• Title/Summary/Keyword: H2incorporation

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Synthesis of Pentiptycenediacetylene (Pentiptycene Diacetylene의 합성)

  • Han, Joungmin;Kwon, Hyungjun
    • Journal of Integrative Natural Science
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    • v.2 no.2
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    • pp.69-72
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    • 2009
  • Pentiptycenediacetylene is very useful precursor materials for the synthesis of conducting polymer materials. The incorporation of rigid three-dimensional pentiptycene moieties into conjugated polymer backbones would offer several design advantages. They prevent ${\pi}$-stacking of the polymer backbones and thereby maintain high fluorescence quantum yields and spectroscopic stability in thin films. The pentiptycenediactylene was synthesized and characterized by 1H- and 13C-NMR spectroscopy.

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Study on the Anti-Cancer Effect of Injinchunggan-tang(Yinchenqinggan-tang) (인진청간탕(茵蔯淸肝湯)의 항암효과(抗癌效果)에 관(關)한 연구(硏究))

  • Woo, Hong-Jung;Lee, Jang-Hoon;Kim, Young-Chul
    • The Journal of Korean Medicine
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    • v.20 no.3 s.39
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    • pp.94-104
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    • 1999
  • Objectives: Hepatoma is a very serious disease in Korea and worldwide. Hepatitis B virus (HBV) has proved the most significant cause of hepatoma. We carried out this study to investigate the effect of Injinchunggan-tang (Yinchenqinggan -tang) on inhibiting cell proliferation and DNA synthesis in HepG2.2.15 cell lines and on inhibiting phosphorilation of oncogene (MAP kinase) in NIT /3T3-HEx cells. Methods: First we confinned the Hepatitis B virus producing ability of HepG2.2.15 cells. To investigate the anti-cancer effect of Injinchunggan-tang (Yinchenqinggan-tang), we did the NTS/PMS assay, [3H]-thymidine incorporation assay and transfection of pcDNA-X. We also measured the gene expression through western blotting. Results: Injinchunggan-tang (Yinchenqing gan tang) showed the suppressing effect of HepG2.2.l5 increase in the MTS/PMS assay and the inhibiting effect of DNA synthesis of HepG2.2.15 in the [3H] thymidine incorporation assay. Injinchunggan-tang (Yinchenqinggan-tang) also showed the inhibiting phosphorilation effect of MAP kinase in HBV -X genes. Conclusions: From the above Injinchunggan-tang (Yinchenqinggan-tang) is thought to have an anti-cancer effect on the hepatoma from HBV. It is suggested that further studies on this prescription would give us a better medicine with an anti-cancer effect.

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Gas Permeation Properties of Hydroxyl-Group Containing Polyimide Membranes

  • Jung, Chul-Ho;Lee, Young-Moo
    • Macromolecular Research
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    • v.16 no.6
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    • pp.555-560
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    • 2008
  • A series of hydroxyl-group containing polyimides (HPIs) were prepared in order to investigate the structure-gas permeation property relationship. Each polymer membrane had structural characteristics that varied according to the dianhydride monomers. The imidization processes were monitored using spectroscopic and thermog-ravimetric analyses. The single gas permeability of He, $H_2$, $CO_2$, $O_2$, $N_2$ and $CH_4$ were measured and compared in order to determine the effect of the polymer structure and functional -OH groups on the gas transport properties. Surprisingly, the ideal selectivity of $CO_2/CH_4$ and $H_2/CH_4$ increased with increasing level of -OH incorporation, which affected the diffusion of $H_2$ or the solubility of $CO_2$ in HPIs. For $H_2/CH_4$ separation, the difference in the diffusion coefficients of $H_2$ and $CH_4$ was the main factor for improving the performance without showing any changes in the solubility coefficients. However, the solubility coefficient of $CO_2$ in the HPIs increased at least four fold compared with the conventional polyimide membranes depending on the polymer structures. Based on these results, the polymer membranes modified with -OH groups in the polymer backbone showed favorable gas permeation and separation performance.

Influence of Buckwheat Flour on Physicochemical Properties and Consumer Acceptance of Steamed Bread

  • Lee, Jun-Ho
    • Preventive Nutrition and Food Science
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    • v.15 no.4
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    • pp.329-334
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    • 2010
  • Buckwheat flour was incorporated into steamed breads by adding the flour in the range of 0~9% based on the Baker's percentages and the physicochemical properties and consumer acceptance were investigated. After mixing, kneading, proofing, and molding, bread dough was steamed for 15 min using a steam tray and boiling water. The samples were cooled to room temperature for 15 min and packed in airtight bags for further analyses. pH of the steamed bread decreased slightly while titratable acidity increased significantly from 1.02 to 1.37 mL with the incorporation of more buckwheat flour in the formulation (p<0.05). Water activity was not affected by the buckwheat flour level (p>0.05). Moisture content slightly decreased from 43.72 to 42.30% while soluble solids content increased from 0.63 to 0.85 as the buckwheat flour concentration increased. As a result of the addition of buckwheat flour, the specific volume decreased from 3.31 to 2.57 mL/g; on the other hand, the spread ratio ranged from 2.17 to 2.21 without significant differences among them (p>0.05). At the higher level of buckwheat content, lower scores of all color parameters ($L^*$, $a^*$, and $b^*$-values) were observed. Firmness increased significantly with an increase in buckwheat flour content (p<0.05). Consumer acceptance tests indicated that incorporation of up to 3% buckwheat flour in the formulation of steamed breads did not significantly influence the consumers' acceptability in all attributes tested, except for color and elasticity.

Hydrogen shallow donors in ZnO and $SnO_2$ thin films prepared by sputtering methods

  • Kim, Dong-Ho;Kim, Hyeon-Beom;Kim, Hye-Ri;Lee, Geon-Hwan;Song, Pung-Geun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.145-145
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    • 2010
  • In this paper, we report that the effects of hydrogen doping on the electrical and optical properties of typical transparent conducting oxide films such as ZnO and $SnO_2$ prepared by magnetron sputtering. Recently, density functional theory (DFT) calculations have shown strong evidence that hydrogen acts as a source of n-type conductivity in ZnO. In this work, the beneficial effect of hydrogen incorporation on Ga-doped ZnO thin films was demonstrated. It was found that hydrogen doping results a noticeable improvement of the conductivity mainly due to the increases in carrier concentration. Extent of the improvement was found to be quite dependent on the deposition temperature. A low resistivity of $4.0{\times}10^{-4}\;{\Omega}{\cdot}cm$ was obtained for the film grown at $160^{\circ}C$ with $H_2$ 10% in sputtering gas. However, the beneficial effect of hydrogen doping was not observed for the films deposited at $270^{\circ}C$. Variations of the electrical transport properties upon vacuum annealing showed that the difference is attributed to the thermal stability of interstitial hydrogen atoms in the films. Theoretical calculations also suggested that hydrogen forms a shallow-donor state in $SnO_2$, even though no experimental determination has yet been performed. We prepared undoped $SnO_2$ thin films by RF magnetron sputtering under various hydrogen contents in sputtering ambient and then exposed them to H-plasma. Our results clearly showed that the hydrogen incorporation in $SnO_2$ leads to the increase in carrier concentration. Our experimental observation supports the fact that hydrogen acting as a shallow donor seems to be a general feature of the TCOs.

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Cytological Studies of Diapause in the Silkworm, Bombyx mori L. (가잠의 휴면성에 관한 세포학적 연구)

  • Park, Kwang E.
    • Journal of Sericultural and Entomological Science
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    • v.18 no.2
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    • pp.1-60
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    • 1976
  • In present study, radioautography and electron-microscopy were applied by the author to the elucidation of the mechanism of diapause in Bombyx mori L. (1). Patterns of nucleic acid and protein syntheses during embryonic development of silkworms, incubated at high and at low temperatures, were demonstrated by means of radioautography with labelled precursors of nucleic acid and protein. On the third day after blastokinesis the embryo incubated at high temperature generally incorporated much of the $^3$H-glycine into the brain and the suboesophageal ganglion, and some into other regions. When incubated at low temperature, no difference in the pattern between the brain, the suboesophageal ganglion and other parts was observed. Radioautography with $^3$H-thymidine revealed no significant difference in DNA synthesis in embryos incubated at high and low temperatures. In diapausing eggs twenty days after deposition, only a few cells of the mesoderm incorporated the labelled material into their nuclei, but in the hibernated eggs all the nuclei of the mesoderm had thymidine incorporation. After blastokinesis only the anterior portion of the embryo around the brain and the suboesophageal ganglion had thymidine incorporation; this was not observed in the posterior portion.

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Critical Role of the Cysteine 323 Residue in the Catalytic Activity of Human Glutamate Dehydrogenase Isozymes

  • Yang, Seung-Ju;Cho, Eun Hee;Choi, Myung-Min;Lee, Hyun-Ju;Huh, Jae-Wan;Choi, Soo Young;Cho, Sung-Woo
    • Molecules and Cells
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    • v.19 no.1
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    • pp.97-103
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    • 2005
  • The role of residue C323 in catalysis by human glutamate dehydrogenase isozymes (hGDH1 and hGDH2) was examined by substituting Arg, Gly, Leu, Met, or Tyr at C323 by cassette mutagenesis using synthetic human GDH isozyme genes. As a result, the $K_m$ of the enzyme for NADH and ${\alpha}-ketoglutarate$ increased up to 1.6-fold and 1.1-fold, respectively. It seems likely that C323 is not responsible for substrate-binding or coenzyme-binding. The efficiency ($k_{cat}/K_m$) of the mutant enzymes was only 11-14% of that of the wild-type isozymes, mainly due to a decrease in $k_{cat}$ values. There was a linear relationship between incorporation of [$^{14}C$]p-chloromercuribenzoic acid and loss of enzyme activity that extrapolated to a stoichiometry of one mol of [$^{14}C$] incorporated per mol of monomer for wild type hGDHs. No incorporation of [$^{14}C$]p-chloromercuribenzoic acid was observed with the C323 mutants. ADP and GTP had no effect on the binding of p-chloromercuribenzoic acid, suggesting that C323 is not directly involved in allosteric regulation. There were no differences between the two hGDH isozymes in sensitivities to mutagenesis at C323. Our results suggest that C323 plays an important role in catalysis by human GDH isozymes.

Inhibition of Angiotensin II-Induced Vascular Smooth Muscle Cell Hypertrophy by Different Catechins

  • Zheng, Ying;Song, Hye-Jin;Yun, Seok-Hee;Chae, Yeon-Jeong;Jia, Hao;Kim, Chan-Hyung;Ha, Tae-Sun;Sachinidis, Agapios;Ahn, Hee-Yul;Davidge, Sandra T.
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.2
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    • pp.117-123
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    • 2005
  • A cumulative evidence indicates that consumption of tea catechin, flavan-3-ol derived from green tea leaves, lowers the risk of cardiovascular diseases. However, a precise mechanism for this cardiovascular action has not yet been fully understood. In the present study, we investigated the effects of different green tea catechins, such as epigallocatechin-3 gallate (EGCG), epigallocatechin (EGC), epicatechin-3 gallate (ECG), and epicatechin (EC), on angiotensin II (Ang II)-induced hypertrophy in primary cultured rat aortic vascular smooth muscle cell (VSMC). [$^3H$]-leucine incorporation was used to assess VSMC hypertrophy, protein kinase assay, and western blot analysis were used to assess mitogen-activated protein kinase (MAPK) activity, and RT-PCR was used to assess c-jun or c-fos transcription. Ang II increased [$^3H$]-leucine incorporation into VSMC. However, EGCG and ECG, but not EGC or EC, inhibited [$^3H$]-leucine incorporation increased by Ang II. Ang II increased phosphorylation of c-Jun, extracellular-signal regulated kinase (ERK) 1/2 and p38 MAPK in VSMC, however, EGCG and ECG , but not EGC or EC, attenuated c-Jun phosphorylation increased by Ang II. ERK 1/2 and p38 MAPK phosphorylation induced by Ang II were not affected by any catechins. Ang II increased c-jun and c-fos mRNA expression in VSMC, however, EGCG inhibited c-jun but not c-fos mRNA expression induced by Ang II. ECG, EGC and EC did not affect c-jun or c-fos mRNA expression induced by Ang II. Our findings indicate that the galloyl group in the position 3 of the catechin structure of EGCG or ECG is essential for inhibiting VSMC hypertrophy induced by Ang II via the specific inhibition of JNK signaling pathway, which may explain the beneficial effects of green tea catechin on the pathogenesis of cardiovascular diseases observed in several epidemiological studies.

Hydrogen Production from Photo Splitting of Water Using the Ga-incorporated TiO2s Prepared by a Solvothermal Method and Their Characteristics

  • Chae, Jin-Ho;Lee, Ju-Hyun;Jeong, Jong-Hwa;Kang, Mi-Sook
    • Bulletin of the Korean Chemical Society
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    • v.30 no.2
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    • pp.302-308
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    • 2009
  • This study investigated the production of hydrogen over Ga (1.0, 2.0, and 5.0 mol%)-$TiO_2$ photocatalysts prepared by a solvothermal method. The absorption band was slightly blue-shifted upon the incorporation of the gallium ions, but the intensity of the photoluminescence (PL) curves of Ga-incorporated $TiO_2$s was distinguishably smaller, with the smallest case being the 2.0 mol% Ga-$TiO_2$, which was related to the recombination between the excited electrons and holes. $H_2$ evolution from photo splitting of water over Ga-incorporated $TiO_2$ in the liquid system was enhanced, compared to that over pure $TiO_2$; particularly, the production of 5.6 mL of $H_2$ gas after 8 h when 1.5 g of the 2.0 mol% Ga-incorporated $TiO_2$ was used.

Characterization of Ultra Low-k SiOC(H) Film Deposited by Plasma-Enhanced Chemical Vapor Deposition (PECVD)

  • Kim, Sang-Yong
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.2
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    • pp.69-72
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    • 2012
  • In this study, deposition of low-dielectric constant SiOC(H) films by conventional plasma-enhanced chemical vapor deposition (PECVD) were investigated through various characterization techniques. The results show that, with an increase in the plasma power density, the relative dielectric constant (k) of the deposited films decreases whereas the refractive index increases. This is mainly due to the incorporation of organic molecules with $CH_3$ group into the Si-O-Si cage structure. It is as confirmed by FT-IR measurements in which the absorption peak at 1,129 $cm^{-1}$ corresponding to Si-O-Si cage structure increases with power plasma density. Electrical characterization reveals that even after fast thermal annealing process, the leakage current density of the deposited films is in the order of $10^{-11}$ A/cm at 1.5 MV/cm. The reliability of the SiOC(H) film is also further characterized by using BTS test.