• 한국표면공학회지
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• 제37권2호
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• pp.71-75
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• 2004

The technology of $C_{60}$ fullerite films preparation by means of gas-phase deposition and structure of fullerite films are described. A three-channel flow plant was used to obtain fullerite films. The films were deposited in the flow of inert gas under reduced pressure onto a cooled silicon or sapphire substrate placed inside the reaction chamber of the plant. The plant allows one to obtain the films of pure fullerenes and to synthesise the films from fullerene compounds and doped fullerenes. The structure of two types of films were investigated by FE-SEM and SEM techniques: pure fullerite films onto silicon and sapphire substrates as well as compound films were studied by FE-SEM technique. All samples have shown columnar structure with high level of porosity. The synthesis of films composed of fullerene and its compounds for use in electronics is demonstrated to be promising. For example, experiments confirm the possibility to use fullerite films in sensor electronics to produce humidity and thermal sensors. It is also possible to use the sensitivity of these films to isotropic pressure. The experiments with $C_{60}$-Cu-J films have shown quite strong dependence of their resistance on pressure of different sort of medium-gas that could be used in gas-sensitive sensors. The structure and preparation technology of resistive sensor based on fullerite films are described.bed.

• 한국입자에어로졸학회지
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• 제6권2호
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• pp.51-59
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• 2010

ZnO quantum dots embedded in a silica matrix without agglomeration were synthesized from $TEOS:Zn(NO_3)_2$ solutions in one-step process by aerosol-gel method. It was successfully demonstrated that the size of ZnO Q-dots could be controlled from 2 to 7 mm verified by a high resolution transmission electron microscope observation. The line scanning energy dispersive X-ray spectroscopy(EDS) revealed that the Q-dots existed preferentially inside SiO2 sphere when Zn/Si < 0.5. However, the Q-dots distributed homogeneously all over the sphere when Zn/Si > 1.0. Blue-shifted UV/Vis absorption peak observation confirmed the quantum size effect on the optical properties. The photoluminescence(PL) emission peaks of the powders at room temperature were consistent with previous reports in the following aspects: 1) PL characteristics are dominated by two peaks of deep-level defect-related emissions at 2.4 - 2.8 eV, 2) the first defect-related peak at 2.4 eV was blue shifted due to the quantum size effect with decreasing the concentration of $Zn(NO_3)_2$(decreasing the size of ZnO q dots). More interestingly, the existence of surface-exposed ZnO q dots affects greatly the second defect PL peak at 2.8 eV.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.131-137
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• 2001

Previous work has identified that only the catabolite responsive element A (creA; previously called cre-2) out of two potential cre sequences (cre-1: nucleotide +160 to +173 and cre-2: +173 to +186), recognized within the coding region of the xylanaseA gene (xynA) of Bacillus stearothermophilus No.236, was actually, was actually involved in the carbon catabolite repression(CCR) of xynA expression in B. subtilis. However, the level of CCR of xynA expression in the original B.stearothermophilus No.236 strain (70-fold repression). Therefore, to search for an additional cre element in the promoter region, the upstream region of the xynA gene was subcloned by chromosome walking, and as a result, another potential cre element (nucleotide -124∼-137; designated creB) was recognized in this region. The cre-like sequence revealed a high homology to the cre consensus sequence. The xylanase activity of B. subtilis MW15 bearing pWPBR14 (containing creA and creB) cultured in a medium containing xylose as the sole carbon source was about 7.7 times higher than that observed for the same culture containing glucose. B. subtilis MW15 bearing pWPBR23 (containing only creA) produced an activity about 2.4 times higher. This pattern of CCR was confirmed using derivatives of xynA::aprA fusion plasmids. Furthermore, a measurement of the amounts of the xynA transcript showed a similar pattern as that for the production of xylanase. In addition, the synthesis of xylanase in B. subtilis QB7115 [a catabolite control protein A (ccpA) mutant strain] carrying pWPBR14 was almost completely relieved from glucose repression. Together, these results lead to a conclusion that the CCR of the expression of the xynA gene is mediated by CcpA binding at creA and creB sites in B. subtilis.

• Applied Biological Chemistry
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• 제36권3호
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• pp.191-196
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• 1993

본 연구는 합성기질인 $X-{\alpha}-Gal$를 이용하여 발효유 및 유제품내의 Bifidobacteria 생균수를 측정할 목적으로 하였다. 젖산균과 Bifidobacteria의 ${\alpha}-galactosidase$ specific activity를 측정한 결과 Bifidobacteria 균주에서는 높은 ${\alpha}-galactosidase$ activity를 가지고 있었으며, 그 중 Bif. longum KCTC 3215의 specific activity는 8.57 unit/mg protein으로 가장 높게 나타났다. Lactobacillus, Streptococcus, Pediococcus와 Leuconostoc 균주에서는 활성이 미약하거나 없었다. 합성기질인 $X-{\alpha}-Gal$을 MRS agar 배지에 $100{\;}{\mu}M$ 첨가한 결과 Bifidobacteria는 blue colony로, Lac. bulgaricus, Lac. casei와 Leu. mescenteroides 균주는 light blue colony로, 그 외 젖산균에서는 white colony로 나타났다.

• Journal of Nutrition and Health
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• 제36권8호
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• pp.819-827
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• 2003

Linoleic acid [LA; 18: 2 (n-6)] is the most abundant polyunsaturated fatty acid in human skin. The exclusion of LA from diet induces epidermal hyperproliferation, which is reversible by the inclusion of LA in diet, and hence, LA is heralded as an essential fatty acid (EFA). Since safflower oil (SO) has been widely recognized as the major dietary source of LA and Arctii Fructus (Arctium lappa L.) is recently reported to contain high level of LA, we compared the antiproliferative effects of SO and Arctii Fructus in this study. Epidermal hyperproliferation was induced in guinea pigs by hydrogenated coconut oil (HCO) diet for 8 wk. During following 2 wk, EFA deficient guinea pigs were fed diets of safflower oil (group HS), water extract of Arctii Fructus (group AW) or organic extract of Arctii Fructus (group AO). Normal control group was fed SO containing diet (group SO) and EFA deficient group was fed HCO containing diet (group HCO) for 10 wk. Epidermal hyperproliferation was reversed in groups AO (55.9% of group HCO) and HS(74.1% of group HCO). However, the thymidine incorporation into epidermal DNA of group HS was greater than of normal control group SO. Epidermal hyperproliferation was not reversed in group AW. The accumulations of LA into phospholipids and ceramides, and of 13-hydroxyoctadecadienoic acid (13-HODE), the potent antiproliferative metabolite of LA in the epidermis of group AO were greater than of group HS. In contrast, the de novo synthesis of ceramides, the major lipids maintaining epidermal barrier, did not differ between all of groups. Together, our data demonstrate that organic extract of Arctii Fructus is more prominent than safflower oil in reversing epidermal hyperproliferation by inducing the higher accumulations of LA and 13-HODE in the epidermis of guinea pigs.

• IMMUNE NETWORK
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• 제10권1호
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• pp.15-25
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• 2010

Background: Rat mast cells were regarded as a good model for mast cell function in immune response. Methods: Rat bone marrow mast cells (BMMC) were prepared both by recombinant rat IL-3 (rrIL-3) and by recombinant mouse stem cell factor (rmSCF), and investigated for both proliferation and differentiation in time course. Rat BMMC was induced by culture of rat bone marrow cells (BMCs) in the presence of both rrIL-3 (5 ng/ml) and rmSCF (5 ng/ml). Culture media were changed 2 times per week with the cell number condition of $5{\times}10^4/ml$ in 6 well plate. Proliferation was analyzed by cell number and cell counting kit-8 (CCK-8) and differentiation was by rat mast cell protease (RMCP) II and histamine. Results: Cell proliferation rates reached a maximum at 8 or 11 days of culture and decreased thereafter. However, both RMCP II production and histamine synthesis peaked after 11 days of culture. By real time RT-PCR, the level of histidine decarboxylase mRNA was more than 500 times higher on culture day 11 than on culture day 5. By transmission electron microscopy, the cells were heterogeneous in size and contained cytoplasmic granules. Using gated flow cytometry, we showed that cultured BMCs expressed high levels of $Fc{\varepsilon}RI$ and the mast cell antigen, ganglioside, on culture day 11. Conclusion: These results indicate that rat BMMCs were generated by culturing BMCs in the presence of rrII-3 and rmSCF and that the BMMCs have the characteristics of mucosal mast cells.

• 전자공학회논문지
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• 제50권1호
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• pp.124-130
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• 2013

본 논문에서는 고성능 H.264/AVC 부호기 설계를 위해 낮은 연산 복잡도를 가지는 움직임 예측 알고리즘과 하드웨어 구조를 제안한다. 제안하는 움직임 예측 알고리즘은 주변 매크로블록들의 움직임 벡터와 방향성으로 유동적인 초기 탐색점과 탐색패턴으로 정확한 초기 탐색점을 설정한다. 주변 매크로블록들의 움직임 벡터를 사용하여 적은 수의 탐색점으로 움직임 예측이 가능하며, 적은 수의 탐색점으로 인해 연산량과 수행 사이클을 감소시킨다. 제안한 움직임 예측 하드웨어를 TSMC 0.18um CMOS 표준 셀 라이브러리 이용해 합성한 결과 217.92k 개의 로직 게이트로 구현되며 최대동작 주파수는 166MHz이다. 제안한 움직임 예측의 하드웨어 구조는 하나의 매크로 블록을 부호화 하는데 312사이클 소요되어 기존 하드웨어 구조대비 성능이 69% 향상됨을 확인하였다.

• 정보처리학회논문지A
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• 제9A권3호
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• pp.379-386
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• 2002

본 논문은 자원제약 조건에서 파이프라인 데이터패스 합성을 위한 스케줄링 방법이며, 우선순위 함수를 사용하여 스케줄할 연산을 선택하는 방법들과는 달리 연산들의 배정가능범위를 점진적으로 축소하여 스케줄한다. 제안방법은 스케줄링 알고리즘과 자원제약 위반을 검출하는 판단알고리즘으로 구성되며, 연산의 배정 가능한 제어단계의 처음 또는 마지막 단계에 임시로 연산을 배정하여 스케줄링 해가 존재하는지를 평가한다. 만약 해를 발견할 수 없다면 이는 자원제약 위반에 의해 연산을 그 제어단계에 배정하는 것이 불가능함을 의미하기 때문에 그 제어단계를 제거하며, 모든 연산에 대하여 배정가능범위 축소가 없을 때까지 이 과정을 반복한다. 벤치마크에 대한 실험결과는 다른 방법들과 비교해서 개선된 스케줄링 결과를 보인다.

• KSBB Journal
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• 제24권1호
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• pp.96-100
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• 2009

본 연구에서는 저온에서의 재조합 단백질 생산성 향상을 위하여 저온에서 RNA 샤페론 활성을 지닌다고 알려진 CspA 단백질의 발현이 서로 다른 온도에서 대장균의 성장 및 GFP의 발현 속도에 어떻게 영향을 미치는지를 살펴보았다. $20^{\circ}C$, $25^{\circ}C$, $37^{\circ}C$에서는 세포 성장 및 GFP의 생산이 CspA의 발현에 영향을 받지 않았으나, $15^{\circ}C$에서는 GFP의 총 생산성이 CspA의 동시 발현에 의해 향상되었으며 이는 세포 성장 속도의 향상에 기인함을 확인하였다. 결론적으로 CspA의 발현은 $15^{\circ}C$에서 세포 당 재조합 단백질 생산량의 증가에는 영향을 미치지 않으나, 즉 재조합 단백질의 번역 효율에는 큰 영향을 미치지 않으나, 대장균 성장 속도에 영향을 미치며, 이를 통해 재조합 단백질의 총 생산량 향상을 유도 할 수 있을 것으로 기대된다.

• 대한전자공학회논문지SP
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• 제43권1호
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• pp.39-44
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• 2006

본 논문에서는 정지영상에 대해서 borda count 방법을 적용하여 MPEG-7 서술자기반 검색 결과 리스트의 조합에 대한 방법을 제한한다 대부분의 검색 엔진의 경우 MPEG극에서 정의하고 있는 서술자중 하나의 서술자만을 가지고 검색을 수행하고 있다. 이러한 경우 영상의 특성에 따라 검색 성능이 좋을 수도 있지만 그렇지 않을 수도 있다. 따라서 여러 가지 기술자들의 검색 결과를 조합하여 결과 리스트를 작성하는 방법이 요구되고 있다. 이에 따라 본 논문에서는 relevance feedback 알고리즘을 이용한 검색 시스템에 대하여, 여러 가지 서술자에 대한 검색 결과에 대한 결과 리스트를 borda count 방법을 이용하여 각각의 서술자에 의한 검색 결과를 조합하여 하나의 결과 리스트를 작성하는 방법을 제안한다.