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  • 1980-1984  (186)
  • 1975-1979  (193)
  • 1965-1969
  • 1920-1924
  • 1850-1859
  • 1982  (186)
  • 1975  (193)
  • Physical Chemistry  (208)
  • Electron microscopy  (171)
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Years
  • 1980-1984  (186)
  • 1975-1979  (193)
  • 1965-1969
  • 1920-1924
  • 1850-1859
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Heat of fusion and lamellar structure of polyethylene single crystal mats (1982)
    Springer
    Colloid & polymer science 260 (1982), S. 564-569 
    Details
    ISSN: 1435-1536
    Keywords: lin. Polyethylene ; Single crystals ; Heat of Fusion ; DSC ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Recently published results for solution crystallized PE single crystals have shown, that the experimental heat of fusionΔH * is higher, if the solvent is exchanged to silicon oil (oil suspension samples) as compared with dried mats. This has been interpreted by the collapse of the original hollow pyramids during drying, inducing lateral defects within the lamellae. The present investigation does not confirm this unexpected result.ΔH * of dried mats (T c 66 to 91 °C) and of the corresponding oil suspension samples agree within the rather small limits of experimental error. The crystallinities as derived fromΔH *, density or WAXS are in excellent agreement. SEM micrographs of cold fractured dried mats show their spongy macromorphology, but TEM micrographs of stained ultra-thin sections reveal the lamellar morphology of the walls, consisting of curved lamellae and stacked hollow pyramides. If a dried mat is sintered at room temperature, a dense transparent film is obtained with a rather regular stacked morphology of large flat lamellae.ΔH * of these films agrees with that of the original mat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01422587
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  • 2
    Electronic Resource
    Electronic Resource
    Macromolecular transport in the spiral prominence (1982)
    Springer
    European archives of oto-rhino-laryngology and head & neck 236 (1982), S. 41-51 
    Details
    ISSN: 1434-4726
    Keywords: Prominentia spiralis cochleae ; Meerrettichperoxidase ; Elektronenmikroskopie ; Inner ear spiral prominence ; Horseradish peroxidase ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Transport of macromolecules in the spiral prominence of the guinea pig was studied after perilymphatic and intravenous horseradish peroxidase (HRP) injection. HRP was taken up by the spiral prominence epithelium from the perilymphatic space and in a much higher degree from the endolymphatic space. A highly endocytic ativity was shown by the stroma cells surrounding the spiral prominence vessel. HRP particles were stored in the cytoplasm within vesicles and vacuoles of different sizes and different contrasts. The mode of tracer storage in the spiral prominence epithelium and in the stroma cells from the morphological point of view suggests lysosomal digestion. HRP was transported from the perilymphatic space into the spiral prominence vessel lumen by means of vesicular transport through the vessel wall, while transport of the tracer from the vessel lumen into the perilymphatic space after intravenous injection was not observed.
    Notes: Zusammenfassung Nach perilymphatischer und intravenöser Applikation von Meerrettichperoxidase wurde der Transport des Makromoleküls in der Prominentia spiralis des Meerschweinchens verfolgt. Die Tracer-Partikelchen wurden aus dem perilymphatischen Raum und vornehmlich jedoch aus dem Ductus cochlearis in das Oberflächenepithel der Prominentia spiralis aufgenommen. Die das Vas prominens umgebenden Stromazellen nahmen relativ viel Meerrettichperoxidase auf, die im Zytoplasma in unterschiedlich großen und unterschiedlich kontrastreichen Vesikeln und Vakuolen abgelagert wurde. Die Art der zytoplasmatischen Ablagerung des Tracers in den Epithelzellen und den Stromazellen spricht vom morphologischen Aspekt her für einen lysosomalen Abbau. Meerrettichperoxidase wurde von der Perilymphe in das Lumen des Vas prominens transportiert. Dieser Transport erfolgte vesikulär durch das Gefäßendothel. Ein Transport des Tracers in umgekehrter Richtung wurde nach intravenöser Applikation nicht beobachtet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00464056
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  • 3
    Electronic Resource
    Electronic Resource
    Elektronenmikroskopische Befunde am Bindegewebe von Nervus und Ganglion vestibuli bei Morbus Menière (1982)
    Springer
    European archives of oto-rhino-laryngology and head & neck 236 (1982), S. 67-79 
    Details
    ISSN: 1434-4726
    Keywords: Menière's disease ; Vestibular nerve ; Vestibular ganglion ; Pathologic alterations ; Electron microscopy ; Morbus Menière ; Nervus vestibularis ; Ganglion vestibuli ; Pathologische Veränderungen ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Vestibularisganglien von 17 Patienten mit einem Morbus Menière wurden nach transtemporaler oder translabyrinthärer Neurektomie elektronenmikroskopisch untersucht. Als Vergleichsmaterial dienten drei Ganglien, die bei anderer Indikation entnommen wurden und vier postmortale Entnahmen von Ohrgesunden. Bei allen Menière-Präparaten zeigten sich am Bindegewebe gleichartige pathologische Veränderungen von unterschiedlich starkem Ausmaß. Sie bestanden in einer Zunahme des Kollagens, wobei sowohl unterschiedliche Kaliber des Faserquerschnittes als auch Veränderungen der Periodizität der Querstreifung beobachtet wurden. Aktive Fibroblasten und reaktive Schwannsche Zellen, die isoliert lagen, keinem Axon zugeordnet waren und deren z. T. hirschgeweihförmig verzweigte, dünne Zellausläufer Kollagenbündel umhüllten, wurden als Zeichen einer noch ablaufenden Kollagenbildung gedeutet. Die Blutgefäße wiesen häufig eine Vervielfachung der Basalmembran auf, die von einem mehrfach breiteren Saum einer homogenen Matrix umgeben war. Die Perizyten waren oft entweder nekrotisch oder teilweise nicht mehr zu beobachten. Die Endothelzellen wiesen in der Regel kein aktives Zytoplasma auf. Sie erschienen teilweise autolytisch. Die pinozytotische Aktivität erwies sich als auffallend verringert. Diese qualitativen Veränderungen im interstitiellen Gewebe könnten auf ein primär lokales pathologisches Geschehen im Bereich des Nerven und des Ganglions hinweisen.
    Notes: Summary Vestibular ganglia of 17 patients with Menière's disease, obtained by transtemporal or translabyrinthine neurectomy, were studied by electron microscopy. Three ganglia removed because of other disease and four ganglia of normal ears taken post mortem served as controls. The neuronal fibrous tissue of Menière cases showed without exception pathologic changes of various extent. The amount of collagen was increased, whereby different fiber diameters were observed as well as changes in the periodicity of cross banding. Signs of continuing collagen formation were found: active fibroblasts and an increased number of isolated Schwann cells without axons, showing deerhorn-like ramifications which enveloped collagen bundles. The blood vessels were frequently surrounded by multiple basal membranes and broad bands of homogenous matrix. The pericytes were either necrotic or nonexistent. The endothelial cell cytoplasma was usually not in an active state. Sometimes it seemed to be autolytic. The pinocytotic activity was strikingly diminished. These qualitative changes of the interstitial tissue might point to a local pathologic event in the region of the vestibular nerve and ganglion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00464059
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  • 4
    Electronic Resource
    Electronic Resource
    Chordoid sarcoma (extraskeletal myxoid chondrosarcoma) (1982)
    Springer
    Virchows Archiv 399 (1982), S. 61-78 
    Details
    ISSN: 1432-2307
    Keywords: Chordoid sarcoma ; Chondrosarcoma ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Evaluation of a series of 12 chordoid sarcomas suggests that there is a wider range of histological features in this entity then previously appreciated. Six of the lesions had a typical tumor cell organization and a mixture of cellular and myxoid stromal components, while the remaining cases were atypical because of a more solid growth pattern. Four of the 12 cases, that included both typically myxoid and more cellular examples, had small foci with hyalinized stroma segragating individual or small groups of tumor cells with and without lacunar spaces. Two atypical cases revealed more extensive and obvious chondrocytic differentiation in recurrent or metastatic lesions and in one of these, the histological pattern was that of mesenchymal chondrosarcoma. Ultrastructural examination of three cases revealed fine structural features of both the tumor cell population and extracellular matrix compatible with chondrocytic differentiation. Results of light and electron microscopy of this series of chordoid sarcoma add further support for categorizing this tumor with other malignant chondrocytic neoplasms. It is probable that chordoid sarcoma and extraskeletal myxoid chondrosarcoma represent the same entity and that this lesion has a close histogenetic relationship to mesenchymal chondrosarcoma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00666219
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  • 5
    Electronic Resource
    Electronic Resource
    Adenoma of the human pituitary producing growth hormone and thyrotropin (1982)
    Springer
    Virchows Archiv 395 (1982), S. 59-68 
    Details
    ISSN: 1432-2307
    Keywords: Adenohypophysis ; Electron microscopy ; Growth hormone ; Immunocytology ; Pituitary adenoma ; Thyroid-stimulating hormone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A pituitary adenoma removed by surgery from a 22-year-old man was studied by histology, immunocytology, transmission electron microscopy and immunoelectron microscopy. Clinically, the patient had acromegaly and euthyroidism with elevated blood GH concentrations. Blood TSH and T4 levels were within the normal range. Histologically, the adenoma was chromophobic and exhibited no PAS, lead hematoxylin, aldehyde thionin or Grimelius silver positivity. By the immunoperoxidase technique GH, β-TSH and α-subunit but no PRL, ACTH, α-endorphin, β-FSH or β-LH were demonstrated in the adenoma cells. Electron microscopy revealed adenoma cells which were similar to TSH cells and showed no resemblance to GH cells of nontumorous pituitaries or GH-secreting tumors. Immunoelectron microscopy demonstrated GH and β-TSH in the secretory granules. It is concluded that pituitary adenomas composed of TSH-like cells may secrete GH, resulting in acromegaly. Production of GH by adenomatous TSH cells cannot be explained on the basis of the one cell- one hormone theory. The question is raised whether bihormonal or multihormonal clones, capable of synthesizing more than one hormone, exist in the human pituitary. These cells are apparently dormant under normal conditions, but in the course of neoplastic transformation may undergo functional dedifferentiation and acquire the ability to produce two or more different hormones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00443484
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  • 6
    Electronic Resource
    Electronic Resource
    Endothelium and “silver lines” (1982)
    Springer
    Virchows Archiv 395 (1982), S. 133-144 
    Details
    ISSN: 1432-2307
    Keywords: Endothelium ; Permeability ; Electron microscopy ; Electrolytes ; Silver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The significance of endothelial “silver lines” was studied by TEM in rat aortas after perfusion with glutaraldehyde followed by silver nitrate. Standard TEM technique proved unsatisfactory (coarse silver granules, imprecise localization, artefacts). Exposure of the silver-treated aortas to photographic fixer markedly improved the image of the deposits leaving fine, stable, uniform “residual granules” about 100 Å in diameter. Most of these granules were localized along the intercellular junctions; they also tended to pool in the basement membrane beneath each junction. This image suggests that the Ag+ ions pass through the junction, and react with its contents as well as with the basement membrane beyond it. A scheme is proposed to explain the reaction of Ag+ ions with anions and negatively charged radicals within the junction. It is concluded that the “silver lines” represent not only a histochemical effect, but also the visualization of a transendothelial electrolyte pathway.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00429607
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  • 7
    Electronic Resource
    Electronic Resource
    The ultrastructure of human fibrosing alveolitis (1982)
    Springer
    Virchows Archiv 395 (1982), S. 181-199 
    Details
    ISSN: 1432-2307
    Keywords: Lung disease ; Electron microscopy ; Interstitial pneumonia ; Fibrosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This report describes the ultrastructural findings in 37 patients who underwent open lung biopsy which yielded diagnoses of fibrosing alveolitis. A spectrum of lesions are categorized for the capillary endothelium and its basement membrane, the interstitial space and its fibrocellular components, and the alveolar epithelium and its basement membrane. The findings typify the different pulmonary cellular reactions to injury. Evidence for cellular regeneration and death in both epithelial and endothelial cell populations include atypical epithelial cell proliferation, capillary basement membrane multilamination, decrease in capillary lumen size and prominent pericytic ensheathment of pulmonary capillaries. Within the interstitium of the lung, proliferation of collagen and elastic fibers are documented, but in addition, abundant myofibroblasts and smooth muscle cells are present. No ultrastructural evidence of immune complex deposition was found in this study. The morphologic findings of fibrosing alveolitis further support the widespread concept that the lung responds to various injuries in a similar manner and undergoes a common reparative response regardless of etiology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00429611
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  • 8
    Electronic Resource
    Electronic Resource
    Primary sarcoma of the gallbladder (1982)
    Springer
    Virchows Archiv 396 (1982), S. 91-102 
    Details
    ISSN: 1432-2307
    Keywords: Primary gallblader sarcoma ; Electron microscopy ; Histopathology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Six Swedish cases of primary sarcoma of the gallbladder from the period 1958–1973 and 1 case from 1975 were studied by light and electron microscopy. The literature was reviewed for the period after 1970. Ultrastructural features of sarcoma were investigated in order to exclude poorly differentiated carcinoma. One case was considered to be an embryonal rhabdomyosarcoma, three cases leiomyosarcoma and two were diagnosed as fibrosarcoma. One case, diagnosed as sarcoma of the gallbladder by light microscopy, was omitted because electron microscopical examination revealed a squamous cell carcinoma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428502
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  • 9
    Electronic Resource
    Electronic Resource
    Arrest and extravasation of neoplastic cells (1982)
    Springer
    Virchows Archiv 396 (1982), S. 73-89 
    Details
    ISSN: 1432-2307
    Keywords: Human malignant cells ; K-562 cell line ; Vascular arrest ; Endothelial attrition ; Extravasation ; Nude and lasat mice ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The morphological aspects of the arrest and extravasation of malignant cells of human origin (K-562 cell line) in the lungs of athymic (nude) and asplenic-athymic (lasat) mice were studied by electron microscopy examination of serial sections. The specimens were obtained at sequential stages after the sc inoculation into newborn mice of 107 malignant cells. K-562 cells (105) were also injected iv into control groups of nude and lasat mice to assess the influence of the route of inoculation on the in vivo behavior of K-562 cells. Our results demonstrated that K-562 cells were arrested and proliferated within the pulmonary capillaries without the participation of platelets or fibrin. The neoplastic cells extravasated by attrition and penetration of the endothelium (rather than by diapedesis) and continued to proliferate in the interstitial tissue of the lung, developing into neoplastic nodules. Following iv injection, K-562 cells induced the formation of platelet-tumor cell aggregates within the pulmonary capillaries. However, under these conditions, the neoplastic cells did not adhere to the endothelium nor did they proliferate or extravasate. These aggregates were flushed out by the circulation, restoring the permeability of the capillaries.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428501
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  • 10
    Electronic Resource
    Electronic Resource
    An ultrastructural and morphometric study of bladder tumours (II) (1982)
    Springer
    Virchows Archiv 396 (1982), S. 291-301 
    Details
    ISSN: 1432-2307
    Keywords: Electron microscopy ; Bladder neoplasms ; Measurement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Bladder tissues from 3 groups of patients were examined, using the light and electron microscopes (LM and TEM). One group of patients had a history of well-differentiated papillary transitional cell carcinomas and specimens were taken from cystoscopically normal areas. In a second group frank papillary carcinoma was biopsied. Finally, patients with no history of urothelial tumours and a normal cystoscopic appearance were biopsied during investigations for various benign conditions and these served as controls. In tissues from the first two groups certain differences were seen when these were compared to the controls and the frequency of these was significant. Light microscopic examination of 0.5 μ toluidine blue stained sections revealed an increased number of immature, small dark cells in the superficial layer of the epithelium (P〈0.001). Electron microscopic examination showed that in place of the characteristic asymmetric unit membrane of mature superficial cells, the surface was frequently covered with microvilli and the junctional complexes were often atypical. There was an increased number of abnormalities in the basal lamina (P〈0.001). These features were seen in the absence of cystoscopic and light microscopic changes in three out of eight patients with a history of tumours. It is, therefore, suggested that these are the earliest detectable morphological abnormalities in the pre-neoplastic urothelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00431388
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  • 11
    Electronic Resource
    Electronic Resource
    Ultrastructure of a virilizing ovarian Leydig-cell-tumor (1982)
    Springer
    Virchows Archiv 397 (1982), S. 17-27 
    Details
    ISSN: 1432-2307
    Keywords: Ovarian tumor ; Hilus cell tumor ; Leydig cell tumor ; Virilism ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of virilizing ovarian hilus cell tumor (Leydig-cell tumor) in a 37 year old female was studied by light and electron microscopy. The ultrastructural features of this rare and almost allways benign tumor are compared with those reported in the literature and with findings in normal and neoplastic interstitial cells of the testis. Tubulovesicular hyperplasia and formation of whorl structures of the endoplasmatic reticulum together with the presence of exocytosis vesicles on the cell surface may be the morphological manifestation of endocrine activity of the tumor. The identity of ultrastructural and optical diffraction characteristics of the crystal inclusions in both cells (hilar and testicular interstitial) favours the assumption of an homology of both cells and their neoplasms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00430890
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  • 12
    Electronic Resource
    Electronic Resource
    Synovial sarcoma arising in an anatomical bursa (1982)
    Springer
    Virchows Archiv 397 (1982), S. 93-101 
    Details
    ISSN: 1432-2307
    Keywords: Biphasic synovial sarcoma ; Semitendinosus bursa ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In previous studies, the origin of synovial sarcoma directly from synovium has not been satisfactorily established. This case report describes the light and electron microscopic features of a biphasic synovial sarcoma occurring within the popliteal fossa. At surgery, a cystic mass was identified in relationship to the semitendinosus tendon at the anatomical site of the semitendinosus bursa. The tumour originated from the inner surface of the bursa as multiple papillary projections with no evidence of extension beyond the capsule of the bursa. Portions of the synovial surface were hyperplastic but otherwise normal. The findings indicate that biphasic synovial sarcoma can arise directly from synovium and support the hypothesis of a mesenchymal histogenesis for this tumour.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00430896
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  • 13
    Electronic Resource
    Electronic Resource
    Tumor of mesonephric origin in a diverticulum of the urethra (1982)
    Springer
    Virchows Archiv 397 (1982), S. 335-345 
    Details
    ISSN: 1432-2307
    Keywords: Bladder neoplasm ; Mesonephric origin ; Urethral diverticulum ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of a rare tumor arising in a diverticulum of the urethra was studied. Light microscopy revealed the typical structures of mesonephric tumor with obvious infiltration of the muscularis. Electron microscopic appearance indicated that the tumor cells were immature and not totally characteristic of any tissue of origin. Apart from appearances suggesting rapid growth, cellular inclusions of various appearance were found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00496574
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  • 14
    Electronic Resource
    Electronic Resource
    Observations on the ultrastructure of human urothelium: The response of normal bladder of elderly subjects to hyperthermia (1982)
    Springer
    Urological research 10 (1982), S. 227-237 
    Details
    ISSN: 1434-0879
    Keywords: Human ; Bladder urothelium ; Electron microscopy ; Hyperthermia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electron microscopic study of normal bladder urothelium of elderly subjects treated by hyperthermic perfusions has shown that the tissue responds, sooner or later, in every instance by desquamation. There is no evidence of cell death prior to desquamation although various organelles undergo structural alterations. Mitochondria are especially prone to suffer varying degrees of damage. A short heat shock has revealed differences in the initial response of the thick and thin regions of bladder urothelium known to occur in elderly subjects. After a long, fractionated treatment, regeneration is evident within 3 daysof the end of treatment, and follow-up biopsies have revealed a hyperplastic urothelium within 10 to 12 weeks. The constituent cells show signs of cytodifferentiation at this time but it remains unknown when an ultrastructurally normal urothelium with characteristic cell layers will be restored. The various treatments in this study suggest that the stem cells in the epithelium are unaffected by the levels of hyperthermia employed and that their unimpaired proliferative capacity ensures regeneration of the urothelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00255928
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  • 15
    Electronic Resource
    Electronic Resource
    The effect of tetraphenylporphinesulfonate (TPPS) on muscle end-plates in mice (1982)
    Springer
    Acta neuropathologica 56 (1982), S. 201-206 
    Details
    ISSN: 1432-0533
    Keywords: Muscle end-plates ; Porphyric neuropathy ; Electron microscopy ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Motor end-plates were studied in mice at various intervals after a single injection of a synthetic porphyrin, tetraphenylporphinesulfonate (TPPS). Ultrastructurally, excess accumulation of neurofilaments constituted the earliest abnormality. These were followed by atrophy of many nerve terminals and their separation from the postsynaptic area by interposed separation from the postsynaptic area by interposed Schwann cells. Five to 8 months after the injection some postsynaptic areas showed denervation and atrophy. These progressive changes in the nerve terminals were accompanied by secondary changes in the subneural apparatus. Morphometric analysis revealed marked atrophy of the end-plates and significant swelling of preterminal axons. The present findings are suggestive of partial denervation of muscle, occurring after the injection of a synthetic porphyrin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690636
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  • 16
    Electronic Resource
    Electronic Resource
    Intra-astrocytic glycogen granules and corpora amylacea stain positively for polyglucosans: A cytochemical contribution on the fine structural polymorphism of particulate polysaccharides (1982)
    Springer
    Acta neuropathologica 57 (1982), S. 99-102 
    Details
    ISSN: 1432-0533
    Keywords: Cytochemistry ; Electron microscopy ; Polyglucosan bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A cytochemical procedure for polysaccharides was carried out on a brain biopsy specimen, the thin-section study of which had shown excess glucogen granules and the corpora amylacea variety of polyglucosan bodies. Both granules and amyloid bodies were stained positively in contrast to the remaining structures of the brain tissue which remained unstained. This demonstrates that β-granules as well as filamentous and amorphous components of amyloid bodies are just different aspects of the polysaccharide molecule. Up to now the same kind of cytochemical evidence has been supplied for Lafora bodies of human material and Lafora-like bodies of rat material. The present study on corpora amylacea of human material shows that amyloid. Lafora, and Lafora-like bodies all behave the same way when stained for polysaccharides.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685376
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  • 17
    Electronic Resource
    Electronic Resource
    Spongiform-like changes in Alzheimer's disease (1982)
    Springer
    Acta neuropathologica 56 (1982), S. 146-150 
    Details
    ISSN: 1432-0533
    Keywords: Alzheimer's disease ; Creutzfeldt-Jakob disease ; Spongiform changes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural study of the cortex of four patients with sporadic or familial AD, of two agematched controls without dementia, and of one normal pressure hydrocephalus, revealed in all the cases in the neuropil only occasional vacuoles which had a morphology similar to those observed in CJD. The degree of spongiform-like changes was, however, far less prominent than in CJD and considered mild in all the cases examined. Moreover, curled fragments of membranes within the vacuoles were not observed. It is suggested that the mild vacuolization of the neuropil occasionally observed in cortical biopsies of AD is a non-specific finding and cannot be considered a neuropathologic link between AD and CJD.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690586
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  • 18
    Electronic Resource
    Electronic Resource
    Central neurocytoma (1982)
    Springer
    Acta neuropathologica 56 (1982), S. 151-156 
    Details
    ISSN: 1432-0533
    Keywords: Central neuronal tumor ; Third ventricle tumor ; Synapses ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The authors report two cases of a rare tumor in adults which were inserted on the fornix and caused a frontal syndrome. By light microscopy, the tumors, highly calcified, were composed of small clear cells forming dense areas in a patchy fibrillary stroma. Electron microscopy revealed a striking neuronal differentiation with numerous synapses. These tumors, for which the term neurocytomas was proposed, were compared with the other CNS neuronal tumors described in the literature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690587
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  • 19
    Electronic Resource
    Electronic Resource
    Oculopharyngeal dystrophy: Ultrastructure of muscles distant from the primary myopathy (1982)
    Springer
    Acta neuropathologica 57 (1982), S. 7-12 
    Details
    ISSN: 1432-0533
    Keywords: Oculopharyngeal muscular dystrophy ; Electron microscopy ; Pectoral and psoas muscles ; Myofibrillar degeneration ; A band fragmentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The pectoral and psoas muscles from a 72-year-old man afflicted with oculopharyngeal muscular dystrophy were processed at autopsy for electron microscopy. The ultrastructural analyses of the pectoral muscle showed myofibrils which exhibited Z line streaming and a general breakdown in the organization of the sarcomere. In addition, some of the myofibrils displayed sites of degeneration at the center of the A band. The changes in the psoas muscles which are distant from the primary myopathic loci of oculopharyngeal muscular dystrophy were more extensive than that seen in the pectoral muscle. Control tissues showed intact myofibrils and little postmortem alteration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688872
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  • 20
    Electronic Resource
    Electronic Resource
    Zur Feinstruktur der Nervenendigungen in den Muskelspindeln des M. lumbricalis der Ratte nach Durchschneidung des Nerven (1982)
    Springer
    Acta neuropathologica 57 (1982), S. 23-36 
    Details
    ISSN: 1432-0533
    Keywords: Muscle spindle ; Electron microscopy ; Nerve endings ; Denervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The nerve endings in muscle spindles from lumbricalis muscles of the hindpaw of the rat were studied by electron microscopy from 10 h to 7 days after section of the sciatic nerve. No sensory endings were found after 5 days and no motor endings after 3 days. Early changes in sensory endings included accumulation of lamellar bodies, mitochondrial swelling or shrinkage, an edematous appearance of the cytoplasm and disruption of membranes. The predominant way of removal was phagocytosis by activated mesenchymal cells; other endings were incorporated into the sarcoplasm as electrondense bodies. Early changes in motor endings included aggregation or swelling of synaptic vesicles, swelling or shrinkage of mitochondria, edematous change of the cytoplasm and disruption of membranes. The predominant way of removal was incorporation into the cytoplasm of adjacent Schwann cells and degradation to phagolysosomes. Sites of removed sensory endings could be identified by basement membrane reduplication, while the intact subsynaptic apparatus of removed motor endings was either loosely covered by Schwann cell processes, or by fibrillar material, or appeared empty. The differences in the removal of motor and sensory endings are explained by the differences in their anatomic structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688874
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  • 21
    Electronic Resource
    Electronic Resource
    An electron-microscopic study of the brain of the fruit fly,Drosophila melanogaster, exposed to high-LET krypton (84Kr) particle radiation (1982)
    Springer
    Acta neuropathologica 57 (1982), S. 37-44 
    Details
    ISSN: 1432-0533
    Keywords: Radiation effects ; Nervous system ; Drosophila melanogaster ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fruit flies (Drosophila melanogaster) were exposed to high-LET krypton (84Kr) ions at low (4.2 rad) and high (1,584 rad) doses and killed to assess acute (36 h post-exposure) and late (35 days post-exposure) effects in the brain by means of electron microscopy. The main findings were: (a) glycogen granules appeared in the neuroglial compartment 36 h after exposure to either dose and were no longer present in flies killed 35 days later, (b) neuronal alterations (swelling and membrane disruption) were observed 35 days after exposure to both doses, (c) changes in the neuroglia (electron-dense masses of concentrically arranged membranous structures) were seen 35 days after exposure. The data are discussed in relation to previous research in the fruit fly using argon (40Ar) charged particles and to other radiation studies performed in the mammalian brain with the view of using the insect brain as a model for detailed study of radiation effects on neurons, neuroglia, and the neuron-neuroglia unit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688875
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  • 22
    Electronic Resource
    Electronic Resource
    Hirano bodies in myelinated fibers of hepatic encephalopathy (1982)
    Springer
    Acta neuropathologica 58 (1982), S. 307-310 
    Details
    ISSN: 1432-0533
    Keywords: Hirano body ; Hepatic encephalopathy ; Oligodendroglia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Inclusions, essentially identical to Hirano bodies, were observed in the substantia nigra, dentate nuclei, and frontal lobes in three autopsy cases of hepatic encephalopathy. Similar inclusions were not observed in these areas in nine controls. The inclusions were mainly seen in the inner loops of the myelinated fibers, between the myelin lamellae, and among degenerated myelin sheaths. The same inclusions were rarely observed in postsynaptic terminals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688615
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  • 23
    Electronic Resource
    Electronic Resource
    The permeability alteration of brain and spinal cord vasculature to horseradish peroxidase during experimental decompression sickness as compared to the alteration in permeability induced by hyperosmolar solution (1982)
    Springer
    Acta neuropathologica 57 (1982), S. 179-187 
    Details
    ISSN: 1432-0533
    Keywords: Decompression sickness ; Hypertonic solutions ; Blood-brain barrier ; Blood-spinal cord barrier ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The permeability of microvasculature in the cerebral cortex, neostriatum, and spinal cord to i. v. injected horseradish peroxidase (HRP) has been investigated in rats following experimental compression to 6.1 bars (abs.) air for 90 min, and subsequent decompression to the ambient pressure in 1 min. For comparison, 1 ml of 2.0 M urea was injected into the right common carotid artery of rats during 15 s. After exposure to compression-decompression, under the light microscope focal leaky areas were found in all the regions examined. The leakage was most prominent in the grey matter of the spinal cord, and the cerebral cortex. In decompressed rats, arterioles were most often the site of peroxidase extravasation, whereas extravasation of HRP was less frequently displayed by capillaries and venules. In urea-treated rats, capillaries and venules frequently displayed extravasation of HRP as well. Parenchymal cells accumulated the trace adjacent to the leaky areas. Under the electron microscope, the extravasation of HRP was associated with peroxidase-containing pleomorphic vesicular structures in the endothelium, both in decompressed and urea-injected rats. Moreover, in contrast to decompressed rats, the junctions between endothelial cells were penetrated by the trace in urea-treated rats. Accordingly, the results indicate that during decompression sickness the pathway for the extravasation of proteins is through vesicular transfer, whereas the injection of hyperosmolar urea induces extravasation, both through vesicular transfer and junctions between the endothelial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685387
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  • 24
    Electronic Resource
    Electronic Resource
    Muscle fiber type morphology and distribution in paraplegic patients with traumatic cord lesion (1982)
    Springer
    Acta neuropathologica 57 (1982), S. 243-248 
    Details
    ISSN: 1432-0533
    Keywords: Skeletal muscle ; Paraplegia ; Complete spinal cord lesion ; Histopatology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Biopsies of the rectus femoris muscle of 22 paraplegic patients with complete acute spinal cord transection due to trauma were taken for enzyme-histochemical and electron-microscopic studies in successive stages starting from the occurrence of the accident (1–17 months). Ingravescent muscular atrophy was demonstrated with a progressive decrease in the fiber diameter and changes in the fiber type distribution with predominant type II atrophy in the first stage and type I atrophy in the later stage of the cord transection. Muscular “neurogenic” changes, such as angular dark atrophic fibers, targetoid fibers, and type predominance are frequently observed. Myopathic alterations are observed in a low percentage in the later stages of the lesion. The ultrastructural findings are characterized by myofibrillar alterations and by dilatation and proliferative phenomena of the sarcoplasmic reticulum and T-system. There are ingravescent accumulation of lipid, interstitial fibrosis and microcirculatory alterations. The possible mechanism of “central” muscle atrophy is reviewed and discussed with reference to the morphological findings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00692178
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  • 25
    Electronic Resource
    Electronic Resource
    The ultrastructural development of distal nephron segments in the human fetal kidney (1982)
    Springer
    Anatomy and embryology 164 (1982), S. 19-41 
    Details
    ISSN: 1432-0568
    Keywords: Human kidney ; Nephron development ; Distal segments ; Electron microscopy ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural development of the human distal nephron was studied in fetuses 14–18 weeks of gestational age. The three-dimensional course of the nephrons was traced in serial semi-thin sections. Single semi-thin sections containing defined distal nephron segments were then reembedded, thin-sectioned and analyzed by electron microscopy. In stage I (renal vesicle) and stage II (S-shaped body) epithelial cells were essentially similar in ultrastructure. In stage III there were only minor variations in cell ultrastructure between distal nephron segments, but distinct differences were observed between proximal and distal tubule cells, the former being the most differentiated. The segments which are present in nephrons of adult kidneys could be identified in stage IV and some ultrastructural differences recognized between the cells. However, the amplification of the baso-lateral membrane, which is prominent in iontransporting mature distal segments, was almost absent and the baso-lateral membrane area per unit tubule length was similar in all distal segments. Intercalated cells were present towards the end of the distal convoluted and in the connecting tubule in stage IV but the ampulla of the collecting tubule was composed of cells with a uniform ultrastructure. Cell ultrastructure varied again to some extent in the collecting tubule. The present observations demonstrate that distal nephron segments in the human kidney are structurally undifferentiated in the early fetal development and suggest that they only to a limited extent are capable of modifying the composition of the tubular fluid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00301876
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  • 26
    Electronic Resource
    Electronic Resource
    Immunoglobulin production and secretion in bence jones protein myeloma and “nonsecretory” myeloma (1982)
    Springer
    Annals of hematology 45 (1982), S. 121-129 
    Details
    ISSN: 1432-0584
    Keywords: Multiple myeloma ; Immunoglobulin ; Electron microscopy ; Fluorescent antibody technique
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using our electron microscopic method for polysome analysis and an immunofluorescent technique we studied Ig production and secretion by tumor cells in seven BJP myeloma patients and seven “nonsecretory” myeloma patients. In BJP myeloma Ig production and secretion is of three types: Type 1, only L-chains are synthesized and secreted; Type 2, the myeloma cells show fluorescence for H-chains, but upon polysome analysis there is no peak at polysomes corresponding to H-chain production; Type 3, the myeloma cells show fluorescence for H-chains, and polysome analysis shows two peaks corresponding to L- and H-chain production. Polysome analysis of “nonsecretory” myelomas show the presence of only very few membrane-bound polysomes and their distribution curves are entirely different from those of “ordinary” myeloma. Furthermore, the distribution patterns vary among seven cases. Results obtained by polysome analysis and immunofluorescent technique suggest that the “nonsecretory” myeloma could be divided into several subtypes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319940
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  • 27
    Electronic Resource
    Electronic Resource
    Tubular aggregates in skeletal muscle of chronic alcoholic patients (1982)
    Springer
    Acta neuropathologica 56 (1982), S. 250-254 
    Details
    ISSN: 1432-0533
    Keywords: Skeletal muscle ; Chronic alcoholism ; Tubular aggregates ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The presence of tubular aggregates (TA) in type II muscle fibers in two of 20 alcoholic patients with chronic liver disease, and with no apparent neuromuscular disorder, is reported. The localization, histochemical reactions, and ultrastructural features of the TA are similar to those previously described in other conditions. In one of the two cases TA were demonstrated by E/M observations only and not by histochemistry. No correlations were found between the biochemical changes and the presence of tubular aggregates. We believe that TA are long-standing structures since the muscle biopsies were performed 12 and 13 days after the ingestion of alcohol had been discontinued. They may represent a non-specific response of the sarcoplasmic reticulum to compensate for the deficient calcium uptake reported in alcoholic patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691255
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  • 28
    Electronic Resource
    Electronic Resource
    Cerebrovascular pathogenesis in the telencephalon of the loop-tail mouse: A transmission electron-microscopic study (1982)
    Springer
    Acta neuropathologica 58 (1982), S. 177-182 
    Details
    ISSN: 1432-0533
    Keywords: Cerebral vessels ; Telencephalon ; Looptail mutant mouse ; Pathogenesis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cerebral capillaries in the telencephalon of normal (+/+;Lp/+)_and abnormal (Lp/Lp) loop-tail mutant mice were studied chronologically by means of electron microscopy at stages ranging from 15 through 18 days of gestation. In the abnormal tissue, neural rosettes were common, and cellular material and red blood cells were often contained within the lumen of the rosettes. The endothelial cells of telencephalic blood vessels in the abnormal brains showed a persistence of cellular projections, subluminal vacuoles, and swollen mitochondria beyond the stage when these features ordinarily disappear in normal embryonic cerebral vessels. The endothelial cells in the abnormal brains also failed to become fully invested with pericytes, and red blood cells gradually infiltrated the neural tissue, particularly in subependymal regions, at 16–18 days of gestation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690798
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  • 29
    Electronic Resource
    Electronic Resource
    Fine structure of merkel cells after PUVA treatment (1982)
    Springer
    Archives of dermatological research 274 (1982), S. 373-375 
    Details
    ISSN: 1432-069X
    Keywords: Merkel cell ; PUVA ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00403744
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  • 30
    Electronic Resource
    Electronic Resource
    Ultrastructural evidence for inhibition of chitin synthesis by nikkomycin (1982)
    Springer
    Development genes and evolution 191 (1982), S. 205-207 
    Details
    ISSN: 1432-041X
    Keywords: Chitin inhibition ; Nikkomycin ; Cuticle ; Electron microscopy ; Epilachna varivestis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The nucleoside antibiotic nikkomycin has proved to be an effective inhibitor of chitin synthesis in the Mexican bean beetleEpilachna varivestis. Ultrastructural investigations show defects in the procuticular area after nikkomycin application which suggest the complete absence of chitin. A cuticle like this is inflexible and too brittle to satisfy its normal function as an exoskeleton. The individuals are not able to free themselves from the exuvia and finally die. Therefore nikkomycin seems to be a potential insecticide with high specifity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848337
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  • 31
    Electronic Resource
    Electronic Resource
    Long-term study of liver damage following subcutaneous injection of airborne particle extracts and polycyclic aromatic hydrocarbon fractions (1982)
    Springer
    International archives of occupational and environmental health 49 (1982), S. 305-314 
    Details
    ISSN: 1432-1246
    Keywords: Polycyclic aromatic hydrocarbon ; Liver ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Female NMRI mice aged 9–12 weeks were each given a single subcutaneous injection of 0.5 ml of a suspension containing either the total extracts or the polycyclic aromatic hydrocarbon (PAH) fraction of airborne particles. Both the total extracts and PAH fractions contain 3 Vg benzopyrene. After about 15 months the livers were removed from the animals, which had by that time developed tumors at the injection site, and were subjected to ectronmicroscopical study. The essential alterations were observed in the nucleoli and the cell nuclei, which had greatly proliferated and exhibited irregular nuclear membranes. Advanced fibrosis was observed in central liver specimens of all groups. Marked alterations were also observed in the mitochondria and the mitochondria) cristae as well as in the bile canaliculi. Intracytoplasmic glycogen usually occurred densely clustered along the periphery of the cell. It may be concluded from the observations that both the total extract of atmospheric suspended particulate matter and the PAH fraction cause hematogenic damage to the liver following subcutaneous injection, a finding which cannot be interpreted as metastatic carcinoma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00377939
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  • 32
    Electronic Resource
    Electronic Resource
    Biologic characterization of human bone tumors I. Ewing's sarcoma (1982)
    Springer
    Journal of cancer research and clinical oncology 104 (1982), S. 171-180 
    Details
    ISSN: 1432-1335
    Keywords: Ewing's sarcoma ; Type IV collagen ; Factor-VIII-associated protein ; Endothelial differentiation ; Electron microscopy ; Immunofluorescence microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Six cases of Ewing's sarcoma were investigated by electron and immunofluorescence microscopy. A layer of basement membrane-like deposits was found between typical principal and secondary tumor cells. To clarify the nature of these ultrastructural deposits, antibodies against collagen type IV were applied to frozen sections of corresponding tumor tissue. This reaction revealed type IV collagen as a regular component of basement membranes in nonneoplastic tumor capillaries, but it was equally able to localize collagen type IV between single tumor cells in capillary-free areas. With the same method, factor-VIII-associated protein, predominantly found in endothelial cells, could be demonstrated in some tumor cells. These results demonstrate that, in addition to anaplastic cells, some tumor cells are found in Ewing's sarcoma that share certain differentiating features with the endothelial cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00402065
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  • 33
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    Electronic Resource
    Ultrastructural pathology of human lymphocytes in lysosomal disorders: a contribution to their morphological diagnosis (1982)
    Springer
    European journal of pediatrics 138 (1982), S. 179-185 
    Details
    ISSN: 1432-1076
    Keywords: Lymphocytes ; Metabolic disorders ; Inclusions ; Lysosomes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Ultrastructural examination of peripheral lymphocytes was performed in 28 cases of various lysosomal diseases, including infantile, late infantile and juvenile neuronal ceroid-lipofuscinoses (NCL), mucopolysaccharidoses (MPS), juvenile and adult metachromatic leukodystrophies (MLD), GM1-gangliosidosis, one patient with presumed mucolipidosis type IV, mucolipidosis type III, and glycogenosis type II. Based on our own observations on the ultrastructure of lymphocytes in lysosomal disorders, our results may be divided into the following 3 groups: 1. pathological findings with specific inclusions: each type of NCL, presumed mucolipidosis type IV, glycogenosis type II; 2. pathological findings with vacuoles: types I-H, II, III-A and III-B, IV, VI-A and VI-B of MPS, GM1-gangliosidosis; 3. apparently no pathological findings: juvenile and adult MLD, mucolipidosis type III, GM2-gangliosidosis, Gaucher disease. These results led us to conclude that morphological investigations utilizing lymphocytes do not always offer sufficient diagnostic information although easy accessibility favors diagnostic ultrastructural studies of lymphocytes. Such morphological studies should be supplemented by diagnostic biochemical methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00441150
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  • 34
    Electronic Resource
    Electronic Resource
    Comparative studies onChlorella cell walls: Induction of protoplast formation (1982)
    Springer
    Archives of microbiology 132 (1982), S. 10-13 
    Details
    ISSN: 1432-072X
    Keywords: Calcofluor White ; Cell wall structure ; Chlorella ; Electron microscopy ; Protoplast ; Ruthenium Red
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Among 12 strains ofChlorella ellipsoidea, C. vulgaris, andC. saccharophila tested, 4 strains (1,C. ellpsoidea; 2,C. vulgaris; 1,C. saccharophila) formed osmotically labile protoplasts after treatment with mixtures of polysaccharide degrading enzymes. The relationship between enzymatical digestibility and structure or composition ofChlorella cell walls were studied by electron microscopy and staining techniques with some specific dyes. The cell wall structures of the 12Chlorella strains were grouped into three types: (1) with a trilaminar outer layer, (2) with a thin outer monolayer, and (3) without an outer layer. Protoplasts were formed only from the strains with a cell wall of Type 2. In the strains with a cell wall of Type 1, the outer layer protected the inner major microfibrillar layer against enzymatic digestion. The cell wall of Type 3 was totally resistant to the enzymes; the chemical composition of the cell wall would be somewhat different from that of other types.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690809
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  • 35
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    Electronic Resource
    Thylakoid centers: Structures associated with the cyanobacterial photosynthetic membrane system (1982)
    Springer
    Archives of microbiology 133 (1982), S. 97-99 
    Details
    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Thylakoid centers ; Photosynthetic membranes/thylakoids ; Membranes ; Membrane biogenesis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An ultrastructural study of four cyanobacteria (Anabaena cylindrica, Dermocarpa violaceae, Gleocapsa alpicola, Pleurocapsa minor) indicates the presence of previously undescribed thylakoid centers from which photosynthetic membranes (thylakoids) radiate. These peripherally located thylakoid centers are cylinders 30 nm wide by 320 nm long, consisting of globular subunits oriented in nonparallel stacked arrays. Thylakoids are attached to the outer surface of the cylinder along its longitudinal axis. Thylakoid centers appear to be functionally significant due to their structure, location and thylakoid association.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00413518
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  • 36
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    Electronic Resource
    Cell wall degradation ofStaphylococcus aureus by lysozyme (1982)
    Springer
    Archives of microbiology 131 (1982), S. 116-123 
    Details
    ISSN: 1432-072X
    Keywords: Cell wall ; Wall degradation ; Lysozyme ; Autolysines ; Electron microscopy ; Staphylococcus aureus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In contrast to former findings lysozyme was able to attack the cell walls ofStaphylococcus aureus under acid conditions. However, experiments with14C-labelled cell walls and ribonuclease indicated that, under these conditions, lysozyme acted less as an muralytic enzyme but more as an activator of pre-existing autolytic wall enzymes. Electron microscopic studies showed that under these acid conditions the cell walls were degraded by a new mechanism (i.e. “attack from the inside”). This attack on the cell wall started asymmetrically within the region of the cross wall and induced the formation of periodically arranged lytic sites between the cytoplasmic membrane and the cell wall proper. Subsequently, a gap between the cell wall and the cytoplasmic membrane resulted and large cell wall segments became detached and suspended in the medium. The sequence of lytic events corresponded to processes known to take place during wall regeneration and wall formation. In the final stage of lysozyme action at pH 5 no cell debris but “stabilized protoplasts” were to be seen without detectable alterations of the primary shape of the cells. At the same time long extended ribbon-like structures appeared outside the bacteria. The origin as well as the chemical nature of this material is discussed. Furthermore, immunological implications are considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01053992
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  • 37
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    Electronic Resource
    Human osteogenic sarcoma (1982)
    Springer
    International orthopaedics 6 (1982), S. 171-179 
    Details
    ISSN: 1432-5195
    Keywords: Osteosarcoma ; Electron microscopy ; Acid phosphate ; Alkaline phosphate ; Bone tumour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé La morphologie de 26 sarcomes ostéogéniques a été étudiée par microscopie électronique et la localisation des phosphatases acide et alcaline a pu être précisée au niveau ultrastructural. Quatre différents types de cellules ont été mis en évidence dans les tumeurs: cellules d'aspect ostéoblastique, fibroblastique et chondroblastique, ainsi que des cellules géantes multinuclées. Les cellules d'aspect ostéoblastique étaient présentes dans presque toutes les tumeurs étudiées. Une activité phosphatasique acide a été trouvée dans les lysosomes de toutes les cellules étudiées. Une activité phosphatasique alcaline a été observée dans — ou sur — la membrane plasmatique et dans les vésicules associées des cellules d'aspect ostéoblastique et fibroblastique ainsi que des cellules géantes. L'abondance des produits de réaction de la phosphatase alcaline contrastant avec une faible activité phosphatasique acide est en accord avec la nature de cette tumeur ostéogénique. Les résultats de l'étude histochimique ont aidé à comprendre la pathobiologie des différentes cellules qui constituent les sarcomes ostéogéniques.
    Notes: Summary The morphology of 26 cases of osteogenic sarcoma was studied using electron microscopic techniques, and the localization of acid and alkaline phosphatase activity at the ultrastructural level elucidated. Four different cells were present in the tumours: osteoblast-like, fibroblast-like, chondroblast-like, and multinucleated giant cells. The osteoblast-like cell was present in most of the tumours studied. Acid phosphatase activity was present in lysosome-like structures of almost all the cell-types studied. Alkaline phosphatase activity was noted in or on the plasma membranes and associated vesicles of osteoblast-like, fibroblast-like, and multinucleated giant cells. The abundant reaction product deposition of alkaline phosphatase as compared with the lower acid phosphatase activity is in agreement with the nature of this bone-forming tumour. The results of the histochemical studies have added to the understanding of the pathobiology of the different cells composing osteogenic sarcomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00267727
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  • 38
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    Electronic Resource
    Sensory organs inIps typographus (Insecta: Coleoptera) — Fine structure of antennal sensilla (1982)
    Springer
    Protoplasma 111 (1982), S. 206-214 
    Details
    ISSN: 1615-6102
    Keywords: Bark beetle ; Sensilla ; Chemoreceptors ; Mechanoreceptors ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The antennal sensilla inI. typographus are almost exclusively confined to the flattened terminal flagellar segment. The sensillar types have distinct distribution patterns in the three areas where they are found. Judging from the ultrastructural characteristics the following functions can be assigned to the sensillar types: chemoreception, single-walled and double-walled sensilla; chemoreception/mechanoreception, terminal-pore sensillum. Moreover there are two types of mechanoreceptors, one of which is connected to a bristle, whereas the other terminates within the cuticle of the flagellar segment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01281968
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  • 39
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    Electronic Resource
    Morphologische Untersuchungen zur Toxizität der Ethacrynsäure an der Prominentia spiralis (1982)
    Springer
    European archives of oto-rhino-laryngology and head & neck 236 (1982), S. 217-228 
    Details
    ISSN: 1434-4726
    Keywords: Ethacrynic acid ; Spiral prominence ; Electron microscopy ; Ethacrynsäure ; Prominentia spiralis cochleae ; Elek tronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Nach einmaliger intravenöser Ethacrynsäure-Applikation (40 mg/kg Körpergewicht) wurden die ultastrukturellen Veränderungen in der Prominentia spiralis der Meerschweinchenschnecke nach Einwirkungszeiten zwischen 5 und 90 min untersucht. Nach einer initialen Schwellung der den Endolymphraum begrenzenden Epithelzellen entwickelte sich ein interzelluläres Ödem und eine ausgeprägte Schrumpfung der das Vas prominens umgebenden Stromazellen mit nachfolgender Erweiterung des Perivascularraumes. Während die Veränderungen in der Stria vascularis und der Prominentia spiralis im zeitlichen Verlauf sich weitgehend identisch entwickelten, setzte die Rückbildung zur normalen Ultrastruktur in der Prominentia spiralis früher ein.
    Notes: Summary Ultrastructural changes in the guinea pig spiral prominence were studied at various times after a single intravenous injection of ethacrynic acid (40 mg/kg body-weight). Initial swelling of endolymph-facing epithelial cells was followed by dilatation of the intercellular spaces and marked shrinkage of the stroma cells surrounding the spiral prominence vessel. While the changes in the stria vascularis and the spiral prominence progressed at about the same pace, the regression to normal ultrastructure set in earlier in the spiral prominence.
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    URL: http://dx.doi.org/10.1007/BF00454213
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    Electronic Resource
    Electronic Resource
    Cells and intercellular contacts in glomeruli and tubules of the frog kidney (1982)
    Springer
    Cell & tissue research 226 (1982), S. 589-608 
    Details
    ISSN: 1432-0878
    Keywords: Kidney (frog) ; Glomerulus ; Nephron ; Tight junctions ; Freeze-fracturing ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By the use of thin sections and freeze-fracture replicas the glomerular and tubular structures of the kidney of the frog (Rana esculenta) were studied with special reference to intercellular junctions. In the glomerulus the filtration barrier is of very variable thickness, and frequent tight and gap junctional contacts occur between podocyte processes. Although structurally less elaborate, the proximal tubule resembles its mammalian counterpart. In the initial part the tight junctions are relatively shallow but become very broad in the mid and distal portions of the proximal tubule. The proximal tubular cells are extensively linked by gap junctions. In some animals the shapes of the cells in the proximal and distal portions of the proximal tubule were markedly different. The distal tubule consists of two segments which differ mainly in the pattern of interdigitations and the structure of the zonulae occludentes. Similarities with the tight junctional morphology of the mammalian distal tubule are striking. In the first part of the distal tubule (diluting segment) a narrow band of parallel tight junctions is found closely resembling that found in the mammalian straight distal tubule; in the more distal part of the distal tubule, however, a broad band of anastomosing tight junctional strands exists, like the zonula occludens of the mammalian convoluted distal tubule. The connecting tubule displays cellular dimorphism: its wall contains a mixture of light and dark (flask) cells. The luminal and basolateral membranes of the flask cells are covered with numerous rod-shaped particles. The tight junctions of the connecting tubule are broad and increase in depth and number of strands along its length; they are typical of a very tight epithelium. In spite of several dissimilarities with phylogenetically younger kidneys our findings suggest that many structural principles of the mammalian kidney are also represented in the kidneys of amphibians. The structural-functional relationships are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214787
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    Electronic Resource
    Ultrastructure of endocrine cells in the stomach of two teleost fish Perca fluviatilis L. and Ameiurus nebulosus L. (1982)
    Springer
    Cell & tissue research 221 (1982), S. 657-678 
    Details
    ISSN: 1432-0878
    Keywords: Stomach (Teleost) ; Endocrine cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the gastric mucosa of two teleost species, the perch (Perca fluviatilis) and the catfish (Ameiurus nebulosus) three endocrine cell types were found, located predominantly between the mucoid cells of the gastric mucosa. A fourth cell type is present in the gastric glands of catfish. Each cell type was defined by its characteristic secretory granules. Type-I cells were predominant in both fish. These cells contained round or oval granules with a pleomorphic core. The average diameter of granules was 400 nm for the perch and 270 nm for the catfish. Type-II cells of both species displayed small, highly osmiophilic granules about 100 nm in diameter. The secretory granules of type-III cells (260 nm in the perch and 190 nm in the catfish) were round or slightly oval in shape and were filled with a finely particulate electron-dense material. Type-IV cells of the catfish were found in the gastric glands only. Their cytoplasm was filled with homogeneous, moderately electron-dense granules averaging 340 nm in diameter. The physiological significance of these different morphological types of gastric endocrine cells requires further investigation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215709
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  • 42
    Electronic Resource
    Electronic Resource
    Apical region of the crayfish retinula (1982)
    Springer
    Cell & tissue research 222 (1982), S. 409-415 
    Details
    ISSN: 1432-0878
    Keywords: Crustacean compound eye ; Eighth retinular cell ; Crystalline tract ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The base of the crystalline tract, the distal part of the eighth retinular cell and its rhabdomer constitute a structural unit in the apical region of the retinula of Astacus fluviatilis and A. leptodactylus, shielded from the blood by a special covering cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213221
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  • 43
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    Electronic Resource
    Electron-microscopic localization of A2B5 cell surface antigen in monolayer cultures of murine cerebellum and retina (1982)
    Springer
    Cell & tissue research 224 (1982), S. 637-645 
    Details
    ISSN: 1432-0878
    Keywords: Cell surface antigen ; Neurons ; Glia ; Electron microscopy ; Immunoperoxidase ; Monoclonal antibody
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immuno-electron microscopy was performed on live, cultured, early postnatal cerebellar and retinal cells of the mouse to identify A2B5 antigenbearing elements. In cerebellar cultures, granule cells, some immature oligodendroglia, and astroblasts express A2B5 antigen on their cell surfaces. The typical features of astroblasts include large cisternae of the endoplasmic reticulum and a mixed population of intermediate-sized filaments and microtubules. Immature oligodendroglia cells express the antigen on their cell bodies and on procecesses filled with cytoplasm. Cytoplasm-free membranous whorls, however, are devoid of A2B5 antigen, but not of 0 or NS-1 antigens. In retinal cultures, A2B5 antigen is observed on differentiating neurons with the exception of photoreceptor cells as identified by ribbon synapses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213758
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  • 44
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    Electronic Resource
    Survival of Pacinian corpuscles after denervation in adult rats (1982)
    Springer
    Cell & tissue research 224 (1982), S. 673-683 
    Details
    ISSN: 1432-0878
    Keywords: Pacinian corpuscles, rat ; Denervation ; Sensory terminals ; Nerve degeneration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of Pacinian corpuscles located on the crural interosseous membrane was studied in adult rats 6 h to 10 months after transection of the right sciatic nerve. Axon terminals degenerated one day after transection and were engulfed and resorbed by cells of the inner core within one week. The axial space left after removal of the axonal debris was closed by the lamellae of the inner core. The main structural features of the inner core and capsule remained preserved after denervation throughout the period of study. The denervated inner cores, however, became atrophic 10 months after neurotomy, their mean diameter being reduced by 17.5% compared with that of contralateral control corpuscles. The number of capsular lamellae was unaltered, and perineurial pathways of the peripheral nerve stump remained preserved. Schwann cells proliferated and formed Büngner bands during the first month after denervation, but retracted their processes and became atrophic at later stages after neurotomy. Survival of Pacinian corpuscles after long-term denervation in adult rats is in contrast to their rapid degeneration within several days after nerve section in neonates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213762
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  • 45
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    Electronic Resource
    Close apposition of muscle cells in the longitudinal bands of the body wall of a holothurian, Isostichopus badionotus (1982)
    Springer
    Cell & tissue research 227 (1982), S. 465-473 
    Details
    ISSN: 1432-0878
    Keywords: Electron microscopy ; Junctions ; Smooth muscle ; Echinodermata ; Holothuria, Aspidochirotida
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy reveals that sarcolemmata of adjacent muscle cells form pentalaminar junctions by fusion of apposed trilaminar double leaflet membranes. These junctions appear to be candidates for low resistance pathways between muscle fibers. The muscles depolarize slowly when bathed in solutions containing elevated concentrations of KCl, and the sucrose gap method can then be used to measure the potential difference between polarized and depolarized regions. Thus the junctions which we have observed may provide the structural basis for electrical transmission through the sucrose gap.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00204778
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  • 46
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    Electronic Resource
    Penetration of the peritrophic membrane of the tick by Babesia microti (1982)
    Springer
    Cell & tissue research 221 (1982), S. 471-481 
    Details
    ISSN: 1432-0878
    Keywords: Peritrophic membrane ; Tick ; Babesia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A peritrophic membrane (PM) has been demonstrated in the gut of feeding larvae, nymphs, and adults of the tick Ixodes dammini. This is the first report of a PM in ticks. This temporary structure divides the lumen of the gut into two compartments, an endoperitrophic space, the lumen proper, and an ectoperitrophic space located between the PM and the epithelial cells of the gut wall. The PM is a mechanical barrier and even such small particles as ribosomes derived from ingested reticulocytes are retained in the lumen proper; they are never found in the ectoperitrophic compartment. In Ixodes dammini fed on hamsters infected with Babesia microti some of the parasites are found in the ectoperitrophic space. This passage is accomplished by a highly specialized organelle, the arrowhead, which develops in some Babesia during their metamorphosis in the gut of the vector. The arrowhead, while passing through the PM, changes its fine structure and loses its internal organization as if releasing some of its contents. Its disintegration continues and it disappears shortly after the Babesia have entered the epithelial cells. Only Babesia equipped with the arrowhead structure are able to cross the PM. This is the first documented case of a parasite traversing a solidified PM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215696
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  • 47
    Electronic Resource
    Electronic Resource
    Paddle cilia (discocilia) in chemosensitive structures of the gastropod mollusk Pleurobranchaea californica (1982)
    Springer
    Cell & tissue research 222 (1982), S. 25-40 
    Details
    ISSN: 1432-0878
    Keywords: Paddle cilia ; Discocilia ; Pleurobranchaea ; Chemoreceptors ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Scanning electron microscopy of various regions of the body of the marine gastropod Pleurobranchaea californica (McFarland) has revealed a characteristic cell type that bears cilia with dilated discoid-shaped tips. The tips of the cilia consist of an expansion of the ciliary membrane around a looped distal extension of the axoneme. These kinocilia have been observed in numerous other marine invertebrates and are generally referred to as paddle cilia (Tamarin et al. 1974) or discocilia (Heimler 1978). Although many functions have been proposed for paddle cilia, little empirical evidence supports any of the proposals. In Pleurobranchaea we have found that the distribution of this ciliated cell type corresponds exactly to areas of the body known from behavioral studies (Lee et al. 1974; Davis and Matera 1981) to mediate chemoreception. Transmission electron microscopy of the epithelium lining the rhinophores and tentacles of Pleurobranchaea revealed details of the ultrastructure of these ciliated cells and showed that they are primary receptors. These ciliated receptors lie in a yellow-brown pseudostratified columnar epithelium that superficially resembles the olfactory mucosa of vertebrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218286
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  • 48
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    Electronic Resource
    Pigment biogenesis in freshwater shrimp ventral nerve chord chromatophores (1982)
    Springer
    Cell & tissue research 222 (1982), S. 167-175 
    Details
    ISSN: 1432-0878
    Keywords: Pigment granules ; Chromatophores ; Granulogenesis ; Palaemonid shrimp ; Macrobrachium ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The possible biogenesis of two pigment granule types present in the monochromatic, brown chromatosomes enveloping the ventral nerve chord of the freshwater palaemonid shrimps Macrobrachium acanthurus, M. heterochirus and M. olfersii is examined by transmission electron microscopy in thin section and freeze fracture replicas. Prominent, membrane limited granules are suggested to have their origin in a complex, juxtanuclear, smooth endoplasmic reticulum labyrinth, continuous with the nuclear envelope. Amembranous, lipocarotenoid granules possibly derive from the external surface of the smooth endoplasmic reticulum. Nuclear envelope and SER membranes contain numerous 11 nm diameter intramembranous particles while pigment granule membranes exhibit fewer particles. A dictyosomal origin for the lipocarotenoid granules is discounted. Granulogenesis is suggested to be a continuous process in crustacean chromatophores.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218297
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  • 49
    Electronic Resource
    Electronic Resource
    Ultrastructural duality of extrafusal fibers in a slow (tonic) skeletal muscle (1982)
    Springer
    Cell & tissue research 222 (1982), S. 261-267 
    Details
    ISSN: 1432-0878
    Keywords: Skeletal muscle ; Fiber types ; Electron microscopy ; Stereology ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural and stereological assessment of the mature avian anterior latissimus dorsi (ALD) muscle showed that it contains two kinds of extrafusal fibers. This fine structural dichotomy of fiber types in the ALD correlated well with their previously reported histochemical duality. Distinct differences occur in sarcomere banding, myofibrillar area, sarcotubular and mitochondrial density, and in morphology of motor-nerve terminals. Both myofiber types in this muscle were interpreted as representing varieties of “slow” or tonic muscle fibers. Both fibers contain myofibrils that, despite differences in cross-sectional area, were large, irregular, and ribbon-shaped, typical of the “Felderstruktur” appearance of true “slow” fibers. Whereas the majority of fibers (type-1) are devoid of well-defined M-bands, the minor fiber population (type-2) exhibit prominent M-bands in the center of each sarcomere. In addition, type-1 tonic fibers contain a significantly lower mitochondrial and sarcotubular volume than the tonic fibers of type-2. While both fiber types exhibit motor-nerve terminals that are small, smooth and punctate in appearance, those on the type2 fibers often had a number of shallow postjunctional folds. Whether or not these two classes of extrafusal fiber in this muscle represent two separate and distinct types of motor units remains to be determined functionally.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213211
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  • 50
    Electronic Resource
    Electronic Resource
    Fine structure of arterial smooth muscle cells cultured in the presence of whole blood serum or plasma-derived serum (1982)
    Springer
    Cell & tissue research 223 (1982), S. 87-99 
    Details
    ISSN: 1432-0878
    Keywords: Smooth muscle cells ; In vitro-growth ; Whole blood serum ; Plasma-derived serum ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Normal diploid cells require serum to proliferate in culture. Platelet-derived growth factor has been identified as the main serum component responsible for this effect. Here, smooth muscle cells were isolated enzymatically from the aorta of 5-day-old rats and cultured in the presence of 10% whole blood serum (WBS) or plasma-derived serum (PDS), i.e. with or without platelet factor, and studied by transmission electron microscopy. The cells proliferated actively in WBS-medium but remained quiescent in PDS-medium. Fine structurally, cells from WBS-cultures demonstrated numerous mitochondria, an extensive rough endoplasmic reticulum (RER), a large Golgi complex, a few lysosomes, and microfilaments arranged in parallel bundles. After transfer to PDS-medium, the RER- and Golgi cisternae were markedly dilated and the number of membrane-associated ribosomes decreased. Segregation of fragments of cytoplasm within autophagosomes was frequently observed and the number of lysosomes increased. Lipid droplets were more abundant and often gathered in the Golgi area. Moreover, the cells had become more irregular in shape and showed many bleb-like processes at their surface. Microfilament bundles had also become more prominent and crossed each other in different directions. These observations show that the removal of platelet factor from the medium clearly modifies the fine structure of cultured smooth muscle cells. The findings are in good agreement with the concept that platelet factor not only supports the proliferation of cultured cells but also stimulates their secretory activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221501
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  • 51
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    Electronic Resource
    Effect of hyper- and hypoosmotic solutions on the structure of theAstacus retina (1982)
    Springer
    Cell & tissue research 223 (1982), S. 267-280 
    Details
    ISSN: 1432-0878
    Keywords: Retina (Astacus) ; Rhabdom ; Osmolarity ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Alterations of the retinula cells in the retina of the light-adapted crayfish in response to hyper- and hypoosmotic van Harreveld solutions was examined by transmission electron microscopy. Increased osmolarity of the bathing medium to twice that of the physiological value leads to shrinkage of the retinula-cell somata. Microvilli, on the other hand, do not undergo shrinkage. Some other characteristic irreversible changes do, however, take place, including detachment of microvilli from the soma, showing a two- or threefold increase in diameter, and a concomitant decrease in number, probably due to fusion of microvilli. Prolonged incubation or higher osmolarities (5 isosmol) cause alteration of the microvillar membranes to whorls. Structural changes are often restricted to microvillar stacks evaginating from certain individual retinular cells. The number of affected stacks increases depending on the duration of incubation or the osmotic pressure. Hypoosmotic solution (0.5 isosmol) also induces an increase of microvillar diameters and a concomitant reduction in number of microvilli per stack. Exposure to a 20% solution of glycerol causes destruction of the rhabdom structure and the formation of whorls from microvillar membranes. The present findings suggest that the structure of the microvilli is stabilized by an axial cytoskeleton.
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    URL: http://dx.doi.org/10.1007/BF01258488
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    Electronic Resource
    Interdigitating cells and macrophages in the acute involuting rat thymus (1982)
    Springer
    Cell & tissue research 224 (1982), S. 291-301 
    Details
    ISSN: 1432-0878
    Keywords: Thymus (rat) irradiation ; Electron microscopy ; Interdigitating cells ; Macrophages ; Phagocytosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Phagocytic activity and population development of medullary interdigitating cells (IDC) and cortical macrophages have been studied in the rat thymus after irradiation-induced thymocyte necrosis. IDC clearly demonstrate phagocytic activity, particularly in the 16h stage after irradiation. At this stage the number of necrotic thymocytes is maximal and the total number of phagocytic cells is insufficient to phagocytize all necrotic material. IDC increase in number slightly and are predominantly phagocytizing in the corticomedullary region (CMR), where they appear to develop from macrophage-like cells. The results indicate that medullary IDC can be phagocytic but have a different developmental pathway than cortical macrophages. Cortical macrophages greatly increase in number and acquire the appearance of tingible body macrophages by phagocytizing many necrotic thymocytes. They seem to develop from monocytes that normally enter the thymus at the CMR. During the acute involution macrophages probably also enter the cortex via the connective tissue capsule. It is suggested that thymus medullary IDC probably belong to the mononuclear phagocytes, as do the cortical macrophages. In the specific medullary environment IDC gradually develop their characteristic ultrastructure for an apparently other than phagocytic function. The similarities between IDC and epidermal Langerhans cells are discussed.
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    URL: http://dx.doi.org/10.1007/BF00216874
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  • 53
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    Electronic Resource
    Ultrastructural changes of the stigma of the follicle during the process of ovulation in the hen (1982)
    Springer
    Cell & tissue research 224 (1982), S. 349-359 
    Details
    ISSN: 1432-0878
    Keywords: Ovarian follicle ; Ovulation ; Ultrastructural change ; Fowl ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary No structural changes could be observed in the stigma until 2 h before ovulation. Within a few minutes of ovulation, the stratum granulosum and theca interna disappear completely in the middle part of the stigma. By 30 min before ovulation, the rough endoplasmic reticulum in the fibroblasts of the theca externa develops conspicuously. Then a few minutes before ovulation, the theca externa becomes much thinner with a conspicuous disintegration of the collagenous fibers into individual fibrils. These structural changes may contribute to the fragility of the stigma tissue and induce rupture of the follicle.
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    URL: http://dx.doi.org/10.1007/BF00216878
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  • 54
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    Electronic Resource
    Cellular interconnections in the young mouse ovary (1982)
    Springer
    Cell & tissue research 224 (1982), S. 383-395 
    Details
    ISSN: 1432-0878
    Keywords: Mouse ovary ; Junctions ; Freeze-fracture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Intercellular junctions in the young mouse ovary were examined by electron microscopy utilizing freeze-fracture and thin-sectioning techniques. Projections from the granulosa cells adjacent to the oocyte (GI) traverse the zona pellucida and form small gap junctions on the oocyte surface. On the P-face of these cells, the junctional aggregations are occasionally associated with linear strands of particles. In contrast, large gap junctional areas are frequently observed between the more peripherally located granulosa cells (GE) and are also present in the theca interna (TI) cell layer surrounding the follicles. Three types of tight junctional strands are discernible on the P-face of theca externa cells (TE): angularly zigzag strands consisting of intermittently distributed intramembranous particles on wide ridges, intermediate zigzag strands consisting of more continuously distributed particles, and wavy strands consisting of rather fused particles. Tight junctional strands are also present in the middle of grooves on the E-face of endothelial cells of blood vessels. In the germinal epithelial cell layer, tight junctional strands appear to be discrete and form a less anastomosing network.
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    URL: http://dx.doi.org/10.1007/BF00216881
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  • 55
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    Ultrastructure of the pars intermedia of the developing sheep hypophysis (1982)
    Springer
    Cell & tissue research 224 (1982), S. 369-381 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Pars intermedia ; Electron microscopy ; Fetal sheep ; Lamb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using light and electron microscopy, the morphogenesis of the pars intermedia of the sheep pituitary gland was examined in developing lambs between 26 days of gestation and the newborn stage. Following the establishment of contact between the anterior and posterior lobe primordia seen at 26 days, the connection with the pharyngeal roof disappeared by 31 days. The lumen of Rathke's pouch, which was a prominent cavity at the earlier stages, became inconspicuous by 40 days but progressively increased in size during gestation and, in some newborn animals, contained colloid material. At 40 days, the pars intermedia consisted of a uniform population of undifferentiated cells. Cells with cytoplasmic granules were first identified at 50 days. The cytological appearance of granular cells at 70 days indicated increased synthetic activity and by 80 days they closely resembled adult glandular cells. At 100 days, membrane activity suggestive of exocytosis was first observed in granular cells; fenestrated capillaries were present, and early follicle formation between adjacent non-granular cells was seen. This apparent exocytotic release of granules was observed much more frequently between 100 days of gestation and the newborn stage than in adult pars intermedia cells. These findings indicate that glandular cells of the developing pars intermedia are actively engaged in synthesis, storage and secretion from an early stage.
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    URL: http://dx.doi.org/10.1007/BF00216880
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  • 56
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    Electronic Resource
    Endometrial ultrastructure in the early uterine response to blastocysts and artificial deciduogenic stimuli in rats (1982)
    Springer
    Cell & tissue research 225 (1982), S. 355-364 
    Details
    ISSN: 1432-0878
    Keywords: Implantation ; Blastocyst ; Pontamine ; blue reaction ; Decidualization ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The early uterine response to transplanted, delayed and estrogenactivated blastocysts was studied ultrastructurally and compared with that induced by intrauterine instillations of deciduogenic agents (arachis oil, air). The uterine responses to delayed and activated blastocysts showed no ultrastructural or temporal differences. Already within 4 h after transfer to a sensitized uterus, the delayed blastocysts exhibited signs of activation, and both types of blastocysts had started to attach onto an undamaged epithelial lining. Signs of stromal cell differentiation into decidual cells were also seen as early as 4 h after transfer, while the Pontamine-blue reaction did not appear until after 8 h. The results therefore indicate that the transplanted blastocysts induced decidualization atraumatically and that the delayed blastocysts were either deciduogenic already before transfer or rapidly acquired deciduogenic properties after transfer. Artificial decidual induction with oil and air led to damage or death of a large number of cells in the uterine luminal epithelium. Within only 15 min after instillation pronounced signs of cell damage were seen, and later numerous cells were extruded from the epithelial lining. In the stroma ultrastructural signs of decidual cell differentiation and a Pontamine-blue reaction were observed as early as 4 h after induction. It is therefore suggested that oil and air induce decidualization via the epithelium by means of trauma.
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    URL: http://dx.doi.org/10.1007/BF00214688
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  • 57
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    Electronic Resource
    Ultrastructural studies on the ventricular surface of the frog cerebellum (1982)
    Springer
    Cell & tissue research 225 (1982), S. 443-448 
    Details
    ISSN: 1432-0878
    Keywords: Frog cerebellum ; Ependymal surface ; Cilia ; Supraependymal cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural studies of the ventricular surface of the frog cerebellum showed regional differences. In the midline region of the adult cerebellum was found a band of profusely ciliated squamous ependymal cells. In the rest of the cerebellum the ependymal cells were columnar and each had a single cilium. In the cerebellum of the premetamorphic tadpole, the squamous ependymal cells of the midline region also were monociliated. During metamorphosis they gradually became multiciliated. Additionally, supraependymal cells and synaptic elements were present on the ventricular surface of the cerebellum of adult frogs as well as in late metamorphic tadpoles. In contrast, supraependymal cells were rarely observed in premetamorphic tadpoles, and it was concluded that the supraependymal system develops during metamorphosis. It is postulated that the band of cilia may be associated with the circulation of cerebrospinal fluid, and supraependymal synaptic elements function in neuroendocrine regulation.
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    URL: http://dx.doi.org/10.1007/BF00214695
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  • 58
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    Further studies on the junctional complex in the intestine of Sagitta setosa (1982)
    Springer
    Cell & tissue research 225 (1982), S. 663-671 
    Details
    ISSN: 1432-0878
    Keywords: Chaetognatha ; Intestine ; Pleated septate junction ; Electron microscopy ; Freeze-fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The intramembrane structures of the pleated septate junction which occur in the junctional complex of the intestine of the chaetognath Sagitta setosa have been investigated. The pleated septate junction is made up of linear rows of irregularly shaped and sized particles, often fused into short rods, and pits which can be fused into furrows. The distribution of these structures on E and P faces depends upon the preparative methods used. Many of the morphological characteristics are the same as those of the “lower invertebrate pleated septate junction type” defined by Green (1981a). The physiological significance of this junction is obscure. On the basis of the presence of septate junctions (both of the paired septate junction and pleated septate junction types) which have mainly morphological characteristics of the “lower invertebrate pleated septate junction” we can add to the hypothesis that chaetognaths are not related to the molluscs and arthropods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214811
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    An immunocytochemical and electron-microscopical study of endocrine cells in the gut and pancreas of a stomachless teleost fish, Barbus conchonius (Cyprinidae) (1982)
    Springer
    Cell & tissue research 227 (1982), S. 577-593 
    Details
    ISSN: 1432-0878
    Keywords: Enteroendocrine cells ; Pancreatic endocrine cells ; Gastroenteropancreatic hormones ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Four immunoreactive endocrine cell types can be distinguished in the pancreatic islets of B. conchonius: insulin-producing B cells, somatostatin-producing A1 (= D) cells, glucagon-producing A2 cells and pancreatic poly-peptide-producing PP cells. The principal islet of this species contains only a few PP cells, while many PP cells are present in the smaller islets. Except for the B cell all pancreatic endocrine cell types are also present in the pancreatic duct. At least six enteroendocrine cell types are present in the gut of B. conchonius: 1. a cell type (I) with small secretory granules, present throughout the intestine, and possibly involved in the regulation of gut motility; 2. a C-terminal gastrin immunoreactive cell, probably producing a caerulein-like peptide; these cells are located at the upper parts of the folds, especially in the proximal part of the intestinal bulb; 3. a met-enkephalin-immunoreactive cell, present throughout the first segment; 4. a glucagon-immunoreactive cell, which is rare in the first segment; 5. a PP-immunoreactive cell, mainly present in the first half of the first segment; 6. an immunoreactive cell, which cannot at present be specified, located in the intestinal bulb. The latter four cell types are mostly located in the basal parts of the folds, although some PP-immunoreactive cells can also be found in the upper parts. Most if not all enteroendocrine cells are of the open type. The possible functions of all enteroendocrine cell types are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00204788
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  • 60
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    Electronic Resource
    Splenic white pulp as a thymus-independent area in the African clawed toad, Xenopus laevis (1982)
    Springer
    Cell & tissue research 226 (1982), S. 327-335 
    Details
    ISSN: 1432-0878
    Keywords: Xenopus ; Spleen ; B-lymphocyte ; Immunofluorescence ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An indirect immunofluorescence study of the frozen sections of the spleen of an anuran amphibian, Xenopus laevis, showed that lymphocytes bearing a small amount of immunoglobulin (Ig) were localized mostly in the white pulp of non-immunized toads. There were fewer fluorescent cells in the red pulp. In the toads hyperimmunized with human gamma globulin (HGG), cells with strong cytoplasmic fluorescence increased significantly in the outer part of the white pulp. Electron microscopy of spleens from these toads showed that plasma cells at different stages of maturation were abundant in the white pulp, whereas in the red pulp, a smaller number of maturer plasma cells were observed. These results indicate that, in contrast with its mammalian counterpart, the splenic white pulp of this anuran is the site where thymusin-dependent lymphocytes commence blast formation and transformation into plasma cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218363
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    Effects of buffer gases on the infrared multiphoton dissociation of C2H4DCl: A chemical clock to explore highly excited molecules (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 327-349 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Observations are reported of the effect of the buffer gases He, Ne, and CF4, in the pressure range of 0-30 torr, on the branching ratio [HCl]/[DCl] of the unimolecular decomposition The ratio R = kH/kD has been measured in high-pressure thermal decomposition (670-1100 K) and was shown to give a unique measure of the internal energy of the decomposing molecules and hence, with RRKM theory and pressure fall-off data, a time scale for their decomposition.Applying the thermal data to the photolysis leads to the conclusion that excitation and decomposition are produced by the laser spike (high intensity, 70 ns FWHM) and also at a slower rate by the larger, less intense tail (1.6 μs). Added buffer gases quench the latter, leaving the former which, from measurements of R, is shown to correspond to excitations of 115 ± 15 kcal/mol and lifetimes of ∼30 ps. No bond breaking is seen despite the high energies, in accord with theoretical expectations. The results require an enhanced rate of photon absorption by the highly excited molecules, which are about hundredfold greater than that observed for 300 K molecules. Data are also reported for C2H2F2 and the secondary multiphoton photolysis of the ethylenes produced. Effects of beam geometry and wavelength are explored.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140402
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  • 62
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    Electronic Resource
    Rate constants for the reaction of ground-state oxygen atoms with methanol from 297 to 544 KN.R.C.C. No. 19814. (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 371-379 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rate constant for the reaction of ground-state oxygen atoms with methanol has been determined between 297 and 544 K by a phase-shift technique using mercury photosensitized decomposition of N2O to generate oxygen atoms. The relative oxygen atom concentration was monitored by the chemiluminescence from the reaction of oxygen atoms with nitric oxide. The results are accommodated by the Arrhenius expression k1 = (9.79 ± 2.71) × 1012 exp[(-2267 ± 111)/T]cm3/mol·s, where the indicated uncertainties are 95% confidence limits for 10 degrees of freedom. As an incidental part of this work, the third-body efficiency of CH3OH relative to N2O for the reaction O + NO + M → NO2 + M (M = CH3OH) was determined to be 3.1 at 298 K.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140405
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  • 63
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    Surface oxygen bond energy, and kinetics and catalysis on perovskite oxide catalysts (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 435-438 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    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/kin.550140409
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  • 64
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    Electronic Resource
    Temperature and third-body dependence of the rate constant for the reaction O + O2 + M → O3 + M (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 417-434 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The flash photolysis resonance fluorescence technique was used to measure the rate constants of the reaction O + O2 + M → O3 + M (M = N2, O2, Ar, and He) as a function of temperature. The results for the rate constants are given by The activation energies with N2, O2, and Ar as third bodies are equal within the experimental error, (-1370 → 340 cal/mol), and the relative third-body efficiencies at 298 K for N2, O2, Ar, and He are 1.00, 0.99, 0.69, and 0.60, respectively.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140408
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  • 65
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    Cyclobutane production via the O3--thiolane reaction (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 439-445 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    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/kin.550140410
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  • 66
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    Electronic Resource
    An empirical formula for gas-wall collision efficiencies in VLPP experiments (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 447-450 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550140411
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  • 67
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    Kinetics and mechanism of the gas-phase thermal reaction between bis(fluoroxy) difluoromethane CF2(OF)2 and carbon monoxide (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 647-657 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of the gas-phase thermal reaction between CF2(OF)2 and CO has been studied in a static system at temperatures ranging between 110 and 140°C. The only reaction products were CF2O and CO2, giving the following stoichiometry: \documentclass{article}\pagestyle{empty}\begin{document}$${\rm CF}_{\rm 2} {\rm (OF)}_{\rm 2} {\rm + 2CO = 2CF}_{\rm 2} {\rm O + CO}_{\rm 2} {\rm}\Delta n{\rm = 0}$$\end{document} The reaction is homogeneous. The rate is strictly second order in CF2(OF)2 and CO, and is not affected by the total pressure or by the presence of reaction products. Oxygen promotes a sensitized oxidation of CO and inhibits the formation of CF2O.The experimental results in the absence of oxygen can be explained by a chain mechanism similar to that proposed for the reaction between F2O and CO with an overall rate constant of \documentclass{article}\pagestyle{empty}\begin{document}$$k_1 = 1.45 \times 10^9 {\rm exp}(- 20,900/RT)L/mol \cdot s$$\end{document} From the experimental data obtained on the oxygen-inhibited reaction, the rate constant for the primary process can be calculated: \documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{*{20}c} {({\rm I})} \quad {{\rm CF}_{\rm 2} ({\rm OF)}_{\rm 2} + {\rm CO} \to {\rm CF}_{\rm 2} (\mathop {\rm O}\limits^{\rm .}){\rm OF} + {\rm F}\mathop {\rm C}\limits^{\rm .} {\rm O}} \quad\quad {k_1 = 1.45 \times 10^9 {\rm exp}(- 20,900/RT)L/mol \cdot s} \\\end{array}$$\end{document} The chain length v = 2.5 is independent of the temperature. Taking for collision diameters σCF2(OF)2 = 6 Å and σCO = 3.74 Å, a value α = 5.3 × 10-3 for the steric factor is obtained.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140607
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  • 68
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    The kinetics of the gas-phase reaction between iodine and phenylsilane and the bond dissociation energy D(C6H5SiH2—H) (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 669-677 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The title reaction has been investigated in the temperature range of 490-573 K. Initial reactant pressures were varied in the range of 0.2-5.2 torr (I2) and 2-20 torr (C6H5SiH3). The rate of iodine consumption, monitored spectrophotometrically, was found to obey \documentclass{article}\pagestyle{empty}\begin{document}$$ - \frac{{d[{\rm I}_{\rm 2}]}}{{dt}} = \frac{{k_{3/2} [{\rm I}_{\rm 2}]^{{\raise0.7ex\hbox{$1$} \!\mathord{\left/ {\vphantom {1 2}}\right.\kern-\nulldelimiterspace} \!\lower0.7ex\hbox{$2$}}} [{\rm C}_{\rm 6} {\rm H}_{\rm 5} {\rm SiH}_{\rm 3}]}}{{1 + k'[HI]/[I_2]}}$$\end{document} both by initial rate and integrated equation fitting procedures. The effect of added initial HI conformed to this expression. The data are consistent with a conventional I-atom propagated chain reaction, and for the step \documentclass{article}\pagestyle{empty}\begin{document}$${\rm I}^{\rm .} + {\rm C}_{\rm 6} {\rm H}_{\rm 5} {\rm SiH}_{\rm 3} \to {\rm C}_{\rm 6} {\rm H}_{\rm 5} \mathop {\rm S}\limits^{\rm .} {\rm iH}_{\rm 2} + {\rm HI}$$\end{document} the rate constant is given by \documentclass{article}\pagestyle{empty}\begin{document}$${\rm log}k_1 (dm^3 /mol \cdot s) = (11.52 \pm 0.08) - (76.8 \pm 0.8{\rm kJ/mol})/RT{\rm ln}10$$\end{document} From this is derived the bond dissociation energy value C6H5SiH2—H = 374 kJ/mol(88 kcal/mol). A comparison with other Si—H dissociation energy values indicates that the “silabenzyl” stabilization energy is small, ≈7 kJ/mol.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140609
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  • 69
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    The oxidation of diethylhydroxylamine by nitrogen dioxide (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 699-710 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Diethylhydroxylamine, (C2H5)2NOH, was oxidized by NO2 at 25°C in a long-path-length infrared gas cell. The measured products of the reaction were HONO and CH3CHO. The reaction scheme which explains the reaction is was oxidized by NO2, and the reaction was found to be very rapid with k1 〉 10-16 cm3/s. The products of the reaction were verified by both infrared absorption (CH3CHO, C2H5NO) and gas chromatography (CH3CHO, NO).
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140611
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  • 70
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    Electronic Resource
    Mechanism of oxidation of phenylthioacetic acids by potassium peroxodiphosphate (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 789-799 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rates of oxidation of phenylthioacetic acid (PTAA) and several substituted phenylthioacetic acids by potassium peroxodiphosphate (PP) in 50% (v/v) aqueous acetic acid have been studied in detail. The rate of oxidation is expressed as \documentclass{article}\pagestyle{empty}\begin{document}$$\frac{{- d[{\rm PP]}}}{{{\rm dt}}} = k[{\rm PP][PTAA][H}^{\rm +}]$$\end{document}An analysis of the dependence of the rate on [H+] reveals that H3P2O8- is the active oxidizing species in the oxidation. The effect of ring substituents on the rate gives a ρ+ value of -0.45 ± 0.03 (r = 0.998, s = 0.02 at 40°C), pointing to the development of an electron-deficient center in the transition state. The results are discussed in terms of a mechanism involving the rate-determining formation of an intermediate between PP and phenylthioacetic acids, followed by the decomposition of the intermediate. These kinetic results are compared with those obtained in the oxidation of phenylthioacetic acids by peroxodisulfate.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550140707
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  • 71
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    Electron transfer reactions of V(IV) with Cl(I), Br(I) and I(I). A kinetic study (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 801-811 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A kinetic study on the oxidation of V(IV) by chloramine-T (CAT) at pH 6.85 by N-bromo succinimide (NBS) in aqueous acetic acid-perchloric acid media and by N-iodo succinimide (NIS) in aqueous perchloric acid medium has been carried out. In all the systems studied the order with respect to the oxidant is unity. NBS and CAT oxidation reactions exhibited Michaelis-Menten type kinetics, and the NIS study indicated unit dependence on [substrate]. Independence on acidity has been observed in the case of CAT and NBS reactions, but NIS reactions exhibited inverse unit dependence on [acid]. Novel solvent influences have been noticed in the case of CAT reactions, but with NIS and NBS reactions retardation in the rate has been observed with an increase in the percentage of acetic acid. Plausible mechanisms consistent with the results have been postulated, and suitable rate laws in consonance with the postulated mechanisms have been derived.
    Additional Material: 7 Tab.
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    URL: http://dx.doi.org/10.1002/kin.550140708
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  • 72
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    Reply to “comments on ‘a smog chamber and modeling study of the gas phase NOx-air photooxidation of toluene and the cresols’” (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 813-814 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550140709
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    Masthead (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982) 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550140801
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  • 74
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    A dual-frequency Belousov Zhabotinskii oscillating reaction with ethyl acetoacetate as organic substrate (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 815-821 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The experimental behavior of the cerium- and manganese-catalyzed Belousov Zhabotinskii oscillating reaction with ethyl acetoacetate as organic substrate has been investigated. Under certain conditions the system displays two types of temporal oscillations. Damped highfrequency oscillations appear immediately after the addition of potassium bromate solution to complete the reaction mixture. These high-frequency oscillations may be regarded as being superimposed on an induction period of the type found in the reaction using malonic acid. After the induction period, low-frequency oscillations of the normal type are obtained. Both the high-frequency and the low-frequency oscillations can be monitored with a platinum redox or with a bromide specific ion electrode.
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    URL: http://dx.doi.org/10.1002/kin.550140802
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  • 75
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    Rate constants for the gas-phase reaction of OH radicals with a series of ketones at 299 ± 2 K (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 839-847 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Relative rate constants for the reaction of OH radicals with a series of ketones have been determined at 299 ± 2 K, using methyl nitrite photolysis in air as a source of hydroxyl radicals. Using a rate constant for the reaction of OH radicals with cyclohexane of 7.57 × 10-12 cm3 molecule-1 s-1, the rate constants obtained are (× 1012 cm3 molecule-1 s-1): 2-pentanone, 4.74 ± 0.14; 3-pentanone, 1.85 ± 0.34; 2-hexanone, 9.16 ± 0.61; 3-hexanone, 6.96 ± 0.29; 2,4-dimethyl-3-pentanone, 5.43 ± 0.41; 4-methyl-2-pentanone, 14.5 ± 0.7; and 2,6-dimethyl-4-heptanone, 27.7 ± 1.5. These rate constants indicate that while the carbonyl group decreases the reactivity of C—H bonds in the α position toward reaction with the OH radical, it enhances the reactivity in the β position.
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  • 76
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    The reaction of methyl p-nitrophenyl sulfate with hydrogen peroxide anion determination of pKa of hydrogen peroxide in methanol by a kinetic spectrophotometric procedure (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 823-837 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A kinetic spectrophotometric investigation of the reaction of the hydrogen peroxide anion with methyl p-nitrophenyl sulfate in methanol solvent resulted in the evaluation of the pKa of HOOH in methanol at 25°C as 15.8 ± 0.2. Since normal kinetic procedures for the determination of the equilibrium constant K for the process CH3O- + H2O2 ⇄ CH3OH + HO2- were found to be associated with high uncertainty, another procedure was devised to establish the magnitude of K. This method is based on an analysis of the changing slopes of plots of pseudo-first-order rate constants against the total base concentration as the stoichiometric amount of hydrogen peroxide is varied. The method is applicable to any system in which anionic nucleophiles generated in situ compete with solvent anions. Such a corroboration of kinetically determined equilibrium constants is believed essential. The kinetic data allow the specific rate constant kHOO-for the reaction of methyl p-nitrophenyl sulfate with hydrogen peroxide anions to be evaluated and yield the rate constant ratio kHOO-/kMeO- = 8.8 ± 2.2. This confirms the existence of an α effect at saturated carbon in this system.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140803
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  • 77
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    Thiocyanate-assisted demetallation of α,β,γ,δ-tetra(p-sulfophenyl)porphinatoindium(III) in aqueous media (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 849-859 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rate law for the demetallation of the title indium(III)-porphin complex in aqueous acidic thiocyanate media at 3.00M ionic strength was found to be of the form \documentclass{article}\pagestyle{empty}\begin{document}$$+ \frac{{d{\rm [H}_{\rm 4} {\rm P}^{{\rm 2} - } {\rm]}}}{{dt}} = \frac{{ab[{\rm H}^{\rm + }]^2 [{\rm NCS}^ -]^2 }}{{1 + b[{\rm H}^{\rm + }]^2 }}[{\rm InP]}_{\rm t}$$\end{document} where [H4P2-] is the concentration of the diacid product formed, [InP]t is the total concentration of all forms of indium(III)-porphin complex present, and a and b are constants. The constant a is a pseudo-third-order rate constant with the value (0.057 ± 0.005)M-2 s-1 and b has the value 0.704M-2 at 50.5°C. If the mechanism for demetallation involves ringpuckering with the attachment of two H+ ions, then 1/b can be identified with the product K1K2 for the stepwise dissociation of two protons from two ring pyrrolic nitrogen atoms of H2InP-. In the sulfonated tetraphenylporphin used for these studies the ring pyrrolic nitrogen atoms seem to be the most probable sites for protonation. If this identification is correct, the value of 1.42 ± 0.13 found for the product K1K2 shows the enormous effect that the presence of the In3+ center has on the ionization constants of these two protons. That the kinetic studies show saturation effects with respect to proton addition to InP3- may result from the fact that In3+ sits about 0.6 Å above the porphin ring.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140805
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  • 78
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    Kinetics and mechanism of base-catalyzed cleavage of some bicyclo[4.2.0.]octa-1,3,5-trien-7-one (benzocyclobuten-1(2H)-one) derivatives (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 893-902 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of cleavage of 3-hydroxybicyclo[4.2.0]octa-1,3,5-trien-7-ones in aqueous sodium hydroxide, and of the alkoxy and acetoxy analogues in methanolic sodium methoxide solution, were examined under pseudo-first-order reaction conditions. The dependence of the rate upon the basicity of the solvent, whether measured by H- or by [OR-], reflects the possible structure of the transition state. The deduced mechanism is also supported by the effects of substituents upon the reaction rate. The relative amounts of the volatile reaction products derived from o-toluic acid and from phenylacetic acid are understood in terms of the substituent effect upon the relative stabilities of the carbanions.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140808
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    Kinetics of the isomerization reaction of cholest-5-en-3-one catalyzed by trichloroacetic acid in aprotic solvents of low dielectric constant (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 875-891 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The isomerization reaction of cholest-5-en-3-one has been studied in a solution of cyclohexane using trichloroacetic acid as catalyst. At the same time a general reaction scheme is proposed to be valid for all the cases assayed in which the monomer form of the acid is considered as the only effective catalyst. The experimental results agree with these hypotheses and with the calculation of the individual rate constant together with the reaction order with respect to the catalyst. Semiquantitative studies have been carried out with other catalysts and solvents, confirming the validity of the reaction scheme. The thermodynamic activation parameters have also been calculated, and a comparative study was made with the results of the evaluation of the reaction when it takes place in amphiprotic solvents. A reaction mechanism is proposed based on all the kinetic information obtained.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140807
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  • 80
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    Basic hydrolysis of glyceryl nitrate esters. I. 1-glyceryl and 2-glyceryl nitrate esters (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 903-917 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Kinetics of the basic hydrolysis of 1-glyceryl mononitrate (1-MNG) and 2-glyceryl mononitrate (2-MNG) were investigated in CO2-free aqueous calcium hydroxide solutions. The hydrolysis reactions were carried out in a temperature-controlled reactor vessel with provision for continuous N2 sparging of the reaction mixture. Both glyceryl nitrate esters hydrolyzed via second-order reaction at 25°C. 2-MNG in calcium hydroxide solution isomerized to 1-MNG, which subsequently hydrolyzed to form NO3-. In strongly basic aqueous solutions of NaOH (30%), 2-MNG is converted to glycidol and NO3-.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140809
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  • 81
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    Kinetics of the gas-phase reactions of OH radicals with alkyl nitrates at 299 ± 2 K (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 919-926 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Relative rate constants for the gas-phase reactions of OH radicals with a series of alkyl nitrates have been determined at 299 ± 2 K, using methyl nitrite photolysis in air as a source of OH radicals. Using a rate constant for the reaction of OH radicals with cyclohexane of 7.57 × 10-12 cm3/molec·s, the rate constants obtained are (× 1012 cm3/molec·s): 2-propyl nitrate, 0.18 ± 0.05; 1-butyl nitrate, 1.42 ± 0.11; 2-butyl nitrate, 0.69 ± 0.10; 2-pentyl nitrate, 1.87 ± 0.12; 3-pentyl nitrate, 1.13 ± 0.20; 2-hexyl nitrate, 3.19 ± 0.16; 3-hexyl nitrate, 2.72 ± 0.22; 3-heptyl nitrate, 3.72 ± 0.43; and 3-octyl nitrate, 3.91 ± 0.80. These rate constants, which are the first reported for the alkyl nitrates, are significantly lower than those for the parent alkanes, and a formula, based on the numbers of the various types of C—H bonds in the alkyl nitrates, is derived for rate constant estimation purposes.
    Additional Material: 3 Ill.
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  • 82
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    A reexamination of the pyrolysis of bis trifluoromethyl peroxide (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 933-944 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The literature results for the pyrolysis of bis trifluoromethyl peroxide are reexamined and compared with those for dimethyl peroxide. The thermochemistry yields the result that the π-bond energy in carbonyl fluoride is 96 ± 10 kcal/mol compared to 74 kcal/mol for that in formaldehyde. Thermodynamic additivity contributions are derived for the C—(F)3(O) and O—(C)(F) groups. Some conclusions are drawn in relation to the oxidation of halogeno methyl radicals and the chemistry of the atmosphere.
    Additional Material: 4 Tab.
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    URL: http://dx.doi.org/10.1002/kin.550140812
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  • 83
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    Mechanism of the hydroxyiodination of 2-butenoic acid (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 927-932 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aqueous iodination of trans-2-butenoic acid proceeds via hydrolysis of I2 to form HOI and I-, then rapid addition of HOI across the double bond to form the iodohydrin product. In the presence of iodate to keep iodide concentration low, the reaction proceeds at a conveniently measurable rate. The rate for the addition reaction \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm HOI + CH}_{\rm 3} {\rm CH=\!=CHCOOH} \to {\rm CH}_{\rm 3} {\rm CH(OH)CHICOOH}$$ \end{document} is -d[C4H6O2]/dt = 5900 [H+][C4H6O2][HOI]M/s at 25.0°C when [IO3-] = 0.025M and ionic strength = 0.3. The overall rate law in the presence of iodate is \documentclass{article}\pagestyle{empty}\begin{document}$$ -d[{\rm I}_{\rm 2}]/dt = 3.2 \times 10^{ - 3} \times 10^{ - 3} [{\rm H}^{\rm + }][{\rm IO}_{\rm 3}^ -]^{0.65} [{\rm C}_{\rm 4} {\rm H}_{\rm 6} {\rm O}_{\rm 2}]^{1/2} [{\rm I}_{\rm 2}]^{1/2} M/{\rm s}$$ \end{document} where [H+] and [IO3-] are total concentrations used to prepare the solution.
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  • 84
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    Kinetics and mechanism of the thermal decomposition of methyl isocyanate (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 945-952 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of gas-phase decomposition of methyl isocyanate have been investigated in the range of 427-548°C. Two decomposition routes are followed; the predominant one is a radical-chain process giving CO, H2, and HCN as major products, which has an order of 1.5 and an Arrhenius equation given by log k(L1/2/mol1/2·s) = (13.12 ± 0.06) - (56,450 ± 1670) cal/mol/2.303 RT. The minor route is the bimolecular formation of N,N′-dimethylcarbodiimide and CO2, which from the low activation parameters Ea = 31.6 kcal, A = 105.30 L1/2/mol1/2·s, and the reaction order of 1.57 appears to be heterogeneous.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140813
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    Masthead (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982) 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550140901
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  • 86
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    Pyridiniumchlorochromate oxidations: Studies on the kinetics and substituent effect in the oxidation of aniline in nonaqueous systems (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 977-984 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyridiniumchlorochromate (PCC) oxidizes aniline and substituted anilines except nitro anilines smoothly in chlorobenzene-nitrobenzene mixtures in the presence of dichloroacetic acid. The reaction has unit dependence on each of the aniline, PCC, and dichloroacetic acid concentrations. Electron-releasing substituents accelerate the reaction, whereas electronwithdrawing groups retard the reaction, and the rate data obey Hammett's relationship. The reaction constant ρ is -3.75. Azobenzene and p-benzoquinone have been obtained as products. The observed experimental data have been rationalized in terms of the formation of an intermediate complex involving PCC-amine undergoing a rapid decomposition to products.
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  • 87
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    Quantitative treatment of the effect of counterions on ctab-catalyzed reactions of stabilized carbonium ions with cyanide ion (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 1007-1015 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reactions of stabilized carbonium ions of setoglaucin, methyl violet, and ethyl violet with cyanide ions are largely catalyzed by the cationic micelles of cetyltrimethylammonium bromide (CTAB) in aqueous media. Added counterions (anions in this case) have strong inhibitory effects on the CTAB-catalyzed reactions in the following order: N3- 〉 NO3- 〉 Br- 〉 Cl- 〉 F- 〉 no salt. The inhibitory effects of the counterions have been attributed to the exchange between added anions and reagent (CN-) in the micellar media. The data have been analyzed by the model schemes, and mathematical formulations were developed. Various parameters associated with the exchange process, such as equilibrium exchange constant, number of surfactant molecules per substrate molecule, number of added anions, and a factor related to the binding of additives to the catalytic micellar aggregates, have been evaluated.
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  • 88
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    Kinetics and mechanisms of oxidation of organic compounds by silver(II) species. Part VI: Iminodiacetic acid and N-methyliminodiacetic acidFor Part V, see C. Baiocchi and E. Mentasti, Trans. Metal Chem., 5, 259 (1980). (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 1017-1032 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics and mechanism of oxidation of iminodiacetic acid and N-methyliminodiacetic acid by aquasilver(II) and Ag(II)-2,2′-bipyridine complexes has been investigated. The results are discussed with reference to the active reaction pathways, the equilibrium quotient of the title reactions, the protolytic equilibria which involve the oxidizing complex, and the intrinsic self-exchange rates of the oxidants.
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  • 89
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    Analysis of the unimolecular reaction N2O5 + M ⇌ NO2 + NO3 + M (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 399-416 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Recent experimental results on the thermal decomposition of N2O5 in N2 are evaluated in terms of unimolecular rate theory. A theoretically consistent set of fall-off curves is constructed which allows to identify experimental errors or misinterpretations. Limiting rate constants k0 = [N2] 2.2 × 10-3 (T/300)-4.4 exp(-11,080/T) cm3/molec·s over the range of 220-300 K, k∞ = 9.7 × 1014 (T/300)+0.1 exp(-11,080/T) s-1 over the range of 220-300 K, and broadening factors of the fall-off curve Fcent = exp(-T/250) + exp(-1050/T) over the range of 220-520 K have been derived. NO2 + NO3 recombination rate constants over the range of 200-300 K are krec,0 = [N2] 3.7 × 10-30 (T/300)-4.1 cm6/molec2·s and krec,∞ = 1.6 × 10-12 (T/300)+0.2 cm3/molec·s.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550140407
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  • 90
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    The kinetics and mechanisms of the gas-phase unimolecular eliminations of halogeno esters. Participation of the carbomethoxy group (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 381-397 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of the gas-phase elimination of several chloroesters were determined in a static system over the temperature range of 410-490°C and the pressure range of 47-236 torr. The reactions in seasoned vessels, and in the presence of a free-radical inhibitor, are homogeneous, unimolecular, and follow a first-order law. The temperature dependence of the rate coefficients is given by the following Arrhenius equations: for methyl 3-chloropropionate, log k1(s-1) = (13.22 ± 0.07) - (231.5 ± 1.0) kJ/mol/2.303RT; for methyl 4-chlorobutyrate, log k1(s-1) = (13.31 ± 0.25) - (221.5 ± 3.4) kJ/mol/2.303RT; and for methyl 5-chlorovalerate, log k1(s-1) = (13.12 ± 0.25) - (221.7 ± 3.2) kJ/mol/2.303RT. Rate enhancements and lactone formation reveal the participation of carbonyl oxygen of the carbomethoxy group. The order COOCH3-5 〉 COOCH3-6 〉 COOCH3-4 in assistance is similar to the sequence of group participation in solvolysis reactions. The partial rates for the parallel eliminations to normal dehydrohalogenation products and lactones have been estimated and reported. The present results lead us to consider that an intimate ion-pair mechanism through participation of the carbomethoxy group may well be operating in some of these reactions.
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  • 91
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    Estimation of rate constants from growth and decay data (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 517-534 
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    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Many experiments in chemical kinetics are initiated by a fast pulse, such as electric discharge, shock wave, flash lamp, or laser. After this pulse one observes the production and subsequent decay of a reactive intermediate. One then postulates a mechanism and adjusts the associated rate constants so as to minimize the difference between the results of the experiment and the prediction of the mechanism. The parameters to be estimated are usually strongly correlated, so that it is not possible to determine them separately. These estimated parameters are of little value unless we can also estimate statistically valid confidence limits for them. The difficulties are discussed which frequently arise in estimating parameters and confidence limits for a kinetic mechanism which is widely used in interpreting laser excitation and fluorescence measurements, that is, first-order production and decay. These difficulties, and methods for dealing with them, are illustrated with realistic data. The estimation problem is particularly ill conditioned when the production and loss rates are nearly equal. In some experimental systems this can be avoided, but in others it is inevitable.
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  • 92
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    Differential method for the determination of the order of reaction and the rate constants (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 535-541 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is proposed whereby the orders and rate constants for processes obeying the rate law -dA/dt = kAn may be determined. The method is illustrated in two ways. First, simulated data for processes of various orders are treated, and the treatment is shown to be capable of reproducing orders and rate constants to a high degree of accuracy. The factors affecting the accuracy with which n and k can be determined are considered. These are inaccuracy in the determination of concentration values, irregularity of the time intevals between concentration determinations, and the length of those time intervals. It is shown that if concentrations are determined at times that are close together, the effect of the other two factors is small, but if the time intervals are made longer, the errors due to the other two factors affect the calculated values of n and k much more seriously. Second, the method was applied to two homogeneous reactions, of which one was first-order and one was second order, and three heterogeneous reactions, of which one was found by the original workers to be first order, one to be zero order, and one to vary between zero and first order, depending on the initial pressure. The present method gives results in agreement with these conclusions and reproduces the rate constants to within ±5% in all cases.
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  • 93
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    F-to-HF reactions. VIII. Nonthermal complications for the CHF3/C3F6/C2F6 moderated nuclear recoil system (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 565-583 
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    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Results are reported from moderated nuclear recoil 18F experiments with the 273 K CHF3/C3F6/C2F6 system. Although the measurement sensitivity is only about ±12%, there is no evidence to support the occurrence of nonthermal F-to-HF reactions at 95 mol % C2F6 moderator concentration.
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    Quantized RRK theory of unimolecular reaction rates (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 543-564 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The main difference between the simple RRK theory and the better based but more complex RRKM theory is explained. Starting from the premise that the classical versus quantum mechanical estimation of the density of states is the major source of the difference, earlier attempts to incorporate the quantum effects in an effective value for the number of oscillators s are noted. By examining the expression for the RRKM rate coefficient it is found that a single effective s value will generally not suffice, but a much better representation of the quantum effects can be obtained if it is recognized that the problem inherently contains two different effective s values. A theory based on this analysis is constructed. It reproduces RRKM results to much improved accuracy, removing difficulties found earlier with single-s-value theories.
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  • 95
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    Very low-pressure pyrolysis (VLPP) of pentynes. III. Pent-2-yne. Heat of formation and resonance stabilization energy of the 3-methylpropargyl radical (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 613-621 
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    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal unimolecular decomposition of pent-2-yne has been studied over the temperature range of 988-1234 K using the technique of very low-pressure pyrolysis (VLPP). The main reaction pathway is C4—C5 bond fission producing the resonance-stabilized 3-methylpropargyl radical. There is a concurrent process producing molecular hydrogen and penta-1,2,4-triene presumably via the intermediate formation of cis-penta-1,3-diene. The 1,4-hydrogen elimination from cis-penta-1,3-diene is the rate-determining step in the molecular pathway. This is supported by an independent VLPP study of cis- and trans-penta-1,3-diene. RRKM calculations show that the experimental rate constants for C—C bond fission are consistent with the following high-pressure rate expression at 1100 K: \documentclass{article}\pagestyle{empty}\begin{document}$$\log k_1 = \left({s^{ - 1}} \right) = \left({16.0 \pm 0.3} \right) - \left({72.6 \pm 2.0} \right)/\theta $$\end{document} where θ = 2.303RT kcal/mol and the A factor was assigned from the results of shock-tube studies of related alkynes. The activation energy leads to ΔHf,3000[CH3C≡CĊH2] = 70.3 and DH3000[CH3CCCH2—H] = 87.4 kcal/mol. The resonance stabilization energy of the 3-methylpropargyl radical is 10.6 ± 2.5 kcal/mol, which is consistent with previous results for this and other propargylic radicals.
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    URL: http://dx.doi.org/10.1002/kin.550140603
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  • 96
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    Chemiluminescence simulation method for the evaluation of the termination rate constant for 2-cyanopropyl peroxy and α-phenyl-ethyl peroxy radicals (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 641-646 
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    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An iterative method has been devised for the simulation of chemiluminescence data during the oxidative decomposition of αα′ azobisisobutyronitrile in the presence of ethylbenzene. From this simulation the cross termination rate constant of the two types of peroxy radicals present has been estimated.
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    URL: http://dx.doi.org/10.1002/kin.550140606
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  • 97
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    The liquid-phase reaction of CCl3 radicals with primary alcohols (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 659-668 
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    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of gamma-radiation-induced free-radical reactions in carbon tetrachloride solutions of ethanol and n-pentanol were studied in the range of 0.05-0.80M and 25-170°C. The rate constant for the reaction \documentclass{article}\pagestyle{empty}\begin{document}$${\rm CCl}_{\rm 3} + {\rm R} - CH_2 - {\rm OH}\mathop \to \limits^{k1} {\rm CHCl}_{\rm 3} + {\rm R} - {\rm CH} - {\rm OH}$$\end{document} was found as \documentclass{article}\pagestyle{empty}\begin{document}$$k1(M^{- 1} \cdot s^{- 1}) = 10^{8.6 \pm 0.4} \exp - (\frac{{9900 \pm 600{\rm cal}}}{{RT}})$$\end{document} The activation energy is larger by 0.8 kcal/mol than for secondary alcohols, while the A1 factors are about the same.
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    Ozone-isoprene reactions: Product formation and aerosol potential (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 955-975 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dark-phase experiments between isoprene and O3 are discussed. UNC outdoor chamber experiments have shown that in high-concentration systems of isoprene and O3 (5 ppm C and 1 ppm) approximately 75% of the reacted carbon can be observed in the product formation of HCHO, CO, methacrolein, methylvinylketone, methylglyoxal, acetaldehyde, and propylene. Mechanisms were developed which gave reasonable fits to dark-phase chamber experiments of MACR, MVK, isoprene, and O3. Experimental data and modeling results were used to generate O3 rates of attack on MVK and MACR. An isoprene-O3 rate of 1.67 × 10-2 ppm-1·min-1 was used and is consistent with other rates reported in the literature. Dark isoprene-O3 systems appear to form homogeneously nucleated aerosol. Most of these particles appear and remain at diameters well below the optical cutoff region (0.3-0.5 μm), as opposed to the particles from similar α-pinene-O3 systems, which also form at smaller sizes but then grow into the optical size range (0.5 μm). Lower concentrations of α-pinene and O3 (0.2 ppm C and 0.12 ppm) still generated substantial aerosol, but by comparison, rapid CN nucleation was not observed during a similar side-by-side system of isoprene and O3.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550140902
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  • 99
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    Kinetics and mechanism of reaction of p-methoxystyrene and tetracyanoethylene. I. Evidence for competitive 1,2- and 1,4-cycloadditions (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 985-996 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Time-resolved absorption spectra for a reaction mixture of p-methoxystyrene and tetracyanoethylene (TCNE) are found to have a band maximum at 325 nm which is assigned to the 1,4-cycloadduct. The reaction in chloroform at 15, 20, and 25°C is followed by the charge-transfer band at 600 nm. The 1,4-cycloadduct, besides the so far known 1,2-cycloadduct and EDA complex, is taken into account to derive the rate equation for the EDA complex that is a linear second-order differential equation. The rate constants for the elementary steps involved in the reaction are obtained. The 1,4-cycloaddition has an activation entropy of -63 J/K·mol for the cycloreversion and a reaction constant ρ of -4.7, both of which indicate the polar transition state. On the other hand, activation entropy of the 1,2-cycloaddition is 73 J/K·mol more negative than that of the 1,4-cycloaddition, supporting the zwitterionic mechanism for the 1,2-cycloaddition.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550140904
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  • 100
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    Electronic Resource
    Kinetics and mechanisms of the reaction of acetylene with cyclohexa-1,3-diene and the decomposition of bicyclo[2.2.2]-octa-2,5-diene in the gas phase (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 997-1005 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of acetylene (A) with cyclohexa-1,3-diene (CHD) has been studied between 450 and 592 K. The pressures of A ranged from 25 to 112 torr and those of CHD from 8 to 62 torr. The reaction yields only ethene (E) and benzene (B) instead of bicyclo[2.2.2]octa-2,5-diene (BOD), the product that is expected for a 1,4,1′,2′ addition of the Diels-Alder type. It is first order with respect to each reagent. The rate constant (in L/mol·s) is given by \documentclass{article}\pagestyle{empty}\begin{document}$$\log _{10} k = - (27,150 \pm 120)/4.576T + (7.49 \pm 0.05)$$\end{document} The thermal decomposition of BOD has also been studied. In the ranges of 354-435 K and 0.5-6 torr, the reaction is first order and results in the formation of equal amounts of B and E as the reaction of A with CHD does. Its rate constant (in s-1) is given by \documentclass{article}\pagestyle{empty}\begin{document}$$\log _{10} k_d = - (32,520 \pm 40)/4.576T + (14.06 \pm 0.02)$$\end{document} The following consecutive reactions are proposed for the reaction between A and CHD: where BOD is the primary product that is too unstable to be detected. This implies that the rate constant k is equal to ka. The reaction mechanisms and the strain energy in BOD are discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550140905
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