• Title/Summary/Keyword: Precusor

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A Comparison Study on Nutrients, Phytoestrogens and Food Intakes of Postmenopausal Women according to the Climacteric Symptom (폐경 여성의 갱년기 증상에 따른 영양소, 식물성 에스트로겐 및 식품 종류별 섭취 비교)

  • Kim, Mi-Hyun;Bae, Yun-Jung
    • Journal of the East Asian Society of Dietary Life
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    • v.16 no.5
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    • pp.533-541
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    • 2006
  • The purpose of this study was to investigate the relation between climacteric symptoms and intakes of various nutrients, phytoestrogens and foods in postmenopausal women. We conducted anthropometric measurements, questionnaire interview and 24hr dietary recall for 3 days in 128 postmenopausal women aged $49{\sim}64$. The subjects were divided into the two groups, NCMS(non climacteric symptoms group) and CMS(climacteric symptoms group), according to the severity of the climacteric symptoms. There were no significant difference in anthropometric measurements, maternal factors(menarche age, menopause age), subjective health status, frequency of exercise, smoking and drinking status between the two groups. The Mg and lignan precusor intakes of the NCMS group were significantly higher than those of the CMS group. Mg, lignan precusor, pulse and seed intakes had negative correlations with the severity of climacteric symptoms. From this study results, Mg, phytoestrogen(especially some lignan) and some food groups like as pulse and seeds may prevent and reduce climacteric symptoms in postmenopausal women.

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Micro-Raman characterization of isolated single wall carbon nanotubes synthesized using Xylene

  • Choi, Young Chul
    • Carbon letters
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    • v.14 no.3
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    • pp.175-179
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    • 2013
  • Isolated single wall carbon nanotubes (SWCNTs) were synthesized by chemical vapor deposition (CVD) using a liquid precursor (xylene) as a carbon source. Transmission electron microscopy (TEM) and atomic force microscopy confirmed the isolated structure of the SWCNTs. Micro-Raman measurements showed a tangential G-band peak ($1590cm^{-1}$) and radial breathing mode (RBM) peaks ($150-240cm^{-1}$). The tube diameters determined from the RBM frequencies are in good agreement with those obtained from TEM. The chirality of the isolated SWCNTs could be determined based on the energy of the laser and their diameter. A further preliminary study on the nitrogen doping of isolated SWCNTs was carried out by the simple use of acetonitrile dissolved in the precusor.

Loss of cholinergic innervations in rat hippocampus by intracerebral injection of C-terminal fragment of amyloid precursor protein

  • Han, Chang-Hoon;Lee, Young Jae
    • Korean Journal of Veterinary Research
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    • v.48 no.3
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    • pp.251-258
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    • 2008
  • The neurotoxicity of C-terminal fragments of amyloid precusor protein (CT) is known to play some roles in Alzheimer's disease progression. In this study, we investigated the effects of the recombinant C-terminal 105 amino acid fragment of amyloid precusor protein (CT105) on cholinergic function using CT105-injected rat. To study the effects of CT105 on septohippocampal pathway, choline acetyltransferase (ChAT) positive neurons were examined in the medial septum and in the diagonal band after an injection of CT105 peptide into the lateral ventricle. Immunohistological analysis revealed that the number of ChAT-immunopositive cells decreased significantly in both medial septum and diagonal band. In addition, CT105 decreased ChAT-immunopositive cells in the hippocampal area, particulary in the dentate gyros. To study the effect of amyloid beta peptide ($A{\beta}$) and CT105 on the cholinergic system, each peptide was injected into the left lateral ventricle, and acetylcholine (ACh) levels were monitored in hippocampus. ACh level in the hippocampal area was reduced to 60% of control level in $A{\beta}$-treated group, and the level was reduced to 15% of control level in CT105-treated group, at one week after the injection. ACh level was further reduced to 35% of control in $A{\beta}$-treated group, whereas the level was slightly increased to 30% of control in CT105-treated group at 4 weeks after the injection. Taken together, the results in the present study suggest that CT105 impairs the septohippocampal pathway by reducing acetylcholine synthesis and release, which results in damage of learning and memory.

Efficient Synthesis of 10-Membered Lactone Possessing Ring-olefin at 7,8-Position (7,8번 위치에 이중결합을 갖는 10-membered lactone의 효율적인 합성)

  • 서영거;이지연;조윤상
    • YAKHAK HOEJI
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    • v.39 no.1
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    • pp.31-35
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    • 1995
  • An unusual 10-membered lactone possesing ring-olefin at 7, 8-position has been efficiently synthesized. The $\omega$-hydroxy acid as a cyclization precusor was derived from $\varepsilon$-caprolactone in 41% overall yield of 7 steps and efficiently cyclized by Mukaiyama procedure.

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Variations of Reaction Sequence with Precusor Mixing Methods in the Formation of $Pb(Zn_{0.6}Mg_{0.4})_{1/3}Nb_{2/3}O_3$[PZMN] ($Pb(Zn_{0.6}Mg_{0.4})_{1/3}Nb_{2/3}O_3$[PZMN] 합성시 전구체 혼합방법에 따른 반응 경로변화)

  • 김봉철;김정주;김남경;조상희
    • Journal of the Korean Ceramic Society
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    • v.35 no.5
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    • pp.458-464
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    • 1998
  • Variations of reaction sequence of $Pb(Zn_{0.6}Mg_{0.4})_{1/3}Nb_{2/3}O_3$[PZMN] with precusor mixing methods were ex-amined using X-ray diffraction and dielectric characteristics. In the present study three different types of precursor mixing methods (oxide mixing PbO+$ZnNb_2O_6+MgNb_2O_6$[Zn+MN] and PbO+(Zn,Mg)$Nb_2O_6$[ZMN] precursor mixing) were adopted. When the oxide mixing method was used for the PZMN synthesis a Zn-rich perovskite phase and pyrochlore phase were formed. Compared with PbO+ZN+MN precursor mixing method the PbO-ZMN precursor led to a lowering of the formation temperature for perovskite sin-gle phase. These variation of composition and formation temperature of the perovskite phase were dis-cussed in terms of the difference in the solid-reaction requence between these three different types of pre-cursor mixing.

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Thermal Cyclization of Aromatic Polyhydroxyamides and its Derivatives(I) (폴리히드록시아미드와 그 치환체의 고리화 반응(I))

  • Kim, Eun-Kyoung;Kim, Myung-Kyoon;Baik, Doo-Hyun
    • Proceedings of the Korean Fiber Society Conference
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    • 2002.04a
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    • pp.347-350
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    • 2002
  • Wholly aromatic polybenzoxazoles(PBO) are well established as high performance materials with excellent thermal stability and mechanical properties. Heterocyclic precursor polymers such as polyhydroxyamides(PHA) have been interested in the field of high performance flame retardant polymers.[1] Precusor polymers have the advantages that they are easier to process, don't require strong solvents and can adsorb large amounts of heat energy during the cyclization process. (omitted)

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