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  • 2000-2004  (21)
  • 1985-1989  (4.843)
  • 1975-1979  (5.105)
  • Inorganic Chemistry  (7.178)
  • Atomic, Molecular and Optical Physics  (1.864)
  • Electron microscopy  (927)
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  • 1
    Digitale Medien
    Digitale Medien
    Evidence of M cells as portals of entry for antigens in the nasopharyngeal lymphoid tissue of humans (2000)
    Springer
    Virchows Archiv 436 (2000), S. 560-566 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Key words M cell ; HRP ; Nasopharyngeal lymphoid tissue ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The nasopharyngeal tonsils (adenoids) are prominent components of human nasal-associated lymphoid tissues (NALT). However, the role of the nasopharyngeal tonsils in antigen uptake for initiation of the mucosal immune response is unknown. The aims of this study were to describe the ultrastructure and function of the M cells of the human nasopharyngeal tonsils and to clarify their capacity for antigen uptake. Tissues obtained from eight patients undergoing adenectomy were examined by light and electron microscopy. Lymphoepithelium covers the nasopharyngeal lymphoid tissue and consists of ciliary epithelium, non-ciliary epithelial cells, M cells, goblet cells, and many intraepithelial lymphoid cells. M cells have irregular and broad cytoplasm-containing microvilli on their surface and small vesicles in their cytoplasm. Many lymphoid cells were enfolded by M cells. The uptake of horseradish peroxidase (HRP) in the tissue in organ culture was studied using histochemical techniques. Excised adenoid tissue was incubated in RPMI 1640 culture media with HRP for 10, 30, and 60 min. HRP which had adhered to the surface was taken up in vesicles and then transported in vesicles and tubules by M cells. The M cells of nasopharyngeal lymphoid tissue were ultrastructurally and functionally similar to those in human Peyer’s patches and colonic lymphoid follicles. These findings indicate that NALT bears similarities to the gut-associated lymphoid tissue, and its antigen uptake capacity may be important for initiation of immunity in the upper aerodigestive tract.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004289900177
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  • 2
    Digitale Medien
    Digitale Medien
    Unusual prostatic adenocarcinoma with endocrine basophilic FSH-immunoreactive cells (2000)
    Springer
    Virchows Archiv 436 (2000), S. 628-633 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Key words Prostate adenocarcinoma ; Endocrine cells ; Immunohistochemistry ; FSH ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report an unusual variant of prostatic adenocarcinoma with marked endocrine differentiation (mixed endocrine-exocrine adenocarcinoma). Endocrine cells accounted for 60% of the tumour cells, were positive with silver impregnation and for chromogranin A, synaptophysin, and neuron-specific enolase, and coexpressed the exocrine antigens prostatic acid phosphatase and prostatic-specific antigen. Most of the endocrine cells were basophilic with haematoxylin-eosin and proved immunoreactive for alpha subunit of human chorionic gonadotropin and follicle-stimulating hormone. The remaining endocrine cells were represented by eosinophilic cells positive for serotonin, and by calcitonin and serotonin-immunoreactive cells not identifiable in haematoxylin-eosin-stained sections. On ultrastructural analysis, two types of endocrine cells were identified. The most frequent cell type showed abundant cytoplasmic round, electron-dense neurosecretory granules, either small (212±44 nm) or large (471±114 nm), resembling those of gonadotropic pituitary cells. The second type of endocrine cells contained irregular electron-dense granules similar to those of serotonin-storing enterochromaffin cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004289900163
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  • 3
    Digitale Medien
    Digitale Medien
    Ectopic calcification following tibial fracture: property analysis (2000)
    Springer
    Skeletal radiology 29 (2000), S. 609-612 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Keywords Ectopic calcification ; Deep posterior compartment syndrome ; Computed tomography ; Carbonate-containing apatite ; Electron microscopy ; X-ray diffraction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We present a patient whose ectopic calcification following deep posterior compartment syndrome was studied by electron microscopy, chemical analyses, and X-ray diffraction. The patient complained of a toe flexion deformity following a tibial fracture which he sustained 18 years earlier. Damage to the peroneal artery was demonstrated by magnetic resonance angiography, suggesting that the patient had had deep posterior compartment syndro-me in the past. A large radiopaque mass, identified in the flexor hallucis longus muscle by radiographs and computed tomography, was resected, resulting in a dramatic improvement of the toe deformity. The resected material was analyzed in detail. It included no osseous tissue, and was not birefringent under a polarizing microscope, being compatible with ectopic calcification rather than ossification. On electron microscopy the material was found to be an assembly of tiny rods. Chemical and X-ray diffraction analyses suggested a carbonate-containing apatite as the most probable substance.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560000267
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  • 4
    Digitale Medien
    Digitale Medien
    Defect structure of the low temperature α-cristobalite phase and the cristobalite ⇆ tridymite transformation in (Si-Ge)O2 (2000)
    Springer
    Physics and chemistry of minerals 27 (2000), S. 386-397 
    Details
    ISSN: 1432-2021
    Schlagwort(e): Key words Cristobalite ; Tridymite ; Phase transformation ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik
    Notizen: Abstract Using minimum exposure techniques, it is feasible to perform high resolution electron microscopy on the α-cristobalite phase of (Si0.9 Ge0.1)O2, which is extremely radiation sensitive. Such images reveal atomic scale information of twins and tridymite-like stacking faults on (1 1 1)β planes, as well as of domain boundaries resulting from the β→α transition. Polytype structures are formed in certain cases. Morphological features suggest that the phase transformation cristobalite → tridymite proceeds by means of a zonal dislocation mediated synchro-shear process on (1 1 1)β planes; the geometry of this process is analyzed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002699900082
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  • 5
    Digitale Medien
    Digitale Medien
    Papillary glioneuronal tumour: clinicopathological and biochemical study of one case with 7-year follow up (2000)
    Springer
    Acta neuropathologica 99 (2000), S. 321-326 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Papillary ; Glioneuronal tumour ; Electron microscopy ; NCAM ; L1 adhesion molecule
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Among the mixed glioneuronal tumours, a new variant called papillary glioneuronal tumour has recently been delineated. A case occurring in a 23-year-old man is reported. The tumour was cystic with a mural nodule enhanced by gadolinium injection. It was located within the left parieto-occipital lobe. Surgical excision showed a greyish friable tumour with cystic areas. Histopathological examination revealed a pseudopapillary component comprising a single layer of regular cells, arranged around hyalinised vessels. These cells were immunoreactive with anti-glial fibrillary acidic protein and HNK1 antibodies. A neurocytoma-like component coexisted with round blind cells and focal fibrillary rosettes. These cells were immunostained by anti-neuron-specific enolase and anti-synaptophysin antibodies. Neither mitoses nor ganglioid cells were seen. HNK1, the three isoforms of NCAM, and the L1 adhesion molecule were detected by Western blot analysis. Ultrastructural study showed three different types of cells. The first contained gliofilaments, the second showed long processes with true synapses, and the third was poorly differentiated. However, all had identical nuclei and contained dense bodies. These findings suggest a common origin for the tumour cells derived from a bipotential neuroglial progenitor. As for other mature mixed neuroglial tumours, the prognosis is good. Our patient is free of disease 7 years after complete surgical treatment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/PL00007445
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  • 6
    Digitale Medien
    Digitale Medien
    Indocyanine green (ICG) and laser irradiation induce photooxidation (2000)
    Springer
    Archives of dermatological research 292 (2000), S. 404-411 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Key words Fluorescence ; Photodynamic therapy ; Bromosulphophthalein ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The cellular uptake and subcellular localization of indocyanine green (ICG; absorption band 700– 850 nm), and cell survival and ultrastructural changes following ICG-mediated phototherapy were investigated in vitro in four different cell lines derived from human skin (SCL1 and SCL2 squamous cell carcinoma, HaCaT keratinocytes and N1 fibroblasts). The cellular uptake of ICG (1–50 μM, incubation times 1, 4, 24 h) was saturable, highly cumulative and could be inhibited by the addition of 250 μM bromosulphophthalein indicating the involvement of the organic anion transporting polypeptide (OATP). For HaCaT cells, the maximum cellular uptake (Vmax) and the Michaelis constant (Km) were 9.9 ± 1.1 mM and 47 ± 16 μM, respectively, following a 24-h incubation with ICG. Fluorescence microscopy revealed a cytoplasmic distribution of ICG, probably bound to glutathione S-transferase. Following irradiation with a cw-diode laser (805 nm, 80 mW/cm2) at doses of 24 or 48 J/cm2, the phototoxicity was determined using the MTT assay as a measure of cell viability. For all cell lines, ICG concentrations above 25 μM produced a significant phototoxic effect. The EC50 of ICG for HaCaT cells following irradiation at 24 J/cm2 was 20.1 ± 3.9 μM. Growth curves showed that even HaCaT cells treated at the EC50 were killed within a week following treatment. Electron microscopy 1 h after ICG-mediated phototherapy revealed cytoplasmic vesiculation, dilation of the rough endoplasmic reticulum, the Golgi complex and the perinuclear cisternae and the beginning of chromatin condensation in the nucleus. These ultrastructural findings are not consistent with a photothermal action of ICG-mediated phototherapy. Taken together with those of previous studies by our group these results support photooxidation as a major cell-killing mechanism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004030000147
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  • 7
    Digitale Medien
    Digitale Medien
    Comparative morphometric evaluation of peripheral nerves and muscle fibers in myotonic dystrophy (2000)
    Springer
    Acta neuropathologica 99 (2000), S. 39-47 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Sural nerve ; Muscle fiber diameter ; Morphometry ; Electron microscopy ; Myotonic ¶dystrophy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We compared peripheral nerve fibers and muscle fibers in myotonic dystrophy (MD) using a computer-assisted device for morphometry. In the 17 cases with MD studied, the sural nerves of 14 cases (82%) showed various degrees of reduction of the myelin sheath area (MSA) per endoneurial area. Of these, 8 cases (47%) presented with a mild reduction of the MSA, 5 cases (29.4%) with moderate reduction, and one case (6%) with severe reduction. The number of myelinated nerve fibers was not significantly reduced in MD when compared with control nerves, due to clusters of small regenerated nerve fibers. The mean diameter of the muscle fibers in 6 of the 17 cases was less than 40 μm. Of these 6 severely affected cases, ¶5 revealed a considerable reduction of the MSA. Other cases, which appeared to be normal in respect to the diameter of muscle fibers, showed various degrees of reduction of the MSA. Thus, there is usually, but not always a morphometric correlation of the severity of changes between peripheral nerves and muscle. The severity of the peripheral neuropathy appears to depend largely on the patient’s age, the stage of the disorder, and the time of progression. Electron microscopic examination of sural nerves showed significant, though non-specific pathological changes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/PL00007404
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  • 8
    Digitale Medien
    Digitale Medien
    Tubulovesicular particles occur early in the incubation period of murine scrapie (2000)
    Springer
    Acta neuropathologica 99 (2000), S. 525-528 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Tubulovesicular particles ; Scrapie ; Electron microscopy ; Prion protein ; Transmissible ¶spongiform encephalopathy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Tubulovesicular bodies are structures, apparently specific to the transmissible spongiform encephalopathies, which are of unknown composition and significance. Prion protein (PrP) is absent from tubulovesicular bodies when tissues are examined by immunogold electron microscopy. In the F1 cross of C57 and VM mice (CVF1) infected with ME7 scrapie there is a marked degeneration of hippocampal CA1 neurons. In this model the earliest changes seen, at about 100 days post inoculation (dpi) are a degeneration of axon terminals and synaptic loss. Terminal disease is around 250 dpi. In blind coded trials we counted the number of tubulovesicular particles and estimated their density in 56–76 electron micrographs taken from the stratum radiatum of each of one or two CVF1 ME7-infected mice at 84, 100, 126, 154 and 181 dpi and from four normal brain inoculated control mice. Tubulovesicular particles were present from 98 dpi and the density of particles increased with increasing incubation period. The very early occurrence of tubulovesicular particles, before the presence of significant pathology, argues that tubulovesicular particles are a part of the primary disease and are not epiphenomena.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010051155
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  • 9
    Digitale Medien
    Digitale Medien
    The need for a shared database infrastructure: combining X-ray crystallography and electron microscopy (2000)
    Springer
    European biophysics journal 29 (2000), S. 457-462 
    Details
    ISSN: 1432-1017
    Schlagwort(e): Key words X-ray crystallography ; Electron microscopy ; Biological databases
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Physik
    Notizen: Abstract Advances in structural biology are opening greater opportunities for understanding biological structures from the cellular to the atomic level. Particularly promising are the links that can be established between the information provided by electron microscopy and the atomic structures derived from X-ray crystallography and nuclear magnetic resonance spectroscopy. Combining such different kinds of structural data can result in novel biological information on the interaction of biomolecules in large supramolecular assemblies. As a consequence, the need to develop new databases in the field of structural biology that allow for an integrated access to data from all the experimental techniques is becoming critical. Pilot studies performed in recent years have already established a solid background as far as the basic information that an integrated macromolecular structure database should contain, as well as the basic principles for integration. These efforts started in the context of the BioImage project, and resulted in a first complete database prototype that provided a versatile platform for the linking of atomic models or X-ray diffraction data with electron microscopy information. Analysis of the requirements needed to combine data at different levels of resolution have resulted in sets of specifications that make possible the integration of all these different types in the context of a web environment. The case of a structural study linking electron microscopy and X-ray data, which is already contained within the BioImage data base and in the Protein Data Bank, is used here to illustrate the current approach, while a general discussion highlights the urgent need for integrated databases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002490000089
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  • 10
    Digitale Medien
    Digitale Medien
    Ultrastructure and innervation of regenerated intrafusal muscle fibres in heterochronous isografts of the fast rat muscle (2000)
    Springer
    Acta neuropathologica 100 (2000), S. 435-444 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Muscle transplantation ; Muscle ¶regeneration ; Electron microscopy ; Muscle spindles ; Motor innervation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Extensor digitorum longus (EDL) muscles from 2- to 28-day-old rats were grafted into EDL muscles of adult inbred recipients (n = 8). At 1–6 months after the operation, experimental muscles were excised and the ultrastructure and innervation of regenerated muscle spindles was examined. Regenerated muscle spindles (n = 36) in isografted EDL muscles contained 4.3 ± 0.2 (mean ± SEM) encapsulated muscle fibres. These “intrafusal” muscle fibres lacked nuclear bag and nuclear chain accumulations, which are characteristic of normal muscle spindles; thus, they rather resembled thin encapsulated extrafusal muscle fibres. In the same sample, myelinated axons were found in 33 (92%) muscle spindles, but no sensory terminals were found. These findings demonstrate that regenerated spindles in isografted EDL muscles were not reinnervated by spindle-specific sensory axons, but exclusively by motor axons. Typical intracapsular motor endplates (MEPs) were found in one third of regenerated spindles examined. Their motor terminals contained accumulated mitochondria and synaptic vesicles. As is characteristic for MEPs, axolemma and sarcolemma were separated by a synaptic cleft about 60 nm wide that contained a basal lamina. The underlying sarcolemma formed either small infoldings or none at all, and the subsynaptic area contained only small subsarcolemmal accumulations of mitochondria. It is apparent that the structures described here as “regenerated muscle spindles” do not perform their normal physiological function as stretch receptors because they lack the sensory innervation. The present results show that regeneration and reinnervation in heterochronous isografts corresponds to that previously described in autotransplanted free muscle grafts. The results also show that, during muscle spindle regeneration, intrafusal satellite cells develop into extrafusal-like muscle fibres, apparently due to their motor innervation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010000194
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  • 11
    Digitale Medien
    Digitale Medien
    Evidence for stable grain boundary melt films in experimentally deformed olivine-orthopyroxene rocks (2000)
    Springer
    Physics and chemistry of minerals 27 (2000), S. 480-494 
    Details
    ISSN: 1432-2021
    Schlagwort(e): Key words Olivine ; Grain boundary ; Partial melt ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik
    Notizen: Abstract The microstructure of olivine-olivine grain boundaries has been studied in experimentally deformed (1200–1227 °C, 300 MPa) partially molten olivine and olivine-orthopyroxene rocks. In-situ melting produced ∼1 vol% melt in all samples studied. Grain boundary analyses were carried out using a number of transmission electron microscopy techniques. The grain boundary chemistry in undeformed olivine-orthopyroxene starting material showed evidence for the presence of an intergranular phase along some, but not all, of the olivine-olivine boundaries. In the deformed samples, ultrathin Si-rich, Al- and Ca-bearing amorphous films have been observed along all investigated olivine-olivine grain boundaries. The chemistry of the grain boundaries, which is considered to be indicative for the presence of a thin film, was measured with energy-dispersive X-ray spectroscopy (EDX) and energy-filtering imaging. The amorphous nature of the films was confirmed with diffuse dark field imaging, Fresnel fringe imaging, and high-resolution electron microscopy. The films range in thickness from 0.6 to 3.0 nm, and EDX analyses show that the presence of Al and Ca is restricted to this ultrathin film along the grain boundaries. Because thin melt films have been observed in all the samples, they are thought to be stable features of the melt microstructure in deformed partially molten rocks. The transition from the occasional presence of films in the undeformed starting material to the general occurrence of the films in deformed materials suggests that deformation promotes the formation and distribution of the films. Alternatively, hot-pressing may be too short for films to develop along all grain boundaries. A difference in creep strength between the studied samples could not be attributed to grain boundary melt films, as these have been found in all deformed samples. However, a weakening effect of grain boundary melt films on olivine rheology could not be ruled out due to the lack of confirmed melt-film free experiments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002690000090
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  • 12
    Digitale Medien
    Digitale Medien
    Surface changes in the rat vomeronasal epithelium during degeneration and regeneration of sensory receptor cells (2000)
    Springer
    Anatomy and embryology 201 (2000), S. 467-473 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Key words Pheromone ; Supporting cell ; Vomeronasal organ ; Olfaction ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  To investigate cell turnover in the vomeronasal epithelium we used electron microscopy to obtain quantitative measurements of changes observed at the surface of the sensory epithelium. Receptor cell degeneration was induced by sensory nerve transection and animals were examined at postoperative recovery times of 2, 4, 6, 10, 15, 35 and 60 days. We measured the number and density of receptor and supporting cells, and membrane length at the surface of the sensory epithelium. The number of receptor cells rapidly decreased during the degeneration period, reaching a minimum at 6 days. After 15 days of recovery the number and density of receptor cells returned to control levels. The surface membrane length for regenerated receptor cells was similar to that of controls, however the morphological appearance was characteristic of immature cells. In contrast to the receptor cells, the number and density of supporting cells did not change during degeneration and regeneration. However, there was a significant increase in the length of supporting cell-surface membranes. These results suggest that during receptor cell degeneration, supporting cell membranes compensate for the loss of receptor cells by expanding their surface membrane length to help to maintain the continuity of the epithelial surface. Thus, an important role of vomeronasal supporting cells may be to maintain the structural integrity of the epithelium during turnover of the receptor cell population.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004290050333
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  • 13
    Digitale Medien
    Digitale Medien
    Gastrointestinal pacemaker cell tumor: clinicopathological, immunohistochemical, and ultrastructural study with special reference to c-kit receptor antibody (2000)
    Springer
    Virchows Archiv 436 (2000), S. 234-242 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Key words Gastrointestinal pacemaker cell tumor ; Interstitial cells of Cajal ; Gastrointestinal autonomic nerve tumor ; c-kit Receptor-antibody ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Recent studies indicate that a subgroup of gastrointestinal stromal tumors, including gastrointestinal autonomic nerve tumors (GANTs), originate from stem cells that differentiate toward a pacemaker-cell phenotype. These pacemaker cells form a complex network intercalated between the autonomic nerves and the muscle walls of the gastrointestinal tract and are called interstitial cells of Cajal (ICC). The c-kit receptor (CD117) is a sensitive marker for ICC. The aim of our study was to support the hypothesis that GANTs show ICC differentiation. Seven GANTs without convincing smooth muscle or neural differentiation all showed homogeneous reactivity for the c-kit receptor. CD34 was positive in three cases. On electron microscopy, the typical features of GANT were present. Six tumors contained skeinoid fibers. Most tumors were related to the small bowel. They presented as single (two cases) or multiple (five cases) tumors. The presenting symptoms were abdominal bleeding (2), abdominal mass (2), anemia (1), and small-bowel perforation (1). In two cases, liver metastases developed. Because of the close immunohistochemical and electron microscopic similarities of these tumors to the interstitial cells of Cajal, the term gastrointestinal pacemaker cell tumor seems appropriate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004280050036
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  • 14
    Digitale Medien
    Digitale Medien
    A back-scattered electron microscopy (BSEM) study of the tight apposition between bone and hydroxyapatite coating (2000)
    Springer
    Journal of orthopaedics and traumatology 1 (2000), S. 11-16 
    Details
    ISSN: 1590-9999
    Schlagwort(e): Key words Hydroxyapatite ; Bone ; Interface ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We performed a back-scattered electron microscopy analysis of the interface between newly formed bone and hydroxyapatite coating, in an experimental rabbit model. Twenty cylinders made of Ti6A14V and coated with hydroxyapatite at different crystallinity were implanted in the distal femural canal and retrieved at 4, 8, 26 an 34 weeks. Crystallinity of the coating varied from 90% to 60% and thickness varied between 50 and 100 μm. Osteocytes were detectable a few micrometers in proximity of the coating. They produced new bone which was so tightly apposed to the coating that high magnification BSEM did not resolve any discontinuity at the interface. This was not observed in uncoated implants. Degradation of the hydroxyapatite coating is not a simple hydrolytic process because newly formed bone is remodelled in areas were a tight apposition with hydroxyapatite is present. The coatint itself is likely to be attacked by the resorptive action of multinucleated giant cells and osteoclasts. In conclusion, response to coated samples is morphologically characterized by tight apposition with bone. The substitution of areas of the coating by newly formed bone is possible.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/PL00012192
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  • 15
    Digitale Medien
    Digitale Medien
    Neuronal ceroid lipofuscinoses: pathological features of bioptic specimens from 28 patients (2000)
    Springer
    Neurological sciences 21 (2000), S. S63 
    Details
    ISSN: 1590-3478
    Schlagwort(e): Key words NCLs ; Peripheral biopsies ; Brain biopsy ; Blood lymphocytes ; Electron microscopy ; Pathological cytosomes ; Diagnostic criteria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Clinical findings and pathological features of 28 patients affected with neuronal ceroid lipofuscinoses (NCL) are reviewed. The patient group included 15 children affected with the late-infantile form of NCL (LINCL), 10 patients affected with the juvenile form (JNCL), and 3 adult cases. Ultrastructural examinations of 50 biopsies from 6 tissues were consistent with clinical features in all LINCL and JNCL cases but one. The importance of electron microscopic (EM) examination of blood lymphocytes in these forms is outlined, particularly when combined with molecular analysis of the CLN2 or CLN3 genes, respectively. This approach leads to a definite diagnosis of LINCL and JNCL is a relatively short time. In adult NCL, diagnosis still relies on pathological grounds, and difficulties in interpreting the osmiophilic storage bodies in different tissues are outlined. EM investigation of blood lymphocytes was not helpful in any case of adult NCL. Results of one stereotactic brain biopsy are also reported.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s100720070042
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  • 16
    Digitale Medien
    Digitale Medien
    Effects of photic and thermal stress on distal and proximal rhabdomeres in the crayfish eye: why are the visual membranes of the 8th retinula cell more resilient than the others? (2000)
    Springer
    Protoplasma 210 (2000), S. 156-163 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Electron microscopy ; Photoreceptor ; Visual membrane ; Photic radiation damage ; Retina ; Crustacea
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Visual membranes of the crayfish eye either belong to the small, distally placed rhabdomere of retinula cell R8 or are part of the much more voluminous proximal rhabdom, made up of rhabdomeres belonging to cells R1–R7. Under various conditions of environmental stress (e.g., prolonged darkness, elevated temperature, bright light with and without a concomitant rise in temperature, flickering lights) the visual membranes of R8 prove far more resistant to structural damage than those of R1–R7. Membrane damage is known to occur when dormant lipoxygenases become activated, for example through heat. Since R8 is the only type of visual cell in the crayfish retina that does not contain grains of screening pigment, the view that screening-pigment granules could “aggravate” or even “trigger” membrane damage in times of stress is strengthened. Functionally, R8's strong resistance to physical damage when exposed to flickering lights points to a role of the distal rhabdom in the movement detection system of the crayfish eye.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01276855
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  • 17
    Digitale Medien
    Digitale Medien
    Biocompatibility of MPC: in vivo evaluation for clinical application (2000)
    Springer
    Journal of artificial organs 3 (2000), S. 39-46 
    Details
    ISSN: 1619-0904
    Schlagwort(e): Poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (MPC) ; In vivo biocompatibility ; Artificial endocrine pancreas ; Electron microscopy ; Glucose sensor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin , Technik allgemein
    Notizen: Abstract Biocompatibility is important to assure a mild body reaction to an implanted device and its long-term stability and functionality. In diabetes research, subcutaneously implanted glucose monitoring systems need biocompatible surfaces for long-term application. The biocompatibility of poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (MPC), a material similar to the phospholipid layer of a cell membrane, was compared in vivo with the biocompatibility of polyurethane (PU), polyvinyl alcohol (PVA), and cuprophane (CUP). Needle-type glucose sensors and hollow-fiber probes used for microdialysis were coated with these four different biomaterials and implanted subcutaneously in 18 rats and 7 healthy volunteers. At set intervals, the implants and, in the case of the rats, also the surrounding tissue were removed and characterized by light and electron microscopy. MPC-coated sensors and hollow-fiber probes showed smooth and thin deposits in flat layers, whereas the surface deposits on PU- and PVA-coated sensors and those on CUP hollow-fiber probes appeared as rough, irregular, and dense attachments of aggregated cells and protein. This study confirmed results from earlier in vitro tests by showing the biocompatibility and reliability of MPC. Even though the amount of protein and cells attached to the MPC surface was not as low as expected from in vitro experiments, the biocompatibility and long-term stability of the implanted devices were superior to those of PU, PVA, and CUP.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02479925
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  • 18
    Digitale Medien
    Digitale Medien
    Chordoid meningioma (2000)
    Springer
    Brain tumor pathology 17 (2000), S. 153-157 
    Details
    ISSN: 1861-387X
    Schlagwort(e): Chordoid meningioma ; Castleman syndrome ; Electron microscopy ; Immunohistochemistry ; Magnetic resonance image
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Chordoid meningioma is a relatively rare variant that is often associated with peritumoral lymphoplasmacellular infiltration causing Castleman syndrome (CS). We present a 44-year-old woman with chordoid meningioma not associated with CS. The patient presented with epilepsy and right hemiparesis (Todd's palsy) on admission. The radiological findings revealed an extraaxial mass lesion in the premotor cortex. They were compatible with a preoperative diagnosis of meningioma. No physical abnormalities related to CS were detected. A left frontal craniotomy was performed. The tumor surface was gelatinous, and it was totally resected with the attached dura mater (Simpson grade I). The patient had an uneventful recovery, and her seizures subsided. The pathological findings of the specimens revealed nests and cords of spindle and epithelioid cells with abundant myxoid matrix, mimicking the features of chordoma. On the basis of radiological, immunohistochemical, and electron microscopic findings, chordoid meningioma was verified, and a review of the literature was performed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02484287
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  • 19
    Digitale Medien
    Digitale Medien
    An ultrastructural study of pigmented purpuric dermatitis with special reference to fibrous long-spacing collagen (2000)
    Springer
    Medical electron microscopy 33 (2000), S. 39-43 
    Details
    ISSN: 1437-773X
    Schlagwort(e): Key words Pigmented purpuric dermatitis ; Endothelial cell ; Fibrous long-spacing collagen ; Intracellular structure ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A case of pigmented purpuric dermatitis (PPD) in a Japanese man aged 59 years is reported with an interesting ultrastructural finding. Clinically, the lesions, which consisted of telangiectatic puncta and pigmentation, were irregular in shape and occurred predominantly on the lower legs without pruritus. Histologically, lymphocytic perivascular infiltrates and extravasation of red blood cells were observed in the papillary dermis. Ultrastructurally, endothelial cells with ovoid nuclei showed swelling and the lumen of the capillary became narrowed. Several banded structures, so-called fibrous long-spacing collagen (FLSC), were observed in the cytoplasm. They were spindle shaped, about 5 μm in length, and showed crossbands of 300-nm-wide intervals with fine intraperiodic bands. These structures were not observed in dermal connective tissue and fibroblasts. These results suggested that FLSC was synthesized in endothelial cells rather than being phagocytosed by endothelial cells, which might be helpful in investigating the etiology of PPD.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s007950000006
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  • 20
    Digitale Medien
    Digitale Medien
    Investigation of titanium leak to bone tissue surrounding dental titanium implant: electron microscopic findings and analysis by electron diffraction (2000)
    Springer
    Medical electron microscopy 33 (2000), S. 96-101 
    Details
    ISSN: 1437-773X
    Schlagwort(e): Key words Dental titanium implant ; Electron microscopy ; X-ray microanalysis ; Electron diffraction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract This study investigated the tissue response associated with dental titanium implants. The mandibular third and fourth premolars and first molar of three adult beagle dogs were extracted bilaterally. Healing was then allowed for 3 months. Six titanium implants were placed in the mandibles of a dog. Three weeks after the implantation, mandibular sections containing the implants were retrieved with the use of a bone saw and investigated by light and electron microscopy, X-ray microanalyzer, and electron diffraction. Scanning electron microscopic observation showed titanium particles on the implant–bone interface, and investigation by microanalyzer revealed titanium not only on the implant–bone interface but also in the bone tissue. Transmission electron microscopic observation and investigation by electron diffraction showed titanium in the bone matrix and cells other than macrophages. In this study, titanium particles from the dental implant were recognized morphologically in the surrounding bone tissue. Thus, study of the influence of titanium particles on the human body is needed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s007950070008
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  • 21
    Digitale Medien
    Digitale Medien
    Morphologische und funktionelle Veränderungen der Nasenschleimhaut nach nCPAP-Therapie (2000)
    Springer
    HNO 48 (2000), S. 747-752 
    Details
    ISSN: 1433-0458
    Schlagwort(e): Schlüsselwörter Obstruktives Schlafapnoesyndrom ; nCPAP Therapie ; Nasenschleimhaut ; Elektronenmikroskopie ; Keywords Obstructive sleep apnea ; nCPAP-therapy ; Nasal mucosa ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract Background and objective. The treatment success of nCPAP therapy (nasal continuous positive airway pressure) depends partly on the relief of symptoms and partly on long-term patient acceptance and the related avoidance of complications.Nasal complaints constitute the most frequently reported side effects and, together with problems of mask application, are among the primary factors causing an nCPAP-therapy to be prematurely discontinued. Patients/Methods. To assess the morphological changes of the nasal mucosa during nCPAP-therapy, we excised specimens of nasal mucosa tissue in twelve patients with obstructive sleep apnea syndrome (OSAS) both before and 3–10 months after establishing nCPAP-mask acceptance. The specimens were examined by electron microscopy. Results. In all these patients, acceptance of the CPAP mask marked the initial part of therapy. In addition, mucociliary clearance was assessed by the saccharin test before and after therapy. In all patients, the nasal epithelium underwent fundamental changes upon CPAP therapy, which became manifest as modifications in the shape of epithelial cells, conglutination and clumping of the microvilli, and the appearance of immunocompetent cells. Once patients were nCPAP mask compliant, mucociliary clearance was distinctly prolonged in all cases. Conclusions. A successful therapeutic concept should provide normalization of room temperature and air humidity once nCPAP mask compliance has been achieved, and include regular assessment of the condition of the mucosa in the upper respiratory tract. Only by these measures can nasal complications be countered or therapy be applied at an early stage.
    Notizen: Zusammenfassung Hintergrund und Fragestellung. Der Therapieerfolg einer nCPAP-Therapie (“nasal continuous positive airway pressure”) ist einerseits abhängig von der Linderung der Beschwerden und andererseits von der Langzeitakzeptanz und der hiermit verbundenen Vermeidung von Komplikationen. Nasale Beschwerden sind die häufigsten Nebenwirkungen und neben den Maskenproblemen die wichtigste Ursache, weshalb eine nCPAP-Therapie frühzeitig unterbrochen wird. Patienten/Methodik. Wir haben bei 12 Patienten mit einem obstruktivem Schlafapnoesyndrom Probeexzisionen aus der Nasenschleimhaut vor und 3–10 Monate nach Anpasssung der nCPAP-Maske entnommen und elektronenmikroskopisch untersucht. Bei all diesen Patienten war die Anpassung der nCPAP-Maske die Ersttherapie. Darüber hinaus wurde vor und nach der Therapie die mukoziliäre Clearance mit Hilfe des Saccharintests beurteilt. Ergebnisse. Bei allen Patienten kam es nach der nCPAP-Therapie zur grundlegenden Veränderungen des Nasenepithels mit Veränderung der Epithelzellenform, Verklebungen und Verklumpungen der Mikrovilli und auftreten von immunkompetenten Zellen. In allen Fällen war die mukoziliäre Clearance nach Anpassung der nCPAP-Maske deutlich verlängert. Schlussfolgerungen. Ein erfolgreiches Therapiekonzept sollte die Normalisierung der Raumtemperatur und Luftfeuchtigkeit gleich nach der Anpassung der nCPAP-Maske und die regelmäßige Beurteilung der Schleimhautverhältnisse der oberen Atemwege beinhalten. Nur somit können nasale Komplikationen aufgehalten oder frühzeitig therapiert werden.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s001060050652
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  • 22
    Digitale Medien
    Digitale Medien
    Neural crest origin of clear cell sarcoma of tendons and aponeuroses (1989)
    Springer
    Virchows Archiv 415 (1989), S. 51-60 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Clear cell sarcoma ; Melanosomes ; Cytochemistry ; Electron microscopy ; Nude mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In order to clarify the histogenesis of clear cell sarcoma of tendons and aponeuroses (CCS), two cases of human and one nude mouse-transplanted CCS line were studied using an ultrastructural and enzyme cytochemical approach. Most of the tumour cells obtained from the primary and transplanted CCS demonstrated melanosomes in various stages of development within the cytoplasm, whereas no melanosomes could be identified in the metastatic CCS. However, cholinesterase and tyrosinase activities could be demonstrated not only in the melanotic primary and transplanted CCS but also in the amelanotic metastatic CCS. The results therefore support the hypothesis that CCS is a soft tissue tumour derived from the neural crest.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00718604
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  • 23
    Digitale Medien
    Digitale Medien
    An ultrastructural study of the hypertrophied human papillary muscle cell with special emphasis on specific staining patterns, mitochondrial projections and association between mitochondria and SR (1989)
    Springer
    Virchows Archiv 414 (1989), S. 187-198 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Human heart ; Papillary muscle ; Hypertrophy ; Mitochondria ; Specific staining ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Biopsy material of the hypertrophied human papillary muscle has been processed according to various electron microscopical techniques in order to study the mitochondrial ultrastructure and the association between mitochondria and sarcoplasmic reticulum (SR).En bloc staining with a Cu-Pb citrate solution resulted in specifically contrasted mitochondrial and sarcotubular membranes, characterized by numerous, discrete, electron-dense particles. The differences in staining patterns between the perinuclear mitochondria and their subsarcolemmal and interfibrillar counterparts suggest differences in chemical properties and/or metabolic activities. The selectively contrasted mitochondrial particles may represent a conglomorate of extrinisic and intrinisic respiratory enzymes and other membrane-associated proteins, while the majority of the electron-dense particles of the sarcotubular membrane may represent positively stained Ca2+-pumps. Ultrastructural findings in the present study strongly indicate that the slender mitochondrial projections represent an initial stage in a process leading to the formation of large and pleomorphic mitochondria. Intimate contact between adjacent mitochondria as well as between mitochondria and SR are documented. In the contact regions some of the specifically contrasted particles of the adjacent membranes had fused with each other. It is suggested that these particles represent membrane-bound transport proteins providing a system for interorganelle exchanges of metabolites and/or ions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00822022
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  • 24
    Digitale Medien
    Digitale Medien
    Carcinosarcoma of the urinary bladder (1989)
    Springer
    Virchows Archiv 415 (1989), S. 91-95 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Carcinosarcoma ; Urinary bladder ; Immunohistochemistry ; Electron microscopy ; Rhabdomyoblast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case of urinary bladder carcinosarcoma (UBCS) is reported with light, immunohistochemical and electron microscopical findings. The tumour consisted of a squamous cell carcinoma, variable spindle cell stromal elements compatible with fibrosarcoma, and rhabdomyoblasts. Intermediate filament co-expression of cytokeratin and vimentin was shown by immunohistochemistry. Electron microscopy (EM) confirmed the nature of the three components, and indicated some similarities between the three cell-types present. Comparisons with the previous UBCS in the literature are made.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00718608
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  • 25
    Digitale Medien
    Digitale Medien
    Immunocytochemical and morphometric analysis of acinar zymogen granules in human acute pancreatitis (1989)
    Springer
    Virchows Archiv 415 (1989), S. 115-124 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Human acute pancreatitis ; Zymogen granules ; Acinar cells ; Electron microscopy ; Immunocytochemistry ; Morphometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In the present study fine structural changes of acinar zymogen granules were investigated in human acute pancreatitis. Pancreatic tissue was obtained at surgery from 6 patients, prepared for ultrastructural analysis, and stained immunocytochemically for trypsinogen. Stereological parameters of zymogen granules were evaluated. The density of the immunocytochemical labelling for trypsinogen was estimated over zymogen granules, the rough endoplasmic reticulum, Golgi apparatus and the acinar lumina. In acute pancreatitis the number of zymogen granules was diminished and their size reduced. The density of the labelling for trypsinogen was unchanged over zymogen granules but showed a significant reduction over the rough endoplasmic reticulum, Golgi apparatus, and the acinar lumina. In general the integrity of zymogen granules was well preserved. Focally degenerative changes of zymogen granules and large autophagosomes were observed. From the immunogold labelling a disturbance of enzyme synthesis and secretion was suggested. Evidence is given that a disruption of the zymogen granule membranes and a fusion with lysosomal bodies might contribute to the pathogenesis of human acute pancreatitis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00784348
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  • 26
    Digitale Medien
    Digitale Medien
    Early bronchopulmonary lesions in rat lung after normobaric 100% oxygen exposure and their evolution (1989)
    Springer
    Virchows Archiv 414 (1989), S. 135-145 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Hyperoxia ; Lung broncho-vascular reaction ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In order to clarify the early phenomena involved in the lung reaction to hyperoxia, twenty adult male rats were exposed to 100% oxygen at 1 ATA. Morphological pulmonary lesions were detectable after only 24 h hyperoxia, and included vasoconstriction and perivascular oedema, bronchiolar constriction, and pericyte reaction. The lesions were irregularly scattered within the lung parenchyma and occurred preferentially in areas centred on bronchiolo-vascular stems. Even at the latest stages, pulmonary heterogeneity was obvious, from the coexistence of areas damaged at different times. Neuro-epithelial-bodies were found under the bronchiolar epithelium; the morphological aspect of the neuro-endocrine cells observed was consistent with hyperoxia-induced modulation of their secretory activity. Taken together, our findings show the speed of development of hyperoxia-induced pulmonary changes and raise some pathogenic considerations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00718593
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  • 27
    Digitale Medien
    Digitale Medien
    Ultrastructural and electron immunohistochemical features of medullary thyroid carcinoma (1989)
    Springer
    Virchows Archiv 414 (1989), S. 375-384 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Thyroid neoplasms ; Electron microscopy ; Immunohistochemistry ; Calcitonin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary An ultrastructural study, both morphological and immunohistochemical, has been carried out on eight thyroglobulin-positive and nine thyroglobulin-negative medullary carcinomas of the thyroid. The morphometric analysis of granule size showed that all tumours contained cells with small granules and cells with medium size granules, whereas eight tumours had additional cells with large granules. The small granules had an electron dense core, while the medium and large sized granules were both pale-cored and dense-cored. The cells with small, medium or large secretory granules were all immunoreactive for calcitonin and CGRP. No ultrastructural differences were observed between thyroglobulin-positive and thyroglobulin-negative cases of medullary carcinoma of the thyroid.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00718620
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  • 28
    Digitale Medien
    Digitale Medien
    Liver parenchymal cell parasitism in human visceral leishmaniasis (1989)
    Springer
    Virchows Archiv 415 (1989), S. 1-6 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Visceral leishmaniasis ; L. donovani ; Parasitism ; Liver pathology ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Liver parenchymal cell parasitism with the amastigotes form ofL. donovani was detected by electron microscopy in human visceral leishmaniasis. Endocytosis was considered to be the mechanism by which the leishmania entered the cell. Evidence of well preserved parasites within hepatocytes suggest this parasitism as a possible reservoir for recrudescence.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00718599
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  • 29
    Digitale Medien
    Digitale Medien
    An immunohistochemically defined non-Hodgkin's lymphoma showing intercellular junctions (1989)
    Springer
    Virchows Archiv 415 (1989), S. 297-300 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Non-Hodgkin's lymphoma ; Electron microscopy ; Immunohistochemistry ; Intercellular junction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A rare example of pleomorphic B cell non-Hodgkin's lymphoma is described in which tumour cells possessed simple intercellular junctions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00724918
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  • 30
    Digitale Medien
    Digitale Medien
    Collagen secretion granules in reactive stromal myofibroblasts, with preliminary observations on their occurrence in spindle cell tumours (1989)
    Springer
    Virchows Archiv 415 (1989), S. 437-445 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Collagen secretion granule ; Myofibroblast ; Spindle cell tumour ; Electron microscopy ; Diagnosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Collagen secretion granules, representing stages in the intracellular packaging, transport and secretion of collagen-fibril precursor, have been studied by transmission electron microscopy in non-neoplastic human myofibroblasts and in neoplastic cells from a preliminary study of tumours exclusively or partly of spindle cell type. Vesicles, newly separated from Golgi saccules and containing finely fibrillar material, were identified as early presecretory granules, the most immature type of granule. Later stages exhibited longitudinally arranged, densely fibrillar bundles. Subsequently, secretory granules developed more homogeneously dense content. Fibril-containing cisternae near the plasma membrane were interpreted as either endocytotic or lysosomal structures, or as participants in the final stages of secretion. The features by which collagen secretion granules can be distinguished from other Golgi products, in particular melanosomes, Weibel-Palade bodies and lysosomes, are pointed out. The significance of these organelles for cell identification and tumour diagnosis is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00747745
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  • 31
    Digitale Medien
    Digitale Medien
    Salivary gland myoepithelioma variants (1989)
    Springer
    Virchows Archiv 416 (1989), S. 25-42 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Salivary gland ; Myoepithelioma ; Neoplasm ; Electron microscopy ; Immunohistochemistry ; Cytoplasmic filaments
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The histological and ultrastructural features of five major salivary gland tumours, which have little or no evidence of duct- or gland-type differentiation in routine sections, are described. Four of the cases have the tumour cells organized as narrow, anastomosing cords of cells separated by a myxoid and vascularized stroma; we have designated such lesions as reticular-type myoepitheliomas. The fifth case has a solid growth pattern and is largely composed of hyaline cells, that is, a plasmacytoid myoepithelioma. Ultrastructurally, one reticular myoepithelioma reveals myoepithelial cell differentiation with microfilament aggregates, while the other three examples are composed of modified myoepithelial cells displaying widened intercellular spaces, prominent synthesis of extracellular glycosaminoglycans, distinct basal lamina development, and obvious accumulations of cytoplasmic intermediate filaments. In electron micrographs, the modified myoepithelial cells of the plasmacytoid variant closely resemble the tumour cells in the reticular form. Three cases had expression of both glial fibrillary acid protein (GFAP) and vimentin, but only one of the myoepitheliomas contained muscle-specific actin. At least focally, each of the cases exhibited a considerable spectrum of cytokeratin filaments. Using double-labeled immunofluorescent microscopy of one reticular variant and the plasmacytoid myoepithelioma, there was individual tumour cell co-expression of GFAP and vimentin focally in the plasmacytoid myoepithelioma, but co-expression of cytokeratins 13, 16 and GFAP were not noted in either case. As expected, co-expression of high- and low-molecular weight cytokeratin filaments was wide-spread in both myoepitheliomas. Most described myoepitheliomas have a solid growth pattern and are composed of spindle and plasmacytoid cells, but based on cytological features and growth patterns in this series, it is apparent that polygonalshaped cells with novel architecture can occur in myoepitheliomas. The results also indicate the close relationship between pleomorphic adenoma and such variants of myoepithelioma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01606467
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  • 32
    Digitale Medien
    Digitale Medien
    A histopathological study on the prognosis of childhood IgA nephropathy and glomerular basement membrane lesions (1989)
    Springer
    Pediatric nephrology 3 (1989), S. 242-247 
    Details
    ISSN: 1432-198X
    Schlagwort(e): IgA nephropathy ; Electron microscopy ; Glomerular basement membrane lesions ; Prognosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Seventy-three patients with IgA nephropathy (IgAGN), under the age of 15 years at the time of the discovery of the disease, were investigated with respect to glomerular basement membrane (GBM) lesions. Irregular attenuation or widening of GBM, especially on the epithelial side, was observed in 28 cases (38%). These two changes are referred to aslysis of GBM and were considered to be the primary and specific changes among the GBM lesions in IgAGN. GBM thickening with layering of lamina densa was found in 37 of 73 cases (51%), but this change has been observed in other types of glomerular diseases. GBM lesions similar to those seen in IgAGN were also observed in Henoch-Schönlein purpura nephritis (HSPN) and poststreptococcal acute glomerulonephritis (PSAGN). Lysis of GBM was observed only in IgAGN, HSPN and PSAGN. Subepithelial and intramembranous deposits appeared to have an important role in the development of these GBM lesions. The presence of GBM lesions was correlated with a high incidence of cellular crescents but not with other clinical or light microscopic findings. The presence of these GBM lesions in IgAGN does not have a significant effect on the prognosis, at least in childhood. The affected GBM seemed to recover without leaving any significant residual damage in most cases. In the long-term prognosis of the disease non-immunological factors, such as ageing or hypertension, seem to be important.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00858523
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  • 33
    Digitale Medien
    Digitale Medien
    Diffusion barrier properties of the perineurium: an in vivo ionic lanthanum tracer study (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 237-242 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Perineurium ; Lanthanum ; Diffusion barriers ; In vivo ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary While the perineurium as a diffusion barrier has been extensively investigated by light and electron microscopy, copy, such studies have been largely restricted to the use of protein tracers. In the present study the permeability of the perineurium to a physiologically more relevant ionic tracer has been assessed. In vivo the rat sural or tibial nerve was either microinjected with lanthanum nitrate solution for endoneurial application or bathed in the lanthanum solution for epineurial application. The findings generally demonstrated an effective barrier to the tracer which failed to penetrate the inner layers of the perineurium. Only at the highest lanthanum concentration and longest time intervals employed did trace quantities occasionally penetrate the barrier and then only in the presence of some cytopathological changes to the outermost perineurial cells. The usefulness of the microinjection method was limited by the slight but unavoidable trauma to the perineurium. The findings are related to those of other studies which have used electron dense tracers, also to studies using physiological including electrophysiological techniques and morphological including freeze-fracture methods.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315882
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  • 34
    Digitale Medien
    Digitale Medien
    Netherton's syndrome: ultrastructure of the active lesion under retinoid therapy (1989)
    Springer
    Archives of dermatological research 281 (1989), S. 165-172 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Netherton's syndrome ; Retinoid therapy ; Etretin ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A young female patient, expressing the symptom triad of Netherton's syndrome, i.e., ichthyosis linearis circumflexa Comèl, trichorrhexis invaginata and other hair shaft defects, and atopic diathesis, has been treated successfully with the new retinoid preparation Etretin. Our electron microscopical study especially focused on the ultrastructural effect on the characteristic, active part of the skin lesions, which is only found within a narrow borderline just preceding the lesion's margin. In untreated skin, this part is characterized by dermal inflammation, immigrating inflammatory cells, and specific keratinization disturbances: synthesis of keratinization proteins is suppressed, serum exudates invade the epidermis, either filling the intercellular spaces of the upper spinous and the granular layer as finely granular, amorphous material, or they are partly phagocytosed and lie within intracellular, round-oval inclusions. The portions of the lesions lying towards the center are unspecific and represent recovery stages, ultrastructurally resembling stages of normal wound repair. Oral therapy with Etretin did not heal the basic defect, but drastically reduced exoserosis and the deposition of intra- and extracellular material. Keratinization seemed to normalize. The condition of the hair was also improved.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00456387
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  • 35
    Digitale Medien
    Digitale Medien
    Senile plaque-like structures: observation of a probably unknown type of senile plaque by periodic-acid methenamine silver (PAM) electron microscopy (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 137-142 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Senile plaque-like structure ; Periodicacid methenamine silver (PAM) method ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Numerous diffuse senile plaque-like structures (SPLSs) were found in the cerebral cortex from cases with dementia of the Alzheimer type by means of the methenamine-Bodian method. SPLSs varied in shape and size. They were never recognized in the original Bodian, PAS and Congo red preparations, but were positive with anti-β-protein immunostaining and periodic-acid methenamine silver (PAM) methods, which are thought to specifically stain amyloid substance. With PAM electron microscopy, we found sparse aggregations of amorphous, often ramified, structures with fine granular silver deposits in SPLS. Routine electron microscopic examination on the same portion where SPLS were confirmed by PAM electron microscopy revealed amorphous, partially fibrous structures. These structures might be amyloid or amyloid-precursor substance. In SPLSs only a few degenerated neurites and astrocytic processes with glycogen granules were seen. We consider SPLSs to be a kind of senile plaque.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688201
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  • 36
    Digitale Medien
    Digitale Medien
    Hypomyelination in the neonatal rat central and peripheral nervous systems following tellurium intoxication (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 301-309 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Schwann cell ; Oligodendrocyte ; Electron microscopy ; Myelin ; Optic nerve
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Neonatal rats were exposed to Tellurium (Te), via the mother's milk, from the day of birth until sacrifice at 7, 14, 21, and 28 days of age. Light and electron microscopy revealed Schwann cell and myelin degeneration in the sciatic nerves at each age studied. These changes were similar to those described in weanling rats as a result of Te intoxication. In the CNS, hypomyelination of the optic nerves was convincingly demonstrated at 14, 21, and 28 days of age, accompanied by some evidence of myelin degeneration. These changes were also seen in the ventral columns of the cervical spinal cords, although less markedly, and were confirmed by quantitative methods. There was little evidence of oligodendrocyte pathology in the CNS, and it appears that degeneration of these cells is not the primary cause of the CNS hypomyelination, in contrast to the PNS where Schwann cell degeneration has been shown to precede the myelin pathology.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00687760
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  • 37
    Digitale Medien
    Digitale Medien
    The astroblastoma and its possible cytogenic relationship to the tanycyte (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 472-483 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Astroblastoma ; Electron microscopy ; Immunohistochemistry ; Organ culture ; Tanycytes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Two examples of cerebral astroblastoma have been studied by electron microscopy and immunohistochemistry, one of them having been maintained in vitro in an organ-culture matrix system for 8 months and the explants studied by light and electron microscopy at different time intervals. The fine structural characteristics were those of a glial cell type with features intermediary between those of astrocytes and ependymocytes. They recapitulated the structure of the tanycyte, a glial precursor cell which is normally found scattered along the ependymal lining of the embryonal and neonatal mammalian brain, but is distinct from epithelial ependymocytes. The possible origin of some astroblastomas from such a cell would account for a number of characteristics in this enigmatic type of glioma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00687708
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  • 38
    Digitale Medien
    Digitale Medien
    Myelin breakdown in the posterior funiculus of the kitten after dorsal rhizotomy (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 273-280 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Wallerian degeneration ; Myelin breakdown ; Light microscopy ; Electron microscopy ; Marchi staining
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Morphological aspects of myelin breakdown in the posterior funiculus during Wallerian degeneration were studied in kittens subjected to lumbosacral dorsal rhizotomies 6–8 days after birth. The first sign of myelin breakdown was characterized by swollen or shrunken nerve fibers. Shortly thereafter there was an increased occurrence of collapsed myelin sheaths and later of rounded myelin bodies. Myelin was clearly seen in microglial cells. Correlative observations on Marchi-stained material indicated the simultaneous and frequent appearance of Marchi-positive bodies (MPB:s) and myelin bodies. Due to the rapidity of the degeneration process in the kitten, the increase in the occurrence of Marchi-positive granules (MPG:s) seemed to start concomitantly with increased occurrence of MPB:s. However, the frequent occurrence of MPG:s outlasted that for MPB:s. The findings indicate that the MPB:s may be the counterpart to myelin bodies and the MPG:s to lipid droplets. Microglial cells may be responsible for the primary uptake of degenerating myelin and the subsequent transformation of myelin bodies to lipid droplets. The much faster breakdown of myelin and elimination of lipid material in the degenerating posteror funiculus of the kitten, as compared to the adult, seemed to be due not only to the lower myelin content in the kitten, but also to a higher density of microglia and a greater efficiency in the myelin breakdown process in the degenerating posterior funiculus of the kitten.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315885
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  • 39
    Digitale Medien
    Digitale Medien
    Pick bodies in the locus ceruleus (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 10-17 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Locus ceruleus ; Pick bodies ; Lewy bodies ; Immunocytochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In classical Pick's disease with typical Pick bodies, inclusions resembling those present in the cerebral cortex are frequently found in the locus ceruleus. In three such cases Pick bodies were studied by light and electron microscopy and compared with Lewy bodies, inclusions more commonly found in this location. In contrast to the situation in the cerebral cortex, nerve cells with multiple Pick bodies were often found in the locus ceruleus, but in other respects definite light and electron microscopic differences between Pick bodies and Lewy bodies were present. Pick bodies were slightly basophilic and never had a central core or a peripheral halo. They were intensely argyrophilic. Differences in immunocytochemical reactions were especially marked with antibodies to tau and to paired helical filaments. Pick bodies displayed an intense reaction with these two antibodies, contrasting with that of Lewy bodies, which either lacked reactivity or reacted in a peripheral band. By electron microscopy the Pick bodies were composed of random filaments with smooth contour, whereas typical Lewy bodies had fuzzy deposits on filaments that radiated from a central core. Pick bodies in the locus ceruleus therefore maintained their immunocytochemical and electron microscopic characteristics and did not take on the character of Lewy bodies. Such differences point to a different pathogenesis and perhaps etiology of these two types of inclusions and attest to the marked difference clinically and pathologically between Pick's and Parkinson's diseases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00308950
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  • 40
    Digitale Medien
    Digitale Medien
    Electron microscopic and Golgi study in a case of hemimegalencephaly (1989)
    Springer
    Acta neuropathologica 77 (1989), S. 664-666 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Hemimegalencephaly ; Golgi study ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Pathological findings in a case of hemimegalencephaly are presented. Hemispherectomy, performed because of intractable seizures, allowed an electron microscopic and Golgi study. Glial abnormalities consisted of hyperplasia of glia cells with giant astrocytes often containing several nuclei and proliferation of numerous Rosenthal fibers. Golgi stain showed many giant neurons with a perikaryon covered by perisomatic processes, and a complex dendritic tree. Glial abnormalities could be correlated with the firmness of the hemisphere and intense hypersignal on magnetic resonance imaging. Giant neurons were associated with an increase in size of the perikaryon and dendritic tree; this pattern suggests a polyploidy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00687896
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  • 41
    Digitale Medien
    Digitale Medien
    Morphological studies on cerebral cortical lesions induced by transient ischemia in Mongolian gerbil —Diffuse and peripheral pallor of the neuronal perikarya (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 1-8 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Cerebral ischemia ; Ischemic neuronal injury ; Long-term recovery ; Mongolian gerbil ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Unilateral transient cerebral ischemia was produced in Mongolian gerbils by clipping the left common carotid artery for 1h. About 60% of the gerbils with neurological symptoms had post-ischemic seizures. The majority of those that had seizures died within a few days, and sections of their cerebral cortices contained many dark and shrunken neurons. However, the gerbils that did not have seizures survived without any severe complications. In the cerebral cortex of the latter, the neurons with diffuse or peripheral pallor of the perikarya were seen along with a small number of dark and shrunken neurons. Diffuse pallor occurred within a few hours following ischemia in layers III, V and VI, and disappeared 1 or 2 days after recirculation. Electron microscopically, these neurons showed dispersion of ribosomes, simple and elongated profiles of rough endoplasmic reticulum (r-ER), clustered vacuoles, and mild to moderate mitochondrial swelling. Occasional net-like tubulomembranous structures, probably derived from r-ER, were observed. On the other hand, peripheral pallor became apparent after 5 days following ischemia, usually involving layer II first and gradually extending to the deeper layers. Concomitantly, the amount of neuropil decreased and the dendrites exhibited tortuosity and irregularity in layer II. Electron microscopically, these neurons showed marked swelling of peripheral perikarya and polyribosomes and organelles were located peripherally to the nuclei. In addition, numerous degenerated axon terminals and distended dendrites were observed around the neurons. These observations indicate that diffuse pallor represents damage directly induced by ischemia and subsequent recirculation, while peripheral pallor is the delayed and remote effect of ischemia, probably due to degeneration of neuronal processes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00687395
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  • 42
    Digitale Medien
    Digitale Medien
    Sporadic motor neuron disease with Lewy body-like hyaline inclusions (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 555-560 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Sporadic motor neuron disease ; Lewy body-like hyaline inclusions ; Immunocytochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Lewy body-like hyaline inclusions were immunocytochemically and electron microscopically investigated in a patient with sporadic motor neuron disease. The hyaline inclusions were chiefly observed within the perikarya of both normal-looking and chromatolytic anterior horn cells in the lumbar spinal cord, but some were detected in the axons and dendrites. Usually, a single inclusion was found in the perikaryon, but in rare cases two or more were observed. Immunocytochemically, these inclusions were intensely immunostained with anti-ubiquitin anti-body. Ultrastructurally, the hyaline inclusions were chiefly composed of randomly arranged linear structures associated with ribosome-like granules, varying from compactly arranged linear densities to more loosely packed ones. They contained scattered vesicles of various sizes and occasionally a focal accumulation of randomly arranged 10-nm neurofilaments or 13–25-nm filamentous structures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00687719
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  • 43
    Digitale Medien
    Digitale Medien
    Disseminated human neurocysticercosis (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 594-604 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Neurocysticercosis ; Pathogenesis ; Histochemistry ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary This study was based on two cases of disseminated human neurocysticercosis from India. The material availabel was examined grossly, and by light microscopy, histochemistry, immunomorphology and electron microscopy. The results showed that the parasites commonly embolized to the anatomically discernable gray-white matter junction of the brain and were located in cavities, the walls of which were dilated vascular channels. The parasite-nutrition process was through endocytosis and microtrichal activity. To camouflage themselves from the host-defense mechanisms, the parasites apparently covered themselves with host-tissue-like material. Host reactivity to the parasite was heralded morphologically by the physical anchoring of the parasite by activated endothelial cells, loss of the host-tissue-like cover and an acute polymorphonuclear leucocytic response.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00691286
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  • 44
    Digitale Medien
    Digitale Medien
    Melanotic paraganglioma of the orbit: a case report (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 340-346 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Paraganglioma ; Melanin ; Orbit ; Immunocytochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A paraganglioma of the orbit in a 21-year-old woman is presented, containing oculo-cutaneous melanin in many tumor cells, occasionally adjacent to neurosecretory granules, and in macrophages. This tumor expands the list of neuroectodermal tumors with potential melaninization.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00294673
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  • 45
    Digitale Medien
    Digitale Medien
    Synaptogenesis in the dorsal lateral geniculate nucleus of the rat (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 243-257 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Dorsal lateral geniculate nucleus ; Synapse formation ; Synaptic glomerulus ; Rat ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Synapse formation and maturation were examined in the rat dorsal lateral geniculate nucleus (dLGN) from birth to adulthood. Examination of animals, whose ages were closely spaced in time, showed that the maturation of the synaptic organization of the nucleus takes place chiefly during the first 3 weeks of postnatal life. This period of maturation may be divided into 3 broad stages. During the first stage, which spans the first 4 days of life, there are only a few immature synapses scattered throughout the nucleus; occasionally aggregates of 3 or 4 synapses are encountered. Dendrodendritic synapses first appear at the end of this stage. The second stage, which lasts from the end of the first stage through day 8, is characterized by intensive synaptogenesis as well as extensive growth and degeneration. For the first time, large boutons resembling retinal terminals form multiple synaptic contacts with dendrites and dendritic protrusions; these synaptic arrangements are partially covered by glial processes. A feature characteristic of the developing dLGN during the first 2 postnatal weeks, and particularly during the second stage, is the presence of membrane specializations that resemble vacant postsynaptic densities. These specializations, which may be unapposed or opposite another neuronal process, decrease in frequency as the number of synapses increases. It is not known whether these densities are converted to synapses or whether they result from loss of presynaptic elements. The third stage in the process of synaptogenesis, which spans a period between days 10 and 20, is characterized by myelination and by the diminution of growth cones, degenerating profiles and vacant postsynaptic densities. There is also a very significant increase in the number and maturation of synapses including synaptic glomeruli. However, it is not until the end of this stage that synapses appear qualitatively indistinguishable from synaptic arrangements identified in adult animals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315883
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  • 46
    Digitale Medien
    Digitale Medien
    Biologic roles of the innermost cell layer of the outer root sheath in human anagen hair follicle: further electron microscopic study (1989)
    Springer
    Archives of dermatological research 281 (1989), S. 254-259 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Innermost cell layer ; Tonofilaments ; Huxley's cells ; Henle's cells ; Anagen hair follicles ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary To elucidate the biologic roles and further cytologic characteristics of the innermost cell (IMC) layer of the outer root sheath (ORS), human anagen hair follicles were ultrastructurally examined. In the lower follicle, the transeversely running tonofilaments in the inner side of the cytoplasm of the IMCs showed a massive accumulation, facing the keratinized part of a Huxley's cell protruding through a Henle's pore. In a rare instance, a spindle-shaped cell was seen between the IMC layer and the keratinized Henle's layer. At the lower isthmus portion, some of the IMCs containing a large number of tonofilaments showed a partial degeneration of the inner side of the cytoplasm. More distally, intercellular spaces between the keratinized IMCs and keratinized Henle's cells were partly dilated and contained amorphous substances. It is suggested that the IMCs in the lower follicle may play a role to support and cover the inner hair structures, tightly as hoops of a barrel. In the isthmus portion, the IMCs may loosely support and guide the keratinized Henle's cells undergoing degeneration.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00431059
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  • 47
    Digitale Medien
    Digitale Medien
    Retinal axons innervate the embryonic chick diencephalon in an in-vivo-like pattern in expiant co-cultures (1989)
    Springer
    Experimental brain research 75 (1989), S. 563-568 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Retina ; Diencephalon ; Co-culture ; Synapses ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Explants of chick embryo diencephalon co-cultured with explants of retina display areas of complex neuropil containing large retinal-like endings which establish synaptic contact with conventional and presynaptic dendrites. Transection of fibre bundles linking retinal to diencephalic explants results in the degeneration of endings of this type, suggesting that axons of extrinsic (retinal) origin innervate the diencephalic explants in an in-vivo-like manner.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00249907
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  • 48
    Digitale Medien
    Digitale Medien
    A quantitative analysis of the synaptic development of the lobus parolfactorius of the chick (Gallus domesticus) (1989)
    Springer
    Experimental brain research 78 (1989), S. 425-434 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Avian forebrain ; Synapses ; Stereology ; Disector ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The lobus parolfactorius (LPO) of the chick has been shown to undergo an increase in the mean synaptic numerical density (Nv syn) in response to one-trial passive avoidance learning (Stewart et al. 1987). The present study was undertaken in order to describe the pattern of normal development of synapses in the LPO, to further investigate the significance of this plastic response. The LPO's from each hemisphere of pre-hatch (16 days), and post-hatch (1 day, 9 day and 22 day old) chicks were processed for electron microscopy. Synapses were classified into asymmetric spine, asymmetric shaft, symmetric spine, and symmetric shaft synapses, on the basis of the density of the post-synaptic thickening and the nature of the post-synaptic target. A 3-dimensional stereological probe was used (the ‘disector’) to calculate Nv syp, and mean projected height (H syp) of the post-synaptic density (PSD). Mean values for each age and hemisphere were compared with a 2-way analysis of variance test using paired samples. A six-fold increase in Nv syp was seen between 16 days in ovo, and 9 days post-hatch. There was a hemispheric asymmetry at 9 days post-hatch, with the left hemisphere LPO containing 1.6 times as many synapses per μm-3. There was a subsequent period of reduction in synaptic density in the left hemisphere LPO between 9 and 22 days post-hatch. The Nv of all classes of synapse increased with age, but the proportions of the symmetrical synapses with respect to the total number of synapses, decreased with age. This decrease was of a similar magnitude for each hemisphere. A hemispheric difference was seen in post-hatch asymmetric synapses, with a greater proportion of asymmetric spine synapses in the left hemisphere. The magnitude of the hemispheric asymmetry was constant throughout the 3 week period of post-hatch development, but was not present in pre-hatch chicks. The PSD increased in length in each hemisphere by approximately 40% between post-hatch day 1 and post-hatch day 9. These data show that the LPO contains a synaptic population which undergoes substantial modification during the first week post-hatch. An asymmetry exists at post-hatch day 9 which is not present at the earlier ages investigated, nor indeed after 22 days post-hatch. This may have significance with regard to studies of passive avoidance learning in the one-day old chick, where an increase in both the size and number of synapses in the LPO has been demonstrated (Stewart et al. 1987). It is possible that ‘training’, in this situation, may simply enhance the timing of synaptic events that result as a consequence of normal development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00228916
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  • 49
    Digitale Medien
    Digitale Medien
    Rodent and primate adrenal medullary cells in vitro: phenotypic plasticity in response to coculture with C6 glioma cells or NGF (1989)
    Springer
    Experimental brain research 76 (1989), S. 38-46 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Nerve growth factor ; C6 glioma cells ; Chromaffin cells histofluorescence ; Electron microscopy ; Immunocytochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In order to maintain a chronic supply of growth factor for medulla cells in vitro, chromaffin cells from rat, African green monkeys and man were co-cultured with C6 glioma cells, which secrete growth factors that sustain sympathetic neurons in vitro. The response of chromaffin cells to coculture was compared to treatment of medullary cells with nerve growth factor (NGF) alone. Dispersed chromaffin cell preparations were obtained by a trypsin-collagenase procedure, and subjected to differential plating on collagen-coated surfaces. With both human and monkey tissue, non-chromaffin cells did attach to the culture plates and an enriched chromaffin cell population could be replated. Rat adrenal medulla cells survived very poorly in vitro and were not enriched in this procedure. Cultured human and monkey chromaffin cells survived as epithelial cells (50%) and showed neuritic outgrowth on 55 to 66% of the cells after eight days when treated with nerve growth factor (NGF). These cells showed strong catecholamine histofluorescence, tyrosine hydroxylase (TH) and dopamine beta hydroxylase (DBH) immunoreactivity. In contrast, only ten percent of adult rat chromaffin cells survived in culture, although NGF treatment rescued an additional 20% of the cells and induced neuritic outgrowth after one week in vitro. C6 glioma cells were treated with mitomycin C bromodeoxyuridine to inhibit mitosis and were plated with the various medulla cells in a one to one ratio. Both human and monkey chromaffin cells expressed extensive and enhanced neuritic arborization within eight days of co-culture, (64–82% respectively) and exhibited intimate contact with the glioma cells as seen at the ultrastructural level. Importantly, survival of adult rat adrenal medulla cells was enhanced to 50% or more with 40% of the cells extending neurites when co-cultured with glioma cells for seven days. Chromaffin cells from all three species reacted for TH, DBH and PNMT in co-culture and were histofluorescent. The majority of these cells were also immunoreactive for serotonin and enkephalin, while only 37% of chromaffin cells indicated the presence of NPY. These data indicate that adrenal medulla can be maintained in vitro as the neuronal phenotype when co-cultured with growth factor producing cells and that this strategy may be useful for in vivo transplantation studies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00253621
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  • 50
    Digitale Medien
    Digitale Medien
    Localization of aggregation substances of Enterococcus faecalis after induction by sex pheromones (1989)
    Springer
    Archives of microbiology 151 (1989), S. 491-497 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Aggregation substance ; Enterococcus faecalis ; Electron microscopy ; Field emission scanning electron microscopy ; Immunogold labelling technique ; Sex pheromone system
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The distribution of sex pheromone induced aggregation substance was studied on the cell surface of various Enterococcus faecalis strains. In the accompanying paper we have shown that the aggregation substance appears as a layer of hairlike structures. Using direct and indirect immunogold technique, transmission electron microscopy and high resolution scanning electron microscopy we investigated the appearance and distribution of the aggregation substance. The “hairs” increase in number with increasing exposure to sex pheromones (maximum density: 1300/μm2). We show that these structures are unequally distributed over the cell surface, even if the cells were induced by sex pheromones for a long period of time. Statistical analysis of the unequal distribution indicates that aggregation substance is incorporated into pre-existing “old” cell-walls and that this incorporation shows a saturation ca. 40 min after addition of sex pheromones.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00454864
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  • 51
    Digitale Medien
    Digitale Medien
    Human fetal endometrium -light and electron microscopic study (1989)
    Springer
    Archives of gynecology and obstetrics 246 (1989), S. 169-179 
    Details
    ISSN: 1432-0711
    Schlagwort(e): Human fetal endometrium ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Human fetal endometrium was examined by light and electron microscopy. Our study shows the following new morphological aspects: (1) Glands are already present. (2) Endometrium undergoes a maturation process during gestation and at late gestational age resembles late proliferative endometrium. (3) The nuclear bodies are present in cell nuclei throughout gestation. (4) Nucleolar channel systems (NCS) sometimes appear at a late gestational age. (5) Cells with the same morphology as that of endocrine cells are found in the basal layers of endometrium at a late gestational age. The significance of these morphological aspects is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00934078
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  • 52
    Digitale Medien
    Digitale Medien
    Synovial lining cells (1989)
    Springer
    Rheumatology international 9 (1989), S. 49-51 
    Details
    ISSN: 1437-160X
    Schlagwort(e): Synovium ; Monoclonal antibodies ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The cells making up the lining of the synovium have long been known as type A and B synoviocytes, with an intermediate form sometimes also described. Accumulating evidence shows that the type A cells are macrophages and the type B cells are fibroblasts. Recently, a definite orientation of these cells within the synovial lining has been observed. The number of synovial lining cells increases in joint disease, and this now seems more likely to be due to cellular recruitment rather than local proliferation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00270244
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  • 53
    Digitale Medien
    Digitale Medien
    Mitochondrial encephalomyopathy with pilovacuolar inclusion or phenocopy with mitochondrial artefact? (1989)
    Springer
    Journal of neurology 236 (1989), S. 361-363 
    Details
    ISSN: 1432-1459
    Schlagwort(e): Mitochondrial encephalomyopathy ; MELAS ; Mitochondrial inclusion ; Pilovacuolar inclusion ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The case of a 33-year-old man with clinical features of mitochondrial encephalomyopathy is presented. He suffered from recurrent cerebral infarctions, cerebellar ataxia, deafness, retinopathy, weakness, and cardiac and renal disorders. Biochemical and light microscope investigations of skeletal muscle did not show any mitochondrial abnormality. Electron microscopy revealed the presence of a hitherto unreported peculiar “pilovacuolar” inclusion in numerous mitochondria, composed of an electron dense pile or rod within a vacuole, while globular or crystalline inclusions were absent.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00314383
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  • 54
    Digitale Medien
    Digitale Medien
    An experimental study of mucociliary pathology of the eustachian tube in otitis media with effusion induced by irradiation (1989)
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 428-432 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Otitis media with effusion ; Mucociliary system ; Eustachian tube ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We have examined the function and fine structure of the mucociliary system of the eustachian tube in an experimental study of otitis media with effusion induced by X-ray irradiation. Functional examination demonstrated that the ciliary activity was diminished in such a condition, while morphological observations showed pathological findings including compound cilia, vacuolation of ciliated cells and expansion of intercellular space. These findings show that irradiation-induced otitis media with effusion results in impairment of the mucociliary system. As evidenced by these studies, the mucociliary system in the eustachian tube has an important role in the clearance of fluid produced in the tympanic cavity as well as affording improvement in this disease.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00464303
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  • 55
    Digitale Medien
    Digitale Medien
    Electron-microscopic study on the anterior pituitary gland of spontaneous dwarf rats (1989)
    Springer
    Cell & tissue research 258 (1989), S. 477-482 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Anterior pituitary gland ; Electron microscopy ; Growth hormone ; Spontaneous dwarf rats (dr/dr)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The spontaneous dwarf rat is a novel experimental model animal on the study of pituitary dwarfism. The fine structure of the anterior pituitary cells was studied in the immature and mature dwarf rats. Pituitary glands were removed from 5-, 10-, 20-day-old immature dwarfs, adult (45 days-16 weeks) dwarfs and normal 3-month-old rats and processed for electron-microscopic observation. In the control animals, growth hormone cells were readily identified by their ultrastructural characteristics, such as the presence of numerous electron-dense secretory granules, 300–350 nm in diameter, well developed rough endoplasmic reticulum and a prominent Golgi complex. In contrast, growth hormone cells were not found in the anterior pituitary gland of the spontaneous dwarf rat at any age examined. Other pituitary cell types, i.e., luteinizing hormone/ follicle stimulating hormone, thyroid stimulating hormone, adrenocorticotropic hormone and prolactin cells, appeared similar in their fine structure to those found in the control rats. In the pituitary gland of dwarf rats, a number of polygonal cells were observed either with no or relatively few secretory granules. The rough endoplasmic reticulum was arranged in parallel cisternae and the Golgi complex was generally prominent in these cells. In addition, many were found to have abundant lysosomes. A few minute secretory granules were occasionally observed; however, the immunogold technique failed to localize growth hormone or prolactin in the granules. The nature of these cells remained obscure in this study. Since their incidence and fine structural features, other than the secretory granules, were quite similar to those of the growth hormone cells in normal rats, we postulate that these cells are dysfunctional growth hormone cells. These results suggest that the cause of the growth impairment in the spontaneous dwarf rat is due to a defect in the functional growth hormone cells in the pituitary gland, and since other pituitary cell types appeared normal, the disorder seems to be analogous to the isolated growth hormone deficiency in the human.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218859
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  • 56
    Digitale Medien
    Digitale Medien
    Nucleus of the boar spermatozoon: Structure and modifications in frozen, frozen-thawed, or sodium dodecyl sulfate-treated cells (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 1 (1989), S. 264-277 
    Details
    ISSN: 1040-452X
    Schlagwort(e): Nucleoproteins ; Element concentrations ; Electron microscopy ; Image analysis ; X-ray spectrophotometry ; Flow cytofluorometry ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: After cryosubstitution and Epon embedding, or after Nanoplast embedding and very thin sectioning, the chromatin of ejaculated or diluted boar spermatozoa appears to be formed of DNA fibers embedded in a quite homogeneous matrix. After sodium dodecyl sulfate (SDS) treatment, and to a lesser extent after freeze-thawing, the DNA fibers are present mostly between cords, probably proteinaceous in nature. The quantity of free sulfhydryl (SH) groups, as calculated from staining by DACM and flow fluorometry, is increased in thawed or SDS-treated cells. The quantity of NH2 groups, calculated from electron microscopy image analysis of alcoholic phosphotungstic acid-stained cells, is decreased in thawed nuclei. The DNA is more accessible to the fluorochrome ethidium bromide after freeze-thawing, and its sensitivity to HCI hydrolysis is modified, during the Feulgen-like staining procedure using acriflavine. The X-ray energy dispersive analysis of cryosections of nuclei indicates that the slight separation of DNA and nucleoproteins in freeze-thawed spermatozoa could result from a dramatic modification of the nuclear ionic environment during thawing.
    Zusätzliches Material: 17 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mrd.1080010407
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  • 57
    Digitale Medien
    Digitale Medien
    Light- and electron-microscopic investigation of the rat subcommissural organ grafted under the kidney capsule, with particular reference to immunocytochemistry and lectin histochemistry (1989)
    Springer
    Cell & tissue research 258 (1989), S. 499-514 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Subcommissural organ ; Secretory activity, neural control ; Transplantation ; Long-spacing collagen ; Immunocytochemistry ; Molecular markers (neuronal, glial) ; Electron microscopy ; Rat (Sprague-Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary There is increasing evidence that, in the rat, a serotonin-mediated neural input may have an inhibitory influence on the secretory activity of the subcommissural organ (SCO). In the present investigation the rat SCO was studied 7, 30 and 90 days after transplantation under the kidney capsule, an area devoid of local serotonin-containing nerves. The grafted tissue was examined by use of immunocytochemistry employing a series of primary antisera, lectin histochemistry and transmission electron microscopy. The grafted SCO survived transplantation and contained, in addition to secretory ependymal and hypendymal SCO-cells, also elements immunoreactive with antisera against glial fibrillary acidic protein or S-100 protein. In transplants, SCO-cells produced a material displaying the characteristic immunocytochemical and lectin-binding properties of SCO-cells observed under in-situ conditions. The ependymal cells lined 1–3 small cavities, which contained secretory material. A fully developed structural equivalent of Reissner's fiber was, however, never found. The immunocytochemical and ultrastructural study of the grafted SCO showed an absence of nerve fibers within the graft and suggested a state of enhanced secretory activity. A network of protruding basal lamina structures connected the secretory cells to the newly formed capillaries revascularizing the SCO. One week after transplantation, long-spacing collagen started to appear in expanded areas of such laminar networks and also in the perivascular space. It is suggested (i) that the formation of long-spacing forms of collagen is triggered by factors provided by the SCO-secretory cells, and (ii) that secretory material of the ependymal and hypendymal cells may reach the reticular extensions of the basal lamina. In contrast to the SCO in situ, the grafted SCO-cells showed a positive immunoreaction for neuron-specific enolase. They became surrounded by a S-100-immunoreactive glial sheath that separated them from other transplanted cell types and the adjacent kidney tissue of the host.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218862
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  • 58
    Digitale Medien
    Digitale Medien
    Localization of cholesterol in the colonic epithelium of the guinea pig: regional differences and functional implications (1989)
    Springer
    Cell & tissue research 258 (1989), S. 339-347 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Proximal colon ; Distal colon ; Cholesterol ; Filipin ; Freeze-fracture ; Electron microscopy ; Guinea Pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary It is generally accepted that variations in membrane cholesterol content affect the fluidity of the bilayer, thus altering its permeability. In the biological membranes, in physiological conditions, a high cholesterol content rigidifies the bilayer decreasing its permeability, a lower cholesterol content induces the opposite effect by increasing the permeability. Since differences in the epithelial permeability for short chain fatty acids have previously been demonstrated in the proximal and distal colon of the guinea pig, these two regions were investigated to establish whether differences in membrane cholesterol content of the absorbing cells can be demonstrated. Freeze-fracture replicas of filipin-treated colonic tissue were used. The results show that in the proximal colon the density of filipin cholesterol complexes located on the luminal plasma membrane of the columnar absorbing cells was significantly higher (about twice) than in the distal colon. Therefore the lower amount of cholesterol present in the membrane of the absorbing cells in the distal colon indicates a greater fluidity of the membranes of the epithelial cells in this region. Such fluidity could be correlated to the higher absorption rates of shortchain fatty acids characteristic of this region.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00239454
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  • 59
    Digitale Medien
    Digitale Medien
    Mallomonas alphaphora (Chrysophyceae), a new species from Western Australia (1989)
    Springer
    Plant systematics and evolution 164 (1989), S. 209-214 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Algae ; Chrysophyceae (Synurophyceae) ; Mallomonadaceae ; Mallomonas alphaphora ; Electron microscopy ; phytoplankton ; scale-bearing flagellate ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new species ofMallomonas, M. alphaphora (Chrysophyceae), was found in freshwater ponds in the Perth region, Western Australia. It is distinguished from other species ofMallomonas by its very distinctive scale and bristle morphology and is placed in a new section,Alphaphorae, of the genusMallomonas.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940438
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  • 60
    Digitale Medien
    Digitale Medien
    Nasal lymphoid tissue in the rat (1989)
    Springer
    Cell & tissue research 255 (1989), S. 193-198 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Mucosa-associated lymphoid tissue ; Nose ; Lymphoepithelium ; Electron microscopy ; Immunohisto-chemistry ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The structure and organization of paired lymphoid tissue in the nasal mucosa, situated in the transitional zone on both sides of the septal opening to the pharyngeal duct, of conventionally-housed rats was examined by light microscopy and scanning and transmission electron microscopy. Each lymphoid structure consisted of follicles containing T- and B-cell areas, and was covered with specialized epithelium. This epithelium consisted of cuboidal ciliated cells with oval nuclei parallel to the basal lamina. Goblet cells were sparse. Occasionally, islands of microvilli-bearing cells (so called membraneous or M cells) covered the lymphoid structures. M Cells were also found as single cells among the ciliated cells. The morphological characteristics and the particular localization justify the conclusion that the nasal lymphoid tissue described belongs to the mucosa-associated lymphoid tissue. It is therefore suggested that this nasal structure be designated nasal lymphoid tissue.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00229081
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  • 61
    Digitale Medien
    Digitale Medien
    Immunocytochemical and ultrastructural studies on allografts of the pituitary neurointermediate lobe in the third cerebral ventricle of the rat (1989)
    Springer
    Cell & tissue research 255 (1989), S. 393-404 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pituitary gland ; Neural lobe ; Intermediate lobe ; Intraventricular graft ; Immunocytochemistry ; Electron microscopy ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Neurointermediate lobes from adult or 10-dayold rats were implanted by a stereotaxic procedure into the third ventricle of adult male rats, in an area close to the paraventricular nucleus. They were examined, using immunocytochemical and ultrastructural techniques, at times ranging from 1 week to 8 months. All grafts were recovered in a healthy condition although some rejection of the tissue was detected at the 1and 2-week stages. In the neural lobe, clusters of pituicytes were scattered among the loose network of capillaries, most of which had a fenestrated endothelium. The intermediate lobe remained organized in compact avascular lobules. Axons similar to those projecting into the neurointermediate lobe in situ, but also axons of other types (e.g., somatostatinergic, enkephalinergic) penetrated the grafts. Synapses with melanotrophic cells in the intermediate lobe and neurohaemal contacts in the neural lobe were frequent from 2 1/2 months after transplantation. Immunocytochemical and ultrastructural characteristics indicated intense secretory stimulation of the melanotrophic cells in the early stages. All cells enclosed in a same glandular lobule reacted in a similar manner. In later stages, when re-innervation occurred, the cells recovered their initial characteristics. The overall effect of the re-innervation of the intermediate lobe grafted in this location is inhibitory, as in the lobe in situ.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00224123
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  • 62
    Digitale Medien
    Digitale Medien
    Gestational changes in hamster adrenal cortex: Morphometric and ultrastructural stereologic studies (1989)
    Springer
    Cell & tissue research 256 (1989), S. 241-246 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adrenal cortex ; Pregnancy ; Electron microscopy ; Stereology ; Golden hamster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the hamster, the weight of the adrenal glands increases during the course of gestation, with the highest value at day 5. In comparison to non-pregnant control animals, there were no changes in the volume of the zona glomerulosa (ZG) and zona fasciculata (ZF), while the volume of the zona reticularis (ZR) increased notably. The average volume of ZG-cells rose at day 5 of pregnancy and thereafter gradually decreased to that of control hamsters. A marked drop in the volume of ZF-cells was seen at days 5 and 10 of pregnancy, whereas at day 15 the cells were larger than in controls. At day 5 of pregnancy, a conspicuous increase in the cell volume was found in ZR, followed by lower values at day 10 and again higher than in control hamsters at day 15. The total number of parenchymal cells in hamster adrenal cortex increased at day 10 of gestation, then underwent a marked decrease, reaching the control value at the final day of pregnancy; this drop was mainly due to a reduction in the number of ZF-cells. The changes in the cell volume were paralleled by rather proportional changes in the volume of the mitochondrial compartment and in the quantity of smooth endoplasmic reticulum. The volume of the lipid-droplet compartment significantly rose in the course of gestation in both ZF- and ZR-cells. The cortisol output by adrenal homogenates gradually decreased during pregnancy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218881
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  • 63
    Digitale Medien
    Digitale Medien
    Glomerular podocytes in cultured rat kidney slices (1989)
    Springer
    Cell & tissue research 256 (1989), S. 419-429 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Kidney ; Glomerulus ; Podocytes ; Tissue culture ; Electron microscopy ; Morphometry ; Rat (Sprague Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of rat glomerular epithelial cells (podocytes) in kidney slices in vitro was examined using qualitative and quantitative electron microscopy. The kidney slices were cultured in Medium 199 with Hanks' salts in a 5% CO2/95% O2 environment for up to 14 days. Few changes in podocyte ultrastructure occurred in the first 12 h of culture, but by 24 h cell bodies were rounded, microvilli were present on all podocyte surfaces, and some foot processes had been replaced by flattened expanses of cytoplasm. These changes were more pronounced by 3 days, when some podocytes had developed pseudopodal extensions and appeared to be migrating from glomeruli onto the slice surface. Podocytes could still be identified after 8, 10 and 14 days of culture, although relatively few glomeruli remained at 14 days. Morphometric methods were used to analyse podocyte shape, volume and surface area during the first 4 days of culture. The most significant change involved loss of foot processes: the number of filtration slits per 100 μm of basement membrane decreased from 211.8 ± 15.0 (mean ± SD) at the commencement of culture, to 55.3 ± 22.6 after 2 days (P 〈 0.001). These data provide baseline information for in vitro studies on the effects of nephrotoxins on podocytes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218900
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  • 64
    Digitale Medien
    Digitale Medien
    Granulated peripolar epithelial cells in the renal corpuscle of marine elasmobranch fish (1989)
    Springer
    Cell & tissue research 257 (1989), S. 61-67 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Kidney ; Peripolar cells ; Renal corpuscle ; Electron microscopy ; Raja erinacea, Mustelus canis, Rhinoptera bonasus, Sphryna lewini, Rhizoprionodon terraenovae, Squalus acanthias (Elasmobranchii)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Granulated epithelial cells at the vascular pole of the renal corpuscle, peripolar cells, have been found in the kidneys of five species of elasmobranchs, the little skate (Raja erinaced), the smooth dogfish shark (Mustelus canis), the Atlantic sharpnose shark (Rhizoprionodon terraenovae), the scalloped hammerhead shark (Sphryna lewini), and the cow-nosed ray (Rhinoptera bonasus). In a sixth elasmobranch, the spiny dogfish shark (Squalus acanthias), the peripolar cells could not be identified among numerous other granulated epithelial cells. The peripolar cells are located at the transition between the parietal epithelium of Bowman's capsule and the visceral epithelium (podocytes) of the glomerulus, thus forming a cuff-like arrangement surrounding the hilar vessels of the renal corpuscle. These cells may have granules and/or vacuoles. Electron microscopy shows that the granules are membrane-bounded, and contain either a homogeneous material or a paracrystalline structure with a repeating period of about 18 nm. The vacuoles are electron lucent or may contain remnants of a granule. These epithelial cells lie close to the granulated cells of the glomerular afferent arteriole. They correspond to the granular peripolar cells of the mammalian, avian and amphibian kidney. The present study is the first reported occurrence of peripolar cells in a marine organism or in either bony or cartilagenous fish.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221634
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  • 65
    Digitale Medien
    Digitale Medien
    Revascularization of isolated autologous bone grafts following microsurgical implantation of arteries and veins (1989)
    Springer
    European journal of plastic surgery 12 (1989), S. 29-34 
    Details
    ISSN: 1435-0130
    Schlagwort(e): Revascularization ; Vessel implantation ; Bone grafts ; Corrosion casts ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The microsurgical implantation of a saphenous vascular axis into free transplanted autologous isolated rib segments in Beagle dogs led to complete revascularization of the bone after two, three and four weeks. Indian ink and Mercox-injected specimens showed a vascular network which penetrated the entire cortical layer. Semi-thin sections revealed osteoblasts and osteoclasts visible in the canals of the revascularized cortical layer, while the control specimen without vessel implantation showed nothing but ground substance. The revascularized bones did not contain any necrotic areas. The newly formed vascular system consisted of arteries, veins and their anastomoses. The veins appeared to produce a greater number of new vessels than the arteries.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00226918
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  • 66
    Digitale Medien
    Digitale Medien
    Quantitative electron microscopy of endocrine cells in oxyntic mucosa of normal human stomach (1989)
    Springer
    Cell & tissue research 255 (1989), S. 41-48 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Stomach ; Endocrine cells ; Electron microscopy ; Morphometry ; Man
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An ultrastructural morphometric study of the endocrine cells of the oxyntic mucosa of the stomach in gastric biopsies collected from five male and five female healthy volunteers aged 19–31 was performed. No sex-related differences were disclosed. Endocrine cells accounted for 1.2±0.4% of the epithelial volume and 0.9±0.4% of the mucosal volume, i.e., including the lamina propria. After classification of the specific endocrine cell types according to the ultrastructural morphology of secretory granules, the volume densities of ECL, P and D cells (30±9%, 24±7%, and 22±4% of the entire endocrine cell mass, respectively) were higher than those of other endocrine cell types. In particular, EC cells contributed less than 10% and X cells represented a very low proportion of the total cells. Non-granulated profiles of cells which in all other respects appeared to be endocrine were also found with a volume density of 8±4%. D cells were distinguished by the high fraction of cytoplasm occupied by secretory granules (31±5%). Subdivision of the whole mucosa into four horizontal segments revealed the endocrine cells to be mostly distributed in the three lower, with virtually no endocrine cells in the superficial segment. The quantitative ultrastructural analysis of the endocrine cell population of the normal human oxyntic mucosa provided by this study may allow a better evaluation of physiological and pharmacological variations of the endocrine cell population.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00229064
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  • 67
    Digitale Medien
    Digitale Medien
    Vasoactive intestinal polypeptide (VIP)- and neuropeptide Y (NPY)-containing nerve fibres in the penile cavernous tissue of green monkeys (Cercopithecus aethiops) (1989)
    Springer
    Cell & tissue research 256 (1989), S. 529-541 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Penile erection ; Electron microscopy ; Immunohisto(cyto)chemistry ; Vasoactive intestinal polypeptide (VIP) ; Neuropeptide Y (NPY) ; Cercopithecus aethiops (Primates)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The cavernous body of green monkeys contains many unmyelinated and few myelinated axons. The unmyelinated axons form terminals in the adventitia of the arteries, between trabecular muscle cells, in the interstitium, and close to endothelium cells of the sinuses. All terminals displayed predominantly “small clear vesicles” and very few “large granular vesicles”; “small granular vesicles” were not seen. However, in rabbit penises, terminals with many large granular vesicles are prominent. Immunohistochemistry (PAP technique) showed a dense network of VIP- and NPY-reactive fibres around the arteries and around trabecular muscles. The density of nerve fibres was particularly high around the subendothelial cushions of the helicine arteries. Double staining for NPY and VIP revealed that both peptides were colocalized. Immunocytochemistry (preembedding PAP technique) showed VIP- and NPY-reactivity in terminals with small clear vesicles; the reaction product was bound to the cytoplasmic face of different membrane types. Although the intracellular localization of the reaction product is probably due to artefactual displacement during preparation, the uniformity of the terminals questions the view that large and small granular vesicles in all species characterize peptidergic and noradrenergic terminals, respectively. The essential findings can be summarized as (1) a high degree of uniformity of nerve terminals, (2) colocalization of VIP and NPY, (3) heavy innervation of the subendothelial cushions of the helicine arteries, and (4) possible innervation of endothelial cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225601
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  • 68
    Digitale Medien
    Digitale Medien
    Immature rat epididymal epithelial cells grown in static primary monolayer culture on permeable supports (1989)
    Springer
    Cell & tissue research 256 (1989), S. 573-580 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Epididymis ; Epithelium ; Monolayer culture ; Histochemistry ; Electron microscopy ; Rat (Sprague-Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary N-acetylglucosaminidase (NAG), acid phosphatase (ACP) and alkaline phosphatase (AKP) were localised histochemically in fixed cells from the 37-day-old rat epididymis grown in static monolayer culture for 2–8 days. ACP and NAG were cytosolic enzymes found in perinuclear positions, whereas staining of AKP was consistent with a membranous position. These enzymes were also examined in frozen tissue sections of the epididymis, from rats of the equivalent age, where NAG had intense activity in both supra- and infra-nuclear cytoplasm and ACP was more active apically. For the first time AKP was localised along basolateral membranes of the epithelium and in the lumen of the mid-caput region. The monolayer in culture was of principal cells only and they maintained their polarity and ultrastructural characteristics, but the height of the cells was reduced compared to that obtained in situ.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225606
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  • 69
    Digitale Medien
    Digitale Medien
    Two types of mammosomatotropes in mouse adenohypophysis (1989)
    Springer
    Cell & tissue research 256 (1989), S. 645-648 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Mammosomatotropes ; Adenohypophysis ; Electron microscopy ; Immunohistochemistry ; Mouse (SMA)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Two types of mammosomatotropes (MS), the small-granule and vesicle-granule MS, were detected in mouse adenohypophysis by electron microscopy and immunohistochemistry. Both cell-types were immunoreactive to prolactin (PRL) and growth hormone (GH) antisera. The small-granule MS contained small, round, solid secretory granules about 100 nm in diameter, and were smaller than the classical GH and PRL cell-types. The vesicle-granule MS contained secretory granules like cored vesicles, and were larger than classical GH and PRL cells. Small-granule MS were immunoreactive to both PRL and GH antisera in the same region of the cell cytoplasm; the vesicle-granule MS, however, were immunoreactive to only PRL antiserum in most cytoplasmic areas, and a positive response to both PRL and GH antisera was confined to only certain small areas.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225615
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  • 70
    Digitale Medien
    Digitale Medien
    Synthesis and X-ray characterization of double oxides of the formula Cr1-xW1+xO4 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 153-157 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Darstellung und röntgenographische Charakterisierung von Doppeloxiden der Formel Cr1-xW1+xO4Mixed-Valenz-Verbindungen der Formel Cr1-xW1+xO4 wurden bei 1300°C dargestellt. Aus Röntgenbeugungsdiagrammen konnten drei verschiedene Phasen identifiziert werden, eine vom Rutiltyp für 0,40 ≤ x ≤ 0,50 und zwei andere mit Rutil-ähnlichen Strukturen bzw. vom CrWO4-Typ für 0 ≤ x ≤ 0,25 und vom WO2-Typ für 0,80 ≤ x ≤ 1.
    Notizen: Mixed valency compounds of formula Cr1-xW1+xO4 have been prepared at 1300°C. Three phases have been identified by X-ray diffraction: one of rutile type for 0.40 ≤ x ≤ 0.50 and two others with rutile-related structures, i. e. of CrWO4-type for 0 ≤ x ≤ 0.25 and of WO2-type for 0.80 ≤ x ≤ 1.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690116
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  • 71
    Digitale Medien
    Digitale Medien
    Dihalogen(pentafluorphenyl)sulfonium(IV)-hexafluoroarsenat C6F5SX2+AsF6- (X = Cl, Br) und Kristallstruktur von Di(pentafluorphenyl)sulfan (C6F5)2S (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 158-168 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Dihalogen(Pentafluorophenyl)sulfonium(IV) Hexafluoroarsenate C6F5SX2+AsF6- (X = Cl, Br) and Crystal Structure of Di(pentafluorophenyl)sulfane (C6F5)2SThe preparation and spectroscopic characterisation of the halogensulfonium salts C6F5SCl2+AsF6- and C6F5SBr2+AsF6- is reported. The new salts are much more stable than their trifluoromethyl derivatives.In addition the crystal structure of (C6F5)2S is reported. Space group P43212, Z = 4, 478 unique observed diffractometer data, Rint. = 0.07, lattice constants: a = 569.0(5) pm, c = 3785.8(22) pm, V = 1225 times; 10-30 m3.
    Notizen: Es wird über die Darstellung und spektroskopische Untersuchung der Sulfoniumsalze C6F5SCl2+AsF6- und C6F5SBr2+AsF6- berichtet. Die neuen Salze sind bedeutend stabiler als ihre Trifluormethyl-Homologen.Ergänzend wird die Kristallstruktur von (C6F5)2S mitgeteilt. Raumgruppe P43212, Z = 4, 478 unabhängige Reflexe, Rint. = 0,07, Gitterkonstanten: a = 569,0(5) pm, c = 3785,8(22) pm, V = 1225×10-30 m3.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690117
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  • 72
    Digitale Medien
    Digitale Medien
    Berichtigung (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 192-192 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690121
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  • 73
    Digitale Medien
    Digitale Medien
    Complex copper(II) fluorides. X. The ternary system BaF2—CuF2—InF3 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 169-176 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Komplexe Kupfer(II)-fluoride. X. Das ternäre System BaF2—CuF2—InF3Das flüssig-fest-Gleichgewichtsdiagramm des InF3—BaF2-Systems wird mittels DTA bestimmt. Die Fluoride BaInF5, das dimorphe Ba3In2F12 und auch eine kubische Phase Ba1-xInxF2+x, deren Struktur sich von der des BaF2 ableitet, wurden gefunden. Die zwei Formen des Ba3In2F12 geben feste Lösungen. Ein isothermer Ausschnitt des ternären Systems BaF2—CuF2—InF3 bei 540°C wird angegeben. Er zeigt die Existenz nur eines quaternären Fluorides: tetragonales BaCuInF7.
    Notizen: The liquid-solid equilibria diagram of the InF3—BaF2 system is established by D.T.A. The fluorides BaInF5, the dimorphic Ba3In2F12, and also a cubic phase Ba1-xInxF2+x, the structure of which derives from that of BaF2, are disclosed. The two forms of Ba3In2F12 give solid solutions. An isothermal section of the ternary system BaF2—CuF2—InF3 at 540°C is given. It shows the existence of only one quaternary fluoride: tetragonal BaCuInF7.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690118
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  • 74
    Digitale Medien
    Digitale Medien
    Zum chemischen Transport von Chrom- und Manganmonophosphid mit Iod - Experimente und Modellrechnungen (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 192-192 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690122
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  • 75
    Digitale Medien
    Digitale Medien
    Beiträge zur Chemie N-organylsubstituierter Metallamide. XIX. Umsetzung von [Co(NPh2)2]2 mit CO - ein neuer Weg zur Synthese eines Innerkomplexes des Cobalt(II) mit einem Anthranilsäurederivat; Molekularstruktur von [Co(NPh(o—C6CONPh2))2] (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 183-191 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Contributions to the Chemistry of N-substituted Metal Amides. XIX. Reaction of [Co(NPh2)2]2 with CO - a New Way for the Synthesis of an Chelate Complex of Cobalt (II) with an Derivative of Anthranilic Acid; Molecular Structure of [Co(NPh(o—C6H4CONPh2))2]Reaction of CO (1 atm, room temperature) with [Co(NPh2)2]2 (I) in benzene (mole ratio 3 : 1) gives Co(CO)3(NPh2)4(benzene)1·6 (II). By adding more CO to the reaction mixture (mole ratio 6 : 1) Co4(CO)12 (III) and a dark red compound of the analytical composition C50H38CoN4O2 (IV) could be isolated. The structure of the red compound was determined by X-ray diffraction. This investigation show IV to be a cobalt(II) complex of an derivative of the anthranilic acid, [Co(NPh(o—C6H4CONPh2))2] (IV). The cobalt coordination in this compound is a distorted tetrahedron. Crystal data of IV: space group P1 with a = 12.449(1) Å, b = 12.431(1) Å, c = 13.223(1) Å, α = 95.47(1)°, β = 95.37(1)°, γ = 94.10(1)°, and Z = 2.
    Notizen: Bei der Umsetzung von CO (1 atm, Raumtemperatur) mit [Co(NPh2)2]2 (I) in Benzen im Molverhältnis 3 : 1 entsteht Co2(CO)3(NPh2)4(benzen)1,6 (II); im Molverhältnis 6 : 1 bildet sich ein Reaktionsgemisch, aus dem Co4(CO)12 (III) sowie eine dunkelrote Verbindung der analytischen Zusammensetzung C50H38CoN4O2 (IV) isoliert werden kann. Die Röntgenstruktur-bestimmung von IV ergab, daß es sich um den ein Anthranilsäurederivat als Liganden enthaltenden Komplex [Co(NPh(o—C6H4CONPh2))2] IV handelt, der eine verzerrt tetraedrische Koordination aufweist.Kristalldaten für IV: Raumgruppe P1 mit a = 12,449(1) Å, b = 12,431(1) Å, c = 13,223(1) Å, α = 95,47(1)°, β = 95,37(1)°, γ = 94,10(1)° und Z = 2.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690120
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  • 76
    Digitale Medien
    Digitale Medien
    Formation and transformation of δ-Nb2O5 solid solutions in the system Nb2O5—Al2O3 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 177-182 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Bildung und Umwandlung von festen Lösungen des δ-Nb2O5 im Nb2O5—Al2O3-SystemIm System Nb2O5—Al2O3 werden (bis 50 Mol-% Al2O3) mit metastabilem, hexagonalem δ-Nb2O5 feste Lösungen gebildet, bei der Präparation aus den amorphen Substanzen, die durch simultane Hydrolyse von Niob- und Aluminiumalkoxid erhalten werden. Die Werte des Gitterparameters a sind unabhängig von der Zusammensetzung, während der Parameter c linear abnimmt mit steigendem Al2O3-Gehalt. Der übergang δ-Nb2O5 (orthorhombisch) erfolgt bei 640°C bis 700°C. Die 50 Mol-% Al2O3-enthaltende feste Lösung geht bei 800° bis 860°C in monoklines NbAlO4 über.
    Notizen: In the system Nb2O5—Al2O3, solid solutions of metastable δ-Nb2O5 (hexagonal) are formed up to 50 mol% Al2O3 from amorphous materials prepared by the simultaneous hydrolysis of niobium and aluminium alkoxides. The values of the lattice parameter a are relatively constant regardless of composition, while parameter c decreases linearly with increasing Al2O3 content. The δ- to γ-Nb2O5 (orthorhombic) transformation occurs at ≍ 640°C to ≍ 700°C. The solid solution containing 50 mol% Al2O3 transforms to monoclinic NbAlO4 at 800° to 860°C.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690119
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  • 77
    Digitale Medien
    Digitale Medien
    Masthead (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 570 (1989) 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895700101
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  • 78
    Digitale Medien
    Digitale Medien
    Die Reaktion des tert.Butyl-lithiums mit Aluminiumtribromid; Molekülstrukturen von [HAl(CMe3)2]3 und [LiHAl(CMe3)3]2 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 570 (1989), S. 37-53 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Reaction of tert.Butyl-lithium with Aluminiumtribromide; Molecular Structures of [HAl(CMe3)2]3 and [LiHAl(CMe3)3]2The reaction of tert.butyl-lithium with aluminiumtrihalide at low temperatures was reinvestigated. Four compounds were isolated: trimeric di(tert.butyl)alane(III) 1, monomeric (solution in benzene)/dimeric (solid state) lithium-tri(tert.butyl)alanate(III) 2, tri(tert.butyl)alane 3 and lithium-tetra(tert.butyl)alanate 4. X-ray structure analyses gave a planar sixmembered Al—H heterocycle for 1 and a Li—H-bridged dimer showing intramolecular interactions of lithium with C—H σ-bonds for 2.
    Notizen: Die Reaktion des tert.Butyl-lithiums mit Aluminiumtrihalogenid bei tiefen Temperaturen wurde neu untersucht. Dabei isolierten wir: das trimere Di(tert.butyl)alan(III) 1, das monomere (benzolische Lösung)/dimere (Festkörper) Lithium-tri(tert.butyl)alanat(III) 2 sowie Tri(tert.butyl)alan 3 und Lithium-tetra(tert.butyl)alanat 4. Die Röntgenstrukturanalyse ergab einen planaren sechsgliedrigen Heterozyklus aus Al—H-Einheiten für 1 und ein über Li—H-Brücken verknüpftes Dimeres mit intramolekularen Wechselwirkungen zwischen den Lithiumatomen und C—H-σ-Bindungen für 2.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895700103
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  • 79
    Digitale Medien
    Digitale Medien
    Zur Kenntnis von Ammonium-pentanitratopraseodymat und -neodymat (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 106-110 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: On Ammonium Pentanitrato Praseodymate and Neodymate(NH4)2[Pr(NO3)5] · 4 H2O (I) and (NH4)2[Nd(NO3)5] · 4 H2O (II) were obtained from Pr6O11 and Nd2O3 by reaction with nitric acid and NH4NO3. The fixed water molecules could be removed completely with formation of [NH4]2[Pr(NO3)5] (III) and [NH4]2[Nd(NO3)5] (IV). The i.r. spectra indicate only symmetrically bonded bidentate NO3- ligands. The water molecules are bonded as well by hydrogen bridges to NH4+ ions as by EDA interaction to the lanthanoid atoms. Therefore, the constitution of the complexes is described more exactly by the formula [NH4]2[Ln(NO3)5(H2O)2] · 2 H2O.
    Notizen: (NH4)2[Pr(NO3)5] · 4 H2O (I) und (NH4)2[Nd(NO3)5] · 4 H2O (II) lassen sich durch Umsetzung von Pr6O11 bzw. Nd2O3 mit Salpetersäure und Ammoniumnitrat erhalten. Beide Komplexe ließen sich vollständig dehydratisieren unter Bildung von [NH4]2[Pr(NO3)5] (III) bzw. [NH4]2[Nd(NO3)5] (IV). Die Auswertung der IR-Spektren zeigt, daß in den Komplexen ausschließlich zweizähnig gebundene Nitratliganden vorliegen. I und II enthalten unterschiedlich gebundene Wassermoleküle, die teils über Wasserstoffbrücken an die NH4-Ionen, teils koordinativ an die Lanthanoidatome gebunden sind. Die Konstitution dieser Komplexe wird deshalb exakter durch die Formel [NH4]2[Ln(NO3)5(H2O)2] · 2 H2O beschrieben.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690110
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  • 80
    Digitale Medien
    Digitale Medien
    Über die Reaktionen von N-Chloracetonimin mit Molybdänpentachlorid und Wolframhexachlorid Die Kristallstruktur von Me2C=NH2[MoOCl4] (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 83-90 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Reactions of N-Chloroacetoneimine with Molybdenum Pentachloride and Tungsten Hexachloride. Crystal Structure of Me2C=NH2[MoOCl4]WCl6 reacts with N-chloroacetoneimine under elimination of chlorine and formation of pentachloro-isopropylideneimino-tungsten(VI), Cl5W=N=CMe2, a brown-black crystal powder, which was characterized by i.r. spectroscopy. MoCl5 reacts in a similar way, although only a product mixture can be obtained. Partial hydrolysis of this mixture yields isopropylideneiminium-tetrachlorooxomolybdate(V), Me2C=NH2+[MoOCl4]-, of which the crystal structure was determined (2323 unique observed reflexions, R = 0.049). Space group P21/c, Z = 4, a = 878.6, b = 907.2, c = 1252.2 pm, β = 91.29°. The compound consists of Me2C=NH2+ ions with a planar arrangement of the skeletal atoms and a CN bond length of 126.7 pm and of dimeric, centrosymmetric anions [MoOCl4]22- having Mo atoms linked via asymmetric chloro bridges (MoCl distances 238.4 and 307.6 pm). The longer Mo—Cl contacts are located in the trans-positions of the terminal oxoligands (MoO distance 164 pm).
    Notizen: WCl6 reagiert mit N-chloracetonimin unter Chlorabspaltung und Bildung von Pentachlor(isopropylidenimido)wolfram(VI), Cl5W=N=CMe2, einem schwarzbraunen Kristallpulver, das durch sein IR-Spektrum charakterisiert wird. ähnlich verläuft die Umsetzung mit MoCl5, wobei allerdings kein einheitliches Produkt isoliert werden kann. Durch partielle Hydrolyse entsteht aus diesen Produkten Isopropylideniminiumtetrachloro-oxomolybdat(V), Me2C=NH2+[MoOCl4], von dem wir eine Kristallstrukturanalyse angefertigt haben (2323 unabhängige beobachtete Reflexe, R = 4,9%). Raumgruppe P21/c, Z = 4, Gitterabmessungen: a = 878,6; b = 907,2; c = 1252,2 pm; β = 91,29°. Die Verbindung besteht aus Kationen Me2C=NH2+, deren Gerüstatome in einer Ebene liegen und die eine CN-Bindungslänge von 126,7 pm haben, sowie zentrosymmetrischen dimeren Anionen [MoOCl4]22-, deren Mo-Atome über asymmetrische Chlorobrücken mit Mo—Cl-Abständen von 238,4 pm und 307,6 pm verknüpft sind. Die langen Mo—Cl-Kontakte befinden sich in trans-Stellung zu den terminal gebundenen Oxoliganden (Abstand MoO = 164 pm).
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690107
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  • 81
    Digitale Medien
    Digitale Medien
    Bindungsverhältnisse in kristallinen Phasen von Caesiumhydrogensulfid, CsHS und CsDS (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 117-130 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Chemical Bonding in Crystalline Phases of Cesium Hydrogensulfides, CsHS and CsDSReaction of liquid hydrogensulfide, H2S and D2S respectively, with cesium at room temperature in pressure resistant glass tubes quickly gives the crystalline hydrosulfides, CsHS and CsDS. The compounds are characterized by thermochemical, X-ray, and neutron diffraction data.Three solid phases of CsDS are observed as a function of temperature: Changes in chemical bonding are discussed with respect to temperature and in comparison with alkali metal hydroxides, amides, halides, and further hydrogensulfides.
    Notizen: Flüssiger Schwefelwasserstoff, H2S bzw. D2S, reagiert bei Raumtemperatur in druckfesten Glasgefäßen schnell mit Caesium, wobei kristallines Caesiumhydrogensulfid, CsHS bzw. CsDS entsteht. Thermochemische, Röntgen- und Neutronenbeugungsdaten charakterisieren die Verbindungen. Drei feste Phasen von CsDS wurden in Abhängigkeit von der Temperatur beobachtet: Änderungen der chemischen Bindung werden in Abhängigkeit von der Temperatur und durch Vergleich mit Alkalimetallhydroxiden, -amiden und -halogeniden sowie weiteren -hydrogensulfiden diskutiert.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690112
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  • 82
    Digitale Medien
    Digitale Medien
    Darstellung und Kristallstruktur von Lithiumhydrogensulfid, LiHS (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 111-116 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Preparation and Crystal Structure of Lithiumhydrogensulfide, LiHSLithiumhydrogensulfide, LiHS, is prepared from lithiumamide, LiNH2, by reaction with liquid hydrogensulfide. At 150°C the solubility of LiHS in H2S is sufficient for the growth of single crystals in a temperature gradient within the autoclaves used. The X-ray structure determination at 295 K is characterized by the following data: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{{{\rm P4}_{\rm 2} } \mathord{\left/ {\vphantom {{{\rm P4}_{\rm 2} } {{\rm mmc,\;Z = 2,\;a = 3.916}\left({\rm 2} \right){\AA},\;c = 6.155\left(2 \right){\AA},}}} \right. \kern-\nulldelimiterspace} {{\rm mmc,\;Z = 2,\;a = 3.916}\left({\rm 2} \right){\AA},\;c = 6.155\left(2 \right){\AA},}}} \hfill \\ {{\rm Z}\left({{\rm F}_{\rm 0}^{\rm 2} \ge 3\sigma \;{\rm F}_{\rm 0}^{\rm 2} } \right) = 74,\;{\rm R = 0.011}{\rm .}} \hfill \\\end{array} $$\end{document} Lithium occupies tetrahedral sites in a distorted cubic close-packed arrangement of S; in PtS sulfur occupies tetrahedral sites in a similar way in a distorted close packing of Pt. Hydrogen atoms of the HS--ions are dynamically disordered in a split position linearly bound to S. At 228 K a thermal effect occurs in DSC-measurements indicating that below this temperature the HS--ion has fixed positions.
    Notizen: Zur Darstellung von Lithiumhydrogensulfid, LiHS, wurde Lithiumamid, LiNH2, in flüssigem Schwefelwasserstoff protolysiert. Bei 150°C reicht die Löslichkeit von LiHS in H2S für die Einkristallzüchtung im Temperaturgefälle von Autoklaven aus. Die röntgenographische Strukturbestimmung bei 295 K ist durch folgende Daten charakterisiert: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{{{\rm P4}_{\rm 2} } \mathord{\left/ {\vphantom {{{\rm P4}_{\rm 2} } {{\rm mmc,\;Z = 2,\;a = 3,916}\left({\rm 2} \right){\AA},\;c = 6,155\left(2 \right){\AA},}}} \right. \kern-\nulldelimiterspace} {{\rm mmc,\;Z = 2,\;a = 3,916}\left({\rm 2} \right){\AA},\;c = 6,155\left(2 \right){\AA},}}} \hfill \\ {{\rm Z}\left({{\rm F}_{\rm 0}^{\rm 2} \ge 3\sigma\; {\rm F}_{\rm 0}^{\rm 2} } \right) = 74,\;{\rm R = 0,011}{\rm .}} \hfill \\\end{array} $$\end{document} In einer verzerrt kubisch flächenzentrierten Anordnung von S besetzt Li Tetraederlücken wie S in der ähnlich verzerrten Kugelpackung von Pt in PtS. Die Hydrogenatome der HS--Ionen sind in zwei linear über S verbundenen Positionen dynamisch fehlgeordnet. DSC-Messungen zeigen bei 228 K einen thermischen Effekt, der die Lagefixierung des HS--Ions vermuten läßt.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690111
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  • 83
    Digitale Medien
    Digitale Medien
    Quantenchemische Modellrechnungen zur Baugruppenwanderung in Hexafluorosilicaten (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 131-136 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Quantum Chemical Model Calculations on the Migration of Si—F Groups in HexafluorosilicatesThe transport of different Si—F species was simulated using two [SiF6]2- octahedra as example. Activation barriers and charge distributions were calculated with the EHT method.Bearing in mind the structure of cubic hexafluorosilicates calculations were carried out on the migration both along an edge and along a (110) face of the elementary cell. At first [SiF2]2+ and SiF4 groups were removed from an [Si2F12]4- unit to produce a surface vacancy. During a second step planar SiF4 groups were moved to the neighbouring lattice position.A diffusion of planar SiF4 is favoured, if the electrostatic interaction between moved and fixed fluorine atoms is as small as possible.
    Notizen: Das EHT-Verfahren wurde genutzt, um am Beispiel von zwei [Sif6]2--Baueinheiten den Transport verschiedener SiF-Spezies zu simulieren und dabei die auftretenden Aktivierungsbarrieren und Ladungsverteilungen zu berechnen. Ausgehend von der Struktur kubischer Alkalihexafluorosilicate wurden Rechnungen zum Transport entlang der Kante und entlang einer (110)-Fläche der Elementarzelle durchgeführt. Dabei wurden zunächst [SiF2]2+- bzw. SiF4-Gruppen aus dem [Si2F12]4--Verband zur Schaffung eines freien Oberflächenplatzes entfernt. In einem zweiten Schritt wurden im Modell [SiF8]4- planare SiF4-Gruppen zum jeweils benachbarten Gitterplatz transportiert.Der Transport eines [SiF2]2+-Moleküls erfordert einen wesentlich höheren Energieaufwand als der Transport von planarem SiF4. Eine Diffusion von planarem SiF4 wird begünstigt, wenn eine möglichst geringe elektrostatische Wechselwirkung zwischen den bewegten und feststehenden Fluoratomen stattfindet.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690113
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  • 84
    Digitale Medien
    Digitale Medien
    Struktur und Eigenschaften quaternärer Chalkogenide MIAIIIBIVX4VI. III. Über die Verbindungen AgTiZrTe4 und Ag2TiZrTe4 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 145-152 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Structure and Properties of Quaternary Chalcogenides MIAIIIBIVX4VI. III. On the Compounds AgTiZrTe4 and Ag2TiZrTe4Preparation and properties of the compounds AgTiZrTe4 and Ag2TiZrTe4 are reported. The structure deduced from X-ray diffraction diagrams is closely related to the structure of TiZrTe4 showing an ordered accomodation of Ti and Zr atoms at the octahedral sites of the CdI2 type structure. The interlayers free of Ti and Zr atoms are suggested to be in part occupied by Ag+ ions in an ordered sequency, which allows to explain the occurrence of 8 Te layers in the repeating unit.
    Notizen: Es wird über die Darstellung der Verbindungen AgTiZrTe4 und Ag2TiZrTe4 und deren Eigenschaften berichtet. Röntgenpulverdiffraktogramme lassen auf enge strukturchemische Beziehungen zum TiZrTe4 mit geordneter Verteilung der Ti- und Zr-Atome auf den Oktaederplätzen des CdI2-Strukturtyps schließen. Für die Ag+-Ionen wird eine partielle Besetzung der Tetraederlücken in den von Ti- bzw. Zr-Atomen freien Zwischenschichten in geordneter Abfolge in Betracht gezogen, die das Auftreten von 8 Te-Schichten in der Wiederholungseinheit erklärt.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690115
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  • 85
    Digitale Medien
    Digitale Medien
    Über Chalkogenolate. 191. Ester der 2-Oxophenyldithioessigsäure 2. Kristall- und Molekülstruktur des Methylesters (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 137-144 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: On Chalcogenolates. 191. Esters of 2-Oxophenyldithioacetic Acid. 2. Crystal and Molecular Structure of the Methyl EsterThe title compound C6H5—CO—CS—SCH3 crystallizes with Z = 2 in the triclinic space group P1 with cell dimensions (-60°C) a = 6.236(4) Å, b = 7.972(2) Å, c = 9.589(4) Å, α = 88.42(3)°, β = 75.39(5)°, γ = 81.54(4)°. The structure has been determined from single crystal X-ray data measured at -60°C and refined to R = 0.085 and Rw = 0.087 for 2307 independent reflections. With nearly 20° the C=O bond is turned out of the plane of the phenyl ring.
    Notizen: Die Titelverbindung C6H5—CO—CS—SCH3 kristallisiert triklin mit Z = 2 in der Raumgruppe P1 mit den Gitterdimensionen (-60°C) a = 6,236(4) Å, b = 7,972(2) Å, c = 9,589(4) Å, α = 88,42(3)°, β = 75,39(5)°, γ = 81,54(4)°. Die Kristallstruktur wurde aus bei -60°C vermessenen röntgenographischen Einkristalldaten unter Verwendung von 2307 symmetrieunabhängigen Reflexen bestimmt und bis auf Zuverlässigkeitsfaktoren von R = 0,085 und Rw = 0,087 verfeinert. Im Molekül ist die C=O-Bindung etwa 20° aus der Ebene des Phenylrings herausgedreht.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895690114
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  • 86
    Digitale Medien
    Digitale Medien
    Crystal structure of cadmium cyclohexaphosphate hexahydrate: Cd3P6O18 · 6 H2O (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 570 (1989), S. 138-144 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Darstellung und Kristallstruktur eines Cadmiumcyclohexaphosphates: Cd3P6O18 · 6 H2OEs werden die Darstellung und die Kristallstruktur von Cd3P6O18 · 6 H2O beschrieben. Die Verbindung besitzt trigonale (rhomboedrische) Symmetrie, die Elementarzellendaten sind: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm a}_{\rm H} = 15.056(10)} & {{\rm c}_{\rm H} = 16.080(10){\rm }{\AA}} \\ \end{array} $$\end{document} oder \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm a}_{\rm R} = 10.212(10){\rm }{\AA}} & {{\rm \alpha }_{\rm R} = 94.98}\deg \\ \end{array} $$\end{document}Die Raumgruppe ist R3 mit Z = 6 in der hexagonalen Aufstellung. Die Kristallstruktur wurde mit Hilfe von 1355 unabhängigen Reflexen bis zu einem R-Wert von 0,013 bestimmt. Die P6O18-Ringanionen weisen eine dreizähnige Symmetrie auf. Das Cadmium-Koordinationspolyeder ist ein leicht verzerrtes Oktaeder, das von vier Sauerstoff-Atomen und zwei Wassermolekülen gebildet wird. Die Wassermoleküle verknüpfen diese Oktaeder zu Sechsringen mit der Symmetrie 3, diese Ringe wechseln sich entlang der 3-Achse mit den P6O18-Ring-Anionen ab.
    Notizen: Chemical preparation and crystal structure of Cd3P6O18 · 6 H2O are described. This compound is trigonal (rhomboedral) with the following unit-cell dimensions: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm a}_{\rm h} = 15.056(10)} & {{\rm c}_{\rm h} = 16.080(10){\rm }{\AA}} \\ \end{array} $$\end{document} or \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm a}_{\rm r} = 10.212(10){\rm }{\AA}} & {{\rm \alpha }_{\rm r} = 94.98}\deg \\ \end{array} $$\end{document}The space group is R3 with Z = 6 for the hexagonal description. The crystal structure has been solved by using 1355 unique reflexions with a final R value 0.013.The P6O18 ring anions have a threefold symmetry. The cadmium coordination polyhedron is a slightly distorted octahedron built up by four oxygen atoms and two water molecules. The water molecules link themselves as to build six-member rings having a 3 symmetry alterning with the P6O18 phosphoric rings along the 3 axes.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895700114
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  • 87
    Digitale Medien
    Digitale Medien
    Transition metal Complexes with the Thiosemicarbazide-based Ligands. VI. Nickel and zinc complexes with S-alkylisothiosemicarbazides (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 570 (1989), S. 167-176 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Übergangsmetall-Komplexe mit Thiosemicarbazid-Liganden. VI. Komplexe von NiII und ZnII mit S-AlkylisothiosemicarbazidDurch Umsetzung der ethanolischen Lösung von Ni(OAc)2 · 4 H2O mit S-Alkylisothiosemicarbazid-Iodwasserstoff (L—R · HI; R = Me, Et, n-Pr, n-Bu) und Pyridin wurden die oktaedrischen Bisligand-Komplexe der allgemeinen Formel [Ni(L—R)2Py2]I2 erhalten. Durch Erhitzen bei 95°C bzw. 110°C wurden die Komplexe in die quadratisch-planaren [Ni(L—R)2]I2 (R = Me, Et) - und [Ni(L—R)2I2] (R = n-Pr, n-Bu) - Komplexe mit verzerrt-oktaedrischer Konfiguration überführt. Ferner wurde in ethanolischer Lösung Zn(L—Me)2I2 dargestellt. Die Verbindungen wurden durch Elementaranalyse, TG, magnetische und spektroskopische Messungen charakterisiert.
    Notizen: The reaction of warm ethanolic solution of Ni(OAc)2 · 4 H2O with S-alkylisothiosemicarbazide-hydrogeniodide (L—R · HI; R = Me, Et, n-Pr, n-Bu) and pyridine yielded the octahedral bis(ligand) complexes of the general formula [Ni(L—R)2Py2]I2. By the isothermal heating at 95 and 110°C, these complexes were transformed into the square-planar [Ni(L—R)2]I2 (R = Me, Et) complexes and the [Ni(L—R)2I2] (R = n-Pr, n-Bu) complexes of distorted octahedral configuration. Besides, the Zn(L—Me)2I2 complex was prepared. The compounds have been characterized by elemental analysis, magnetic measurements, diffuse reflectance spectra and TG analysis.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895700118
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  • 88
    Digitale Medien
    Digitale Medien
    Structure of molten systems KF—K2TiF6 and KCL-K2TiF6 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 570 (1989), S. 184-192 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Struktur der geschmolzenen Systeme KF—K2TiF6 und KCl—K2TiF6Die kongruent schmelzenden Verbindungen K3TiF7 und K3TiF6Cl, die in den Systemen KF—K2TiF6 bzw. KCl—K2TiF6 gebildet werden, zeigen einen starken Einfluß auf die Struktur (ionische Zusammensetzung) der Schmelzen der entsprechenden Systeme. In Anbetracht der relativ niedrigen Symmetrie und des hohen Energiezustandes der TiF73-- und TiF6Cl3--Ionen, sollte für sie ein hoher thermischer Dissoziationsgrad erwartet werden. Diese Annahme wird durch zwei verschiedene Methoden - die thermodynamische Analyse der Phasengleichgewichte und der Volumeneigenschaften bestätigt. Die Werte der Schmelzenthalpie für K2TiF6, K3TiF7 und K3TiF6Cl, die zu den Berechnungen verwendet werden, wurden ebenfalls bestimmt.
    Notizen: Congruently melting compounds K3TiF7 and K3TiF6Cl which are formed in the systems KF—K2TiF6 and KCl—K2TiF6, respectively, exhibit a strong influence on the structure (ionic composition) of the melts of the corresponding systems. Considering the relatively low symmetry and a high energetic state of the TiF73- and TiF6Cl3- complex ions, a high degree of their thermal dissociation might be expected. This assumption was confirmed by two different methods based on a thermodynamic analysis of the phase equilibria and of the volume properties of the investigated systems, respectively. In connection with the former method, the values of the enthalpy of fusion of K2TiF6, K3TiF7, and K3TiF6Cl which were used in the calculations have also been estimated.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895700120
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  • 89
    Digitale Medien
    Digitale Medien
    Experimente zur Mischkristallbildung zwischen Zinktantalaten und -antimonaten: ZnTa2-xSbxO6 und Zn4Ta2-xSbxO9 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 568 (1989), S. 22-28 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Experiments about the Mixed Crystal Formation between Zincoxotantalates and -antimonates: ZnTa2-xSbxO6 and Zn4Ta2-xSbxO9In the area of substituted oxotantalates of zinc two new phases of the composition A: ZnTa1·8Sb0·2O6 and B: Zn4Ta1·2Sb0·8O9 were prepared and investigated by X-ray single crystal technique. A crystallizes with tetragonal symmetry (space group D4h14-P42/mnm, a = 4.7314; c = 9.2160 Å; Z = 2). B is monoclinic (space group C2h6-C2/c; a = 15.103; b = 8.839; c = 10.378 Å; β = 93.81°; Z = 8). A crystallizes with trirutile structure, although there is a small replacement of Ta5+ by Sb5+. B maintains the Zn4Ta2O9 structure. One of the point positions of the M5+ ions is occupied statistically by Ta5+/Sb5+ and Zn2+. B is a metastable compound.
    Notizen: Im Bereich substituierter Oxotantalate des Zinks wurden zwei neue Phasen A: ZnTa1,8Sb0,2O6 und B: Zn4Ta1,2Sb0,8O9 an Einkristallen röntgenographisch untersucht. A kristallisiert tetragonal (Raumgruppe D4h14-P42/mnm, a = 4,7314; c = 9,2160 Å; Z = 2), B monoklin (Raumgruppe C2h6-C2/c, a = 15,103; b = 8,839; c = 10,378 Å; β = 93,81°; Z = 8). A kristallisiert trotz des geringen Ersatzes von Ta5+ gegen Sb5+ im Trirutiltyp. B behält die Struktur von Zn4Ta2O9 bei. Eine Position der oktaedrisch koordinierten M5+-Ionen ist mit Zn2+ statistisch besetzt. B ist metastabil.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895680104
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  • 90
    Digitale Medien
    Digitale Medien
    Ein Oxowolframat mit „Kanalstruktur“: KNa3WO5 (Mit einer Bemerkung über den Aufbau von Na4WO5) (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 143-156 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: An Oxotungstate with „Channel Structure“: KNa3WO5 (With a Remark on Na4WO5)For the first time single crystals of Na4WO5 were prepared by heating of annealing mixtures of Na2WO4 [2] and Na2O [Na:W = 4,2:1, Ni-cylinder, 725°C, 28 d]. Four-circle-diffraktometer data [PW 1100, 1900 IO(hkl), ω-2Θ scan, AgKα-radiation, R = 6,5%, RW = 5,7%] determine the triclinic structure of Na4WO5 with a = 569.4(2), b = 847.7(2), c = 565.7(1) pm, α = 101.29(2)°, β = 102.25(3)°, γ = 109.20(3)°. It is isotypic with the NaCl-type of structure Li4WO5. By heating Na4WO5 with K2O [Na:K:W = 4:3:1, Au-tube, 750°C, 35 d] colourless single crystals of KNa3WO5 were obtained for the first time. The structure determination [four-circle-diffraktometer data, PW 1100, ω-2Θ scan, 943 IO(hkl), MoKα-Strahlung R = 4.9%, RW = 3.9%] proves space group C2/m with a = 907.8(3), b = 753.9(2), c = 911.8(3) pm, β = 104.07(4)°, Z = 4. The structure is characterised by undulating layers of Na, W and O and two different kinds of channels.The Madelung Part of Lattice Energie, MAPLE, Effective Coordination Numbers, ECON, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.
    Notizen: Neu dargestellt wurden farblose Einkristalle von Na4WO5 durch Tempern inniger Gemenge von Na2WO4 [2] und Na2O [Na:W = 4,2:1, Ni-Bömbchen, 725°C, 28 d]. Nach Vierkreisdiffraktometerdaten [PW 1100, 1900 IO(hkl), ω-2Θ-scan, AgKα-Strahlung, R = 6,5%, RW = 5,7%] kristallisiert Na4WO5 triklin mit a = 569,4(2), b = 847,7(2), c = 565,7(1) pm, 101,29(2)°, β = 102,25(3)°, γ = 109,20(3)°, Z = 2. Es ist isotyp mit der Kochsalzvarianten Li4WO5.Durch Erhitzen von Na4WO5 im Gemenge mit K2O [Na:K:W = 4:3:1, Au-Rohr, 750°C, 35 d] wurden erstmals farblose Einkristalle von KNa3WO5 erhalten. Die Strukturaufklärung [Vierkreisdiffraktometerdaten, PW 1100, ω-2Θ-scan, 943 IO(hkl), MoKα-Strahlung R = 4,9%, RW = 3,9%] belegt die Raumgruppe C2/m mit a = 907,8(3), b = 753,9(2), c = 911,8(3) pm, β = 104,07 (4)°, Z = 4. Der Aufbau ist durch gewellte Schichten aus Na, W und O und zwei verschiedene Sorten von Kanälen charakterisiert.Der Madelunganteil der Gitterenergie, MAPLE, Effektive Koordinationszahlen, ECON, diese über Mittlere Fiktive Ionenradien, werden berechnet und diskutiert.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895730115
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  • 91
    Digitale Medien
    Digitale Medien
    Darstellung von CF3SClF+MF6- (M = As, Sb) und Kristallstruktur von CF3SCl2+SbF6- (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 185-194 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Preparation of CF3SClF+MF6- (M = As, Sb) and Crystal Structure of CF3SCl2+SbF6-CF3SClF+MF6- (M = As, Sb) is prepared by oxidative fluorination of CF3SCl with XeF+MF6-. The new salt is characterized by IR, Raman and NMR spectra in comparison with CF3SF2+MF6- and CF3SCl2+MF6-. In SO2 solution CF3SClF+SbF6- symmetrizises into CF3SF2+SbF6- and crystalline CF3SCl2+SbF6- with the monoclinic space group P21/c with a = 773.5(14) pm, b = 954.8(15) pm, c = 1242.0(18) pm, β = 100.24(8)°, Z = 4.
    Notizen: Die Darstellung von CF3SClF+MF6- (M = As, Sb) erfolgt durch oxidative Fluorierung von CF3SCl mit XeF+MF6-. Das Salz wird schwingungs- und NMR-spektroskopisch charakterisiert, orientierend an den bekannten Daten von CF3SF2+MF6- und CF3SCl2+MF6-. In einer SO2-Lösung symmetrisiert sich CF3SClF+SbF6- zu CF3SF2+SbF6- und einkristallinem CF3SCl2+SbF6- mit der monoklinen Raumgruppe P21/c, a = 773,5(14) pm, b = 954,8(15) pm, c = 1242,0(18) pm, β = 100,24(8)°, Z = 4.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895730118
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  • 92
    Digitale Medien
    Digitale Medien
    Zwei neue Rubidiumlithiumzincate: RbLiZnO2 und RbLiZn2O3 (mit einer Bemerkung über CsLiZnO2) (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 568 (1989), S. 136-146 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: New Rubidium Lithium Zincates: RbLiZnO2 and RbLiZn2O3For the first time colourless single crystals of RbLiZnO2 (A) and RbLiZn2O3 (B) have been prepared. Both crystallize tetragonally, A: space group I4/mmm, Z = 2, a = 351.84(4), c = 1153.3(2) pm; B: space group P42/mnm, Z = 4, a = 1 033.8(1), c = 342.8(1) pm. The crystal structures have been determined from four circle diffractometer data (MoKα; A: 155 hkl, R = 7.9%, Rw = 7.6%; B: 384 hkl, R = 7.0%, Rw = 4.6%). RbLiZnO2 has the BaZn2P2 type of structure while RbLiZn2O3 exhibits a new structure type with linear chains of face shared cubes ∞1[O4/2RbO4/2RbO4/2] as characteristic feature. For both oxides the Madelung part of lattice energy (MAPLE), and effective coordination numbers (ECoN) are calculated.
    Notizen: Neu dargestellt wurden die Oxide RbLiZnO2 (A) und RbLiZn2O3 (B) in Form farbloser Einkristalle durch Tempern entsprechender Gemenge der binären Oxide. Beide Zincate kristallisieren tetragonal, A: Raumgr. I4/mmm, Z = 2, a = 351,84(4), c = 1153,3(2) pm; B: Raumgr. P42/mnm, Z = 4, a = 1 033,8(1), c = 342,8(1) pm. Die Kristallstrukturen wurden aus Vierkreisdiffraktometerdaten (MoKα) bestimmt (A: 155 hkl, R = 7,9%, Rw = 7,6%; B: 384 hkl, R = 7,0%, Rw = 4,6%). RbLiZnO2 kristallisiert im BaZn2P2-Strukturtyp, RbLiZn2O3 zeigt eine neue Struktur mit charakteristischen Würfel-Doppelketten ∞1[O4/2RbO4/2RbO4/2]. Der Madelunganteil der Gitterenergie (MAPLE) sowie effektive Koordinationszahlen (ECoN) wurden jeweils berechnet.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895680116
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  • 93
    Digitale Medien
    Digitale Medien
    Zur Kenntnis des α-NaFeO2-Types: Über KPrO2 [1] (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 568 (1989), S. 147-150 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: On the α-NaFeO2-Type: On KPrO2For the first time we obtained yellow-green single crystals of KPrO2 by annealing K2PrO3 in Ni-cylinders [1 000°C; 4 weeks]. The structure determination confirms the trigonal rhombohedral α-NaFeO2-type: a = 365.11(3), c = 1 859.65(21) pm, c/a = 5.09, Z = 3, spacegroup R3m, fourcircle diffractometer data (Philips PW 1100), MoKα, 134 Io(hkl), R = 2.58%, Rw = 2,42%.
    Notizen: Erstmals erhielten wir gelbgrüne Einkristalle von KPrO2 durch Tempern von K2PrO3 in Ni-Bömbchen [1000°C; 4 Wochen]. Es liegt der trigonal-rhomboedrische α-NaFeO2 Typ vor: a = 365,11(3), c = 1 859,65(21) pm, c/a = 5,09, Z = 3, Raumgruppe R3m, Vierkreisdiffraktometerdaten (Philips PW 1100), MoKα, 134 Io(hkl), R = 2,58%, Rw = 2,42%.
    Zusätzliches Material: 5 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895680117
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  • 94
    Digitale Medien
    Digitale Medien
    Herstellung keramischer Pulver. II. Über die Bildung von Mg2TiO4, MgTiO3 und MgTi2O5 durch Hydrolyse von 2-Ethoxyethylaten (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 208-214 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Preparation of Ceramic Powders. II. Mg2TiO4, MgTiO3, and MgTi2O5 Formed by Hydrolysis of 2-EthoxyethylatesSolutions of 2-ethoxyethylates of magnesium and titanium in 2-ethoxyethanol submitted to hydrolysis, evaporation and heating of the residue up to 450°C allow to prepare Mg2TiO4, MgTiO3, and MgTi2O5 in an amorphous state with smaller than 1% of volatile components. Highly dispersed powders showing an increased sintering activity are obtained as a result of recrystallization. Mg2TiO4 is formed as inverse spinel phase in a metastable state.
    Notizen: Die 2-Ethoxyethylate von Magnesium und Titan bilden in 2-Ethoxyethanol stabile Lösungen, deren Hydrolyse nach dem Abdestillieren des Lösungsmittels und Erhitzen des Rückstandes bis auf 450°C die Herstellung von Mg2TiO4, MgTiO3 und MgTi2O5 im amorphen Zustand mit weniger als 1% flüchtigen Bestandteilen gestattet. Die Rekristallisation führt zu hochdispersen sinteraktiven Pulvern, im Fall von Mg2TiO4 zur Bildung der inversen Spinellphase unter metastabilen Bedingungen.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895730121
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  • 95
    Digitale Medien
    Digitale Medien
    The electrochemical synthesis of neutral Nickel(II) Complexes of Schiff Base Ligands: The crystal structure of bis-{N-[2-(2-pyridyl)ethyl]salicylideneiminato}nickel(II) trihydrate (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 215-222 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Elektrochemische Synthese von neutralen Nickel(II)-Komplexen mit Schiffschen Basen: Kristallstruktur von Bis-{N-[2-(2-pyridyl) äthyl]-salicylideneiminato}nickel(II) TrihydratNickel(II)-Komplexe mit im Pyridin-Ring substituiertem N-2-(2-pyridyl)-äthyl-salicylideneiminat wurden durch Elektrolyse einer nicht wäßrigen Lösung des entsprechenden Liganden hergestellt; als Anode diente ein Ni-Draht. Die Struktur von Bis-{N-[2-(2-pyridyl)äthyl]-salicylideneiminato}nickel(II). Trihydrat wurde röntgenographisch bestimmt. Der Komplex kristallisiert triklin in der Raumgruppe P1 mit den Gitterkonstanten a = 13,055(4) Å, b = 13,097(6)Å, c = 16,189(5) Å, α = 102,92(3)°, β = 99,80(3)°, γ = 90,42(3)° und Z = 4. Eine Least-squares-Verfeinerung führte zu einem R-Wert von 0,047. Das Molekül ist nicht zentrosymmetrisch, da die zwei dreizähnigen Liganden eine meridionale Konfiguration um das oktaedrisch koordinierte Nickel(II) annehmen.
    Notizen: Nickel(II) complexes with N-2-(2-pyridyl)ethyl-ring substituted salicylideneiminatos have been synthesized by an electrochemical procedure using a sacrificial anode in non-aqueous solution of the corresponding ligand. The structure of bis{N-[2-(2-pyridyl)]-salicylideneiminato}-nickel (II) trihydrate has been determined by X-ray diffraction. Crystals are triclinic, space group P1, with four formula units in a cell of dimensions a = 13.055(4) Å, b = 13.097(6) Å, c = 16.189(5) Å, and α = 102.92(3)°, β = 99.80(3)°, γ = 90.42(3)°. Full matrix least squares refinement on R converged with a conventional agreement factor of 0.047. The molecule is non-centrosymmetric with two terdentate ligands in a meridional configuration around octahedral nickel(II).
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895730122
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  • 96
    Digitale Medien
    Digitale Medien
    Beiträge zur Untersuchung anorganischer nichtstöchiometrischer Verbindungen. XXXVIII. Quaternäre Nioboxidfluoride des Cadmiums und Mangans mit LiNb6O15F-Struktur (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 240-240 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895730125
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  • 97
    Digitale Medien
    Digitale Medien
    Pollucite- and Leucite-related Phases: A2BX5O12 and ACX2O6 (A = K, Rb, Cs; B = Be, Mg, Fe, Co, Ni, Cu, Zn, Cd; C = B, Al, Ga, Fe, Cr; X = Si, Ge) (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 223-230 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Pollucit- und Leucit-verwandte Phasen: A2BX5O12 und ACX2O6 (A = K, Rb, Cs; B = Be, Mg, Fe, Co, Ni, Cu, Zn, Cd; C = B, Al, Ga, Fe, Cr; X = Si, Ge)Darstellung und kristallographische Daten von 29 neuen Phasen dieser Strukturfamilie werden angegeben. Ein Überblick über die gesamte Strukturfamilie, die bis jetzt 59 Phasen enthält, wird gegeben. Die Familie enthält wenigstens sieben Strukturvarianten, von denen zwei die Pollucit-, CsAlSi2O6, und Leucit-, KAlSi2O6, Struktur sind. Beziehungen zwischen der Kationengröße und dem Strukturtyp werden vorgestellt. Ungewöhnliche Variationen in den Größen der Einheitszelle als Funktion der Kationengröße werden diskutiert, und auf die mögliche Bedeutung für das „partially collapsed framework“-Konzept von Taylor und Henderson wird hingewiesen.
    Notizen: Synthesis and crystallographic data on 29 new phases in this family are given. A survey of the crystal chemistry of the complete family, containing 59 phases to date, is presented. The family contains at least seven structural variations, two of which are the pollucite, CsAlSi2O6 and leucite, KAlSi2O6 structures. Correlations between cation size and structure type are presented. Unusual variations in unit cell dimensions as a function of cation size are discussed and the possible relevance of the „partially collapsed framework“ concept of Taylor and Henderson indicated.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895730123
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  • 98
    Digitale Medien
    Digitale Medien
    Untersuchungen zur heterogen-katalysierten Ringalkylierung von Toluen mit Methanol an modifizierten ZSM-5-Zeolithen (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 231-239 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Studies of the Heterogeneous Catalytical Ring Alkylation of Toluene with Methanol on Modified Zeolites ZSM-5Various ways for controlling the catalytic activity, the shape selectivity, and the deactivation behaviour of modified zeolites ZSM-5 has been shown by the example of the heterogeneous catalytical conversion of toluene with methanol. The preferred formation of the industrially interesting para-xylene is possible by use of ZSM-5-zeolites composed of large crystals, by dealumination of the external surface after hydrothermal treatment, by poisoning of external active centres after impregnation with inorganic salts as well as by isomorphic incorporation of boron for silicon and/or aluminium in the zeolite framework.
    Notizen: Am Beispiel der heterogen-katalysierten Umsetzung von Toluen mit Methanol wurden verschiedene Wege zur Steuerung der katalytischen Aktivität, der Formselektivität und des Desaktivierungsverhaltens modifizierter H-ZSM-5-Zeolithe aufgezeigt. Eine Ausprägung der bei der Toluenmethylierung technisch interessanten para-Xylen-Selektivität gelingt durch den Einsatz von großkristallinen ZSM-5-Zeolithen, durch Dealuminieren der äußeren Oberfläche mittels hydrothermaler Behandlung, durch Vergiften äußerer aktiver Zentren mittels Tränkung anorganischer Salze sowie durch den isomorphen Einbau von Bor für Silicium und/oder Aluminium im Zeolithgerüst.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895730124
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  • 99
    Digitale Medien
    Digitale Medien
    Die Reaktion von Trichloracetyltrischwefeltrinitrid mit Molybdänpentachlorid. Die Kristallstrukturen von CCl3CO-NS3N2 und (PPh4)2[MoCl3(N2SCOCCl3)]2 · 2CH2Cl2 · 2CCl4 Z. anorg. allg. Chem. 562 (1988) 31 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 240-240 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895730126
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  • 100
    Digitale Medien
    Digitale Medien
    Synthese und Charakterisierung von Sulfinato-Nickel(II)-Komplexen (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 240-240 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19895730127
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