• 대한의생명과학회지
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• 제1권1호
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• pp.19-25
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• 1995

소는 인간에게 고기와 우유를 제공하는 영양자원으로서 뿐만 아니라 노동력을 제공하는 중요한 가축 동물 중의 하나이다. 또한 사람의 질병을 규명하고 예방 및 치료의 실험적 도구로서도 많이 이용되고 있으나, 대동물이라는 점과 경제적인 이유로서 일반적인 응용과 실험적 적용에 어려움이 되어왔다. 저자들은 이와 같은 사정을 감안하여 실험적 기초 자료를 얻기 위하여, 한우를 대상으로 말초혈액상과 특히 림프아군의 특성을 알아본 결과 다음과 같이 일부 결과를 얻었다. 즉, 한우 22마리(암컷 12마리, 숫컷 10마리)의 말초혈액을 채혈하여 림프구 표면항원의 특성을 단클론항체와 반응시키고 flow cytometry로 측정한 결과 CD2는 숫컷에서 53%, 암컷에서 54%의 반응을 보였고, CD4는 숫컷에서 30% 암컷에서 32%의 반응을 보였으며, CD8에서는 숫컷에서 13%, 암컷에서 13%의 반응을 보였다. 그리고 말초혈액상은 RBC가 숫컷 7.20$\times10^6{mm}^3$, 암컷 6.35$\times10^6{mm}^3$이었고 WBC는 숫컷 8.09$\times10^3{mm}^3$, 암컷 7.09$\times10^3{mm}^3$었으며 leukocyte differential counts 에서는 lymphocytes, Neutrophils, Eosinophils의 순으로 높은 성적을 보였다.

• The Korean Journal of Physiology and Pharmacology
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• 제2권1호
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• pp.119-131
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• 1998

It has been reported that the glycoprotein extracted from Aloe has strong anti-inflammatory response. However, there has been no research report yet about the effect of Aloe on allergic hypersensitivity reactivity. By using guinea pig lung mast cells, this study aimed to examine the effects of Aloe glycoprotein (NY945) on the mediator releases caused by mast cell activation, and also aimed to assess the effects of NY945 on the mechanism of mediator releases in the mast cell activation. We partially purified mast cell from guinea pig lung tissues by using the enzyme digestion, the rough and the discontinuous density percoll gradient method. Mast cells were sensitized with IgG1 (anti-OA) and challenged with ovalbumin. Histamine was assayed by fluorometric analyzer, leukotrienes by radioimmunoassay. The phospholipase D activity was assessed by the production of labeled phosphatidylalcohol. The amount of mass 1, 2-diacylglycerol (DAG) was measured by the $[^3H]DAG$ produced when prelabeled with $[^3H]myristic$ acid. The phospholipid methylation was assessed by measuring the incorporation of the $[^3H]methyl$ moiety into phospholipids of cellular membranes. Pretreatment of NY945 (10 ${\mu}g$) significantly decreased histamine and leukotrienes releases during mast cell activation. The decrease of histamine release was stronger than that of leukotriene during mast cell activation. The phospholipase D activity increased by the mast cell activation was decreased by the dose-dependent manner in the pretreatment of NY945. The amount of DAG produced by PLC activity was decreased by NY945 pretreatment. The amount of mass 1, 2-diacylglycerol produced by activation of mast cells was decreased in the pretreatment of NY945. NY945 pretreatment strongly inhibited the incorporation of the $[^3H]methyl$ moiety into phospholipids. The data suggest that NY945 purified from Aloe inhibits in part an increase of 1, 2-diacylglycerol which is produced by activating mast cells with antigen-antibody reactions, which is mediated via phosphatidylcholine-phospholipase D and phosphatidylinositol-phospholipase C systems, and then followed by the inhibition of histamine release. Furthermore, NY945 reduces the production of phosphatidylcholine by inhibiting the methyltransferase I and II, which decreases the conversion of phosphatidylcholine into arachidonic acid and inhibits the production of leukotrienes.

• 분석과학
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• 제5권4호
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• pp.477-484
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• 1992

형질 전환된 사철느타리버섯으로부터 초원심분리 및 설탕밀도 기울기법으로 44% 층에서 미토콘드리아를 분리정제하였다. ATPase와 ATP synthase의 최적 활성조건은 각각 pH 7.4, $60^{\circ}C$ 및 pH 7.5, $57^{\circ}C$였고, km값은 11.6mM과 8.4mM였다. ATPase는 기질농도 5~6mM의 ATP에서, ATP synthase는 5~10mM ADP 농도에서 활성이 높으며, 그 이상의 농도에서는 기질 저해를 받았다. ATPase/ATP synthase 모두 $Mg^{2+}$ 의존성 효소로 $G_{418}$으로 비경쟁적인 저해를 받았다. 효소의 아미노산 분석결과 hydrophobic 아미노산 잔기는 50.5%, small 아미노산 잔기는 56.1%, hydrogen bonding 아미노산 잔기는 43.7%, helix breaking 아미노산 잔기는 55.2%였다. 인지질을 분석한 결과 phosphatidyl glycerol, phosphatidyl choline 및 phosphatidyl ethanolamine으로 구성되었고 phosphatidyl serine과 phosphatidyl inositol은 전혀 없었다. 포화 지방산은 palmitate(51.31%)와 stearate(18.32%)의 함량이 많았고, 불포화 지방산($C_{18:1}$, $C_{18:2}$ 및 $C_{16:1}$)의 함량도 많았다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제30권3_4호
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• pp.326-338
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• 2003

신경회로망 설계 및 모델선택의 목표는 최적의 구조를 가지는 일반화 성능이 우수한 네트워크를 구성하는 것이다. 하지만 학습데이타에는 노이즈(noise)가 존재하고, 그 수도 충분하지 않기 때문에 최종적으로 표현하고자 하는 진확률 분포와 학습 데이타에 의해 표현되는 경험확률분포(empirical probability density) 사이에는 차이가 발생한다. 이러한 차이 때문에 신경회로망을 학습데이타에 대하여 과다하게 적합(fitting)시키면, 학습데이타만의 확률분포를 잘 추정하도록 매개변수들이 조정되어 버리고, 진확률 분포로부터 멀어지게 된다. 이러한 현상을 과다학습이라고 하며, 과다학습된 신경회로망은 학습데이타에 대한 근사는 우수하지만, 새로운 데이타에 대한 예측은 떨어지게 된다. 또한 신경회로망의 복잡도가 증가 할수록 더 많은 매개변수들이 노이즈에 쉽게 적합되어 과다학습 현상은 더욱 심화된다. 본 논문에서는 통계적인 관점을 바탕으로 신경회로망의 일반화 성능을 향상시키는 신경회로 망의 설계 및 모델 선택의 통합적인 프로세스를 제안하고자 한다. 먼저 학습의 과정에서 적응적 정규화가 있는 자연기울기 학습을 통해 수렴속도의 향상과 동시에 과다학습을 방지하여 진확률 분포에 가까운 신경회로망을 얻는다. 이렇게 얻어진 신경회로망에 자연 프루닝(natural pruning) 방법을 적용하여 서로 다른 크기의 후보 신경회로망 모델을 얻는다. 이러한 학습과 복잡도 최적화의 통합 프로세스를 통하여 얻은 후보 모델들 중에서 최적의 모델을 베이시안 정보기준에 의해 선택함으로써 일반화 성능이 우수한 최적의 모델을 구성하는 방법을 제안한다. 또한 벤치마크 문제를 이용한 컴퓨터 시뮬레이션을 통하여, 제안하는 학습 및 모델 선택의 통합프로세스의 일반화 성능과 구조 최적화 성능의 우수성을 검증한다.

• 한국균학회지
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• 제17권3호
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• pp.161-168
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• 1989

표고버섯(L. edodes) 중의 mitochondria는 설탕밀도단계기울기법에 따라 분리정제 하였다. 앞서 보고한 바와 같이, 각 파장별 빛조사(400-700nm)에 따른 mitochondrial ATPase와 ATP synthase의 활성도는 680nm와 470nm에서 각각 활성화되었다. 본 연구에서, 400nm 이하의 파장별 빛조사에 따른 mitochondrial ATPase 및 ATP synthase의 활성도는 380nm와 330nm에서 각각 활성화되었으며, 330nm 및 350에서 각각 억제되었다. FAD의 존재하에서, mitochondrial ATP synthase는 활성화 파장 및 억제 파장의 조사에 의하여 활성도가 각각 증가된 반면, mitochondrial ATPase의 활성도는 감소되었다. 그러나, NADH의 존재하에서, 이들 파장의 조사에 의한 효소의 활성도는 변화가 없었다. 또한, 두 효소는 각각의 활성화 파장 및 억제 파장이 조사됨에 따라 $FADH_2$를 FAD로 산화시키는 spectrum을 보였다. 이로써, 이 두 효소는 빛 조사에 의하여 생체내의 산화 환원반응의 산화제로 작용하였으며, 특히 mitochondrial ATP synthase의 활성화에 따른 광유발물질은 mitochondria 중에 존재하는 flavin 또는 flavoprotein으로 추정된다.

• 한국결정성장학회지
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• 제2권1호
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• pp.10-19
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• 1992

Soft Ferrites 가운데 대표적인 자성재료로써 최근에 개발된 Mn-Zn Ferrite는 높은 초기투자율과 포화자속밀도, 낮은 손실계수를 갖고 있으며 또한, 단결정으로써의 기계적 특성이 우수하며 VTR Head의 소재로 사용되는 중요한 전자부품이다. melt를 수용하는 도가니를 사용치 않아 결정으로의 불순물 침입이 없으며 halogen lamp로부터 방출된 적외선을 열원으로 하여 한 곳에 초점을 이루어 온도구배를 크게 유지하여 결정성장을 이루는 Floating Zone(FZ)법에 의해 Ar 및 $O_2$혼합가스 분위기 하에서 직경 8mm의 Mn-Zn Ferrite 단결정을 육성하였다. 성장 중 용융대에서의 최고온도는 $1650^{\circ}C$ 온도를 유지하였고 결정성장 속도는 10mm/hr, 회전속도는 20 rpm 이었으며 성장방위를 확인하기 위해 Laue 분석 및 XRD, TEM을 이용, 결정의 상등을 분석하였으며 화학적인 etching을 하여 광학현미경을 통해 etch pits 형상을 관찰하였다. 그리고 양질의 결정을 얻기 위해 원료봉 직경에 따른 결정화 속도와 적정한 melt직경과 길이에 대한 상관관계를 찾아내었고 또한 성장계면의 양상에 대해 고찰하였다.

• Journal of Yeungnam Medical Science
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• 제1권1호
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• pp.41-48
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• 1984

한국형 Agrobacterium tumefaciens의 분리 및 tumor inducing ($T_1$) plasmid의 유전적 특성을 비교 관찰하여 다음과 같은 결론을 얻었다. Agrobacterium군은 사과나무($A_1-A_3$), 미류나무($W_1{\sim}W_6$), 은사씨나무($P_1-P_3$) 및 장미($R_1$)의 crown gall tumor에서 도합 13종을 분리하였으며 각 군의 plasmid를 관찰한 결과 ATCC 15955보다 $P_1$ 및 $A_2$가 크기가 컸으며 $W_2$, $W_3$, $W_6$ 및 $P_3$는 작았으며 각균의 tumor 유도는 해바라기에 ATCC 15955와 Korean type $W_2$ ($KW_2$)을 접종한 것에서만 각각 접종 4주 및 6주만에 crown gall을 관찰하였다. 아울러 두균종의 $T_1$ plasmid($pT_1$)를 정제하여 몇종의 게한효소를 처리 하였으며 $pT_i$ ATCC 15955와 $pT_1KW_2$는 EcoR I 처리로 25개 및 27개의 band를, Hind III로 23개와 21개, BamH I으로 각각 20개 및 Hpa I으로 12개 및 27개의 band를 관찰하였으며 크기는 $pT_i$ ATCC 15955가 200 kbases(kb)로 $pT_1KW_2$가 87 kb로 관찰 되었다. 아울러 cctopine은 $W_1-W_6$ 및 $P_1-P_3$균에 의한 tumor조직에서 관찰 되었고 이들균을 octopine type균으로 사료 되었다.

• 대한수의학회지
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• 제31권4호
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• pp.491-500
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• 1991

This study was conducted to detect the serum antibodies in the experimentally toxoplasma infected dogs and street dogs by use the of an enzyme-linked immunosorbent assay (ELISA). And this test was performed on the polystylene microplate by coating with the tachyzoites soluble antigen of T gondii (RH strain), incubated with sera diluted then, added with HPO-conjugated rabbit anti-dog IgG and o-phenylenediamine used as a substrate. Tachyzoites of T gondii harvested from mouse peritoneal cavity were purified by 30, 40 and 50% Percoll density gradient centrifugation and used as the source of antigen. The results obtained were summarized as follows; 1. The highest ratio of positive to negative (P/N ratio) was obtained at the level of $l{\mu}g/ml$ protein concentration of antigen with the 1/4000 dilution of the conjugate measured by checker-board titration. It was regarded as the optimum concentration of the antigen and conjugate. 2. Cut-off value in this IgG ELISA was 0.375 that was determined by mean absorbance (at 492nm) of IFA negative serum added with the dauble value of the standard deviation $(mean{\pm}2S.D.)$. 3. Serum ELISA IgG antibodies to T gondii in the exyerimentally infected dogs were detected firstly at the Week 3 after inoculation and the highest titer was recognized at the Week 4, 5 and 6 after inoculation. 4. Stability of the antigen absorbed in the microplates that were preserved at $4^{\circ}C$ and $-25^{\circ}C$ separately were prolonged up to 3 weeks and 10 weeks at $4^{\circ}C$ and $-25^{\circ}C$, respectively. However the reproducibility was not reliable after the preservation of 4 weeks and longer. 5. Positive rate of the specific antibodies in 312 test sera was 28.5% and there was no significant differences between the male (27.8%) and female (29.5%), respectively. 6. The IgG ELISA was proved to be a specific procedure for the detection of antibodies to canine toxoplasma infection and also evaluated as a screening test for the large scale of test samples in laboratory.

• 천문학회보
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• 제43권1호
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• pp.34.2-35
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• 2018

Galaxy transition from star-forming to quiescent, accompanied with morphology transformation, is one of the key unresolved issues in extragalactic astronomy. Although several environmental mechanisms have been proposed, a deeper understanding of the impact of environment on galaxy transition still requires much exploration. My Ph.D. thesis focuses on which environmental mechanisms are primarily responsible for galaxy transition in different environments and looks at what happens during the transition phase using multi-wavelength photometric/spectroscopic data, from UV to mid-infrared (MIR), derived from several large surveys (GALEX, SDSS, and WISE) and our GMOS-North IFU observations. Our multi-wavelength approach provides new insights into the *late* stages of galaxy transition with a definition of the MIR green valley different from the optical green valley. I will present highlights from three areas in my thesis. First, through an in-depth study of environmental dependence of various properties of galaxies in a nearby supercluster A2199 (Lee et al. 2015), we found that the star formation of galaxies is quenched before the galaxies enter the MIR green valley, which is driven mainly by strangulation. Then, the morphological transformation from late- to early-type galaxies occurs in the MIR green valley. The main environmental mechanisms for the morphological transformation are galaxy-galaxy mergers and interactions that are likely to happen in high-density regions such as galaxy groups/clusters. After the transformation, early-type MIR green valley galaxies keep the memory of their last star formation for several Gyr until they move on to the next stage for completely quiescent galaxies. Second, compact groups (CGs) of galaxies are the most favorable environments for galaxy interactions. We studied MIR properties of galaxies in CGs and their environmental dependence (Lee et al. 2017), using a sample of 670 CGs identified using a friends-of-friends algorithms. We found that MIR [3.4]-[12] colors of CG galaxies are, on average, bluer than those of cluster galaxies. As CGs are located in denser regions, they tend to have larger early-type galaxy fractions and bluer MIR color galaxies. These trends can also be seen for neighboring galaxies around CGs. However, CG members always have larger early-type fractions and bluer MIR colors than their neighboring galaxies. These results suggest that galaxy evolution is faster in CGs than in other environments and that CGs are likely to be the best place for pre-processing. Third, post-starburst galaxies (PSBs) are an ideal laboratory to investigate the details of the transition phase. Their spectra reveal a phase of vigorous star formation activity, which is abruptly ended within the last 1 Gyr. Numerical simulations predict that the starburst, and thus the current A-type stellar population, should be localized within the galaxy's center (< kpc). Yet our GMOS IFU observations show otherwise; all five PSBs in our sample have Hdelta absorption line profiles that extend well beyond the central kpc. Most interestingly, we found a negative correlation between the Hdelta gradient slopes and the fractions of the stellar mass produced during the starburst, suggesting that stronger starbursts are more centrally-concentrated. I will discuss the results in relation with the origin of PSBs.

• Nutrition Research and Practice
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• 제8권4호
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• pp.368-376
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• 2014

BACKGROUND/OBJECTIVES: The objectives of this study were to investigate the effects of lycopene on the migration, adhesion, tube formation capacity, and p38 mitogen-activated protein kinase (p38 MAPK) activity of endothelial progenitor cells (EPCs) cultivated with high glucose (HG) and as well as explore the mechanism behind the protective effects of lycopene on peripheral blood EPCs. MATERIALS/METHODS: Mononuclear cells were isolated from human peripheral blood by Ficoll density gradient centrifugation. EPCs were identified after induction of cellular differentiation. Third generation EPCs were incubated with HG (33 mmol/L) or 10, 30, and $50{\mu}g/mL$ of lycopene plus HG. MTT assay and flow cytometry were performed to assess proliferation and apoptosis of EPCs. EPC migration was assessed by MTT assay with a modified boyden chamber. Adhesion assay was performed by replating EPCs on fibronectin-coated dishes, after which adherent cells were counted. In vitro vasculogenesis activity was assayed by Madrigal network formation assay. Western blotting was performed to analyze protein expression of both phosphorylated and non-phosphorylated p38 MAPK. RESULTS: The proliferation, migration, adhesion, and in vitro vasculogenesis capacity of EPCs treated with 10, 30, and $50{\mu}g/mL$ of lycopene plus HG were all significantly higher comapred to the HG group (P < 0.05). Rates of apoptosis were also significantly lower than that of the HG group. Moreover, lycopene blocked phosphorylation of p38 MAPK in EPCs (P < 0.05). To confirm the causal relationship between MAPK inhibition and the protective effects of lycopene against HG-induced cellular injury, we treated cells with SB203580, a phosphorylation inhibitor. The inhibitor significantly inhibited HG-induced EPC injury. CONCLUSIONS: Lycopene promotes proliferation, migration, adhesion, and in vitro vasculogenesis capacity as well as reduces apoptosis of EPCs. Further, the underlying molecular mechanism of the protective effects of lycopene against HG-induced EPC injury may involve the p38 MAPK signal transduction pathway. Specifically, lycopene was shown to inhibit HG-induced EPC injury by inhibiting p38 MAPKs.