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  • 1975-1979  (13)
  • 1979  (5)
  • 1978  (8)
  • Cell & Developmental Biology  (5)
  • Inorganic Chemistry  (4)
  • Physics  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Phosphorhaltige Kohlenhydrate, XVII: Untersuchung der Hydrierung ungesättigter Glycosylphosphonate. Anomerer Effekt und A-Wert der Dimethylphosphono-Gruppe (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 3325-3335 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Phosphorus-containing Carbohydrates, XVII: Studies on the Hydrogenation of Unsaturated Glycosylphosphonates. Anomeric Effect and A-Value of the Dimethylphosphono GroupBy hydrogenation unsaturated glycosylphosphonates of type 1 give rise to the formation of 2,3-dideoxyglycosylphosphonates 2 and 2,3,4-trideoxyglycosylphosphonates 3. Their product ratio depends on configuration and conformation of the educts 1a-f. 1H and 13H and 13C NMR data permit an assigment of the anomers of the hydrogenated glycosylphosphonates. For the one-bond coupling constant between 13C-1 and 31P the correlation 1JC, Peq 〉 1JC, Pax is valid, which exhibits a difference of 19-23 Hz. The unsaturated glycosylphosphonates show deviations from Hudson's isorotation rule. In dimethyl cis-4-methyl-1-cyclohexanephosphonate (9) the A-value of the dimethylphosphono group has been determined to 8.34 kJ/mol. The ratio of conformers in 3a leads to an anomeric effect of the dimethylphosphono group of 2.33 kJ/mol.
    Notes: Ungesättigte Glycosylphosphonate vom Typ 1 liefern bei der Hydrierung außer 2,3-Didesoxyglycosylphosphonaten 2 auch 2,3,4-Tridesoxyglycosylphosphonate 3. Das Produktverhältnis ist von Konfiguration und Konformation der Ausgangsprodukte 1a-f abhängig. 1H- und 13C-NMR-Daten erlauben eine Anomerenzuordnung der hydrierten Glycosylphosphonate. Für die 13C-31P-Direktkopplung an C-1 gilt 1JC, Peq 〉 1JC, Pax mit einer Differenz von 19-23 Hz. Die ungesättigten Glycosylphosphonate zeigen Abweichungen von der Hudsonschen Regel. Am Dimethyl-cis-4-methyl-1-cyclohexanphosphonat (9) wurde der A-Wert der Dimethylphosphono-Gruppe zu 8.34 kJ/mol bestimmt. Aus der Konformerenverteilung bei 3a ergibt sich der anomere Effekt der Dimethylphosphono-Gruppe zu 2.33 kJ/mol.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781111006
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  • 2
    Electronic Resource
    Electronic Resource
    Corpus luteum growth and plasma progesterone levels in unilaterally ovariectomized pregnant rats (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 195 (1979), S. 311-316 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Unilateral ovariectomy (ULO) was carried out on rats at Day 8 of gestation: term is Day 23. The effect on peripheral plasma progesterone levels at Day 16 and on growth and cellular changes in the remaining corpora lutea (CL) at Day 17 was determined by comparison with results from control and sham-operated rats. ULO increased the volume of remaining CL by 18% at Day 17. At Day 16 this effect was only apparent in rats with three or fewer CL remaining. CL hypertrophy was due to an increase in the volume of individual luteal cells and not to cell hyperplasia. Luteal cell nuclear volume also increased as did the number of endothelial cells per corpus luteum. The proportion of the corpus luteum occupied by vascular space did not alter.ULO had little effect on mean plasma progesterone levels at Day 16 (92 ± 7 ng/mltreated; 86 ± 11 ng/ml controls). In rats with three or fewer CL remaining, however, progeserone levels were low (51 ± 7 ng/ml).It was concluded that ULO can enhance the growth of corpora lutea and perhaps increase their rate of progesterone production.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091950206
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  • 3
    Electronic Resource
    Electronic Resource
    Cytological events associated with in vitro aged and fertilized rabbit eggs (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 195 (1979), S. 357-374 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The morphogenetic events associated with rabbit eggs aged in vitro for 12 to 50 hours prior to mixing with sperm have been examined by light and electron microscopy. After 12 hours in culture, morphological alterations of the meiotic spindle and the cortex of unfertilized eggs were evident. By 24 to 50 hours in culture, unfertilized eggs contained subnuclei, structures which formed when individual and/or groups of meiotic chromosomes dispersed and became invested by a double-laminated structure reminiscent of a nuclear envelope.Although most eggs obtained 11.5 to 12 hours after induced ovulation and in vitro fertilized displayed morphogenetic patterns similar to those described for in vivo fertilized ova, some (10%) contained three pronuclei. Many eggs obtained 13 to 15 hours after induced ovulation and subsequently mixed with sperm in vitro appeared to undergo processes of fertilization typical of in vivo fertilized eggs, however, approximately 30% contained subnuclei in association with the male pronucleus. Few eggs (15%) aged 12 hours prior to in vitro fertilization displayed patterns of pronuclear development and association typical of fertilized unaged ova. Subnuclei developed in many of the fertilized ova. Supernumerary sperm nuclei, which did not develop into male pronuclei, were observed in some zygotes. Cleavage of eggs aged 12 hours prior to fertilization was abnormal or retarded. After 24 hours in culture approximately 16% of the eggs fertilized. Seventy percent of the fertilized eggs failed to Support the development of a male or female pronucleus.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091950209
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  • 4
    Electronic Resource
    Electronic Resource
    The cellular pattern of corpus luteal growth during pregnancy in the rat (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 193 (1979), S. 823-830 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The cellular pattern of corpus luteal (CL) growth was studied in rats at Days 6, 10, 12, 14, 16, 17 and 22 of pregnancy: term is Day 23. Measurements were taken of the percentage of the CL occupied by luteal cells, connective tissue and vascular space, luteal cell and nuclear volumes, and the number of luteal and endothelial cells in each of three CL in both ovaries of five rats at each stage of pregnancy. Total CL volume increased from 1.08-3.23 μl over Days 10-17. This was mainly due to an increase in luteal cell volume from 3.72 pl to 9.30 pl. Neither the number of luteal cells per CL (range 212,000-287,000) nor the percentage of the CL occupied by luteal cells (range 85-90%) had much influence on growth. Nuclear volume increased roughly in proportion to cytoplasmic volume but near term it decreased despite little change in cytoplasmic volume. The number of endothelial cells per CL increased steadily from 398,000 at Day 6 to 1,545,000 at Day 22. There was a strong negative correlation (r = -0.78) between the number of luteal cells per CL and mean luteal cell volume that was evident at all stages of pregnancy. There was a positive, but weaker correlation (r = 0.35) between number of luteal cells and CL volume. Thus, CL volume seems to be partly determined by the number of luteal cells at Day 6 but this effect is moderated by local control of luteal cell volume.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091930406
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  • 5
    Electronic Resource
    Electronic Resource
    Microfilaments, the smooth endoplasmic reticulum and synaptic ribbon fields in the pinealocytes of the baboon (Papio ursinus)Supported by the Medical Research Council and the University of Pretoria. (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 154 (1979), S. 151-161 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Microfilaments (MF, 5-8 nm in diameter) are a prominent feature of the pinealocyte cytoplasm of baboons (Papio ursinus) kept under controlled lighting conditions. MF occurred as a filamentous network in these cells during the light phase of the diurnal light-dark cycle, while a close structural association was noted between MF and the membranes of the smooth endoplasmic reticulum (SER). This association was especially evident during the dark period. Increased numbers of single synaptic ribbons (SR, vesicle-crowned rodlets), together with large aggregations of SR, i.e., ribbon fields (RF), were seen in the pinealocyte cytoplasm of baboons killed during the dark phase. It is suggested that the vesicles of RF may arise from those of the SER and that MF may play a role in the movement of SER-vesicles to those areas of the cytoplasm where new RF are being formed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001540203
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  • 6
    Electronic Resource
    Electronic Resource
    Antibody-mediated suppression of bone marrow colony formation in vitroSupported in part by USPHS Grant AI 10931 from the National Institute of Allergy and Infectious Diseases and a grant from Smith Kline and French Foundation. (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 94 (1978), S. 47-56 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Antisera to mouse brain reacts with hematopoietic stem cells in the mouse bone marrow. We have examined the effect of anti-mouse brain serum (AMBS) on the development of in vitro colonies from mouse bone marrow cells. The addition of 5% AMBS to the cultures markedly decreased the numbers of colonies formed to an average of 10% of the number obtained with normal rabbit serum. AMBS suppressed formation induced by colony stimulating factors (CSF) derived from three different sources; serum from endotoxin treated mice, mouse L-cell conditioned media, and human peripheral blood mononuclear cell conditioned media. The suppressive activity was quantitatively recovered in the IgG fraction of AMBS. Divalent F (ab′)AHBS, rabbit anti-human brain serum; AMBS, rabbit anti-mouse brain serum; BM, bone marrow; CFU-C, colony forming unit in vitro; CFU-S, spleen colony forming unit; CSF, colony stimulating factor; FCS, fetal calf serum; MEM, minimal essential medium; NRS, normal rabbit serum; PBS, 0.01 M sodium phosphate, 0.15 M sodium chloride, pH 7.4. fragments were as effective as the intact IgG in decreasing colony formation. Fab fragments were not suppressive. These results suggest that colony formation is induced via a dynamic interaction between CSF and the progenitor cell membrane, and that antibody directed at cell membrane antigen(s) interferes with the generation of the induction signal.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1040940107
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  • 7
    Electronic Resource
    Electronic Resource
    Four-center photopolymerization. A heterogeneous topochemical solid-state reaction (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 16 (1978), S. 1365-1379 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The four-center solid-state photopolymerization of distyrylpyrazine (DSP) and of 2,6-naphthalene bis(acrylic acid-2,4-dichloro phenyl ester) (NBA-DCP) was investigated by x-ray and microscopic techniques. In both cases the polymer grows as a separate product phase topotactically well arranged with respect to the monomer matrix. In the case of polymerization of DSP the space group of the monomer (Pbca) is not maintained but the polymer phase has space group P21ca. Nucleation and growth of the polymer phase was observed by light and electron microscopy. Nucleation occurs at defect sites. The polymer grows at different rates in different crystallographic directions which were identified by electron diffraction in the case of DSP. Polymerization thus occurs in the transition region between monomer crystal and product phase and not in the bulk of the crystal so that the four-center-type photopolymerization is best described as a heterogeneous solid-state reaction.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.180160803
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  • 8
    Electronic Resource
    Electronic Resource
    Ion clustering in a butadiene, styrene, 4-vinylpyridine terpolymer crosslinked by coordination with iron(III) chloride (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 16 (1978), S. 569-581 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A butadiene, styrene, 4-vinylpyridine terpolymer has been crosslinked by coordination of the pyridine groups with iron chloride. The distribution and structure of the iron complexes have been studied. Electron microscopy has given evidence of clustering of the iron complexes. The size distribution of these clusters has been evaluated by small-angle x-ray and neutron scattering. Mössbauer spectroscopy and magnetization measurements have shown the presence of three different kinds of iron complexes: (a) complexes with a speromagnetic structure in the clusters previously found, (b) dimers with antiferromagnetic coupling, and (c) quasi-isolated complexes with weak ferromagnetic coupling. The percentages of these different iron complexes have been measured.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.180160401
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  • 9
    Electronic Resource
    Electronic Resource
    On the structure of glassy polymers. VI. Electron microscopy of polycarbonate, poly(ethylene terephthalate), poly(vinyl chloride), and polystyrene (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 16 (1978), S. 2005-2014 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: High-resolution electron microscopy studies have been carried out on four glassy polymers examined in previous small-angle x-ray scattering (SAXS) investigations. The polymers include polycarbonate, poly(ethylene terephthalate), poly(vinyl chloride), and polystyrene. For all four polymers, both bright field and dark-field observations indicate the general absence of microstructural features of a size down to the resolution limit of the electron microscope. Only “pepper and salt” features on a scale ca. 5 Å are seen as characteristic of the structures. These features reflect simple interferences as the resolution limit is approached, and are seen for single crystal and oxide glasses as well as for the polymers. The present results, taken together with structural information from light scattering, SAXS, and small-angle neutron scattering, indicate that glassy polymers should be regarded as having rendom structures. The combined results are inconsistent with heterogeneous microstructures having regions of locally high order present in large volume fractions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.180161110
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  • 10
    Electronic Resource
    Electronic Resource
    Method for viscosity measurements at high pressure (1979)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 17 (1979), S. 2225-2228 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The technique of quasielastic light scattering is utilized to determine the viscosity of fluids subjected to large hydrostatic pressures. In this method, a small concentration of insoluble polystyrene spheres of known diameter, 0.109 μm, is added to the fluid. The high-pressure cell in which the fluid is contained has three optical windows. The laser light scattered from the suspended spheres is analyzed to determine the diffusion coefficient of the spheres. Since, by the Stokes law, the viscosity of the fluid is determined from the measured diffusion coefficient and known particle radius r. A small correction is required for the contraction of the spheres and for refractive-index change of the water under pressure. Results on the viscosity of water at 25°C up to pressures of 2.5 kbar are reported and compared with published results. This method is applicable to lubricants and polymer solutions where the viscosity is many orders of magnitude greater than that of water.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1979.180171216
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