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  • 1970-1974  (504)
  • Cell & Developmental Biology  (243)
  • Inorganic Chemistry  (207)
  • Ultrastructure  (54)
  • 1
    Electronic Resource
    Electronic Resource
    Reactions between diisopropyl methylphosphonate and halides of divalent metal ions (1971)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 384 (1971), S. 267-279 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metall(II) Halogenide reagieren mit Diisopropyl Methylphosphonat (DIMP) bei 150-220°C unter Bildung der folgende Komplexe: M[(C3H7O)CH3POO]2 (M = Fe, VO); M2[(C3H7O)CH3POO]2[OOP(CH3)-O-P(CH3)OO], (M = Ca, Mn, Co Ni); Zn[OOP(CH3)-O-P(CH3)OO]; Cu[CH3POO(OH)]3 (aus CuCl2 · 2 H2O + DIMP); Cu[CH3PO3] (aus CuX2 + DIMP; X = Cl, Br). Diese Komplexe wurden mittels Elektronen- und Infrarot-Spektren und magnetischen Messungen charakterisiert.
    Notes: Metal(II) halides react -with diisopropyl methylphosphonate (DIMP) at 150-220°C with formation of the following complexes: M[(C3H7O)CH3POO]2 (M = Fe, VO); M2[(C3H7O)CH3POO]2[OOP(CH3)-O-P(CH3)OO], (M = Ca, Mn, Co Ni); Zn[OOP(CH3)-O-P(CH3)OO]; Cu[CH3POO(OH)]3 (from CuCl2 · 2 H2O + DIMP); Cu[CH3PO3] (from CuX2 + DIMP; X = Cl, Br). These complexes were characterized by means of their electronic and infrared spectra and magnetic susceptibilities.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19713840312
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  • 2
    Electronic Resource
    Electronic Resource
    Cell wall formation in zoospores of Allomyces arbuscula (1974)
    Springer
    Archives of microbiology 98 (1974), S. 147-158 
    Details
    ISSN: 1432-072X
    Keywords: Allomyces ; Zoospores ; Cell Wall ; Wall Formation ; Lomasome ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ultrastructural observations on encysting haploid zoospores of Allomyces arbuscula are presented with special reference to cell wall deposition. Multivesicular bodies are observed in the cytoplasm of zoospores 15 min after inoculation, lomasomes after 30 min and fine membrane profiles between the plasmalemma and the cyst wall are observed after 4 h indicating a possible system for secretion of cell wall components.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425277
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  • 3
    Electronic Resource
    Electronic Resource
    The hypothalamo-hypophysial system of hypophysectomized rats (1974)
    Springer
    Cell & tissue research 155 (1974), S. 541-554 
    Details
    ISSN: 1432-0878
    Keywords: Hypophysectomized rats ; Reorganized stalk ; Ultrastructure ; Salt load
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The reorganized stalk of hypophysectomized rats, either “intact” or subjected to a 6-day salt load, has been studied by light and electron microscopy. PAF-positive neurosecretory material is seen mainly in the periphery of the reorganized stalk, usually in 2–5 μ nerve swellings of animals operated two months before. Nerve swellings make contact with a dense capillary network. Three types of nerve fibres and their swellings are distinguished according to the size of elementary granules. Peptidergic A1 and A2 types contain granules with a maximum diameter of 170 and 130 nm respectively; monoaminergic B type fibres have granules of 100 nm in diameter. A1 type axonal swellings are the most numerous and can be tentatively divided into four subtypes according to their ultrastructure and relationships with capillaries and pituicytes. Swellings of types b and c, making direct contact with capillaries or pituicyte perikarya, usually contain few granules and numerous synaptic vesicles arranged frequently in clusters in the “active” zones. It is assumed that they are especially active in the release of peptide neurohormones. It is also hypothesized that in the hypophysectomized rats peptide neurohormones are released not only directly into the pericapillary space but also into the intercellular cleft, especially at sites of neuron-pituicyte junctions. Nerve swellings of type a, separated from the pericapillary space by thin pituicyte processes, usually contain numerous neurosecretory granules. It is suggested that vascular “end-feet” of pituicytes may somehow reduce neurohormone release. The depletion of PAF-positive material as well as the decreased granule content even after a salt load of only 1 per cent shows that the reorganized stalk is functional as a neurohaemal organ, but has a diminished hormone reserve. This, together with a primitive cytomyeloangioarchitecture speaks for morphological and functional imperfection of the reorganized stalk.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227014
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  • 4
    Electronic Resource
    Electronic Resource
    Le Systeme Tl2O—V2O5 (1974)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 410 (1974), S. 1-8 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Das System Tl2O—V2O5Das System Tl2O—V2O5 wurde mit Hilfe von thermischen Analysen und durch Röntgenanalyse untersucht. Das gesamte Zustandsdiagramm konnte aufgeklärt werden. Von den meisten erhaltenen Phasen wurden Einkristalle isoliert und die Gitterkonstanten durch Weissenberg und Präzessionsaufnahmen bestimmt. Die an Vanadium reichen Phasen sind mit den entsprechenden Kalium-Verbindungen isotyp. Die an Thallium reichen Phasen Tl4V2O7 und Tl3VO4 zeigen diese Isomorphie nicht, wahrscheinlich wegen der stereochemischen Rolle des einsamen Elektronenpaares des Thalliums(I).
    Abstract: The System Tl2O—V2O5The Tl2O—V2O5 system has been studied by thermal analysis and x-ray analysis. The entire phase diagram is reported. The symmetry and cell dimensions of most of the phases are derived from single crystal photographs. The compounds rich in vanadium are isomorphous with potassium analogues. Such an isomorphism does not exist for compounds like Tl4V2O7 and Tl3VO4; in these cases, the lone pair of thallium(I), doubtless, is stereochemically active.
    Notes: No Absstract.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19744100102
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  • 5
    Electronic Resource
    Electronic Resource
    Untersuchungen zur Dispersität des Platins auf Aktivkohlen mit unterschiedlicher Porenstruktur (1972)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 389 (1972), S. 43-56 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The influence of the porous structure of thr carrier on the dispersion of the catalytically active platinum has been investigated on charcoal catalysts with a content of five percent platinum.Three samples were characterised by adsorption measurements, mercury porosimetry and X-ray small angle diffraction. Their preparation was carried out by impregnation with two different platinum complex compounds under varying the conditions. The dispersion is strongly influenced by the adsorption of the impregnated compound on the carrier surface. The good adsorption of the compound H2PtCl6 leads to highly dispersed platinum, the bad adsorption of Pt(NH3)4Cl2 causes the platinum to be only coarsely dispersed on the surface. Varying the conditions of preparation during impregnation with H2PtCl6 gives no effect, the porous structure of the carrier, however, has a strong influence on the dispersion i. e. microporous carriers yielding highly dispersed platinum, with a high part of the platinum in the micropores.
    Notes: Am Beispiel von 5proz. Platin-Kohle-Katalysatoren wurde der Einfluß der Porenstruktur des Trägers auf die Verteilung des katalytisch aktiven Platins untersucht. Dazu wurden verschiedene Kohlen eingesetzt, deren Porenstruktur durch Adsorptions-, Quecksilberporosimetrie- und Röntgenkleinwinkelmessungen charakterisiert wurden.Die Kontaktherstellung erfolgte durch Tränkung mit zwei verschiedenen Platinkomplexverbindungen. Auch die Bedingungen der Kontaktherstellung wurden variiert.Die Dispersität wird in erster Linie von der Adsorption der Tränkverbindungen auf der Trägeroberfläche bestimmt. Im Falle guter Adsorption der Tränkverbindung (H2PtCl6) auf der Trägeroberfläche werden hohe Platindispersitäten erzielt, im Falle schlechter Adsorption der Tränkverbindung (Pt(NH3)4Cl2) ist das Platin nur in grobdisperser Form auf der Trägeroberfläche verteilt. Bei guter Adsorbierbarkeit der Tränkverbindung haben die Herstellungsbedingungen keinen wesentlichen Einfluß, aber die Porenstruktur des Trägers hat einen großen Einfluß auf die erzielbare Platindispersität. Auf mikroporösen Trägern wird eine hochdisperse Platinverteilung erreicht, wobei sich ein großer Teil des Platins in den Mikroporen befindet.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19723890106
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  • 6
    Electronic Resource
    Electronic Resource
    Fine structure of eyespots in tornarian larvae (Phylum: Hemichordata) (1973)
    Springer
    Cell & tissue research 142 (1973), S. 89-102 
    Details
    ISSN: 1432-0878
    Keywords: Photoreceptors ; Larva ; Hemichordate ; Ultrastructure ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The eyespots of tornariae of enteropneusts (Ptychodera flava from Hawaiian waters and an unknown species from southern California) were studied by electron microscopy. An ocellus is composed of two types of cells: sensory and supportive. The former is characterized by a bulbous cilium (with 9+2 axoneme) at its distal end, one or sometimes two arrays of microvilli from its sides below the cilium, and a basal axon. The latter features large, clear vesicles which presumably contained the reddish-orange pigment seen in the ocellus of a living larva. Five-day old tornariae of P. flava are positively phototactic. Both cilium and microvilli may function as photoreceptors. The tornarian ocellus studied is compared with eyespots of other invertebrates, and the evolutionary significance of its putative photoreceptors is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306706
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  • 7
    Electronic Resource
    Electronic Resource
    Corticotrophic cells in the rostral zone of the pars intermedia and in the adjacent neurohypophysis of the rat and mouse (1973)
    Springer
    Cell & tissue research 136 (1973), S. 97-110 
    Details
    ISSN: 1432-0878
    Keywords: Hypophysis ; Mouse, rat ; Pars intermedia, rostral zone ; Corticotrophic cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the mouse, the rostral zone of the pars intermedia is almost exclusively composed of typical corticotrophic cells. They are located around and even within the neural stalk, at the level of transition between stalk and neural lobe. In the rat, the corticotrophic cells of the rostral zone are found in scattered islets among the MSH producing cells, and also in the neural lobe. In both the rat and mouse, these cells are in direct contact with various types of nerve terminals. Synaptoid contacts with aminergic and neurosecretory nerve fibers are observed. Furthermore they are also closely related to the hypophysial portal vessels. Following adrenalectomy, the cells located in the neurohypophysis always react more intensely than tose in the rostral zone. The functional significance of these corticotrophic cells which are subject to both humoral and neural regulation remains as yet hypothetical. Their participation in neurogenic stress response seems probable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307682
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  • 8
    Electronic Resource
    Electronic Resource
    Suppression of the allograft response by implants of mature lymphoid tissues in larval Xenopus laevisSupported in part by a grant (CA-08268) of the National Cancer Institute, National Institutes of Health, Bethesda, Maryland. (1972)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 138 (1972), S. 457-465 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: One hundred and twenty-two larvae of Xenopus laevis, the South African clawed toad, at developmental stages 48, 50, 52 and 54, were implanted in the tail with two allografts from adult tissues. In each case, one allograft was from kidney, while the other was either from kidney, thymus, spleen, or liver. In any particular host the two implants were always from the same donor and the implants were all visually matched in size. The experimental period was a maximum of nine days, so as to minimize the large numbers of changes normally accompanying larval progress from stage to stage. We are concerned with the timing of allograft response initiation under the implant conditions of each experimental group at a particular point in development. An allograft response was defined as an infiltration and accumulation of small lymphocytes in the “test” kidney allograft. Larvae of all stages developed allograft responses within one week post-implantation when the variable implant was from kidney, but implants from spleen and thymus suppressed both the timing of initiation and the subsequent intensity of the response. Spleen was more effective in this regard than thymus and both were more effective in the earlier larval stages. Liver proved to be toxic to the larvae. The relationship between the maturation of the lymphomyeloid tissues and external morphological staging is also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051380406
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  • 9
    Electronic Resource
    Electronic Resource
    The development of the chondrocranium of the lacertid lizard, Acanthodactylus boskiana (1972)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 137 (1972), S. 289-333 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The trabeculae cranii are at first quite separate from each other, after few days their anterior two fifths are connected by a trabecular plate which is obliterated throughout development. The paired origin of the parachordal plate is not observed. The fused posterior orbital cartilages chondrify in the form of a wide short plate, traversed by the oculomotor and trochlear nerves. The basicranial fenestra and fenestra ovalis are formed by the degeneration of pre-existing cartilage. The cochlear portion is completely fused with the parachordal plate from the very beginning. The elements of the pterygoquadrate are fused together. The quadrate and Meckel's cartilage are in close contact from the very beginning. While the lower part of the interorbital septum is derived from the trabecula communis, its upper part is derived from the anterior orbital cartilages. The lateral parts of the fused posterior orbital cartilages give rise to most of the taeniae and pilae of the orbitotemporal region. There is only one commissure between the auditory capsule and parachordal plate. A cartilaginous connection between the distal portion of the columella auris and ceratohyal persists for some time. The parietotectal and paranasal cartilages are fused together from the very beginning. The processus paroticus originates from the columella auris.In the fully formed stage the notochord is completely embedded in the occipital condyle. The union between the condyle and odontoid process persists. The auditory capsules and occipital arches contribute to the formation of the tectum synoticum plus posterius. The prefacial commissure and facial foramen lie in front of the cochlear portion. The columella auris possesses a processus internus (connected with the quadrate), but the processes a dorsalis has completely disappeared. The orbitotemporal region is quite complete. A medial fenestra is formed in the planum supraseptale. A fenestra is observed in each of the interorbital and nasal septa. The lamina transversalis anterior is fused with the parietotectal cartilage. A complete zona annularis is present. The outer wall of the paranasal cartilage is perforated by a large fenestra lateralis. The parietotectal and paranasal cartilages and the posterior process of the lamina transversalis anterior contribute to the formation of the concha nasalis. There is a contact between the planum antorbitale and nasal septum. The pterygoid process has disappeared. The common characters of the lacertid chondrocranuium are deduced.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051370304
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  • 10
    Electronic Resource
    Electronic Resource
    Alterations in the epithelial surface of A/Jax mouse palatal shelves prior to and during palatal fusion: A scanning electron microscopic studySupported in part by NIH grant DE-02987 to L. M. Ross, and NIH grants DE-01766-10, DE-00278-02 and Ford Foundation grant 710-0036. (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 176 (1973), S. 361-375 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The surfaces of palatal shelves from carefully staged A/Jax mouse embryos were examined with the scanning electron microscope prior to and during palatal fusion. No change was observed in the appearance of cells covering the oral and nasal surfaces of the shelves. A change was observed, however, in the region of presumptive fusion, and was detectable on vertical shelves just prior to transposition. This change initially involved surface cells along the future medial edge of the shelf at the level of the second to third rugae. It was characterized by a loss of distinct cellular boundaries, the appearance of intercellular gaps caused by apparent retraction of adjacent cells, and a progressive accumulation of filamentous material at the surface. These alterations spread posteriorly along the medial edge of the shelf during transposition and fusion. While it was impossible to determine the precise nature of the surface change from S.E.M. data alone, the fact that it both preceded closure and was restricted to the region of subsequent contact and fusion between the shelves suggests it may be a prerequisite for normal palatal fusion and may represent an expression of the acquisition of a potential to fuse similar to that proposed for palatal fusion in vitro.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091760311
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