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  • 1
    Electronic Resource
    Electronic Resource
    Spectroscopic studies of new model compounds for poly[N,N′-bis(phenoxyphenyl)pyromellitimide] (1992)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 419-427 
    Details
    ISSN: 0887-624X
    Keywords: polyimide ; models for polyimide characterization of polyimide ; Raman ; infrared ; poly[N,N′-bis(phenoxyphenyl)pyromellitimide] ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New model compounds for poly[N,N′-bis(phenoxyphenyl)pyromellitimide] have been synthesized in order to investigate the formation of imine bonds which are proposed to form during the curing process and lead to crosslinking in the bulk polymer. Raman studies show that terminal amines can react with imide carbonyls during curing to form C=N bonds. The Raman band due to C=N appears at 1656 cm-1 and the band due to C=O closest to the imine bond is observed at 1742 cm-1. These results are in agreement with previously published results on vapor deposited polyimide films.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1992.080300309
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  • 2
    Electronic Resource
    Electronic Resource
    Confirmation of the presence of imine bonds in thermally cured polyimides (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 2751-2758 
    Details
    ISSN: 0887-624X
    Keywords: polyimide ; N-Phenoxyphenylphthalimide ; Raman ; infrared ; poly[N,N′-bis(phenoxyphenyl) pyromellitimide] ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Model compounds for imines formed during the thermal curing of short chain polyimides have been synthesized and characterized. These compounds have imine bonds (C=N) formed by the nucleophilic attack of primary amines on imide carbonyls. The C=N stretching mode appears at 1649-1664 cm-1 in the Raman and infrared spectra of these compounds and the band assigned to the carbonyl mode in an imide ring with an imine bond appears near 1740 cm-1. These compounds have been prepared and characterized to verify the conclusions of a previously reported study in which bands observed in thermally cured short chain polyimides at 1656 and 1742 cm-1 were assigned as the C=N and associated C=O modes, respectively. It has also been confirmed that the C=N stretching mode in the imide model compounds is inherently IR weak and can only be seen if the concentration of imine species is high. © 1993 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080311111
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  • 3
    Electronic Resource
    Electronic Resource
    Optimization of nonvaporizing nylon 6 reactors with stopping conditions (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 30 (1985), S. 4529-4550 
    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: In this study, optimal temperature profiles or histories T(t) are obtained for nonvaporizing plug-flow or batch Nylon 6 reactors using the minimum principle. Two objective functions are studied, one in which the monomer conversion is maximized, and the other in which the undesirable cyclic dimer concentration in the product stream is minimized. The control variable, temperature, is constrained to lie between 220 and 270°C in order to ensure single-phase polymerization. The most significant difference between this study and earlier ones is that the residence or reaction time tf is not specified a priori, but is determined optimally by the use of a “stopping” condition such that the polymer product has a number-average chain length μ, equal to some desired value μn,d. This makes the algorithm considerably more complex, but the results are more meaningful. Qualitatively different optimal temperature profiles are obtained for the two objective functions studied, representing the complex interplay of several opposing factors in determining optimal conditions. This study also lays the foundation for even more complex, but relevant, optimization studies.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1985.070301203
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  • 4
    Electronic Resource
    Electronic Resource
    Inhibition of smooth muscle cell growth in vitro by an antisense oligodeoxynucleotide released from poly(DL-lactic-co-glycolic acid) microparticles (1997)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 35 (1997), S. 525-530 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: We fabricated poly(DL-lactic-co-glycolic acid) (PLGA) 50:50 microparticles loaded with an antisense (AS) oligodeoxynucleotide (ODN) against the rat tenascin mRNA and determined the effect in vitro of the AS-ODN released on smooth muscle cell (SMC) proliferation and migration. AS-ODN was entrapped using a double-emulsion-solvent-extraction technique with high efficiency. Release of AS-ODN was characterized by a small initial-burst effect followed by a period of controlled AS-ODN release for up to 20 days. SMC proliferation studies exhibited dose-dependent growth inhibition with AS-ODN-loaded microparticles. Microparticles loaded with scrambled (SC) ODN showed less growth inhibition than AS-ODN. Moreover, only the AS-ODN-loaded microparticles inhibited migration. These results demonstrate the feasibility of entrapping an AS-ODN to rat tenascin in PLGA microparticles for controlled delivery to inhibit SMC proliferation and migration. © 1997 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Method for studying polymer crystallization in a temperature-gradient field with controlled crystal growth (1972)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 10 (1972), S. 1615-1619 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1972.160100819
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  • 6
    Electronic Resource
    Electronic Resource
    A new cerium(IV) vanadate-based solid membrane electrode for bismuth(III) (1997)
    Weinheim : Wiley-Blackwell
    Electroanalysis 9 (1997), S. 1360-1364 
    Details
    ISSN: 1040-0397
    Keywords: Bismuth selective electrode ; Sensors ; Ion selective electrode ; solid membrane ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A 20% (w./w.) polystyrene-based heterogeneous membrane of inorganic ion-exchanger, cerium(IV) vanadate, has been prepared and used as a bismuth(III) selective electrode. The electrode gives linear potential response in the concentration range 8.0 × 10-5-1.0 × 10-1 mol L-1 with a slope of 19.2 mV per decade of concentration and a fast response time of 50s. The electrode functions well in the pH range 2.0-4.0, in partially nonaqueous media up to 25% (v./v.) alcoholic content and was used over a period of 4 months without any significant drift in potentials. It exhibits selectivity for Bi3+ over a large number of metal ions and can be used as an indicator electrode to determine Bi3+ by potentiometric titration with EDTA.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elan.1140091711
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  • 7
    Electronic Resource
    Electronic Resource
    A Study of Stress in Microwave Plasma Chemical Vapor Deposited Diamond Films Using X-Ray DiffractionDARPA funding for this work is gratefully acknowledged. The authors are also indebted to Dr. John L. Shultz for his assistance with the XRD stress measurements. (1997)
    Weinheim : Wiley-Blackwell
    Chemical Vapor Deposition 3 (1997), S. 129-135 
    Details
    ISSN: 0948-1907
    Keywords: Polycrystalline diamond ; Microwave CVD ; Stress ; X-ray diffraction ; 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
    Notes: Residual stress in polycrystalline diamond films has been studied. Uniform polycrystalline diamond films were deposited on 3.0 in. diameter silicon substrates in a microwave plasma chemical vapor deposition (MPCVD) system. The effects of CH4/H2 ratio, pressure, and power variation on film stress were investigated. The macro-stress, or uniform stress, in the films was measured using the X-ray diffraction (XRD) d-sin2ψ technique. In general, 〈220〉-oriented films exhibited tensile stress and 〈111〉-oriented films were in compression. The micro-stress, or non-uniform stress, calculated from diffraction peak broadening, was observed to be tensile for all samples. Films of relatively small grain size and 〈220〉 orientation showed both the highest micro-stress and the highest macro-stress. Film morphology was analyzed using scanning electron microscopy (SEM) and atomic force microscopy (AFM), while the film texture was studied using XRD. Significant non-diamond carbon was incorporated in 〈220〉-oriented diamond as estimated from the intensity of the broad 1580 cm-1 peak in the Raman spectra. Much less non-diamond carbon was detected in 〈111〉-oriented diamond films. Good correlation between film morphology and measured stress was observed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cvde.19970030304
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  • 8
    Electronic Resource
    Electronic Resource
    NMR spectral studies. XIV.For Part XIII, see Ref. 1. Carbon-13 nuclear magnetic resonance studies on β-lactams (1979)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 12 (1979), S. 34-38 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 NMR spectra of a variety of mono- and bicyclic β-lactams have been measured and the chemical shifts of the ring carbon atoms have been assigned unambiguously. Effects of substituents on the chemical shifts of these carbons are also discussed.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270120108
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  • 9
    Electronic Resource
    Electronic Resource
    NMR spectral studies: XIII - titanium tetrachloride-induced and lanthanide-induced shifts in the proton NMR spectra of β-lactamsPresented in part at the 169th Annual Meeting of the American Chemical Society, Philadelphia, U.S.A., April 1975.1 (1976)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 8 (1976), S. 151-154 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Azetidinones which carry a proton each on C-3 and C-4 often pose a problem in the correct assignment of the resonances due to these protons; titanium tetrachloride has been shown to be an effective and reliable n.m.r. shift reagent to differentiate between these two protons on the basis of their different sensitivities to this reagent. A few compounds were also studied with Eu(fod)3 and Pr(fod)3 for the sake of confirmation.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270080310
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