ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Polymer and Materials Science  (9)
  • Life and Medical Sciences  (3)
  • Humans
  • Astrophysics
  • 1980-1984  (13)
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 3487-3491 
    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 solution blend of poly(vinyl chloride) and a segmented poly(ether ester) and blends containing these two polymers plus poly(methyl acrylate) were investigated by dynamic mechanical analysis and electron microscopy. The binary blend, which contained 75% by weight of the poly(ether ester), showed only one loss peak, but also evidence of some phase separation. It is believed that the polyether sequences of the poly(ether ester) are extensively mixed with poly(vinyl chloride). Poly(methyl acrylate) was added to spread the damping range and produce a material of potential use as an acoustic damper. It is evident from both electron microscopy and dynamic mechanical analysis that poly(methyl acrylate) is substantially incompatible in the other polymers.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 3467-3473 
    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: Binary blends of poly(vinyl chloride) and a poly(ether urethane) containing 20 and 40 weight percent, respectively, of poly(vinyl chloride) have been prepared by solution blending from tetrahydrofuran and their degree of mixing investigated using dynamic mechanical analysis. In the polyurethane, transitions were found at -19°C and -119°C. The former was attributed to the glass transition and the latter to a Schatzki type of motion of the polyether sequences. This latter transition occurred at a temperature which is higher than the literature value for the low temperature transition in poly(tetrahydrofuran), which is equivalent to the polyether sequence in the polyurethane. This discrepancy is attributed to the influence of neighboring hard segments present because of incomplete segmental phase separation of the polyurethane. For the blends only one very broad transition was observed, indicating that there was substantial mixing of these two polymers. Three ternary blends were prepared, also by solution blending, containing poly(vinyl chloride), Hytrel, and the polyurethane in the ratios 1:1:1, 1:2:1, and 2:1:1, respectively. In the first two blends there was clear evidence of phase separation. It was only in the 2:1:1 blend that an apparently significantly compatible material resulted.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 103 (1980), S. 349-353 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Adipocytes were isolated from the Wistar and Sprague-Dawley strains of rats of different ages. An impermeable reagent, mercury-[3H] dextran, was used to quantitate the sulfhydryl groups on the surface of these cells. The application of this reagent after the pre-reduction of cells with 2-mercaptoethanol yielded a measure of the total sulfhydryl and disulfide groups located there. Aging was found to significantly decrease the ratio of the number of exofacial sulfhydryl groups to the total number of exofacial sulfhydryl and disulfide groups.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 402-408 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Previous studies on the biological effects of the 2′,3′-dideoxynucleosides (ddNs) have shown that while ddAdo is lethal to E. coli, ddThd has minimal effects on the growth of mammalian cell lines and that it inhibits retrovirus infection of some cell lines but not others. Previous studies have also shown that the 5′-triphosphate of ddThd, ddTTP, selectively inhibits cellular DNA polymerases β and γ and retroviral reverse transcriptases. Cellular DNA polymerase α is relatively resistant to ddTTP. We have extended these findings to show that the 5′-triphosphates of the other 3 ddNs (ddATP, ddCTP, and ddGTP) affect cellular DNA polymerases α, β, and γ in the same fashion as does ddTTP. We also show that all four ddNs in concentrations up to 100 μM have negligible effects on the growth of NIH Swiss 3T3 cells. These negligible effects may be due to inefficient intracellular phosphorylation of each nucleoside to the triphosphate. We have determined that, in several different cell lines, ddThd is phosphorylated only at a very slow rate to ddTTP, and in the one cell line tested (monkey CV-1 cells), ddAdo and ddGuo are also poorly phosphorylated. Both ddAdo and ddGuo, and probably ddThd, are converted by CV-1 cells to additional unknown compounds which may have biological activity. The four ddNs display effects of different magnitudes on certain virus infections. Although 30 μM ddThd inhibits herpes simplex I infection of CV-1 cells by 50%, 30 μM ddAdo has no effect. Infection of NIH Swiss 3T3 cells by 334C murine leukemia virus is inhibited 70-80% by ddAdo, ddCyd, and ddThd at 50 μM, but inhibition by 50 μM ddGuo is 100%.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 183 (1982), S. 781-788 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Copolymerization of acrylamide with allyl glycidyl ether yielded water soluble polymers containing an epoxy group; addition of a crosslinking agent, N,N′-methylenebis(acrylamide), to the copolymerization mixtures resulted in the formation of similar though water insoluble polymers. Condensation of a potent beta-adrenergic antagonist Alm—H, which contains a reactive amino group, with a polymer containing an epoxy group yeilded a pharmacologically active polymer. The polymer containing the epoxy group was also converted, by reaction with sodium thiosulfate and subsequent reduction, into a mecapto groups containing polymer which was also water soluble. The latter polymer was converted by condensation with a beta-adrenergic antagonist Alm—COCH2Br, which contains a reactive bromoacetamido group, into a pharmacologically active polymer.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 21 (1983), S. 119-127 
    ISSN: 0730-2312
    Keywords: endogenous lectin ; BHK cell adhesion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: A β-galactoside-binding endogenous lectin extracted from bovine heart binds to the surface of baby hamster kidney (BHK) cells. The binding to and agglutination of cells is reduced in certain ricin-resistant mutants (Ric cells) in parallel with the decreased number of binding sites for the selective agent, ricin, a galactose-specific plant lectin. However, clear differences in the binding specificities of bovine lectin and ricin are shown by the effect of neuraminidase. BHK cells and Ric mutant cells treated with neuraminidase bind similar amounts of the bovine lectin compared with untreated cells, and ricin binding is greatly increased.The mammalian lectin immobilised on inert glass mediates the attachment and spreading of normal BHK cells and agglutinates these cells in solution. Ricin-resistant mutant cells respond poorly. These results are consistent with a role of endogenous lectins in cellular adhesiveness and show that cell adhesion may be regulated by the density of specific surface receptors for lectins.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The proton nmr spectra of the oligoribonucleotides in the series CpXpG, ApXpG, CpApXpUpG, and ApGpXpC (X = A, G, C, and U), together with the reference compounds CpG, ApG, CpApUpG, and ApGpC, have been measured. A complete analysis of all the nonexchangeable base protons and the ribose H-1′ protons was made. The insertion of a nucleotide X into a oligoribonucleotide led to shift changes at both nearest-neighbor and next-nearest-neighbor positions, which were rationalized in terms of the shielding abilities of the various bases. The derived shielding trends in the ApGpXpC series of compounds were successfully used to predict the chemical shifts of resonances in the related ApGpXpCpU series.
    Additional Material: 13 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 21 (1982), S. 169-179 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthetic cyclic octapeptides of general structure cyclo[Glu(γOBzl)-Sar-Gly-(N-R)Gly]2 (R = n-hexyl and cyclohexyl) transport calcium ions selectively across organic phases and phospholipid membranes. We have now used proton nmr spectroscopy (360 MHz) to study the solution conformation(s) of their calcium complexes. When Ca(ClO4)2 was added to solutions of these peptides in CDCl3, nmr spectra of the resulting calcium complexes were characteristic of a single C2-symmetric conformer. From a Karplus-Bystrov analysis of vicinal coupling constants in both the peptide backbone and Glu side chain (treated as an ABCC′MX spin system), in conjuction with model-building studies, a structure was proposed in which the calcium ion is bound in an octahedral-type complex by the four (coplanar) carbonyl groups of the (all-trans) Glu-Sar and Gly-(N-R)Gly peptide bonds. Occurrence of preferred rotamers about Glu side chain Cα-Cβ bonds indicated that restricted rotation in peptide side chains arises upon calcium binding.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The variable-temperature proton nmr spectra of the oligoribonucleotides in the series CpApX and the series ApGpX, X = A, G, C, U, together with the parent dimers CpA and ApG have been measured. A complete analysis of all the nonexchangeable base proton resonances and ribose H-1′ proton resonances was made. The presence of trends in the shielding abilities of the various bases at both the nearest-neighbor and next-nearest-neighbor positions were identified. The observed shieldings could be used to predict the chemical shifts of protons in related systems. Based on the empirical results from ribodinucleoside monophosphates, the temperature-dependent behavior of the J1′2′ coupling constants of the triribonucleotides suggested that the compounds in the CpApX series stacked from the 5′-end to the 3′-end, while those in the ApGpX series stacked from the 3′-end to the 5′-end.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 20 (1982), S. 1001-1012 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Samples of polyethylene and polytetrafluorethylene were sintered at 200°C. The samples were cleaved and cut, and the two types of surfaces were studied by ESCA. The possibility of chemical interaction between the two polymers and the formation of a transitional layer is postulated on the basis of the results. A morphological model of the structure of these samples is given.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...