ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Crystal structure and nmr conformation of a cyclic pseudotetrapeptide containing urethane backbone linkages (1994)
    New York : Wiley-Blackwell
    Biopolymers 34 (1994), S. 403-414 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Urethane bonds, derived from the hydroxyl group of the tyrosine side chain, have been investigated as a new type of amide bond mimetic in the design of pseudopeptides. The structure of a representative cyclic pseudotetrapeptide that consists of an  -  Ala  -  Tyr(urethane) Ala  -  Tyr (urethane) sequence fused into a rigid ring has been studied in the solid state by x-ray crystallography and in solution by two-dimensional nmr techniques. The cyclic pseudotetrapeptide has an oblong shape. The backbone urethane bonds assume a trans-trans conformation. The carbonyl groups in the ring have an alternating pattern of down, up, down, up with respect to the average ring plane. Solution nmr studies give observed nuclear Overhauser effects and coupling constants largely in agreement with the crystal structure. However, in solution the observed structure is likely to be conformationally averaged, and in the averaged structure, the urethane bond is perpendicular to the plane of the aromatic ring of the tyrosine, while in the crystal it is close to this plane. These differences may be explained by intermolecular hydrogen-bonding interactions. Four aspects of the conformation of the cyclic pseudotetrapeptide were investigated in detail: the tyrosine residue with the attached side-chain urethane bond (the tyrosine-urethane unit), the conformation of the two urethane backbone linkages, the conformation of the two conventional peptide bonds within this unusual ring structure, and the tight turns within the cyclic pseudotetrapeptide. The conformation of the tight turns present in the cyclic pseudotetrapeptide is very similar to that of a β-bend of type II. Intermolecular hydrogen bonding, joining adjacent layers of the cyclic pseudotetrapeptide in the solid state, resemble a parallel β-pleated sheet. The presence of these structural motifs in the cyclic pseudotetrapeptide indicates that the tyrosine urethane unit may find applications in peptide and protein engineering. © 1994 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360340312
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Rapid measurements of elastic modulus and density in polypropylene sheet during aging (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 1579-1584 
    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: New methods for rapidly obtaining elastic modulus and density measurements during isothermal polymer aging are given. The elastic measurements are performed using a Rockwell hardness tester. In this case, the elastic recovery is measured. Rapid density measurements are performed using a “double drop” density gradient columan method. Here, a fully aged and a freshly quenched specimen are dropped simultaneously into the column. Simultaneous column height differences directly measure the density difference of the two specimens. The results of these two experiments extend previously reported aging measurements to relatively low times of aging. A log (time) law for both properties is found to the smallest times measured.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1981.070260513
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The microwave dielectric constants of water-paper mixtures: The role of sheet structure and composition (1983)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 28 (1983), S. 969-981 
    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: A precise technique for determining dielectric constants at microwave frequencies from slotted line measurements is adapted to paper samples. The effects of refining, wet pressing, calendering, and TiO2 addition on the dielectric constants vs. moisture curves are reported and discussed. The observed in-plane dielectric anisotropy is discussed. The importance of considering geometry at the fiber level in explaining the dielectric behavior of paper is stressed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1983.070280306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Polymerization of fluorinated diacetylenes (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 3229-3233 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Perfluoroalkylene diacetylenes, HC≡C—(CF2)n—C≡CH, underwent thermal polymerization at 250-350°C to give glassy polymers stable to 450°C. Partial polymerization of the volatile monomers gave oligomers that are processable at atmospheric pressure. Polymers with similar thermal stability were obtained by transition-metal-catalyzed polymerization of the monomers at moderate temperatures.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1988.080261209
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Thermally stable polymers based on acetylene-terminated adamantanes (1992)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 1747-1754 
    Details
    ISSN: 0887-624X
    Keywords: adamantane polymers ; acetylene-terminated ; high temperature thermosets ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,3-Diethynyl-5,7-dimethyladamantane, 1,3-diethynyl-5-phenyladamantane, 1,3,5-triethynyladamantane, and 3,3′-diethynyl-1,1′-biadamantane, were synthesized and polymerized thermally at 210°C. The thermoset resins obtained were post-cured at 300°C for 16 h to give materials that exhibited onsets of degradation (TGA) in air at 460-477°C and in helium at 460-485°C. The fully cured materials did not exhibit any detectable DSC transitions between 25 and 400°C. An attempt to thermally polymerize 1-ethynyl-3-phenyladamantane was unsuccessful. © 1992 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1992.080300828
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    NMR and CD studies of triple-helical peptides (1992)
    New York : Wiley-Blackwell
    Biopolymers 32 (1992), S. 447-451 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Triple-helix formation of the peptide (Pro-Hyp-Gly)10 was monitored by nmr and CD spectroscopy. The two-dimensional nmr spectra indicated that the Gly Cα H and Pro CδH proton resonances shift upfield in going from the nonhelical to helical form, while hydroxyproline resonances are unchanged. The integrated areas of the helical and nonhelical resonances could be monitored in the one-dimensional nmr spectrum, and indicate that in the (Pro-Hyp-Gly)10 about 90% of the residues are in a defined triple-helical conformation. The introduction of a glycine to alanine substitution or the deletion of a single hydroxyproline residue in the stable triple-helical peptide (Pro-Hyp-Gly)10 still allows trimers to be formed, but the trimers show a substantial loss of triple helix and decreased thermal stability compared with (Pro-Hyp-Gly)10. Two computer models were generated for the Gly → Ala peptide, one with the Ala side chains packed inside the helix and the other with the region containing the alanines forming a β-bend that loops out from the helix. The nmr data is more consistent with the latter model.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360320423
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The mechanism of polyethylene oxidationPresented before the Division of Paint, Plastics and Printing Ink Chemistry, American Chemical Society at a symposium concerned with the oxidation and stabilization of polyolefins, April 1959. (1959)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 2 (1959), S. 281-288 
    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: As evidenced by formation of peroxides and carbonyl, reaction occurs during the oxidation induction period of polyethylene. The meaning of the term oxidation induction period is revealed by the tremendous change in melt index, carbonyl, density, color, tensile, and elongation occurring towards the end of this time period. Hydroperoxide forms long before the end of the oxidation induction period even in the presence of an antioxidant. At any temperature both chain scission and crosslinking occur simultaneously. The rate of oxidation is accelerated by increasing temperature, unsaturation, and branching. Molecular weight seems to have no effect.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1959.070020604
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Thermal depolarization currents of regenerated cellulose films (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 17 (1973), S. 2855-2866 
    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 thermal depolarization current technique is applied to plasticized and unplasticized regenerated cellulose films. In unplasticized cellulose, two depolarization current bands are observed. The band with a current maximum occurring near 298°K (Tm), and with an activation energy, U, of 0.57 eV, is believed to be related to the second-order transition which is known to occur in dry cellulose in the vicinity of 298°K. The second band, with Tm = 215°K and U = 0.26 eV, is also present in the plasticized material, and possibly arises from primary hydroxyl group orientations. In cellulose films plasticized with glycerol, an intense band occurs at 271°K, with U = 0.51 eV, and is attributed to the plasticizer. A third band, occurring in the plasticized material near 300°K, has not been fully investigated.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1973.070170922
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    CKW-Eliminierung aus Wasser durch Vakuum-UV- und UV-Photolyse in Excimer-Durchflußphotoreaktoren (1995)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 67 (1995), S. 96-99 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330670113
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Ein modularer Excimer-Durchflußreaktor zur Reinigung belasteter Abwässer durch Vakuum-UV/UV-Doppelbestrahlung ohne Oxidationsmittelzusatz (1994)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 66 (1994), S. 1523-1527 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330661121
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...