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  • 1980-1984  (590)
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  • Cat
  • 1
    Electronic Resource
    Electronic Resource
    Cumulative effect of brief daily periods of monocular vision on kitten striate cortex (1980)
    Springer
    Experimental brain research 38 (1980), S. 53-56 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Monocular deprivation ; Visual cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Eight kittens were subjected to daily 4-h sessions with vision restricted to one eye between the 4th and 9th postnatal weeks. The total duration of monocular exposure ranged from 76 to 152 h. Between monocular exposure periods, four kittens were kept in total darkness, and four experienced binocular vision under normal colony conditions. At the end of the rearing period, all experimental animals and four normally reared controls were studied by means of single-unit recording in primary visual cortex. In kittens with inter-session dark rearing, very few neurons could be driven through the deprived eye. This effect was more extreme than that observed after continuous dark rearing. Visual responses mediated by the experienced eye appeared normal. In contrast, in kittens with inter-session binocular vision, the large majority of visual cortical neurons responded to visual stimulation of either eye. A few neurons appeared to have lost their responsiveness to the deprived eye, but this effect was small. We conclude that monocular vision delivered during brief daily sessions produces a cumulative competitive inactivation of transmission in the pathway from the deprived eye to striate cortex so long as no visual stimulation occurs outside the monocular periods. Binocular visual stimulation received between sessions rapidly and almost completely reverses the effects of monocular vision.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237930
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  • 2
    Electronic Resource
    Electronic Resource
    Development of binaural input, response patterns, and discharge rate in single units of the cat inferior colliculus (1980)
    Springer
    Experimental brain research 38 (1980), S. 103-108 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Auditory ; Binaural ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The binaural input to single neurones in the inferior colliculus of barbiturate- and ketamine-anaesthetised kittens was tested using pure tones. Stimuli were presented to each ear independently via sealed sound-delivery systems. Cells were classified according to the predominant type of input (excitatory or inhibitory) from each ear. There was no significant difference between age groups in the proportions of cells showing each type of binaural input. For all ages, cells excited by monaural stimulation of either ear (EE cells) tended to be of low best frequency (BF) and cells excited by monaural stimulation of one ear, but inhibited by simultaneous stimulation of the other ear (EI cells), had higher BFs. Units for which quantitative spike count data were obtained were also categorised according to their response pattern. Cells categorised as “onset”, “pauser” and “burst-type” were found in approximately equal proportions in animals of all age groups. “Primary-like” units were not found in animals less than 20 days old. Unit discharge rate was significantly higher for adults than for any of the three kitten groups. These data suggest that (1) binaural connections are not subject to postnatal developmental alteration and (2) the development of excitatory responses after 20 days consists of an increase in the number of discharges rather than a change in the pattern of these discharges.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237936
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  • 3
    Electronic Resource
    Electronic Resource
    A direct pathway from thalamus to visual callosal neurons in cat (1980)
    Springer
    Experimental brain research 38 (1980), S. 121-123 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Visual cortex ; Corpus callosum ; Horseradish peroxidase ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Horseradish peroxidase was injected in the right visual cortex and a large electrolytic lesion made in the left lateral geniculate nucleus of an adult cat. Neurons of origin of the callosal projection to the injected cortex were identified by retrograde labelling and selected for electron microscopic study. Degenerating thalamo-cortical axon terminals were found to contact a labelled stellate cell in layer IV and a labelled pyramidal cell in layer III at the border region of areas 17 and 18. We conclude that there is a monosynaptic pathway from lateral geniculate nucleus to the cells of origin of callosal axons to the contralateral visual cortex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237940
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  • 4
    Electronic Resource
    Electronic Resource
    Ultrastructure of degenerating cerebellothalamic terminals in the ventral medial nucleus of the cat (1980)
    Springer
    Experimental brain research 38 (1980), S. 125-135 
    Details
    ISSN: 1432-1106
    Keywords: Ventromedial thalamic nucleus ; Cerebellar degenerating boutons ; Ultrastructure ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Terminal degeneration of cerebellar afferents in the ventral medial thalamic nucleus (VM) was studied in cats at the ultrastructural level after uni- or bilateral lesions in the brachium conjunctivum (BC). To achieve discrete lesions within the BC, a new very accurate stereotaxic technique was used. Numerous large terminals belonging to a population of so-called LR boutons were observed degenerating in the VM. The boutons displayed a wide variety of degenerative changes. Some revealed the features of the classical neurofilamentous type of degeneration. Others, although containing a slightly increased number of neurofilaments, featured much more prominently large numbers of coated vesicle shells and heavy accumulations of a flocculent electrondense material. Degeneration in a third group of boutons similar to some extent to the light type of degeneration was characterized by tight clumping of enormously swollen or distorted synaptic vesicles within a light matrix. At later stages, however, all these boutons were believed to become shrunken and electron-dense since intermediate stages between the light- and dark-appearing boutons were observed. The degenerating cerebellar boutons formed asymmetrical synaptic contacts. Groups of 3 or 4 boutons terminated upon dendrites of projection neurons synapsing more frequently on spines than on dendritic stems. The synaptic contacts between cerebellar boutons and the vesicle-containing dendrites of local circuit neurons were encountered as often if not more than the contacts on projection neuron dendrites. Triads consisting of cerebellar boutons and dendrites of both types of neurons were observed very regularly. This synaptic arrangement provides the anatomical basis for the modification of cerebellar input in the VM by interneurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236734
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  • 5
    Electronic Resource
    Electronic Resource
    Stimulation of the superior colliculus in the alert cat (1980)
    Springer
    Experimental brain research 39 (1980), S. 63-73 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Stimulation ; Superior colliculus ; Eye movements ; Eye-head coordination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electrical stimulation of the cat superior colliculus (SC), in conjunction with the accurate measurement of elicited eye movements and histologically verified electrode positions, has revealed a striking antero-posterior variation in collicular organization. Three zones could be defined in the SC on the basis of eye movement patterns and associated neck muscle EMG activity evoked from the deeper layers. The Anterior zone was coextensive with the central 25 ° of the visual retinotopically coded map contained in the superficial layers. Saccades evoked from this zone were also retinotopically coded, and the latency of EMG activity depended on the position of the eye in the orbit. A similar observation applies to the entire monkey SC. The Intermediate zone was coextensive with the 25 °–70 ° of visual projections. Saccades evoked from this region were “goal-directed” and were associated with invariant, short latency EMG responses. The Posterior zone was found in the extreme caudo-lateral portion of the SC. Eye movements evoked from this zone were centering saccades associated with constant latency EMG activity. The present results in conjunction with previously demonstrated antero-posterior variations in projections to the SC, suggest that the motor strategies controlling gaze shifts toward visual targets vary depending on the location of the target in the visual field.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237070
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  • 6
    Electronic Resource
    Electronic Resource
    Prefrontal cortex of the cat: Paucity of afferent projections from the parietal cortex (1980)
    Springer
    Experimental brain research 39 (1980), S. 105-112 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Prefrontal cortex ; Parietal cortex ; Mediodorsal thalamic nucleus ; Horseradish peroxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twenty-one cat brains with cortical injections of horseradish peroxidase resulting in labelled cells in the thalamic mediodorsal nucleus (MD) were screened for afferent projections from the parietal cortex. Contrary to expectation, nearly the whole prefrontal cortex (PFC) situated around the frontal pole was free of parietal afferents, while a small area in the anterior sylvian gyrus (orbito-insular subregion of PFC) consistently received afferents from the parietal cortex. The few afferents projecting to the cortex around the frontal pole originated exclusively from the convexity of the suprasylvian gyrus, while the great majority of the parietal neurons projecting to the anterior sylvian gyrus was situated within the fundus of the suprasylvian sulcus. While the main regions of the prefrontal cortex of the rhesus monkey receive a substantial projection from the parietal lobe, whereas the main regions of the cat's prefrontal cortex are free of afferents from the parietal cortex, possible differences in the parieto-prefrontal organization of both species are discussed. Furthermore, differences between the orbito-insular subregion and the rest of the PFC are emphasized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237073
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  • 7
    Electronic Resource
    Electronic Resource
    Rarity of luxotonic responses in cortical visual areas of the cat (1980)
    Springer
    Experimental brain research 39 (1980), S. 125-132 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Visual cortex ; Luxotonic sustained responses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neuronal responses to continuous, diffuse white light or darkness were studied in cortical visual areas 17, 18, 19 and Clare-Bishop of the unanesthetized cat. In contrast to squirrel monkeys and macaques in which about 40 or 25% of the units in striate cortex are luxotonic (response to continuous light or darkness sustained〉2.0 min), all of the visual areas in the cat had fewer than 4.0% of the units exhibiting such luxotonic activity. The functional basis of this difference may be related to differences between the two species in the quantitative balance of antagonistic receptive field properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237544
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  • 8
    Electronic Resource
    Electronic Resource
    Low threshold afferent projections from the oral cavity and the face to the cerebral cortex of the cat (1980)
    Springer
    Experimental brain research 39 (1980), S. 133-147 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Somatosensory cortex ; Oral projections ; Face projections ; Cytoarchitectonic organization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The projections of low threshold afferents from the oral cavity and the face to the cerebral cortex of cats anaesthetized with chloralose were investigated. The projection fields of the ipsi- and contralateral lingual, inferior alveolar, mental, superior alveolar, infraorbital, (separate branches from whiskers and nose), ophthalmic, great auricular and the contralateral superficial radial nerves were localized. Surface potentials of short latency and maximal amplitude were recorded and their location traced on photographs of the rostral part of the right cerebral hemisphere. Reference points were indicated with india ink punctures. The extent of the cytoarchitectonic areas was determined on histological serial sections and the borders transferred to the photographs of the hemisphere. The features of the projections were related to the cytoarchitecture and to the pattern of the gyri and sulci. It was observed that the low threshold afferents from the oral cavity and the face projected via fast conducting, presumably three synaptic paths, to separate locations in areas 3a, 3b, 5a and 6aβ. The projections to area 3b were somatotopically organized starting with the auricular and the ophthalmic nerve projections lateral to the 3b projection of the forelimb in the posterior sigmoid gyrus and continuing with the maxillary nose, maxillary whiskers, mental nerve, superior alveolar, inferior alveolar and lingual nerve fields along the coronal gyrus towards the presylvian sulcus. The somatotopy was, however, not isomorphic with the body surface but displayed consecutive, overlapping bands across area 3b. The projections to area 3a were similarly organized. The somatotopy was less obvious in area 5a and 6aβ. Convergent projections with responses of slightly longer latency were observed in area 43 (gyrus orbitalis).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237545
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  • 9
    Electronic Resource
    Electronic Resource
    The effect of electrical stimulation in the hypothalamus on the monosynaptic jaw closing and the disynaptic jaw opening reflexes in the cat (1980)
    Springer
    Experimental brain research 39 (1980), S. 389-400 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Jaw reflexes ; Hypothalamus ; Aggression ; Bruxisrn
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of electrical stimulation in the hypothalamus on the monosynaptic jaw closing and the disynaptic jaw opening reflexes were investigated in cats anaesthetized with chloralose. The hypothalamic electrodes were located by observation of behavioural attack responses in the unanaesthetized animal and by means of Horsley-Clarke coordinates. The locations were verified in histological serial sections. Hypothalamic conditioning with trains of 3–10 pulses, 0.5 ms duration, 0.5 mA, 500 Hz, evoked a strong facilitation of the jaw closing reflex and a facilitation followed by an inhibition of the jaw opening reflex. These effects differed from those elicited from the cerebral cortex. The hypothalamic effects had a longer latency (11–13 ms) and required a longer train of conditioning stimuli than was the case with those evoked from the cortex. Bilateral ablation of the sensorimotor cerebral cortex or lesion of the pyramids at the lower pontine level diminished but did not abolish the hypothalamic effects. They did, however, disappear after lesions including the ventral midbrain tegmentum. The stimulus positions eliciting the largest hypothalamic effects on the jaw reflexes were located in a region extending medio-laterally from the perifornical area to the entrance of the ansa lenticularis in the lateral hypothalamus. Rostro-caudally the location was found at the level of the ventromedial hypothalamic nucleus and the anterior hypothalamus just rostral to this nucleus. The region corresponds to those parts of the hypothalamus from which agonistic and feeding responses have been evoked. It is suggested that the observed hypothalamotrigeminal mechanism may exercise a tonic influence on the trigeminal motoneurones, thereby controlling the set point of the biting force. The implications of this hypothesis on the etiology of bruxism and the myofascial pain dysfunction are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239303
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  • 10
    Electronic Resource
    Electronic Resource
    Functional amblyopia in kittens with unilateral exotropia (1980)
    Springer
    Experimental brain research 40 (1980), S. 294-304 
    Details
    ISSN: 1432-1106
    Keywords: Squint amblyopia ; Visual cortex ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In two cats in which surgically induced, unilateral divergent strabismus had led to behaviourally determined amblyopia, a variety of electrophysiological parameters were determined in search of neuronal correlates of squint amblyopia. Tests that assess global neuronal excitability along the pathways from the two eyes to the visual cortex (areas 17 and 18) failed to reflect the functional inferiority of the squinting eye: retinographic responses and cortical evoked potentials elicited by Ganzfeld-stimulation and by stimulation of the optic nerves were identical for the two eyes. The ocular dominance distribution of neurons in area 17 showed the expected disruption of binocularity but failed to provide clear evidence for a functional inferiority of the squinting eye. At other levels of analysis, however, a clear difference between the two eyes was apparent: 1. Responses to optimally aligned light stimuli tended to be more sluggish and the under-representation of neurons with vertically oriented receptive fields was more pronounced in neurons driven from the deviated eye than in cells dominated by the normal one. 2. Interocular inhibition as assessed from electrically evoked potentials was found to be asymmetric; responses evoked from the amblyopic eye were suppressed more readily and over longer periods by conditioning shocks applied to the normal nerve than vice versa. 3. Numerous abnormalities reflecting the functional inferiority of the squinting eye became apparent in cortical potentials evoked by phase reversal of gratings of variable spatial frequency and contrast. A laminar analysis of these field potentials suggests impaired transmission along the intracortical pathways which relay activity to supragranular layers as a major cause for abnormal responses from the squinting eye. It is concluded that squint amblyopia is associated with a variety of neuronal changes at various levels of the visual system, the present data providing evidence for alterations at the cortical level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237794
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  • 11
    Electronic Resource
    Electronic Resource
    Effect of amphetamine and pentobarbital on sleep-wake patterns of cats with basal forebrain lesions (1980)
    Springer
    Psychopharmacology 68 (1980), S. 179-184 
    Details
    ISSN: 1432-2072
    Keywords: Amphetamine ; Pentobarbital ; Sleepwake ; EEG ; REM sleep ; Forebrain ; Cat ; Lesion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of amphetamine and pentobarbital upon electrographic state were studied in naive cats and cats with forebrain lesions that induce insomnia. Amphetamine increased alertness and decreased both slow wave sleep (SWS) and rapid eye movement (REM) sleep states for up to 12 h in both intact animals and cats with lesions. Pentobarbital inhibited REM sleep and alert states while increasing SWS and drowsy states in naive cats. The effect was mainly restricted to the first 8 h. In cats with forebrain lesions, the effects were similar except that the amount of REM sleep was significantly elevated. During a portion of the first 8 h, the tracing cannot be distinguished from a normal control sample. It is hypothesized that pentobarbital mimics the normal inhibitory influence of the intact forebrain and either induces or facilitates ‘normal’ sleep patterns in cats with forebrain lesions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432138
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  • 12
    Electronic Resource
    Electronic Resource
    The tapetal cell: A unique melanocyte in the tapetum lucidum cellulosum of the cat (Felis domestica L.) (1980)
    Springer
    Anatomy and embryology 158 (1980), S. 289-302 
    Details
    ISSN: 1432-0568
    Keywords: Tapetum lucidum ; Cat ; Melanocytes ; Development ; DOPA-reaction ; DOPA ; cysteinyldopa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The postnatal development of the tapetum lucidum cellulosum of the cat was studied with cytochemical, histochemical, microspectrofluorimetric, and chemical methods. At birth, the prospective tapetal cells exhibit a cytoplasmic, formaldehyde-induced catechol fluorescence which, by spectrographical criteria, is due to the presence of a thioether of DOPA, most likely 5-S-cysteinyldopa. These cells show a positive DOPA-reaction in the GERL, a Golgi-associated system of smooth endoplasmic reticulum. Beyond the third postnatal week, tyrosinase activity is found in the GERL and in the premelanosomal-like tapetal rods. Shortly thereafter, cells in the innermost layers of the tapetum reveal a change in the colour of the fluorophore from green (formaldehyde-induced) to orange-yellow (autofluorescent). Concomitant with the appearance of the yellow fluorophore (having spectral characteristics similar to authentic riboflavin), the DOPA-reactivity in the tapetal cells is no longer detectable and the cells attain the feature of mature tapetal elements with typical elongated, parallelly arranged, electron-dense rods. The increases and decreases in tyrosinase activity are parallelled by similar time-dependent changes in DOPA and cysteinyldopa content. Both DOPA and cysteinyldopa are considered as potential precursors of melanin polymers. Thus, these data support the concept that the tapetal cells represent uniquely differentiated and highly specialized choroidal melanocytes. The compact arrangement of these cells in the tapetum lucidum renders it an ideal tissue for studying the developmental biology of melanocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00301818
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  • 13
    Electronic Resource
    Electronic Resource
    The reticulocerebellar projection in the cat as studied with retrograde transport of horseradish peroxidase (1980)
    Springer
    Anatomy and embryology 160 (1980), S. 341-359 
    Details
    ISSN: 1432-0568
    Keywords: Reticulocerebellar ; Peroxidase ; Retrograde transport ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Injections of horseradish peroxidase into the various parts of the cerebellar cortex and the cerebellar nuclei in the cat result in labelled cells within the reticular formation proper. All the reticular nuclei (with the exception of the reticular formation of the mesencephalon) send fibres to the cerebellum. The highest number of labelled neurons after cerebellar injections is found in the caudal reticular formation, especially within nucleus reticularis ventralis, nucleus reticularis lateralis and nucleus reticularis gigantocellularis. Another region for an accumulation of labelled cells is the rostral part of nucleus reticularis pontis caudalis. Except for the paraflocculus, all cerebellar cortical areas and all cerebellar nuclei receive afferents from one or more of the nuclei within the reticular formation proper, but the largest number of labelled neurons is observed in cases with injections including the intermediate-lateral part of lobulus simplex and the adjacent areas of the anterior lobe and crus I. The projection is bilateral with an ipsilateral preponderance (the cerebellar nuclei appear to receive a higher number of fibres from the contralateral side). Cells of all sizes are labelled, but labelled giant cells are found only after large cortical injections.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305113
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  • 14
    Electronic Resource
    Electronic Resource
    Mapping of monoamine neurones and fibres in the cat lower brainstem and spinal cord (1980)
    Springer
    Anatomy and embryology 161 (1980), S. 169-195 
    Details
    ISSN: 1432-0568
    Keywords: Monoamines ; Histofluorescence ; Brainstem ; Spinal cord ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The localization of monoaminergic neurones in the medulla oblongata and the pons, and the distribution of catecholaminergic fibres in the spinal cord of the cat were investigated by means of formaldehyde-induced (FIF) or glyoxylic-acid-induced (GIF) fluorescence. Four groups of catecholamine (CA)-containing neurones were found in the following regions: (1) in the ventrolateral medulla oblongata within and adjacent to the lateral reticular nucleus, beginning slightly rostral to the medullo-spinal junction and extending rostrally to the cranial third of the inferior olive; (2) in the commissural, medial and lateral nucleus of the solitary tract; (3) cranial to the first group, closely adjacent to the facial nucleus and the superior olive; and (4) in the dorsolateral pons distributed to different nuclei, namely the nucleus coeruleus and subcoeruleus, the Koelliker-Fuse nucleus, and the medial and lateral parabrachial nuclei. The indoleamine (IA)-containing cell bodies were in general confined to the raphe nuclei, namely the nucleus raphe pallidus, nucleus raphe obscurus, nucleus raphe magnus, nucleus raphe pontis, nucleus raphe dorsalis and the central superior nucleus. A few IA-neurones were located more laterally, especially dorsal and lateral of the cranial half of the inferior olive, around the root of the hypoglossal nerve, in the lateral tegmental field and the pontine central gray. In the spinal cord most CA-fibres were found in the intermediolateral cell column. Another dense accumulation of CA-fibres was located dorsally and laterally of the central canal. The ventral and dorsal horns also contained CA-nervefibres which were slightly more numerous in the sacral spinal cord than in the more rostral parts of the spinal cord.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305343
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  • 15
    Electronic Resource
    Electronic Resource
    The cat locus coeruleus (1980)
    Springer
    Anatomy and embryology 159 (1980), S. 181-198 
    Details
    ISSN: 1432-0568
    Keywords: Cat ; Locus coeruleus ; Neuroanatomy ; Cytology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The neuronal cell bodies of the locus coeruleus (LC) and subcoeruleus (SC) of the cat were investigated using Nissl and Golgi preparations, and electron microscopy. On the basis of morphological criteria — size and shape of cell body, branching pattern of dentrites, distribution of cytoplasmic organelles and number of axosomatic synapses — four types of neuronal perikarya were recognized in each region: medium-sized, small-sized and two groups of intermediate-sized neurons. The medium-sized neurons (30–50 μm) had an elongated cell body, thick dendrites with a moderate number of branchings, abundant organelles arranged in concentric rings around the nucleus and a moderate number of axosomatic synapses. They were found throughout the LC and SC and most probably correspond to the larger class of catecholaminergic neurons demonstrated by fluorescence histochemistry. The small neurons (10–25 μm) were also seen in both LC and SC and are believed to represent non-monoaminergic local interneurons. They displayed sparsely branching dendrites and a thin rim of cytoplasm containing few organelles. In the SC, some of these small cells occurred in closely associated pairs. Ultrastructural analysis of such pairs revealed a close apposition (80–100 Å) of the cell membranes for long distances (up to 10 μm) and a narrowing of the intercellular space (30–40 Å) at some discrete points, perhaps indicative of an electrical interaction. The intermediate-sized neurons exhibited some regional morphological differences, but two distinct subgroups could be distinguished. One was characterized by a low number of axosomatic synapses, while the other exhibited a high number of such contacts. It may be assumed that the two subgroups of intermediate-sized neurons comprise catecholaminergic and indolaminergic neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00304977
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  • 16
    Electronic Resource
    Electronic Resource
    Profile of the sensitive period for monocular deprivation in kittens (1980)
    Springer
    Experimental brain research 39 (1980), S. 17-21 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Monocular deprivation ; Visual cortex ; Sensitive period
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thirteen kittens were subjected to 10–12 days of unilateral eye closure at ages spaced regularly through the first 4 months after birth. At the end of each kitten's period of monocular vision, the degree of functional disconnection between the deprived eye and neurons in striate cortex was assessed by means of single-unit recording. When the proportion of cortical cells giving no response to stimulation through the deprived eye was analyzed as a function of the kitten's age at the onset of eye closure, it was found that the effectiveness of monocular deprivation rose prior to postnatal day 28, remained high through day 48 and then subsided gradually, probably persisting at least through the end of the fourth postnatal month. The degree of functional modifiability persisting in the visual cortex of older kittens may be related to the initial ocular dominance of each neuron. Cells responsive exclusively to the deprived eye prior to deprivation probably do not acquire functional input from the nondeprived eye in kittens older than 48 days, for a normal proportion of such cells is encountered after the period of eye closure. Conversely, cells dominated by the nondeprived eye probably are most likely to lose their input from the deprived eye, as indicated by the columnar organization of cells not responsive to the deprived eye.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237065
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  • 17
    Electronic Resource
    Electronic Resource
    Functional changes across the 17–18 border in the cat (1980)
    Springer
    Experimental brain research 39 (1980), S. 177-186 
    Details
    ISSN: 1432-1106
    Keywords: Visual cortex ; Cat ; Areas 17 and 18 ; Velocity sensitivity ; Magnification factor ; Vertical meridian
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Changes in velocity sensitivity, receptive field (RF) position, and RF size were investigated in long oblique penetrations crossing the 17–18 border. The penetrations were histologically reconstructed and the border determined by cytoarchitectonics. In cortex subserving central and paracentral vision change in velocity sensitivity allowed a reasonable physiological identification of the 17–18 border. The physiological border correlates well with the histological border zone, best with its medial edge. Changes in RF position and RF size are of little use for physiological identification of the border in this region. In this cortical region area 18 representation of the vertical meridian (VM) has a high magnification factor. In cortex subserving peripheral vision, the change in velocity sensitivity was small and the change in RF position coincided with the cytoarchitectonics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237548
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  • 18
    Electronic Resource
    Electronic Resource
    Facilitation and inhibition of jaw reflexes evoked by electrical stimulation of the cat's cerebral cortex (1980)
    Springer
    Experimental brain research 39 (1980), S. 149-164 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Jaw reflexes ; Cerebral cortex ; Cytoarchitectonic areas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of electrical stimulation of the cerebral cortex on the monosynaptic jaw closing and the disynaptic jaw opening reflexes were studied in cats anaesthetized with chloralose. The time course of the reflex effects was recorded. Similar rhythmic sequences of facilitation and inhibition were observed in both reflexes (Fig. 3). The sequence could start with facilitation or inhibition. The latency of the initial effects was short (2.5 ms) indicating a minimum of two synapses in the descending path. The period of the rhythmic sequence was approximately 10 ms. Optimal parameters for the conditioning cortical stimuli were found to be: trains of 3–5 surface anodal pulses, 0.5 ms, 400 Hz. The threshold of the cortical effects on the reflexes was 0.3 mA. A single pulse evoked effects. The cortical origin of the effects was located and related to the somatosensory projections, and to the cytoarchitecture. The effects of largest amplitude and most complex time course were evoked from the oral and perioral projections to areas 3a and 3b. Effects evoked from areas 4γ, 5a, and 6aβ were less complex and of lower amplitude. It is suggested that a trigemino-cortico-trigeminal loop via 3a may function in reflex modulation of the jaw movements. In addition area 3a may contribute to cortico-cortical motor elaborations via U-fiber connections to area 4γ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237546
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  • 19
    Electronic Resource
    Electronic Resource
    Mécanorécepteurs splanchniques de la voie biliaire et de son péritoine (1980)
    Springer
    Experimental brain research 40 (1980), S. 146-153 
    Details
    ISSN: 1432-1106
    Keywords: Microelectrode technique ; Splanchnic mechanoreceptors ; Gall bladder ; Cat ; Microélectrode mecanarecepteurs splanchniques ; Vesicule biliaire ; Chat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Le but de ce travail est l'étude électrophysiologique des mécanorécepteurs de la vésicule biliaire. L'activité unitaire des neurones est enregistrée au moyen de microélectrodes de verre extracellulaires implantées dans les ganglions spinaux (T6-L1). Deux types de mécanorécepteurs ont été mis en évidence par stimulation punctiforme. Mécanorécepteurs musculaires a) Des récepteurs à adaptation lente localisés dans l'ensemble du tractus biliaire, sensibles à la distension. b) Des récepteurs à adaptation rapide, localisés dans la vésicule biliaire, mis en jeu par la phase dynamique de la stimulation. Ces récepteurs sont connectés avec des fibres C. Mécanorécepteurs péritonéaux a) Des corpuscules de Pacini, localisés dans le mésentère entourant le tractus biliaire. b) Des récepteurs à adaptation lente (récepteurs de mouvement), localisés dans la séreuse de la vésicule biliaire et le péritoine péricystique et péricholédocien. Les corpuscules de Pacini sont connectés avec des fibres Aβ, les récepteurs de mouvement avec des fibres Aγδ et B.
    Notes: Summary The aim of the present paper is to study the electrophysiology of splanchnic gall bladder mechanoreceptors. The neurons unitary activity is recorded by means of glass extracellular microelectrodes implanted in the spinal ganglion (T6-L1). Two types of mechanoreceptors have been revealed by punctiform stimulations. Muscular Mechanoreceptors a) Slowly-adapting receptors, located in the whole biliary tract, sensitive to distension. b) Rapidly-adapting receptors, located in the gall bladder, recruited during the dynamic phases of stimulation. These receptors connected with C fibers. Peritoneal Mechanoreceptors a) Pacinian corpuscles, located in the mesentery surrounding the biliary tract. b) Slowly-adapting receptors (movement receptors), located in the serosa of the gall bladder and the pericystic and pericholedochal peritoneum. Pacinian corpuscles are connected with Aβ fibers, movement receptors with Aγδ and B fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237532
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  • 20
    Electronic Resource
    Electronic Resource
    Organization of the cortico-caudate projections (1980)
    Springer
    Experimental brain research 40 (1980), S. 203-208 
    Details
    ISSN: 1432-1106
    Keywords: Cortico-caudate neurones ; Premotor area ; Horseradish peroxidase ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The organization of the cortico-caudate projection neurones in the cerebral cortex was demonstrated by utilizing retrograde axonal transport of horseradish peroxidase (HRP) in the cat. Following injection of HRP into the head portion of the caudate nucleus, cortical labelled cells with HRP could be divided into two groups, consisting of smaller and larger pyramidal neurones. The location of the smaller neurones in the cortex was mainly in layer III, while that of the larger neurones was exclusively in layer V. In the cerebral cortex ipsilateral to the HRP-injected side, labelled cells belonging to the smaller group were distributed mostly in area 6 and occasionally in areas 4 and 5. Labelled cells belonging to the larger group were located exclusively in area 6. In the contralateral cortex, labelled cells were all smaller in size and distributed only in area 6. Referring to recent physiological as well as anatomical data, the smaller, labelled pyramidal cells were considered to be the proper, direct cortico-caudate neurones. The larger, labelled pyramidal cells were regarded as cortico-caudate projection neurones also sending axons to the lower brains tern and/or the spinal cord. The results of the present study indicate the existence of a close relationship between area 6 (premotor area) of the cerebral cortex and the caudate nucleus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237538
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  • 21
    Electronic Resource
    Electronic Resource
    Brain stem projections to the pulvinar-lateralis posterior complex of the cat (1980)
    Springer
    Experimental brain research 40 (1980), S. 209-220 
    Details
    ISSN: 1432-1106
    Keywords: Thalamus ; Visual system ; HRP ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present experiments were undertaken to define the areas of projection of pretectum and superior colliculus to the pulvinar and n. lateralis posterior, respectively, and to define other brain stem structures projecting to these thalamic nuclei in cats. For this purpose the technique of retrograde transport of horseradish peroxidase (HRP) has been used. After injection of the enzyme in the pulvinar, neurons were labeled in all subdivisions of the pretectal area. The majority of the labeled cells were located in the n. pretectalis posterior and n. tractus opticus although cells filled with HRP were present also in the n. pretectalis anterior pars compacta and area pretectalis medialis. Neurons projecting to the pulvinar were also found in the periaqueductal gray, reticular formation and locus coeruleus. When HRP was injected in the n. lateralis posterior, labeled neurons were present in the II and III subdivisions of the second layer of the superior colliculus. The location of these cells shifted from medial to lateral as the injections were shifted from posterior to anterior within the lateralis posterior. Neurons projecting to this nucleus were also present in the intermediate layers of the superior colliculus, lateral hypothalamus and parabigeminal nucleus. The possible role of the pretectal area and superior colliculus in mediating somesthetic input to the pulvinar and lateralis posterior, respectively, and the role of these structures in the control of ocular movements, are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237539
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  • 22
    Electronic Resource
    Electronic Resource
    Cells of origin of crossed and uncrossed corticospinal fibers in the cat (1980)
    Springer
    Experimental brain research 40 (1980), S. 23-34 
    Details
    ISSN: 1432-1106
    Keywords: Pyramidal tract ; MI ; SI ; SII ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cortical distribution of the cells of origin of the dorsolateral and the ventral corticospinal tracts was studied in cat. This was done by making subtotal spinal transections, which in different experiments spared different portions of one ventral or one lateral funiculus at C5–C7. One week later horseradish peroxidase (HRP) injections were made one segment caudal to the lesion and the cortical distribution of the HRP labeled neurons was studied. Thus, it was found that the dorsolateral corticospinal tract at C5–C7 is composed of crossed and uncrossed fibers in a ratio of about 10 ∶ 1, while the ventral corticospinal tract, which contains much fewer cortical fibers, is composed of crossed and uncrossed fibers in a ratio of approximately 1 ∶ 1. Further, the primary motor cortex (area 4) was found to contribute fibers to both the crossed and the uncrossed dorsolateral corticospinal tract as well as to both the crossed and the uncrossed ventral corticospinal tract. The primary somatosensory cortex (area 3a, 3b, 1–2, 5a, 5b) as well as the secondary somatosensory cortex (area 2 pre-insularis), on the other hand, were found to contribute fibers mainly to the crossed dorsolateral tract. Area 4 was found to display a further organization, such that it contains a medial and a lateral part, both of which contribute mainly fibers to the crossed dorsolateral tract, while the remainder of area 4 contributes fibers to the crossed and uncrossed dorsolateral as well as to the crossed and uncrossed ventral tracts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236659
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  • 23
    Electronic Resource
    Electronic Resource
    Functional amblyopia in kittens with unilateral exotropia (1980)
    Springer
    Experimental brain research 40 (1980), S. 305-310 
    Details
    ISSN: 1432-1106
    Keywords: Squint amblyopia ; Visual cortex ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In two dark reared, 40 day old kittens unilateral divergent squint was induced be resecting the insertion of the medial rectus muscle. Behavioural testing revealed that the kittens used only the normal eye for fixation. Contrast sensitivity functions of the two eyes and visual acuity were determined behaviourally in a jumping stand whereby the kittens had to discriminate sine-wave gratings or variable spatial frequency and contrast from a flux equated homogeneous field. At photopic luminance levels the deviated eye showed a significant deficit in both kittens. This impairment was apparent over the whole range of spatial frequencies (0.18–0.99 c/deg) except for the lowest spatial frequency in one kitten. The interocular difference of visual acuity disappeared at scotopic luminance levels. In subsequent electrophysiological experiments contrast sensitivity functions were determined from cortical evoked potentials that were elicited by phase reversing square wave gratings. Comparison between behavioural and electrophysiological results revealed a very good correspondence between the two sets of data. It is concluded that exotropia without alternating fixation leads to functional amblyopia of the deviated eye.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237795
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  • 24
    Electronic Resource
    Electronic Resource
    Physiological responses of cat vestibular nerve to a selective mechanical stimulation of the lateral crista ampullaris (1980)
    Springer
    Experimental brain research 40 (1980), S. 358-360 
    Details
    ISSN: 1432-1106
    Keywords: Mechanical stimulation ; Cristae ampullares ; Vestibular ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present report describes a bidirectional mechanical stimulation technique of cristae ampullares in the cat. Bimodal field potentials are seen in the vestibular nerve and nucleus after an excitatory stimulus. This technique should allow an in vivo and selective study of the vestibular receptors in mammals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237804
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  • 25
    Electronic Resource
    Electronic Resource
    A statistical analysis and comparison of soma diameter spectra for classical neurones from different regions of the cat retinal ganglion cell layer (1980)
    Springer
    Pflügers Archiv 388 (1980), S. 239-242 
    Details
    ISSN: 1432-2013
    Keywords: Statistical model ; Cat ; Retina ; Ganglion cell layer ; Neuronal diameter spectra
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Multimodal soma diameter spectra for neurones of the cat retinal ganglion cell layer have been represented by three subpopulations of independent, normal diameter distribution. Recurrent computation according to the technique of Vibert and Caille (1978) has extracted best fit populations for samples from various regions of central and peripheral retina. The model subpopulations from all these regions did not differ significantly in their relative proportions or variance. Significant progressive variation between subpopulations representing different regions of retina were observed only in the mean diameter of the α and β mode cells. The parameters of the γ mode population were statistically uniform across the retina. The cat retina thus appears to be more homogeneously organized than has been suggested elsewhere.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00658488
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  • 26
    Electronic Resource
    Electronic Resource
    The effects of phenylmethanesulfonyl fluoride on delayed organophosphorus neuropathy (1980)
    Springer
    Archives of toxicology 46 (1980), S. 305-311 
    Details
    ISSN: 1432-0738
    Keywords: Cat ; Neurotoxic esterase ; Diisopropylfluorophosphate ; Phenylmethanesulfonyl fluoride ; Neuropathy ; Prevention
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A delayed localized neuropathy of peripheral nerves in a single hind leg of the cat develops after a single intraarterial 2 mg/kg injection of diisopropylfluorophosphate (DFP). This neuropathy is manifested by a maximum loss of the capacity of soleus α-motor nerve terminals to generate stimulus-bound repetition 21 days after DFP exposure. Phenylmethanesulfonyl fluoride (PMSF) is a protective inhibitor of the neurotoxic esterase which is associated with the development of the delayed organophosphorus neuropathy. Pretreatment of cats with PMSF (30 mg/kg i.p.) 24 h before the DFP injection protected the cats from the delayed neuropathy. No clinical neurotoxic signs were observed at 21 days after DFP. The stimulus-bound repetitive capacity of soleus α-motor nerve terminals was not lost at this time and its incidence was much greater than that which occurred in cats not pretreated with PMSF.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00310448
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  • 27
    Electronic Resource
    Electronic Resource
    Veränderungen im Sehsystem der Katze nach Netzhautläsionen (1980)
    Springer
    European archives of psychiatry and clinical neuroscience 228 (1980), S. 117-133 
    Details
    ISSN: 1433-8491
    Keywords: Afferent visual system ; Retinal lesions ; Functional neuroplasticity ; Cat ; Afferentes Sehsystem ; Netzhautläsionen ; Funktionelle Neuroplastizität ; Katze
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei erwachsenen Katzen wurden Schichten des Corpus geniculatum laterale (CGL) vollständig oder teilweise durch monoculäre, genau definierte Photokoagulatorläsionen der Netzhaut deafferentiert. Mit Mikroelektroden wurden Einzelneurone aus einer experimentell veränderten Schicht mit Kontrollneuronen aus einer normalinnervierten Schicht des CGL eines Versuchstieres verglichen. Nach Unterbrechung aller Afferenzen eines Auges durch Photokoagulation stieg die anfangs stark verringerte Spontanaktivität in der deafferentierten Schicht an, ohne normale Entladungsraten innerhalb von 10 Wochen wieder zu erreichen. Das Muster von Erregung und Hemmung nach Lichtreizung des nicht-dominanten, gesunden Auges hatte sich zu dieser Zeit völlig verändert. Bei begrenzten, nasalen Netzhautläsionen fanden sich beginnend etwa 27 Tage nach der Koagulation in den Randbezirken der partiellen, visuellen Deafferentierung lichterregbare Zellen mit verschobenen rezeptiven Feldern, denen eine läsionsinduzierte Erregungsausbreitung um maximal 200 μm im CGL zugrunde lag. Kleine, runde Netzhautläsionen bedingten anfänglich eine vollständige, visuelle Deafferentierung eines bestimmten CGL-Bezirks. Nach 30 und mehr Tagen wurde visuelle Erregung aus der normal innervierten Umgebung an Zellen gefunden, die in den ersten Tagen nach der Koagulation unerregbar waren. So wurde bei unveränderter Größe der retinalen Läsion ihre Repräsentation im CGL deutlich verkleinert. Die Befunde weisen im subcorticalen visuellen System der erwachsenen Katze auf läsionsinduzierte Reorganisation hin, die das System zu einer gewissen Kompensation nach Verlust visueller Eingänge befähigen könnte. Eine Übertragbarkeit der Befunde auf die Humanpathophysiologie wird kritisch diskutiert.
    Notes: Summary Layers of the lateral geniculate nucleus (LGN) of mature cats were completely or partially deafferentated by precisely defined photocoagulation of the retina. Single neuron recordings were performed with microelectrodes from an experimentally modified layer and compared with neurons from a normally innervated layer in the same animal. The spontaneous activity of cells after monocular deafferentation was severely reduced in the beginning and increased subsequently without reaching normal values within ten weeks. At this time the pattern of excitation and inhibition after light stimulation of the nondominant unsevered eye had completely changed. Twenty-seven days and later after coagulation of a part of the nasal retina light-excitable cells with displaced receptive fields were found in the LGN in the border region of the partial visual deafferentation. This indicated a lesion-induced lateral expansion of excitation by up to 200 μm within the LGN. Small, round retinal lesions initially caused a complete visual deafferentation of a certain region in the LGN. After 30 days and later visual excitation from the normally innervated surrounding was observed in cells which were not light-excitable during the first days after coagulation. Thus, while the retinal lesion itself did not substantially change, its representation within the LGN was distinctly reduced. The results indicate lesion-induced reorganization in the subcortical visual system of the adult cat. This might enable the system to a certain degree of compensation after loss of visual inputs. The transferability of these results to human pathophysiology has to be critically considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00365600
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  • 28
    Electronic Resource
    Electronic Resource
    Dopamine-induced diuresis in the cat without changes in renal hemodynamics (1980)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 312 (1980), S. 77-83 
    Details
    ISSN: 1432-1912
    Keywords: Dopamine ; Diuresis ; Renal blood flow ; Sympathetic activity ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of intravenous (i.v.) and intraarterial (i.a.) injection and infusion of dopamine (DA) on renal hemodynamics, regional sympathetic activity and kidney function were investigated in anaesthetized cats. In response to the i.v. bolus injection of DA (25 μg/kg), mean arterial blood pressure (MABP) was increased by 19.7%, renal blood flow (RBF) by 16.6%, and regional sympathetic discharges were inhibited. The principal effect of i.a. bolus injection of DA into the renal artery was vasoconstriction. Vasodilation was observed neither after lower doses of DA nor after pretreatment with phenoxybenzamine. During continuous i.v. infusion of 10 μg DA kg−1 min−1 MABP, RBF, renal sympathetic discharges and glomerular filtration rate (GFR) did not change, whereas urine volume was increased by 120.5%, sodium excretion by 99.7%, chloride excretion by 143.2%, and potassium excretion by 31.9%. Urine osmolality was decreased and osmolal clearance increased. Raising the DA dose to 25 μg kg−1 min−1 resulted in a fall of GFR, but the diuretic response was not significantly different from that of the low dose. Bulbocapnine (6 mg/kg i.v.) antagonized the DA-induced diuresis. In conclusion, the diuretic effect of DA in the cat is not dependent on a change in RBF, GFR or renal sympathetic activity. This suggests that a tubular site of action is primarily responsible for DA diuresis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00502578
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  • 29
    Electronic Resource
    Electronic Resource
    Central blood pressure effects of guanylyl-imido-diphosphate and cyclic guanosine-monophosphate (1980)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 312 (1980), S. 31-35 
    Details
    ISSN: 1432-1912
    Keywords: Central blood pressure control ; Cat ; Guanylyl-imido-diphosphate ; Cyclic guanosine monophosphate ; Intracerebroventricular administration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Injections of guanylyl-imido-diphosphate (250, 500 and 1,000 μg/kg) into the lateral cerebral ventricle of the anaesthetized cat induced increases in blood pressure and heart rate while the intravenous injections of the same doses were ineffective, thus indicating a central mechanism of action of this compound which activates adenylcyclase at the catalytic subunit. The results support the hypothesis that the activity of cardiovascular centres depends on the prevailing concentration of cAMP. Intracerebroventricular injection of cGMP (125, 250 and 500 μg/kg) caused hypotension and bradycardia. The effects increased with the dose but were subject to tachyphylaxis. The lack of an effect after intravenous administration indicates a central site of action. This result is in agreement with the Yin Yang hypothesis and suggests that cGMP is a second transmitter in cardiovascular centres which may be involved in central cardiovascular effects in response to stimulation by putative neurotransmitter substances such as acetylcholine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00502571
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  • 30
    Electronic Resource
    Electronic Resource
    Hereditary deafness in the cat: An electron-microscopic study of the tectorial membrane (1980)
    Springer
    European archives of oto-rhino-laryngology and head & neck 229 (1980), S. 55-68 
    Details
    ISSN: 1434-4726
    Keywords: Erbliche Taubheit ; Katze ; Elektronenmikroskop ; Membrana tectoria ; Hereditary deafness ; Cat ; Electron microscopy ; Tectorial membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The tectorial membrane is affected at an early stage of the cochlear degeneration in the hereditarily deaf white cat. The membrane first descends towards the organ of Corti with obliteration of the intervening sub-tectorial space in the basal coil during the second post-natal week. Both the microvilli of supporting and Hensen's cells, and the hair cell stereocilia make deep indentations on the under-surface of the membrane. Cells are found insinuated between the tectorial membrane and Corti's organ, and numerous cellular processes occur within the former. A phagocytic function would appear probable for these cells, which seem to originate from the internal sulcus region. The membrane is retracted into the latter around the 2-month stage. At all ages, small spherical structures, which may represent altered interdental cell secretions, are found within the membrane, these becoming calcified in older animals.
    Notes: Zusammenfassung Veränderungen in der Membrana tectoria treten in einer frühen Phase der cochlearen Degeneration bei der weißen Katze mit erblicher Taubheit auf. Die Membran bewegt sich erst gegen das Cortische Organ mit Obliteration des dazwischenliegenden subtectorialen Raumes in der zweiten postnatalen Woche. Sowohl die Mikrovilli der Hensenschen Zellen und die der Stützzellen als die Stereozilien der Haarzellen machen tiefe Eindrücke auf der Unterseite der Membran. Zellen sind zwischen Membrana tectoria und dem Cortischen Organ gefunden, und viele zellulare Prozesse entstehen innerhalb Membrana tectoria. Eine phagocytotische Funktion würde für diese Zellen möglich sein, die aus der Region des Sulcus internus zu stammen scheinen. Bei älteren Tieren ist die Membran gegen den Sulcus internus retraktiert. Für alle Altersstufen findet man kleine spherischen Strukturen, die veränderte interdentale Zellensekrete vertreten können. Diese Strukturen werden innerhalb der Membran gefunden, und sind bei älteren Tieren verkalkt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00453752
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  • 31
    Electronic Resource
    Electronic Resource
    Inhibition of parasympathetic axonal sprouting in the cat submandibular gland by sympathetic axons (1980)
    Springer
    Cell & tissue research 207 (1980), S. 155-163 
    Details
    ISSN: 1432-0878
    Keywords: Submandibular gland ; Parasympathetic ; Sympathetic ; Nerve regeneration ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sprouting of parasympathetic axons into the submandibular sympathetic nerve trunk following sympathetic denervation has been investigated. It was found that a permanent sympathetic denervation was necessary in order for the sprouting to develop and be maintained: if reinnervation by adrenergic nerves was delayed, the sprouting developed but was reduced at longer survival times when the original innervation was reestablished. The evidence for suppression of the cholinergic sprouting by the adrenergic axons is discussed, as is the evidence that these sprouts arise from the submandibular gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239337
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  • 32
    Electronic Resource
    Electronic Resource
    The composition of the vagus nerve of the cat (1980)
    Springer
    Cell & tissue research 209 (1980), S. 423-431 
    Details
    ISSN: 1432-0878
    Keywords: Vagus nerve ; Sensory/motor fiber ratio ; Non-myelinated fibers ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The number and caliber of myelinated and non-myelinated fibers of entire and sensory vagal nerves of cats were studied by means of light and electron microscopy. The results obtained with electron microscopy show that the non-myelinated component is particularly rich (about 40,000 elements at the cervical level), with clearly higher numbers of fibers than demonstrated thus far with light microscopy. The ratio of myelinated to non-myelinated fibers is on the average 1∶ 4 for the total vagi and only 1∶ 8 for the sensory vagal component. The comparison of the nerve above and below the level of the nodose ganglion shows that (1) mean fiber diameter is usually greater at the infranodose than at the supranodose level, and (2) some myelinated fibers of small diameter occurring below the nodose ganglion become non-myelinated above it. Additionally, the number of non-myelinated fibers per Schwann cell is greater at the supranodose than at the infranodose level; this speaks in favor of a reorganization of the C-fiber population from one level to the other.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234756
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  • 33
    Electronic Resource
    Electronic Resource
    Glass transition in polyacrylonitrile: Analysis of dielectric relaxation data (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1125-1136 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Dielectric relaxation of polyacrylonitrile (PAN) samples, in which the presence of an amorphous phase is evidenced by x-ray diffraction, has been studied over the temperature range 30-150°C and frequency range 102-105 Hz. These data as well as those reported by other authors, reveal several points useful to the understanding of the dielectric relaxations of PAN in relation to its structure. A glass transition in PAN is evidenced by at least two of the four data sets investigated; the third shows combined effect of two relaxations, whereas the fourth clearly shows a relaxation process different from the glass transition. The glass-transition behavior of the dielectric relaxation data is confirmed by Williams-Landel-Ferry theory and a recent theory of Phillips, both of which lead to consistent conclusions.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.180180516
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  • 34
    Electronic Resource
    Electronic Resource
    Dependence of the conformational parameters of polyimides on the chemical structure of the chain (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1175-1186 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The flexibility of some polyimide chains has been studied theoretically as a function of the chemical structure of the repeat unit. It has been shown that the thermodynamic flexibility can be varied over a wide range by the choice of the unit structure. For three polyimides, as an example, the flexibility of cyclochain structures approximates that for free rotation.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.180180602
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  • 35
    Electronic Resource
    Electronic Resource
    High-temperature morphological transition in a styrene-butadiene-styrene block copolymer (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1237-1242 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Electron microscopy reveals a high-temperature morphological transition in a styrene-butadiene-styrene block copolymer of 7000 polystyrene block molecular weight and 43,000 polybutadiene block molecular weight (7S-43B-7S). Samples quenched in liquid nitrogen from temperatures above 150°C show no structure, whereas those quenched from temperatures below 140°C clearly show a multiphase structure. We previously reported that the 7S-43B-7S polymer exhibits a relatively sharp melt rheological transition in the temperature region between 140 and 150°C from highly viscoelastic and nonlinear viscous behavior to linear viscous behavior with insignificant elasticity. The dynamic viscoelastic properties are measured at different strain amplitudes in this study, and the results show that the melt rheological transition behavior is not influenced by the strain amplitude. This study clearly shows that the melt rheological transition in the 7S-43B-7S results from a morphological transition from a multiphase structure below about 140°C to a single-phase structure above about 150°C.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.180180606
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  • 36
    Electronic Resource
    Electronic Resource
    Model of sorption of simple molecules in polymers (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1103-1124 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A model of simple molecule sorption in polymers is proposed which embraces both the glassy and rubbery regions, and incorporates the successful dual-mode model below the glass-transition temperature. Hole filling is shown to be an important sorption mechanism both above and below Tg, although saturation effects do not occur in the rubbery polymer. The model interprets the “dual-mode” Langmuir and Henry's law parameters at the molecular level, and a simple statistical mechanical analysis allows estimation of the parameter values, as well as specifying certain interrelationships between the parameters. Applications of the model to gas solubility data in five polymers are considered [polyethylene (PE), poly(ethylene terephthalate) (PET), polystyrene (PS), polymethacrylate (PMA), poly(vinyl acetate) (PVAc)] and semiquantitative agreement is obtained for PE, PET, and to a lesser extent, PS. For PMA and PVAc, the agreement is qualitative only.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.180180515
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  • 37
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    Crystal orientation relaxation studies of polyethyleneSupported in part by grants from the National Science Foundation, the Army Research Office, and the Materials Research Laboratory of the University of Massachusetts. This research represents part of a cooperative program with Professor H. Kawai of Kyoto University supported jointly by the Office of International Programs of the National Science Foundation and the Japan Society for the Promotion of Science. (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1065-1085 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Wide-angle x-ray relaxation studies were performed on films of low- and high-density polyethylene (PE). The samples were rapidly stretched by a pneumatic stretcher and held at a fixed length. The rate of crystal reorientation was monitored by measuring diffracted intensity changes using a count-rate meter with output displayed on a storage oscilloscope as well as a digital counter-timer. Experiments were completed at several temperatures and activation energies comparable to those reported for the α1 relaxation in PE were obtained.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.180180513
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  • 38
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    Electronic Resource
    Model reactions for stereochemistry of Ziegler-Natta polymerization: Asymmetric hydroisomerization of α-olefins by chiral titanium tetra-alkoxides/tri-isobutyl aluminum catalytic systems (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2129-2142 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Homogeneous catalytic systems based on optically active low-molecular-weight and macromolecular titanium alcoholates and tri-isobutyl aluminum were used in the isomerization and hydrogenation of chiral and prochiral olefins. The reactions performed in a nitrogen and hydrogen atmosphere show a different behavior in regard to reaction rate, composition of reaction mixture, and stereochemical control. The catalyst based on macromolecular titanium alcoholate displays lower activity and a varying influence on the stereochemical pathway with respect to the catalysts based on low- molecular-weight alcoholates. The data obtained in both cases strongly support the absence of a stereocontrol by the growing chain in the stereoelective polymerization of racemic α-olefins by Ziegler-Natta catalysts based on optically active precursors. Finally evidence is provided in favor of the intermediate step responsible for asymmetric isomerization which does not occur via η-allyl complex.
    Additional Material: 5 Tab.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180709
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  • 39
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    Electronic Resource
    Stabilization at high temperatures (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2461-2470 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A general detailed model of polymer oxidative degradation in the presence of a stabilizer-oxygen acceptor was considered. The motion of the degradation zone boundary and the sample lifetime were obtained for various conditions of the process. In particular, it is shown that within the given concentration immobile oxygen acceptor has the best stabilizing properties. The theoretical results are compared with the experimental data obtained by using two independent methods: polymer sample cracking and a change in the ESR signal. Good agreement between theory and experiment was obtained.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180805
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  • 40
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    Electronic Resource
    Effects of ortho-substituents on reactivities, tacticities, and ceiling temperatures of radical polymerizations of phenyl methacrylates (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2197-2207 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Radical polymerization and copolymerization of some o-alkylphenyl methacrylates were carried out and the effect of the ortho-substituents on the ability to homopolymerize, on the monomer reactivities, and on the ceiling temperatures of the monomers was studied. The effect of the substituent on tacticities and thermal stabilities of the polymers formed was also discussed. The ability to honiopolymerize and the monomer reactivity were considerably decreased by the introduction of the o-substituent. 2,6-Di-tert-butylphenyl methacrylate formed no methanol-insoluble polymer at 60°C. On the basis of the tacticity determined it was noted that the o-substituted phenyl methacrylates preferred syndiotactic addition in the propagation reaction less than did phenyl methacrylate or methyl methacrylate. The polymers formed from the o-substituted monomers were thermally less stable than poly(phenyl methacrylate), and, consistent with this finding, ceiling temperatures of the o-substituted phenyl methacrylates seemed to be lower than that of phenyl methacrylate. The effects observed were characteristic of the o-substituents conformationally close to the carbon-carbon double bond of the monomer or the carbon carrying the unpaired electron of the polymer radical.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180715
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  • 41
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    Phenolic resins for solid-phase peptide synthesis. III. Copolymerization of acrylonitrile and p-acetoxystyrene and comparison of reactivity with styrene-based resins (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2239-2246 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerization of acrylonitrile (r1) and p-acetoxystyrene (r2) in bulk yields reactivity ratios r1 = 0.08 and r2 = 0.42. Crosslinked resins are readily obtained by a new type of precipitation copolymerization of acrylonitrile, p-acetoxystyrene, and divinylbenzene. After deacetylation, the phenolic groups afford useful attachment sites for protected amino acids as a first stage in solid-phase peptide synthesis. Reactivity of typical 10% functionalized polyacrylonitrile-based resins is comparable to that of the more usual polystyrene-based equivalents, although swelling characteristics of the two types of resin are very different.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180718
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  • 42
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    Electronic Resource
    Effect of unequal functional group reactivity and monomer masses on the polydispersity index in linear step polymerization (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2281-2291 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Macosko-Miller approach is used to obtain an expression for the polydispersity index for AA, BB, CC linear step polymerization system in which B and C are the same type of functional group. The dependence of the polydispersity index, as a function of the extent of reaction, on the monomer masses and on the relative reactivities of B and C groups toward A, is examined in detail.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180722
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  • 43
    Electronic Resource
    Electronic Resource
    Molecular defects of polyacrylonitrile formed in aqueous medium (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2307-2322 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The various kinds of molecular defect that are related to the thermal property of polyacrylonitrile (PAN) are studied in detail in relation to the polymerization mechanism in an aqueous medium. The existence of two different kinds of polymer radical is pointed out and the significance of polarity of radical species is emphasized. It is shown that the structural irregularity along the main chain is surely present but has little effect on the thermal property of PAN. It is estimated that one of the most significant defects relating to the thermal property is the main-chian type of branching the occurs predominantly in hydrogen on a polymer backbone. The relationship between activator (i.e., NaHSO3) incorporation and branch inhibition mechanisms is discussed. The optimum polymerization condition, under which the highest thermal quality of molecules is obtained, is found empirically within a limited experimental range, for an aqueous heterogeneous system.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180724
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  • 44
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    Electronic Resource
    Cationic polyelectrolytes. II. Amination of chloromethylated polystyrene with hydroxyalkylic secondary amines (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2333-2346 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of chloromethylated polystyrene with methyl(2- hydroxyethyl)amine and butyle (2-hydroxyethyl)amine was studied kinetically. The reaction of benzyl chloride with these amines was also investigated for comparison. N,N-dimethylformamide and dioxane were used as solvents. The reactions of benzyl chloride with the two amines in these solvents took place according to normal kinetics of the second order. Reaction kinetics depend on the nature of the amine and solvent in Chloromethylated polystyrene reactions. In dioxane the self-accelerating effect of the reaction for β ≃ 0.5 is apparent. Steric hindrance of the reaction, beginning with a conversion degree of about 75%, wss observed for butyl(2-hydroxyethyl)amine in N,N-dimethylformamide. This self-accelerating effect is observed in dioxane at the same reaction degree. The activation energies and frequency factors were calculated for the amination of benzyl chloride and chloromethylated polystyrene with the two amines in N,N-dimethylformamide and dioxane.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180726
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  • 45
    Electronic Resource
    Electronic Resource
    Photochemistry of polymeric systems. II. Photocrosslinking of polymers and copolymers containing various aromatic N-oxide groups (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2391-2410 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Methyl-5-vinylpyridine-N-oxide, 4-vinylquinoline-N-oxide. 9-vinylacridine-N-oxide, p-N,N-dimethylaminostyrene-N-oxide units were introduced in polymeric chains as homopolymers or/and as styrene copolymers to study their photocrosslinking. The method used for characterization of photocrosslinked films was a “photoresist test” described in Part I of this series. The photosensitivity of the different chromophores bound to the different polymer has also been studied by UV, IR, and fluorescence spectrophotometries. The use of aromatic amine N-oxide groups in polymers seems to be a general means to produce their photocrosslinking by radical reactions. Among the different polymeric materials prepared, 4-vinylpyridine-N-oxide and 4-vinylquinoline-N-oxide are the most photosensitive.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180730
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  • 46
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    Electronic Resource
    Solid-state polymerization of long-chain vinyl compounds. IV. Effects of chain length on the polymorphic behavior and postpolymerization of n-alkyl methacrylates (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2437-2449 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymorphic behavior and γ-ray-initiated postpolymerization of the even-numbered long-chain Methacrylates (C18-C12) have been investigated. Phase transition behaviors of octadecyl, hexadecyl, tetradecyl, and dodecyl methacrylates are respectively, which become simpler with shortening of the chain length. The methacrylate monomers with sufficiently long hydrocarbon chains, such as octadecyl and hexadecyl, can be polymerized rapidly in the α-form crystal (hexagonal packing) by a fully two-dimensional mechanism, whereas in the β-form crystal (triclinic packing), polymerization can hardly occur. In the case of dodecyl methacrylate, however, an accelerated polymerization in the β form occurs after an induction period of several hours and the resultant polymer is gel-like. This can be interpreted by the propagation reaction across the polymer chain already formed. It has been found that the solid-state post-polymerization of n-alkyl methacrylates is affected by the chain length through the packing mode of the monomer molecules and also by the aggregation state of side chains in the resultant comblike polymer.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180803
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  • 47
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    Electronic Resource
    Studies on suspension and emulsion. XXXV. Effect of epoxy groups at the surface layer of ethyl acrylate-glycidyl methacrylate copolymer emulsion particles on its crosslinking reactivity (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2451-2459 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of epoxy groups at the surface layer of ethyl acrylate-glycidyl methacrylate copolymer (1) emulsion particles on its crosslinking reactivity has been investigated. For this purpose two series of I emulsions were prepared. In the Y series, of which emulsion particles have epoxy groups at the surface layer, the epoxy content in the polymerization recipe was varied. For preparing the X series, of which emulsion particles have few epoxy groups at the surface layer, the high epoxy content of a given emulsion was reduced by various degrees of cleavage reaction with HCl-CaCl2. In emulsion blend films with amine-group-containing copolymer (II) emulsion, where the crosslinking reaction was expected to proceed only at the interfacial layer of I and II emulsion particles, the Y series, compared to the X series at the equal overall epoxy content in particles, showed less swelling and higher gel fraction in dioxane, less swelling in water, and higher tensile strength and modulus. On the other hand, this difference was not observed in the next two crosslinked films in which crosslinking was expected to be homogeneous. First, blends of I and II, which were isolated from the corresponding emulsions discussed above, were cast from dioxane solutions. Second, I emulsions were cast with BF3 ether complex which was expected to penetrate into the particles. It is concluded that the response of I emulsion cleaving the epoxy groups at the surface layer of particles to subsequent interfacial crosslinking is obviously reduced. However, even such an emulsion can be crosslinked to an extent similar to that of an uncleaved emulsion with similar overall epoxy content, if the crosslinking reaction is conducted so as to give an homogeneous effect.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180804
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  • 48
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    Electronic Resource
    Synthesis of 1,1-dichloro-2,2-bis(4-hydroxyphenyl)-ethylene via ammonia or methylamine dehydrochlorination. A bisphenol for the preparation of highly flame-resistant polycarbonates (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2501-2511 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ammonia used as both reactant and solvent has been shown to dehydrochlorinate 1,1,1-tri-chloro-2,2-bis(4-hydroxyphenyl)ethane smoothly to 1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene. The reaction is complete in 1 hr at 100°C, and after two crystallizations from methanol/water affords polymerizable quality monomer for the synthesis of highly flame-resistant polycarbonates. The use of organic solvents in combination with ammonia does not offer any rate advantages over pure ammonia. Primary and secondary amines also can be used to effect the dehydrochlorination but, except for the methylamine, are significantly less reactive and lead to less pure product than amonia.
    Additional Material: 4 Ill.
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  • 49
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    Electronic Resource
    Polymeric p-benzoquinone-tin derivatives as thermal stabilizers for rigid poly(vinyl chloride). I. Preparation of the stabilizers (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2513-2521 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of p-benzoquinone with tin tetrachloride in the absence of solvents was investigated by isolation and identification of the reaction products. This reaction leads to the formation of polymeric quinone-tin derivatives free from combined chlorine, chlorinated quinones, quinhydrone, and minute amounts of CI2 and HCI gases. The tin content varies accroding to the molar ratios of the reactants and reaches its maximum (72%) at the smallest SnCI4 ratio. The existence of the Sn-Sn bond in the polymeric derivatives was confirmed chemically and spectroscopically. A mechanism based on the formation of radical intermediates which can account for the reaction products was developed. In view of their quinonoid nature, high thermal stability, and the presence of Sn-Sn bonds, the polytin derivatives are to be investigated as radical traps in the stabilization of polymeric arcticles against radical degradation process.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180810
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  • 50
    Electronic Resource
    Electronic Resource
    Polymeric p-benzoquinone-tin derivatives as thermal stabilizers for rigid poly(vinyl chloride). II. Evaluation of the stabilizing efficiency (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2523-2533 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymeric p-benzoquinone-tin derivatives obtained from the reaction of p-benzoquinone with tin tetrachloride in the absence of solvent have been investigated as thermal stabilizers for rigid PVC at 200°C by measuring the rate of dehydrochlorination. The results reveal the greater stabilizing efficiency of the investigated products in relation to dibutyltin maleate and the basic lead stabilizers commonly used in industry. Evidence has been accumulated that the quinone and metallic elements (Sn—Sn bonds) of the stabilizer participate in the stabilization process by trapping the radical intermediates of degradation and blocking the odd electron sites formed on the polymer chains. Although stabilizers with high quinone content provide greater stabilization in the early stages of degradation, their efficiency sharply decreases in subsequent stages. On the other hand, stabilizers of high tin content effectively prohibit the dehydrochlorination reaction at all stages of degradation. On an equivalent basis of metal content, the results clearly demonstrate the greater stabilizing efficiency of tin atoms when found in direct contact in the stabilizer molecule. The mechanism of stabilization suggested to account for the results obtained may be considered as additional evidence in support of the radical nature of the dehydrochlorination reaction.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180811
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  • 51
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    Microstructural order in cotton fibers by relative availability of O(3)H: Never-dried fibers (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2577-2583 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Availabilities of O(3)H relative to O(2)H (that is, [O(3)H]a/[O(2)H]a) on accessible surfaces of microstructural units of cotton fibers were measured by chemical microstructural analysis (CMA). CMA involves a mild chemical reaction with N,N-diethylaziridinium chloride, determination of substituent distribution for this product and a corresponding product from decrystallized cellulose, and simple computations. Measurements for fibers in commercial cotton fabric, for field-dried fibers, and for never-dried fibers are reported. The [O(3)H]a/[O(2)H]a, an inverse measure of intact O(3)H ·· O(5′) bonds, decreased in the stated order; thus, intact O(3)H ·· O(5′) hydrogen bonding increased in this same order. Results indicate a high degree of order in intramolecular bonding in the never-dried fiber and an increasing disruption of this bonding as the never-dried fiber is dried and processed.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180816
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  • 52
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    Peel adhesion and viscoelasticity of rubber-resin blends (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2597-2608 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mixtures in various proportions of natural rubber (NR) and each of two tackifier resins, a poly-β-pinene and a modified pentaerythritol rosin ester, were used as the adhesive layer in joining a flexible polyester strip to a plane glass substrate. Measurements of the force required to peel the strip from the glass at a 90° angle were made over a range of pulling rates at several temperatures. Application of time-temperature superposition enabled a master curve of (reduced) peel force versus (log) pulling rate at a standard temperature (296 K) to be obtained for each adhesive composition. The master curves showed, in increasing order of pulling rate, some or all of four different modes of peeling: (i) peeling with viscous adhesive response, (ii) peeling with rubbery response, (iii) oscillatory or slip-stick peeling, and (iv) peeling with glassy adhesive response. In general, transitions between the different peeling modes were quite abrupt. Increase in concentration of tackifier resin caused displacement of the master curve toward lower pulling rates [an effect interpreted in terms of an increasing adhesive glass temperature (Tg)], and a superimposed displacement of the transition between peeling modes (i) and (ii) toward higher pulling rates-an effect attributed to reduction in adhesive average molecular weight. The influence of the tackifier resin in modifying the viscoelastic characteristics of the adhesive was further demonstrated in a comparison of the peel force master curves with corresponding master curves of dynamic storage modulus.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180818
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  • 53
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    Polymerization in water-in-oil microemulsion systems. I (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2641-2648 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Phase diagrams for monomer (methyl acrylate containing microemulsions) are shown and described. Polymerizations of a series of microemulsified monomer reveals the expected linear dependence of 1/DS vs. [S]/[M] for pentanol acting as a chain transfer agent and giving a value of 5.1 × 10-4 for Cs. No break in molecular weight behavior was shown as a result of micellization at higher water contents. A comparison of molecular weights obtained by various classical methods (solution, emulsion, bulk) are also given.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180822
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  • 54
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    Tricarbonylchromium-complexed phenylsiloxane polymers as stereoselective hydrogenation catalysts: Preparation and properties (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2663-2676 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Soluble tricarbonylchromium complexes were made by reacting Cr(CO)6 with a ladder polyphenylsilsesquioxane and a linear polydiphenylsiloxane. These new polymer Cr(CO)3 complexes were characterized by elemental Cr, infrared (IR), gel permeation chromatography (GPC), viscosity, and thermal analyses and were evaluated as stereoselective hydrogenation catalysts. Thermogravimetry studies demonstrated that the new complexes were more stable at 180-200°C in N2 than the corresponding complex from crosslinked polystyrene. These silicone polymer complexes catalyzed stereoselective hydrogenation of methyl sorbate to cis-3-hexenoate in cyclohexane and tetrahydrofuran (THF) and could be recovered from THF for recycling by precipitation-fiItration. Catalytic activity and recyclability, however, were highly influenced by the solvent. Loss of catalytic activity associated with loss of Cr(CO)3 was observed on recycling. These results support a mechanisim that involves dissociation of Cr(CO)3, a significant portion of which cannot become reassociated with the polymer phenyl groups.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180824
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    Phase transfer-catalyzed nitromercuration of diene polymers (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2723-2729 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A mild, efficient method of nitrating olefins was described recently by Corey and Estreicher. Application of their procedure to diene polymers failed because of the insolubility of the hydrophobic polymer in the aqueous nitromercuration regent. Use of water-immiscible organic cosolvents gave slow nitromercuration with substantial formation of nitrite esters. To overcome these problems a nonaqueous phase transfer-assisted method of rapid selective nitromercuration of diene polymers was developed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180828
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  • 56
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    Photochemical degradation of blends of polystyrene and poly(2,6 -dimethyl-1,4-phenylene oxide) (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2737-2746 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Blends of polystyrene and poly(2,6-dimethyl-1,4-phenylene oxide) that cover the entire compositional range have been subjected to the action of singlet oxygen from microwave discharge, dye-sensitized reaction, and photochemical oxidation. With the applied analytical technique, which consisted of infrared (IR) analysis, including ATR technique and a spectroscopic method combined with chemical analysis for hydroperoxide groups, it was not possible to detect any effect of the singlet oxygen treatment. For that reason singlet oxygen does not appear to be important to the initiation of the photooxidation of these blends. In connection with photochemical oxidation the interaction observed between the two components probably involves energy transfer from PS to PPO. This interaction results in the enhancement of reactions in PPO that lead to greater carbonyl group formation and crosslinking. Simultaneously, the probability of chain scission in the PS is lowered with increased PPO content, found by determining the changes in the molecular weights.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180830
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  • 57
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    The effect of solvents on the radiation-induced polymerization of ethyl and isopropyl vinyl ethers (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2773-2784 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The radiation-induced cationic polymerization of ethyl and isopropyl vinyl ethers was studied in a variety of solvents. The propagation rate constants were estimated and found to vary widely with the nature of the solvent. In particular, a good linear relationship existed between the logarithms of the rate constants and the reciprocal of the dielectric constants. The lowest rates were those of the highest dielectric constant solvents. These results have been interpreted in terms of the Laidler and Eyring theory of ion-molecule reactions. Isopropyl vinyl ether polymerizes much faster than ethyl vinvl ether, although the rates approach the same value at infinite dielectric constant. In contrast, “free” carbenium ion polymerizations initiated by stable carbenium ion salts in methylene chloride solution had similar values for both monomers. A comparison is made between the rate constants obtained with both methods of initiation.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180902
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  • 58
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    Synthesis of polymer containing lipoic acid as a polymeric reagent for acyl transfer (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2793-2802 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Lipoic acid was immobilized on crosslinked polystyrene beads to generate a polymeric reagent. The acyl transfer reaction of the p-nitrobenzoyl group from the polymer-bound lipoic acid to cyclohexylamine was investigated spectrophotometrically and was compared with a monomeric model compound. The acceleration effect of silver ion on the acyl transfer reaction also was studied.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180904
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  • 59
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    On the rate of soapless emulsion polymerization of methyl methacrylate (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2811-2821 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rate of soapless emulsion polymerization is studied experimentally and theoretically. The soapless emulsion polymerization of methyl methacrylate (MMA) in water is carried out with potassium persulfate as initiator. It is shown that the soapless emulsion polymerization of MMA gives different time-conversion and time-average molecular weight curves from those of bulk and emulsion polymerizations. Comparing the experimental results with those of the other types of polymerization, features of the rate of soapless emulsion polymerization are discussed and a kinetic model is proposed to apply the soapless emulsion polymerization of MMA in water. The experimental results can be well expressed by this model.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180906
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  • 60
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    A chemical study of thermally activated chromic titanate on silica ethylene polymerization catalysts (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2857-2866 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermally activated ethylene polymerization catalysts which contain chromium and titanium on silica differ from those catalysts which contain only chromium on silica. The characteristics of chromium-titanium catalysts vary with the method of incorporating the titanium and the thermal activation procedure. Titanated catalysts of the kind examined in this article have faster initiation and a higher polymerization rate per unit catalyst weight than corresponding catalysts without titanium. High-density polyethylene produced by this type of titanium-chromium catalyst tends to have a higher melt index and a broader molecular weight distribution than polyethylene made with chromium on silica catalysts. Iodometric titration showed that reduction from the initial hexavalent chromium to trivalent occurs when the dry, catalyst starting material is treated with titanium tetraisopropoxide. A study of the reaction between chromium trioxide and titanium tetraisopropoxide in carbon tetrachloride revealed that (1) it is not necessary to have a reaction between surface silanols and titanium tetraisopropoxide for the reduction to occur, and (2) the reaction product has an absorption near 660 nm in the visible range. Comparison of spectra showed that chromium trioxide on silica reduced by isopropyl alcohol has a shifted absorption, i.e., 600 nm. These findings are interpreted to mean that titanium atoms come sufficiently close to chromium atoms to change their electron density in the starting material and remain close neighbors in the activated catalysts. The interpretation is further supported by ESCA data and leads to the proposal that in this case the activated catalysts contain titanium chromate structures.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180908
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  • 61
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    Solvating properties of certain polymeric ethersDedicated to Professor C. G. Overberger on occasion of his 60th birthday. (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3059-3067 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The formation of two kinds of solvation complex of poly(ethylene oxide), polydimethoxyethylene, and polydioxene with some alkali derivatives of fluorene in dioxane was found, differing in the ionic species of the fluorenyl metal in the complex. Additional evidence was found for the existence of peripherally solvated ion pairs of fluorenyllithium, -sodium, and -potassium. It was shown that polydimethoxyethylene and polydioxane interact with different cations in a different manner. The complexing ability of poly(ethylene oxide) and polydioxane with respect to fluorenyllithium, -sodium, and -potassium, and of polydimethoxyethylene for fluorenyllithium, was proved to be stronger than that of their monomer analogs - dimethoxyethane and dioxane. This was explained by the effect of the polymer chain.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170181015
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  • 62
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    Configurational rules governing the stereochemical control of chiral initiators in ring-opening polymerizations of heterocyclic monomers (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3089-3099 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Configuration rules were established for the polymerization of cyclic monomers with chiral initiators. The latter recognize in the monomer an asymmetric carbon of homochiral configuration. The chirality of the initiator is defined by the “local” asymmetry of the ligand and by the overall asymmetry of the particular arrangement of catalytic aggregates. Two types of process called “homosteric” and “antisteric,” which apply to the polymerization of resolvable monomers and achiral monomers of meso structure, are defined. These configurational rules have a general character and are verified in many examples of differently substituted three- or four-membered cyclic monomers (oxiranes, thiiranes, β-lactones). Stereoelective polymerization appears to be an original method for the determination of the absolute configuration of some monomers of unknown chirality.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/pol.1980.170181018
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  • 63
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    Sequence distribution of methyl acrylte-vinylidene chloride copolymers by 13C-NMR (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3307-3310 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170181116
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    Heterogeneous catalysis by polyelectrolyte. I. Polyelectrolyte influence on the solvolysis and deamination (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3289-3296 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Heterogeneous or homogeneous polyelectrolyte influences on the solvolyses of t-butyl chloride and α-phenethyl chloride were studied. Anionic polymers enhanced the reaction rate by stabilizing the intermediate point dipole (ionic strength effect); cationic polymers with chloride ions as gegenions retarded the reaction by the mass action law (common ion salt effect), thus supporting the theory of Ingold et al. On the other hand, neutral polymer resins retarded the reaction probably because of the binding of the substrate on the resin surface. By the addition of a neutral polymer resin. Amberlite XAD-4 the net steric course of the solvolysis of α-phenethyl chloride was slightly changed from inversion to racernization, whereas anionic resins (Amberlite IR-124) showed no effect. The heterogeneous polymer resin effect on the dearnination of α-phenethyl amine was also studied. An anionic resin (IR-124) retarded the reaction slightly and a neutrai resin (XAD-4) retarded it to a great extent. A cationic resin (Dowex 1 × 8) accelerated the reaction, although slightly. The net steric course of the deamination was changed from inversion to racemization in the order XAD-4 〉 Dowex 1 × 8 〉 IR 124. The heterogeneous polymer effect of the stereochemistry depended mainly on the hydrophobicity: i.e., the ability to bind the substrate on the surface of resin.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170181114
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    Radiation-induced polymerization at high dose rate. IV. Chloroprene in bulk (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3297-3305 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bulk polymerization of chloroprene was studied at 25°C in a wide does rate range. Variations of the rate of polymerization (Rp) and molecular weight as a function of does rate were essentially the same as those in several monomers that are capab;e of radical and cationic polymerizations. The polymerization proceeds with radical mechanism at low dose rate ans with radical and cationic mechanism concurrently at high dose rate. The number-average molecular weight of the high-dose-rate was ca. 2400. Microstructure of the polymers was mainly of trans-1,4 unit with small fraction of cis-1,4 and 3,4-vinyl unit. Fractions of the vinyl unit and the inverted unit in trans-1,4 sequence which increased at high does rate inflected the change of dominant mechanism of polymerization.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170181115
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  • 66
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    Grafting vinyl monomers onto silk fibers. XII. Graft copolymerization of methyl methacrylate onto silk using hydrogen peroxidesodium thiosulfa te redox system (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3315-3317 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170181117
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  • 67
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    Synthesis and metal binding properties of novel sulfur-containing functional oligomerPart 8 of “Non-Classical Urea Oligomers” series for Part 7, see ref. 1. (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3359-3368 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis and metal ion binding properties of a new class of functional oligomers are described. Oligo[1-(N-phenylthiocarbamoyl)aziridine] (DP ca. 8) and its analogs are prepared by ring-opening oligomerization of the corresponding aziridine monomers in good yields. These oligomers contain sulfur groups capable of binding “soft” metal ions, and the selective binding properties of the novel oligomer for Cu(II) and Hg(II) ions are investigated by liquid-solid adsorption and liquid-liquid extraction experiments.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170181203
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  • 68
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    Radiation-induced polymerization at high dose rate. III. Isoprene in bulk (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3381-3391 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Radiation-induced polymerization of isoprene in bulk state was studied at 25°C in a wide dose rate range. Variations of the rate of polymerization and molecular weight of the products were essentially the same as those observed in the monomers which were capable of both radical and cationic polymerizations. At low dose rate, 7.0-230 rad/sec, radical polymerization took place. At high dose rate, 8.8 × 103-2.2 × 105 rad/sec, radical and cationic polymerizations took place concurrently. The average molecular weight of the high-dose-rate product was about 850, independent of dose rate. The microstructure of the products at high dose rate consisted mainly of trans- 1,4 units with only about 7% of cis- 1,4 and 10% of 3,4-vinyl units. The residual unsaturation in the high-dose-rate products was 90%. Decreases in cis units and residual unsaturation at high dose rate were accounted for by the change in predominant mechanism of polymerization with dose rate.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170181205
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  • 69
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    The synthesis of sulfonated polymers by free radical copolymerization. Poly(butadiene-co-sodium styrene sulfonate) (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3427-3439 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerization of butadiene with sodium styrene sulfonate was studied and the copolymer products characterized. In general these copolymers contain 0.5-4 mole% of sulfonated monomer. The effects of the following reaction variables are described: emulsifier type and concentration, monomers feed ratio, chain transfer agent concentration, and reaction conversion. The products were heterogeneous with regard to composition, molecular weight, and solubility behavior. Copolymers prepared under certain conditions exhibited strong intermolecular interactions derived from associations of the ionic species as observed in other ionomers.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170181209
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  • 70
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    Kinetics of the metal-catalyzed condensations of phenols and polyflavonoid tannins with formaldehyde (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3447-3454 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rate constants and free energies of activation of Zn2+ -accelerated and Cr3+ -retarded condensations of resorcinolic A rings of polyflavonoid wattle tannins, as well as of the model compounds resorcinol and catechol with formaldehyde, were determined. A quantitative indication of the effect of strong metallic ion catalysts on phenol/aldehyde reactions was obtained. Second-order kinetics have been found to fit these metallic ion-catalyzed reactions. The dependence of the tannin/formaldehyde reaction on the concentration of Zn2+ and Cr3+ under acid and alkaline reaction conditions has been investigated and the respective catalytic coefficients determined. In the presence of the metallic ions used the reaction proved to be considerably less sensitive to variations of OH-concentration, hence of pH.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/pol.1980.170181211
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  • 71
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    Starshaped block copolymers. I. Synthesis of new A(B)2 starshaped block copolymers based on vinyl or diene hydrocarbons (A) and oxirane (B) (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3483-3498 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Naphthalene-terminated polyvinyl aromatics and polyisoprene were obtained successfully. These functional polymers were metalated by potassium in THF at 25°C. The formation of a stable dinegative ion is observed unless the naphthalene is directly attached to the end of the polyvinyl aromatics, in which case a few isoprene units can be advantageously inserted between the naphthalene end group and the polyvinyl aromatics. The polymeric and stable dinegative ion polymerizes oxirane by both anionic sites and forms three-branched starshaped block copolymers.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170181215
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    Relationships of graft polymerization of vinyl monomers onto cellulose. Reaction kinetics and polymer structurePresented at the Fifth Conference, “Modified Polymers, Their Preparation and Properties,” Bratislava, Czechoslovakia, July 3-6, 1979. (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3369-3379 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Graft polymerization of acrylamide and sulfuric salt of 2-methyl-5 vinylpyridine onto cellulose using CO(III) salts was studied. It was shown that graft polymerisation of water-soluble polymers can be described by general relationships of radical reaction. The relation between elementary reaction constants of the formation and termination of active centers in cellulose, as well as relation between constants of the propagation, transfer and termination of chains were determined for different cellulose materials and monomers. The translational diffusion, sedimentation, viscosity, and flow birefringence of copolymers have been investigated in different solvents. Experimental data showed that the copolymers obtained are graft copolymers with two to five grafted chains onto macromolecules. The minimum distance between the branch points is 100 ± 20 glucoside units. The peculiarity of these copolymers is relatively low polydispersity. The conformation of macromolecules of such copolymers in solution depends on the compatibility of the copolymer components and the thermodynamic properties of the solvent.
    Additional Material: 5 Ill.
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  • 73
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    Synthesis and polymerization of γ-alkoxy-β-hydroxypropyl acrylates (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3403-3411 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several γ-alkoxy-β-hydroxypropyl acrylates were synthesized and polymerized. Both poly(MHPA) (IVd) and poly(MHPMA) (IVa) hydrogels possess high values of equilibrium water content, about seven and three times, respectively, that of the poly(β-hydroxyethyl methacrylate) hydrogel. These rather high values are attributed tentatively to the presence of a hydrophilic γ-methoxy-β-hydroxypropyl side group on the acrylic backbone.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170181207
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  • 74
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    Synthesis and radiation degradation of vinyl polymers with fluorine: Search for improved lithographic resists (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 3413-3425 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Homopolymers of methyl α-fluoroacrylate (MFA), trifluoroethyl methacrylate (TFEM), and hexafluoroisopropyl methacrylate (HFIM) were prepared, as were their methyl methacrylate (MMA) copolymers. Copolymers of vinylidene fluoride (VDF) and chlorotrifluoroethylene (CTFE) with MMA were also prepared. The radiation susceptibilities of these polymers were measured by the 60Co γ-irradiation method, in which molecular weights were measured by membrane osmometry and gel permeation chromatography (GPC). All the copolymers degraded by predominant chain scission except poly(methyl α-fluoroacrylate), (PMFA), which crosslinks even at low doses (ca. 1 Mrad). The Gs - Gx and Gs values of the chain scissioning polymers and copolymers are higher than those of poly(methyl methacrylate) PMMA reference. The high susceptibility of PMFA homopolymer to crosslinking is in contrast to that of poly(methyl α-chloroacrylate), as we reported earlier. This effect is interpreted as resulting from extensive hydrogen fluoride and polyenlyl radical formation, which leads to facile crosslinking. However, incorporation of the MFA monomer unit causes the (22/78) MFA/MMA copolymer to degrade with a larger value of Gs that PMMA. Apparently a second-order process leads to crosslinking in PMFA and this is retarded in the copolymer. In the hehomopolymers of HFIM and TFEM and in the HFIM-MMA and TFEM-MMA copolymers the HFIM and TFEM components facilitate degradation with negligible crosslinking. The increased degradation susceptibility of VDF and CTFE copolymers with MMA over that of PMMA is attributed to processes at the VDF or CTFE components present in smaller concentrations (3-5 mole %) than the threshold levels (25-50% necessary for significant crosslinking).
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170181208
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  • 75
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    Kinetic evidence of a “matrix effect” in the bulk polymerization of acrylonitrile (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 327-333 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of the γ-ray-initiated polymerization of acrylonitrile in bulk are reexamined in broad ranges of temperatures and radiation dose rates. The discussion of the results coupled with an analysis of earlier data indicate that the polymerization of acrylonitrile proceeds by different mechanisms depending on the reaction temperature. Above 60°C the precipitated growing chains recombine readily; therefore, the autoaccelerated conversion curves cannot be accounted for by an “occlusion effect.” It is suggested that autoacceleration is caused by a fast propagation taking place in oriented monomer aggregates which result from dipole-dipole association of the monomer with the polymer chains formed in the early stages of the reaction (“matrix effect”). Below 10°C the precipitated growing chains are buried in the dead polymer and monomer diffusion toward the occluded chain ends is very limited (“occlusion effect”). Between 10 and 60°C the system gradually changes from one dominated by “occlusion” to one where the “matrix effect” determines the kinetic behavior. The conclusion based on kinetic data is in agreement with results obtained from studies of the postpolymerization in these various systems.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180131
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  • 76
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    Reactivity of N,N′-bismethylolpyromellitimide with isocyanates (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 355-357 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180136
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  • 77
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    Studies of poly-yne polymers containing transition metals in the main chain. 5. A design of metal arrangement in polymer backbone (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 349-353 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180135
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  • 78
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    Kinetics of the hydrolysis of linear poly[(acylimino)ethylenes] (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 380-380 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180143
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  • 79
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    Plasma polymerization. III. An ESCA investigation of polymers synthesized by excitation of inductively coupled RF plasmas in perfluorocyclohexa-1,3- and 1,4-dienes, and in perfluorocyclohexeneThis is Part XXVIII of the series “ESCA Applied to Polymers.” (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 407-425 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The plasma polymers prepared from perfluorocyclohexa-1,3-diene, perfluorocyclohexa-1,4-diene, and perfluorocyclohexene have been investigated by ESCA. The carbon-to-fluorine stoichiometries of the diene-derived polymers are similar and close to that of the starting material. The polymer prepared from perfluorocyclohexene is depleted in fluorine compared to the fluorine content of the “monomer.” The polymers prepared in nonglow regions are also studied and shown to be high in CF2 derived species. The results are compared with those for perfluorobenzene and perfluorocyclohexane, and the polymerization rates are in the order C6F6 〉 C6F8 1,3 ∼ 1,4 〉 C6F10 ∼ C6F12. The variations in composition of the plasma polymer as revealed by ESCA as a function of the polymerization conditions are discussed.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180202
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  • 80
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    Copolymerization of liquid sulfur with certain olefinic systems and structure-property studies on the polymeric materialsAbstracted in part from a dissertation submitted to the Departments of Chemistry and Chemical Engineering, Polytechnic Institute of New York, in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Polymer Science and Engineering, 1979. (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 383-406 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Liquid sulfur-olefinic reactions at 140°C forming crosslinked polysulfide polymers have been investigated. A systematic approach to the characterization and some structure-property studies on these new polymeric materials has been presented. The olefinic systems of interest are endo-and exo-dicyclopentadiene and an oligomeric alkenyl polysulfide. Equimolar S8-olefinic system copolymers are amorphous and they show no tendency for sulfur crystallization. A correlation has been drawn between chemical structure and glass transition temperature of the copolymers and terpolymers. Mechanical properties and, in particular, chemical stress relaxation of the crosslinked polysulfide polymers have been investigated.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180201
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  • 81
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    Functional monomers and polymers. LXI. Photochemical reactions on the synthetic polymers containing thymine basesFor Part LX see ref. 13. (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 427-439 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photodimerization of N-2-isobutyloxyethyl thymine (T-M), bis[2-(5-methyl-1-primidinyl)-ethyl] glutarate (T-T), poly(N-2-methacryloyloxyethyl thymine) (polyMAOT), and poly(N-2-acryloyloxyethyl thymine) (poly AOT) was studied in dimethylformamide solution. The rate of intramolecular photodimerization of polyMAOT and polyAOT was 5.7 and 7.2 times faster, respectively, than that of T-T. In T-M, however, intermolecular photodimerization did not occur under the reaction condition used. Quenching studies with isoprene suggest that the photodimerization of T-T occurs predominantly in an excited triplet state, whereas that of polyMAOT and polyAOT occur in singlet and triplet states. It was concluded that the photodimers of T-T, polyMAOT, and polyAOT are two syn-fused cyclobutane-type dimers (cis-syn and trans-syn). Quantum efficiencies of thymine base disappearance were determined by ultraviolet (UV) analysis to be 0.0012 for T-T, 0.0084 for polyMAOT, and 0.010 for polyAOT.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180203
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  • 82
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    Reaction of cellulose phosphonate with N-vinyl-2-pyrrolidone and flame-retardant properties of the product (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 441-448 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of cellulose phosphonate and N-vinyl-2-pyrrolidone in ethanol in the presence of sodium ethoxide was investigated and thermal stabilities and flame-retardant properties for cellulose phosphonate modified with N-vinyl-2-pyrrolidone were discussed. The results in this study point out the following important aspects of flame retardation of cellulose fabrics: (1) The reaction of cellulose phosphonate and N-vinyl-2-pyrrolidone in the presence of sodium ethoxide results in graft polymerization of N-vinyl-2-pyrrolidone at P—H sites in cellulose phosphonate; an average chain length of the graft polymer is about five units of vinylpyrrolidone. (2) The graft polymerization of N-vinyl-2-pyrrolidone can improve both stabilities, especially the flame-retardant properties of cellulose fabrics. (3) Amides, whether noncyclic or cyclic, are suitable for nitrogen compounds that can effectively operate as synergists.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180204
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  • 83
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    Reactions of stabilizer compounds. IV. ESR studies of the formation of stable nitroxyl radicals in the photooxidation of polypropylene containing hindered amine light stabilizers (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 533-539 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ESR studies of the formation of stable nitroxyl radicals in the photooxidation of polypropylene containing 2,2,6,6-tetramethyl-4-hydroxypiperidine (II) and the commercial light stabilizer bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate (III) are described. Spectra of the stable nitroxyl radicals in solid polymer and in solution after extraction from the polymer were obtained. The extract from photooxidized polypropylene containing the bifunctional stabilizer (III) showed only the mononitroxyl radical. The possible formation of polymer-bonded nitroxyl radicals from (III) is discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180214
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  • 84
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    Chemical modification of poly(N-vinylcarbazole) by chloromethylation reaction (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 729-736 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chloromethylation reaction of poly(N-vinylcarbazole) was studied. The effect of the chloromethylating agent, catalyst, temperature, and reaction time on the course of chloromethylation reaction was investigated. The optimum conditions for introducing one chloromethyl group per one monomer unit were found. Thermal studies of chloromethylated poly(N-vinylcarbazole) were carried out.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180232
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  • 85
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    Polycondensation reaction of dimethyl tartrate with hexamethylenediamine in the presence of various matrices (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 939-948 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polycondensation reaction of dimethyl tartrate (DMT) with hexamethylenediamine (HMD) was carried out in dimethyl sulfoxide (DMSO) at 60°C in the presence of various polymer matrices, which were expected to interact with DMT or the resulting polyamide which had pendant hydroxyl groups due to hydrogen bonding. It was found that the rate of polycondensation was enhanced by polymer matrices such as poly(vinyl pyrrolidone) (PVP), Pullulan (polysaccharide) (PF), and poly(vinyl alcohol) (PVA). The rate enhancement became more pronounced with increasing molecular weight of the polymer matrix. When polycondensation in the presence of PVA was carried out in DMSO, a polymer complex was produced. The formation of the polymer complex between the resulting polyamide and PVA during polycondensation was dependent on the concentration of monomers and also on PVA; a gelation of the solution was observed at a concentration of PVA.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180315
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  • 86
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    Organosilane polymers. II. Poly(ethylmethyl-co-dimethylsilylene) and poly(methylpropyl-co-dimethylsilylene) (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 959-965 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polydimethylsilylene is a largely crystalline, high-melting polymer that is soluble only above 200°C and does not thermoform below its decomposition temperature. Introduction of ethyl and propyl substituents into the linear silylene system by random copolymerization of dimethylsilylene with ethylmethyl- and methylpropylsilylenes leads to tractable polymers that are soluble in common solvents at normal ambient temperatures.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180317
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  • 87
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    Functional monomers and polymers. LXIII. A study on the polymer-polymer interaction between nucleic acid base-substituted poly-L-lysinesFor Part LXII see ref. 1. (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 949-958 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A study of polymer-polymer interaction was made on several poly-L-lysines that contained pendant nucleic acid bases substituted on the N′ position. Conformation and interaction of these polypeptides were studied in solution by spectroscopic measurement. The results obtained suggest that the high-molecular-weight polymers form polymer complexes in a helical conformation by specific adenine-thymine base pairing. On the other hand, no interaction could be observed for the low-molecular-weight polymers, which existed in a random coil structure.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180316
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  • 88
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    Polymer flammability. II (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 987-1009 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The responses of a polymer flame to changes of specimen diameter, ignition position, and stability of the burning surface were determined. These extrinsic flame parameters restricted the transport of oxygen from the environment to the burning surface. With increasing restriction the oxygen demand from the environment for self-sustained combustion increased from a minimum oxygen demand at maximum access of environmental oxygen to the burning surface. This increase in oxygen demand was measured and correlated with surface oxygen concentrations estimated from the diffusion data of Part I. The minimum oxygen demand was demonstrated as characteristic for a given polymer and intrinsic in its chemical structure. This minimum oxygen demand, termed intrinsic combustibility, has been correlated with a polymer's thermooxidative stability, measured by thermogravimetric analysis at specific conditions. An intrinsic combustibility scale for polymers is given. In contrast, polymer flammability, as commonly measured in air, is interpreted as a variable property that depends on the extent of the interaction between extrinsic parameters, which are set by the testing configuration, with intrinsic combustibility.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180319
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  • 89
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    Evolution of aromatic compounds in the thermal decomposition of vinyl polymers (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1147-1153 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal decomposition products that evolve from poly(vinyl chloride) (PVC), poly(vinylbromide) (PVB), poly(vinyl alcohol) (PVA), and poly(vinylacetate) (PVAc) were analyzed by direct pyrolysis in the ion source of a mass spectrometer (MS). Our results indicate that in both stages of the decomposition process which occurred in the four vinyl polymers investigated several aromatic hydrocarbons were produced and that the relative amounts of benzene, napthalene, and anthracene were different in the two stages. This previously unreported information determines in a single scheme the thermal behavior of the title compounds.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180401
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  • 90
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    Utilisation du dicyclohéxyl-18 couronne-6 en polymérisation anionique. II. Polymérisation du methacrylate de methyle amorcee par les metaux alcalins (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1155-1161 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The purpose of the present work, relative to anionic polymerization, is to describe the use of DCHE in order to prepare stable alkali metal solutions in low-dielectric-constant solvents. All these new species initiate the polymerization of methyl methacrylate avoiding the inconvenience of heterogeneous reactions. The presence of complexed ion pairs increases the syndiotactic structure. The polymerization seems to obey the Bernoullian statistics.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180402
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  • 91
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    Polymérisation anionique de i'isoprene et du butadiene en presence d'agents complexants (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1163-1169 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: With the aid of DCHE and [222], solutions of sodium, potassium, rubidium, and cesium have been prepared in tetrahydrofuran (THF) and in benzene. All these new species initiate the polymerization of butadiene and isoprene avoiding the inconvenience of heterogeneous reactions. The presence of free ions and/or complexed ion pairs allows the increase of vinyl structures even in benzene.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180403
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  • 92
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    Grafting onto wool. IV. Effect of amines upon ceric ion-initiated grafting of poly(methyl acrylate) (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1171-1176 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Grafting of poly(methyl acrylate) onto wool has been carried out in an aqueous medium at 45 ± 1°C by using ceric ammonium nitrate (CAN) in the presence of triethylamine, diethylamine, n-butylamine, triethanolamine, and N,N-dimethylaniline. The percentage of grafting varied with the nature and concentrations of the amines. Reactivity of the different amines toward grafting reactions followed the order: triethylamine 〉 diethylamine 〉 n-butylamine 〉 triethanolamine ≥ N,N-dimethylaniline. In the presence of N,N-dimethylaniline grafting did not occur. An attempt has been made to explain the observed reactivity of Ce4+ in various amine systems in graft copolymerization reactions.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180404
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  • 93
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    Determination of initiation rate of copolymerization of acrylonitrile with p-bromophenyl acrylate carried out in N,N-dimethylformamide (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1177-1187 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Studies of the initiation rate of the copolymerization reaction of acrylonitrile with p-bromophenyl acrylate initiated by azobisisobutyronitrile in dimethylformamide at 60°C are reported. The inhibition method involved use of stable Banfield's radical (N-[1,1-dimethyl 3-(N-oxidophenylimine)butyl]-N-phenylaminyl oxide). In the case of acrylonitrile, a side reaction effect of the initiation with the stable radical was observed along with a retarding effect resulting from inhibition reaction products (2kdf)60AN = 8.2 × 10-4 min-1. During the inhibited homopolymerization of p-bromophenyl acrylate a very strong side initiation reaction effect results from the Banfield radical; the inhibition reaction products do not influence the further course of the polymerization reaction. Side initiation effects of the Banfield radical (BR) increase with increasing concentration of p-bromophenyl acrylate. The overall contribution of the side initiation reaction changes for different comonomer mixtures; with their compositions the actual changes are nonadditive. The inhibition reaction products do not influence the further course of copolymerization. The initiation rate in monomer mixtures depends on their composition and may be described by the following relation: $$ 2k_d f = (2k_d f)_{{\rm AN}} \times X_{{\rm AN}}^{1.1} + (2k_d f)_{{\rm pBrPhA}} \times X_{{\rm pBrPhA}}^{1.7} $$
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180405
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  • 94
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    Model for predicting the composition of copolyesters: Polymerization of terephthalic acid, 2,2′-oxydiethanol, and 2,2-dimethyl-1,3-propanediol (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1189-1202 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolyesters of two glycols and a dicarboxylic acid moiety are frequently made to obtain specific physical properties. In the synthesis of these polymers an excess of glycol is used in the ester-exchange reaction and then removed during the polycondensation reaction to form a high-molecular-weight product. A model has been developed to predict the final polymer composition. The derivation is based on equilibria of reaction species (free glycol, polymer chain ends, and ester links) and the relative vapor pressures of the two reacting glycols. Calculated results are compared with experimental results of poly(2,2′-oxydiethylene: 2,2-dimethyl-1,3-propylene terephthalate)s. There is good agreement between calculated and experimental compositions. The model can be used to calculate the glycol concentrations that must be used to make a specific polymer composition. This model should also be useful in the calculation of other mole ratios of glycol to dicarboxylic acid that will make the same composition.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180406
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  • 95
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    Thermal-induced conversion of maleic and fumaric acid anion radicals in poly(methyl methacrylate) (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1213-1221 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermal-induced conversion of maleic and fumaric acid anion radicals produced by γ irradiation at 77 K in poly(methyl methacrylate) (PMMA) was studied by electron spin resonance (ESR) and optical absorption spectroscopic measurements. The ESR spectra of these acid anion radicals change into two-line spectra with a line separation of ca. 10 G by thermal annealing. This spectrum is assigned to a protonated radical of each acid anion radical. Anion radicals of the solutes are relatively stable below the γ transition point of PMMA and the conversion reaction takes place near this point. This means that the molecular motion of matrix molecule affects the radical conversion reaction.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180408
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  • 96
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    Kinetics of radical polymerization. XXX. Polymerization of styrene in solution (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1223-1232 
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    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A study was made on the AIBN-initiated polymerization of styrene in benzene and dimethyl formamide at 50°C. The overall rate and the rate of initiation of the polymerization were determined and the number-average and weight-average molecular weights of the polymers formed were measured. The decrease in the rate and degree of polymerization with the decrease in styrene concentration was caused by the corresponding decreases in the rate constants of chain propagation and initiation steps. In the systems studied no chain transfer process occurred with an experimentally measurable rate.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180409
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  • 97
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    An investigation of the vacuum UV spectra of inductivity coupled RF plasmas excited in inert gases as a function of some of the operating parameters (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1233-1246 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The vacuum ultraviolet (UV) emission from inductively coupled radio-frequency (RF) plasmas excited in a series of inert gases has been studied as a function of the pressure and applied power of the system. The effects of discharge tube size and pulsing of the applied RF power are also considered and a comparison is made between RF and microwave excitation.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1980.170180410
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  • 98
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    Electronic Resource
    Syntheses of polyethylenimine containing asymmetric nucleic acid base derivatives as grafted pendants (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1247-1265 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparations of new model polymers of polynucleotides with linear polyethylenimine (PEI) backbones and optically active nucleic acid base derivatives as pending side chains are described. (±)-2-(Thymin-1-yl)propionic acid (II) and (±)-2-(adenin-9-yl)propionic acid (IV) were synthesized. These carboxylic acid derivatives were grafted onto PEI at the imino nitrogen by the p-nitrophenyl active ester method. The enantiomeric pairs of II were optically resolved with quinine to yield (-) and (+)-2-(thymin-1-yl)propionic acid (VII and VIII). VII and VIII were grafted onto PEI through amide bond by direct coupling with diethylphosphoryl cyanide to give optically active graft polymers. The related monomer and dimer model compounds were also prepared by the same method from diethylamine and dimethylethylene diamine, respectively.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180411
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  • 99
    Electronic Resource
    Electronic Resource
    Circular dichroism of polyethylenimine containing optically active thymine derivatives as grafted pendants (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1267-1277 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Optical properties of linear polyethylenimine containing optically active (+)- or (-)-2-(thymin-1-yl)propionyl group as grafted pendant were investigated by circular dichroism (CD) and compared with those of the related monomer and dimer model compounds. CD spectra of the polymer in neutral aqueous solution were different from those of related model compounds, which suggest that the polymer exists in some ordered conformation (at least locally) to allow exciton coupling of π-π* (B2u) transition in the base chromophores along the polymer chain. This ordered conformation tends to be randomized on heating. The effects of complementary base pairing on the CD spectra have also been studied by using a linear polyethylenimine containing (±)-2-(adenin-9-yl) propionyl grafts and its related monomer and dimer models.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180412
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  • 100
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    Electronic Resource
    Determination of sulfate and similar end groups in polymers [poly(methyl methacrylate) and polystyrene] by an improved dye interaction method (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 1279-1284 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It has been observed that in a benzene medium the carbinol base of a cationic dye reacts with a polymer with —SO3 Na and similar end groups that give rise to a reversible color formation of the dye cation. This reaction can be pushed to completion and consequent intensification of color by adding a benzene-insoluble acid such as citric acid. This principle has been applied to develop an improved dye interaction method of determining such end groups. The end groups values thus obtained by this method for different poly(methyl methacrylate) and polystyrene samples were found to be in fairly good agreement with those obtained by the dye partition (extrapolation) method.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180413
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