• Title/Summary/Keyword: cross-reaction

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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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    • v.24 no.5
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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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The Effects of Cross-Section Openings on the Chlorination Reaction Rate of ZIRLO Cladding Hulls (단면 개방이 ZIRLO 피복관의 염소화 반응 속도에 미치는 영향)

  • Jeon, Min Ku;Choi, Yong Taek;Lee, Chang Hwa;Kang, Deok Yoon;Hur, Jin-Mok;Ahn, Do-Hee
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.13 no.3
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    • pp.211-218
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    • 2015
  • The reaction rates of ZIRLO cladding hulls with cross-section openings were investigated using a thermo-gravimetric analysis system in order to identify whether selective recovery of Zr from oxidized cladding hulls is possible. The experimental results showed that an oxidized ZIRLO cladding hull was not reactive with chlorine gas at 400℃. However, providing fresh cross-sections on one or both ends of the ZIRLO hulls enabled a chlorination reaction. This reaction was completed after 8 hours; a 14% increase on the 7 hours seen with a bare ZIRLO cladding hull. The Sharp-Hancock plot analysis results revealed that the contracting volume model is the best for describing the reaction between the cross-section opened ZIRLO hulls and chlorine gas under the condition of this work. It was concluded that the chlorination process can be employed for oxidized ZIRLO cladding hulls by providing cross-section openings.

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

  • Maeta, Eri;Ishihara, Kazuhiko
    • Biomaterials and Biomechanics in Bioengineering
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    • v.1 no.3
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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.

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

  • Han, Young Taek
    • YAKHAK HOEJI
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    • v.59 no.2
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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.

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

  • Kim, Hwa Sik;Park, Moo Seo
    • Korean Journal of Veterinary Research
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    • v.14 no.1
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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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Physicochemical Properties of Cross-linked Apios Starch (가교결합 아피오스 전분의 이화학적 특성)

  • Park, Mi Hye;Kim, Meera
    • Journal of the East Asian Society of Dietary Life
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    • v.24 no.3
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    • pp.400-406
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    • 2014
  • Apios (Apios americana Medikus) belongs to Leguminosae and is called 'American groundnut', 'Potato bean', and 'wild bean'. Apios is native to the Northern United States but is not widely distributed in Korea. In this study, cross-linked apios starch was prepared by reaction with epichlorohydrin, followed by characterization. FT-IR spectroscopy confirmed the degree of cross-linking of apios starch. X-ray diffraction patterns of native apios showed typical 'A' type as peaks at 15.1, 17.1, 17.9 and $23.2^{\circ}$, and cross-linking did not affect relative crystallinity and X-ray diffraction patterns of the starch. Scanning electron micrographs showed that apios starch granules were smooth with a globular shape, and there was little damage to starch granules after cross-linking. The lightness value of cross-linked apios starch was lower than that of native apios starch, whereas the redness value was not significantly different between cross-linked apios starch and native apios starch. Blue value showed that cross-linking of starch did not affect the iodine reaction of starch.

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

  • Yoon, Jungran
    • Journal of the Korean Society of Radiology
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    • v.10 no.5
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    • pp.337-341
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    • 2016
  • We measured the neutron capture cross-section of natural Sm(n,${\gamma}$) reaction in the energy regions from 0.003 to 10 eV. The 46-MeV electron linear accelerator of Research Reactor Institute, Kyoto University was used for generating a continuous neutron source. The neutron time-of-flight method was adopted for energy measurement. An assembly of BGO($Bi_4Ge_3O_{12}$) scintillators composed of 12 pieces of BGO crystals measured prompt gamma rays from Sm(n,${\gamma}$) reaction. The BGO assembly was located at a distance of $12.7{\pm}0.02m$ from the neutron source. In order to determine the neutron flux impinging on the Sm, the $^{10}B(n,{\alpha}{\gamma})^7Li$ standard cross-section were used. Natural Sm(n,${\gamma}$) reaction measurement result of the neutron capture cross-section was compared with the results of evaluation of the BROND-2.2 and the previous experimental data of J. C. Chou and V. N. Kononov.

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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    • v.34 no.11
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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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    • v.33 no.2
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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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    • v.16 no.2
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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.