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  • 1
    Electronic Resource
    Electronic Resource
    Production of interferon-β in a culture of fibroblast cells on some polymeric films (2000)
    Springer
    Cytotechnology 34 (2000), S. 165-173 
    Details
    ISSN: 1573-0778
    Keywords: cell culture ; enhanced production ; fibroblast cells ; interferon-β ; Langmuir-Blodgett film
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Normal human skin (NB1-RGB) cells were cultured in the presenceof polyinosinic and polycytidylic acids, diethylaminoethyldextran, cycloheximide and actinomycin D, which induced humaninterferon-β. The simplest induction method, that requiredonly polyinosinic and polycytidylic acids and diethylaminoethyldextran was found to give the highest production ofinterferon-β by the cells. The cell growth and productionof interferon-β were investigated for NB1-RGB cellscultured on silk fibroin, poly(γ-methyl-L-glutamate),poly(γ-benzyl-L-glutamate) and collagen films prepared bythe Langmuir-Blodgett (LB) and casting methods. The cell densityof NB1-RGB cells cultured on the LB films was found to be higherthan that on the cast films made of the same polymer. Thisindicates that not only the chemical structure of the polymersused for the preparation of the films but the preparationmethods of the films, i.e., casting and LB methods, are also astrong factor affecting the cell growth. The production ofinterferon-β per unit number of cells was found to behigher on the cast films than that on the LB films made of thesame polymer. This is explained by the fact that the optimalsuppressed growth of NB1-RGB cells on the cast films leads tothe enhanced production of interferon-β on the cast filmscompared to those on the LB films prepared by the same polymer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008130223190
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  • 2
    Electronic Resource
    Electronic Resource
    The states of water in gel cellophane membranes (1984)
    Springer
    Polymer bulletin 11 (1984), S. 203-208 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The states of water in gel cellophane membranes were investigated by DSC measurements. An extra exothermic peak, which has not previously been reported, was observed at heating rates slower than 2.5K/min. The peak was ascribed to the crystallization of the liquid water in the heating process. The ratio of the nonfreezing water (often referred to as bound water) (g) to the dry membrane (g) was estimated to be 1.06. This value is far larger than the bound water contents reported for cellulose acetate membranes (Frommer et al. 1972, Taniguchi et al. 1975).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00258031
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  • 3
    Electronic Resource
    Electronic Resource
    Membrane potentials and permeation of NaCl in poly(vinyl alcohol-co-itaconic acid) membranes (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 31 (1986), S. 419-428 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The membrane potential and permeability of NaCl were measured for six crosslinked poly(vinyl alcohol-co-itaconic acid) membranes having various water contents [0.25≤H≤0.83 H2O (g)/swollen membrane (g)] and interpreted by means of an equation derived from Schlögl′s theory. Both results of the membrane potential and the permeability of the membranes having H≥0.34 could be satisfactorily interpreted by the theory. The permeability of NaCl in the membrane of H=0.25 gave, however, an increasing tendency with the decrease of the upstream concentration lower than 0.04 mol/L. It was considered that the concentration dependence reverse to what was caused by the Donnan exclusion might be due to the concentration dependence of the thermodynamic partition coefficient in nonfreezing water of the membrane. By the equation thus derived the membrane potential and the permeability of NaCl in the membrane of H=0.25 were expained qualitatively. The mobility ratios of Na+ and Cl- and the effective charge density in the membranes were discussed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1986.070310210
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  • 4
    Electronic Resource
    Electronic Resource
    Surface-modified polysulfone hollow fibers (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 36 (1988), S. 1753-1767 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Controlled reactions on the inner side, outer side, and both sides of the surfaces of polysulfone ultrafiltration hollow fibers with propane sultone and Friedel-Crafts catalysts were developed. EPMA measurements and MTR spectra for the chemically modified fibers suggested existence of —CH2CH2CH2SO3- segments on the modified surfaces. The modified fibers were found to have smaller molecular weight cut-off than nonmodified fibers, and the fibers modified on the internal surfaces gave better rejection of polyethylene glycol 6000 than those modified on the external surfaces, although the fibers that reacted with solution of the propane sultone and SnCl4 at 70°C and 80°C showed negative rejection of the polyethylene gylcol. Absorption of polyethylene glycol on the modified fibers is estimated to be less than the nonmodified fibers from the flux ratios of aqueous polyethylene glycol solution to pure water. This effect is attributed to the heparinlike active group of modified segments.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1988.070360804
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  • 5
    Electronic Resource
    Electronic Resource
    Enhanced CEA production associated with aspirin in a culture of CW-2 cells on some polymeric films (1999)
    Springer
    Cytotechnology 31 (1999), S. 233-242 
    Details
    ISSN: 1573-0778
    Keywords: cell culture ; carcinoembryonic antigen ; aspirin ; enhanced production ; Langmuir-Blodgett film
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Human colorectal adenocarcinoma tumor (CW2) cells were cultivated in RPMI 1640 media containing 0–7.5 mM aspirin and 10% fetal bovine serum for the production of carcinoembryonic antigen (CEA). By adding aspirin to the media, the production of CEA per cell increased by up to one hundred fold compared to cultivation in normal media containing no aspirin, even though the total cell concentration decreased with the increase in aspirin in the media. The production of CEA was also investigated for CW2 cells cultured on silk fibroin, poly(γ-benzyl-L-glutamate) and poly(γ-benzyl-L-glutamate)/poly(ethylene oxide) diblock copolymer films prepared by the Langmuir-Blodgett and casting methods. The highest production of CEA per cell was observed for the CW2 cells on poly(γ-benzyl-L-glutamate) and its diblock copolymer films prepared by the Langmuir-Blodgett method in the medium containing 5 mM aspirin after 168 hr of inoculation. This originates from the fact that the cell density on the films in the medium containing 5 mM aspirin was the lowest under these conditions. It is suggested that CW2 cells produce CEA more effectively when the cell growth is suppressed by addition of toxic chemicals such as aspirin or by culture on unfavorable films for cell growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008030730814
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  • 6
    Electronic Resource
    Electronic Resource
    Effect of ultraviolet light irradiation on gas permeability in polyimide membranes. 1. Irradiation with low pressure mercury lamp on photosensitive and nonphotosensitive membranes (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 35 (1997), S. 2259-2269 
    Details
    ISSN: 0887-6266
    Keywords: polyimide membrane ; ultraviolet light irradiation ; crosslinking ; physical changes ; gas permeability ; sorption property ; Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Two types of polyimide membranes; one crosslinkable and the other noncrosslinkable using ultraviolet light irradiation (UV irradiation), were prepared and investigated concerning the effect of UV irradiation on their gas permeabilities and selectivities. Permeability and diffusion coefficients for O2, N2, H2, and CO2 were determined using the vacuum pressure and time lag method. Sorption properties for carbon dioxide were carried out to evaluate the changes in the free volume in the membranes due to the irradiation. In both membranes, permeability coefficients for all gases used in this study decreased and permselectivity, particularly for H2 over N2, increased with increasing UV irradiation time without a significant decrease in the flux of H2. The coefficients depended on the membrane thickness, suggesting asymmetrical changes in both membranes due to UV irradiation. It was suggested by an attenuated total reflection (ATR) FTIR method and analysis of the gas sorption properties of the membranes that the physical changes due to UV irradiation at the irradiated side in both membranes significantly affected their gas permeation properties compared with the chemical changes, especially the crosslinking in the crosslinkable type. © 1997 John Wiley & Sons, Inc. J. Polym Sci B: Polym Phys 35: 2259-2269, 1997
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Diffusion of gases in inhomogeneous polymeric membranes (1990)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 28 (1990), S. 2247-2258 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Fick's first law is modified to be applicable for the transport of gases in inhomogeneous polymeric membranes having continuous, concentration-dependent, gradients of solubility and diffusivity along the flux direction (x axis). The membranes are considered to be in the rubbery state, and all gases in the membranes are assumed to be mobile. The modified Fick's law is derived from the consideration of standard chemical potential difference between the membrane and gas phases, and of fugacity coefficients in the membrane. \documentclass{article}\pagestyle{empty}\begin{document} $J=-D\left\{dC/dx - C(d\ln {S/dx})\right\}/L$\end{document} where J is the flux, D is the diffusion coefficient, C is the concentration in the membrane; x is the dimensionless space coordinate (0 ≦ x ≦ 1); S is the solubility; and L is the membrane thickness. The above equation is applicable for the cases where D and S are dependent on concentration. It is also solved analytically or numerically by a simulation method for some model membranes. Flux difference due to the flow direction and concentration profiles in the model membranes are discussed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1990.090281207
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  • 8
    Electronic Resource
    Electronic Resource
    Infrared spectroscopic studies of CO2 sorbed in glassy and rubbery polymeric membranes (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 32 (1994), S. 149-157 
    Details
    ISSN: 0887-6266
    Keywords: membrane ; dual-mode sorption ; infrared spectroscopy ; carbon dioxide ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Infrared spectra of CO2 sorbed in rubbery and glassy polymers were measured to examine the relationships between the spectroscopic data and physical properties of the polymeric membranes. The “V-shape” tendency in the plot of W1 [i.e., half-width of CO2 peak sorbed in the membranes] vs glass-transition temperature (Tg) is observed, and has exactly the same tendency that is widely known from the plot of log D (diffusion coefficient) vs Tg. It is suggested that the membranes having a wider W1 give a faster diffusion coefficient, since W1 is inversely related to the moment of inertia of CO2 in the membranes. Two distinct peaks of CO2 were not observed in the infrared spectra of CO2 sorbed in the glassy polymers. This suggests that the states of CO2 in the Henry mode and Langmuir mode in the glassy polymers are similar in the spectroscopic measurements. © 1994 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1994.090320118
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  • 9
    Electronic Resource
    Electronic Resource
    Gas permeability and stability of poly(1-trimethylsilyl-1-propyne-co-1-phenyl-1-propyne) membranes (1995)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 33 (1995), S. 289-298 
    Details
    ISSN: 0887-6266
    Keywords: gas permeability ; PMSP membrane ; aging effects ; storage environment ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A significant reduction in the gas permeability of the poly(1-trimethylsilyl-1-propyne) (PMSP) membrane was investigated in terms of the membrane thickness and the storage environment. The effects of physical aging were observed with thinner membranes and under vacuum conditions compared with storage in air. The decrease in the permeability coefficient was dependent on the decrease in the hole saturation constant of Langmuir adsorption (C'H), which is related to the volume of the microvoids. Physical aging in the PMSP membrane affected not only the glassy domain but also the rubbery one. To stabilize the permeability of the PMSP membrane, a poly(1-trimethylsilyl-1-propyne-co-1-phenyl-1-propyne) [poly(TMSP-co-PP)] membrane was prepared. Poly(TMSP-co-PP) has the same unit of poly(1-phenyl-1-propyne), which membrane has stable permeability. The poly(TMSP-co-PP) with less than 20 mol % PP content was estimated to be a random copolymer based on theoretical gas permeation analysis. In the poly(TMSP-co-PP) membrane, the relation between the PP content and C'H was similar to the relation between the PP content and the gas permeability. The stability of the permeability was dependent on the PP content. The poly(TMSP-co-PP) membrane containing 10 mol % PP had both high permeability and good stability under some of the aging conditions performed in this work. © 1995 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1995.090330214
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  • 10
    Electronic Resource
    Electronic Resource
    Estimation of diffusion and permeability coefficients of CO2 in polymeric membranes by FTIR method (1996)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 34 (1996), S. 2153-2160 
    Details
    ISSN: 0887-6266
    Keywords: membrane ; diffusion ; dual-mode sorption ; permeation ; infrared spectroscopy ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Infrared spectra of CO2 sorbed in rubbery and glassy polymeric membranes were measured to examine the relationships between the spectroscopic data and the physical properties of the membranes. The two peaks observed in the spectra of CO2 were attributed to the R branch and P branch of CO2 sorbed in the membranes based on the consideration that both peaks were observed at a temperature above the glass transition temperature of the membranes. Apparent diffusion coefficients of CO2 in the membranes were measured from the desorption kinetics of CO2 detected by FTIR spectroscopy. The solubility coefficients of CO2 were also estimated from absorbance spectra of CO2 sorbed in the membranes using Lambert-Beer's rule. The permeability, solubility, and diffusion coefficients estimated by the FTIR method were found to correlate well with the coefficients obtained by conventional methods such as vacuum-pressure or sorption isotherm methods. © 1996 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
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