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  • 1
    Electronic Resource
    Electronic Resource
    Ovarian sympathectomy in the guinea pig (1984)
    Springer
    Cell & tissue research 236 (1984), S. 257-263 
    Details
    ISSN: 1432-0878
    Keywords: Ovary ; Adrenergic nerves ; Follicle growth ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The influence of ovarian adrenergic nerves on follicular growth during the estrous cycle in the adult guinea pig was ascertained by comparing follicular development in control and chemically sympathectomized ovaries from the same animal. Selective ovarian sympathectomy was achieved by injecting 6-hydroxydopamine into a surgically closed periovarian membranous sac (bursa) on day 2 of the cycle (day 1 = day of estrus). The contralateral surgically closed ovarian bursa was injected with solvent used for 6-hydroxydopamine. Animals were laparotomized on days 5, 10 and 14 of the cycle. Blood from the utero-ovarian vein was collected bilaterally for measurement of progesterone and androstenedione. The ovaries were processed for histologic examination, and the number of follicles in each ovary was analyzed morphometrically. Sympathectomy on day 2 caused a decrease in healthy preovulatory follicles (〉 700 μm diameter) on day 10 of the cycle. There were no differences in ovarian weights or the total number of follicles per ovary at this time. On days 5 and 14 of the cycle, there were no differences in ovarian weights, total number of follicles per ovary or follicles in any size classification. Sympathectomy did not alter progesterone levels in the uteroovarian vein as compared to contralateral control levels. From control ovaries, there was a significant increase in progesterone in the blood of the utero-ovarian vein on day 10 but venous levels of progesterone from sympathectomized ovaries were not significantly different at any day of the cycle. In the venous effluent from sympathectomized ovaries, androstenedione was elevated at day 5 compared to days 10 and 14. These observations suggest that ovarian adrenergic nerves may modulate growth of large antral follicles and ovarian steroidogenesis during the estrous cycle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214226
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  • 2
    Electronic Resource
    Electronic Resource
    Ovarian sympathectomy in the guinea pig (1984)
    Springer
    Cell & tissue research 236 (1984), S. 593-596 
    Details
    ISSN: 1432-0878
    Keywords: Ovary ; Adrenergic nerves ; Follicle growth ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The role of ovarian adrenergic nerves in follicular growth was studied in prepubertal guinea pigs by determining the effect of sympathectomy on 1) follicle populations and 2) follicular development following exogenous gonadotropin administration. Selective unilateral ovarian sympathectomy was achieved by injecting 6-hydroxydopamine into a surgically closed periovarian bursa on day 20 postpartum. The contralateral surgically closed ovarian bursa was injected with the vehicle used for 6-hydroxydopamine. On day 25, animals were injected with pregnant mare serum or saline followed by human chorionic gonadotropin or saline 48 h later. All animals were laparotomized on day 28 and blood from utero-ovarian veins was collected bilaterally for androstenedione determination. Ovaries were processed for morphometric analysis of follicles. The sympathectomized ovary in saline-injected animals had a significant decrease in preantral follicles (characterized by ≤2 layers of granulosa cells without antrum formation), an increase in 310–500 μm diameter atretic follicles and an increase in follicles ≥700 um compared to the contralateral control ovary. There were no differences in androstenedione levels from the two sides, ovarian weights or the total number of follicles per ovary. Neither ovary had corpora lutea. The sympathectomized ovary in animals injected with gonadotropins was not different from the contralateral ovary in any of the parameters measured. Both control and sympathectomized ovaries had newly formed corpora lutea in response to the exogenous gonadotropins. These results suggest that ovarian adrenergic nerves normally participate in follicular development in the prepubertal guinea pig. However, exogenous gonadotropins may override neural influences on the prepubertal ovary.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217227
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  • 3
    Electronic Resource
    Electronic Resource
    An empirical approach to protein conformation stability and flexibility (1983)
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 49-58 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Experimental measurements of disulfide bond stability at various stages of protein folding are considered in terms of the effective concentrations of the thiol groups relative to each other; values of up to 107M are observed, so that intramolecular interactions within the interior of a protein are much more stable, and provide greater stability to the folded conformation, than those on the surface or in a flexible segment. Intramolecular interactions can have substantially lower free energies than intermolecular, for solely entropic reasons; this implies that polar interactions, such as hydrogen bonds and salt bridges, can provide net stabilization to a folded conformation, in spite of the unfolded protein having intermolecular interactions with the solvent. These considerations can account for the lower free energy and enthalpy of the folded state and are useful for considering protein flexibility.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360220110
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  • 4
    Electronic Resource
    Electronic Resource
    Application of corresponding states principles for prediction of self-diffusion coefficients in liquids (1980)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 26 (1980), S. 386-390 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A corresponding states approach has been used successfully to correlate reduced self-diffusivity of pure liquids with reduced temperature and acentric factor. In addition, dimensional analysis techniques have been used to accurately relate viscosity, normal boiling point and temperature with self-diffusivity, as well as to relate the three transport properties.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690260309
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  • 5
    Electronic Resource
    Electronic Resource
    Macrostructure and mechanical behavior of fibers of poly-p-phenylene benzobisthiazole (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 291-301 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Morphology and tensile behavior of wet-spun fibers of poly-p-phenylene benzobisthiazole have been investigated. The as-spun fibers contain a large number of voids, which result in void-localized tensile failure. The stress-strain behavior is elastic-plastic with strain hardening. This behavior is shown to be the result of residual stresses which arise during the wet-spinning process.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1981.070260127
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  • 6
    Electronic Resource
    Electronic Resource
    High performance epoxy resins cured in the presence of BF3 catalystPresented in part at N.A.T.E.C. Meeting, Oct. 25-27, 1982, Bal Harbour, Fla. (1983)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 28 (1983), S. 2227-2233 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Dynamic mechanical experiments have been conducted on an epoxy system made with tetraglycidyl 4,4′-diaminodiphenyl methane (TGDDM) and polyglycidyl ether of Bisphenol A Novalac that were cured with 4,4′-diaminodiphenyl sulfone (DDS) in the presence of Boron trifluoride monoethylamine catalyst (BF3:EtNH2). As the concentration of BF3:EtNH2 increased, the low temperature β-transition magnitude increased slightly. The α1-transition observed in the uncatalyzed system decreased significantly with the addition of BF3:EtNH2 catalyst. The α2 or glass transition temperature of this system increased with increasing catalyst concentration. Both the catalyzed and uncatalyzed epoxy formulations studied in this work are important due to their similarity to systems used commercially in epoxy matrix composites.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1983.070280709
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  • 7
    Electronic Resource
    Electronic Resource
    Spectres Raman de Résonance de Dérivés Substitués de l'Aminoazobenzéne en Solution Acide (1981)
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 11 (1981), S. 131-137 
    Details
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The resonance Raman spectra of aminoazobenzene derivatives in acidic solution are investigated. The marked spectral changes observed on decreasing pH are related to transformations between azo and quinoid forms. The pKa value of 4-amidino, 4′-diméthylaminoazobenzene obtained from intensity measurements is in good agreement with the value obtained from visible absorption measurements. Comparison of resonance Raman spectra of some substituted aminoazobenzene derivatives and the quinoid form of an hydroxyazobenzene derivative enable a more complete assignment of the bands observed between 900 and 1700 cm-1 to be made. All the spectra are rather similar and the various ring substituents are not resonance Raman active. The influence of the —NH—N = vibration on resonance Raman spectra of the quinoid forms is demonstrated using deuterium substitution. In strong acid solution a second protonation occurs; a tautomeric equilibrium between azo and quinoid forms of aminoazobenzene derivatives is demonstrated using different exciting laser lines.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jrs.1250110215
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  • 8
    Electronic Resource
    Electronic Resource
    Spectres Raman de Résonance de Dérivés Substitués de l'Hydroxyazobenzène en Solution Fortement Acide (1981)
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 11 (1981), S. 209-214 
    Details
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Resonance Raman spectra of azobenzene and some hydroxyazobenzene derivatives, in strong acid solution (HCI 6 M), are analysed. All the observed bands between 900 and 1700 cm-1 can be assigned to vibrational modes of the aromatic rings and the azo group, and give evidence for a trans azo type structure both for azobenzene and the para substituted hydroxyazobenzene derivatives studied. Resonance Raman spectra of six substituted 2-(4′- hydroxyphenylazo)-benzoic acid derivatives in strong acid solutions are investigated. The spectral features are rather different from the above studied hydroxyazobenzene derivatives, but can be explained on the basis of an azo type structure. A strong perturbation effect on the N=N stretching mode is demonstrated using deuterium substitution. From the complexity of frequency shifts obtained on deuterium substitution, vibrational coupling between NH bending and many other vibrational modes is evident. A tentative assignment of the observed resonance Raman bands is proposed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jrs.1250110311
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