• 제목/요약/키워드: cross-reaction

검색결과 949건 처리시간 0.037초

DNA Structural Perturbation Induced by the CPI-Derived DNA Interstrand Cross-linker : Molecular Mechanisms for the Sequence Specific Recognition

  • Park, Hyun-Ju
    • Archives of Pharmacal Research
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    • 제24권5호
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    • pp.455-465
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    • 2001
  • The highly potent cytotoxic DNA-DNA cross-linker consists of two cyclopropa[c]pyrrolo[3,4-3]indol-4(5H)-ones insoles [(+)-CPI-I] joined by a bisamido pyrrole (abbreviated to "Pyrrole"). The Pyrrole is a synthetic analog of Bizelesin, which is currently in phase II clinical trials due to its excellent in vivo antitumor activity. The Pyrrole has 10 times more potent cytotoxicity than Bizelesin and mostly form DNA-DNA interstrand cross-links through the N3 of adenines spaced 7 bp apart. The Pyrrole requires a centrally positioned GC base pair for high cross-linking reactivity (i.e., $5^1$-T$AT_2$A*-$3^1$), while Bizelesin prefers purely AT-rich sequences (i.e., $5^1$-T$AT_4$A*-$3^1$, where /(equation omitted) represents the cross-strand adenine alkylation and A* represents an adenine alkylation) (Park et al., 1996). In this study, the high-field $^1$H-NMR and rMD studies are conducted on the 1 1-mer DNA duplex adduct of the Pyrrole where the 5′(equation omitted)TAGTTA*-3′sequence is cross-linked by the drug. A severe structural perturbation is observed in the intervening sequences of cross-linking site, while a normal B-DNA structure is maintained in the region next to the drug-modified adenines. Based upon these observations, we propose that the interplay between the bisamido pyrrole unit of the drug and central C/C base pair (hydrogen-bonding interactions) is involved in the process of cross-linking reaction, and sequence specificity is the outcome of those interactions. This study suggests a mechanism for the sequence specific cross-linking reaction of the Pyrrole, and provides a further insight to develop new DNA sequence selective and distortive cross-linking agents.

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단면 개방이 ZIRLO 피복관의 염소화 반응 속도에 미치는 영향 (The Effects of Cross-Section Openings on the Chlorination Reaction Rate of ZIRLO Cladding Hulls)

  • 전민구;최용택;이창화;강덕윤;허진목;안도희
    • 방사성폐기물학회지
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    • 제13권3호
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    • pp.211-218
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    • 2015
  • 본 연구에서는 산화된 피복관으로부터 염소화 공정을 통해 Zr을 선택적으로 회수하기 위한 연구의 일환으로, 단면이 개방된 ZIRLO 피복관의 염소화 반응 속도식을 열중량분석기를 이용하여 분석하였다. 실험을 통해 산화된 ZIRLO 피복관은 400도 염소화 조건에서 염소 기체와 반응하지 않는 것으로 확인되었다. 하지만 피복관 한쪽 혹은 양쪽 끝의 새로운 단면이 개방될 경우 ZIRLO의 염소화 반응이 가능함을 확인하였고 반응을 완료하기까지 8 시간이 소요되었다. 이는 반응 완료까지 7 시간이 소요된 산화되지 않은 피복관에 비하여 반응시간이 14% 증가한 것이다. Sharp-Hancock 식을 이용하여 단면이 개방된 ZIRLO 피복관과 염소 기체의 반응을 모사하기 위한 구조함수를 도출하였으며, 부피축소 모델이 본 연구 조건에서 가장 적합한 구조 함수로 확인되었다. 또한, 본 연구를 통해 ZIRLO 피복관의 표면이 산화되어 있는 조건에서도 단면노출을 통해 염소화 공정에 적용이 가능함을 확인하였다.

Cross-linkable and water-soluble phospholipid polymer as artificial extracellular matrix

  • Maeta, Eri;Ishihara, Kazuhiko
    • Biomaterials and Biomechanics in Bioengineering
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    • 제1권3호
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    • pp.163-174
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    • 2014
  • The objective of this study is to prepare an artificial extracellular matrix (ECM) for cell culture by using polymer hydrogels. The polymer used is a cytocompatible water-soluble phospholipid polymer: poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-n-butyl methacrylate-p-nitrophenyloxycarbonyl poly(ethylene oxide) methacrylate (MEONP)] (PMBN). The hydrogels are prepared using a cross-linking reaction between PMBN and diamine compounds, which can easily react to the MEONP moiety under mild conditions. The most favorable diamine is the bis(3-aminopropyl) poly(ethylene oxide) (APEO). The effects of cross-linking density and the chemical structure of cross-linking molecules on the mechanical properties of the hydrogel are evaluated. The storage modulus of the hydrogel is tailored by tuning the PMBN concentration and the MEONP/amino group ratio. The porous structure of the hydrogel networks depends not only on these parameters but also on the reaction temperature. We prepare a hydrogel with $40-50{\mu}m$ diameter pores and more than 90 wt% swelling. The permeation of proteins through the hydrogel increases dramatically with an increase in pore size. To induce cell adhesion, the cell-attaching oligopeptide, RGDS, is immobilized onto the hydrogel using MEONP residue. Bovine pulmonary artery endothelial cells (BPAECs) are cultured on the hydrogel matrix and are able to migrate into the artificial matrix. Hence, the RGDS-modified PMBN hydrogel matrix with cross-linked APEO functions as an artificial ECM for growing cells for applications in tissue engineering.

팔라듐 촉매하 결합반응을 이용한 플루비프로펜의 간결한 합성 (Concise Synthesis of Flurbiprofen via Palladium-Catalyzed Cross-Coupling Reactions)

  • 한영택
    • 약학회지
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    • 제59권2호
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    • pp.66-69
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    • 2015
  • A concise synthesis of flurbiprofen, a member of the non-steroidal anti-inflammatory 2-arylpropionic acids, has been accomplished. The key feature of this synthesis involves successive palladium-catalyzed cross coupling reactions. In particular, a 2-arylacylate intermediate, which easily converted to the key 2-arylpropionic acid scaffold, was afforded by a versatile palladium-catalyzed cross coupling reaction between diazopropanate and bisphenylboronic acid. This synthetic procedure would facilitate synthesis of the flurbiprofen and anti-inflammatory 2-arylpropionic acid derivatives.

우췌질증(牛膵蛭症)의 피내반응(皮內反應)에 관한 연구(硏究) (Studies on the Intradermal Reaction in Bovine Eurytremiasis)

  • 김화식;박무서
    • 대한수의학회지
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    • 제14권1호
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    • pp.59-71
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    • 1974
  • The studies were conducted on the allergic skin reaction of bovine eurytremiasis. In order to confirm the appearance of allergic skin reaction in this disease, a protein fraction of Eurytrema SPP(EPF) was extracted, and it's antigenicity was studied by means of intradermal reaction on the rabbits, goats and bovine. Rabbits used in this studies were divided into three groups: the first group was sensitized with EPF, the second group was sensitized with EPF, and the third group was served as control which is consisted with 5 non-sensitized and 2 saline injected rabbits. Three healthy native goats and bovine also used. Among these, 86 cases were eurytremiasis, 31 cases were fascioliasis and 71 cases non-infected. A protein fraction was also made from adult worm of Fasciola SPP(FPF) and tested the cross reaction between these two different fluke infestations. The results obtained were as follow: 1. Intradermal reaction was appeared in the infected cattle(bovine eurytremiasis) as well as in the EPF sensitized rabbits and goats. 2. In the EPF sensitized rabbits, the wheal of the intradermal reaction reacted the maximum size (increased wheal size of 5.0 to 9.0 mm) in 40 to 60 minutes and erythema in 60 minutes after intradermal injection of EPF antigen. In the EPF sensitized goats, the size of wheal reacted the maximum(increased wheal size of 5.5 to 8.0 mm) in 30 to 40 minutes, and then disappeared in 120 to 180 minutes after injection of EPF antgen. On the contrary, in the control groups of rabbits and goats, the wheal (7.0 mm) produced following antigen injection reached only to 7.5 to 8.5 mm. in 10 minutes without developing erythema, and then perished in 40 to 60 minutes after injection of EPF antigen. In the infected cattle, the wheal of the intradermal reaction reached the maximal sizes(increased wheal size of 4.0 to 11.0 mm) in 15 to 20 minutes and perished in 60 to 90 minutes after injection of EPF antigen. 3. It would be standardized that the positive reaction is above 4.0 mm, the negative below 2.0 mm and the suspective is 3.0 mm of the infected cattle. In the results of intradermal reaction, 87.2%(75 of 86 cases) was positive, 4.7%(4 of 86 cases) negative and 8.1% (7 of 86 cases) was suspective. However, in the non-infected control cattle, the wheal produced following injection disappeared in 30 to 40 minutes without increasing the wheal size in the most subjects or with incresing only to 1.0 to 2.0 mm in a few cattle. 4. In the results of intradermal reaction which were reciprocally tested in EPF sensitized rabbits by FPF antigen and in FPF sensitized. rabbits by EPF antigen, there were cross reacted. In the 31 cases if fascioliasis tested by EPF antigen, 11 cases were not specifically reacted with EPF antigen. Judging from the results of cross reaction in experimental rabbits and natural bovine fascioliasis, it would be expected when both EPF and EPF antigens are given intracutaneously on the same bovine patients of eurytremiasis or fascioliasis, the former antigen will produce the larger wheal in eurytremiasis, while the latter antigen will produce also the larger wheal in fascioliasis.

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가교결합 아피오스 전분의 이화학적 특성 (Physicochemical Properties of Cross-linked Apios Starch)

  • 박미혜;김미라
    • 동아시아식생활학회지
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    • 제24권3호
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    • pp.400-406
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    • 2014
  • 본 연구에서는 아피오스로부터 전분을 추출하여 epichlorohydrin으로 가교결합을 시킨 후 가교결합 아피오스 전분의 이화학적 특성을 분석하였다. 가교결합 아피오스 전분은 치환도가 증가함에 따라 몰가교화도가 0.1225에서 3.5124로 비례적으로 증가하였으며, FT-IR을 측정한 결과, CLAP-2%는 에테르 결합으로 인하여 $1,646cm^{-1}$$2,930cm^{-1}$에서 피크의 강도가 강해져 가교결합 반응이 이루어졌음을 확인할 수 있었다. 천연 아피오스 전분의 X-선 회절도는 $2{\theta}$=15.1, 17.1, 17.9, $23.2^{\circ}$에서 피크가 나타나는 전형적인 A형 전분 형태를 나타내었으며, 가교결합 아피오스 전분은 가교화에 의해 회절도와 상대결정화도에 큰 변화를 보이지 않아 무결정 영역에서 가교결합 반응이 일어난 것으로 추정되었다. 아피오스 전분 입자를 SEM으로 관찰한 결과, 전분 입자는 구형 또는 타원형 모양을 나타내었으며, 가교결합 아피오스 전분은 천연 아피오스 전분과 비교하였을 때 전체적인 형태에는 변화가 없는 것이 관찰되었다. 색도는 가교결합이 진행되면서 명도와 청색도가 변화하였으며, 청가는 천연 아피오스 전분과 가교결합 아피오스 전분 사이에 유의적인 차이가 나타나지 않았다.

연속에너지 중성자에 대한 천연 Sm의 중성자 포획단면적 측정 (Measurement of Energy Dependent Differential Neutron Capture Cross-section of Natural Sm by Using a Continuous Neutron Flux below)

  • 윤정란
    • 한국방사선학회논문지
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    • 제10권5호
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    • pp.337-341
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    • 2016
  • 중성자에너지 영역 0.003 eV에서 10 eV에 대해 천연 Sm의 Sm(n,${\gamma}$) 반응에 대한 중성자 포획단면적을 측정하였다. 교토대학교 원자로실험소의 46-MeV 전자선형가속기에서 발생되는 전자의 광핵반응에 의한 중성자를 사용하였고 TOF 방법으로 측정하였다. 사용한 검출기는 12개의 BGO($Bi_4Ge_3O_{12}$) 섬광체로 구성되었고 이 검출장치로 Sm(n,${\gamma}$) 반응으로부터 나오는 즉발감마선을 측정하였다. 검출장치는 중성자 생성 위치로부터 $12.7{\pm}0.02m$ 위치에 설치되었으며 $^{10}B(n,{\alpha}{\gamma})^7Li$ 반응을 이용해 Sm 시료에 입사되는 중성자 선속을 구하였다. 또한 중성자 선속의 변화를 확인하기 위해 $BF_3$ 검출기로 모니터링 하였다. Sm(n,${\gamma}$) 반응단면적 측정결과는 BROND 2.2에 의한 평가결과와 J. C. Chou 및 V. N. Kononov 의 측정값과 비교하였다.

The Influence of Collision Energy on the Reaction H+HS→H2+S

  • Liu, Yanlei;Zhai, Hongsheng;Zhu, Zunlue;Liu, Yufang
    • Bulletin of the Korean Chemical Society
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    • 제34권11호
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    • pp.3350-3356
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    • 2013
  • Quasi-classical trajectory calculations have been carried out for the reaction H+HS by using the newest triplet 3A" potential energy surface (PES). The effects of the collision energy and reagent initial rotational excitation are studied. The cross sections and thermal rate constants for the title reaction are calculated. The results indicate that the integral cross sections (ICSs) are sensitive to the collision energy and almost independent to the initial rotational states. The ro-vibrational distributions for the product $H_2$ at different collision energies are presented. The investigations on the vector correlations are also performed. It is found that the collision energies play a postive role on the forward scatter of the product molecules. There is a negative influence on both the alignment and orientation of the product angular momentum for low collision energy at low energy region. Whereas the influence of collision energy is not obvious at high energy region.

Quasi-classical Trajectory Calculation of the Chemical Reactions Ba+C6H5Br, m-C6H4CH3Br

  • Xia, Wenwen;Liu, Yonglu;Zhong, Haiyang;Yao, Li
    • Bulletin of the Korean Chemical Society
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    • 제33권2호
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    • pp.589-596
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    • 2012
  • In this paper, the reactive dynamics properties of the reactions Ba + $C_6H_5Br$ and Ba + m-$C_6H_4CH_3Br$ were studied by means of the quasi-classical trajectory method based on the London-Eyring-Polanyi-Sato potential energy surfaces. The vibrational distributions, reaction cross sections, rotational alignments of the products BaBr all were obtained. The peak values of the vibrational distributions are located at $\nu$ = 0 for the reactions Ba + $C_6H_5Br$ and Ba + m-$C_6H_4CH_3Br$ when the collision energies are 1.09 and 1.10 eV, respectively. The reaction cross sections increase with the increasing collision energy, which changes from 0.6 to 1.5 eV. The product rotational alignments deviate from -0.5 and firstly increase and then decrease while the collision energy is increasing, just like that of Heavy+Light-Light system.

Inhibition of Transglutaminase and Microbial Transglutaminase Activity by Garlic

  • Lee, Nam-Hyouck;Takeuchi, Atsuyoshi;Konno, Kunihiko
    • Food Science and Biotechnology
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    • 제16권2호
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    • pp.223-227
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    • 2007
  • Ground garlic inhibited the cross-linking reaction of myosin and incorporation of monodansylcadaverine (MDC) in salted Alaska pollack surimi catalyzed by transglutaminase (TGase). The component responsible for the inhibition was a thermostable, low molecular weight compound. The component also inhibited microbial transglutaminase (MTGase). The inhibition by garlic was reversibly recovered upon addition of 2-mercaptoethanol. The inhibitory component was therefore hypothesized to contain sulfhydryl groups within its structure. Alliin itself did not inhibit the cross-linking reaction. However, the addition of alliin together with garlic increased the inhibition. This result suggested that compounds derived from alliin was responsible for the inhibition of TGase activity.