• Title/Summary/Keyword: Beta-ray

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

  • Han, Kun;Yu, Byeong-Kwun
    • Journal of Pharmaceutical Investigation
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    • v.18 no.3
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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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    • v.2 no.1
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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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Research of Efficiency for Gas Electron Multiplier Detector to Monitor Low Energy Gamma-Ray and Beta-Ray (낮은 에너지 감마선과 베타선 모니터링을 위한 Gas Electron Multiplier 검출기의 효율성에 대한 연구)

  • Lee, Soonhyouk;Jung, Jae Hoon;Lee, Rena
    • Progress in Medical Physics
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    • v.25 no.2
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    • pp.95-99
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    • 2014
  • Radiation monitoring is one of the most important process in all places where radioactive material is used including hospital. In this preliminary study, we made GAS electron multiplier (GEM) detector and acquired relative efficiencies in order to see if GEM detector can be useful in radiation monitoring system. The relative efficiency was acquired by using the ratio of GEM detector efficiency to CdTe detector efficiency. The relative efficiency of 72% and 4% was acquired for beta-ray and gamma-ray respectively.

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

  • Kim, Young-Il;Park, Young-Ju
    • Journal of Pharmaceutical Investigation
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    • v.14 no.3
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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
    • Proceedings of the PSK Conference
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    • 2002.10a
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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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Development of the ZnS(Ag)/BC-408 phoswich detector for monitoring radioactive contamination inside pipes (배관 내부 방사능 오염도 측정용 ZnS(Ag)/BC-408 phoswich 검출기 개발)

  • Kim, Gye-Hong;Park, Chan-Hee;Jung, Chong-Hun;Lee, Kune-Woo;Seo, Bum-Kyoung
    • Journal of Radiation Protection and Research
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    • v.31 no.3
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    • pp.123-128
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    • 2006
  • A small radiation detection system is necessary for the direct characterization of alpha/beta-ray contamination inside pipes generated during the decommission of a nuclear facility. In this work, the new type phoswich detector consisting of the ZnS(Ag) and plastic scintillator for ${\alpha}/{\beta}$ simultaneous counting was designed as part of a development of a equipment capable of monitoring radiological contamination inside pipes. The optimum counting conditions in dimensions of scintillator and a detection system were experimentally confirmed and a performance of alpha/beta-ray discrimination was evaluated. As a result, optimum conditions of a detector suitable for monitoring radiological contamination inside pipes and a feasibility of application to pipe-inside were confirmed.

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

  • 임헌진;이홍림
    • Journal of the Korean Ceramic Society
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    • v.29 no.7
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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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Synthesis of ${\beta}-FeSi_2$ Powder by Mechanical Alloying Process (기계적 합금화법에 의한 ${\beta}-FeSi_2$ 분말 함성)

  • 이충효;조재문;김환태;권영순
    • Journal of Powder Materials
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    • v.8 no.2
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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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Experiments of Absorption of Beta Radiation (G-M 계수관(計數管)을 이용(利用)한 ${\beta}-ray$의 흡수측정(吸收測定))

  • Lee, Won-Jin;Choi, Tae-Jin
    • Journal of radiological science and technology
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    • v.8 no.2
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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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