• Title, Summary, Keyword: ${\alpha}-F_2O_3$

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Saponins from the Roots of Pulsatilla koreana

  • Kang, Sam-Sik
    • Archives of Pharmacal Research
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    • v.12 no.1
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    • pp.42-47
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    • 1989
  • From the roots of Puisatiila koreana, three monodesmosides(pulsatilla saponins A, B and D) and two bisdesmosides(pulsatilla saponins F and H) were isolated. The structure of these saponins have been determined as hederagenin 3-O-${\beta}$-L-rhamnopyranosyl($1{\to}2$)- ${\alpha}$-L-arabinopyranoside(A), hederagenin 3-O-${\beta}$-D-glucopyrano syl($1{\to}4$) - ${\alpha}$-L-arabinopyranoside(B), hederagenin 3-O- ${\alpha}$-L-rhamnopyranosyl ($1{\to}2$)-[${\beta}$-D-glucopyranosyl($1{\to}4$]-${\alpha}$-L-arabinopyranoside(D), 3-O-${\alpha}$-L-rhamnopyranosyl($1{\to}2$)-{${\alpha}$-L-arabinopyranosyl hederagenin 28-O-${\alpha}$-L-rhamnopyrano syl($1{\to}4$)-${\beta}$-D-glucopyrano syl($1{\to}6$)-${\beta}$-D-glucopyranosyI ester (F) and 3-O-${\alpha}$-L-rhamnopyranosyl($1{\to}2$)-[${\beta}$-D-glucopyranosyl($1{\to}4$)]- ${\alpha}$-L-arabinopyranosyl hederagenin 28-O-${\alpha}$-L-lharnnopyranosyl($1{\to}4$)-${\beta}$-D-glucopyranosyl($1{\to}6$)-${\beta}$-D-glucop yranosyl ester(H) on the basis of chemical and spectral studies. Pulsatilla saponin B is the first report of its presence in plants but saponins A, D, F, and H have recently been isolated from the same genus p. cernua.

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Defect center of $Li^{+}$ ion implanted $Al_2O_3$ ($Li^{+}$ 이온 주입된 $Al_2O_3$의 결함 특성)

  • Kim, Tae-Kyu
    • Progress in Medical Physics
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    • v.5 no.2
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    • pp.13-20
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    • 1994
  • The thermoluminescence(TL) glow curves and the optical absorption of $Al_2O_3$ irradiated with ${\gamma}$-ray, electron, and $Li^{+}$ ion followed by electron irradiation have been investigated to determine the relation of TL peak to its defect type. The TL glow curve of $Al_2O_3$ irradiated with ${\gamma}$-ray shows TL peaks at 380 K, 415 K, and 475 K. The UV photobleached TL glow curve of $Al_2O_3$ irradiated with ${\gamma}$-ray shows that the 380 K and 475 K TL peaks completely disappear while the 415 K TL peak still exists. The electron beam induced TL glow curve of $Al_2O_3$ after $Li^{+}$ ion implantation shows that the TL peak at 440 K is enhanced by a factor of 2 over the TL intensity of unimplanted $Al_2O_3$ while the TL peak at 380 K evidently disappears The implanted $Li^{+}$ ions are assumed to form singly charged interstitial cations and then recombine with electron trapped in F centers to produce F+ centers. The 380 K and 475 K TL peaks are proposed to be associated with F center, while the 415 K and 440 K TL peak are connected with F$^{+}$ center.

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[ $C_{16}H_{19}O_2N_3CuCl_2\;{\cdot}\;H_2O$ ] ($C_{16}H_{19}O_2N_3CuCl_2\;{\cdot}\;H_2O$의 결정 구조)

  • Kim Moon-Jib;Kim Young-Soo;Choi Ki-Young
    • Korean Journal of Crystallography
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    • v.15 no.2
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    • pp.99-103
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    • 2004
  • The structure of $C_{16}H_{19}O_2N_3CuCl_2\;{\cdot}\;H_2O$ has been determined by X-ray diffraction methods. The crystal system is triclinic, space group Pl, unit cell constants. $a=7.6202(9)\; \AA,\; b=8.5943(7) \AA,\; c= 8.6272(6) \AA,\; \alpha= 67.518(6)^{\circ}.\; \beta= 68.043(8)^{\circ},\; \gamma=74.370(8)^{\circ},\; V=478.89(8)\; \AA^3,\; T=295K,\; Z=1,\; D_c=1.504Mgm^{-3}$The intensity data were collected on an Enraf-Nonius CAD-4 Diffractometer with graphite monochromated $MoK\alpha$ radiation $(\alpha=0.7107\;\AA)$. The molecular structure was solved by direct method.』 and refined by full-matrix least squares to a final $R=2.47\%$ for 1659 unique observed $F_0>4\sigma(F_0)$ reflections and 234 parameters.

The Effect of Electroacupuncture at the ST36 on the Electroencephalogram (족삼리(ST36) 전침 자극이 뇌파에 미치는 영향)

  • Gwon, Sun-Cheol;Youn, Dae-Sik;Lee, Sang-Ryong
    • Korean Journal of Acupuncture
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    • v.23 no.1
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    • pp.15-36
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    • 2006
  • Objectives . The aim of this study was to examine the effect of electroacupuncture(EA) at the ST36 on normal humans by using power spectral analysis. Methods : EEG(Electroencephalogram) power spectral exhibits site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity. 32 channel EEG study was carried out in 12 subjects (10 males; age=26.7 years old, 2females; age=28 years old). Results ; In ${\alpha}$ (alpha) band, the power values at Fp2, F7, F3, Fz, FTC1, FTC2, T3, C3, Cz, C4, TT1, TCP1, CP1, CP2,T5, P3, Pz, P4, Po1, Po2, O1, Oz,O2 channels(p<0.05) during the ST36-acupoint treatment were significantly increased. In ${\beta}$ (beta) band, the power values at Fp2, F7, F3, Fz, F4, F8, FTC1, FTC2, T3, C3, Cz, C4, TT1, TCP1, CP1, CP2, T5, P3, Pz, P4, Po1, Po2, O1, Oz, O2 channels(p<0.05) during the ST36-acupoint treatment were significantly decreased. In ${\delta}$ (delta) band, the power values at F7, Fz, T3, C3, TT1, TCP1, CP1, CP2, T5, P3, Pz,T6, Po1, PO2,O1, Oz, O2 channels(p<0.05) during the ST36-acupoint treatment were significantly decreased. In ${\theta}$(theta) band, the power values at F7, Fz, FTC1, T3, TCP1, CP2, TCP2, Po1, Po2 channels(p<0.05) during the ST36-acupoint treatment were significantly decreased. ${\alpha}$/${\beta}$ values at Cz, T5, O1, Oz, O2 channels during the ST36-acupoint treatment were increased. ${\beta}$/${\theta}$ values at Fpl, F7, F3, Fz, F4, F8, FTC1, FTC2, T3, C3, C4, T4, TT1, TCP1, TCP2, TT2, P3, P4, T6, Pol channels during the ST36-acupoint treatment were increased. Conclusions : This results suggest that Electroacupuncture at the ST36 mostly affects the charge on alpha(23 channels), beta(25 channels) bands.

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Dechlorination of HCFC-142b over Supported Pd Catalysts and Solid Acid Catalysts (Pd담지촉매와 고체산촉매를 이용한 HCFC-142b의 탈염소반응)

  • Han, K.Y.;Seo, K.W.;Mok, Y.I.;Park, K.Y.;Ahn, B.S.
    • Applied Chemistry for Engineering
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    • v.9 no.3
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    • pp.372-376
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    • 1998
  • Supported Pd($Pd/AlF_3$, $Pd/{\gamma}-Al_2O_3$) catalysts and solid-acid catalysts(${\gamma}-Al_2O_3$, ${\alpha}-Al_2O_3$, $AlF_3$) were used to perform dechlorination of HCFC-142b(1-chloro-1,1-difluoroethane) in the presence of excess hydrogen. In the reactions the effects of reaction temperature, the mole ratio(r) of $H_2$ to HCFC-142b and the amount of supported Pd on dechlorination of HCFC-142b into HFC-143a(1,1,1-trifluoroethane) or HFC-152a(1,1-difluoroethane) were investigated. The experimental results showed that the conversion of HCFC-142b to product gases were 60% and 92%, respectively, and the selectivity to HFC-143a in the product gases were 58% and 64% for $Pd/AlF_3$ and $Pd/{\gamma}-Al_2O_3$ catalysts, respectively. On these catalysts an optimum reaction condition was found at $200^{\circ}C$ with the space time of reactant gases as 1.05 second and the mole ratio of $H_2$ to HCFC-142b as 3. Solid-acid catalysts were also tested at the same reaction condition. The results showed that the conversions of HCFC-142b to product gases were 12%, 8% and 7%, and the selectivities to HFC-152a were 94%, 92% and 90% for ${\gamma}-Al_2O_3$, ${\alpha}-Al_2O_3$ and $AlF_3$ catalysts, respectively.

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ON A POSITIVE SUBHARMONIC BERGMAN FUNCTION

  • Kim, Jung-Ok;Kwon, Ern-Gun
    • Bulletin of the Korean Mathematical Society
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    • v.47 no.3
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    • pp.623-632
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    • 2010
  • A holomorphic function F defined on the unit disc belongs to $A^{p,{\alpha}}$ (0 < p < $\infty$, 1 < ${\alpha}$ < $\infty$) if $\int\limits_U|F(z)|^p \frac{1}{1-|z|}(1+log)\frac{1}{1-|z|})^{-\alpha}$ dxdy < $\infty$. For boundedness of the composition operator defined by $C_{fg}=g{\circ}f$ mapping Blochs into $A^{p,{\alpha}$ the following (1) is a sufficient condition while (2) is a necessary condition. (1) $\int\limits_o^1\frac{1}{1-r}(1+log\frac{1}{1-r})^{-\alpha}M_p(r,\lambda{\circ}f)^p\;dr$ < $\infty$ (2) $\int\limits_o^1\frac{1}{1-r}(1+log\frac{1}{1-r})^{-\alpha+p}(1-r)^pM_p(r,f^#)^p\;dr$ < $\infty$.

The Anti-hyperlipidemic Effect and Constituents of the 19${\alpha}$-Hydroxyursane-type Triterpenoid fraction Obtained from the Leaves of Rusus crataegifolius

  • Nam, Jung-Hwan;Jung, Hyun-Ju;Tapondjou, Leon Azefack;Lee, Kyung-Tae;Choi, Jong-Won;Kim, Won-Bae;Park, Hee-Juhn
    • Natural Product Sciences
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    • v.13 no.2
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    • pp.152-159
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    • 2007
  • To demonstrate anti-hyperlipidemic activity of the 19${\alpha}$-hydroxyursane-type triterpenoid (19${\alpha}$-HUT)-rich fraction, this fraction was prepared from the extract of Rubus crataegifolius leaves. This fraction was found to have anti-hyperlipidemic effect in a high fat diet-induced rat model from the observation of reduction of abdominal fat pad weights, atherogenic index and hypercholesterolemia at 30 and 60 mg/kg (p.o.) The 19${\alpha}$-HUT fraction was subjected to SiO$_2$, ODS, and/or Sephadex LH-20 column chromatography to yield a new triterpenoid (1) called pomolic acid ester along with nine known triterpenoids which are all 19${\alpha}$-HUTs: euscaphic acid (2), tormentic acid (3), 23-hydroxytormentic acid (4), kaji-ichigoside F$_1$ (5), rosamultin (6), niga-ichigosides F$_1$ (7) and F$_2$ (8), suavissimoside F$_1$ (9) and coreanoside F$_1$ (10). The structure of compound 1 was established as 28-O-formyl-3,19-dihydroxyurs-12-en-28-oic acid on the basis of 2D-NMR spectroscopic data and mass spectrum. Compound 1 was isolated for the first time from natural sources.

[ $C_{28}H_{41}N_4O_4Br\;{\cdot}\;2H_2O$ ] (C_{28}H_{41}N_4O_4Br\;{\cdot}\;2H_2O$의 결정구조)

  • Kim Moon-Jib;Lee Jung-Ah;Jo Kyung-Jin;Choi Ki-Young
    • Korean Journal of Crystallography
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    • v.15 no.2
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    • pp.93-98
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    • 2004
  • The structure of C_{28}H_{41}N_4O_4Br\;{\cdot}\;2H_2O$ has been determined by X-ray deffraction methods. The crystal system is triclinic, space group Pl, unit cell constants, a=9.000(1) $\AA$, b=9.312(3) $\AA$, c=9.344(2) $\AA$, $\alpha=89.37(20)^{\circ},\;\beta=68.81(3)^{\circ},\;\gamma=84.70(4)^{\circ},\;V=726.7(8){\AA},\;T=298K,\;Z=1,\;D_c=1.402Mgm^{-3}$. The intensity data were collected on an Enraf-Nonius CAD4 Diffractometer with graphite monochromated $MoK\alpha$ radiation $(\lambda=0.71073\;{\AA}$. The molecular structure was solved by direct methods and refined by full-matrix least squares to a final $R=5.95\%$ for 2521 unique observed $F_0>4\sigma(F_0)$reflections and 370 parameters.

Structure of $\alpha$,$\beta$-Diphenylsuccinic Acid ($\alpha$,$\beta$-Diphenylsuccinic Acid의 구조)

  • 서일환;윤민중
    • Korean Journal of Crystallography
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    • v.5 no.2
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    • pp.108-112
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    • 1994
  • C19H20O5, Mr=314.337, triclinic,PI, a=10.291(2)A, b=11.218(3)A, c=3.059(1)A, α=74.54(2)°, β=1148.84(1)°, r=109.84(2)°, V=883.283(2)A3, λ(Mo Kα)=0.71069A, μ=0.47 mm-1, F(000)=324, 296K, Z=2, Dx=1.18Mgm-3. Final R=0.0580 for 1637[F>3σ(F)]unique refledtions. α,β-diphenylsuccinic acid, C16H14O4, are connedted with the solvent actone by hydrogen bond O(4)-H˙˙˙O(5), forming a dimer related by related by centrosymmentry thorough intermolecualr carboxylic hydrogen bond O(1)-H˙˙˙O(2)(-x,-y,-z). The nearest distance 3.288A[O(2)˙˙˙O(2)(-x,-y,-z)] between the dimers shows that the packing of the dimer is govermed by van der Waals'force.

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Crystallization of α-Fe2O3/AI2O3(0001) Thin films Studied by Synchrotron X-ray Scattering (α-Fe2O3/AI2O3(0001) 박막 결정화의 방사광 X-선 산란 연구)

  • 조태식
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.8
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    • pp.708-712
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    • 2002
  • The crystallization of amorphous $\alpha$-Fe$_2$O$_3$/$\alpha$-AI$_2$O$_3$(0001) thin films during thermal annealing in air has been studied using real-time synchrotron x-ray scattering. The well aligned (0.02$^{\circ}$/ FWHM) $\alpha$-Fe$_2$O$_3$and Fe$_3$O$_4$interfacial crystallites (50- -thick) coexist on the $\alpha$-AI$_2$O$_3$(0001) in the sputter-grown amorphous films at room temperature. The amorphous precursor is crystallized to the epitaxial $\alpha$-Fe$_2$O$_3$grains in three steps with annealing temperature; i ) the growth of the well aligned $\alpha$-Fe$_2$O$_3$interfacial crystallites, together with the transformation of the Fe$_3$O$_4$crystallites to the $\alpha$-Fe$_2$O$_3$ crystallites, ii ) the growth of the less aligned (3.08$^{\circ}$ FWHM)$\alpha$-Fe$_2$O$_3$grains on the well aligned grains (>40$0^{\circ}C$), and iii) the nucleation of the other less aligned (1.39$^{\circ}$ FWHM) $\alpha$-Fe$_2$O$_3$grains directly on the $\alpha$-AI$_2$O$_3$substrate (>$600^{\circ}C$). The effective thickness thinner than 230 may be very useful for enhancing the epitaxial quality of $\alpha$-Fe$_2$O$_3$/AI$_2$O$_3$(0001) thin films.