• 제목/요약/키워드: beta-ray

검색결과 619건 처리시간 0.026초

푸로세미드의 안정성 및 생체내 이용율에 미치는 ${\beta}-$시클로덱스트린의 영향 (Influence of ${\beta}-Cyclodextrin$ on Stability and Bioavailability Of Furosemide)

  • 한건;유병권
    • Journal of Pharmaceutical Investigation
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    • 제18권3호
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    • pp.99-105
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    • 1988
  • Inclusion complex formation of furosemide with ${\beta}-cyclodextrin({\beta}-CyD)$ in solid state was confirmed by X-ray diffractometry, IR spectroscopy and differential scanning calorimetry (DSC). The solid complexes of ${\beta}-CyD$ with furosemide in molar ratio of 2 : 1 were prepared by solvent evaporation method. The photodegradation of furosemide in alkaline solution under the light and the hydrolysis of furosemide in acidic solution were not inhibited by complex formation with ${\beta}-CyD$. However, the bioavailability of furosemide was improved by complex formation with ${\beta}-CyD$ after oral administration to rats.

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Novel Withanolides from the Flowers of Datura tatula

  • Srivastava, Anjani;Manickam, M.;Sinha-Bagchia, A.;Sinhaa, S.C.;Ray, A.B.
    • Natural Product Sciences
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    • 제2권1호
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    • pp.9-13
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    • 1996
  • Three new withanolides, designated as withatatulins B, C, and D, were isolated from the fresh flowers of Datura tatula Linn. Detailed spectral analysis of these compounds permitted advancement of their structures respectively, as $5{\beta},6{\beta}-epoxy-12{\beta}$,21-dihydroxy-1-oxo-witha-2,24-dienolide (2), $6{\beta},12{\beta},21-trihydroxy-1-oxowitha$ 2, 4,24-trienolide (3) and $5{\beta},6{\beta},12{\beta}$,21-tetrahydroxy-1-oxo-witha-2,24-dienolide (4a). Withanolides with oxygen functions both at 12 and 21-positions are rare and first reported from Datura species.

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낮은 에너지 감마선과 베타선 모니터링을 위한 Gas Electron Multiplier 검출기의 효율성에 대한 연구 (Research of Efficiency for Gas Electron Multiplier Detector to Monitor Low Energy Gamma-Ray and Beta-Ray)

  • 이순혁;정재훈;이레나
    • 한국의학물리학회지:의학물리
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    • 제25권2호
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    • pp.95-99
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    • 2014
  • 병원을 포함해서서 방사선 물질을 사용하는 모든 사업장에서 방사선 물질의 모니터링은 방사선 안전에 가장 중요한 요소의 하나이다. 본 연구는 방사선 모니터링 시스템에 있어서 GEM 검출기의 활용 가능성을 알아보기 위한 선행 연구로서, GEM 검출기를 제작하고 CdTe 검출기와의 상대적 효율을 구한 결과, 베타와 감마선에 대한 평균 상대 효율이 각각 72%와 4%로서 매우 우수한 성능을 나타냄을 보였다.

Study on Inclusion Complex of Fenbufen with ${\beta}-Cyclodextrin$

  • Kim, Young-Il;Park, Young-Ju
    • Journal of Pharmaceutical Investigation
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    • 제14권3호
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    • pp.136-143
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    • 1984
  • Inclusion complex formation of fenbufen with ${\beta}-cyclodextrin$ in water and in solid state was comfirmed by solubility method, ultra violet absorption, circular dichroism and infra-red spectroscopies, differential thermal analysis, and X-ray diffractometry. A solid complex of fenbufen with ${\beta}-cyclodextrin$ in 1 : 1 molar ratio was prepared by the freeze-drying method, its dissolution characteristics in water and its analgesic and antiinflammatory effect in mouse or rat were examined. The apparent release of fenbufen from the inclusion complex was significantly improved, hut no significant difference in its analgesic and antiinflammatory effect was found.

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Molecular Dynamics Simulation of Enantioselectivity in Metoprolol in complex

  • Jang, Seok-Young;Park, Kyung-Lae
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.356.3-357
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    • 2002
  • Metoprolol (MT) is one kinds of adrenergic beta-blockers. Its (S)-enantiomer is known to be more active than the (R). Recently. the x-ray structure of beta-blocker. (S)-propranolol (a-naphthyl analogue), complexed in a mould fungal cellulase. Cel7A. was reported and the (R)-form did not build any complex. And in our previous study the conformation and stability of MT in carboxymethylated beta-cyclodextrin (BCD) complex was determined by NMR. HPLC, UV and electrophoresis measurement. (omitted)

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배관 내부 방사능 오염도 측정용 ZnS(Ag)/BC-408 phoswich 검출기 개발 (Development of the ZnS(Ag)/BC-408 phoswich detector for monitoring radioactive contamination inside pipes)

  • 김계홍;박찬희;정종헌;이근우;서범경
    • Journal of Radiation Protection and Research
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    • 제31권3호
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    • pp.123-128
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    • 2006
  • 원자력 시설의 해체 시 발생되는 다양한 종류의 폐기물 중에서 배관 내부의 알파/베타선 오염 특성을 직접 평가하기 위해서는 소형의 방사선 검출 시스템이 요구된다. 본 연구에서는 배관 내부의 방사능 오염도를 직접 측정할 수 있는 장비 개발의 일환으로서 기존의 phoswich 검출기와 그 형태가 다른 ZnS(Ag)/플라스틱섬광체 조합의 알파/베타선 동시측정용 phoswich 검출기를 고안하였으며 섬광체 크기 및 검출 시스템의 최적 요건을 실험적으로 확인하고 알파/베타선 신호 분리도를 평가하였다. 그 결과 배관 내부의 오염도 측정에 적합한 phoswich 검출기의 최적 요건 및 배관 내부의 적용 가능성을 확인하였다.

하동 카올린으로부터 제조한 $\beta$-Sialon 분체의 계면특성 (Interfacial Characterization of $\beta$-Sialon Powder Prepared from Hadong Kaolin)

  • 임헌진;이홍림
    • 한국세라믹학회지
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    • 제29권7호
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    • pp.551-557
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    • 1992
  • X-ray diffraction patterns, IR spectra and zeta-potentials of silicon nitride and $\beta$-Sialon powders were investigated before and after surface manipulations. $\beta$-Sialon powder was produced from Hadong Kaolin by the carbothermic reduction and simulataneous nitridation. Isoelectric points of as-prepared Si3N4 and $\beta$-Sialon powders were 8.4 and 7.4, respectively. After both silicon nitride and $\beta$-Sialon powders were oxidized at 80$0^{\circ}C$ for 24 h in air, the isoelectric points of these powders corresponded to that of silica (pH=3). I case of the addition of Darvan C as deflocculant, its isoelectric point was 3 and zeta-potential was nearly constant in the range of pH 5~12. When SN 7347 was used as deflocculant, its isoelectric point was 8.3 and zeta-potential over -156 mV was measured above pH 11.

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기계적 합금화법에 의한 ${\beta}-FeSi_2$ 분말 함성 (Synthesis of ${\beta}-FeSi_2$ Powder by Mechanical Alloying Process)

  • 이충효;조재문;김환태;권영순
    • 한국분말재료학회지
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    • 제8권2호
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    • pp.104-109
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    • 2001
  • The semiconducting ${\beta}-FeSi_2$ compound has been recognized as a thermoelectric material with excel-lent oxidation resistance and stable characteristics at elevated temperature. In the present work, we applied mechanical alloying(MA) technique to produce ${\beta}-FeSi_2$ compound using a mixture of elemental iron and silicon powders. The mechanical alloying was carried out using a Fritsch P-5 planetary mill under Ar gas atmosphere. The MA powders were characterized by the X-ray diffraction with Cu-K $\alpha$ radiation, thermal analysis and scanning electron microscopy. The single ${\beta}-FeSi_2$ phase has been obtained by mechanical alloying of $Fe_{33}Si_{67}$ mixture powders for 120 hrs or for 70 hrs coupled with the subsequent heat treatment up to $700^{\circ}C$. The grain size of ${\beta}-FeSi_2$ powders analyzed by Hall plot method was 44nm.

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G-M 계수관(計數管)을 이용(利用)한 ${\beta}-ray$의 흡수측정(吸收測定) (Experiments of Absorption of Beta Radiation)

  • 이원진;최태진
    • 대한방사선기술학회지:방사선기술과학
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    • 제8권2호
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    • pp.77-81
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    • 1985
  • In this experiments the operation of the Geiger-Mueller tube is investigated by measuring the relationship between the count rate and the applied voltages, The length and slope of the plateau are characteristic of the tube. In our experiments, the average plateau length of the tube is extend for about 100 [V] and the slope 0.017 [%/V]. For normal counting purposes the working voltage is usually selected at value about 50 volts larger than the threshold of the plateau. To investigate the absorption of beta particles by matter. We performed an absorption experiments by using the Al absorber and Sr-90 ($0.125{\mu}Ci$) beta source. The maximum range of the beta radiation can be determined by visual extrapolation of the curve after subtraction of the constant background-rate and the maximum beta energy 2.09 [MeV] can be calculated from the range using an experimental relation.

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