• Food Science and Biotechnology
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• 제15권3호
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• pp.441-446
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• 2006

The biological effects of heating and chemical treatment on castor meal were investigated in order to develop a procedure to inactivate its antigenic activity in a way that is suitable for industrial applications. A 1% solution of purified castor bean allergen (CB-1A) was heat-treated with or without exposure to NaOH and NaOCI (250 ppm each). CB-1A exhibited extreme stability when heat-treated alone. In the presence of NaOH and NaOCl, CB-1A showed a drastic decrease in antigenic activity as the temperature surpassed the critical level of $70^{\circ}C$. The gradual disappearance of disc gel electrophoresis bands presumably responsible for the allergenicity of CB-1A, along with the significant losses of the amino acids phenylalanine, methionine, arginine, histidine, and cysteine correlated with the loss of CB-1A activity. CB-1A showed a single symmetrical band in SDS acrylamide gel electrophoresis with an estimated molecular weight of 6,000 daltons. The chemical and heat treatments reduced the disulfide bond content of CB-1A by 9.1% with a coincident increase in sulfhydryl bonds.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권2호
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• pp.276-279
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• 2015

This paper presents two 3-stage D-band stacked amplifiers developed in a $0.13-{\mu}m$ SiGe BiCMOS technology, employed to compare the conventional cascode topology and the common-base (CB)/CB stacked topology. AMP1 employs two cascode stages followed by a CB/CB stacked stage, while AMP2 is composed of three CB/CB stacked stages. AMP1 showed a 17.1 dB peak gain at 143.8 GHz and a saturation output power of -4.2 dBm, while AMP2 showed a 20.4 dB peak gain at 150.6 GHz and a saturation output power of -1.3 dBm. The respective power dissipation was 42.9 mW and 59.4 mW for the two amplifiers. The results show that CB/CB stacked topology is favored over cascode topology in terms of gain near 140 GHz.

• Elastomers and Composites
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• 제22권3호
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• pp.195-203
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• 1987

본(本) 연구(硏究)는 기능성(機能性) elastomer 개발(開發)의 일환(一環)으로서 1-chlorobutadiene-butadiene copolymer(CB-BR)의 수가교(水架橋)에 의(依)한 기능성(機能性)의 향상(向上)에 그 목적(目的)을 두었으며 가교제(架橋劑)로서 3-aminopropyltriethoxysilane을 이용(利用)하여 CB-BR의 활성염소(活性鹽素)와의 용액반응(溶液反應)을 속도론적(速度論的)으로 해석(解析)하였다. 그리고 APS와 CB-BR을 실제공정(實際工程)에서 배합(配合)하여 수중가교반응(水中架橋反應)을 진행(進行)시켜 이에 따른 물성(物性) 검토(檢討)를 하므로써 다음과 같은 결론(結論)을 얻었다. 1. CB-BR은 용액계(溶液系)에서 APS와 용이(容易)하게 반응(反應)하며 이때의 반응(反應) 속도상수(速度常數) 및 활성화(活性化)에너지는 다음과 같다. 2. CB-BR+APS 수가교체(水架橋體)의 최적(最適) press 조건(條件)은 $150^{\circ}C{\cdot}20$분(分)이고 이들 가교체(架橋體)의 물성(物性)을 고무탄성체(彈性體) 이론(理論)에 의하여 가교진행(架橋進行)의 타당성(妥當性)을 검토(檢討)한 결과 이론치(理論値) q=1에 근접(近接)함을 알았다.

• 한국수정란이식학회지
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• 제32권3호
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• pp.95-104
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• 2017

This study was conducted to establish the optimal chemical post-activation conditions in porcine embryonic development after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) using 4 different chemical compositions (cytochalasin B (CB), cyclohexamide (CHX), demecolcine (DC), 6-dimethylaminopurine (DMAP). Porcine embryos were produced by PA and SCNT and then, cultured for post-activation with CB ($7.5{\mu}g/mL$), CB ($7.5{\mu}g/mL$) + CHX ($10{\mu}g/mL$), CB ($7.5{\mu}g/mL$) +DC ($0.4{\mu}g/mL$), and CB ($7.5{\mu}g/mL$) + DMAP (2 mM). In PA embryonic development, cleavage rates have been significantly higher in CB group (94.7%) and CB+DMAP group (94.1%) than that of CB+CHX and CB+DC group (88.1 and 84.3%, respectively). There have been no significant differences in blastocyst formation rates among the four groups. In cell number of blastocyst was shown in CB group (42.3%) significantly higher than CB+CHX and CB+DC group (40.6 and 40.6%, respectively). In SCNT embryonic development, CB+DMAP group (89.7%) significant differences were found on embryo cleavage rates when compared with other three groups. Blastocyst formation rates in CB+DMAP group (26.9%) were significantly higher when compared with CB, CB+CHX, and CB+DC groups (25.5, 20.2, and 22.1%, respectively). In blastocyst cell number, CB+DMAP group (41.4%) was found higher significant difference compared with other three groups. Additionally, we have investigated survivin expression in early development stages of porcine SCNT embryos for more confirmation. Our results establish that CB group and CB+DMAP group for 4 h during post-activation improves pre-implantation improvement of PA and SCNT embryos.

• Fibers and Polymers
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• 제1권1호
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• pp.32-36
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• 2000

An alternative strategy to .educe the percolation threshold of carbon black (CB) in polymer blends was investigated using random copolymer ternary blends of polystyrene (PS), poly(methyl methacrylate)(PMMA), and a styrene-methyl methacrylate random copolymer (SMMA). The target morphology was to selectively locate CB particles in the encapsulating layer of SMMA during melt mixing. The CB used in this study is BP-2000 from Cabot and has a strong selective affinity to PS. Even when the CB was premixed with SMMA, it moves to the PS phase during the melt mixing. However, we also observed the CB particles located at the interface between SMMA and PS phases. Through this study it is found that the interaction between polymers and CB particles is critical for selectively localizing CB particles in multi-component polymer blends. Although appropriate processing condition may retard the movement of CB particles to the polymer phase with affinity, it cannot prevent it completely and locate them to the SMMA phase, which is not thermodynamically favored. To locate CB particles in an encapsulating layer of ternary polymer blends, first of all, polymers forming it should have selective affinity to CB.

• 한국수정란이식학회지
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• 제19권1호
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• pp.35-42
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• 2004

본 연구는 돼지 배아의 유리화 동결 시 CB 처리군과 CB 비처리군의 영향을 비교하였다. CB의 농도별, 처리 시간별로 처리한 뒤 유리화 동결 융해 후 정상적인 형태 회수율과 생존률을 각각 조사하였다. 1. CB를 전 처리한 군과 비처리군의 정상적인 형태율이 각각 84.2%, 81.9%로 유의한 차이가 없었으나, 융해 후 72시간 째 생존률의 결과에서는 각각 60.5%, 32.8%로 유의성(p<0.1)이 검증되었다. 2. CB 농도별 생존률에 미치는 영향은 7.5 $\mu\textrm{g}$/$m\ell$의 처리군이 다른 처리군에 비하여 유의적으로 높았다(p<0.05). 정상 형태율 95%와 융해 후 생존률 73%로서 다른 농도에 비하여 65∼76%, 15∼57%보다 각각 높았다. 3. 7.5 $\mu\textrm{g}$/$m\ell$ 농도의 CB 전처리의 처리 시간에 따른 영향은 20분 처리하였을 때 정상적인 형태율은 81%로 다른 처리군(25∼69%)보다 높았고, 24시간 째 생존률의 결과로도 64%, 6∼56%로 유의적인 차이는 나타나지 않았다. 또한 원심 처리군과 비처리군에서도 CB를 20분으로 처리하였을 때 가장 좋은 결과를 나타내었으며, 원심 비처리군보다는 원심 처리군이 좀 더 높은 결과를 보여 주었다.

• 대한치과교정학회지
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• 제28권6호
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• pp.915-926
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• 1998

Cytoskeleton은 세포핵과 세포외 기질을 연결하고 있어서 기질에 가해지는 물리적 힘에 의해 cytoskeletal change가 유도되고 이에 의해 세포의 개조활성이 영향을 받는다고 생각되어 왔다. 본 연구는 골모세포 활성에 대한cytoskeletal change의 역할을 규명하기 위한 것으로서, 신생 백서로부터 조골세포양 세포를 분리, 배양하고 네가지 농도의 cytochalasin B(CB) 또는 colchicine(COL)을 3시간 처리하였다. 다시 배양액을 교환하고 24시간 동안 배양하여 prostaglandin $E_2\;(PGE_2)$, interleukin-6(IL-6), tumor necrosis factor-$\alpha$(TNF-$\alpha$) 및 matrix metalloproteinase-1 (MMP-1) 생산을 측정하고 통계적으로 비교하였으며 cytoskeletal protein actin 변화를 관찰하기위하여 면역형광염색하고 형광현미경으로 관찰하여 다음과 같은 결과를 얻었다: 1. CB 처리군에서 $PGE_2$ 생산이 증가되는 경향을 보였고 COL 처리군에서는 약물농도에 비례하여 증가하였다. 2. IL-6 생산은 CB농도 1.0 ${\mu}g/ml$일때를 제외하고 증가되었다. 3. TNF-$\alpha$도 CB 농도가 1.0 ${\mu}g/ml$ 일때를 제외하고 증가하였다. 4. MMP-1 생산은 CB 처리군에서 감소하는 경향을 보이고 COL 처리군에서는 변화되지 않았다. 5. CB처리군에서는 cytoskeletal actin stress fibers가 사라지고 세포모양이 둥글어지는 경향을 보였다. 이상의 결과로 미루어 보아 cytoskeletal rearrangement는 골모세포유사세포의 활성, 특히 $PGE_2$, IL-6, 및 TNF-$\alpha$같은 paracrine/autocrine factor의 생산과 관련있는 것으로 보인다.

• Bulletin of the Korean Chemical Society
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• 제30권6호
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• pp.1337-1340
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• 2009

Electrical properties of a fluorinated carbon black (CB)-filled high-density polyethylene (HDPE) polymeric switch were investigated as a function of fluorination pressure at 0.1 ~ 0.4 MPa. From the FT-IR results, the absorption spectra of the fluorinated CB show an absorption band at 1400 ~ 1000 $cm^{-1}\;for\;{\nu}_{C-F}$ and the peak intensity increased with increasing fluorination pressure. Also, the analysis of XPS spectra of the fluorinated CB indicated that fluorine content increased with increasing fluorination pressure. Meanwhile, the surface free energy of the fluorinated CB decreased with increasing fluorination pressure. Consequently, the increase of fluorine contents of CB made a disappearance of negative temperature coefficient (NTC) behavior of the polymeric switch, which was probably due to the reduction of CB reaggregation after melting point of the HDPE, resulted from the decreasing of London dispersive component of the surface free energy for CB particles.

• 서비스연구
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• 제10권4호
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• pp.71-88
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• 2020

CB(전환사채)는 주식전환권을 행사한 이후부터는 채권이 아닌 주식으로 변한다는 점에서 채권과 주식의 성격을 갖고 있는 메자닌 증권이다. 본 연구는 투자자 입장에서 CB의 투자효율성 정도를 실증규명하고 효율적인 투자방안을 제시하는 것이 연구목적이다. 연구방법은 CB종목별로 표면이자율, 만기이자율, 채권만기일, 전환가격, 전환청구일 등을 조사한 후, 전환청구일 이후 발행회사의 일별 주가변동과 연결하여 CB에 대한 투자의 효율성과 CB의 주식전환효과가 어느 정도인지를 계량적으로 파악하고자 하였다. 연구 결과, 전환가격초과일수비율이 전환 가능한 날짜의 1/4 정도에 불과하여 투자효율성은 낮은 것으로 분석되었다. 전환일수익률은 평균 -6.3%, 만기일수익률은 평균 -5.2%여서 평균적으로 minus 수익률을 보여 투자자 기대와 다르게 산출되었다. 전환일수익률이 minus인 종목수가 plus인 종목수보다 2.4배 많았으며, 만기일수익률이 minus인 종목수가 plus인 종목수보다 3.7배 많아서 CB의 주식전환 기대수익률은 낮은 것으로 분석되었다. 연구기여도는 CB의 기대수익률이 높지 않다는 문제점을 도출하였고, 투자자 입장에서 CB를 매입할 때 유의사항을 정립한 데 있다.

• Journal of Microbiology and Biotechnology
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• 제32권4호
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• pp.514-521
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• 2022

We report the effect of pH on the supramolecular complexation of two biothiols, viz., homocysteine (Hcy) and cysteine (Cys), with cucurbit[7]uril (CB[7]). Under basic pH conditions, Cys did not complex with CB[7], whereas Hcy efficiently complexed with CB[7], as confirmed by ¹H NMR spectroscopy and Ellman's reagent (5,5'-dithio-bis(2-nitrobenzoic acid), DTNB) assay. ¹H NMR and Raman spectroscopic studies revealed that, in the absence of CB[7], Hcy auto-oxidized slowly (~36 h) to homocystine (HSSH) under basic pH conditions. However, the rate of Hcy oxidation increased by up to 150 fold in the presence of CB[7], as suggested by the DTNB assay. Thus, supramolecular complexation under basic pH conditions led to the formation of a HSSH-CB[7] complex, and not Hcy-CB[7]. The results indicate that Hcy is rapidly oxidized to HSSH under the catalysis of CB[7], which acts as a reaction chamber, in basic pH conditions. Our studies suggest that Hcy concentration, a risk factor for cardiovascular disease, can be selectively and more easily quantified by supramolecular complexation with CB [7].