• 제목/요약/키워드: Polyethylene Oxide

검색결과 186건 처리시간 0.024초

Radiation Technology in the Preparation of Polyethylene Oxide Hydrophilic Gels and Immobilization of Proteases for Use in Medical Practice

  • E.I.Vereschagin;Han, Do-Hung;A.W.Troitsky;O.V.Grishin;S.E.Petrov;E.P.Gulyaeva;L.A.Bogdanova;M.V.Korobeinikov;V.L.Auslender
    • Archives of Pharmacal Research
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    • 제24권3호
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    • pp.229-233
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    • 2001
  • This Paper deals with the development of a technology for making a hydrophilic gel of Polyethylene oxide reception in which radiating ability is employed to cause cross-linking of Polymers in a water solution. The gel of polyethylene oxide was shown to be nontoxic contain 5-50% of polymer and be useful in composite medicinal forms along with biologically active substances including Bac. subtilis proteases. Proteases immobilized in the gel possess high thermal stability and proteolytic activity and are readily applied in medicine. The effect of immobilized proteolytic and glucolytic enzymes of Bac. subtillis (Immozimase) on the warm ischemia-reperfusion (I/R) which can cause hepatic and jejunum injury was also studied. These enzymes were immobilized on water-soluble polymer polyethylene glycol by means of an electron beam. The number of degraanulated mast cells as well as serum ALT after I/R in the group with Immozimase was decreased to almost half as compared with the control group. Pretreatment with Immozimase resulted in significant reduction of hepatic and gut neutrophil accumulation as compared with control animals. It was concluded that Immozimase has a protective effect for hepatic and gut ischemia/reperfusion, and this effect seems to be associated with prevention of leukocyte accumulation .

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Deposition of Functional Organic and Inorganic Layer on the Cathode for the Improved Electrochemical Performance of Li-S Battery

  • Sohn, Hiesang
    • Korean Chemical Engineering Research
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    • 제55권4호
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    • pp.483-489
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    • 2017
  • The loss of the sulfur cathode material through dissolution of the polysulfide into electrolyte causes a significant capacity reduction of the lithium-sulfur cell during the charge-discharge reaction, thereby debilitating the electrochemical performance of the cell. We addressed this problem by using a chemical and physical approach called reduction of polysulfide dissolution through direct coating functional inorganic (graphene oxide) or organic layer (polyethylene oxide) on electrode, since the deposition of external functional layer can chemically interact with polysulfide and physically prevent the leakage of lithium polysulfide out of the electrode. Through this approach, we obtained a composite electrode for a lithium-sulfur battery (sulfur: 60%) coated with uniform and thin external functional layers where the thin external layer was coated on the electrode by solution coating and drying by a subsequent heat treatment at low temperature (${\sim}80^{\circ}C$). The external functional layer, such as inorganic or organic layer, not only alleviates the dissolution of the polysulfide electrolyte during the charging/discharging through physical layer formation, but also makes a chemical interaction between the polysulfide and the functional layer. As-formed lithium-sulfur battery exhibits stable cycling electrochemical performance during charging and discharging at a reversible capacity of 700~1187 mAh/g at 0.1 C (1 C = 1675 mA/g) for 30 cycles or more.

알파술폰 고급지방산 폴리에틸렌 글리콜 에스테르류의 합성 (Synthesis of ${\alpha}-Sulfonated$ Fatty Acid Polyethylene Glycol Ester)

  • 김진현;연영흠;정노희;남기대
    • 한국응용과학기술학회지
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    • 제15권2호
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    • pp.83-92
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    • 1998
  • ${\alpha}-sulfonated$ fatty acid polyethylene glycol esters with polyethylene oxide(addition, 3, 5, 10mol) were synthesized through esterification of ${\alpha}-sulfonated$ fatty acid methyl esters with alkyl chain length $C_{12}{\sim}C_{18}$. Their compounds were separated with column chromatography, and confirmed by TLC. Quantitative analysis of all the sulfonates were performed according to JIS K-3362 method, and ethylene oxide unit number were determined by ISO 2270 method. Structural properties of ${\alpha}-sulfonated$ fatty acid methyl esters and their derivatives were also identified from IR, and $^1H$ NMR spectra.

Penetration Enhancement of β2-Selective Agonist, Tulobuterol, Across Hairless Mouse Skin

  • Kim, Byung-Do;Choi, Hoo-Kyun
    • Journal of Pharmaceutical Investigation
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    • 제33권2호
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    • pp.79-84
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    • 2003
  • The effects of various pressure sensitive adhesives (PSA) and enhancers on the percutaneous absorption of tulobuterol were investigated. The permeation rate of tulobuterol through hairless mouse skin from various adhesives was evaluated using a flow-through diffusion cell system at $37^{\circ}C$. The permeability of tulobuterol was variable depending on the physicochemical property of the PSA. The permeation rate of tulobuterol from polyethylene oxide grafted acrylic adhesive matrix was higher than that from other PSA matrices. The flux of tulobuterol was $4.37{\pm}0.34\;{\mu}g/hr/cm^2$ from polyethylene oxide grafted acrylic adhesive matrix. When the effects of various enhancers on the percutaneous absorption of tulobuterol from grafted acrylic adhesive were evaluated, Plurol $oleique^{\circledR}$ showed higher flux than all other enhancers tested.

전기방사를 이용한 PEO 나노섬유 제조 (Fabrication of Polymer Nanofibers using Electrospinning)

  • 김길태;안영철;이재근;;성창모
    • 한국분무공학회지
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    • 제8권2호
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    • pp.31-37
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    • 2003
  • Polymeric fibers with nanometer-scale diameters are produced by electrospinning method. When the electrical forces at the surface of a polymer solution or melt overcome the surface tension, then electrospinning occurs and nanofibers are made. Polyethylene oxide(PEO) have been electrospun in our laboratory Electrospun PEO fibers are observed by scanning electron microscopy or transmission electron microscopy In thl:; study. the average diameter of the electrospun fibers decreases with decreasing PEO concentration and increasing electric field strength. The optimal conditions for producing uniform PEO 100nm fibers are the 10wt% PEO concentration at a voltage 25 to 30kV and a distance of 10cm from tip to collector.

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