• 제목/요약/키워드: ${\alpha}$-Elimination

검색결과 87건 처리시간 0.021초

Histologic Characteristics and Mechanical Properties of Bovine Pericardium Treated with Decellularization and ${\alpha}$-Galactosidase: A Comparative Study

  • Min, Byoung-Ju;Kim, Yong Jin;Choi, Jae-Woong;Choi, Sun Young;Kim, Soo Hwan;Lim, Hong-Gook
    • Journal of Chest Surgery
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    • 제45권6호
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    • pp.368-379
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    • 2012
  • Background: Bioprostheses for cardiovascular surgery have limitations in their use following as calicification. ${\alpha}$-galactosidase epitope is known as a stimulant of immune response and then shows a progressing calcification. The objective of this study was to evaluate histologic characteristics and mechanical properties of decellularization and treated with ${\alpha}$-galactosidase. Materials and Methods: Bovine pericardial tissues were allocated into three groups: fixation only with glutaraldehyde, decellularization with sodium dodesyl sulfate and decellularization plus treatment with ${\alpha}$-galactosidase. We confirmed immunohistological characteristics and mechanical properties as fatigue test, permeability test, compliance test, tensile strength (strain) test and thermal stability test. Results: Decellularization and elimination of ${\alpha}$-gal were confirmed through immunohistologic findings. Decellularization had decreased mechanical properties compared to fixation only group in permeability (before fatigue test p=0.02, after fatigue test p=0.034), compliance (after fatigue test p=0.041), and tensile strength test (p=0.00). The group of decellularization plus treatment with ${\alpha}$-galactosidase had less desirable mechanical properties than the group of decellularization in concerns of permeability (before fatigue test p=0.043) and strain test (p=0.001). Conclusion: Favorable decellularization and elimination of ${\alpha}$-gal were obtained in this study through immunohistologic findings. However, those treatment including decellularization and elimination of ${\alpha}$-gal implied the decreased mechanical properties in specific ways. We need more study to complete appropriate bioprosthesis with decellularization and elimination of ${\alpha}$-gal including favorable mechanical properties too.

인삼 extract중의 $\alpha$-pyrrolidone검정 (Determination of $\alpha$--pyrrolidone in panax ginseng Extracts)

  • 서정상
    • 약학회지
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    • 제13권4호
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    • pp.111-120
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    • 1969
  • The determination of $\alpha$-pyrrolidone in ginseng extract by gas liquid chromatography (GLC) was established. $\alpha$-Pyrrolidone in extract was tentatively identified by comparison of the relative retention time of sample peak with those of reference compound and coinjection noted peak enhancement. The .alpha.-pyrrolidone peak elimination was demonstrated by formation of oxime when treated with excess of NH$_{2}$OH ${\cdot}$ HCl and NaOH, allowed to stand at room temperature for 5 minute. The elimination was also observed when samples were treated by the same procedure. The above method was proved to be useful for the determination of $\alpha$-pyrrolidone in ginseng extract and in ginseng extract mixed with 51 plant extracts.

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Photochemistry of $\alpha$, $\alpha$-Dihalovalerophenones

  • Cho, Sungsu;Park, Bong Ser
    • Journal of Photoscience
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    • 제11권2호
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    • pp.75-76
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    • 2004
  • ${\alpha}$,${\alpha}$-Dibromovalerophenone and ${\alpha}$,${\alpha}$-dichlorovalerophenone were prepared and their photochemical behaviors were investigated. The former gives C-Br cleavage products and the latter gives mainly the Yang photocyclization products upon irradiation. The reactivity of the chlorine substituted ketone turned out to be quite different from that of ${\alpha}$,${\alpha}$-difluorovalerophenone which gives both the cyclization and elimination products from the 1,4-biradical intermediate.

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Theoretical Studies on Gas-Phase Reactions of Negative Ions with Alkyl Nitrites

  • 박형연;김찬경;이본수;이해황;이익춘
    • Bulletin of the Korean Chemical Society
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    • 제21권8호
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    • pp.823-827
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    • 2000
  • Gas-Phase reactions of methyl and ethyl nitrites with anionic nucleophiles of SH-, F- and OH- are investigated theoretically at the MP2/6-311+G* level. The SN2 processes are all highly exothermic and proceed with a typ-icaI double-weIl reaction coordinate profile. The elimination reactions of methyl nitrite with SH- and F- are double-well energy surface processes,with stabilizedproduct complexes of NO-...H2S and NO-...HF, pro-ceeding by an E1 cb-like E2 mechanism. The $\beta-elimination$ of ethyl nitrite is an E2 type process. The $\alpha-elimi-nation$ reactions of methyl and ethyl nitrites with OH- have triple-well energy profiles of Elcb pathway with an $\alpha-carbanion$ intermediate which is stabilized bythe vicinal $nc\alpha-{\sigma}*o-N$ charge transfer interactions. CompIex-ation ofmethyl carbanion with HF seems to provide a stable intermediate within a triple-well energy profile of El cb channel in the reaction of F- with methyl nitrite.

히단토인 유도체 형성에 있어서 $\alpha$-Diethaylaminoacetophenone의 탈이반응 (Elimination Reaction of $\alpha$-Diethaylaminoacetophenone in the Formation of Hydantoin Derivatives)

  • 권순경
    • 약학회지
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    • 제22권4호
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    • pp.215-218
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    • 1978
  • It is known that hydantoin derivative can be synthesized according to the method of Bucherer-Bergs, which employs the interaction of the carbonyl compounds with potassium cyanide and ammonium carbonate in dilute alcohol solution. In a converting study of .alpha.-dietylaminoacetophenone with KCN and ($NH_{4})_{2}CO_{3}$ to hydantoin, the attempted 5-diethylaminomethyl-5-phenylhydantoin was not formed. In this reaction diethylaminomethly group was unexpectedly eliminated and 5-phenylhydantoin was obtained, instead of the anticipated compound.

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Reaction Intermediate of Organic Sulfur Compound Ⅰ. Elimination Mechanism of Sulfonyl Chloride

  • Tae-Seop Uhn;Jong-Pal Lee;Hyun-Seok Park;Hyung-Tae Kim;Zoon-Ha Ryu
    • Bulletin of the Korean Chemical Society
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    • 제11권1호
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    • pp.60-64
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    • 1990
  • The reactions of alkanesulfonyl chlorides with pyridines in the presence of various solvents have been studied by means of kinetic method. Alkanesulfonyl chlorides bearing ${\alpha}$-hydrogen with the normal attack of pyridine is found to be at the ${\alpha}$-hydrogen with elimination to form the sulfene intermediate evidently. From the mass spectra by the reaction of ethanesulfonyl chloride with 3-picoline in the presence of methanol-$d_1$, it has shown that the reaction has a witness favorable to the slulfene intermediate.

Galactomannan 이용에 관한 연구 : Affinity Chromatography에 의한 지렁이 유래 /alpha-Galactosidase의 정제 및 응용법 (Purification and Application of Earthworm /alpha-Galactosidase by Affinity Chromatography)

  • 박귀근;정규훈;소림수행
    • 한국미생물·생명공학회지
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    • 제27권4호
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    • pp.298-303
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    • 1999
  • An $\alpha$-D-galactosidase ($\alpha$-D-galactoside galactohydrolase, EC 3. 2. 1. 22) from earthworm was purified by affinity chromatography using N-$\varepsilon$-aminocaproyl-$\alpha$-D-galactopyranosylamine coupled to sepharose and its properties were examined. The specific activity of the purified enzyme, tested with p-nitrophenyl-$\alpha$-D-galactopyranoside as substrate, was 314 units/mg protein, representing an 122-fold purification of the original crude extract. The final preparation obtained from by Sephadex G-25 chromatography showed a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight was determined to be 48,000 by SDS-polyacrylamide gel electrophoresis. The purified galactosidase was showed maximum activity at pH 4.5 and 4$0^{\circ}C$, and was stable in the pH and temperature ranges from 4.0 to 5.5 and 30 to 5$0^{\circ}C$, respectively. The enzyme activity was inhibited by Zn2+, Hg2+ and Co2+. When the purified $\alpha$-galactosidase treated to guar gum for 6 hour, gel-promoting property was increased. It was clear that enzymatic elimination of galactose from guar gum by purified $\alpha$-galactosidase would lead to a significant increase in gelation ability.

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비만변증 설문지에 대한 신뢰도 분석 (A reliability analysis of syndrome differentiation questionnaire for obesity)

  • 강병갑;문진석;최선미
    • 한국한의학연구원논문집
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    • 제13권1호통권19호
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    • pp.109-114
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    • 2007
  • The high position condition 10 escape which the obesity person appeals. Obesity Pattern-Identification question it will yell and 243 subjects which to the obesity in the patient of 517 subjects which draw up correspond. (longitude obesity 153 person, altitude obesity 90 person) against it analyzes. In order to analyze the reliability of the items which diagnose each Pattern-Identification it used Cronbach alpha coefficient and escape it did the alpha of each item. Alpha value of each Pattern-Identification than appears more highly the item which it will be able to consider an elimination in the item which decreases a reliability. In that phlegm-retention syndrome is bigger alpha coefficient 0.784 than 'meal quantity is few'(0.787) a possibility of seeing in the item which decreases a reliability to the place where it diagnoses it puts in phlegm-retention syndrome.

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