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  • 1
    Electronic Resource
    Electronic Resource
    Some aspects of orientation in injection molded objects (1972)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 12 (1972), S. 358-363 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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 birefringences of injection molded plates and the birefringence during steady, isothermal shear flow were compared for some amorphous polymers. The materials studied were a polystyrene, a “toughened” polystyrene and an acrylonitrile-butadiene-styrene copolymer. The birefringence of the plates, notably the maximum value for the average over the thickness was found to be related to the shear stress at the cavity wall that had occurred during the mold filling process. This relationship was independent of temperature. To a good approximation, it was also the same as the relationship between the flow birefringence and the shear stress at the wall in isothermal channel flow. It thus appears that the anisotropy of injection molded objects is dominated by the shear stresses during the mold filling process regardless of the temperature and of the macroscopic rate of deformation.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760120508
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  • 2
    Electronic Resource
    Electronic Resource
    Synthesen von Cholinphosphatiden, VI1) 3-Palmitoyl-glycerin-1-phosphorylcholin (D-α-Lysolecithin) und dessen Unwirksamkeit als Substrat für Acyltransferasen (Lecithin-Synthese) (1970)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 738 (1970), S. 161-169 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Choline Phosphatides, VI1).3-Palmitoyl-glycerol-I-phosphorylcholine (D-α-LySO-lecithin) and its Inactivity as Substrate for AcyltransferasesEnzyme reactions controlling the content of the strong lytic agent lysolecithin (monoacylglycerol-3-phosphorylcholine) in cell membranes, i. e. by degradation or by reacylation, are of great importance for the living cell. Lysolecithins, well defined with respect to configuration and structure, can be used as substrates for studying the metabolic fate of these compounds in membranes. Five of the six theoretically possible isomers of lysolecithin have been prepared by De Haas and Van Deenen (1965). - In this paper the synthesis of the hitherto unknown 3-acyl-glycerol-I-phosphorylcholine (B) is described. 3,4-lsopropylidene-D-mannitol (1) has been benzylated to give 1,2,5,6-tetrabenzyl-3,4-isopropylidene-D-mannitol (2). Acid hydrolysis
    Notes: Als Modellsubstanzen für biologische Untersuchungen sind einheitliche, konfigurativ eindeutige Lysolecithine von allgemeinem Interesse. Wir beschreiben erstmals die Synthese eines 3-Acyl-glycerin-1-phosphorsäurecholinesters (B) 3.4-Isopropyliden-D-mannit (1) wird zur Tetrabenzyl-Verbindung 2 benzyliert. Saure Hydrolyse von 2 ergibt 1.2.5.6-Tetrabenzy-D-mannit (3), der mittels Bleitetraacetat zu 1.2-Dibenzyl-glycerinaldehyd (4) Gespalten wird. Reduktion von 4 mit Lithiumalant führt zum 1.2-Dibenzyl-glycerin(5), das durch Veresterung mit Palmitinsäurechlorid das 3-Palmitoryl-Dibenzyl 6 liefert. Aus 6 erhält man bei der katalytischen Hydrogenolyse 2-Benzyl-und 1-Benzyl-3-palmitoyl-glycerin (7bzw. ),die chromatographisch getrennt werden . die Phosphorylierung von 7 mittels ß-Brom-äthyl-dichlorphosphat und die nachfolgende Behandlung mit Trimethylamin ergeben 3-Palmitoyl 2-benzyl-glycerin-1-phosphorylcholin (9), das durch katalytische Hydrogenolyse in 3-Palmitoyl-glycerin-1-phosphorylcholin (10) umgewandelt wird. - Das so dargestellte D-αLysolecithin erweist sich im Gegensatz zu 1 -Palmitoyl-glycerin-3-phosphorylcholin (L-α-Lyso-lecithin) nicht als Substrat für Acyl-CoA : Acylglycerinphosphorylcholin-Acyltransferasen,
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.19707380118
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  • 3
    Electronic Resource
    Electronic Resource
    The mass spectra of some pyrazole compounds (1970)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 3 (1970), S. 1549-1559 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mass spectra of ten pyrazole compounds have been determined. Fragmentation schemes have been derived by means of the metastable defocusing method. The predominant process is cleavage of the nitrogen-nitrogen bond resulting in expulsion of HCN. The process second in prominence is the loss of a nitrogen molecule after initial removal of a hydrogen radical or a substituent, giving the species [C3H2R]+, probably a cyclopropenyl ion. In general, the fragmentation pattern is strongly influenced by the substituent.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210031213
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  • 4
    Electronic Resource
    Electronic Resource
    Preference factors and isotope effects in the loss of H. (D.) and HCN (DCN) from deuterated pyrazoles upon electron-impact (1971)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 5 (1971), S. 1101-1105 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mass spectra of deuterated pyrazoles show that loss of H. and of HCN from the molecular ion occurs with a very high specificity from the 3(5)-position. For the two processes isotope effects and preference factors have been determined. Metastable ion decompositions involving the loss of HCN from the [M - H] -fragment indicate that the identity of the hydrogen atoms in this fragment is lost to a large extent.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210050910
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  • 5
    Electronic Resource
    Electronic Resource
    Fragmentation behaviour and ring expansion of 1-methylimidazole and 1-methylpyrazole upon electron-impact (1973)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 7 (1973), S. 1165-1172 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The relative losses of unlabelled vs. labelled HCN from the [M]+· and [M - 1]+ ions of a number of specifically labelled 1-methylimidazoles (I) and 1-methylpyrazoles (II) have been determined. Hydrogen randomisation in the molecular ions prior to fragmentation is insignificant. Expulsion of HCN follows two distinct pathways: elimination involving positions 2 and 3 (predominant in I) and elimination involving the methyl group and the nitrogen atom at position 1 (predominant in II). The molecular ions eject H· from the methyl groups to a high degree of specificity. In both cases some contribution by position 5 is observed. The resultant [M - 1]+ ions exhibit extensive, but incomplete hydrogen randomisation. Loss of HCN from these ions is consistent with intermediacy of ring-expanded ions, but notably in II a proportion of the HCN is generated from the group. A mechanism for this observation is presented.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210071005
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  • 6
    Electronic Resource
    Electronic Resource
    Loss of HCN and H⋅ from the molecular ion of imidazole (1972)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 6 (1972), S. 1363-1368 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The behaviour of a number of deuterated imidazoles upon electron-impact has been studied. Loss of H⋅ from the molecular ion occurs specifically at the 4(5)-position. Loss of HCN is less specific, the order being 2 〉 4(5) ≫ 1.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210061211
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  • 7
    Electronic Resource
    Electronic Resource
    The construction of an isokinetic sucrose gradient by means of a simple electronic simulation and the application to the fractionation of a mixture of macromolecules (1971)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 143 (1971), S. 67-72 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Nützlichkeit eines isokinetischen Gradienten für die Trennung von Makromolekülen in einem Gravitationsfeld wird diskutiert.Eine einfache Methode zur Herstellung von beliebigen exponentiellen Gradienten durch ein Simulationsverfahren mit einem Oszilloskop und einem Rechteckwellengenerator wird beschrieben.
    Notes: The usefulness of an isokinetic gradient for the separation of macromolecules in a gravitational field has been discussed.An easy way to construct any exponential gradient by means of a simulation-process with an oscilloscope and a square pulse generator has been described.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1971.021430107
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  • 8
    Electronic Resource
    Electronic Resource
    Reaction of N-chlorosulfonylisocyanate with unsaturated polymers. Route to a synthesis of polyampholytes (1973)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 11 (1973), S. 169-172 
    Details
    ISSN: 0360-6384
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1973.130110305
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  • 9
    Electronic Resource
    Electronic Resource
    Interaction of magnesium ions with poly A and poly U (1971)
    New York : Wiley-Blackwell
    Biopolymers 10 (1971), S. 945-960 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The binding of Mg++ to poly A and poly U has been measured quantitatively by using the metallochromic indicator calmagite. The method is described in detail. It is shown that there is electrostatic interaction between the binding sites, viz., the phosphate groups, and the intrinsic association constant, for the specific binding can be determined. After extrapolation to zero ionic strength we find that, for the binding of Mg++ to poly A, kint = 4 × 104 and for that, to poly U, kint = 3 × 104. The intrinsic enthalpy of association is negative. The effect of Mg++ on the secondary structure of poly A and poly U has been studied by measuring the ultraviolet absorbance, optical rotatory dispersion and viscosity as a function of the amount of added Mg++ ions. It was found that Mg++ promotes the formation of a more ordered secondary structure by neutralizing or screening the negative charges. It is concluded from the absorbance measurements that for poly A at pH ≥ 7 and for poly U at pH 〉xs 9 this ordering involves stacking of the bases. Likewise, in solutions of UDP with a pH around 10, base stacking occurs on addition of Mg++.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360100602
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  • 10
    Electronic Resource
    Electronic Resource
    Magnesium binding to yeast ribosomes (1971)
    New York : Wiley-Blackwell
    Biopolymers 10 (1971), S. 11-20 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This paper describes a theoretical and experimental analysis of the binding of magnesium ions to yeast, ribosomes. In the theoretical considerations the interactions between charges located on a macroion are included. In the calculations these interactions result in a term, in which both the charge and the radius of the macroion are accounted for. It appears that on dissociation of the ribosomes both the charge and the radius change, but in such a way, that the term, which accounts for the electrostatic interactions, remains constant. As a consequence the dissociation can lie neglected in the analyses of the binding experiments. Our experiments indicate that two binding reactions between ribosomes and magnesium ions occur. The endpoints of these reactions correspond to about 0.40 and 1.0 equivalent magnesium per ribosomal phosphate, respectively. The pK values are about 3.8 and 2.2, respectively. The experimental results indicate that the effect, of monovalent cations can be explained as a pure ionic strength effect, though the binding of monovalent cations could not be excluded completely.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360100103
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