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  • 1
    ISSN: 1432-0878
    Keywords: Sensilla ; Olfaction ; Dictyoptera (insect) ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les organes sensoriels du scape et du pédicelle sont essentiellement propriocepteurs. Le fouet est très riche en chimiorécepteurs (plus de 100000) mais chez Periplaneta et Blatta, on observe un net dimorphisme sexuel qui n'existe pas chez Blaberus. La relation entre un tel dimorphisme et la perception des phéromones sexuelles est discutée. L'ultrastructure des trois principaux types de sensilles est décrite: Ce sont des grandes soies gustatives et mécanoréceptrices, des petites soies olfactives à paroi mince et percée de pores et de tubules qui sont innervées par un ou deux neurones, des petites soies olfactives à paroi épaisse et striée qui contiennent toujours quatre neurones. L'étude électrophysiologique préliminaire confirme les résultats ci dessus en ce qui concerne le rôle des sensilles: La phéromone grégaire peut être perçue au niveau de certaines petites soies olfactives striées.
    Notes: Summary The antennae of cockroaches were studied with both scanning and transmission electron microscope. The sense organs of the scape and pedicel are essentially proprioceptors. The chemoreceptors are very numerous on the flagellum (more than 100000) but in the case of Periplaneta and Blatta, a significant sexuel dimorphism is noticed. Such a dimorphism does not exist in Blaberus and its relation with the perception of the sexual attractants is discussed. Three principal sense organs of Blaberus are described: big thick walled hairs with gustatory and mechanoreceptive function; thin walled olfactory hairs with pore-tubules innervated by one or two neurons; thick walled grooved hairs with four neurons and olfactory function. Special attention was given to the secretory aspect of the accessory cells in the olfactory sensilla. A preliminary electrophysiological investigation confirms the above mentioned functional interpretations. The gregarious pheromone seems to be perceived by some little thick walled grooved hairs.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 143 (1973), S. 367-385 
    ISSN: 1432-0878
    Keywords: Pineal ; Hedgehog ; Sexual cycle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les pinéalocytes (au sens strict: Wolfe, 1965) de l'épiphyse du Hérisson mâle, examinés au microscope électronique, ont été comparés à ceux d'autres Mammifères. Ils possèdent un ou plusieurs prolongements cellulaires, dont la terminaison en «massue» est caractéristique. A l'intérieur du noyau, un nucléole de forme alvéolaire facilite l'identification de ce type cellulaire. Dans le périkaryon, des mitochondries, des ribosomes, quelques lysosomes. et inclusions lipidiques sont présents. Des cils et de rares «rubans circonscrits par des vésicules» (Collin, 1969) sont observés. Le réticulum endoplasmique est peu abondant et est constitué, essentiellement, par la forme lisse. L'appareil de Golgi sécrét de petites vésicules claires de 300 à 450 Å de diamètre et des vésicules à coeur dense de 400 à 1500 Å de diamètre. La migration de ces grains vers l'extrémité des prolongements a été mise en évidence. Pendant les phases du cycle sexuel, on observe une évolution de certains éléments des pinéalocytes. D'une part, pendant la phase de mise au repos sexuel, il y a formation, à partir du réticulum, d'un système rectiligne composé de cavités et de vésicules, puis évolution de l'ensemble vers une forme lamellaire concentrique, D'autre part, on note l'apparition de «condensations cytoplasmiques» très importantes durant une partie de la phase de pleine activité sexuelle.
    Notes: Summary The pinealocytes of the male hedgehog have been examined with the electron microscope, and have been compared with those of other mammals. They possess one or more cytoplasmic processes which end in a terminal club. In the nucleus, an alveolar nucleolus facilitates the identification of this cellular type. In the perikaryon, mitochondria, ribosomes, lysosomes and lipid inclusions are present. Cilia and rare “rubans circonscrits par des vésicules” (Collin, 1969) are observed. The endoplasmic reticulum is not very abundant and essentially consists of the smooth type. Small clear vesicles (350–450 Å) and dense-cored vesicles (400–1500 Å) are produced by the Golgi apparatus. The migration of these densecored vesicles towards the terminal processes has been observed. It has been shown that there occurs a change of some cytoplasmic structures during the sexual cycle of this animal. On the one hand, during the period of sexual quiescence, a reticular formation—composed of lamellae and vesicles—is observed in the cytoplasm. This formation is transformed into annular lamellae. On the other hand, during the period of maximal sexual activity, just after the first mating period, numerous “cytoplasmic condensations” are observed.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 46 (1928), S. 453-454 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1573-6709
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Sectorization, which began as “a glorious underground movement,” is now official French policy-and so, inevitably, some of the romance and intense dedication has faded. Despite budget cuts for personnel, programs, and new construction, an administrative structure has been created to provide an adequate standard of community mental health for the French people.
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  • 5
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A variable sensitivity technique using the projection of a fringe pattern is demonstrated for mapping deformations, vibrations, contour lines and differences between two objects. The method does not require laser illumination and gives an opportunity for studying large objects with incoherent light, and is compared with other techniques such as holography or speckle. The limitations likely to be encountered in industrial environments are discussed. The realization and incoherent projection of gratings is also discussed.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Rheologica acta 12 (1973), S. 563-566 
    ISSN: 1435-1528
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Bei der durch Zn(C2H5)2/H2O, Zn(C2H5)2/CH3OH, Al(C2H5)3/H2O und andere Systeme initiierten Polymerisation von N,N-Diäthyl-N-(oxiran-2-ylmethyl)amin (Ia) erhält man nur niedermolekulare polymere in geringer Ausbeute. Das entsprechende Thiiranderivat N,N-diäthyl-N-(thiiran-2-ylmethyl)amin (IIa), gibt mit demselben Initiator Hochpolymere, die nicht kristallin sind, im Gegensatz zu Propylensulfid. Physikalisch-chemische Eigen-schaften (UV-, IR-Spektren, Neutralisation und Gelbindung bei der Neutralisation) wurden untersucht. Höhere Homologe von IIa, die sich von racemischen sec-Aminen R1R2NH ableiten, werden synthetisiert und mit Zn(C2H5)2/H2O polymerisiert. Der Einfluß von R1 und R2 auf die physikalischen und chemischen Eigenschaften der Polymeren wird diskutiert.
    Notes: The polymerization of N,N-diethyl-N-(oxirane-2-ylmethyl)amine (Ia), by initiator systems such as ZnEt2/H2O, ZnEt2/CH3OH, AlEt3/H2O, and others, gives only low molecular weight polymers with low yields. The corresponding thiirane derivative, N,N-diethyl-N-(thiirane-2-yl-methyl)amine (IIa), with the same type of initiators gives high molecular weight polymers which are non-crystalline contrary to the case of propylene sulfide. Physicochemical properties (UV and IR absorptions, neutralization and gelation during neutralization) of these polymers are studied. Higher homologues of IIa derived from racemic secondary amines R1R2NH are synthesized and polymerized with ZnEt2/H2O. The influence of the substitu ents R1 and R2 on the physical and chemical properties of the polymers is discussed.
    Additional Material: 5 Ill.
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  • 9
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Proton-proton 3J, 4J and 5J NMR coupling constants have been calculated for cyclohexane and monosubstituted cyclohexane conformers (substitiuents: Li, CH3, OH, F) by the two methods mentioned. Comparing the two methods on the basis of group theory, we show the necessity to use the second. The results from this method are compared with those of the literature.
    Notes: Les constantes de couplage RMN 3J, 4J et 5J entre protons ont été calculées par les deux méthodes citées, pour le cyclohexane et pour les conformères de ses dérivés monosubstitués (substituants: Li, CH3, OH, F). La comparaison des deux méthodes sur la base de la théorie des groupes met en évidence la nécessité d'utiliser la méthode des perturbations finies dont les résultats sont confrontés avec les données expérimentales de la littérature.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The complex Eu (FOD)3 is shown to be a convenient shift reagent for Δ1-pyrazolines. The five examples described here were chosen to illustrate the usefulness of this method in the attribution of the stereochemistry of polycyclic Δ1-pyrazolines.
    Notes: Le complexe Eu (FOD)3 constitue un bon réactif de déplacement en spectroscopie de RMN de Δ1-pyrazolines. Les 5 exemples décrits ici ont été choisis en série polycyclique pour mettre en évidence l'utilité de cette technique en vue de l'attribution des stéréochimies.
    Additional Material: 2 Tab.
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