• 한국진공학회지
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• 제7권4호
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• pp.361-367
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• 1998

유기 박막 트렌지스터의 활성층으로 사용하기 위하여 공액성 소중합체인 $\alpha$ -sexithiophene($\alpha$-6T)이라는 시료를 가지고 유기 분자선 증착법(OMBD)을 이용하여 박막 을 제작하였으며 $\alpha$-6T박막의 성막 조건에 따른 박막의 분자 배향, 결정구조 그리고 표면 특성을 알아보기 위해 angle-resolved UV/visible absorption spectroscopy, X-ray diffractometry(XRD) 그리고 atomic force microscopy(AFM)를 이용하였으며 그 분석 결과 성막 조건에 관계없이 모두 monoclinic한 결정구조를 갖으나, 초고진공, 낮은 성막 속도, 기 판의 온도가 높은 조건일 경우 $\alpha$-6T 분자들이 기판에 수직적으로 배열한다는 것을 확일할 수 있었다.

• 한국식품영양학회지
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• 제10권2호
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• pp.180-185
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• 1997

찹쌀 20%, 엿기름 4%를 가하여 7시간 동안 당화시켜 제조한 식혜는 말통스 10.1%, 한계덱스트린 7.3%, 말토트링스 1.3%, 글루코오스 0.18%, 밥알 1.75%를 나타냈다. 알코올 침전, Biogel P-2의 겔 크로마토그래피로 식혜의 한계덱스트린을 정제하여 1H-NMR 분석한 결과 한계덱스트린은 $\alpha$-1,4-글루코시드 결합과 $\alpha$-1,6-글루코시드 결합이 5:1로 이루어졌고, pullulanase 처리한 결과 말토오스와 말토헥사오스까지의 분포를 나타내어 멥쌀식혜에서 얻은 한계덱스트린가 구조가 같은 결과이다. 밥알의 당함량은 26.4%, 단백질 함량은 41.6%를 나타냈다. 참쌀식혜의 한계덱스트린과 밥알에 30unit/ml의 $\alpha$-아밀라아제, 글\ulcorner아밀라아제, $\alpha$-글루코시다아제, $\beta$-아밀라아제를 작용시킨 결과 글루코아밀라아제 외에는 일부밖에 가수분해하지 at하였다. 인체의 효소인 $\alpha$-아밀라아제와 $\alpha$-글루코시다아제를 함께 작용시킨 결과 한계덱스트린의 가수분해율은 18%, 밥알의 가수분해율은 26%를 나타냈다.

• 천문학회지
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• 제51권1호
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• pp.5-16
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• 2018

We investigate the escape of $Ly{\beta}$ from emission nebulae with a significant population of excited hydrogen atoms in the level n = 2, rendering them optically thick in $H{\alpha}$. The transfer of $Ly{\beta}$ line photons in these optically thick regions is complicated by the presence of another scattering channel leading to re-emission of $H{\alpha}$, alternating their identities between $Ly{\beta}$ and $H{\alpha}$. In this work, we develop a Monte Carlo code to simulate the transfer of $Ly{\beta}$ line photons incorporating the scattering channel into $H{\alpha}$. Both $H{\alpha}$ and $Ly{\beta}$ lines are formed through diffusion in frequency space, where a line photon enters the wing regime after a fairly large number of resonance scatterings with hydrogen atoms. Various line profiles of $H{\alpha}$ and $Ly{\beta}$ emergent from our model nebulae are presented. It is argued that the electron temperature is a critical parameter which controls the flux ratio of emergent $Ly{\beta}$ and $H{\alpha}$. Specifically for $T\;=\;3{\times}10^4\;K$ and $H{\alpha}$ line center optical depth $\tau{\alpha}\;=\;10$, the number flux ratio of emergent $Ly{\beta}$ and $H{\alpha}$ is ~ 49 percent, which is quite significant. We propose that the leaking $Ly{\beta}$ can be an interesting source for the formation of $H{\alpha}$ wings observed in many symbiotic stars and active galactic nuclei. Similar broad $H{\alpha}$ wings are also expected in $Ly{\alpha}$ emitting halos found in the early universe, which can be potentially probed by the James Webb Telescope in the future.

• 한국양식학회지
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• 제9권1호
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• pp.57-63
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• 1996

범가자미 난모세포의 최종성숙(GVBD=germinal vesicle breakdown) 유도를 위한 HCG (human chorionic gonadotropin)와 스테로이드 호르몬들의 효능 비교실험이 in vitro에서 이루어졌다. 실험에 사용한 스테로이드 호르몬, progestogens (progesterone, $17\alpha$-hydroxyprogesterone, $17\alpha$-hydroxy, $20\beta$-dihydroprogesterone)중에서는 $17\alpha$-hydroxy, $20\beta$-dihydroprogesterone ($17\alpha20{\beta}OHP$)이 매우 효과적으로 나타났으며, $17\alpha20{\beta}OHP$와 HCG와의 비교실험에서는 이들 모두 GVBD 유도에 효과적인 것으로 나타났다. 특히 $17\alpha20{\beta}OHP$는 저농도($10\~50$ ng/ml)에서도 효과적이며, HCG는 사용한 농도(50, 100, 500 IU/ml)사이에 유의한차를 보이지 않았다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권3호
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• pp.342-347
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• 2003

The enzyme $20{\alpha}$-hydroxysteroid dehydrogenase ($20{\alpha}$-HSD) catabolizes progesterone to $20{\alpha}$-dihydroprogesterone ($20{\alpha}$-OHP), and is appeared in rat corpora luteal and placenta. A polled samples of 10-15 placental and ovarian tissues collected from each individual rat were subjected to measurement of $20{\alpha}$-HSD activity. A $20{\alpha}$-HSD activity in the cytosol fraction was based on the generation of NADPH. In this study, it is designed to study cytosolic $20{\alpha}$-HSD activity in rat ovarian and placenta during pregnancy, and its relationship to embryonic mortality. It was found that from days 5 to 18 of pregnancy the $20{\alpha}$-HSD activities steady by decreased but at parturition time rapidly increased in ovary. On the other hand, placental cytosolic $20{\alpha}$-HSD activities were high detected from days 8 to 10 of pregnancy, not detectable from days 11 to 20 of pregnancy, but again very high at the time of parturition. Analysis of DEAE column chromatography revealed that two different types of $20{\alpha}$-HSD (HSD-1 and HSD-2) were found with similar activity in the placental cytosol on day 10 of pregnancy. The number of fetuses on day 10 of pregnancy was 15.4 and decreased significantly to 12.9 on day 12. The results suggested that expression of $20{\alpha}$-HSD in the placental tissues seems to be related the number of fetal survived in the specific time (days 11 and 12) which spontaneous fetal loss occurs.

• Preventive Nutrition and Food Science
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• 제4권1호
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• pp.52-56
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• 1999

This study has examined the effects of Aralia elata Seemann ethanol extract on antioxidant enzyme systems inrats along with benzo($\alpha$) pyrene(B(a)P) administration . The ethanol extract of Aralia elata Seemann (50mg/kg body wt.) was fed to rats for 4 weeks by stomach tubing. The extract administration increased antioxidant activities of glutathione sulfur transferase(GST) comparing to the control. also total superoxide dismutase(SOD) and Cu, Zn-SOD activities were stimulated. Catalase activities were increased by 50% with the extract feeding compared to the control . Combined administration of B($\alpha$)P and the extract increased GST activity in B($\alpha$) P group. Although total SOD acitivity was decreased , Cu, Zn-SOD was greately increased from 0.10unit to 0.18 unit and catalase activity also was increased compared to the group of B($\alpha$) P. GST activity in CLE group was 1.32 unit, increased by 33% comparing to the group CL of 0.99unit. Cu, Zn-SOD and catalase activities in thegroup fed high fat and ethanol extracts were increased by 25% and 39%, respectivley comparing to the group of high fat. In addition , total SOD was decreased but, Cu, Zn-SOD acitivity was increased from 0.09 unit to 0.18unit. Catalase activity was 76.05 unit in the group of B($\alpha$) P and extract comparing to 65.26 units in B($\alpha$)P group. Serum $\alpha$-tocopherol of rat was markedly increased by theextract. Administration of B9$\alpha$)P reduced $\alpha$-tocopherol levels in the serum, on the other hand, lard in the diet increased $\alpha$-tocopherol levels in the serum. The above results indicate that Aralia bud exerts antioxidant functions in vivo against B($\alpha$)P. Further research may be necessary for the identification fo the biologically active material.

• 대한의용생체공학회:의공학회지
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• 제26권4호
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• pp.223-230
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• 2005

This paper presents a new approach to investigate spatial correlation between independent components of brain alpha activity in functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). To avoid potential problems of simultaneous fMRI and EEG acquisitions in imaging pure alpha activity, data from each modality were acquired separately under a 'three conditions' setup where one of the conditions involved closing eyes and relaxing, thus making it conducive to generation of alpha activity. The other two conditions -- eyes open in a lighted room or engaged in a mental arithmetic task, were designed to attenuate alpha activity. Using a Mixture Density Independent Component Analysis (MD-ICA) that incorporates flexible non-linearity functions into the conventional ICA framework, we could identify the spatiotemporal components of fMRI activations and EEG activities associated with the alpha rhythm. Then, the sources of the individual EEG alpha activity component were localized by a Maximum Entropy (ME) method that is specially designed to find the most probable dipole distribution minimizing the localization error in sense of LMSE. The resulting active dipoles were spatially transformed to 3D MRls of the subject and compared to fMRI alpha activity maps. A good spatial correlation was found in the spatial distribution of alpha sources derived independently from fMRI and EEG, suggesting the proposed method can localize the cortical areas responsible for generating alpha activity successfully in either fMRI or EEG. Finally a functional connectivity analysis was applied to show that alpha activity sources of both modalities were also functionally connected to each other, implying that they are involved in performing a common function: 'the generation of alpha rhythms'.

• 한국미생물·생명공학회지
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• 제19권5호
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• pp.477-486
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• 1991

Aspergillus niger가 생산하는 $\alpha$-galactosidase의 효소학적 성질을 조사하기 위하여 시험균주를 밀기울 배양한 후 생성된 $\alpha$-galactosidase를 염석, 이온교환 크로마토그래피 및 겔 여과 등의 방법으로 정제한 후 정제효소의 효소학적 성질을 검토하였다. Asp. niger를 밀기울 배지에서 $30^{\circ}C$, 4일 배양했을 때 효소활성이 가장 높았으며 $\alpha$-galactosidase는 황산암모늄 염석, DEAE-cellulose 및 DEAE-Sephadex A-50 이온교환 크로마토그래피, sephadex G-150 겔 여과 등에 의하여 23.7배까지 정제되었으며 비활성이 1,229U/mg.protein, 수율 14이었고 HPLC와 PAGE에 의해 순도가 확인되었다.

• 대한의생명과학회지
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• 제24권3호
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• pp.213-220
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• 2018

Triglyceride (TG) is known to be associated with inflammatory disease including atherosclerosis. In a variety of atherosclerosis models, T lymphocytes are localized in the earliest lesions of atherosclerosis. T cell associated cytokines such as $TNF-{\alpha}$ and $IFN-{\gamma}$ have pre-dominant inflammatory effects in chronic vascular diseases. In our previous study, we found that the expression of $TNF-{\alpha}$ and its receptor, $TNF-{\alpha}R$ was increased when Jurkat T lymphocyte cell lines were exposed to TGs. Therefore, experiments were conducted to determine which cell signaling pathway are involved in the increase of $TNF-{\alpha}$ and $TNF-{\alpha}R$ expression by TGs. To identify signal transduction pathways involved in TG-induced upregulation of $TNF-{\alpha}$, we treated TG-exposed Jurkat T cells with specific inhibitors for MEK1, PI3K, $NF-{\kappa}B$ and PKC. We found that inhibition of the MEK1 pathway blocked TG-induced upregulation of $TNF-{\alpha}$. However, the expression level of $TNF-{\alpha}R$ did not change with any signal transduction inhibitor. Based on this observation, we suggest that increase of exogenous TG induces increase of $TNF-{\alpha}$ expression through MEK1 pathway in Jurkat T cells. In addition, it was confirmed that the increase of $TNF-{\alpha}$ and $TNF-{\alpha}R$ expression by TGs occurs via different pathways.

• 한국미생물·생명공학회지
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• 제13권4호
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• pp.349-354
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• 1985

Plasmid pBR322와 runaway Plasmid pSY343을 vector로 사용하여 E. stearothermophilus IAM 11062내의 $\alpha$-amylase 유전자를 E. coli내에 클로닝 하였다. 이때 얻어진 $\alpha$-amylase유전자는 제한효소 Hind III의 말단을 갖고 있는 4.7kb의 크기였으며 E. coli내에서 이들 유전자는 비교적 안정적 있게 유지되고 발현되었다. 재조합 $\alpha$-amylase유전자가 클로닝된 E. coli는 B. stearothermophilus IAM 11062보다 3배의 $\alpha$-amylase를 더 많이 생성하였다. EDTA를 사용한 osmotic shock 방법에 의하여 E. coli내에서 생성된 $\alpha$-amylase는 그 효소 생성량의 75%정도가 periplasm에 존재함이 밝혀졌다. 재조합된 $\alpha$-amylase 유전자에 의해서 E. coli에서 생성된 $\alpha$-amylase는 최적 작용온도가 55$^{\circ}C$로서 이들의 열안정성과 분자량(61,000)도 B. stearothermophilus IAM 11062의 $\alpha$-amylase와 거의 동일하게 나타나 E. coli와 B. stearothermophilus IAM 11062에서 생성된 $\alpha$-amylase는 효소학적 성질이 같음을 보여주었다.