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  • Physics  (5)
  • Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry  (4)
  • Wiley-Blackwell  (9)
  • 1
    Electronic Resource
    Electronic Resource
    Cationic starch-polyacrylonitrile graft copolymer latexesPresented at the 8th Great Lakes Regional Meeting, American Chemical Society, West Lafayette, Indiana, June 3-5, 1974. (1974)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 12 (1974), S. 2683-2692 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Acrylonitrile (AN) was graft-polymerized onto gelatinized cationic starch (CS) possessing diethylaminoethyl ether groups by cerium (IV) initiation to give stable latexlike copolymer dispersions. Dispersions of the latex copolymers, having up to 50% grafted polyacrylonitrile (PAN), air- and heat-dry on glass to clear, adhesive films. Sonification of up to 8% dispersions at 20 Khz reduced their viscosities from 1500-3000 cP to 15-40 cP. Scanning electron microscopy revealed that both nonsonified and sonified dispersions consist of ball-like particles measuring about 0.05-0.15 μ in diameter when dry. The films are formed by coalescence of these particles. The degree to which AN grafts onto CS at ambient temperature is related to the nitrogen content of CS, gelatinization time of CS at 95°C, sequence of AN and cerium(IV) addition, concentration of cerium (IV), concentration of AN, and severity of reaction agitation. Number-average molecular weight values of PAN were about 106 when grafting was conducted under stirring and about 5 × 105 when conducted under shaking action.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1974.170121122
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  • 2
    Electronic Resource
    Electronic Resource
    Wetting properties of polyacetylene films (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1555-1562 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The wetting characteristics of free-standing polyacetylene films were determined by using a standard series of wetting liquids. As-prepared films of cis-polyacetylene were found to contain a significant polar contribution to the surface free energy, which became nearly entirely dispersive upon thermal isomerization to the trans form. Both isomeric forms are characterized by a critical surface tension of wetting γc ≈ 51 mN/m, which is considerably higher than that normally obtained from organic polymers. These results have been interpreted with respect to surface oxidation and tested by examining an oxidized film.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230808
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  • 3
    Electronic Resource
    Electronic Resource
    X-ray diffraction and infrared studies on annealed highly syndiotactic poly(vinyl chloride) (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 15 (1977), S. 1041-1054 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: X-ray diffraction scans and infrared absorption spectra for the C-CI stretching region were obtained for a highly syndiotactic poly(vinyl chloride) (PVC) sample made by the urea clathrate method. When the polymer was annealed at a series of increasing temperatures up to 180°C, x-ray diffraction measurements showed that the crystallinity increases steadily with annealing temperature. Even at 50°C an increase above the original value of 63% was detectable and by 180°C it had reached 70% with a further increase to 78% after cooling to ambient temperature. There is a concurrent significant increase in the lateral crystallite dimensions. However, the infrared spectrum did not change, in agreement with the recent prediction of Moore and Krimm that there is no observable band splitting from interchain interaction in crystalline regions, thus indicating that these C-CI bands cannot be used as a measure of crystallinity. The results from computer curve fitting of the spectra suggest that at least 85% of the polymer consists of long planar syndiotactic sequences and there is therefore substantial order along the chain direction. A mechanism for the increase in crystallinity on annealing, involving the lateral ordering of these regular chains, is discussed. Furthermore, as the temperature is raised some amorphous material is converted to a nematic phase, and this may crystallize during the subsequent cooling.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.180150611
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  • 4
    Electronic Resource
    Electronic Resource
    Observations on the thermoreversible gelation of two-directional arborols in water-methanol mixtures (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 35 (1997), S. 2787-2793 
    Details
    ISSN: 0887-6266
    Keywords: gel ; arborol ; dendrimer ; freeze-fracture electron microscopy ; small-angle X-ray scattering ; Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Reversible gels of two-directional cascade polymers with hydrophilic groups covalently attached by an hydrophobic center chain were studied by light and small-angle X-ray scattering, differential scanning calorimetry, and freeze-fracture transmission electron microscopy. The long, self-assembled fibers interact side-by-side over extended regions to form bundles. A given fiber may participate in several bundles, thus forming a three-dimensional gel network. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2787-2793, 1997
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Cross-linking of poly[1-(trimethylsilyl)-1-propyne] membranes using bis(aryl azides) (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 36 (1998), S. 959-968 
    Details
    ISSN: 0887-6266
    Keywords: PTMSP ; cross-linking ; membranes ; permeability ; Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Cross-linkable poly[1-(trimethylsilyl)-1-propyne] (PTMSP) films were cast from toluene solutions containing PTMSP and either 4,4′-diazidobenzophenone or 4,4′-(hexafluoroisopropylidene)diphenyl azide. The composite films were clear and homogeneous and were cross-linked by UV irradiation at room temperature or thermal annealing at 180°C. Low levels of the bis(aryl azide) (1-5 wt %) were effective in rendering the films insoluble in toluene and THF, both good solvents for PTMSP. The process is simple and effective, and thus PTMSP can be readily converted to mechanically stable membranes with permeabilities and separation factors comparable or higher than those of poly(dimethylsiloxane). The films were characterized by measuring their density, their permeability toward O2 and N2, and their spectroscopic properties. Compared to PTMSP, films containing bis(aryl azide) cross-linkers had lower permeabilities and higher separation factors, consistent with a reduction in free volume. When the films were cross-linked photochemically, the permeabilities declined further and the separation factor increased. Films cross-linked thermally had permeabilities comparable to their PTMSP/azide precursors, and density and swelling measurements suggest that higher free volumes are obtained in thermally cross-linked films. All films stored in air suffered from a slow decline in permeability which may reflect slow surface oxidation of the films. When stored in vacuum, cross-linked films were stable and showed no loss in permeability, but the permeability of uncross-linked PTMSP films stored under the same conditions fell to 70% of their original value in 1 month. We attribute the permeability decline to densification accelerated by impurities and solvents. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 959-968, 1998
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Comparative metabolism of isoleucine by corpora allata of nonlepidopteran insects versus lepidopteran insects, in relation to juvenile hormone biosynthesis (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 19 (1992), S. 1-15 
    Details
    ISSN: 0739-4462
    Keywords: branched-chain amino acid ; 2-keto-3-methylvalerate ; 2-methylbutyrate ; propionate ; acetate ; Manduca sexta ; Hyalophora cecropia ; Samia cynthia ; Peiplaneta americana ; Schistocerca nitens ; Tenebrio molitor ; Diploptera punctata ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We studied the metabolism of [U-14C]isoleucine by intact and homogenized corpora allata (CA) from various insect species to determine how this substrate is converted to precursors of juvenile hormone (JH). CA homogenates of the lepidopterans Manduca sexta, Hyalophora cecropia, and Samia cynthia metabolize [U-14C]isoleucine to several products including 2-keto-3-methyl-valerate, 2-methylbutyrate, CO2, propionate, and acetate. Intact CA of male H. cecropia produce particularly high levels of 2-keto-3-methylvalerate, indicating a highly active branched-chain-amino acid transaminase. In contrast, CA homogenates from the nonlepidopterans Periplaneta americana, Schistocerca nitens, Tenebrio molitor, and Diploptera punctata barely metabolize [U-14C]isoleucine. However, P. americana CA homogenate metabolizes [U-14C]2-keto-3-methylvalerate, the transamination product of [U-14C]isoleucine, more rapidly than does a homogenate of M. sexta CA. Furthermore, intact CA from P. americana incubated with [U-14C]2-keto-3-methylvalerate incorporate low levels of 14C into JH III, but do not metabolize this substrate to JH II or JH I. Intact CA from female Diploptera punctata produce very high levels of JH III, but are also unable to incorporate radiolabel from [U-14C]isoleucine into JH III, which substantiates our findings with other nonlepidopteran CA. The results suggest that CA of nonlepidopteran insects lack an active branched-chain amino acid transaminase and, consequently, are unable to utilize these substrates for JH biosynthesis.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/arch.940190102
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  • 7
    Electronic Resource
    Electronic Resource
    Sublethal effects of permethrin on the chemical communication system of the pink bollworm moth, Pectinophora gossypiella (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 2 (1985), S. 283-293 
    Details
    ISSN: 0739-4462
    Keywords: Pectinophora gossypiella ; sublethal ; permethrin ; behavior ; communication ; pheromones ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Topically applied sublethal doses of permethrin can interrupt chemical communication between the sexes of Pectinophora gossypiella by affecting both the signaler and the responder. The probability of calling by females is reduced when they are treated with doses of permethrin which are much less than the LD50. Similarly, key stages in the behavioral response of males to sex pheromone are effectively blocked at these low doses. Males recover from these effects 4 days after treatment, but calling by females is still significantly reduced at this time. Chemical control of P. gossypiella populations with permethrin may not be limited to mortality, and potentially includes effective control of behavioral aspects of chemical communication.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/arch.940020306
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  • 8
    Electronic Resource
    Electronic Resource
    Purification, partial characterization, and postembryonic levels of amylases from Sitophilus oryzae and Sitophilus granarius (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 2 (1985), S. 415-428 
    Details
    ISSN: 0739-4462
    Keywords: Sitophilus ; S. oryzae ; S. granarius ; S. zeamais ; rice weevil ; granary weevil ; maize weevil ; amylase ; purification ; digestion ; cereals ; feeding ; amylase inhibitors ; adaptive significance ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Amylases from adults of Sitophilus oryzae (L.) and S. granarius (L.) were purified by using a sequential procedure of ammonium sulfate precipitation, glycogen-complex formation, and ion exchange chromatography. Amylase of S. oryaze was purified 47.4-fold to a specific activity of 478 units/mg protein. One amylase unit equals 1 mg maltose hydrate produced/min at 30°C. Amylase of S. granarius was purified 85.4-fold to a specific activity of 453 units/mg protein. Amylase of S. oryzae had a Km of 0.173% for soluble starch and consisted of two anionic isozyrnes with isoelectric points of pH 3.70 and pH 3.76. Amylase of S. granarius had a Km of 0.078% for starch and was a single protein with an isoelectric point of pH 3.76. Purified amylases of both species had molecular weights of 56,000 estimated by sodium dodecyl sulfatepolyacrylamide gel electrophoresis, were activated by chloride, and had double energies of activation calculated from Arrhenius plots. Based on fresh weights of adults feeding on whole wheat through 10 weeks of age, S. oryzae contained three-fold and eight-fold more amylase than S. granarius and S. zeamais Motschulsky, respectively. High amylase levels in S. oryzae may provide this species with an adaptive advantage when feeding on cereals containing naturally occurring amylase inhibitors.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/arch.940020409
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  • 9
    Electronic Resource
    Electronic Resource
    JH III levels in larvae and pharate pupae of Anastrepha suspensa (Diptera: Tephritidae) and in larvae of the parasitic wasp Biosteres longicaudatus (Hymenoptera: Braconidae) (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 13 (1990), S. 53-62 
    Details
    ISSN: 0739-4462
    Keywords: Caribbean fruit fly ; juvenile hormone ; JH esterase ; superparasitism ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: This is the first report of a juvenile hormone (JH) in the Caribbean fruit fly, Anastrepha suspensa (Diptera: Tephritidae). JH III was identified in whole body extracts of L3 (final instar) larvae and pharate pupae (PhP) by using a physicochemical method. JH III was also found in PhP superparasitized (up to 11.3 ± 3.5 S.D. parasites/host) by the solitary wasp Biosteres longicaudatus (Hymenoptera: Braconidae) and in first instars of the parasite. The levels of JH III in hosts were up to 15 × higher than those of the controls. The JH esterase (JHE) levels in the hemolymph of 1-day-old PhP controls were significantly (P 〈 0.05) higher than those of superparasitized individuals. These results suggest that the elevated JH III levels induced by superparasitism may arise from JH buildup due either to decreased JHE activity to continued synthesis of JH by the ring gland or to secretion of JH III by the parasites into the host's hemocoel.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/arch.940130106
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