of our sensor. LB technique was applied to produce uniform lipid layers on the crystals. Relationships between frequency change and number of LB layers are also discussed.

      • 염소함유 변성 폴리에스테르 폴리올을 이용한 수분산 난연 폴리우레탄의 제조 및 특성

        권기섭,이영규,우종표 明知大學校 産業技術硏究所 2000 産業技術硏究所論文集 Vol.19 No.-

        Aqueous urethane dispersion resin begins to assume commercial importance due to increasing environmental awareness of VOC in coating industry. Moreover there have been strong industrial needs for the development of reactive-type polyurethane flame retardant coatings. In this study, chlorinated polyester polyols were synthesized by two step polycondensation reaction using various chloroacetic acid, adipic acid, trimethylol propane, and 1,4-butanediol. In the next step polyurethane dispersion was prepared using these chlorinated polyester polyols and isophorone diisocyanate with dimethylol propionic acid(DMPA) and trimethylamine. The structure of chlorinated polyol was characterized by GPC, FT-IR and NMR. Particle size and its distribution were examined in term of various dispersion parameters including molecular weight and composition of polyol, amount of DMPA, and NCO/OH ratio, etc. The effect of chlorinated polyols on flammability and physical properties was also evaluated.

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