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  • 2010-2014
  • 1965-1969  (851)
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  • 1890-1899  (12)
  • 1967  (851)
  • 1890  (12)
  • Life and Medical Sciences  (434)
  • Physics  (429)
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  • 2010-2014
  • 1965-1969  (851)
  • 1955-1959
  • 1890-1899  (12)
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  • 101
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 179-193 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In order to explain the observed nonvanishing limiting value of dynamic intrinsic viscosity of polymer solutions at ω = ∞ one has considered the necklace model with finite resistance to the rate of coil deformation introduced long ago by Cerf for the study of gradient dependence of intrinsic viscosity and streaming birefringence. The calculation need not take into account change of hydrodynamic interaction as a consequence of coil deformation because the experimental data are always either obtained at very low gradient or extrapolated to zero gradient so that in the experiment the macromolecule has the same conformation as in the solution at rest. The model indeed yields a finite [η]′ω = ∞ in good agreement with experiments on polystyrene in Aroclor. According to the theory [η]′ω = ∞/[η]0 decreases with increasing molecular weight as M-1 and M-1/2 for the free-draining and impermeable coil, respectively. The absolute limiting value [η]∞′, therefore turns out to be nearly independent of M, at least for small values of internal viscosity. From the observed value [η]∞′/[η0] one can obtain the coefficient of internal viscosity of the macromolecule. The value for polystyrene in Aroclor calculated from dynamic experiments on rather concentrated solutions is close to that derived by Cerf from streaming birefringence observations of polystyrene in a series of solvents of widely differing viscosity.
    Additional Material: 5 Ill.
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  • 102
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    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 225-229 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 5 Ill.
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  • 103
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    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 211-223 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The kinetics of radiation polymerization on a solid catalyst is discussed, under the condition that only linear termination of the chain takes place. All the kinetic equations are balance equations of particles of each type adsorbed by unit mass of the catalyst, and this makes it possible to account for the effect on the kinetics of the time dependence of the magnitude of the part of its surface on which the reactions we are considering may take place. Integro-differential equations are used for calculating the molecular weight distribution of the resulting polymer; this ensures higher accuracy of the formulas obtained than when differential equations are used and makes it possible to eliminate a number of limitations generally involved in the transition to differential equations. An expression has been found for the molecular weight distribution of the polymer product which allows for the possibility of radiation-induced catalytic polymerization on the resulting adsorbed polymer. Expressions have been derived for the average molecular weight and yield (weight and molecular) of the polymer formed. Asymptotic formulas have been obtained (for large irradiation times) for all the above values. The conclusions that can be drawn concerning the mechanism of the process based on a comparison of the formulas obtained with kinetic curves plotted from experimental data are given. It is shown how such a comparison can be utilized for calculating the rate constants for polymerization and chain termination reactions.
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  • 104
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    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 195-210 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A phenomenological theory is presented to extend the method of reduced variables for the effects of both temperature and changing degree of crystallinity on the linear viscoelastic properties of solutions of crystalline polymers. The vertical and the horizontal shift factors, which are both obtainable in the course of analysis of the experimental data, are correlated with the concentration of the solution and the volume fraction of the crystalline phase, and the fractional free volume of the system, respectively. Dynamic mechanical properties of a gel of cellulose nitrate (nitrogen content, 12.6%) in diethyl phthalate with a nominal concentration of 18% by weight were obtained in the transition region from glasslike to rubberlike consistency and also in the rubbery plateau region by employing the Fitzgerald apparatus and a freely oscillating torsion pendulum over the temperature range from -49 to 65°C. Application of the new reduction method to the experimental data was found to be quite successful, and it was shown that in general the degree of crystallinity in the system (and hence also the concentration of polymer in the amorphous phase) can depend on both temperature and thermal history. The dynamic mechanical data of a gel of different nominal concentration (23% by weight) previously obtained by Plazek were reanalyzed in terms of the method herein given.
    Additional Material: 11 Ill.
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  • 105
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 230-234 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
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  • 106
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 235-236 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
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  • 107
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 391-393 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 4 Ill.
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  • 108
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 361-375 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The polysaccharide of salep orchid tuber was shown to be a glucomannan with a glucose/mannose ratio of 2.6 and an acetyl content of 2.1%. After extraction from the powdered root with water, the triacetate derivative was prepared and its configurational and hydrodynamic properties examined. The polymer yielded a series of fractions from 615 to 4170 in weight-average degree of polymerization. Light-scattering, viscosity, and osmometry experiments were conducted. Intrinsic viscosity results were interpreted according to the hydrodynamic theory of Eizner and Ptitsyn resulting in a value of ζ/η0 = 20 ± 6 A. for the ratio of monomeric friction coefficient to solvent viscosity and a corresponding value of a = 55 ± 4 A. for the persistence length, closely similar to those reported for other β-1,4-linked polysaccharides. The theoretical Flory coefficient increased with increasing molecular weight but was less than the limiting value of Φ0 = 2.86 × 1023 mole-1. The dependence of the light-scattering radius of gyration of the glucomannan polymer on the contour length showed that the configuration of the heteropolymer was similar to that of other β-1,4-linked polysaccharides which have only glucose or mannose in the main chain. Calculated radii of gyration based on the Porod-Kratky persistence length were found to be smaller than radii found by light scattering on the fractions.
    Additional Material: 7 Ill.
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  • 109
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 583-596 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The optical and mechanical properties of poly(vinyl chloride) film were examined by observing both the stress and birefringence during stretching at constant rate, during relaxation at constant length and during a dynamic birefringence experiment. Experiments were also done by varying the temperature at constant length. The changes in birefringence are interpreted in terms of changes in negative distortional birefringence, changes in positive orientation birefringence, and possible reversible changes in birefringence with temperature arising from conformational changes in the polymer chain and changes in the contribution of birefringent crystals.
    Additional Material: 10 Ill.
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  • 110
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 597-613 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The dependence of crystalline morphology of isotactic polypropylene crystallized from dilute solutions on its molecular weight and growing conditions and the mechanism of crystal growth were studied by electron microscopy and electron diffraction. Lathshaped lamellar crystals 150-300 A. in thickness are obtained from fractionated polypropylene powders of Mw (average molecular weight) = 600,000 and 240,000, but not from the samples of Mw = 82,000 and 44,000, by means of isothermal crystallization at 130°C. for 20 hr. in dilute α-chloronaphthalene solution (0.005 wt.-%). Precipitation of the fractionated polypropylene sample of Mw = 82,000 from a dilute solution of carbitol gives typical dendritic crystals under the same isothermal crystallizing conditions as mentioned above. The mode of chain folding in these crystals based on the orientation and the crystal structure of the lamellar crystals agrees with that proposed by Sauer, Morrow, and Richardson. From the morphological observations, the mechanism of growth pertinent to polypropylene lamellar crystals is presumed to be as follows: fibrils at first aggregate, then the molecular chains are folded to form small lamellae, and then these small lamellae accumulate compactly to grow to large, lath-shaped, lamellar crystals.
    Additional Material: 12 Ill.
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  • 111
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 697-704 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Measurements of the spin-lattice relaxation times (T1) of solvent protons have been performed on systems containing mixed solvents with and without polymer. It has been found that the motion of solvent is selectively affected by polymers present in the system. Polyisobutylene (10%) in mixed solvents of carbon tetrachloride (or cyclohexane) and dichloromethane at various proportions produces little effect on T1 values of dichloromethane, but it affects significantly the T1 values of cyclohexane; whereas poly(methyl methacrylate) (10%) in carbon tetrachloride and dichloromethane (or acetone) selectively associates with dichloromethane (or acetone), resulting in an approximate 50% reduction of the T1 values for dichloromethane (or acetone). In systems of poly(methyl methacrylate) and three mixed solvents of carbon tetrachloride, dichloromethane, and cyclohexane, the polymer (10%) has a negligible effect on the T1 values of cyclohexane, but brings about a 50% reduction of the T1 values of dichloromethane. These phenomena are discussed in terms of local selective interactions between the solvent molecules and the polymeric chain segments.
    Additional Material: 1 Ill.
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  • 112
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 705-710 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Recent precision measurements of the heats of combustion of atactic and isotactic polystyrene permit an unequivocal calculation of the enthalpy difference in the bulk amorphous forms of the two isomers of this polymer. Contributions to this quantity arise mainly from the differences in nonbonded interactions in the two configurations but may also contain terms relating to higher energy conformations and to intermolecular interactions. The thermochemical and NMR data of specific polymers and of simple molecules are discussed in a comparison with model compound calculations. The thermochemical method has potentially important applications in studying molecular interactions in stereoregular polymers.
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  • 113
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The Tian-Calvet microcalorimeter has been used to measure the heat of solution of atactic polystyrene in toluene at 30°C. By using a special technique for polymer sample preparation, it has been possible to measure directly the difference in conformational energy of the polystyrene chain at different temperatures, from 30 to 100°C. and to calculate its contribution to the specific heat.
    Additional Material: 1 Ill.
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  • 114
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 711-742 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A general method is presented for taking into account changes in volume in several types of calculations concerned with spherulite deformation in semicrystalline polymers. The method is applicable at large strains for which the low-strain limiting form of the equation defining Poisson's ratio is no longer valid. Applications are made to calculations of the three crystal orientation functions for models of spherulite deformation based on those proposed by Wilchinsky, Stein et al., and Oda et al. The effects of changes in volume are considered in detail and are compared with previous results in which the volume change was neglected. Calculations of spherulite birefringence are considered in a similar manner, as are the equations for determining spherulite deformation by means of low-angle light-scattering measurements. Results indicate that in several cases details of deformation mechanisms previously proposed should be revised in light of the effect of the change in volume on the calculated orientation functions. The equations in each case are presented in terms of a parameter β, the square root of the third strain invariant of the deformation tensor. Results are presented in numerical form for many of the basic parameters. Equations for all such results are expressed in explicit form and, in most cases, are displayed graphically together with available experimental data.
    Additional Material: 9 Ill.
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  • 115
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 761-769 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The α, β, and γ transitions at temperatures between -200 and +100°C. of crosslinked aromatic and aliphatic epoxy polymers were determined from damping and shear modulus data, and compared with their fluorine containing analogs. Loci of segmental relaxation are suggested at various temperatures, and similarities between aliphatic and fluorocarbon segments, and polyethylene and polytetrafluoroethylene are discussed. Two systems of structurally similar monomers 2,2,3,3,4,4-hexafluoropentane diglycidyl ether-1,5 and 1,4-butane diglycidyl ether, and 2,2-bis(4-glycidyl phenyl ether)hexafluoropropane and 2,2-bis(4-glycidyl phenyl ether) propane were polymerized with the aid of two diamine curing agents, namely, ethylenediamine and m-xylylenediamine. Polymers of the aromatic diepoxides showed transitions with peaks at -56°C. and above +70°C. Three main peaks were registered for the aliphatic and fluorocarbon diepoxides: at -125 and at -100°C., at -56°C., and at 0°C. It is suggested that the Tg is affected by an interdependence of relaxation of all components of the polymer main chain.
    Additional Material: 10 Ill.
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  • 116
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 781-790 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A description is given of a modified cone-and-plate apparatus suitable for the measurement of the streaming birefringence of molten polymers. Some results are given of measurements on a polystyrene and a poly(dimethyl siloxane). Those on polystyrene are compared with solution measurements of the same material by use of the well-known Bueche-Harding parameter. Measurements on the silicone oil have been compared with measurements of the dynamic moduli on the same material, after ascertaining the validity of the stress-optical law for this system as well.
    Additional Material: 5 Ill.
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  • 117
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 791-794 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
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  • 118
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 795-798 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
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  • 119
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 799-816 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The concentration of solvent in the gel phase of a swelling polystyrene-divinylbenzene copolymer bead has been measured as a function of the radius by optical interference techniques. It is found that an appreciable gradient exists even shortly after the core disappears. Results are presented for two cases: a very lightly crosslinked bead that exhibits negligible birefringence while swelling, and a more tightly crosslinked network in which the birefringence must be considered. It is also found that the refractive index of the unswollen bead is considerably less than that found by extrapolation from the swollen state; this effect is reasonable when the “free volume” in the bulk polymer is considered.
    Additional Material: 15 Ill.
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  • 120
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 817-828 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The dispersion of birefringence in oriented amorphous polymers is discussed. It is shown that for polystyrene, the birefringence can be considered as the product of an orientation function and a function of the wavelength of the light. This leads to a method for expressing the birefringence dispersion as a function that is characteristic of the polymer. This function is determined for polystyrene, and from it the birefringence at infinite wavelength is found to be 11% lower than that measured with the mercury green line (5461 A.).
    Additional Material: 8 Ill.
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  • 121
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 829-838 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The molecular dimensions of polydipropylsiloxamer were studied by intrinsic viscosity measurements in toluene and in 2-pentanone. The relationships between the molecualr weight and the intrinsic viscosity were found to be: [η]25°C., toluene = 4.35 × 10-4 M0.58; [η]θ(10°C.), toluene = 1.09 × 10-3 M0.5; [η]θ(76°C.), 2-pentanone = 8.71 × 10-4 M0.5. This held reasonably well for molecular weights from 25,000 to 3000,000. The root-mean-square end-to-end length ratio, (r02/M)1/2 as calculated from the constant K, exceeds the free rotation value by approximately 100%. The disparity is greater than that found with polydimethylsiloxamer, indicating a lower degree of flexibility for the polydipropylsiloxamer. This is largely due to the short range steric interaction between near neighboring units of the chain. Gel permeation chromatography was also employed to demonstrate the lower degree of flexibility for polydipropylsiloxamer as compared with polydimethylsiloxamer.
    Additional Material: 5 Ill.
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  • 122
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 853-874 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In earlier work we have indicated a superposition principle for moderately concentrated mixtures (c ≲ 2/[η]) in good and poor solvents. By an examination of data on a number of vinyl polymers and cellulose derivatives in good as well as poor solvents, the validity of this principle is extended to concentrated solutions (c ≲ 50%). The characteristic concentration factor γ is proportional to M-a1 over the whole concentration range, with 0.47 ≤ a1 ≤ 1.10 being larger for good than for poor solvents, the result obtained earlier. Significant deviations from this relationship are noted in good solvents for those low molecular weights at which deviations from the usual intrinsic viscosity relationship occur. This may be related to the expansion factor of the polymer coil. On the basis of these results, the concentration and molecular weight dependence of the viscosity in the concentrated solution can be related to each other in terms of the parameter a1 and thus to thermodynamic characteristics. In this manner a bridge between the relatively dilute and concentrated regions is established. Currently used semiempirical expressions are analyzed in terms of these results. For the polystyrene-cyclohexane systems and θ - 9 ≦ T ≦ θ + 3, γ can be identified with the critical concentration for phase separation. Provided an “entanglement” concentration ce exists, in the neighbourhood of which the concentration dependence of the viscosity changes reapidly, γ can alternatively be shown to be proportional to ce, or ce ∝ M-a1. The temperature reduction scheme suggested earlier remains to be investigated.
    Additional Material: 10 Ill.
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  • 123
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Molecular weight M and concentration c dependencies of the zero-shear viscosity (η) were measured over wide ranges of M and c for concentrated solutions of linear and branched poly(vinyl acetate) as well as of polystyrene under θ conditions. The log η versus log M and log η versus log c curves for a given system can be superposed by the horizontal shift along the abscissa, giving smooth master curves. From the shift factors the ratio of two exponents β and α, which appear in the following equation, can be evaluated: η = K′(cρ)αMβ, where ρ is the density of the solution and K′ is a constant at constant temperature. The evaluated values of β/α for the systems under θ conditions are equal to or very close to 0.50 as was anticipated from the previous work. The above superposition method was also applied to available viscosity data, and it was found that β/α had a good correlation with a in [η] = KMa. This indicates that the individual molecules in concentrated solutions maintain the same individuality as in dilute solutions, and might be a positive support to the packed sphere model proposed previously by the authors. The effect of solvent on the molecular weight and the concentration dependencies of viscosity was also discussed.
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  • 124
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 915-927 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The homopolymer and many of the copolymers of N-acrylylglycinamide yield thermally reversible gels in water. These systems are uniquely suitable for studying synthetic photographic gelatin substitutes and for understanding the mechanism of the gelation process. Polymerization of N-acrylylglycinamide has been studied under a variety of conditions. The homopolymer is aggregated in dilute aqueous solution and probably molecularly dispersed in 2M thiocyanate solution. At concentrations of several per cent, in water, thermally reversible gels are formed whose melting points rise with increasing concentration and increasing molecular weight. The heat of gelation crosslinking has been calculated to be -8.8 kcal./mole of crosslinks. Introduction of small amounts of carboxyl groups into the polymer raises the melting points of the aqueous gels. The effect of various organic and inorganic reagents on gelation is presented. The ability to prepare copolymers which can be flocculated has been demonstrated as well as the usefulness of the monomer in certain types of photoresist systems. Copolymerization with acrylic acid and β-aminoethyl vinyl ether has been studied, and the r1 and r2 values for these systems have been calculated as well as Q and e values for N-acrylylglycinamide.
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  • 125
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 929-938 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Free radicals produced in irradiated polypropylene were studied by the electron spin resonance method. Two temperature regions in which the free radicals decay rapidly were found at around 170°K. and 260°K. The first temperature region corresponds to the γ-dispersion of polypropylene and the second to the β-dispersion. Steric configurations of the free radicals were investigated, and it was concluded that the free radicals trapped in polymer, conformation of which is appreciably twisted from the stable 31-helical structure, decay with small-scale motion of the matrix polymer. The decay of free radicals trapped in polymer of less twisted conformation is associated with the large-scale motion of the matrix polymer. Activation energies of decay were found to be 11 kcal./mole at the lower temperature and 48 kcal./mole at the higher temperature. Time constants of the decay reactions were compared with those for molecular motion of the matrix, with results reflecting the relations of the decay of the polymer radicals to molecular motion in the matrix.
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  • 126
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 939-955 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The deformation of fresh and aged polybutene-1 spherulitic samples has been investigated by microscopic observation, interferometry, studying macroscopic and spherulitic birefringence changes, and study of light-scattering patterns. The spherulite deformation is not affine, the microscopic deformation ratio being less than the macroscopic deformation ratio of the sample and greater in the equatorial regions of the spherulite than in the polar regions. The deviation from affine deformation is less for fresh spherulites than for the aged, where void formation occurs in the equatorial part of the spherulite. This gives rise to large scattering by this part of the spherulite and to form birefringence. The spherulite birefringence and its change with elongation is dependent upon the degree of aging of the sample. The spherulite birefringence is more negative for the aged sample. In the polar regions of the spherulite, this negative birefringence decreases and turns positive at higher elongations, characteristic of a reorientation of the crystals with their optic axes turning from being perpendicular to parallel to the spherulite radius. The spherulite birefringence in the equatorial direction becomes somewhat more negative on stretching a fresh sample but less negative on stretching an aged one. Spherulite distortion and orientation changes are apparent from the light-scattering patterns of films possessing small spherulites. The changes in Vv and Hv scattering patterns upon stretch are different for the fresh and aged samples. The Vv patterns of the fresh samples decrease in intensity with time after stretching a fresh sample with the Hv patterns do not.
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  • 127
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 987-988 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
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  • 128
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 989-989 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
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  • 129
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1013-1028 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The influence of the species of counterion on the polyelectrolyte behavior and the conformation of poly-L-methionine S-methylsulfonium salts in aqueous solution was studied by viscometric, electrochemical, and optical measurements. The degree of binding of small counterions to charged polyions increases in the sequence: chloride ≲ bromide 〈 iodide 〈 thiocyanate. The conformations of chloride and bromide salts are independent of polymer concentration. On the contrary, iodide and thiocyanate salts indicate a conformational transition, probably from a random-coil conformation to an intermolecularly stabilized β-form, with the increase of polymer concentration. The results suggest the existence of a strong specific interaction between counterion and macroion in iodide and thiocyanate salt solutions at high polymer concentration.
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  • 130
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 991-1012 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Single-crystal preparations of polyethylene were treated with the selective oxidizing agent, fuming nitric acid. The degraded products were examined as regards layer thickness (by low-angle x-ray studies), chemical and weight changes, recrystallization and annealing treatments, and by broadline NMR, as part of a systematic investigation aimed at clarifying the nature of disordered material in single crystals. It emerges that there is a disordered-mobile region along the fold surface of the crystals in agreement with other parallel works along similar lines. In a more detailed analysis we can now decompose the nitric acid attack into components affecting the basal and side surfaces, respectively. Taking into account the recrystallization-annealing observations, we infer that the fold surface is heterogeneous with folds of more than one kind. These results were combined with a preliminary molecular weight distribution study by gel permeation chromatography. Taking into account all the available evidence, we are led to suggest a composite structure where surface looseness, coresponding to long loops and hairs, is superimposed on the more regular folded surface. This model is in the process of being tested. The problems concerning the assignment of a value to the amount of surface looseness are being discussed. In addition, a discontinuity in the thermal behavior of the crystals between 75 and 80°C. has been detected.
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  • 131
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1029-1042 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: This paper is devoted to the determination of the number of intermolecular bonds in a polymer crosslinked according to the following process: (1) crosslinking in the usual isotropic state, (2) additional crosslinking of the strained primary network. The Flory equation for swelling in solvents has been modified in order to take into account the oriented state of the initial network at the time of secondary crosslinking. The combination of this equation with those relating the modulus of elasticity and the dimensions of the relaxed sample to the deformation of the primary network at the time of secondary crosslinking leads to different possible evaluations of the number of intermolecular bonds. Their significance is discussed. The equations thus established are tested with natural rubber samples vulcanized according to the above-mentioned process. The validity of the number of crosslinks thus calculated is discussed; a partial degradation of the primary network occurs during the second crosslinking. Its influence is taken into account by using the approximated equations proposed by Flory. The efficiency of the vulcanizing agent (TMTD) is consequently shown to be practically independent of the deformation of the primary network at the time of secondary crosslinking.
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  • 132
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1087-1101 
    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 long-chain branching on the size of low-density polyethylene molecules in solution is demonstrated through solution viscosity and molecular weight measurements on fractionated samples. These well-characterized fractions are analyzed by gel permeation chromatography (GPC), and it is shown that the separation of the polymer molecules by this technique is sensitive to the presence of long-chain branching. By using fractions of branched polyethylene possessing differing degrees of branching, one observes that a single curve is adequate in relating elution volume to molecular weight. This calibration curve is applied in the GPC analysis of a variety of commercial low-density polyethylene resins and it is shown, by comparison with independent osmometric and gradient elution chromatographic data, that realistic values for molecular weight and molecular weight distribution are obtained. The replacement of molecular weight M by the parameter [η]M as a function of elution volume, leads to a single relationship for both linear and branched polyethylenes. This indicates that GPC separation takes place according to the hydrodynamic volumes of the polymer molecules. The comparison of data for polyethylene and polystyrene fractions suggests that this volume dependence of the separation will be observed for other polymer-solvent systems.
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  • 133
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    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The standard methods of measuring the elastic properties of polymer melts are briefly reviewed and a method of measuring another combination of viscoelastic properties, the melt strength, is described. Data are presented on the melt strength of various types of polyethylene resins and on ionomer resins. The effects on various viscoelastic properties of branching or of the addition of fine fibrils of Teflon perfluorocarbon resin are reported.
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  • 134
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1293-1295 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
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  • 135
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1283-1292 
    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 microstructure on crystallizability of polyoctenamers prepared by R3Al-WCl6 catalyst was studied. The results indicate that polyoctenamers with a broad range of trans-vinylene content do crystallize. The measured melting points are dependent on the trans-vinylene content. From the dependence of melting temperature on copolymer composition, a value of 73 ± 2°C. for the melting point and a molar heat of fusion ΔHu of 3520 cal./mole are calculated for 100% trans-polyoctenamer. From the melting point depression in the presence of diluent, a value for ΔHu of 4800 cal./mole is obtained.
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  • 136
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Current theories of polymer flow processes often sacrifice realistic molecular models for simplicity of their mathematical equations. An analysis of what might happen to molecules of more realistic sizes and shapes under shear flow, shows the importance of the rapid Brownian motion of chain segments, the elastic deformations of polymer random coils, and the dissipation of this elastic random coil energy by the relatively slow slippage of the chains past each other at a few entanglements where steric hindrance causes long relaxation times. This makes the energy loss depend on the time at each local deformation, and not on the overall shear rate. At high shear rates this model leads to “cluster flow” and low loss cyclic deformations, rather than the high loss processes of steady-state shear. This model gives reasonable qualitative explanations for many anomalous flow properties, and it has predicted new effects that have since been observed.
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  • 137
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1305-1308 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 7 Ill.
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  • 138
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1309-1312 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
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  • 139
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1157-1175 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Equations are developed for predicting the distributions of degree of substitution and block length in substitution copolymers which result when homopolymers are subjected to substitution reactions. Several different cases are treated differing in complexity from entirely random substitution to substitution affected by substituents already present on the same and on the neighboring repeat units. The equations are then applied to chlorinated polyethylene as an example of their use.
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  • 140
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1177-1187 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The mechanism of carbon black reinforcement was studied by examining stress-strain properties of preswollen (i.e., cured in the swollen state then deswollen) SBR-1500 vulcanizates and the effect of heat treatment on such samples. It was found that the supercoiling of molecular chains leads to a purely viscous response at low elongations. On heating of preswollen samples, molecular rearrangement at the carbon black surface occurs, leading to a considerable increase in modulus. The activation energy of that process was determined by using the superposition principle.
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  • 141
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    Keywords: Physics ; Polymer and Materials Science
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    Topics: Chemistry and Pharmacology , Physics
    Notes: The theory of the equilibrium distribution of a mixture of different size species of a polymer between two liquid phases is reviewed and used as a basis for the calculation of the dependence of fractionation efficiency on overall concentration, interaction coefficient (hence, choice of solvent and temperature), average molecular weight, and the spread of the molecular weight distribution in the polymer. The special case of a single type of polymer in a single solvent, for which the polymer-solvent interaction coefficient is independent of concentration, is dealt with quantitatively. The ultimate aim is to make it possible to determine systematically the optimum solvent (or mixture of solvents), temperature, and overall concentration for fractionation of a given type of polymer, having a given average molecular weight and molecular weight distribution, considering practical limitations, e. g., the total volume which can conveniently be handled and the time required to achieve a sufficiently close approach to equilibrium.
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  • 142
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1296-1299 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 4 Ill.
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  • 143
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    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1300-1304 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
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  • 144
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    The @Anatomical Record 157 (1967), S. 559-575 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The fine structure of the straight portions of the ductuli efferentes of the opossum were studied by light and electron microscopy. Two cell types, a ciliated and non-ciliated cell, characterize the simple columnar epithelium that lines the ductuli. The non-ciliated cell possesses an extraneous coating of the luminal plasma-lemma, aggregations of apical canaliculi, and vacuoles of varying density distributed in the supranuclear cytoplasm. Such morphological criteria have been regarded as suggestive evidence for absorptive function. The epithelium rests upon a thick basement membrane beneath which are variable amounts of smooth muscle and connective tissue elements.Observations of the structure of the simple squamous epithelium lining the processus vaginalis are reported.Myelinated and unmyelinated nerves are found in the adnexa of the ductuli. These are enclosed in a thin, cellular investment, the innermost layer of which is usually incomplete. This cellular wrapper is considered a “perineural epithelium” but its characteristics are at variance with those found in the recent literature.
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  • 145
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    The @Anatomical Record 157 (1967), S. 589-605 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Although the extravascular origin of erythrocytes from undifferentiated mesenchymal or reticular cells in mammalian bone marrow is generally accepted, the morphological evidence on which this concept is based has not conclusively ruled out the possibility of endothelial cell contributions to erythropoeisis or of the preferential localization of developing erythrocytes within endothelial cell-lined spaces. Since conventional methods of tissue preparation have produced artifacts which obscure the fine details of marrow architecture, the re-examination of this problem using newer histological and fixation methods permits a more critical study of the bone marrow in nearly artifact free sections.Ribs and long bones of 65 rabbits, ranging from 18 days of gestation to the second day after birth were removed, fixed intact with 10% aqueous acrolein, decalcified in 5% aqueous nitric acid and embedded in plexiglass-methacrylate. Two micron sections stained with toluidine blue were examined with the light microscope. Serial paraffin sections of formal-Zenker fixed material also were examined.Morphological studies conclusively indicate that erythrocytes develop extravascularly arising from mesenchymal or reticular cells in the fetal bone marrow. Mature erythrocytes enter the circulation through discontinuities in the sinusoidal walls. Neither endothelial cells or blood-borne lymphocytes make an apparent contribution to erythropoiesis. The first hemopoietic cells to form in the fetal marrow are determined and develop along the erythrocytic line. These proerythroblasts initially arise randomly in the marrow parenchyma and are not in obvious association with the sinusoids. Subsequent maturation and proliferation of the primitive erythrocytic cells result in the formation of colonies of erythrocytic cells at all stages of development. As these colonies enlarge, the erythrocytic elements come in close association with the sinusoids. In later stages of marrow development, developing erythrocytic and granulocytic cells become intermixed and more randomly associated in the extravascular space of the marrow.
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  • 146
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A description is given of the fine structure of perilymphatic fibrocytes and their associated fibers in the vestibule of the inner ear in rats. The identification of the extracellular fibers as keratin is discussed in relationship to their fine structure and to biochemical and biophysical data of other workers. The numerous junctional complexes between fibrocytes are described and it is shown that these do not form zonula occludens as has been reported by other workers.
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  • 147
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Carotid bodies from 11 cats were prepared for study with the electron microscope. All cats used were initially healthy and weighed from 1.5 to 4.0 Kg. Four cats were given daily doses of reserpine 1.5 mg/Kg for 2, 3, 4 or 12 days; the other cats were untreated. Carotid bodies were fixed by immersion in Dalton's fluid, collidine buffered osmic acid or 3% potassium permanganate in 0.1 M phosphate buffer. Other carotid bodies were fixed by perfusion with buffered formalin or with 3% glutaraldehyde in phosphate buffer. Each fixative produced distinct differences in the appearance of the carotid body, particularly in the size and opacity of the granules within the characteristic vesicles of glomus cells (type I). After Dalton's fixative the granules were faint and inconspicuous whereas after osmic acid fixation the granules were very dense but small in comparison to the size of the enclosing vesicular membrane. Aldehyde fixation resulted in very dense granules that almost completely filled the vesicles but permanganate fixation produced vesicles that were devoid of the dense central cores except for a very few. Carotid bodies from reserpine treated cats that were fixed in osmic acid displayed empty vesicles while those from reserpinized animals fixed by perfusion with glutaraldehyde revealed granules that differed little from normal in numbers, size and density. However, vesicles in the adrenal medulla and in sympathetic nerve endings in the pineal gland from the same animals contained empty vesicles. The results are regarded as evidence of a different degree or method of binding between catecholamines and other components of the vesicles in glomus cells when compared to similar vesicles in sympathetic nerve endings and the adrenal medulla.
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  • 148
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    The @Anatomical Record 157 (1967), S. 701-703 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 149
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    The @Anatomical Record 158 (1967), S. 35-42 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Bloodstream flow patterns have been outlined in the arterial outflow tract (ventricular outflow tract and bulbus arteriosus) of the chick embryo heart during the period in which septation takes place, Hemodynamic factors underlying flow changes during this period are discussed.The mapping of flow patterns did not support the concept of a conoventricular flange reported previously. Septation was found to take place between two separate and discrete bloodstreams.The cellular nature of the aorticopulmonary septum has been described. The spiral ridges that form this septum expand by cellular growth, explaining the ability of this septum to develop against the direction of blood flow. The aorticopulmonary septum divides about two-thirds of the arterial outflow tract; the final partitioning of the most proximal portion of the outflow tract was found to take place by means of the apposition of endocardial cushion tissue masses.Failure of aorticopulmonary septum development (truncus arteriosus communis persistens) was found to follow fusion of the bloodstreams in experimental studies. In experimental aortic stenosis the appearance of a small left stream was found to be followed by the development of a stenotic aorta. Thus in the first instance the septum apparently cannot develop unless the streams remain separate and in the second case the size of the prhnordial bloodstreams appears to determine the diameter of the vessel.
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  • 150
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Chick embryos were inoculated with influenza-A virus over the blastoderm at 42-50 hours incubation (37°C). Surviving embryos were harvested 24 hours later, Grossly and microscopically, the developing brain exhibits a type of abnormality in which the neural wall is highly convoluted with folds projecting into the ventricular cavities, suggesting “overgrowth” of the neural tissue.A comparison of measurements on projection drawings of serial sections of virus inoculated and control embryos at comparable developmental stages indicates that the ventricular surface area, volume of brain tissue and volume of the ventricular cavity are markedly less in the experimental embryos, but average thickness of the brain wall is greater. There are fewer nuclei and mitotic figures in experimental embryos, although average nuclear and mitotic densities and mitotic index are approximately the same as control values.It is evident that the characteristic neural defect is not due to excessive growth, since the volume of brain tissue and number of cells are consistently less in experimental embryos. It is concluded that the virus infection results in an inhibition of growth of the brain wall, and that the increased thickness and foldings must result from collapse of the brain which in turn may be due to a decrease in the amount of ventricular fluid.
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  • 151
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    The @Anatomical Record 157 (1967), S. 657-665 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: With all other environmental factors rigidly standardized, normal Sprague-Dawley rats were maintained under the following schedules: (1) 12 hours of artificial light 0600 to 1800 alternating with 12 hours of darkness-LD; (2) reversal of the first-DL; (3) constant darkness-DD, and (4) constant illumination-LL.After the animals had been under a specific lighting regimen for at least three weeks, blood coagulation times were determined on separate groups of 8 to 16 animals at bi-hourly intervals during a 24-hour period. Significant daily fluctuations or rhythms in coagulation times under all lighting conditions were found by plotting each of the bi-hourly mean values as a function of time. The temporal phasing of all rhythms in LD, DL, LL and DD were similar. The major changes found in the different lighting schedules involved overall magnitude, e.g., the overall 24-hour mean coagulation time for rats maintained in LL was 21% greater than for rats maintained in DD. Although total adrenalectomy or adrenal medullectomy did not abolish the characteristic LD rhythm, there was about a 100% decrease in the mean 24-hour coagulation time of LD adrenalectomized animals when compared to normal LD animals. No significant decrease was seen in adrenal demedullectomized animals when similarly compared with normal LD animals.
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  • 152
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    The @Anatomical Record 157 (1967), S. 699-700 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The recurrent branch of the anterior cerebral artery is of considerable applied importance. The extracerebral course of the vessel has been studied in dissection of 12 brains. Numerous variations in the course of the vessel were found and these have been presented.
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  • 153
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    The @Anatomical Record 157 (1967), S. 701-701 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 154
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    The @Anatomical Record 158 (1967), S. 11-19 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The right atrioventricular junction and A-V node area in each of five human hearts was studied histologically in serial sections. The A-V node of a 54-year old female was reconstructed in four colors to provide a three-dimensional model of cardiac relationships, blood supply, and nodal configuration. The nodal fibers demonstrated two laminations. A superficial layer was composed of longitudinally oriented fibers, whereas a deeper layer was composed of oblique and transversely directed fibers. The atrioventricular bundle fibers were always continuous with nodal fibers of the deeper portion of the A-V node. Atrionodal fiber junctions occur along the superior, endocardial and inferior borders of the A-V node and impart to these surfaces a spiked appearance. The potential significance of A-V node structure to atrial cardiac conduction is presented.
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  • 155
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    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The innervation of the aortic arch and associated arterial trunks was investigated in the pig by gross dissection, by microscopic examination of normal arterial walls, and by observation of degenerative changes following selective surgical interruption of right and left cervical vagi. It is concluded that the aortic depressor fibers of the pig are organized unilaterally, being distributed by the left vagus to arterial walls, and by observation of degenerative changes following selective surgical with the absence of a dissectable right aortic nerve, there was no histological evidence of sensory innervation in the walls of the brachiocephalic, right subclavian, bicarotid or right common carotid artery. The majority of depressor endings were located in the ventral wall of the aortic arch in a band extending between the origin of the left subclavian artery and the aortic attachment of the ligamentum arteriosum. A few were present in the dorsal wall of the aortic arch and the ventral walls of the pulmonary trunk and ligamentum arteriosum. The depressor fibers were thick, heavily myelinated, varicose, extensively branched and associated with numerous terminal and intercalated neurofibrillar corpuscles. The only epithelioid body observed was a poorly innervated, rudimentary paraganglion in the interval between the aortic arch, the pulmonary artery and the ligamentum arteriosum.
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  • 156
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    The @Anatomical Record 158 (1967) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 157
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    The @Anatomical Record 158 (1967), S. 111-113 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An investigation into the source of the cells present in the endometrial arteries of the pregnant Macaque is presented. By comparing the levels of sex chromatin found in these cells with those in fetal cytotrophoblast and in maternal endometrial stroma it was possible to determine that they are essentially of fetal origin.
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  • 158
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    The @Anatomical Record 158 (1967), S. 99-109 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An attempt to survey spontaneous teratogeny among nonhuman primates bred under laboratory conditions revealed interesting but nonconclusive results. Data on controlled breeding in 2950 animals representing 12 species yielded an estimated incidence of 0.44% malformations. No indication was found that other primates display more malformations than man, and the limited information available suggests that there may be fewer spontaneous defects in nonhuman forms.Macaques and baboons appear to respond in a similar manner and to the same types of extrinsic agents as does man. Thalidomide, Rubella virus and androgenic hormones produce similar defects in comparable dosage at equivalent stages in development in both groups. Several other agents thought not to be teratogenic in man have been realistically tested in primates and also found to be non-teratogenic.Using thalidomide an attempt was made to determine the degree of sensitivity and delimit the susceptible period of Macaca mulatta to this drug. Typical limb malformations were obtained with a single dose of as little as 16 mg/kg between the twenty-fifth and thirtieth days of gestation. Comparable doses at earlier and later ages were without effect, thus defining the susceptible period. In addition, evidence of a positive dose-response relation and of a cephalocaudal gradient in teratogenesis was obtained.
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  • 159
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A total of 286 blastocysts were recovered 6 to 8 days post coitum (p.c.) from untreated or ovariectomized rabbits. The weight of the blastocyst and the volume of the blastocoelic fluid increased at a linear rate from seven to seven and one-half days p.c., thereafter they increased more rapidly. The weight of the embryonic tissue did not change appreciably between seven and eight days p.c. The appearance of protein in the fluid was dependent on the stage of development, albumin being first detectable at six days p.c. Seven days p.c., β-globulin was detectable, followed by α- and γ-globulins (seven and one-quarter days p.c.) and fibrinogen (seven and one-half days p.c.). Seven and one-half days p.c., the electrophoretic distribution of proteins was qualitatively similar to that of the maternal serum and peritoneal fluid, however, quantitatively different. Ovariectomy at six days p.c. had no effect 24 hours later on blastocyst growth or blastocoelic fluid volume. In contrast, ovariectomy at six and one-half days p.c. had a negative effect 24 hours later on blastocyst growth, blastocoelic fluid enhancement and albumin accumulation in the fluid. These latter three phenomena were alleviated by administration of progesterone.
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  • 160
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    The @Anatomical Record 158 (1967), S. 177-189 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Extraocular muscles of the rat possess numerous nerves suitable for the study of fine structure. In these muscles, small nerves made up of one to ten myelinated and unmyelinated nerve fibers are surrounded by two or three layers of perineurium. The perineurium is arranged in concentric sleeves, each one cell thick. Continuous boundary membranes separate the perineural sleeves from the epineural and endoneural tissue space, but the boundary membranes may be spotty or absent between individual sleeves. The presence of boundary membranes around perineural cells distinguishes them from nearby fibroblasts which lack similar membranous investment. Tight intercellular junctions join the cells comprising each sleeve so that the nerves are completely ensheathed in perineurium. The number of sleeves decreases as the nerve becomes smaller, either by the termination of the innermost sleeve or by the loss of a sleeve as the nerve branches. The last sleeve ends shortly before the termination of the nerve. The perineurium is thus open-ended peripherally and, at these places, the epineurium and endoneurium are continuous. Continuities between the epineurium and endoneurium also exist at the entrance and exit of blood vessels supplying the nerve and at points where reticular fibers pierce the perineurium. These structural features correlate well with the action of the perineurium as a diffusion barrier and as a pathway in the transmission of infections.
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  • 161
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Attention is directed to an unusual type of junctional complex between Sertoli cells in the seminiferous epithelium. The space between the membranes of adjoining cells is narrowed to 70-90 Å over large areas of their contact surfaces. In the superficial cytoplasm of each cell is an extensive cisterna of the endoplasmic reticulum, parallel to the membrane and 400-600 Å from it. Spaced at more or less regular intervals in the thin layer of cytoplasm between the cisterna and the cell membrane are periodic densities that appear to be band-like aggregations of fine filaments. The sub-surface cisternae are smooth-contoured on the side toward the cell membrane but bear ribosomes on the side facing the cytoplasm. The possible significance of these distinctive junctions is discussed in relation to the support of the germ cells and the coordination of the developmental events in the cycle of the seminiferous epithelium.
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  • 162
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A method for applicating liquid material into the circulation of rats via the heart is described and the applicability is exemplified in some illustrations.
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  • 163
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    The @Anatomical Record 158 (1967) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 164
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The contents of the facial canal (first and second parts of the facial nerve, and geniculate ganglion), the tympanic plexus, the greater and lesser petrosal nerves, and all intervening connections were dissected in 40 cadavers. This entire nerve complex was removed in 30 cases, and in parts in ten cases, dehydrated, and stained with Sudan Black B or Protargol. A constant communication from the second part of the facial nerve, the geniculate ganglion, or the greater petrosal nerve was observed to pass to the lesser petrosal nerve in all dissections. A review of the literature indicates other points relative to the exchange of autonomic fibers between the facial and glossopharyngeal nerves.
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  • 165
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Skin specimens were obtained from every representative region of the body of an adult Finback whale (Balaenoptera physalus) and examined by means of various histochemical and histological techniques. The following characteristic features were found:The epidermis is exceedingly thick over the general body surfaces and varies from a maximum of 3.0 mm over the ventral surface to 2.5 mm on the back.The complex understructure of the epidermis has rete ridges oriented to the craniocaudad body axis.The papillary layer of the dermis has long and pointed papillae which are wedged into the epidermis.The sensory cutaneous nerve endings demonstrated by silver impregnation and cholinesterase consist predominantly of small Vater-Pacini corpuscles situated in the higher level of the dermis.The intricate blood capillary network, positive for alkaline phosphatase is encased in the dermal papillae.There are no hair follicles, sebaceous and sweat glands.
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  • 166
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The chemotactic behavior of the cells of bone marrow, lymph node, and buffy coat has been studied in tissue culture. Heat-attenuated S. aureus was found to be a consistent and convenient chemotactic agent. Mature granulocytes showed chemotaxis to this agent, whereas bone marrow stem cells did not show chemotaxis. In this respect they behaved like lymphocytes of peripheral blood or of lymphatic tissue, which also do not exhibit chemotactic behavior. The chemotactic, locomotory and morphologic similarities between the lymphocyte and the stem cell of the bone marrow are discussed in relation to the developmental potencies of these cells. Chemotactic behavior of the granulocytes appears to develop between the myelocyte and the metamyelocyte stages. It is possible that the granulocytes have differences in chemotactic ability in vivo also, which could be a factor in the selective migration of the mature granulocytes from their extravascular sites of formation into the peripheral blood. Cells of the erythrocyte series did not show chemotaxis.
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  • 167
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    The @Anatomical Record 159 (1967), S. 127-130 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A description is given of two intersex rabbits, which appeared to be females and, in the course of an experiment, were injected with chorionic gonadotrophin, and then matted with a male. When the animals were sacrificed six days later, the reproductive system was found to be absent except for testes located in the abdomen. On histological examination of the gonads, large amounts of interstitial tissue were found, together with immature seminiferous tubules. The tubules contained large atypical cells, spermatogonia and Sertoli cells. The chromosome number and karyotype, as determined from bone marrow, were male in each case. The intersex pattern and the morphology of the large cells within the seminiferous tubules are discussed.
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  • 168
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    The @Anatomical Record 159 (1967), S. 171-177 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Kidneys of timed fetal and newborn mice of the C57BL stock were sectioned and stained with a modified Bowie technique. The juxtaglomerular cells, indentifiable by their granularity and position, were recognized rather late in fetal life  -  three or four days before birth. By the eighth day postpartum, the granular cells of the JGA had reached a peak of differentiation and closely resembled the adult JGA in their number, size, granularity, and position. The mesangial cell was often but not always granulated. The granular cell indices (G.C.I.) of fetal, newborn, and adult mice are compared. The high G.C.I. in fetal kidneys in our studies should account for the high renin titre found by others in fetal kidney extracts.
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  • 169
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: When portions of the cytoplasm of fibroblasts cultured from mouse embryo tissues are irradiated with heterochromatic microbeams of ultraviolet light, lymphocytes are attracted (Lymphotaxis) to the injured areas. The lymphocytes approach in the “hand mirror” shape characteristic of tissue cultures. On reaching the fibroblast, pseudopodia shoot out to “lick” the wound and then the lymphocyte “worms” its way across the cell. Only one lymphocyte contacts a fibroblast but the same one may make several passes. It is postulated that lymphocytes are cleaning the wounded area of undesirable irradiation products and/or applying healing substances to the wounded fibroblast.Irradiation of lymphocytes in portions of the cytoplasm fails to evoke responses from nearlby lymphocytes. Instead, the cytoplasm whirls around the nucleus as if the irradiation products can not leave the cell, resulting in convulsions and death.A technique is described by which relatively pure cultures of lymphocytes may be obtained from leukocyte cultures by selectively killing all granular leukocytes with excessive exposure to microbeams of ultraviolet light. Lymphocytes are harvested and introduced into fibroblast cultures to study experimental lymphotaxis.
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  • 170
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Proliferation of the mammary gland epithelium on days 2, 3, 4, 6, 8, 12, 16, and 19 pregnancy has been studied in mice, by means of radioautography. Each animal received an intraperitoneal injection of 25°c of tritiated thymidine and was killed one hour later. The inguinal mammary glands were processed for paraffin sectioning and radioautographs prepared using the dipping technique. The rate of mammary epithelial cell proliferation was quantitated for each animal by determining the percent of labeled epithelial cells in a large sample (〉 2000 cells) of cells (labeling index).The data showed that the proliferative activity of the mammary epithelium during pregnancy followed a bimodal distribution. The first evidence of a proliferative response to pregnancy was noted on day 3. By day 4, the labeling index reached a maximum of 25.3%. The labeling index declined on days 6 and 8 to 7.5% and 8.0% respectively. On day 12, the labeling index increased to 12.1%, then fell to 7.9% and 1.3% on day 16 and 19, respectively.Separate labeling indexes were determined for the interlobular epithelium (ducts) on day 12, 16, and 19. The data showed that the labeling indexes of the interlobular and intralobular epithelium during these stages of pregnancy were not significantly different. The correlation of the hormones secreted during pregnancy with the data on mammary epithelial proliferation is discussed.
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  • 171
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    The @Anatomical Record 158 (1967), S. 443-451 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Male Holtzman rats were fed large doses of vitamin A, D or A and D for 43 days. Sections of the tibia demineralized in EDTA were submitted to alpharadiography or stained by a variety of procedures, including mucopolysaccharide histochemistry. The results were as follows: (1)In hypervitaminosis D, slightly increased periosteal apposition of normal bone; greatly increased maturation of osteocytes with lacunar enlargement and confluence, interstitial metachromasia and loss of density (osteocytic osteolysis).(2)In hypervitaminosis A, large growth of abnormally stained cancellous bone at periosteum and stimulation of osteolysis in new and old bone.(3)In combined A and D hypervitaminoses, the peripheral apposition rate exceeded that induced by vitamin A or vitamin D alone. The new bone appeared fragile and this combined with increased osteolysis was responsible for a number of spontaneous fractures.
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  • 172
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A group of venous sacculations associated wth a system of glomerular arteriovenous anastomoses and numerous nerves lies adjacent to the vertebral artery. As thin walled extensions of a dural sinus, these ampullae are structurally capable of responding to changes in venous pressure. The function of their glomerular connections to branches of the vertebral artery is not apparent.
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  • 173
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    The @Anatomical Record 159 (1967) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 174
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    The @Anatomical Record 159 (1967), S. 249-253 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Five-day-old mouse blastocysts were transferred into the oviducts of recipients on the second day of pregnancy. S35 methionine was then injected into the recipients and the blastocysts and native 2-celled eggs were recovered six hours later. Radioautographs reveal that the blastocysts incorporate S35 methionine while exposed to the tubal environment to the same degree that they would in the uterus. However, the 2-celled eggs in the same oviducal environment incorporate little or no methionine. It is therefore concluded that the difference in the incorporation of S35 methionine is due to maturational changes in the blastocyst rather than to a deficiency of the labelled amino acid in the tubal lumen.
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  • 175
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Systematic experiments have resulted in a method of decalcification which, although specifically developed for cytological study of reptilian aural tissue, should be applicable to other problems involving electron microscopy of organic components of bone or tissues closely associated with bone. Reptilian otic capsules and control specimens of mammalian hepatic tissue were subjected to planned variations of fixatives and decalcifying agents, embedded, sectioned, and evaluated by light and electron microscopy. Additionally, applicability of the more satisfactory agents to other mammalian tissue was checked by limited testing on specimens from Mongolian gerbils. Acceptable results were achieved in tissues fixed in glutaraldehyde, and then decalcified in cold 0.1 M solutions of disodium or tetrasodium EDTA (adjusted to pH 7.2-7.4 with sodium hydroxide or versenic acid, respectively), containing 4.0% glutaraldehyde; following decalcification, specimens were washed in buffer, postfixed in osmium tetroxide, and embedded in epoxy resins with minor modification of standard techniques. Acceptable cytological detail and morphological relationships were retained, and extended treatment with the decalcifying solution did not apparently result in degradation of tissues.
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  • 176
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: This report describes lesions observed in excurrent ducts of the testis in 152 of 518 rats, in the course of studies concerned with cadmium-induced testis injury and the actions of selenium and zinc, separately and combined, in protecting against such damage. All elements were injected subcutaneously, as soluble salts. Necropsy was usually five days (77% of rats) after cadmium injection, but lesions were observed within six hours.Ductuli efferentes showed variable degrees of sperm blockage, epithelial hyperplasia and metaplasia, periductal round cell infiltration, fibrosis and contraction. In 56 of 93 rats showing only ductuli lesions, testes were either normal or exhibited dilation of the rete testis and of variable numbers of seminiferous tubules, with or without “pressure degeneration” of the germinal epithelium. In the other 37 rats, the testes showed cadmium-induced injury.Lesions involving both ductuli efferentes and proximal segments of the caput epididymis (13 rats), or the latter alone (46 rats), tended to be associated with more severe testis damage. Epididymal lesions were characterized by focal proliferation and desquamation of duct epithelia, and formation of spermatoceles.The lesions observed were attributed primarily to ischemia, secondary to effects of cadmium upon the capillary bed of the tissues involved. However, their possible enhancement or modification by direct chemical action of cadmium, selenium or zinc upon the duct system or perivascular tissues could not be excluded.
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  • 177
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Measurements of volume of the anterior pituitary and diameter of pituitary cells and differential counts of acidophilic and basophilic cells were made under normal or experimental condition of bilateral or unilateral adrenalectomy or bilateral thyroidectomy in late fetal and newborn rats. The pituitary volume showed a consistent rise from the twentieth day of pregnancy to the third day after birth, but not as rapidly relatively as did body weight. Just after birth, the cell diameter declined. Acidophilic and basophilic cells increased in per cent and stained more intensely.In fetuses, bilateral adrenalectomy caused an increase in both the “pituitary volume/body weight” ratio and the cell diameter. Unilateral adrenalectomy caused an increase in the cell diameter. Thyroidectomy showed an increase in both the cell diameter and the per cent of basophilic cells which were partially degranulated.In newborns, bilateral adrenalectomy caused the death of all operated rats. Unilateral adrenalectomy caused no significant change in all categories observed. Thyroidectomy showed an increase in per cent of basophilic cells, but not to the extent observed in fetuses. The basophilic cells were somewhat degranulated.The observations support the views that in the rat the pituitary-adrenal and pituitary-thyroid systems begin to function before birth and that the functioning of both systems is slightly reduced just after birth.
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  • 178
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Parietal cells of the fundic region of the stomach in the golden hamster (Mesocricetus auratus) contain numerous electron-dense bodies which have different morphologies. Granular dense bodies are the most common, with lamellar and crystalloid forms less frequent; angular dense bodies with bizarre profiles are seen rarely. In random counts on sections of identical thickness, profiles of electron dense bodies averaged five per cell section and as many as 20 to 30 per cell section are found occasionally. These structures bear a striking resemblance to lysosomes described by other workers. Electron microscopic studies were made of frozen sections of the stomach incubated in Gomori's substrate mixture. Results indicated a discrete localization of acid phosphatase reaction products within the dense bodies. Studies on glutaraldehyde fixed material without further fixation in osmium tetroxide demonstrate features not readily discernable with standard osmium fixation.
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  • 179
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The population dynamics of the jejunal epithelium of mice maintained on a semi-synthetic diet deficient in the essential fatty acids (EFA) has been investigated. Colchicine was employed to collect mitotic figures for the determination of mitotic indices. Twenty-five crypts in longitudinal section were counted per animal and the mean mitotic index computed as the number of mitoses per total number of crypt cells. EFA-deficient animals had a mean mitotic index of 36.56 as compared with 26.51 and 16.74 for the linoleic acid-supplemented and chow-fed control animals, respectively. Counts of the number of epithelial cells on one side of a villus and crypt indicated that the height of the villi, but not the crypts, of the EFA-deficient animals was significantly lower than either control group. In the EFA-deficient animals the mean percentage of villi having extrusion zones exceeded that of both control groups. Radioautography demonstrated that 36 hours after injection of tritiated thymidine the majority of villi in the EFA-deficient animals were labeled at their tips, whereas in control samples label was restricted to the lower one-half to three-fourths of the villus. Thus, EFA-deficiency induces increased rates of mitosis, migration and sloughing, resulting in alterations in villous architecture.
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  • 180
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    The @Anatomical Record 159 (1967), S. 159-169 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Horseradish peroxidase was injected into the spleens of mice and the animals were sacrificed ten minutes after injection. The tissues were reacted with 3-3′ diaminobenzidine hydrochloride and the distribution of the reaction product was studied with both the light and electron microscope. The peroxidase was localized between epithelial cells up to the region of the tight junction and within vacuoles in the absorptive cells Granules ranging in size from ca. 40A to 600A were observed in the cytoplasm of epithelial cells in numbers far in excess of that found in control specimens. It appeared that the diffuse light brown staining observed in epithelial cells with the light microscope could be attributed to large numbers of granules of reaction product free in the cytoplasm. When corn oil was given by stomach tube and an intravascular injection of perioxidase was given ten minutes later, absorbed lipid was found to pass from interepithelial cell spaces to lamina propria at the same time that peroxidase was traversing the same compartments in the reverse direction. Hence, it was shown that exogenous peroxidase and probably other substances of vascular origin required for the metabolism of epithelial cells are exposed to both the basal and lateral epithelial cell membranes, even when absorbed lipid is traversing the same spaces in the opposite direction.
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  • 181
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    The @Anatomical Record 159 (1967), S. 211-218 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Silicone rubber microvascular injection compounds have been used to describe the mucosal vascular architecture of the monkey's small intestine. The mucosal vascular patterns of this animal differ from the classical description. Instead of the villus blood supply being delivered via a central villus arteriole, the arterioles ramify to the undersurface of the mucosa where they terminate in the capillary plexus surrounding the crypts of Lieberkuhn. The villus capillary net is derived directly from the cryptic capillary plexus and is drained by a single, central villus vein. There is a secondary venous return system that directly drains the cryptic plexus. These secondary venous channels might represent a mechanism that regulates the proportional distribution of blood in the cryptic and villus capillary beds.This report is intended to describe the vascular patterns only as they occur in the monkey. Observations of rat and rabbit mucosa prepared by the same technique reveal arterial and venous channels extending the length of the villi. These animals, therefore, more closely resemble the classical description.
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  • 182
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    The @Anatomical Record 159 (1967), S. 231-237 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The primordia of boundary (basement) membranes are present in the freshly laid egg along the basal surface of the epiblast. This location provides boundary membranes for all ectodermal derivatives including the central nervous system. Entodermal boundary membranes begin to form during the first half of the second day and eventually serve all entodermal derivatives. Mesodermal boundary membranes are slower to form. Those around the myotomes undergo considerable remodeling before the adult arrangement is reached. Endothelial boundary membranes are very slow to develop, not having appeared at 36 hours incubation.
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  • 183
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    The @Anatomical Record 159 (1967), S. 255-261 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Microradiographs of 100-300 μ slices of dog lungs which had pulmonary veins injected with barium sulphate showed good filling of brochial veins. Bronchial veins joined pulmonary veins at frequent intervals along the longitudinal axis and around the circumference of bronchi. Frequently, pulmonary veins and pulmonary capillaries entered the bronchial venous system, suggesting venous flow from lung to bronchus. Single veins along the margin of small bronchi (1 mm) received both pulmonary venous and bronchial venous blood. Therefore, there was a particularly intimate relationship between pulmonary and bronchial veins. The submucous venous plexus was prominent and was composed of thin-walled, 50 μ-diameter veins which had surprisingly direct connections to pulmonary veins. The proximity of a large venous plexus to the airway lumen suggested that oxygen transport could occur, thereby reducing venous admixture of the arterial blood.
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  • 184
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    The @Anatomical Record 159 (1967), S. 273-279 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The activity of alkaline phosphatase, acid phosphatase, glutamic-oxalacetic transaminase (GOT), lactic dehydrogenase (LDH), amylase, succinic dehydrogenase (SDH), glucose-6-phosphate dehydrogenase (GD) has been determined in the rabbit endometrium at estrus, in pseudopregnancy, and at days 5-10 of pregnancy. Enzyme analyses were also made on the placenta and embryo during early pregnancy.The most striking changes were increases in the SDH and GDH levels of the endometrium and a decrease in amylase when the does became pregnant or pseudopregnant. Amylase did not rise significantly from its lower level between five and ten days of pregnancy; SDH and GDH activity, however, fell away after reaching a maximum prior to implantation. At implantation there was some evidence of an increase in LDH and phosphatase activity. All enzymes had lower activities following implantation (10 days pregnancy). The endometrial enzyme activities of prepubertal does were usually similar to those of adult females in estrus. However, alkaline phosphatase activity of the prepubertal endometrium was particularly low.The activity of enzymes in the placental areas were, in general, similar to those found in the interplacental areas of the endometrium. However, from 7-10 days of pregnancy the activity of SDH was lower in the placental area than in the interplacental areas; whereas, amylase was higher on the eighth and ninth days of pregnancy. Changes in the activities of the phosphatases, GOT and SDH occurred in the blastocyst and trophoblast on eight to ten days of pregnancy. Enzyme activities in blastocoelic fluid were much less than in the trophoblast with the exception of amylase which was higher.
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  • 185
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The time of intrauterine migration and spacing of embryos was determined in 36 gilts with one oviduct occluded, and in 48 gilts with one ovary. Embryos could enter the uterus from one oviduct only. Uteri of seven pregnant gilts were examined on each of days 6, 7, 8, 9, 10, 11, 12, 13, and 15 of gestation. Migration of embryos from one horn to the other usually occurred first on day 8 or 9. The uterus was occupied completely by day 15. Rate of migration and distribution of embryos was not affected by number of embryos, number of corpora lutea, or by uterine length. Uterine length did not change between days 6 and 15. Bilateral ovariectomy after breeding was associated with arrested growth of embryos, a decreased rate of embryo migration and a reduction in uterine length.
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  • 186
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The effects of excess thyroxine, thiouracil and thyroidectomy upon the ependymal cells of the subcommissural organ, the choroid plexus and the wall of the caudal part of the third cerebral ventricle in the adult male albino rats were studied. A total of 203 rats were used. Thiouracil and thyroxine were administered orally, thyroidectomy was performed by means of radioiodine. Thiouracil was seen to diminish the ependymal nuclear volume especially in the subcommissural organ and in the wall of the third ventricle. Similar effects were observed by thyroidectomy, though the change was significant only in the ependyma covering the wall of the third ventricle. Excess thyroxine, again, increased nuclear volume of all ependymal cells studied. The changes could be observed over a period of 4-18 days. The signs of a return to normal after withdrawal of thyroxine and thiouracil were perceived after four days. Visual estimation revealed no clear change in aldehyde-fuchsin-positive “secretory material” in the subcommissural organ of any test group. The functional significance of the results is discussed.
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  • 187
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    The @Anatomical Record 157 (1967), S. 1-1 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 188
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    The @Anatomical Record 157 (1967) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 189
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    The @Anatomical Record 157 (1967), S. 19-25 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Antiserum to human chorionic gonadotropin (anti-HCG) with measured capacity to inhibit its antigen was used in conjunction with HCG in intact immature and in hypophysectomized female rats to determine if this hormone has intrinsic follicle stimulating properties. In intact rats, 100, 200, 500, 1000, 1500, 2000 and 2500 I.U. of HCG were given alone and in conjunction with anti-HCG. In hypophysectomized rats, 400, 800, 1600, 3200, and 6400 I.U. of HCG were given alone and with anti-HCG. Anti-HCG inhibited both the second rise in ovarian weight in intact females and follicular development in hypophysectomized females in a manner anticipated on the basis that these responses depended upon the HCG molecule. In hypophysectomized females inhibitition of follicular growth preceded inhibition of interstitial cell development. This result is also in accord with the view that both of these responses depend upon the HCG molecule.The anti-HCG serum did not inhibit synergism between HCG and NIH-FSH-S1, an ovine pituitary FSH, with doses of 100 and 200 I.U. of HCG combined with 240 m̈g of FSH. An amount of antiserum which would inhibit 500 I.U. of HCG augmented rather than inhibited the response to 1000 μg of NIH-FSH-S1 (43 mg ovarian weight as compared to 29 mg).We conclude from these data that the HCG molecule has intrinsic follicle stimulating properties.
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  • 190
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    The @Anatomical Record 157 (1967), S. 47-52 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Previously it had been demonstrated that daily injections of testosterone propionate (T.P.) will not induce male-like mounting nor clitoral hypertrophy in pregnant guinea pigs to the extent it will in non-pregnant females. In addition, administered progesterone had been shown effective producing a similar behavioral, but not somatic, “protection.” In an attempt to clarify the relationships of endogenous progesterone producing organs and this antiandrogen protective phenomenon the behavioral and somatic responses of females ovariectomized while pregnant and females hysterectomized (made pseudopregnant) while non-pregnant were studied.Guinea pigs were hysterectomized on the sixth day of their ovarian cycle and ovariectomized 60 days later. Additional groups of females were mated and then ovariectomized on the thirty-sixth or forty-sixth day of gestation. Groups of normal pregnant females, aborted females, and sham operated controls were also studied.All groups received daily injections of T.P. starting on the eighteenth day of pregnancy and continuing for the duration of the experiment (116 days). With these androgen treatments masculinization or protection from maculinization was evaluated on the basis of periodic sex behavior tests and on the basis of daily inspection of the external genitalia.The results indicate that protection from testosterone propionate-induced virilization is offered by exogenously administered progesterone as well as by an endogenous progestagen-producing structure such as the corpora lutea of the ovary in a hysterectomized female or the placenta in a pregnant animal. Some factor other than progesterone production is involved and the neural and somatic tissues exhibit different response thresholds.
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  • 191
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Lordosis responses on the day of birth were measured in female pseudohermaphrodites, their male siblings, and control females and males. All subjects displayed lordosis. Differences in average duration of the response were not significant.Relationships between exogenous estrogen and display of lordosis at later ages were studied in gonadectomized subjects. At seven days, estrogen did not induce lordosis in any subject. All normal females displayed lordosis at 21, 35, 60, and 90 days, and estrogen-sensitivity increased steadily. Pseudohermaphrodites failed to respond to hormones until 35 days, and responses were infrequent and abbreviated. Age at time of ovariectomy did not influence performance of pseudohermaphrodites. Males showed lowest responsiveness to estrogen over all ages.Pseudohermaphrodites resembled the male in postnatal responsiveness to androgen. Although postnatal testosterone induced mounting behavior in normal females, pseudohermaphrodites, like males, displayed more mounting and mounted at earlier ages.Results suggest that prenatal androgen has not impaired the neural mechanism for lordosis at birth. Rather it acts to alter, during the fetal stage, the mechanism which normally directs the development of estrogen-sensitivity of the neural mechanism in the genetic female. Additionally, prenatal androgen lowers the hormonal threshold for mounting behavior.
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  • 192
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Previous studies have shown that pentobarbital administration at 2 p.m. of proestrus in the rat blocks ovulation and the drop in pituitary LH content normally seen at estrus; these data were interpreted as indicating that the drug acted by blocking LH release. Signs of prolongation of estrogen secretion were seen in these rats and, in the absence of further treatment, ovulation occurred 24 hours later. In the present study a single dose of anti-ovine-LH-serum administered at 1 p.m. of proestrus also blocked ovulation, but did not prevent the drop in pituitary content on the moring of “estrus.” Therefore, one may conclude that this blockade was the result of preventing the peripheral effects of LH on the ovary. The antiserum blockade did not produce prolongation of estrogen secretion and no rat ovulated within the next four days. During this time pituitary LH content was normal, as were ovarian and uterine weight, although large follicles, rather than recent corpora lutea, were seen in the ovary. Six rats were followed until the next vaginal cornification (by 6 days); only three of the six had ovulated by day seven. The contrast between the sequelae of pentobarbital and antiserum blockade is interpreted in the light of a new theory of regulation of reproductive cyclicity in the rat.
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  • 193
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    The @Anatomical Record 157 (1967), S. 181-189 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Prepubertally castrate female rats are capable of showing the lordosis response when given replacement therapy with female sex steroids, regardeless of age at which the ovaries are removed post birth, or when replacement therapy is commenced after adulthood. Estrogen alone is reraly a sufficient stimulus for behavioral estrus. Therefore the natural physiological trigger for estrous behavior in the rat is likely estrogen plus progesterone. Prepubertally castrate male or female rats never showed any male or female behavior following androgen implant in the brain. All rats castrated on day three or ealier, and given implants of estrogen plus progesterone in the preoptic hypothalamic area displayed the lordosis response. Thus the female sex response pattern is present in both sexes in the absence of gonadal hormones from birth. Brain development in the male castrate at birth does not appear to be identical to brain development in the female castrate at birth because a number of males showed the complete male sexual response pattern plus the female response pattern following neural implant of estrogen plus progesteron. The genotypic male thus appears to possess the information necessary to produce the neural connections for male and female sexual response patterns. Androgen acting at birth disrupts the development of the feminine response pattern so that the adult male ordinarily displays only the copulatory pattern.
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  • 194
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    The @Anatomical Record 157 (1967), S. 191-196 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Histological characteristics of testis tissues from 25 African elephants (Loxodonta africana) collected in Uganda, showed no consistent relationships among the following variables: Leydig cell size, cytoplasmic characteristics, and abundance; testicular testosterone content; and age. From these findings, plus field observations of sexual behavior, emerges the hypothesis that individual cyclicity in Leydig cell function was inherent in the elephant population studied. Testosterone content of testes from 32 elephants (including the 25 studied histologically) suggested that lone bulls were not of a senile nature since they contained relatively large quantities of testosterone and were relatively young (from about 12 to 25 years of age). Also, lone bulls were observed searching out estrous females. Among bulls collected from family units and herds, testosterone levels and behavior differed conspicuously. Behavior appeared to be directly related to testosterone content in several instances. Nonaggressive behavior among members of bull herds, plus the high proportion of such aggressive behavior among members of bull herds, plus the high proportion of such individuals with low testosterone content, suggest that some of these animals were in a depressed phase of sexual activity whereas others were undergoing pubertal development.
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  • 195
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Portions of pancreases were removed from nineteen and one-half day fetuses from diabetic and nondiabetic rats. These explants were grown for four days in organ culture by the watch glass method.Four types of culture media were used: standard medium containing 165 mg of glucose per 100 ml; similar standard medium supplemented with 0.70 to 2.20 mU per ml of insulin (beef); high glucose medium containing 1050 mg of glucose per 100 ml; similar high glucose medium supplemented with 0.65 to 2.00 mU per ml of insulin (beef).In cultures of pancreases grown on standard media both with and without added insulin, there were large increases in the number of granulated beta cells.In cultures of pancreases of fetuses from diabetic rats, which were grown on high glucose medium, the high level of glucose maintained the cultures in a simulated diabetic environment in which few granulated beta cells appeared. Conversely, when the cultures of fetuses from diabetic rats were grown on high glucose medium with added insulin, there was an increase in the number of granulated beta cells.These observations suggest that the insulin level in the culture medium influences the granulation of the beta cell.
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  • 196
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    The @Anatomical Record 157 (1967), S. 449-456 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Body and organ weights of 24 newborn dogs and 35 newborn cats were studied. All of the measurements, except weights of hypophysis, spinal cord and testes are larger in the dogs. As percentages of body weight, the organs are more equally divided, with seven organs relatively heavier in the dogs and eight in the cats. All except two of the measurements of the newborn dogs are more variable than in the newborn cats.All of the organs are significantly correlated with body weight in the dogs and all except one, in the cats. All 15 of the organs are significantly correlated with body length in the dogs and 13, in the cats. The intercorrelations of the organ weights are somewhat higher in the dogs.The coefficients of variation of the newborn are compared with similar coefficients in adult dogs and cats. Body weight, body length and the kidneys are more variable in the adult dogs and the other organs, so far as data are available, are more variable in the newborn dogs of both sexes. Seven organs are more variable in adult male cats and three in females. The newborn dog is more variable in body and organ weights than the newborn cat, but weights of body and organs are better correlated in the newborn dog than in the newborn cat.
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  • 197
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    The @Anatomical Record 157 (1967), S. 465-479 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Endometrial acid and alkaline phosphatases were studied histochemically in rhesus monkeys treated with various combinations of estrogen (E, 17β-estradiol and/or estriol), progesterone (P) and relaxin (R) or a low potent relaxin control preparation (NRF). In the cells of the uterine glands of the E-treated animal, the apical cytoplasm showed intense activity of both phosphatases. This estrogenic response was depressed in the stratum functionale by P and in the stratum basale by PR. With E, acid phosphatase-staining granules appeared in scattered stromal cells with eccentric nuclei. Addition of P or PR increased the number of acid phosphatase positive stromal cells, especially in the stratum functionale. With the exception of the sinus-like channels and superficial vessels of the stratum functionale of monkeys treated with ER and EPR, all endothelium of capillary and precapillary vessels was rich in alkaline phosphatase activity. Thus, acid alkaline phosphatases appear to be metabolically important components of the endometrium which undergo cyclic variation and reflect specific influences of the ovarian hormones; estrogens, progesterone and relaxin. The implications to human menstrual physiology are discussed.
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  • 198
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Normal pelvic dimorphism is the result of the male pelvis acquiring morphological features during postnatal development that differ from those of the female. The first dimorphic features appear at 32 days of age. At 76 days of age the male pelvis has eleven dimorphic features that constitute the dimorphism of the normal adult. The development of five of the 11 features is dependent on the presence of the testes, whereas, the other six develop independently of the testes. The testes-dependent features develop in males castrated at birth and treated with testosterone. The postnatal development of the female-type pelvis in the normal female is not dependent on the presence of the ovaries.
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  • 199
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Radioautographs of the interscapular brown fat of six weeks old animals showed that within 24 hours after cold exposure at 4°-5°C, proliferation increased in endothelium of the already profuse capillary network and also that of arterioles and especially that of venules. This continued at a high level for 48 hours then declined. Extravascular fat precursor cells but not fat cells showed an increased proliferative activity at 48 hours cold exposure which continued until 96 hours. By eight days, adaptation to the cold occurred and proliferative activity was not increased thereafter nor did it occur significantly in animals seven months old. Animals exposed to cold 48 hours, given thymidine-H3, and then returned to a temperature of 23°C for a week or more showed a considerable number of labeled fat cells which presumably were precursor cells when the thymidine-H3 was given. When the interscapular brown fat was denervated on one side, there was no loss of lipid nor increased proliferative activity in the vascular or extravascular cells on that side after 48 hours cold exposure. The normally innervated opposite side, however, had more proliferating cells than usual, especially in the endothelium.
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  • 200
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    The @Anatomical Record 158 (1967), S. 59-73 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Oocytes of the hamster, rat, Mongolian gerbil and squirrel monkey demonstrate an unusual “twin” or multilaminated arrangement of the rough endoplasmic reticulum. Two or more cisternae appose laterally apparently after the ribosomes vanish from the adjacent surfaces. A central electron dense leaflet, composed of filamentous components can be discerned between the apposed surfaces. Between two cisternae of the membrane complex found in hamster oocytes, narrow connecting pillars or walls also develop. The nuclear envelope frequently represents one cisternal element in the membrane complex, at which place nuclear pores are lacking. In rat oocytes the endoplasmic reticulum cisternae take on either a concentric form, apparently by end-to-end fusion of “twin” cisternal membranes, or form a spiral by several turns of the same cisternum. No functional role could be suggested for the observed specilization of the endoplasmic reticulum.
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