• Title/Summary/Keyword: ethyl cellulose

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Evaluation on Effectiveness for Preventing Post Surgical Adhesion of Sodium Hyaluronate/Sodium Carboxymethyl Cellulose (HA/CMC) Membrane in Rat Cecum/Peritonium Model (쥐 맹장/복벽 찰과상 모델에서 Sodium Hyaluronate/sodium Carboxymethyl Cellulose 멤브레인의 수술 후 유착방지에 대한 유효성 평가)

  • Lee, Young-Moo;Lee, Young-Woo
    • Membrane Journal
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    • v.15 no.3
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    • pp.213-223
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    • 2005
  • We prepared an anti-adhesion membrane made of sodium hyaluronate/sodium carboxymethylcellulose (HA/CMC) and evaluated its effectiveness for adhesion prevention in a rat model. The anti-adhesion membrane was prepared by lyophilizing HA/CMC solution and cross-linking properly with 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC). In a cecum/abdominal wall abrasion model of Sprague-Dawley rat, cecal serosa and abdominal wall were abraded in $1\times2\;(cm^2)$ with a bone burr after peritoneal midline incision and sutured at 3 points around the injured surface. The denuded cecum was covered with HA/CMC membrane (experimental group), or nothing (control group) and apposed to the abdominal wall. Most of the control group represented 3 or more of adhesion grade at POD 7, 14, 21, and 28, whereas $60\~70\%$ of the experimental group was 2 or less of adhesion grade at 14, 21, and 28. It was similar in the adhesion strength. In a general manner, the adhesion grade and strength showed gradual increasing until POD 14, almost same or a little increasing POD 21, but decreasing POD 28. Also the control group was much higher in adhesion grade, strength, and area than the experimental group. It is expected that the anti-adhesion membrane will have a good clinical result in postoperative adhesion prevention.

A Study on the Extractives of Domestic Major Softwood Needles(I) - Antioxidant Activity of the Extractives from the Needles of Abies koreana Maximowicz and Abies holophylla Wilson - (국내산 주요 침엽수 잎의 추출성분(I) - 구상나무(Abies koreana Maximowicz)와 전나무(Abies holophylla Wilson) 잎 추출성분의 항산화 활성 -)

  • Lee, Sang-Keug;Choi, Don-Ha;Bae, Young-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.34 no.3
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    • pp.73-83
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    • 2006
  • The dried needles (1.5 kg) of Abies koreana and Abies holophylla were ground, extracted with acetone-$H_2O$ (7:3, v/v), concentrated, and fractionated with a series of hexane, methylene chloride, ethyl acetate and water on a separatory funnel. Each fraction was freeze dried, then a portion of ethyl acetate soluble powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. The isolated compounds were identified by cellulose TLC, $^1H$, $^{13}C-NMR$, COSY, HETCOR, FAB and EI-MS. The needles of Abies koreana and Abies holophylla contained a large amount of aromadendrin-7-O-${\beta}$-D-glucopyranoside (compound III), polydatin (compound VI), (-)-rhododendrol-2-O-${\beta}$-D-glucopyranoside (compound VII), in addition to a small amount of (+)-catechin (compound I), kaempferol-3-O-${\beta}$-D-glucopyranoside (compound IV), myricetin-3-O-${\beta}$-D-glucopyranoside (compound V), naringenin-7-O-${\beta}$-D-glucopyranoside (compound II). DPPH analysis was also tested to investigate the antioxidative effects on the isolated compounds and (+)-catechin and polydatin were effective.

Studies on Biological Activity of Wood Extractives (X VIII) -Isolation and Antioxidant Activity of Chemical Constituents from Maackia amurensis- (수목추출물의 생리활성에 관한 연구(X VIII) -다릅나무(Maackia amurensis) 수피의 추출성분의 분리 및 항산화 활성-)

  • Kim, Woo-Jin;Lee, Hak-Ju;Lee, Sang-Keug;Kang, Ha-Young;Choi, Don-Ha;Choi, Tae-Ho
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.6
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    • pp.135-144
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    • 2007
  • The dried barks of Maackia amurensis were ground, extracted with 95% EtOH, concentrated, and fractionated with a series of light petroleum ether, dichloromethane, ethyl acetate and water on a separatory funnel. Each fraction was concentrated, then a portion of dichloromethane and ethyl acetate soluble was chromatographed on a Sephadex LH-20 and silica gel 60 column using a various solvent system as eluents. The isolated compounds were identified by cellulose TLC, $^1H-$, $^{13}C-NMR$, COSY, NOESY, HMQC, HMBC, FAB and EI-MS. The structures were determined as: 7-O-$\beta$-D-glucopyranosyl-4'-methoxyisoflavone, 7-O-$\beta$-glucopyranosyl(1'''->6'')-$\beta$-D-glucopyranosyl-4'-methoxyisoflavone, 7-O-$\beta$-D-glucopyranosyl(1''''->6''')-$\beta$-D-glucopyranosyl(1'''->6'')-$\beta$-D-glucopyransoyl-4'-methoxyisoflavone, 7-O-$\beta$-D-glucopyranosyl-4', 6-dimethoxyisoflavone. The Free radical scavenging activity using DPPH of the isolated compounds were similar with that of BHT but lower than of $\alpha$-tocopherol.

A Study on Rheology Characteristics of Ag Paste for Screen Printing Method for Silicon Solar Cells Electrodes Capable of Forming High Aspect Ratio (고온 소결형 실리콘 태양 전지의 High Aspect Ratio 전극 형성이 가능한 Ag 페이스트의 레오로지 특성 연구)

  • Oh, Tae-Hun;Kim, Sung-Bin;Nam, Su-Yong
    • Journal of the Korean Graphic Arts Communication Society
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    • v.28 no.1
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    • pp.15-24
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    • 2010
  • Photovoltaic solar cells are all in the incident because they are not converted into electrical energy, high-efficiency solar cells in order to reduce the loss of elements must be. Significant factor in the loss of solar cells, optical loss and electrical loss can be divided into. Optical losses occur when the sun will be joined on the surface of the reflection, the shadow loss due to electrodes, and the losses are in the solar wavelengths. Commercialization is currently the most common solar cells on the front of the light incident on the electrode is formed. Therefore, the shadow caused by the electrode to cover the dead area of the sun, due to factors that hinder the absorption of sunlight which is shadowing them and conversion efficiency of solar cells is the inhibition factor. These barriers to eliminate the electrode linewidth reduces the shadowing to reduce, but simply of the electrode line width is reduced electrode area by reducing the series resistance elevates this because to improve the electrode Aspect ratio(height/width) to increase Ag development of paste is required. In this study, aspect ratio of screen-printing method to increase the electrode Ag paste composition of the binder for the characterization of rheology in the shadow of the electrode by reducing the optical loss of the photoelectric conversion efficiency of solar cells to boost the performance measures was. Properties and printability of the paste, the binder resin sintered characteristics that affect the thermal properties are excellent with a good screen printability acrylic resin, ethyl cellulose, using a resin were evaluated. Prepared paste rheology properties, was formed to evaluate the electrode conductivity and aspect ratio.

Formulation of Sustained Release Granule for Venlafaxine-HCl Using Water-Insoluble Polymer (수불용성 고분자를 이용한 염산벤라팍신의 서방형 과립 설계)

  • Park, Ji-Seon;Seo, Jin-A;Jeong, Sang-Young;Yuk, Soon-Hong;Shin, Byung-Cheol;Hwang, Sung-Joo;Cho, Sun-Hang
    • Journal of Pharmaceutical Investigation
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    • v.37 no.2
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    • pp.101-106
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    • 2007
  • Venlafaxine, 1-[2-(dimethylamino)-1-(4-methoxyphenyl)ethyl] cyclohexanol hydrochloride is a novel, nontricyclic antidepressant. venlafaxine is a unique antidepressant that differs structurally from other currently available. The aim ot the study was to formulate sustained-release venlafaxine granules and assess their formulation variables. It consists of two layers, venlafaxine drug layer and sustained release coating layer and manufactured by fluidized bed process. The sustained release of drug could be increased by double-control rising various components in venlafaxine drug layer and sustained-release layer. The drug-containing granules were coated with cellulose acetate, cetyl alcohol and Eudragit RS along with plastisizer such as dibuthyl sebacate as an nano-pore former The release oi venlafaxine depended on the type of Eudragit such as RS, and RL used in the formulation of controlled release layer. These results obtained clearly suggest that the sustained release oral delivery system for venlafaxine could be designed with satisfying drug release profile approved.

Controlled Release of Three Nutrients from Dual-layered Coated Compact Pellets (이중 코팅된 압착 펠렛으로부터 3종 영양소의 방출 제어)

  • Piao, Zong-Zhu;Lee, Eung-Seok;Choi, Yun-Jaie;Lee, Beom-Jin
    • Journal of Pharmaceutical Investigation
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    • v.38 no.3
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    • pp.177-182
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    • 2008
  • The purposes of this study were to prepare dual-layered coated compact pellets containing three nutrients Glucose, Chromium picolinate, Vitamin C) for rumen bypass. The core compact pellets were prepared by an extrusionspheronization method and then double layered coated with pH independent EC (ethyl cellulose) and pH-dependent polymers ($Eudragit^{(R)}$ E100) using a fluid-bed spray coater. Depending on the coating levels of EC and $Eudragit^{(R)}$ E100, release profiles were variable in simulated rumen (pH 6.8) and abomasums (pH 2.0) fluid using USP apparatus I (basket method). When compact pellets were coated with EC (about 10% level in inner layer) and then $Eudragit^{(R)}$ E100 (20% level in outer layer) in a dual-layered manner, rumen-bypass delivery resisting rumen fluid followed by release in abomasums fluid could possible. The friability was also satisfactory based on chewing behavior of ruminants. The dual-layered coated compact pellets showed smooth surface and distinct inner/outer layers using scanning electron microscopy (SEM). The current rumen bypass delivery system can be also applicable to deliver other nutrients in ruminants.

Process Development of Aligning Carbon Nanotube from the Paste (페이스트를 이용한 탄소나노튜브의 수직배양법 연구)

  • Lee, Jae-Kul;Moon, Joo-Ho;Lee, Dong-Gu
    • Journal of the Korean Ceramic Society
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    • v.39 no.5
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    • pp.467-472
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    • 2002
  • Long Carbon Nanotubes(CNTs) were cut by diamond lapping film followed by observation using SEM. The paste was prepared by mixing shortened CNT powder, ${\alpha}$-terpineol used as a solvent, and ethylcellulose as a binder. This paste was deposited on glass substrate by screen printing and extruded by syringe. After screen printing, several post-treatments were performed to control the alignment of CNTs perpendicular to the substrate. The deposited CNTs were scratched by sand paper or diamond lapping film. It was also treated by attachment followed by an immediate detachment using the adhesive tape. SEM observation indicates that excellent vertical alignment of CNTs could be achieved by simple post-treatments from the screen printed-CNTs paste. Similar alignment of CNTs is also observed in the as-extruded CNTs paste.

Extractives from Epimedium koreanum Nakai (삼지구엽초(Epimedium koreanum Nakai)의 추출성분)

  • Lee, Tae-Seong;Cho, Jae-Hyun;Hwang, Byung-Ho
    • Journal of Korea Foresty Energy
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    • v.24 no.2
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    • pp.16-23
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    • 2005
  • The air dried of Epimedium koreanum Nakai was extracted with MeOH and its extractives were concentrated with a vacuum evaporator. The extractives were fractionated with a series of n-hexane, chloroform (${CHCl}_3$), butanol (BuOH), ethyl acetate (EtOAc) and water on a separately funnel. Each fraction was freeze dried to give some dark brown powder. The EtOAc and BuOH soluble fractions were chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-n-hexane mixture as eluents. The isolated compounds were tested with a cellulose TLC developed with TBA and 6% acetic acid and then visualized on UV lamp or sprayed with vanillin-HCl-EtOH. The purified compounds were flavonoids and their glycosides, and organic acid as follows : (+)-catechin, icariin, hyperoside, Ikarisoside A and caffeic acid. The structures of each compounds were confirmed by $^1H-NMR,\;^{13}C-NMR$ and Mass spectra. Also, executed qualitative analysis as use GC/MS(Libraries search) about ${CHCl}_3$ soluble compounds of each part.

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Molecular cloning, expression and characterization of a novel feruloyl esterase enzyme from the symbionts of termite (Coptotermes formosanus) gut

  • Chandrasekharaiah, Matam;Thulasi, Appoothy;Bagath, M.;Kumar, Duvvuri Prasanna;Santosh, Sunil Singh;Palanivel, Chenniappan;Jose, Vazhakkala Lyju;Sampath, K.T.
    • BMB Reports
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    • v.44 no.1
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    • pp.52-57
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    • 2011
  • Termites play an important role in the degradation of dead plant materials and have acquired endogenous and symbiotic cellulose digestion capabilities. The feruloyl esterase enzyme (FAE) gene amplified from the metagenomic DNA of Coptotermes formosanus gut was cloned in the TA cloning vector and subcloned into a pET32a expression vector. The Ft3-7 gene has 84% sequence identity with Clostridium saccharolyticum and shows amino acid sequence identity with predicted xylanase/chitin deacetylase and endo-1,4-beta-xylanase. The sequence analysis reveals that probably Ft3-7 could be a new gene and that its molecular mass was 18.5 kDa. The activity of the recombinant enzyme (Ft3-7) produced in Escherichia coli (E.coli) was 21.4 U with substrate ethyl ferulate and its specific activity was 24.6 U/mg protein. The optimum pH and temperature for enzyme activity were 7.0 and $37^{\circ}C$, respectively. The substrate utilization preferences and sequence similarity of the Ft3-7 place it in the type-D sub-class of FAE.

Chemical Constituents of Saccharides and Triterpenoids in the Korean Native Mistletoes (III) - Structural Features of Water-soluble Polysaccharides from Korean Oak Mistletoe(Loranthus yadoriki Sieb.) - (한국산(韓國産) 겨우살이류(類)의 당류(糖類)와 Triterpenoids의 화학적(化學的) 조성(組成) (III) -한국산 참나무겨우살이(Loranthus yadoriki Sieb.)의 수용성 다당류의 구조적 특성 -)

  • Lee, Su-Hee;Ahn, Won-Yung
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.3
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    • pp.28-36
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    • 1996
  • This experiment was carried out to elucidate the sugar composition of polysaccharides and the structural features of water-soluble polysaccharides(WSP) isolated from Korean oak mistletoe, Loranthus yadoriki Sieb. The 48-hours ball-milled meals of extractive-free dried mistletoe sawdusts were extracted with distilled water for $24hrs{\times}2$ at room temperature. The extracts poured into 95% ethyl alcohol to precipitate. The separated precipitate of WSP, in form of yellowish white powder by lyophilization, was fractionated into four subfractions of WSP-1, WSP-2, WSP-3 and WSP-4 by anion exchange chromatography on DEAE-cellulose column. The sugar composition of WSPs was analyzed by GLC in form of their glycitol acetates, and the structure of polysaccharides in Fractions WSP-1 and WSP-2 was determined by FT-IR and GC-MS after methylation through and acetylation. The sugars of WSPs from Korean oak mistletoe, Loranthus yadoriki, are majorly arabinose and galactose in stem, galactose in leaves very high in content and showed difference in composition and monomeric units between stems and leaves. D-galactose, D-glucose and L-arabinose are the simple sugars consisting of polysaccharides in WSP-1. ($1{\rightarrow}3$)-Linked galactan is the bakcbone with side chain of ($1{\rightarrow}5$)- -L-arabinofuranosyl residues and ($1{\rightarrow}6$)- -D-galactopyranosyl residues, and ($1{\rightarrow}4$)-linked glucan also presents. ($1{\rightarrow}4$)-Linked rhamnogalacturonan and ($1{\rightarrow}4$)- and ($1{\rightarrow}3$)-linked galactan present in WSP-2.

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