• Title/Summary/Keyword: NTA

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Dehydropolycondensation of Aminophenols under the Catalytic Action of Metallic Chelate Compounds (II) Effects of the Ligands, Structures of the Mixed Complexes, and Side Reactions (金屬킬레이트 化合物의 觸媒作用에 依한 Aminophenol 類의 酸化的 重縮合反應 (Ⅱ) Ligands 種의 效果, 混合錯物의 構造및 副反應)

  • Choi, Kyu-Suck
    • Journal of the Korean Chemical Society
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    • v.12 no.3
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    • pp.121-127
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    • 1968
  • In the oligomerization of p-aminophenol under the catalytic action of the metallic complexes, the effects of the ligands are studied. When the initial velocity of $O_2$ uptake at pH 8 using Fe(Ⅲ) as the central metal and N-hydroxylethylethylenediaminetriacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), 1,2-cyclohexanediaminetetraacetic acid(CyDTA) as the ligands respectively are compared, the velocities are as the following order: HEDTA > EDTA > DTPA > CyDTA. Further when the effect of the ligands, nitrilotriacetic acid (NTA), HEDTA, EDTA, and DTPA, on the yields of oligomers are compared, the result shows as the following order: NTA > HEDTA > EDTA > DTPA. These are nearly reverse order of the stability constants of the complexes. In order to determine the composition of the mixed complexes at the initial step, the method of continuous variation is used, and it is found that the composition ratio of Fe-EDTA complex to monomer in the mixed complexes is one at pH 5-8 range. It is also found that at pH 9 or in the more alkaline range, side reactions occur to form water soluble dimer of quinone type and the catalytic action of the metallic complex markedly decreases on account of the hydrolysis of the central metal by the $OH^-$ ion.

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An Experimental Phonetic Study of Rhythm in Standard Korean (한국어의 리듬에 관한 실험음성학적 연구)

  • Lee Hyeon-Bok
    • MALSORI
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    • no.25_26
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    • pp.52-64
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    • 1993
  • This paper aims to explore the rhythmic phenomena of standard Korean by an experimental phonetic method. A total of 16 informants taking part in this experiment were divided into four groups : old males(OM) and old females(OF) in their fifties and young males(YM) and young females(YF) in their twenties. The informants were asked to read speech data consisting of two rhythmic units, each of which began with a stressed syllable with a long wowel. Starting with the frame / 'ma:1 'ma:nta /, the first rhythmic unit was expanded up to five syllables in all while keeping the second rhythmic unit constant with a view to investigate the pattern of increase in the interstress time interval. The results of this study are as follows: 1. There is a considerable difference between yen and old generations with respect to the duration of interstress interval . The young generation tends to speak faster than the old generation. This observation is supported by difference in the interstress intervals as exhibited by OM(389.66), OF(473), YM(275.55), YF(285.83) in the test frame '말 많다' ['ma:1 'ma:nta]. 2. Young and old generations showed a different tendency in the increase rate of duration between mono-syllables and polysyllables. In other words, the rhythm of young generation shows the tendency of syllable-timed language whereas that of old generation clearly leans towards the stressed-timed language.

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Carbon-13 and Vanadium-51 Nuclear Magnetic Resonance Studies of Vanadium(v)-Aminopolycarboxylic Acids (Ⅰ) (바나듐 (v)-아미노폴리카르본산 착물의 탄소-13 및 바나듐-51 핵자기공명연구 (제1보))

  • Man-Ho Lee;Tae-Sub O
    • Journal of the Korean Chemical Society
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    • v.27 no.2
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    • pp.117-126
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    • 1983
  • $^13C$ and $^51V$ NMR spectroscopy have been used to study the solution structures of the vanadium (v) complexes formed by ethylenediaminetetraacetic acid (EDTA), trans-cyclohexanediaminetetraacetic acid (CDTA), 1,2-propylenediaminetetraacetic acid (PDTA), ethylenediaminediacetic acid (EDDA), 2-hydroxyethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentacetic acid (DPTA), and nitrilotriacetic acid (NTA). All of the complexes probably have octahedral structures containiing cis-$VO_2$ core. The coordination of hydroxylethyl group is found to be less favored than that of acetate group. EDDA forms two isomers, ${\alpha}$-cis and ${\beta}$-cis. PDTA also forms two structural isomers due to the methyl group in the ligand.

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Unfolded Histidine-Tagged Protein is Immobilized to Nitrilotriacetic Acid-Nickel Beads, But Not the Nickel-Coated Glass Slide

  • Cho Min-Ho;Ahn Sun-Young;Park Heon-Yong
    • Genomics & Informatics
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    • v.4 no.3
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    • pp.133-136
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    • 2006
  • The adsorption of proteins on the surface of glass slides is essential for construction of protein chips. Previously, we prepared a nickel-coated plate by the spin-coating method for immobilization of His-tagged proteins. In order to know whether the structural factor is responsible for the immobilization of His-tagged proteins to the nickel-coated glass slide, we executed a series of experiments. First we purified a His-tagged protein after expressing the vector in E. coli BL21 (DE3). Then we obtained the unfolding curve for the His-tagged protein by using guanidine hydrochloride. Fractions unfolded were monitored by internal fluorescence spectroscopy. The ${\Delta}G_{H20}$ for unfolding was $2.27kcal/mol{/pm}0.52$. Then we tested if unfolded His-tagged proteins can be adsorbed to the nickel-coated plate, comparing with $Ni^{2+}-NTA$ (nitrilotriacetic acid) beads. Whereas unfolded His-tagged proteins were adsorbed to $Ni^{2+}-NTA$ beads, they did not bind to the nickel-coated plate. In conclusion, a structural factor is likely to be an important factor for constructing the protein chips, when His-tagged proteins will immobilize to the nickel-coated slides.

Return of Self-identity and Story of the Other which disappeared in Advaita Vedanta (아드와이따 베단따의 자아정체성 귀환과 사라진 타자의 이야기)

  • Park, Hyo-yeop
    • Journal of Korean Philosophical Society
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    • v.126
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    • pp.109-132
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    • 2013
  • The most important vocabulary in Advaita $Ved{\bar{a}}nta$, which is anthropology and soteriology on the self, is of course '${\bar{a}}tman$' or 'the self', to which '$an{\bar{a}}tman$' or 'the other' is in opposition. As $Ved{\bar{a}}ntic$ system revolves around the concept ${\bar{a}}tman$, it can be compared favorably with 'final vocabulary' of Richard Rorty. Moreover, $Ved{\bar{a}}ntic$ system can be termed as 'a return of self-identity', in which a process of returning is from a deceived self to the true and original self. After all, story of '$an{\bar{a}}tman$' or 'the other' in $Ved{\bar{a}}nta$ seems to have no significance at all. However, discourse about the other can also lead a something fruitful. There are such doctrines in $Ved{\bar{a}}nta$ that support a procedure of self-realization not according to the Hegelian dialectic but to the transposition and continuous antagonism between the self and the other, as a special meaning of viveka (discrimination) that fixes a boundary between the self and the other, a destruction of falsehood that is more important than establishment of truthfulness, a transposition of the true and the false before and after self-realization. Thus the other is not disappeared but only hidden, even after accomplishing its own methodological role, and the same is with discourse about the other. To revive forgotten vocabulary in $Ved{\bar{a}}nta$ is an attempt to reconstruct devaluated story by means of shifting the pivot of discourse from the self to the other. The essential thing in this attempt may be to revive the conceptions of 'effort' that is intently concealed and of 'self-inquiry' that has lost its true meaning. Out of these, a systematic and continuous self-inquiry, consists in having a scenario on the question 'Who am I?' and utilizing that scenario by experience without interruption. A work of reconstructing the lost narratives in $Ved{\bar{a}}nta$ can be feasible only when the history of self-inquiry is redescribed in the system itself, provided that object of inquiry is not 'a self as the self' but 'a self as the other'.

In vitro Antioxidant Effects of Sarijang (사리장의 항산화 효과)

  • Seo, Bo-Young;Choi, Mi-Joo;Choi, Eun-A;Park, Eunju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.4
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    • pp.618-623
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    • 2014
  • Sarijang, a soy sauce made from fermented black soybean (Rhynchosia nulubilis), sulfur fed duck, dried bark of Ulmus davidiana, Allium sativum, and bamboo salt, has been demonstrated to exert anti-inflammatory and anti-tumor activities. However, the antioxidant properties of Sarijang have not yet been elucidated. In this study, the antioxidant effects of Sarijang were investigated by determining total phenolic content (TPC), DPPH radical scavenging activity (DPPH RSA), total radical trapping antioxidant potential (TRAP), oxygen radical absorbance capacity (ORAC), and cellular antioxidant capacity (CAC). The inhibitory effects of Sarijang on oxidative stress-induced DNA damage (200 ${\mu}M$ $H_2O_2$, 250 ${\mu}M$ Fe-NTA, and 200 ${\mu}M$ HNE) in human leukocytes were evaluated by comet assay. The TPC of Sarijang was $1.04{\pm}0.01$ mg GAE/mL. DPPH RSA, TRAP, and ORAC values of Sarijang increased in a dose-dependent manner. The $IC_{50}$ for DPPH RSA of Sarijang was $11.2{\pm}0.3$ mg/mL, whereas $IC_{50}$ of TRAP was $209.5{\pm}2.0$ mg/mL. 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress and oxidative stress-induced DNA damage in HepG2 cells were effectively abrogated by all tested concentrations of Sarijang (1~100 ${\mu}g/mL$). These results suggest that Sarijang has antioxidative activity and protective effects against oxidative DNA damage.

The development of murine recombinant single-chain variable domain fragment (ScFv) specific to acute non-lymphocytic leukemia (ANLL) cell line HL60 (인간의 급성 비임파성 백혈암세포(HL60)의 표면항원에 결합하는 재조합 single-chain Fv (ScFv)의 개발)

  • Kim, Cheol Hong;Han, Seung Hee;Kim, Hyeong Min;Han, Jae Yong;Lim, Myeong Woon;Kim, Jin-Kyoo
    • Korean Journal of Microbiology
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    • v.51 no.2
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    • pp.115-125
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    • 2015
  • A monoclonal antibody AP64 IgM binds to human acute nonlymphocytic leukemia (ANLL) cell line HL60 and also cross-reacts with the homologous antigen in a rat ANLL cell. This antibody mediated by complement, has leukemia a suppression effect. In this study, we generated a recombinant single-chain variable domain fragment (ScFv) which were derived from $V_H$ and $V_L$ cDNA of AP64 IgM-secreting hybridoma by RT-PCR. The two variable regions were joined with a single 15 amino acid linker $(G_4S)_3$. This recombinant ScFv was expressed as a single polypeptide chain from Escherichia coli BMH 71-18. The recombinant ScFv was purified by applying the periplasmic extract to $Ni^+$-NTA-agarose affinity column and detected with westernblot. The purified recombinant ScFv recognized a surface antigen (about 30 kDa) of HL60 cell line which is the same antigen detected by parental AP64 IgM. But the affinity of ScFv for a surface antigen of HL60 was lower than that of the parental AP64 IgM, which needs to be further improved. Overall, the recombinant ScFv specific to HL60 might be a useful bioreagent for either diagnostic or therapeutic purposes.

Studies on Interaction of Essential Metal Ions with Bioactive Ligands

  • Tewari, Brij Bhushan
    • Bulletin of the Korean Chemical Society
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    • v.25 no.6
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    • pp.809-812
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    • 2004
  • Complexation reactions of nitrilotriacetate (NTA) and penicillamine with $Cu^{2+}$ and $Co^{2+}$ have been studied in solution phase using paper electrophoresis technique. The stability constants of the complexes Cu(II)-nitrilotriacetate-penicillamine and Co(II)-nitrilotriacetate-penicillamine have been found to be $6.64{\pm}0.03\;and\;5.86{\pm}0.05$ (logarithm stability constant values), respectively at 35$^{\circ}C$ and ionic strength 0.1 M.

$^{13}C$ NMR Studies of the Chelate Ring Opening-Closing Process in (Nitrilotriacetato)vanadate(V) dioxovandate(V) Ion

  • Lee, Man-Ho;Schaumburg, Kjeld
    • Bulletin of the Korean Chemical Society
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    • v.11 no.5
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    • pp.399-402
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    • 1990
  • Activation parameters of the exchange between two types of glycinate groups in (nitrilotriacetato)dioxovanadate(V) ion, $[VO_2(NTA)]^{2-}$, have been determined as the results of $^{13}C$ NMR measurements over a range of temperatures between 277 and 306$^{\circ}K$. The exchange mechanism is proposed on the basis of the chelate ring opening-closing process, assuming rupture of the metal-oxygen (glycinate) bond trans to V = O bond to give a five-coordinated intermediate.