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
Filter
  • Polymer and Materials Science  (8,218)
  • Cell & Developmental Biology
  • 1965-1969  (9,137)
  • 1920-1924  (118)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Masthead (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969) 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Influence of temperature on the helix sense of several polyamino acids (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 21-27 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An increase in temperature causes an increase in the amplitudes of intramolecular and intermolecular motions and mainfests itself as an increase in the effective radii of the various atoms, especially hydrogen atoms. If one uses a Lennard-Jones 6-12 potential function to account for nonbonded interactions, this increase in the radius of the hydrogen atom is equivalent to a modification of the coefficient of the repulsive part of the Lennard-Jones potential. Accordingly, this effect of increasing temperature on the helix sense of several polyamino acids is computed by allowing the effective radius of the hydrogen atom to increase. It is found that the preferred sense of several polyamino acid helices changes from right- to left-handed as the temperature is increased. This accounts for recent experimental observations of changes in helix sense with temperature.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Helix-coil transition for poly(L-glutamic acid) in water-ethanol solutions (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 57-68 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Potentiometric titrations and some complementary optical rotation data are presented for solutions of poly(L- glutamic acid) (PGA) in several H2O-ethanol mixtures. The data allow the determination of the intrinsic pK (pK0), slope of the apparent. pK (pKapp), versus degree of ionization curves and of the enthalpy of ionization as a function of ethanol concentration. The variation of the degree of ionization at which the helix-coil transformation occurs with ethanol and temperature is also determined. Finally free energy, enthalpy, and intropy changes associated with the helix-coil transformation for the uncharged conformers are determined from the titration curves. The effect of the ethanol is to increase the stability of the helical conformation of PGA for both the charged and the uncharged forms of the polymer. The stabilization of the uncharged helix is essentially an entropic effect.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Low-frequency infrared bands and chain conformations of polypeptides (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 91-99 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Infrared spectra of polypeptides were measured in the region of 1800-400 cm-1. For the α-helical form, disordered form, and antiparallel-chain β-form, amide V band- arising from N-H out-of-plane bending models were observed at 610-620, around 650, and 700-705 cm-1, respectively, and amide V′ bands arising from N-D out-of-plane bending modes were observed at 455-465, around 510, and a 515-530 cm-1, respectively. These correlations are useful for conformation diagnoses, particularly for copolyamino-acids or proteins which are not oriented. The nature of low-frequency amide bands are discussed with reference to potential energy distributions calculated for the α-helical form and β form.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Etude, par spectroscopie infra-rouge, de la conformation de quelques composés peptidiques modèles (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 69-89 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some experimental data are given on the infrared spectra between 3300 and 3500 cm-1 of dilute solutions in carbon tetrachloride of three types of model compounds: CH3-CONH-CH(R1)-CONH(R2), (I); CH3-CON(CH3)-CH(R1)-CONH(R2), (II) and CH3-CONH-CH(R1)-CON(R2)2, (III). In studying the N-H stretching bands, it was found that there are two types of intramolecular hydrogen bonds in these molecules; these result in two different cyclized conformations, C5 and C7, which contain respectively, five and seven atoms in the ring. By using model substances I, II, and III, in which the nitrogen atoms are unequally substituted, it is possible to identify the N-H stretching bands which are to be ascribed to the N-H oscillators included in the two different chelated conformations. It is found also that the stretching frequency of a free N-H oscillator depends upon the substituent on the nitrogen atom. Thus, it is possible to observe, with some of the model compounds I, four different absorption bands located at 3340, 3420, 3440, and 3460 cm-1. The first two are ascribed to the N-H oscillators included in the H—bonds which lock the C7 and C5 conformations; the last two correspond to free N-H which differ with the substituent on the nitrogen atom.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Interaction of poly-L-lysine with nucleic acids. V. Effect of salt concentration (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 153-155 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Quantum mechanical approach to the conformational analysis of macromolecules in ground and excited states (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 207-213 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Molecular orbital calculations of the extended Hückel type have been used to study the conformations of glycyl and alanyl residues in ground and excited states. The ground-state surfaces show features similar to those obtained with the standard calculational methods in which the total energy is partitioned into components such as torsions, nonbonded and electrostatic interactions. The molecular orbital calculations provide the first independent theoretical check on such calculations. The excited-state surfaces, Uniquely available from the molecular orbital calculations, exhibit a better definition and sharpening of potential minima in the sterically allowed regions.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Computation of molecular weight averages for DNA molecules containing both preformed and randomly induced single-strand breaks (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 215-221 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We derive equations for calculating the number-, weight-, and z-average lengths between single-strand breaks in DNA molecules. Provision is made for the existence of preformed breaks under genetic control: these are assumed to be fixed in number in each molecule, but may be variable in position. Breaks due to random degradation may be superimposed on the pre-existing breaks. An example is given for illustrative purposes.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Studies on the secondary structure of ribosomal ribonucleic acid components of rabbit reticulocytes (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 223-239 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The conformation in solution of fractionated 30 S and 19 S ribosomal RNA from rabbit reticulocytes has been studied by optical rotatory dispersion, analysis of thermal melting profiles and their derivatives, and spectrophotometric acid-base titration. From a consideration of the limitations of these methods, it has been possible to set limiting values on the degree of base-pairing and the lengths of the double helices: between 60 and 80% of the bases in 19 S and 30 S RNA are estimated to be paired. The paired segments are not shorter than 4 base pairs, and evidence from other sources is available which indicates that they are not longer than 8-16 base pairs. The spread of helix lengths is greater in the 30 S than in 19 S RNA; and other differences are noted. Several distinct populations of double helices, differing in their thermal stability, are present. Estimates are presented from spectrophotometric and titration data for the base compositions of the paired and unpaired regions.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070209
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Instability in diffusing fluid layers (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 251-263 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A small perturbation analysis is carried out to determine the stability of a fluid containing two layers of diffusing solutes in a common solvent and acted upon by a uniform gravitational field. It is found that instability can arise even though the unperturbed diffusion does not lead to the formation of a density inversion within the fluid.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070211
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Abbreviated nomenclature of synthetic polypeptides (polymerized amino acids). Tentative rulesDocument of the IUPAC-IUB Commission on Biochemical Nomenclature (CBN), approved by IUPAC and IUB in October, 1967, and published by permission of the International Union of Pure and Applied Chemistry, the International Union of Biochemistry, and the official publishers of IUPAC, Messrs. Butterworths Scientific Publications. (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 161-166 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Kinetics of denaturation of DNA (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 475-493 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of denaturation of DNA have been studied by relaxation techniques. Examination of the terminal relaxation times for a variety of DNA's under a variety of conditions has shown that DNA denaturation is principally a hydrodynamically limited process. Measurements within the helix-coil transition have demonstrated that the experimentally measured terminal relaxation times are a function of the following: (1) position in the helix-coil transition; (2) ionic strength of the solvent; (3) solvent viscosity; (4) DNA concentration; (5) molecular weight; (6) number and position of single-strand breaks. The dependence of the terminal relaxation time on the above mentioned factors can be attributed to hydrodynamic effects. Thus a hydrodynamic model for DNA unwinding is required. The model which best fits the data involves the assumption of a rotational frictional coefficient independent of molecular weight. This assumption is suggested by the fact that the relaxation time is proportional to the first power of the molecular weight.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070406
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Counterion binding in partially neutralized poly(D-glutamic acid) and poly(DL-glutamic acid) (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 495-502 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Sodium counterion association with partially neutralized poly(D-glutamic acid) or poly(DL-glutamic acid) was measured by use of Wall's transference method with radioactive sodium. In the region where both polyacids are in completely random coil form, fractions of association were considerably less than that with poly(acrylic acid) in the same region of degree of neutralization. Even in the region where poly (D-glutamic acid) is in the helical form, the fraction of association was less than that with poly(acrylic acid) in the same region. No pronounced characteristics attributable to counterion association corresponding to the helix-coil transition could be found. The association phenomena were discussed on the basis of a rodlike model of polyelectrolyte.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070407
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    NMR studies in solution of poly-L-proline (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 411-415 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The isomerization of poly-L-proline in different solvents has been studied by NMR spectroscopy. Different resonance signals for the CHα protons have been obtained for the two different helical conformations of thus compound, namely form I and form II.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070311
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Synthesis of poly-L-asparagine and poly-L-glutamine (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 417-422 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Poly-β-N-diphenylmethyl-L-asparagine and poly-γ-N-diphenylmethyl-L-glutamine were prepared from the corresponding N-carboxyanhydrides. Poly-L-aspuragine and poly-L-glutamine were obtained by removal of the diphenylmethyl protecting groups with liquid anhydrous hydrofluoric acid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070312
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Hydrogen-tritium exchange of the random chain polypeptide (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 379-393 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Hydrogen-tritium exchange character of poly-D,L-alanine was studied in detail as a model for the hydrogen exchange behavior of the unhindered, polymeric peptide group. The random chain nature of poly-D,L-alanine was evident in the uniformity of exchange rate of all its hydrogens and in the similarity between this rate and that of random chain poly-D,L-lysine and other known, unhindered secondary amide groups. An equilibrium isotope effect favoring the binding of tritium over protium to the extent of 21% was measured. Specific acid and base catalysis of the exchange and the absence of detectable general catalysis were demonstrated. Apparent energy of activation is 17 kcal/mole for deprotonation, largely due to dependence of Kw on temperature, and 15 kcal/mole for protonation, which correlates with the extreme apparent pK. The hydrogen -tritium exchange half-time rate; of poly-D,L-alamine at any pH and temperature (T: °C) is given by the equation: \documentclass{article}\pagestyle{empty}\begin{document}$$ \[t_{\frac{1}{2}} \,(\min )\, = \,200\,\, \times \,10^{0.05{\rm T}} /\,[10^{{\rm pH} - 3} \, + \,10^{3 - {\rm pH}} ]\] $$\end{document}
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070309
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Optical rotation of some α-1,4-linked glucopyranosides in the system H2O-DMSO and solution conformation of amylose (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 581-593 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The specific rotation of starch components, corrected for refractive index variation, exhibits a discontinuity in the region of the water-dimethyl sulfoxide (H2O-DMSO) system that corresponds to the composition of the complex 2H2O-DMSO. This discontinuity is a property dependent upon the presence of a number of consecutively linked α-1,4 glucose units and, therefore, must reflect a change in symmetry of a segment, of polymer chain. The optical rotation of amylose between 26.5 and 92.5°C. does not change in DMSO and is only slightly lowered in water at the higher temperature. The behavior of amylose in both DMSO and H2O is like that of a random coil, as indicated by viscosity and sedimentation measurements. These results may be interpreted either as being compatible with models of amylose in solution in which the polymer backbone has helical twist, or as indicating removal of strong interactions between polymer chain segments by a good solvent.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070414
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Calorimetric investigation of the influence of polymer concentration on the transition enthalpy in the helix-coil transition of the double-stranded helical complex poly(A + U) (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 611-613 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070416
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Polarized ultraviolet absorption spectra and electronic transitions of poly-L-proline (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 614-618 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070417
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Masthead (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969) 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    John Warren Williams (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 1-3 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Chemically reacting systems of the type A + B ⇄ AB. II. Osmometry (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 5-19 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The osmotic pressure equation for nonideal, associating systems of the type nA +mB ⇄ AnBm, has been derived, by using the assumption yAnBm/yAnyBm = 1. This treatment can also be applied to related associations such as nA + mB ⇄ AB + AB2 + A2B + …. From osmotic pressure experiments on the pure reactants it is possible to obtain the molecular weights (MA and MB) of the reactants and also the virial coefficients (BAA and BBB) of the reactants. The osmotic pressure of a nonreacting mixture of A and B can be calculated from these measurements. It can be used along with osmotic pressure measurements on equilibrium mixtures of A and B to obtain expressions containing the equilibrium constant (or constants) and the cross-virial coefficients (BAB and BBA). Several procedures are described for the evaluation of the equilibrium constant (or constants) and the BAB or BBA terms. It appears that this procedure is a general one which is applicable to associations of the type nA + mB ⇄ AB + A2B + AB2 + …. By correcting for nonideal behavior, one should then be able to apply it to any method available for analyzing ideal associations of the types considered here. In addition it is possible, subject to certain restrictions, to analyze associations of the type 3A + B ⇄ A2 + AB.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Differential elution of histones from gel-trapped nuclei (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 39-58 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method has been developed for characterizing at, submicrogram levels the heterogeneity of histones from purified nuclei. The histones are eluted with a smooth concentration gradient from nuclei trapped in polyacrylamide-gel threads and are collected in a micro fraction collector suitable for volumes in the 10-100 μl range. The gradient and fraction collection systems are governed by cam driven syringes. Samples obtained are subjected to electrophoresis in a starch-gel system and the gels are stained with a highly sensitive stain specific for guanidinium groups. Seven major and a similar number of minor components are demonstrated in the histones. The method of differential elution of trapped macromolecules is suitable for use with systems other than nuclei and histones.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Evaluation of lipoprotein size-density distributions from sedimentation coefficient distributions obtained at several solvent densities. I. Theory (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 119-132 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is presented for the treatment of distribution functions obtained by ultra-centrifugal sedimentation velocity experiments on the plasma lipoproteins, so that adequate corrections can he made for the effects of diffusion and concentration dependence of the sedimentation coefficient. The method involves the use of modified equations derived from those presented in 1952 by Gosting for the transform from g* (S) to g(S) distributions. The evaluation of the molecular parameters of lipoprotein density and size, from a set of g(Si°) distribution functions obtained in solvents of varying density, is also outlined. Preparations of the β-lipoprotein of human plasma are found to follow a bivariate normal distribution that requires evaluation of five parameters, x̄1, σ1, x̄2, σ2and p. The first two represent the mean and standard deviation of the lipoprotein density, the third and fourth the same quantities for the size, expressed as ft “logarithmic diameter parameter”, and the final value is a measure of the correlation between these two variables.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Conformations of poly-L-valine in solution (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 133-133 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Masthead (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969) 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070201
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Nuclear magnetic resonance investigation of the helix to random coil transformation in poly-α-amino acids. I. Poly-L-alanine (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 155-171 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High-resolution nuclear magnetic resonance spectra at 100 MHz and 220 MHz have been obtained on two samples of poly-L-alanine of differing molecular weights (2500 and 42 500) in the chloroform-trifluoroacetic acid system under various conditions of solvent composition, temperature, and polypeptide concentration. Separate helix and random coil peaks are observed for the α-CH and peptide NH backbone proton resonances, thereby permitting the determination of helix content. This observation of separate peaks demonstrates that the lifetimes of the helix and random coil portions of poly-L-alanine have lower limits of about 10-1 sec. It is suggested that solvent-peptide versus peptide-peptide hydrogen bond competition, coupled with a destabilizing effect of the trifluoroacetic acid on the helix, is responsible for the helix-random coil transformation.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Preparative fractionation of lignin by gel-permeation chromatography (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 135-153 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The combination of an agarose gel (Bio-Gel A) and a dioxane-water (1:1) solvent system allowed the fractionation, on a preparative scale, of a very polydisperse, non-derivatized lignin preparation (enzymatically liberated lignin prepared from sweetgum sapwood with Lenzites trabea). Three fractions differing markedly in molecular weight were obtained. A gel of crosslinked alkylated dextran (Sephadex LH-20) with the same solvent system allowed division of the lowest molecular weight fraction into two fractions. These materials were characterized by measurements of intrinsic viscosity and number-average molecular weights in dimethylformamide and dioxane-water. It was established that the two highest molecular weight fractions were associated in an average trimeric form in dioxane-water (1:1) as compared to the form (considered to be molecular) that occurred in dimethylformamide. Molecular size distributions and eluant volumes of the fractions were determined with a Sephadex G-100-formamide system, the latter being one of the most powerful nonaqueous solvents for lignin. Adsorption effects were known to be absent in this case, and the lignin molecules were considered to be unassociated in formamide. The four fractions were distinguishable with the formamide-G-100 system, thus indicating that the original fractionation was based on molecular size. The enzymatically liberated lignin contained molecules that comprised a continuum of molecular weights from approximately monomeric to molecules that were at the limit of the solvating power of dioxane-water (1:1) and dimethylformamide. Limited physicochemical data were consistent with a compact, approximately spherically symmetric shape of the lignin in solution.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Intrachain potential energy of the α-helix and of a coiled coil strand (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 189-197 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A comparison has been made of the intrachain potential energy of an infinite straight α-helix of poly-L-alanine with that of the distorted form adopted in a coiled coil conformation. The energy terms included were the van der Waal's, electrostatic, hydrogen-bond, and the rotational potential terms. The results indicate that the potential energies of the structures investigated are almost the same, and so a transformation from one state to another may occur without significant changes in potential energy. Particular care has been taken to ensure that the electrostatic and van der Waal's interaction terms are fully convergent. The values obtained for the α-helix were compared with those already published, and some significant differences were found.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Optical rotatory dispersion of mucopolysaccharides and mucopolysaccharide-dye complexes. II. Ultraviolet cotton effects in the amide transition bands (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 173-187 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ultraviolet optical rotatory dispersion curves of mucopolysaccharides exhibit particular Cotton effects in the spectral region of the n-π and π-π amide transitions. Two general patterns emerge: (1) enhancement of negative rotation and of the first negative Cotton effect (troughs 217-220 mμ) and (2) relative dominance of the positive Cotton effect in the π-π transition region (peak ∼198 mμ). Groups (1) and (2) can be correlated with a structural difference in the linkages of the amino sugars: (1) occurs with polymers containing 3-1-linked glycosamino sugars and (2) with glycosamino moieties linked 4-1 by either α- or β-glycosidie bonds. Measurements of the circular dichroic absorption bands support the qualitative conclusions from optical rotation. All mucopolysaccharides exhibit a first, negative band centered at 208-211 mμ, while only those in group (2) show, in addition, a positive band centered at 189-192 mμ. A suggested unifying model considers that difference in kind and/or degree of preferred geometry of the amide groups obtains from two forms of secondary order: (1) having a linear hydrogen bond from the N (acceptor) to the (C2)O - H of the preceding uronic acid and (2) having a linear hydrogen bond from the N (acceptor) to the (C2 or 3) O - H of the following sugar. The hydrogen bonds would have similar strength but opposite directions in two systems towards the nonreducing end (1) or towards the reducing end (2)], closing eight-membered rings
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Studies on the myosin molecule from smooth muscle (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 99-106 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The myosin molecule was extracted from the smooth muscle parts of horse esophagus and purified by ammonium sulfate fractionation. The schlieren pattern of the sedimentation velocity run showed a very sharp single peak of.5.9. S (s20,w). Molecular weight of the protein was measured by means of the Archibald and sedimentation equilibrium methods, both in 0.5M KCI buffered by 1/150 M phosphate at pH 7.5 and at 5°C. The values obtained were 6.25 × 105 and 5.81 × 105respectively, for the two methods. The second virial coefficients were 1.1 × 104 and 1.2 × 10-4 ml/g. Denatured smooth muscle myosin was prepared in a solution of 5M guanidine HC1 containing 0.4 M KC1 and 0.2 M β-mercaptoet hanol buffered at pH 8.0. The weight-average molecular weight of the denatured smooth muscle myosin was 2.24 × 105 and the second virial coefficient was 7.6 × 10-4 ml/g. The values described above are in good agreement with those reported for rabbit skeletal myosin with ammonium sulfate fractionation. The molecular dimension of the molecule is estimated as the value for an axial ratio of 100, assuming a rigid rod molecular model for this molecule, both the thermodynamical and hydrodynamical treatment being in a good agreement with this estimation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Masthead (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969) 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070401
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Conformation of polypeptide in the, helix-coil transition region (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 433-434 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No. Abstract
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070314
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Experimental thermodynamics of the helix-random coil transition. II. Calorimetric measurement of transition enthalpies of poly A in acid aqueous solution (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 423-431 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The enthalpy change accompanying the double helix-coil transition of polyriboadenylic acid (poly A) in aqueous solution has been measured optically and calorimetrically in the pH range 5.7-4.5. The course of this cooperative transition was followed optically by measuring changes in ultraviolet absorption as a function of temperature at different pH values, and calorimetrically by determining the heat capacity of the solution through the transition region. From the latter measurements, the enthalpy of transition was calculated. It is shown, that ΔH is dependent on pH as it is expected from the influence of protonation of the double helix of poly A.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070313
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Mechanical properties of poly(glutamic acid) in aqueous solution (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 453-458 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The interaction between ionizable carboxyl groups and the conformation of poly-(glutamic acid) (PGA) in aqueous solution were investigated by the mechanical method. The dynamic rigidity of the PGA solution has a maximum value at the pH corresponding to about 50% neutralization point. This may be due to establishing of a maximum attractive force by proton/charge fluctuation between ionizable carboxyl groups at that pH. The dynamic viscosity has a sharp change in the region of pH 5.5-6.5. It is suggested that this behavior is due to the helix-coil transition.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Proton relaxation in aqueous DNA solutions (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 447-452 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: By use of D2O we found that the shortening of the longitudinal proton relaxation time which occurs in the investigated aqueous yeast DNA solutions (≦ 2.4% with 2% protein) was not based on a hydration effect, but was caused by magnetic impurities only. An estimate shows that the mobility of the hydrated water molecules is reduced by less than two orders of magnitude in comparison with the free water molecules.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070403
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Method of determining the relative stability of different conformational states of biological macromolecules (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 435-445 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A general approach to the determination of relative stability of any pair of con-formational states of biological macromolecules or their complexes (in particular, to the determination of relative stability of native and disordered states of the macromolecule) has been suggested. For determining the free energy difference of the two states under the conditions when one of them is considerably more advantageous than the other, it is necessary for the macromolecule to be influenced by the transforming agent which levels free energies of both the conformational states, and to determine the external parameter derivative of the free energy difference in the region of the conformational transition induced by the change in this parameter. If the character of the dependence of this derivative on the external parameter (temperature, solvent composition, etc.) is known, then this allows the determination of the free energy difference of the two states under the conditions considered, even including conditions far from the transition region. The value of the derivative of the free energy difference in the transition region in many cases can be measured directly (in particular, when using calorimetry), while in cases when a direct measurement of the derivative is impossible, it can often he estimated experimentally from the steepness of the conformational transition. The methods of this estimation and also a possible character of the change of the considered derivative during variation of the external parameter are considered for the case when the transforming agent is one of the components of the solvent and, consequently, the derivative of the free energy difference is equal to the difference of number of molecules of this component hound with the macromolecule in two conformational states.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Heats of fusion of various amounts of absorbed water in wool keratin (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 459-474 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Wool-water systems, at water contents above a threshold value of 22.7 g of water per 100 g of wool keratin, yielded curves of specific heat against temperature showing peaks that are ascribed to the fusion of the absorbed water. Integral and incremental heats of fusion were obtained. Integral heats increase as the square of the water content above the threshold, and incremental heats follow a linear relationship. The incremental heat reaches a value of 55 cal/absorbed water, at the saturation water content, at 0°C of 33.9 g of water per 100 g of keratin. The state of the absorbed water is discussed. Clustering of water molecules takes place only above the threshold water content.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070405
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Raman spectroscopy of poly-L-proline in aqueous solution (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 173-179 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The laser-excited Raman spectra have been obtained of poly-L-proline in the solid and aqueous solution. In the solid state, the Raman spectra are of the form II which is the left-handed helical form with the peptide bonds in the trans configuration. Dissolution of this form in water produced only minor changes in the Raman spectra. The differences in frequencies produced by dissolving the polymer are associated with vibrational modes of the pyrrolidine ring as indicated by comparison with the Raman spectrum of L-proline. The similarity of the Raman spectra dictates that, the conformations of poly-L-proline chain are similar in the solid and aqueous solution.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Mise en évidence d'une relation entre la longueur el la constante de sédimentation des molécules de DNA en solution (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 181-185 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A comparative study on sonicated calf thymus DNA was made by using electron microscopy and sedimentation methods. The length distribution, established by electron microscopy by using Kleinschmidt's technique, is related to the sedimentation curve obtained with the same solution. The relation permits a determination of the sedimentation constant corresponding to a given length up to 8000 Å and vice versa.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Optical anisotropy of synthetic polynucleotides. II. Calculation of π-electron polarizability of uracil and adenine (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 199-216 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The π-electron polarizability of conjugated base molecules such as uracil and adenine are calculated semiempirically by using molecular orbital theories. The Hüekel method and the self-consistent-field (SCF) theory are used in the present calculation. The theoretical values obtained by the Hüekel method are consistently larger than the experimental results. The values obtained by the SCF theory are in good agreement with observed values. It is clearly demonstrated that the SCF method is better than the Hükel method for the calculation of polarizability. The polarizability of the adenine-uracil pair is calculated as the sum of the polarizabilities of adenine and uracil and also calculated by solving the eigenvalue problem for the A-U pair as an entity. The second method gives considerably larger polarizability than the first method. Discussions are presented and it is demonstrated that the second method is the correct way to calculate the polarizability of the A-U pair.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Reversibility of thermal transitions in proteins: Racemization and aggregation as factors in the reversible denaturation of a soluble keratin derivative (SCMKA) (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 187-198 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reversibility of the thermal denaturation of a low-sulfur fraction of solubilized wool keratin (SCMKA) has been studied under a variety of conditions of time, protein concentration, and pH. Two types of irreversibility for the transition have been encountered. One of these is associated with an aggregation of the protein on denaturation to give a product which may contain elements of a β conformation. This type of irreversibility is favored by high protein concentration, and the original conformation may in fact be regained if the aggregated structure is broken down by a solvent such as 8M urea and the urea subsequently removed by dialysis. The other type of irreversibility appears to be due to racemization of the protein. It does not seem to be dependent on protein concentration and is apparent only at temperatures beyond the actual transition range (∼40-65°C) at pH values below 11, At pH 12, however, racemization appears to proceed slowly even at 4°C. The thermal transition at pH 9 and pH 10 has been shown to be multistage in nature. Over the pH range 9-12 there is a progressive decrease in thermal stability with increase of pH. Addition of NaCl at pH 10 leads to an increase in thermal stability of the molecule.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Studies of the optical properties of the proflavine-DNA complex (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 217-235 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We report studies of the optical properties of the proflavine-DNA complex, using absorbance and circular dichroism spectroscopy. From comparison of the absorption spectra of proflavine complexed with calf thymus and T2 DNA, we conclude that stacking of the dyes external to the double helix is comparatively much weaker with T2 DXA, probably because of its glucosylation. Several sources are found for the circular dichroism induced in proflavine when it is complexed with DNA. There is a relatively weak circular dichroism induced when the dye is infinitely dilute on the DNA lattice; this presumably arises from the environmental asymmetry of the binding site. Stronger circular dichroism effects are induced by interaction of intercalated and stacked dyes; studies with T2 DNA, for which stacking seems to be blocked, permit a tentative resolution of effects due to the two modes of binding. One recurring theme of these studies is the observation that the optical properties are quite dependent on environment. The most dramatic example is a strong variation with salt concentration of the amplitude of the circular dichroism induced in the isolated (intercalated) monomer by the surrounding DNA. This suggests that the structure of the intercalated complex is quite sensitive to external conditions.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Binding of alcohols to the peptide CO-group of poly-L-proline in the I and II conformation. I. Demonstration of the binding by infrared spectroscopy and optical rotatory dispersion (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 237-246 
    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 n-butanol, benzyl alcohol, and trifluoroethanol to polyproline I (all peptide bonds in cis configuration) and II (all peptide bonds in trans configuration) has been demonstrated. It was found by infrared spectroscopy that hydrogen bonds are formed between the CO groups of the polymer and the OH groups of the alcohols. Their strength increases from n-butanol via benzyl alcohol to trifluoroethanol. The binding of benzyl alcohol could also be followed by optical rotatory dispersion due to the fact that the electronic transitions of the benzyl ring are rendered optically active by the binding to the polymer.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080209
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Helix-random coil phase transitions in polypeptide systems with random defects: A statistical mechanical model (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 259-274 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The statistical mechanics of the effect of a small number of randomly occurring defects on the melting of a polypeptide chain is developed by using a perturbation of Boltzmann factors technique. The method is illustrated by an example where a second-component impurity contributes more to the energy of the hydrogen-bonded superstructure of the polypeptide chain than does the dominant amino acid residue, resulting in the overall destabilization of the helical conformation.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080211
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Deformation behavior of erythrocyte ghost (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 275-287 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Biological membranes consist mainly of lipids and proteins. At present, the structure of the lipid phase appears to be established, but hypotheses on the molecular organization of the protein are difficult to support. Thus the deformation behavior of whole human erythrocyte ghosts, ghosts after the selective removal of lipids and ghosts stripped of lipids as well as nonlipid components have been examined in the hope of securing indirect information on the organization of the protein. It has been found that large localized deformations result in partial membrane failure and long uniformly wide fibrils, frequently in excess of 3000 Å, are drawn across the rupture. These data are interpreted in terms of currently favored membrane models and the possibility of a fibrous membrane framework consisting predominantly of protein is reviewed. The behavior of the membrane in its various stages of extraction is compared and contrasted to that of synthetic polymer films of known organization.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080212
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Helix-coil transition of poly-N5-(3-hydroxypropyl)-L-glutamine: Thermodynamic and statistical analysis (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 247-257 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermally induced conformational changes of poly-N5-(3-hydroxypropyl)-L-glutamine in water and in methanol-water (3:7 v/v) have been analyzed in terms of the Lifson-Roig theory. The transitions in both solvents can be described by using v = 0.017. The thermodynamic parameters for the random coil-to-helix transition of one amino acid residue at room temperature were found to be: in water, ΔH = - 130 cal/mole and ΔS = - 0.45 e.u.; in methanol-water (3:7 v/v), ΔH = - 170 cal mole and ΔS = - 0.45 e.u. The size distribution of helical segments is broad, and the results of numerical calculations are presented for three degrees of polymerization (DP = 100, 300, and 750).
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080210
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Extrinsic cotton effects of 9-aminoacridine bound to deoxyribonucleic acid and poly(α, L-glutamic acid) (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 289-292 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080213
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Molecular weight and dimensions of phycocyanin monomer and aggregates (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 293-295 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080214
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Molecular weight and shape of phycocyanin monomer and aggregates (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 297-299 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080215
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Equilibrium sedimentation of a polyelectrolyte in a density gradient of a low-molecular weight electrolyte. I. DNA in CsCl (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 303-304 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080217
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Cesium chloride density distributions in preparative equilibrium ultracentrifugation and computer program (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 301-301 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080216
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Nmr studies in solution of poly-L-proline (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969), S. 304-304 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080218
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Masthead (1969)
    New York : Wiley-Blackwell
    Biopolymers 8 (1969) 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360080301
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Optical activity of simple cyclic amides in solution (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 595-610 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The cyclic dipeptide, L-alanylglycyl anhydride, has been studied by optical rotatory dispersion; both L-alanylglycyl anhydride and the lactam, L-3-aminopyrrolidin-2-one, have been studied by circular dichroism. In hydroxylic solvents the circular dichroism spectra of 3-aminopyrrolidin-2-one can be attributed to an n-π* transition near 220 mμ and a π-π* transition near 190 mμ. In these solvents the optical activity of L-alanylglycyl anhydride can be explained as being due to contributions of n-π* transitions and a split π-π* transition. In acetonitrile, however, the circular dichroism spectrum of 3-aminopyrrolidin-2-one shows an additional apparent minimum near 200 mμ. The CD spectrum of the dipeptide is also quite distinctive in this solvent. The possible nature of the band at 200 mμ and the implications of these findings are discussed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070415
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Interaction between DNA and the polybases polyarginine and polylysine in equivalent precipitates (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 619-623 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070418
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Masthead (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969) 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070501
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Backbone conformation of amino acidsContribution No. 260 from the Centre of Advanced Study in Biophysics, University of Madras, Madras-25, India. (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 624-626 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070419
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Flow birefringence and intrinsic viscosity of a T2 bacteriophage DNA-methylated bovine serum albumin complex (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 627-648 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The flow birefringence, extinction angles, and intrinsic viscosity have been determined at low velocity gradients for a complex of T2 bacteriophage DNA and methylated serum albumin prepared in dilute solution to a stoichiometry of approximately 90 proteins per DNA molecule. Comparative data upon equivalent solutions of pure uncomplexed T2 DNA are also presented, and these data are completely in accord with the results of previous study. The experimental data are interpreted in terms of current dynamical theory and indicate that the complex has an essentially linear chain structure, consisting of approximately two DNA molecules, which is hydrodynamically indistinguishable from the pure DNA and that extensive internal or intramolecular binding in the complex does not occur. Although interpretation of the results is hampered by an apparent moderate degree of polydispersity in the complex preparations and by relatively large shear extrapolations, the data for both DNA and the complex are substantially in accord with dynamical theory for a nondraining bead subchain model having high kinetic segmental rigidity.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070502
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Far-infrared spectra of poly(-α-amino acids) with basic alkyl group side chains (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 649-658 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Far-infrared spectra in the region from 700 to 60 cm-1 have been measured for the α-helix structures of poly(L-α-amino-n-butyric acid), poly-L-norvaline, poly-L-norleucine, and poly-L-leucine and for the β-form structures of poly(L-α-amino-n-butyric acid), poly-L-valine, poly(DL-amino-n-butyric acid), poly-DL-norvaline, and poly-DL-norleucine. The changes of the spectra on N-deuteration have been measured in the region between 700 and 400 cm-1. It is concluded that, the α-helix has characteristic bauds near 690, 650, 610, 380, 150, and 100 cm-1, and that the β-form has characteristic bands near 700, 240, and 120 cm-1. The main-chain vibrations in the region from 600 to 200 cm-1 are strongly coupled with the side-chain deformation vibrations.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070503
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Matching of single-strand breaks to form double-strand breaks in DNA (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 681-693 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Single-strand breaks (ssb) in opposite strands of DNA can be sufficiently near that a double-strand break (dsb) results. A theory is presented by which the maximum number h of base pairs which cannot prevent double-strand breakage can be determined from the rates of production of ssb and dsb. The assumptions required to derive the necessary equations as well as the range of validity of the equations are discussed in detail. In the experiments ssb and dsb were produced by x-irradiation in buffers which do not eliminate indirect effects and were measured by analytical ultracentrifugation. Values of h have been determined in low and high ionic strength and in low ionic strength over a range of temperatures. The values, 2.64 and 15.8, were obtained for high and low ionic strength, respectively.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070506
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Studies of a specific association between acriflavine and DNA in intact cells (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 695-705 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The nature of a specific association between acriflavine and cellular DNA was investigated by subjecting the DNA of intact cells to denaturation, ultraviolet radiation, and base analog substitution. The predictable modifications of DNA structure were then correlated with the quantitative alterations in dye adsorption by the cells. It was concluded that, under experimental conditions of limited dye availability, the bonding of dye was restricted to sites of highest bonding affinity. These were shown to be situated between adjacent thymine molecules on a single strand of DNA. The 5-methyl groups of thymine may endow the bond with its specificity.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070507
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Interactions des ions métalliques avec le DNA. I. Comportement de polyélectrolyte et liaison des ions compensateurs (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 659-670 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The theory of polyelectrolyte solution of Alexandrowicz: and Katchalsky is used to calculate the electrostatic potential of single stranded polynucleotides for different ionic strength. We have considered the potential of double stranded DNA as the superposition of the different potentials produced by each chain, provided the average distance between the strands is higher than an ionic strength-dependent parameter b. For ionic strength lower than 5 × 10-2M, the assumption is no longer valid, and a cylindrical model with a uniform charge density must be used. The continuity between the two models was tested, and thus we can calculate the electrical potential at the vicinity of a phosphate group in the whole range of ionic-strength where the double helix is stable. It was therefore possible to determine the theoretical number of ions bound electrostatically to DNA and we found an increase of ion binding with a decrease of ionic strength. Such a model was further applied to the change of specific volume in different salt solutions. Comparison is made with recent pycnometric data on Na- and Cs- salts of DNA. Agreement is good in the case of Cs+, but for Na+, cation binding is likely to be accompanied by a change of the hydration of DNA, which depends on ionic strength. With the same model we can see easily the ion-trapping properties of DNA which play an important role in any formation of complex between heavy ions and bases.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070504
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Interaction des Ions Métalliques avec le DNA. II. Adsorption préférentielle de l'Ion césium par les Acides nucléiques (1969)
    New York : Wiley-Blackwell
    Biopolymers 7 (1969), S. 671-680 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preferential adsorption of cations occurs in the solvated shell surrounding polyanions, especially polynucleotides and nucleic acids. The solvation parameter Γ is determined from sedimentation coefficients which are considered as pienometric determinations of the specific volume of the sample. By comparing two identical concentrations (0.1M) of monovalent salts, NaCl and CsCl, and using the model of DNA described in the preceding paper, one can relate the ratio SCs/SNa to solvation parameters ΓCs, and ΓNa.On the other hand, Γ can be related to the difference of energy W, between cation and water, to be extracted from the solution and placed in the vicinity of the polyanion. One finds generally a preferential solvation of the polarizable caesium ion by means of London-van der Waals interactions with bases. With reasonable assumptions, an estimate of W can be made, and the predicted value of Γ can be compared to the experimental one. An average of six sites is found around each base in a single-stranded polymer, but-only one in the double-stranded structure. The amount of secondary structure can thus be estimated from the simple measurement of the ratio of two sediment constants.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1969.360070505
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Morphological, ultrastructural, histochemical and electrophoretic studies on the venom system of Nasonia vitripennis walker (hymenoptera: Pteromalidae) (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 127 (1969), S. 177-203 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The venom system of Nasonia vitripennis is well-developed and composed of an unbranched acid gland and associated reservoir. Fine-structural, histochemical and electrophoretic studies indicate that the venom is produced by two protein-secreting epithelia. The bulk of the venom is synthesised in the columnar cells of the acid gland and discharged via “vesicular organelles” and the efferent ductular system into the lumen of the reservoir. The acid gland also contains squamous chitogenous cells, situated either around the central lumen or interposed between the bases of the columnar cells. Once within the reservoir, the venom is probably activated by enzymatic secretions from the reservoir secretory cells. Each of these cells has a “vesicular organelle” but, in contrast to the columnar cells of the acid gland, the cytoplasm contains a preponderance of free ribosomes, and protein segregation apparently occurs outside the Golgi complexes.The venom is expelled through the efferent discharge duct by muscular contractions, which open the duct lumen and bring it into contact with the funnel of the ovipositor. Excessive distortion of the duct is prevented by a massive ventral ligament.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051270205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Electron microscopic studies of the compound eye of the toadbug, Gelastocoris oculatus (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 127 (1969), S. 233-257 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: There are eight retinula cells in the ommatidium of the compound eye of the toadbug (Gelastocoris oculatus), two of which are central in position. Along the axial sides of the six peripheral retinula cells expand six cytoplasmic processes from the apical crystalline cone cells. These processes, which contain longitudinally-oriented microtubules, are associated with all eight retinula cells by means of desmosomal junctions. In addition to providing structural support, the possibility is set forth that the interconnecting cone processes might also serve to functionally integrate the retinula cells of an ommatidium. The eight retinula cells possess microvillus surfaces, which are especially prominent in the six peripheral cells, where they extend into the lumen of the ommatidium. There is evidence of pinocytotic activity at the bases of microvilli. Multivesicular bodies are present in the cytoplasm of retinula cells, and the means by which these bodies might be elaborated are discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051270208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    On the mechanism of respiration in the bullfrog, Rana catesbeiana: A reassessmentSupported (in part) by National Science Foundation grant GB-6521X. Presented (in part) at the 150th Conference of the Society for Experimental Biology in Bristol, England, during March 1968, at the meeting of the American Society of Ichthyologists and Herpetologists at Ann Arbor, Michigan on 18 June 1968, and before the Society for the Study of Amphibians and Reptiles meeting at Mountain Lake, Virginia on 24 August 1968. (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 127 (1969), S. 259-289 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The mechanism of respiration in the bullfrog has been analyzed by means of pressure recordings from the buccal cavity, the lungs and the abdominal cavity, by cinematography and cinefluorography, and by electromyography of buccal, laryngeal and abdominal muscles. Gas flow was investigated by putting frogs in atmospheres of changing argon and nitrogen content and monitoring the concentration of the nostril efflux.Three kinds of cyclical phenomena were found. (1) Oscillatory cycles consist of rhythmical raising and lowering of the floor of the mouth, with open nares. They have a definite respiratory function in introducing fresh air into the buccal cavity. (2) Ventilatory cycles involve opening and closing of the glottis and nares and renewal of a portion of the pulmonary gas. More muscles are involved and the pattern of muscular activity is more complex than in the oscillatory cycles. (3) Inflation cycles consist of a series of ventilation cycles, interrupted by an apneic pause. The intensity of the ventilatory cycles increases before this pause and decreases immediately thereafter. This results in a stepwise increase in pulmonary pressure, to a plateau (coincident with the pause) followed by a sudden or stepwise decrease.The respiratory mechanism depends on the activity of a buccal force pump, which determines pulmonary pressure whose level is always slightly less than the peak pressure values of the ventilation cycles. The elevated pulmonary pressure is responsible for the expulsion of pulmonary gas during the second phase of the next ventilation cycle. This pressure is maintained by the elastic fibers (and the smooth masculature) of the lungs.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051270302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Tentacular and oral-disc regeneration in the sea anemone, Aiptasia diaphana. I. Sequential morphological events in distal-end restitutionThis work was supported by National Science Foundation grant GB-5045 and National Institutes of Health Bio-Medical Sciences Support grant to NYU. (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 127 (1969), S. 373-381 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The complete regeneration of a new oral-disc and tentacles has been observed and described for Aiptasia diaphana. These structures are regenerated quite rapidly: seven to ten days at 20°C. At three days post-amputation, the new primary, secondary, and tertiary tentacle buds begin to develop in direct association with the underlying primary, secondary, and tertiary septae (respectively) of the column, suggesting that the latter organize the form of the regenerating oral-disc. Two days after amputation, the zooxanthellae of the presumptive oral disc arrange themselves into a ring which quite precisely delimits the area from which the tentacle buds will form. In spite of its suggestive proximity, this accumulation of algae plays no role in the induction of tentacle buds as was shown by studying regeneration in anemones which essentially lacked large quantities of these symbiotic algae.Cuts perpendicular to the longitudinal axis of the column result in an equal rate of tentacular regeneration around the entire circumference of the presumptive oral disc. Oblique amputations foster an asynchronous regeneration: the tentacle buds of the distal-most area of the severed column are larger and regenerate much sooner than those of the proximal region. Similar results were obtained by studying anemones which were cut perpendicular to their longitudinal axes at different levels along the column. The data suggest that an oral-aboral gradient exists concerning the time required for the initiation of tentacle budding and the rate of tentacle regeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051270308
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Masthead (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 128 (1969) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051280101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    A rapid method for detecting malformations in rat fetusesSupported in part by National Heart Institute Graduate Cardiovascular Training grant 2T1-HE 5493 (Dr. Barrow, Trainee) and by grants from the North-east Florida Heart Association, Inc., and the Palm Beach Heart Association, Inc., Chapters of the Florida Heart Association, Inc. Read before the Teratology Society, Estes Park, Colorado, May, 1967. (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 127 (1969), S. 291-305 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A rapid method for examining rat fetuses is presented. The technique consists of fixing the fetuses in Bouin's solution, serially sectioning the head, neck and lower trunk with a razor blade and doing sagittal sections of the heart after opening the thoracic cavity. Examples of sections from normal 20 day rat fetuses are given as well as some with the following abnormalities: cleft palate produced by chlorcyclizine and eye and heart malformations resulting from anti-adult rat kidney serum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051270303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    The structure of an epidermal cell during the development of the protein epicuticle and the uptake of molting fluid in an insect (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 127 (1969), S. 7-39 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A structure for a generalized insect epidermal cell during the formation of the epicuticle is proposed, based on studies of several different epidermal cell types. The protein epicuticle is defined as the dense homogeneous layer below the cuticulin. The formation of the protein epicuticle involves secretory vesicles arising in Golgi complexes, and marks an interlude in the involvement in cuticle formation of plasma membrane plaques. The plaques are concerned in cuticulin formation before and in fibrous cuticle formation after the deposition of the protein epicuticle.The epidermis is characterized by the possession of a cytoskeleton of microtubules and a matrix of microfibers. In the elongated cells forming bristles and spines, the microfibers are often oriented in bundles with an axial banding which repeats every 120 Å. The microtubules are also arranged in columns with a trigonal packing and center to center spacing of about 800 Å. These cytoskeletal structures separate the other organelles into channels which may restrict the pathways open for the movement of secretory and pinocytotic vesicles. The protein epicuticle arises from the secretory vesicles which discharge at the apical surface. The contents disperse and reaggregate below the cuticulin. The Golgi complexes in the basal and central regions have many secretory vesicles and a small saccular component, differing from those nearer the apex which are smaller and have fenestrated saccules. The small coated vesicles (800 Å in diameter) associated with both sorts of complex, probably move to the apical and basal faces of the cell where they may give rise to the large coated vesicles (2000 Å in diameter) inserted in the plasma membrane. Pinocytosis occurs from both apical and basal faces but most lytic activity is in the apical region. Plant peroxidase injected into the haemocoel is taken up basally and transported to the apical MVBs. The large coated vesicles on the apical face may be concerned in the control of the extracellular subcuticular environment. They appear to fill up and detach, fusing to become the apical MVBs.
    Additional Material: 24 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051270103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    The cytology of submandibular glands of the opossumThis study was supported by U.S.P.H.S. grants DE 02110 and DE 02670. (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 128 (1969), S. 1-33 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Submandibular glands of the opossum have been studied by light and electron microscopy and compared with other mammalian salivary glands. The glands have four parenchymal segments which connect in the order named below to convey saliva toward the oral cavity. 1Secretory units are elongated branching tubules exhibiting mucous and special serous cell types. Mucous cells predominate and resemble those in other salivary glands. Special serous cells differ from “typical” serous cells. They contain a preponderance of tubular or vesicular endoplasmic reticulum and secretory granules which vary from electron lucent to electron opaque.2Intercalated ducts are short segments lined by nonsecretory, cuboidal cells.3Striated ducts are numerous and lie in the center of the lobule. The duct epithelium has four cell types, designated light cells, dark cells, Type I basal cells, and Type II basal cells. Light cells possess basal infoldings associated with mitochondria, but the other cell types lack this characteristic.4Excretory ducts are also lined by four cell types which bear the same names as those of striated ducts. Three of the four cell types are virtually identical to those of striated ducts, but light cells differ. They do not always contain basal infoldings and the supranuclear cytoplasm lacks distinct inner and outer zones.The glands resemble salivary glands of higher mammals in many respects while possessing certain unique cytological features which may reflect the secretory needs of the organism.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051280102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Morphologic variation in the cranium and mandible of the white-tailed deer (Odocoileus virginianus): A comparative study of geographical and four biological distances (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 128 (1969), S. 95-112 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Several biological distances based on cranial and mandibular variation among breeding groups of white-tailed deer were calculated and compared with geographic distances among the groups. Distances based on epigenetic variation among ten groups were calculated using 16 non-metric variants of the cranium and mandible. Penrose's size and shape distances and Mahalanobis' D2 distance were calculated for 11 groups; the calculations were based on seven skeletal and seven dental metric variables of the mandible.The biological distances were correlated with geographic distance as follows: the epigenetic distance, 0.74; Penrose's shape distance, 0.71; Penrose's size distance, 0.45; and Mahalanobis' distance, 0.37. All correlations were significant at the 0.01 level. The epigenetic and Penrose shape correlations were significantly higher than the Mahalanobis correlation.Because of the conditions under which the breeding groups were selected, it was assumed that genetic affinites among the groups would be a function of geographic distance. The results suggest that the epigenetic distance and Penrose's shape distance reflect genetic affinities among groups better than do the Penrose size and Mahalanobis distances.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051280105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Mechanics of respiration in the snapping turtle, Chelydra serpentina (Linné) (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 128 (1969), S. 195-227 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The mechanism of lung ventilation in chelonians has been much debated. Electromyographic studies show that the basic mechanism in the snapping turtle, Chelydra serpentina, is dependent on the activities of four major respiratory muscles that are capable of varying the volume of the visceral cavity. The precise mechanism utilized varies in response to environmental factors, especially the depth to which the animal is submerged. Chelydra tends to reduce muscular activity to a minimum, and hydrostatic pressure or gravity replaces muscular effort whenever possible. The response is subject to hysteresis. Both the mechanics and pattern of ventilation in Chelydra differ from those of Testudo. The differences appear to be attributable in part to Chelydra's markedly reduced plastron and more extensive respiratory musculature and in part to the different habitats occupied by the two species.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051280205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Cytological observations on the so-called neoblasts in the serpulid SpirorbisThis work was supported by a Faculty Research grant from the Graduate Council of the University of Massachusetts. (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 128 (1969), S. 241-259 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The purported “neoblasts” of the serpulid Spirorbis have been studied in Spirorbis (Paradexiospira) vitreus and Spirorbis (Laeospira) borealis at both the light and electron microscopic levels. These perivasal cells occur in greatest abundance around the ventral blood vessel of the achaetous region. In light microscope preparations, the perivasal cells are intensely basophilic, containing basally situated nuclei, and relatively large nucleoli. The fine structure of the perivasal cells reveals that they contain an abundance of rough endoplasmic reticulum, well-developed Golgi complex, heterogeneous dense bodies, and cytolysomes. The respiratory pigment chlorocruorin, which has a diameter of about 230 Å and is believed to be composed of two superimposed hexagonal components, has been localized within: cisternae of the rough endoplasmic reticulum, elements of the Golgi complex, and membrane-bounded vesicles at the base of the perivasal cells. Evidence is advanced which strongly suggests that molecules of chlorocruorin are transported from the perivasal cells into the lumen of the vessel by reverse pinocytosis. It is concluded that whatever other functional role(s) the perivasal cells of Spirorbis may have, a major function is the synthesis and secretion of chlorocruorin. Whether the perivasal cells can be considered to be pluripotent is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051280207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Functional components versus mechanical units in descriptive morphologyPresented (in part) before the annual meeting of the Section of Vertebrate Morphology, American Society of Zoologists, on December 30, 1968 at Dallas, Texas. (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 128 (1969), S. 365-368 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The concept of functional components was initially proposed by van der Klaauw ('45, '52) to indicate overlap of functional influences particularly in mammalian skulls; his analysis marked a departure from the study of single characters to that of function-modified systems. A very similar set of terms is now coming into vogue to describe the mechanically separable components of highly kinetic fish, amphibian and reptilian skulls. In these cases the term functional unit often pertains only to the musculo-skeletal system and is utilized during the process of description; it is often applied before a complete functional analysis has been carried out.Yet, any structure tends to be affected by the influence of multiple functions, and any function will almost certainly affect multiple characteristics of the animal. Since functional components overlap, the term should not be used to label an essentially topographical dissection of the animal. It cannot be expected that each loosely connected component of a kinetic skull subserves as a single “function,” and that this function does not overlap onto other units.It is suggested that the term mechanical unit be substituted as a label for the mechanical sub-divisions often utilized to organize descriptions. The concept of functional units in the original sense then remains available as an analytical tool.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051280305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    The cytology of the vitellogenic stages of oogenesis in Drosophila melanogaster. I. General staging characteristics (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 128 (1969), S. 427-441 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cytology of the vitellogenic stages in the development of the oocyte of Drosophila melanogaster has been studied using whole mounts and sections of plastic-embedded ovaries and single egg chambers for light microscopy and cytochemistry. The migrations, changes in morphology, and synthetic products of the follicle cells are described as a function of developmental stage. The follicle cells synthesize the egg coverings, the vitelline and chorionic membranes, and elaborate the micropyle and dorsal chorionic appendages. The changing structure of the nurse cell nucleus and changes in organelle composition of its cytoplasm are described. The nurse cells synthesize ribosomes, lipid droplets, and mitochondria. These components pass through the ring canal system into the oocyte, which increases in volume some 200,000 times during its 78 hours of development.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051280404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Musculature, nervous system and glands of metasomal abdominal segments of the male of Nomia melanderi Ckll. (Hymenoptera, Apoidea)Supported by Grant 12-14-100-8072(33) from Agricultural Research Service, USDA. (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 129 (1969), S. 59-79 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Each muscle of the third metasomal segment of the male of Nomia melanderi Ckll. is described in detail. The points of attachment of each muscle are compared with their homologs in other pregenital segments and with their homologs in the female. The function desgnated for each muscle describes its action alone or in conjunction with other muscle(s). New names are given to genital muscles by referring in the name to their points of attachment. Each intratergal muscle has homologous points of attachment in the pregenital segments of both sexes. The median tergo-dorsoplical muscle of the seventh segment and the oblique tergo-dorsoplical muscle of the eighth segment have changed their points of attachment. The intrasternal muscles are modified to suit the needs of courtship and mating, thus they are different from their homologs in the female. The spiracular muscles are well developed in all segments except the eighth, where the sterno-spiracular muscle is absent. The extrinsic genital muscles are derived from the intrasternal muscles of the eighth and ninth segments. The parameral and volsellar muscles are reduced in number. The aedeagal muscles, except the aedeago-phallic, have retained similar points of attachment to those found in primitive Hymenoptera. The topography of the metasomal nervous system is reported in detail by following each nerve and nervule to its termination. The study shows that (at least in Nomia) the criterion of nerve-concentration should not be used alone to indicate evolutionary levels. To accommodate the morphological changes in the terminal segments the Anterior and Posterior Lateral Nerves have migrated to new locations. The pattern of nerve topography (even at the nervule level) is homologous both in the different pregenital segments and between the sexes. The fact that homology does not exist between the external genitalia of the male and the modified ovipositor of the female supports the thesis that the male genital capsule is of phallic rather than prephallic origin. A pair of intersegmental membrane glands located between the seventh and eighth sterna is described. These glands may be the source of a pheromon responsible for gregariousness among “sleeping” males.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051290105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Ultrastructure of thymic myoid cellsThis investigation was supported in part by National Science Foundation grant GB-6984 and U.S.P.H.S. grant FR-05423. (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 129 (1969), S. 201-210 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Mature myoid cells in the parenchyma of reptilian thymus contain all the organelles typical of striated muscle. The presence of both immature and degenerating stages indicates a turnover of myoid cells in the adult thymus. In the earlier stages of differentiation myoid cells resemble thymic epithelial cells. A close parallel exists between developing myoid cells, skeletal muscle differentiating in vitro, rhabdomyoma and rhabdomyosarcoma. Elaborate lattice-like structures are formed by transverse tubules. These structures are compared with similar configurations which have been described in muscle and mitochondrial cristae.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051290205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    The hatching thread of praying mantids: An unusual chintinous structure (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 129 (1969), S. 307-315 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The hatching threads of praying mantis embryos are silk-like in appearance, but cellular in origin. Their development can be divided into four phases. In phase 1 each embryonic cercus produces a hollow column of cells which is pushed out dorso-laterally, on either side of the embryo, between the epidermis and the chorion. In phase 2 each column becomes transformed into an unbroken helical cellular filament. The terminal five or six cells at the distal end of each filament become permanently attached to the inner surface of the chorion. The cellular arrangement of the filament is superseded by an apparent syncytial condition. In phase 3 the extensive proximal parts of the two filaments become folded into a compact space, flanked by the cerci and styli, at the tip of the abdomen. Throughout phase 4 the filaments remain in two tightly coiled groups, connected to the chorionic attachments by loosely coiled distal regions. Progressive secretion of chitin by, and around, each filament forms a sheath, 1-2 μ thick, which provides the tensile component of the hatching threads. During emergence these threads become unravelled to form a double thread which allows the insect to hang from the ootheca and complete its first ecdysis.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051290304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Masthead (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 129 (1969) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051290401
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    The influence of the nerve on lower jaw regeneration in the adult newt, Triturus viridescensPortion of a thesis submitted to the Graduate School of Case Western Reserve University in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Anatomy.,This investigation was supported by grants GM 08580-07 and GM 12653 from the National Institutes of Health. The work was performed while the author held a pre-doctoral fellowship from the National Institutes of Health. (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 129 (1969), S. 401-413 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The present investigation was undertaken in an attempt to determine the role played by the nerve in the regeneration of the lower jaw of the adult newt, Triturus viridescens. The results indicated that the number of nerve fibers normally available at the amputation surface was very low compared with that of the newt forelimb. Furthermore, denervation of the lower jaw reduced the number of nerve fibers available to an extremely low level and maintained the number at a low level for up to four weeks without intervening redenervations. The regenerative events in the denervated and amputated lower jaws were indistinguishable histologically from those in amputated jaws having normal innervation. This presented an apparent exception to the general rule that regeneration of external body parts is dependent on the nerve. Several possible explanations are proposed by which this apparent exception might be explained. The process following amputation might be an exaggerated form of wound healing and tissue regeneration which can occur in the absence of nerves. The tissues of the lower jaw might be more sensitive to the influence of those nerve fibers present. The nerve fibers themselves might be qualitatively different and thus exert a greater influence on the tissues.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051290403
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    A comparative study of the embryological development of the median cord in hemipteraAuthorized for publication on September 11, 1968 as paper No. 3476 in the journal series of the Pennsylvania Agricultural Experiment Station. (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 129 (1969), S. 375-399 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Median cord development is uniform in six families of Hemiptera and five non-hemipterans. The median cord arises independently from the lateral cords and is histologically distinguishable from the latter throughout development. Intrasegmentally, median cord nuclei possess prominent nucleoli and many small chromatin granules surrounded by clear nuclear sap. This region forms what appear to be glial elements at the midline of the neuropile. Intersegmentally, a spherical clump of eight to twelve large nuclei develops surrounded by dark-staining granular cytoplasm. Each intersegmental clump migrates anteriorly into the preceding ganglionic region but degenerates soon after katatrepsis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051290402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Sequence of ossification in the skeleton of growing and metamorphosing tadpoles of Rana pipiensSupported by research grants from the National Science Foundation (GB 4317) and the U. S. Public Health Service (GM 05867-10). (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 129 (1969), S. 415-443 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The order of ossification of bones in the skeleton of Rana pipiens during larval growth and metamorphosis has been determined from observations on specimens fixed in 70% alcohol and stained with alizarin red S. The axial skeleton ossifies in a generally cephalo-caudal sequence, beginning with the parasphenoid bone at Taylor-Kollros stages IV-IX, followed by vertebrae (V-IX) and then the urostyle (IX-XIV). Exoccipitals (VII-IX), frontoparietals (XI-XII) and prootics (XIII-XVII) are additional cranial bones which successively ossify before metamorphosis. With the onset of metamorphosis at stage XVIII jawbones and rostral bones of the skull ossify in the following succession: premaxilla, maxilla, septomaxilla, nasal, dentary, angular, squamosal, pterygoid, prevomer, mentomeckelian, quadratojugal, palatine, columella, posteromedial process of “hyoid.” The sphenethmoid does not ossify until after metamorphosis.Ossification of limbbones begins with the femur or humerus at stages X-XII and progresses proximo-distally to the phalanges by stages XIII-XV. Carpals, however, do not ossify until stage XXV or after metamorphosis. The ilium of the pelvic girdle begins to ossify at stages X-XII, but the ischium is delayed until stages XX-XXIII. Scapula and coracoid of the pectoral girdle undergo initial ossification at stages XII-XIV, suprascapula and clavicle at stages XIII-XV. The sternum does not begin to ossify until stage XXIV. The possible role of thyroid hormones in stimulating osteogenesis is discussed.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051290404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Cell proliferation in Xenopus tissues: A comparison of mitotic incidence in vivo and in organ culture (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 127 (1969), S. 363-372 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Using the Colcemid technique, the mitotic incidence (MI) was measured in the epidermis, lung, spleen, liver, kidney and ovarian follicular cells of metamorphosed, immature Xenopus laevis laevis. The MI was higher at 25°C than at 20°C, and there was a significant ranking correlation between organs in respect of the MI in different animals. With the exception of the liver and kidney, organ cultures showed good preservation for up to six days in vitro using a medium supplemented with 10% fetal calf serum, and values for MI comparable with or even higher than in vivo were obtained.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051270307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Masthead (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 127 (1969) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051270401
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Ultrastructure of bovine parotid glandsSupported by U.S.P.H.S. grants DE 02670 and DE 02110. (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 127 (1969), S. 453-473 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Bovine parotid glands exhibit outstanding structural differences when compared with those of non-ruminant mammals. The acini are tortuous, branched and lined with cells of different heights, imparting a scalloped appearance to acinar lumina. Numerous microvilli, ca. 1.5 μ in length, extend into the lumina and intercellular canaliculi. Intercellular canaliculi measure ca. 3 μ in diameter and interweave in close association with intercellular tissue spaces. Intercellular tissue spaces are separated from the extraacinar spaces across a basal lamina only, whereas junctional complexes guard canaliculi from direct continuity with tissue spaces and/or extraacinar spaces. Flattened cytoplasmic lamellae extend from adjacent acinar cells and loosely interdigitate with one another across the tissue spaces. Acinar cells contain more mitochondria and less granular endoplasmic reticulum than parotid glands of non-ruminant mammals. Two types of secretory material, in the form of inclusions which vary in size and electron density, are present in the acinar cells. Intercalated ducts connect acini with striated ducts which in turn, empty into collecting ducts located between gland lobules. In terms of frequency of “basal infoldings” and numbers of mitochondria, striated ducts of calf parotid glands are not as well developed as those of certain other salivary glands. Myoepithelial cells are most often present at junctions of acini and intercalated ducts where they may attach to both acinar and ductal epithelium. Nerve “terminals” were not observed on the epithelial side of basement membranes in relation to the secretory cells.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051270406
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Rheo-optical studies of high polymers. XIV. Study of the deformation mechanism in polymer blends of polypropylene with ethylene-propylene rubber (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 171-182 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: To clarify the deformation mechanism in polyblends of polypropylene with ethylene-propylene rubber having different compositions, simultaneous measurements of the infrared dichroism with stress and strain under a constant rate of strain of 1.64%/min have been carried out. The orientation function of the crystallographic c axis of polypropylene in the blends has been obtained as a function of strain ranging from 0 to 20% and of polypropylene content ranging from 0.3 to 1.0. These results have been compared with the temperature dependences of the dynamic Young's modulus and of the loss modulus, as well as of stress-strain curves for the same blends. The modulus data analyzed by Kerner's equation reveal the occurrence of phase inversion at polypropylene contents higher than about 0.5, and this is supported by the infrared dichroism data. The strong effect of quenching on crystalline structure and mechanical properties of pure polypropylene has also been elucidated.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Cyclic stress-strain behavior of the dry polycarbonate craze (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 183-200 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Equipment and methods have been developed which allow photomicrographic determination of the stress-strain properties of the individual craze. Serial cyclic tensile tests on polycarbonate crazes are described. Under stress the typical dry polycarbonate craze thickens solely by straining; no adjacent polymer of normal density is converted to craze material. The craze exhibits a yield stress followed by a recoverable flow to roughly 40-50% strain at 6000-8000 psi. On return to zero stress the craze exhibits creep recovery at a decelerating rate. The yield stress and loss factor of each cycle decrease with increasing initial strain and cycles initiating at 50% strain or more show completely Hookean behavior. Creep recovery results in recovery of yield stress and loss factor also. Craze tensile behavior is suggested to be essentially an extension of the craze formation process. Decrease in elastic modulus and yield stress with increasing strain are rationalized in terms of strain-produced decrease in density and resultant increase in stress concentration factor on the microscopic polymer elements of the craze. Polymer surface tension and the large internal specific surface area of the craze are suggested to be important factors in the large creep recovery rates of the craze.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Derivation of distributions of the degree of polymerization by probability theory (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 241-248 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A method of determining distributions of the degree of polymerization by means of probability theory is derived. This method, based on Kolmogorov's forward differential equation, is illustrated by application to two familiar kinetic schemes and is used to derive the distribution of degree of polymerization for free-radical polymerization with diffusion-controlled termination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070120
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Effect of birefringence on low-angle light-scattering patterns from oriented polymer films (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 271-278 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effect of birefringence of a polymer film upon its photographic light-scattering pattern is considered for the case of a single, anisotropic, two-dimensional spherulite imbedded in a birefringent matrix. It is shown that for the case of a polarizer and analyzer crossed at +45° and -45° to the analyzer, the scattering pattern is modified in a manner agreeing with experimental observation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Unperturbed dimension of poly-N-vinylcarbazole (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 285-295 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Osmotic-pressure, viscosity, and light-scattering measurements have been carried out on dilute solutions of poly-N-vinylcarbazole fractions (4 〈 10-4M 〈 230) in toluene, dioxane, and benzene. The theta temperature for poly-N-vinylcarbazole in toluene solutions has been found to be 37 ± 1°C. The intrinsic viscosity of poly-N-vinylcarbazole in toluene at 37°C is represented by [η]θ = 76.2 × 10-3M̄n0.50. Values of the characteristic ratios (〈L2〉0/M)1/2 and σ = (〈L2〉0/〈L2〉0f)1/2 have been obtained as 633 × 10-11 and 2.85, respectively. It appears that the large σ value is due to the steric repulsion between large side groups.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Mechanical relaxation in polypropylene as a function of polymorphism and degree of lamella orientationThis paper was presented in part at the annual March meeting of The American Physical Society, Chicago, Illinois, March 27-30, 1967. (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 389-404 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Mechanical relaxation data as a function of temperature (ca. 1 Hz) have been obtained for several samples of isotactic polypropylene crystallized from the melt, which exhibit both α and β forms as well as varying degrees of lamella orientation. The samples ranged in morphology from an unoriented sample showing only the α form to one highly oriented having approximately 90 per cent the β form. Results for the logarithmic decrement Δ and loss modulus G″ are that the low temperature (ca. -75°C) and glass temperature (ca. 0°C) relaxations show little or no sensitivity to orientation in the α form, but that the intensity of the two processes is different in the α form than in the β form for samples of nearly equal overall per cent crystallinity. In both Δ and G″, the low-temperature peak decreased and the glass temperature peak increased in intensity as the fraction of β form crystallinity present increased. Data for the high-temperature relaxation (ca. 80°C) indicate a dependence upon orientation and/or crystal form in addition to a dependence upon per cent crystallinity.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070210
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Polyamides in solution. III. Viscometry of linear polycaprolactam (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 411-422 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The viscometric behavior of linear polycaprolactam has been studied in the absence of the electroviscous effect in aqueous solvents containing 85% and 64.5% formic acid and in trifluoroethanol, as a function of temperature and also under unperturbed conditions. Results are discussed in terms of the existing theories; in particular, the negative temperature coefficient of the intrinsic viscosity arises only from the variation of the expansion coefficient, the molecule in the unperturbed state being a normal random coil. The absence of aggregation and draining effects in the above solvents has been varified.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070212
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Polymerization of cyclic imino ethers. VI. X-ray study of some polyaziridines (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 463-473 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Polymers of poly(N-acyl and N-aroyl aziridines) were studied by x-ray diffraction. All the crystalline polymers studied have a triclinic unit cell with two monomer units per unit cell. The a and c (fiber direction) parameters (4.9 and 6.5 A, respectively) are essentially the same for all the cells. The b parameter for the N-acyl polymers, however, increases steadily by a factor of 2 A per methylene group added to the lateral chains. The densities calculated for the unit cells are in agreement with the experimental values obtained. The most probable structure is one in which the molecules assume a planar configuration with the main chain not fully extended. The lateral groups are tilted from the c axis by an angle of 54° in a parallel configuration and alternate on each side of the main chain. This permits these lateral groups to assume packing similar to that of polyethylene. A brief description of the techniques used in this interpretation is included.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Nylon 66 polymers. I. Molecular weight and compositional distributionPresented at the International Symposium on Polymer Characterization, Battelle Memorial Institute, Nov. 29-Dec. 1, 1967. Contribution No. 473 from the Chemstrand Research Center, Inc. (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1-25 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Results from characterization of melt-polymerized nylon 66 by various solution property measurements are reported and employed in analysis of typical molecular weight and compositional distributions for these systems. Critical attention is paid to application of standard procedures including light scattering, viscosity, membrane osmometry and other colligative property measurements in arriving at satisfactory specification of polymer molecular weight averages. Particular consideration is given to polymers extending appreciably beyond the lower and higher limits in molecular weight normally encountered. The conclusions drawn are: (1) in the range of number-average molecular weights less than about 25 000, nylon 66 as ordinarily prepared by melt condensation consists principally of linear species approximating the “most probable” distribution; (2) small amounts of cyclic oligomers are present in all samples: (3) increase in the extent of the melt polycondensation to progressively higher stages is accompanied by secondary reactions and the formation of branched components terminating ultimately in crosslinked, insoluble gels. Intrinsic viscosity-molecular weight relationships in seven solvents, applicable to nylon polymers meeting the requirements of (1) above, are derived.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Influence of defects on the infrared spectra of polymersPresented in part at the Symposium on Spectroscopy of Polymers, American Chemical Society, Chicago, September 1967. (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 57-76 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: For an infinitely repeated regular polymer chain structure the only vibrations which are optically active are those in which the phase of the motion is the same in each unit (the factor-group modes). Frequencies for which the phase difference is nonzero are optically inactive but can become activated by the presence of defects in the chain. Such defects would normally be chemical impurities or conformational irregularities in the chain. A simple theory is developed which shows that for a dilute system of defects the major characteristics determining possible activation of the nonfactor-group modes are: (1) the strength of the coupling between the defect vibration and the vibrations of the neighboring chain, and (2) whether or not the natural frequency of the defect vibration lies inside a lattice band of the regular chain. An analysis of the low- and high-frequency regions of the spectrum of low-density polyethylene, based on the above considerations, indicates that several features of the spectrum can be associated with defect-induced absorption. A similar explanation can account for certain intensity changes in the C—Cl stretching region of syndiotactic poly(vinyl chloroide) when this polymer is submitted to mechanical treatment.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    General description of optical (dichroic) orientation factors for relating optical anisotropy of bulk polymer to orientation of structural unitsThe preceding paper of the same title1 by the same authors, will be designated as Part I of this series.. Part II. Fourth moments of orientation distribution and polarized fluorescence (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 709-724 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A general description is given for relations among the optical quantities obtained from fluorescence polarization measurements on bulk polymer stained by fluorescent groups: the moments of distribution of orientations of the fluorescent groups, and those of the structural units of the polymer (chain segments) on which the groups are adsorbed. Two assumptions as to the biaxial symmetry of the bulk polymer and the cylindrical symmetry of the optical anisotropy of the fluorescent element, both for the absorption and emission processes, reduce the intensities of the polarized fluorescence to a 3 × 3 matrix L which is asymmetric (Lij ≠ Lji), as has frequently been observed in experiments. The components of the L matrix are related to those of the J matrix which is so defined as to describe the fourth moments of the distribution of orientations of the structural units on the basis of a random distribution of the rotational angle of the unit about the segment axis. It is found that the use of the method of fluorescence polarization combined with absorption dichroism and/or emission gives the values of the optical anisotropy ratios of the fluorescent unit, and that the effects of the thermal agitation of the structural unit can be separated from the moments of the orientation distribution for the simplest case.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070409
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    The flow of high polymers. S. Middleman, Interscience, New York, 1968. IX + 246 pp. $12.95 (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 747-748 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070414
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Viscoelastic properties of epoxy-diamine networks (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 753-762 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Eight epoxy-diamine networks have been formed, diamines with 2 to 12 methylene groups being used as curing agents. Dynamic mechanical tests revealed four transition regions in the dynamic loss modulus/temperature relationship. Two possible explanations for the relaxation of the glycidyl portion of the structure are proposed. One of the relaxations could be due to the breakdown of hydrogen bonds through the hydroxyl and ether groups. The second could be ascribed to the relaxation of the unbonded glycidyl groups or a second relaxation of the glycidyl groups after the breakdown of the hydrogen bonds.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070501
    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...