• Title/Summary/Keyword: condensation reaction

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A Solid Phase Synthesis of Dihydro-1,4-dioxin and Dihydro-1,4-oxathiin Carboxanilides Using Polymer-bound Oxime Ester (고체상에 연결된 옥심 에스테르를 이용한 다이하이드로-1,4-다이옥신 및 다이하이드로-1,4-옥사티인 카르복스아닐라이드 유도체의 고체상 합성)

  • Hahn, Hoh-Gyu;Bae, Su-Yeal;Nam, Kee-Dal
    • The Korean Journal of Pesticide Science
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    • v.10 no.1
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    • pp.1-6
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    • 2006
  • A methodology for the syntheses of carboxanilides using solid support of 4-chloro-3-nitorbenzophenone oxime resin 5 was developed. Condensation of 4-chloro-3-nitorbenzophenone resin 6 with hydroxylamine hydrochloride salt gave oxime resin 5. The reaction of oxime resin 5 with dioxin and oxathiin derivatives 7a-d afforded the corresponding polymer-bound dioxin and oxathiin derivatives 9a-d. These polymer-bound resins 9a-d were treated respectively with aniline in the presence of acetic acid resulted in the corresponding dioxin carboxanilides 10a-d (yield, 5%-quantitative).

$\beta$-Glucan enhanced apoptosis in human colon cancer cells SNU-C4

  • Kim, Mi-Ja;Hong, Se-Young;Kim, Sun-Kyu;Cheong, Chul;Park, Hong-Ju;Chun, Hye-Kyung;Jang, Ki-Hyo;Yoon, Byung-Dae;Kim, Chul-Ho;Kang, Soon-Ah
    • Nutrition Research and Practice
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    • v.3 no.3
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    • pp.180-184
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    • 2009
  • The apoptotic effect of bacteria-derived $\beta$-glucan was investigated in human colon cancer cells SNU-C4 using terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, reverse transcription-polymerase chain reaction (RT-PCR) expressions of Bcl-2, Bax, and Caspase-3 genes, and assay of caspase-3 enzyme activity. $\beta$-Glucan of 10, 50, and $100{\mu}g$/mL decreased cell viability in a dose-dependent manner with typical apoptotic characteristics, such as morphological changes of chromatin condensation and apoptotic body formation from TUNEL assay. In addition, $\beta$-glucan ($100{\mu}g$/mL) decreased the expression of Bc1-2 by 0.6 times, whereas the expression of Bax and Caspase-3 were increased by 3.1 and 2.3 times, respectively, compared to untreated control group. Furthermore, the caspase-3 activity in the $\beta$-glucan-treated group was significantly increased compared to those in control group (P < 0.05). Bacterial derived $\beta$-glucan could be used as an effective compound inducing apoptosis in human colon cancer.

Microstructures and Thermal Properties of Polycaprolactone/Epoxy Resin/SiO2 Hybrids

  • He, Lihua;Liu, Pinggui;Ding, Heyan
    • Journal of Adhesion and Interface
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    • v.7 no.4
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    • pp.32-38
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    • 2006
  • A series of organic-inorganic hybrids, PCL/EP/$SiO_2$, involving epoxy resin and triethoxysilane-terminated polycaprolactone elastomer (PCL-TESi) were prepared via polymerization of diglycidyl ether of bisphenol A (DGEBA) with amine curing agent KB-2 and sol-gel process of PCL-TESi. The curing reactions were started from the initially homogeneous mixture of DGEBA, KB-2 and the PCL-TESi. The organicinorganic hybrids containing up to 4.95% (wt) of $SiO_2$ were obtained and characterized by FT-IR, transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). It was experimentally shown that the swelling property in toluene, morphologies and thermal properties of the resulting hybrids were quite dependent on the contents of $SiO_2$. The crosslink network density decreases with increasing of the PCL-TESi. And in TEM, the phase separated morphology of these hybrids was found, which resulted from the coagulation of Si-O-Si networks resulting from $-Si(OC_2H_5)_3$ of PCL-TESi self-curing by hydrolytic silanol condensation, with the advancement of the curing reaction in the modified epoxy resin systems. Meanwhile, the change of the $SiO_2$ content made the morphologies changed from aggregated particles of Si-O-Si in the hybrid to nanocluster of interconnected Si-O-Si particles, then to aggregated Si-O-Si dispersing in the continuous cured epoxy phase again, and last to co-continuous interpenetrating network. The glass transition behavior of the hybrid material was cooperative motion of large chain segments, which were hindered by the inorganic Si-O-Si network. And in TG analysis, the characteristic temperature at 5% of weight loss was evidently increased from $120.5^{\circ}C$ of pure cured epoxy to $277.6^{\circ}C$ of 3.84% (wt) of $SiO_2$ modified epoxy due to the existence of Si-O-Si when PCL-TESi was added in the hybrid.

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A Study on the Effects of High Temperature Thermal Cycling on Bond Strength at the Interface between BCB and PECVD SiO2 Layers (고온 열순환 공정이 BCB와 PECVD 산화규소막 계면의 본딩 결합력에 미치는 영향에 대한 연구)

  • Kwon, Yongchai;Seok, Jongwon;Lu, Jian-Qiang;Cale, Timothy S.;Gutmann, Ronald J.
    • Korean Chemical Engineering Research
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    • v.46 no.2
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    • pp.389-396
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    • 2008
  • The effect of thermal cycling on bond strength and residual stress at the interface between benzocyclobutene (BCB) and plasma enhanced chemical vapor deposited (PECVD) silicon dioxide ($SiO_2$) coated silicon wafers were evaluated by four point bending and wafer curvature techniques. Wafers were bonded using a pre-established baseline process. Thermal cycling was done between room temperature and a maximum peak temperature. In thermal cycling performed with 350 and $400^{\circ}C$ peak temperature, the bond strength increased substantially during the first thermal cycle. The increase in bond strength is attributed to the relaxation in residual stress by the condensation reaction of the PECVD $SiO_2$: this relaxation leads to increases in deformation energy due to residual stress and bond strength.

Solid State Cesium Ion Beam Sputter Deposition

  • Baik, Hong-Koo
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1996.06a
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    • pp.5-18
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    • 1996
  • The solid state cesium ion source os alumino-silicate based zeolite which contains cerium. The material is an ionic conductor. Cesiums are stably stored in the material and one can extract the cesiums by applying electric field across the electrolyte. Cesium ion bombardment has the unique property of producing high negative ion yield. This ion source is used as the primary source for the production of a negative ion without any gas discharge or the need for a carrier gas. The deposition of materials as an ionic species in the energy range of 1.0 to 300eV is recently recognized as a very promising new thin film technique. This energetic non-thermal equilibrium deposition process produces films by “Kinetic Bonding / Energetic Condensation" mechansim not governed by the common place thermo-mechanical reaction. Under these highly non-equilibrium conditions meta-stable materials are realized and the negative ion is considered to be an optimum paeticle or tool for the purpose. This process differs fundamentally from the conventional ion beam assisted deposition (IBAD) technique such that the ion beam energy transfer to the deposition process is directly coupled the process. Since cesium ion beam sputter deposition process is forming materials with high kinetic energy of metal ion beams, the process provider following unique advantages:(1) to synthesize non thermal-equilibrium materials, (2) to form materials at lower processing temperature than used for conventional chemical of physical vapor deposition, (3) to deposit very uniform, dense, and good adhesive films (4) to make higher doposition rate, (5) to control the ion flux and ion energy independently. Solid state cesium ion beam sputter deposition system has been developed. This source is capable of producing variety of metal ion beams such as C, Si, W, Ta, Mo, Al, Au, Ag, Cr etc. Using this deposition system, several researches have been performed. (1) To produce superior quality amorphous diamond films (2) to produce carbon nitirde hard coatings(Carbon nitride is a new material whose hardness is comparable to the diamond and also has a very high thermal stability.) (3) to produce cesiated amorphous diamond thin film coated Si surface exhibiting negative electron affinity characteristics. In this presentation, the principles of solid state cesium ion beam sputter deposition and several applications of negative metal ion source will be introduced.

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Mechanism of Action of Nigella sativa on Human Colon Cancer Cells: the Suppression of AP-1 and NF-κB Transcription Factors and the Induction of Cytoprotective Genes

  • Elkady, Ayman I;Hussein, Rania A;El-Assouli, Sufian M
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.17
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    • pp.7943-7957
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    • 2015
  • Background and Aims: Colorectal cancer is one of the leading causes of death in the world. The aim of this study was to investigate the growth-suppression potentiality of a crude saponin extract (CSENS) prepared from medicinal herb, Nigella sativa, on human colon cancer cells, HCT116. Materials and Methods: HCT116 cells were subjected to increasing doses of CSENS for 24, 48 and 72 h, and then harvested and assayed for cell viability by WST-1. Flow cytometry analyses, cell death detection ELISA, fluorescent stains (Hoechst 33342 and acridine orange/ethidium bromide), DNA laddering and comet assays were carried out to confirm the apoptogenic effects of CSENS. Luciferase reporter gene assays, quantitative reverse transcription-polymerase chain reaction and Western blot analyses were performed to assess the impact of CAERS and CFEZO on the expression levels of key regulatory proteins in HCT116 cells. Results: The results demonstrated that CSENS inhibited proliferation and induced apoptosis. Apoptosis was confirmed by flow cytometry analyses, while CSENS-treated cells exhibited morphological hallmarks of apoptosis including cell shrinkage, irregularity in cellular shape, cellular detachment and chromatin condensation. Biochemical signs of apoptosis, such as DNA degradation, were observed by comet assay and gel electrophoresis. The pro-apoptotic effect of CSENS was caspase-3-independent and associated with increase of the Bax/Bcl-2 ratio. CSENS treatment down-regulated transcriptional and DNA-binding activities of NF-${\kappa}B$ and AP-1 proteins, associated with down-regulation of their target oncogenes, c-Myc, cyclin D1 and survivin. On the other hand, CSENS up-regulated transcriptional and DNA-binding activities of Nrf2 and expression of cytoprotective genes. In addition, CSENS modulated the expression levels of ERK1/2 MAPK, p53 and p21. Conclusions: These findings suggest that CSENS may be a valuable agent for treatment of colon cancer.

Synthesis of N-Alkylcarbazole-3-Vinylene-2-Methyl-4-Dicyanomethylene-4H-Pyran (적색발광재료용 N-알킬카르바졸-3-비닐렌-2-메틸-4-디시아노메틸렌-4H-피란의 합성)

  • Chung, Pyung Jin;Sung, Jin Hee
    • Applied Chemistry for Engineering
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    • v.20 no.1
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    • pp.40-45
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    • 2009
  • N-Alkylcarbazole-3-vinylene-2-methyl-4-dicyanomethylene-4H-pyran derivatives were synthesized by dehydration, $S_N2$, Vilsmeier, and Knoevenagel condensation. They are red-emitting materials for organic light emitting device (OLED) composed of electron donor of N-alkylcabazole-3-vinylene groups and electron acceptor of 2-methyl-4-dicyanomethylene-4H-pyran groups by a conjugated structure. The structural properties of reaction products were analyzed FT-IR and $^1H-NMR$ spectroscopy. The thermal stabilities and reactivities were measured by melting points and yields. The UV-visibles and PL properties can be determined by exitation spectra and emission spectra, respectively.

Preparation of Alumina-Silica Composite Coatings by Electrophoretic Deposition and their Electric Insulation Properties (EPD 방법을 이용한 알루미나-실리카 복합 코팅막의 제조와 전기절연 특성)

  • Ji, Hye;Kim, Doo Hwan;Park, Hee Jeong;Lim, Hyung Mi;Lee, Seung-Ho;Kim, Dae Sung;Kim, Younghee
    • Journal of the Korean Ceramic Society
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    • v.51 no.3
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    • pp.177-183
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    • 2014
  • Alumina-silica composite coating layers were prepared by electrophoretic deposition (EPD) of plate-shaped alumina particles dispersed in a sol-gel binder, which was prepared by hydrolysis and the condensation reaction of methyltrimethoxysilane in the presence of colloidal silica. The microstructure and the electrical and thermal properties of the coatings were compared according to the EPD process parameter: voltage, time and the content of the plate-shaped alumina particles. The electrical insulation property of the coatings was measured by a voltage test. The coatings were prepared by EPD of the sol-gel binder with 5-30 wt% plate alumina particles on parallel electrodes at a distance of 2 cm for 1-10 min under an applied voltage of 10-30 V. The coatings experienced increased breakdown voltage with increasing thickness. However, the higher the thickness was, the smaller the breakdown voltage strength was. A breakdown voltage as high as 4.6 kV was observed with a $400{\mu}m$ thickness, and a breakdown voltage strength as high as 27 kV/mm was achieved for the sample under a $100{\mu}m$ thickness.

Reproducible Synthesis of Periodic Mesoporous TiO2 Thin Film (재현성 있는 메조포러스 TiO2 박막의 제조에 대한 연구)

  • Hur, Jae Young;Lee, Hyung Ik;Park, Young-Kwon;Joo, Oh-Shim;Bae, Gwi-Nam;Kim, Ji Man
    • Korean Chemical Engineering Research
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    • v.44 no.4
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    • pp.399-403
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    • 2006
  • There has been numerous reports for the synthesis of mesoporous $TiO_2$ thin films due to not only the high surface area and regular mesoscale pores but also wide band gap and photo activity. However, the synthesis has been restricted by the limited reproducibility mainly due to the extraordinarily fast hydrolysis and condensation rate of titania precursors. In this report, molar composition of reaction batch (HCl/Ti and Ti/P123) and exterior condition (humidity and temperature) during coating and anealing process. Thereafter, the mesoporous $TiO_2$ thin films were characterized by XRD and TEM

Synthesis of Pyridine and β-Picoline from Acrolein and Ammonia on Pd/SiO2-Al2O3 Catalysts (Pd/SiO2-Al2O3 촉매상에서 아크로레인과 암모니아로 부터 피리딘과 β-피콜린의 합성)

  • Chun, Sung-Woo;Choi, Jung-Kun;Oh, Seok-Youn;Na, Suk-Eun;Park, Dae-Won
    • Applied Chemistry for Engineering
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    • v.2 no.2
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    • pp.138-146
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    • 1991
  • $Pd/SiO_2-Al_2O_3$ catalysts were prepared for the synthesis of pyridine and ${\beta}$-picoline from acrolein and ammonia. The activity of these catalysts decreased considerably by the formation of deposits on catalyst surface during the reaction. TPR study showed that the deposits were formed by the condensation polymerization of acrolein and ammonia. The conversion and production rate of pyridine and ${\beta}$-picoline decreased with the partial pressure of acrolein. The amount of deposits and the regeneration temperature of spent catalysts increased with the partial pressure of acrolein but they were independent of the concentration of ammonia.

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