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  • 1985-1989  (3,803)
  • 1975-1979  (4,326)
  • Inorganic Chemistry  (7,178)
  • Ultrastructure  (951)
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Years
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Co-localization of islet amyloid polypeptide and insulin in the B cell secretory granules of the human pancreatic islets (1989)
    Springer
    Diabetologia 32 (1989), S. 240-244 
    Details
    ISSN: 1432-0428
    Keywords: Islet amyloid polypeptide ; Pancreatic islets ; B cells ; Ultrastructure ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Islet amyloid polypeptide is a novel 37 amino-acid-residues polypeptide which has been isolated from amyloid deposits in an insulinoma, and in human and cat islets of Langerhans. The molecule has 46% homology with the calcitonin gene-related peptide. Light microscopy examination of the pancreas shows that islet amyloid polypeptide immunoreactivity is restricted to the islet B cells. The present study utilized a rabbit antiserum against a synthetic peptide corresponding to positions 20–29 of islet amyloid polypeptide, a sequence without any amino-acid identity with calcitonin gene-related peptide. By applying the immunogold technique at the ultrastructural level, it was shown that both insulin and islet amyloid polypeptide immunoreactivity occurs in the central granular core of the human B cell secretory granules, while the A cells remain unlabelled. The demonstration that islet amyloid polypeptide is a granular protein of the B cells may indicate that it is released together with insulin. Further studies are necessary to evaluate the functional role of islet amyloid polypeptide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00285291
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  • 2
    Electronic Resource
    Electronic Resource
    Yolk organelles and their membranes during vitellogenesis ofXenopus oocytes (1989)
    Springer
    Development genes and evolution 198 (1989), S. 92-102 
    Details
    ISSN: 1432-041X
    Keywords: Vitellogenesis ; Xenopus oocyte ; Yolk-platelet membrane ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The yolk platelets ofXenopus laevis have been studied by thin-section and freeze-fracture electron microscopy to characterize the boundary membrane during yolk formation. Throughout vitellogenesis, large yolk platelets are in close contact with smaller nascent yolk organelles. Two types of primordial yolk platelets (I and II) have been discriminated. After membrane fusion these precursors can be completely incorporated into the main body of existing platelets, numerous yolk crystals then merge and form one uniformly stratified core. Lipid droplets are tightly attached to the membrane at all developmental stages of yolk platelets. A direct connection of endoplasmic reticulum to the membranes of yolk platelets was not observed. On freezeetching replicas, yolk-platelet membranes present fracture faces with intramembranous particles (IMP) of various sizes and a heterogeneous distribution of approximately 200–600 IMP/μm2 at the E face, and 1200–2100 IMP/μm2 at the P face. Again, this presentation of the membrane exhibits neither anastomoses to the endoplasmic reticulum, nor caveolae that exclude the uptake of yolk-containing vesicles into these yolk organelles. Proteinaceous yolk platelets tend to fracture along their periphery through the superficial layers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02447744
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  • 3
    Electronic Resource
    Electronic Resource
    Ultrastructure of the pineal gland of the monkey, Macaca fascicularis, with special reference to the presence of synaptic junctions on pinealocytes (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 151-158 
    Details
    ISSN: 1432-0568
    Keywords: Monkey ; Ultrastructure ; Pinealocytes ; Axon terminals ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present study described the normal ultrastructure of the monkey pineal gland. The gland was composed of the principal pinealocytes, intramural neurons and glial cells. The nucleus of the pinealocytes was deeply infolded with evenly distributed chromatin materials. The abundant cytoplasm was rich in organelles including the well-developed Golgi apparatuses, multivesicular bodies, dense-cored vesicles and widely scattered free and polyribosomes. A variety of axon terminals was observed and the majority of them contained pleomorphic agranular vesicles with a few large dense-cored vesicles. A few terminals showed flattened vesicles or small dense cored vesicles. Some of the axon terminals formed synaptic contacts with the cell bodies of pinealocytes. These synapses were mainly concentrated in the posterior third of the gland. The occasional intramural neurons observed were postsynaptic to axon terminals containing round agranular vesicles. The sources of the nerve fibres and terminals forming synaptic junctions with pinealocytes and intramural neurons were discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00309766
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  • 4
    Electronic Resource
    Electronic Resource
    Measurements of the DNA amount in mono- and binucleate cells in the celiac superior mesenteric ganglion of the guinea pig (1989)
    Springer
    Anatomy and embryology 179 (1989), S. 587-590 
    Details
    ISSN: 1432-0568
    Keywords: Sympathetic ganglion ; Binucleate cells ; Ultrastructure ; Feulgen staining ; Computerized image analysis ; DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The relative proportion, ultrastructure and DNA-content of the binucleate cells in the celiac superior mesenteric ganglion of the guinea pig was studied using light and electron microscopy as well as computerized image analysis of Feulgen stained cells. The number of mono — versus binucleate cells was found to vary with stage of development with about 40% of the cells being binucleate in adult animals and 50% in late prenatal stage. No difference in ultrastructure was observed between the nuclei of the two cell types. The binucleate cells contain twice the amount of DNA found in the mononucleate cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315700
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  • 5
    Electronic Resource
    Electronic Resource
    On the presence of reciprocal synapses in the paratympanic organ of the chicken (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 175-178 
    Details
    ISSN: 1432-0568
    Keywords: Paratympanic organ ; Reciprocal synapses ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The innervation pattern of the paratympanic organ was studied by TEM. The paratympanic organ is a small tapering vesicle, typical of birds, situated in the medial wall of the tympanic cavity; it contains hair cells which are similar to type II receptors of the acoustic-lateral system; these cells are characterised by synapses which are not only afferent and efferent, as previously described, but also reciprocal with efferent fibers. Our observation revealed some efferent nerve fibers which form a relationship with hair cells containing synaptic bodies situated next to the plasma membrane and near the fibers themselves. Since synaptic bodies are commonly considered to be the site where the transmission of the impulse from the receptor to the nerve fiber takes place, our pictures suggest that the efferent fibers and hair cells may be either presynaptic or postsynaptic with respect to each other in the paratympanic organ. The hypothesis is formulated that reciprocal synapses allow interaction between hair cells, thus determining an increase in the contrast of information sent by the paratympanic organ to the CNS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00309769
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  • 6
    Electronic Resource
    Electronic Resource
    Fetal membranes and placenta of the african green monkey (Cercopithecus aethiops) (1989)
    Springer
    Anatomy and embryology 179 (1989), S. 591-604 
    Details
    ISSN: 1432-0568
    Keywords: Fetus ; Membranes ; Placenta ; Green monkey ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study examined developmental changes in fetal membranes and placenta of Cercopithecus aethiops from a Carnegie developmental stage 12 embryo to nearterm fetuses. Ultrastructurally, yolk sac cells (endoderm and mesothelium) were similar to comparable stages in other primates. Endodermal cells had few apical microvilli, abundant rough-endoplasmic reticulum, electron dense mitochondria and dense bodies. In contrast, mesothelial cells were squamous with numerous microvilli, small mitochondria and a few short strands of rough endoplasmic reticulum. Amnion cells early in gestation were squamous with few microvilli, large glycogen deposits and poorly developed cytoplasmic components. Tight junctions and desmosomes held adjacent cells together. The basal surface was smooth and the basal lamina was distinct. As development proceeded the amniotic cells became cuboidal and possessed numerous microvilli. Cytoplasmic organelles were better developed and glycogen deposits increased by mid-gestation. A thick layer of microfibrils and collagen fibers was prominent below the basal lamina. Near-term, the glycogen had virtually disappeared and the amount of lipid droplets increased. Basal infoldings and podocytic processes and the extracellular matrix had increased. The smooth chorion consisted of pseudostratified columnar cells. Cells had short microvilli, numerous granules and vesicles of variable size and electron density in early gestation. With increasing age, amounts of granules and vesicles decreased, as the endoplasmic reticulum became prominent. The chorionic trophoblast was a continuous layer in mid-pregnancy and its cells had well-developed organelles and inclusions. Late in gestation, the trophoblastic layer became discontinuous and wide intercellular spaces and channels were present. In the placenta, the trophoblastic elements showed features characteristic of primate placenta.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315701
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  • 7
    Electronic Resource
    Electronic Resource
    A comparative ultrastructural study of in vivo versus in vitro fertilization of bovine oocytes (1989)
    Springer
    Anatomy and embryology 179 (1989), S. 435-442 
    Details
    ISSN: 1432-0568
    Keywords: Ultrastructure ; In vitro fertilization ; Bovine ; Ova ; Cortical granules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Heifers were superovulated by PMSG or FSH, and oestrus was induced by prostaglandin. One group of animals was ovariectomized 19–26 h after the LH peak, the content of preovulatory follicles aspirated, and the oocytes processed for in vitro fertilization. Another group was inseminated and ova were collected from the oviducts for study of in vivo fertilization. All ova were examined ultrastructurally. The developmental rate following in vitro fertilization was delayed compared to fertilization in vivo. A high proportion of the in vitro fertilized ova showed polyspermic penetration of the zona pellucida, and supernumerary spermatozoa were found in the ooplasm of some ova. In vivo fertilization was associated with release and subsequent dispersal of the cortical granule content in the perivitelline space. In contrast to this the released granule content of the in vitro fertilized ova remained undispersed close to the oolemma. This feature may account for the high incidence of polyspermic penetration of the zona pellucida. In addition, the study provided an ultrastructural visualization of the initial contact between the equatorial segment of the spermatozoon and the microvilli of the oocyte, and the subsequent internalization of the sperm head.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319585
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  • 8
    Electronic Resource
    Electronic Resource
    Effects of continuous light on rat parotid gland structure and reactivity (1989)
    Springer
    Anatomy and embryology 179 (1989), S. 497-501 
    Details
    ISSN: 1432-0568
    Keywords: Parotid gland ; Ultrastructure ; Amylase ; Secretion ; Isoproterenol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of continuous light on ultrastructural organization and sympathetic secretory responses of the rat parotid gland are reported. After 50 days of continuous light exposure, the fine structure of the parotid gland exhibited features of enhanced secretory activity as judged by the striking development of rough endoplasmic reticulum and Golgi complexes, the depletion of secretory granules and the increased turnover of secretory cells. The secretory responses of parotid gland to isoproterenol revealed that continuous light induced a 30% increase in amylase release. This secretory hyperactivity appears to be related to a postsynaptic supersensitivity of sympathetic fibers of the autonomic nervous system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319593
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  • 9
    Electronic Resource
    Electronic Resource
    Ultrastructural study of the endocrine cells of the gut of Testudo graeca (Chelonia) (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 103-108 
    Details
    ISSN: 1432-0568
    Keywords: Ultrastructure ; Gut ; Endocrine cells ; Testudo graeca ; Chelonia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The digestive tract of Testudo graeca (Chelonia) was investigated by means of electron microscopy using both conventional and immunocytochemical techniques. EC-, L-, D-, G-, B-, N- and EC-L-cells were detected. These cells share several common ultrastructural characteristics with the endocrine cells of mammals (i.e. clear cytoplasm, prominent Golgi apparatus, secretory granules etc.). EC and D1 cells have so far not been described in the esophagus of any animal species; in the present study these cells have been observed in the esophagus of T. graeca. Of special interest was the presence of B-cells in the intestine, suggesting that the migration of B-cells from the gut to the pancreas to constitute pancreatic islets is not concluded in T. graeca. The present study demonstrates that the gut endocrine system of T. graeca is a complex structure containing a large variety of endocrine cell types similar in morphology to those found in higher vertebrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00321906
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  • 10
    Electronic Resource
    Electronic Resource
    Influence of conventionalization on cecal wall structure of germ-free Wistar rats: quantitative light and qualitative electron microscopic observations (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 191-198 
    Details
    ISSN: 1432-0568
    Keywords: Cecum ; Germ-free rat ; Microflora inoculation ; Morphometry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The structural changes of the cecal wall in germfree rats were observed at regular intervals after the inoculation of fecal microflora from conventional rats. Quantitative light microscopy showed that most of the elements in the cecal wall increased at 12 or 24 h and reached peak values at 4 days after inoculation. On the 7th day, they decreased approximately to the values for conventional rats. The crypts were bent or widely open till 24 h but were not after the 4th day. Hyperplasia of the crypt epithelial cells including mucous-type cells was observed following microbial inoculation. Electron microscopy revealed that most of the epithelial cells lining the mucosa were typical columnar cells. Desquamation of the epithelial cells and contraction of the muscle fibers were often seen on 4th day. The mucous-type cells were divided into two types, goblet and non-goblet mucous-type cells. Reduction of cecal volume after microbial inoculation may be mainly caused by muscle contraction in the early period and hyperplasia and desquamation of the epithelial cells may suggest their role as the first and non-specific defense line prior to operation of the specific immune system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00309771
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  • 11
    Electronic Resource
    Electronic Resource
    Reappraisal of neurofibrillary tangles (1989)
    Springer
    Acta neuropathologica 77 (1989), S. 258-266 
    Details
    ISSN: 1432-0533
    Keywords: Neurofibrillary tangles ; Alzheimer's disease ; Pick bodies ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We have studied the immunohistochemical reactivity and ultrastructure of both neurofibrillary tangles (NFTs) occurring with severe neurofibrillary diseases, and Pick bodies (PBs) associated with Pick's disease. The NFTs and PBs did not react immunohistochemically with the anti-nonphosphorylated neurofilament monoclonal antibody irrespective of whether they were pretreated with alkaline phosphatase. In granular neurons of the dentate fascia of Ammon's horn in cases of dementia of the Alzheimer type (DAT), NFTs either resembled PB-like inclusion bodies (Horoupian's inclusion bodies) in form, or had a perinuclear structure. Immunohistochemically and ultrastructurally, the NFTs in the dentate fascia in cases of DAT, including Horoupian's inclusion bodies, were similar to the NFTs in the pyramidal neurons of Ammon's horn, which are found most frequently in association with severe neurofibrillary diseases. Under a light microscope, Horoupian's inclusion bodies and PBs could not be differentiated and appeared to be argyrophilic round cytoplasmic inclusions in granular neurons of the dentate fascia. There were, however, ultrastructural differences. Horoupian's inclusion bodies consisted of bundles made up of straight tubules (STs), each about 15 nm in diameter. These bundles were intermixed with a few paired helical filaments which occurred at intervals of about 80 nm. On the other hand, PBs were composed of randomly distributed 15-nm-wide STs, intermixed with a very few fibrillary structures. These fibrils had a periodicity of about 160 nm, and ranged in width from about 15 nm to 30 nm. Horoupian's inclusion bodies associated with DAT and PBs associated with Pick's disease are different in this neuropathological aspect. The NFTs, including Horoupian's inclusion bodies in the dentate fascia in cases of DAT, are considered to be a manifestation of neurofibrillary degeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687577
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  • 12
    Electronic Resource
    Electronic Resource
    Malignant melanotic neuroectodermal tumor arising from the pineal body (1989)
    Springer
    Acta neuropathologica 77 (1989), S. 654-658 
    Details
    ISSN: 1432-0533
    Keywords: Melanotic neuroectodermal tumor ; Immunohistochemistry ; Ultrastructure ; Pineal origin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of a melanotic neuroectodermal tumor arising from pineal region of a 4-year-old girl is presented. The tumor had spread diffusely to the meninges, consistent with malignant behavior. Histologically, the tumor consisted primarily of epithelial elements arranged in tubules, cords and nests separated by fibrous vascular tissue in addition to a small neuroblastomatous focus. Melanin pigment was frequently observed in the epithelial tumor cells, and melanin-laden macrophages were also often observed. No teratoid elements were found. Immunohistochemically, tumor cells were positive for neuron-specific enolase but were nonreactive for S-100 protein, epithelial membrane antigen, glial fibrillary acidic protein, vimentin, α-fetoprotein and human chorionic gonadotrophin. Ultrastructurally, the epithelial nature of the tumor cells could be easily demonstrated. In addition, melanosomes in various stages in maturation were observed, indicating melanogenesis of the tumor. On the basis of the tumor location and the histological similarities previously observed for the fetal pineal body, it is very likely that this melanotic epithelial tumor could have originated from the fetal pineal gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687894
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  • 13
    Electronic Resource
    Electronic Resource
    Membranous changes in primary malignant CNS lymphomas (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 86-93 
    Details
    ISSN: 1432-0533
    Keywords: Primary malignant CNS lymphoma ; Ultrastructure ; Intracytoplasmic tubuloreticular, membranous structures ; Intranuclear inclusions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural studies of 17 primary malignant CNS lymphomas revealed 6 tumors with abnormal intracytoplasmic and/or intranuclear membranous structures, most frequently, associated with the endoplasmic reticulum or perinuclear envelope. In most cases, tubuloreticular inclusions and paired cisternae were present. Less frequent were accumulation of mictotubules, concentric lamellar bodies, and rod-like or paracrystalline intranuclear inclusions. The specificity and significance of these membranous structures remain questionable because of their frequent occurrence in a variety of normal and pathological conditions. Some of these changes may be considered as cellular reactions to viral infections, others may indicate cellular activity or degeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00308962
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  • 14
    Electronic Resource
    Electronic Resource
    Dithiobiuret neurotoxicity: an ultrastructural investigation of the lesion in preterminal axons and motor endplates in the rat lumbrical muscle (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 72-85 
    Details
    ISSN: 1432-0533
    Keywords: 2,4-Dithiobiuret ; Thioimidodicarbonic diamide ; Motor endplate ; Neuromuscular junction ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 2,4-Dithiobiuret was given i.p. to rats for 4 days at a daily dosage of 1 mg/kg and the development of the lesion associated with neuromuscular dysfunction studied in hindlimb lumbrical muscles. The first morphological indication of neurointoxication was the appearance in some motor endplates of masses of branching tubular smooth endoplasmic reticulum (SER) on day 2 which correlated with the initial functional disturbances. By the 3rd day, most motor endplates were distended by accumulations of densecored, lucent and synaptic vesicles, abnormally swollen mitochondria, intermediate filaments and branching, tubular SER. Evidence of collateral axonal sprouting was seen first at this time. On days 4 and 5, many motor endplates were markedly enlarged and showed axoplasmic organelle congestion. A significant increase in synaptic vesicle size was noted at these times in some terminals. Interposition of Schwann cell processes between the pre- and postsynaptic membranes and terminal retraction was now evident. Some intramuscular nerves showed hydropic Schwann cell cytoplasm with separation of the outermost myelin lamellae, mitochondrial swelling and adaxonal vacuoles as early as the 1st day. Proliferation and segregation of SER around central cores of neurofilaments was seen in myelinated nerve fibres and preterminals on the 3rd day. At this and later times accumulations of SER and swollen mitochondria were found at sites of axonal varicosities and at the paranodal constrictions at nodes of Ranvier. These ultrastructural data are discussed with regard to reduced terminal Ca2+ content (demonstrated by oxalate-pyroantimonate cytochemistry) and compared with the sequelae of botulinum intoxication.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687405
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  • 15
    Electronic Resource
    Electronic Resource
    Neuroendocrine markers in central nervous system neuronal tumors (gangliocytoma and ganglioglioma) (1989)
    Springer
    Acta neuropathologica 77 (1989), S. 237-243 
    Details
    ISSN: 1432-0533
    Keywords: Gangliocytoma ; Ganglioglioma ; Ultrastructure ; Immunohistochemistry ; Neuroendocrine markers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We studied five cases of central nervous system neuronal tumor, one gangliocytoma and four gangliogliomas, both ultrastructurally and immuno-histochemically, using antibodies to neuroendocrine markers including tyrosine hydroxylase (TH), serotonin (5HT), somatostatin (SOM), met-enkephalin (MEK), leu-enkephalin (LEK), substance P (SP), gastrin, vasopressin, oxytocin, vasoactive intestinal polypeptide, adrenocorticotropic hormone and calcitonin. In all cases, the presence of dense-core vesicles (60–250 nm) in the neuronal elements was the characteristic ultrastructural finding. Synapses were observed in two cases. Immunohistochemically, variable numbers of neuronal cells showed positive staining for SOM in five cases, TH, MEK and LEK in three cases, and 5HT and SP in one case each. The others were negative. Positive immunoreactivity for multiple markers was shown in all cases. SOM, TH, 5HT and SP were present in the small- to medium-sized cells, while MEK and LEK were almost exclusively confined to the large cells. Our study clearly indicated that these tumors contained neuronal cells which were not homogeneous with regard to neuroendocrine markers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687574
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  • 16
    Electronic Resource
    Electronic Resource
    A new type of neuronal cytoplasmic inclusion: histological, ultrastructural, and immunocytochemical studies (1989)
    Springer
    Acta neuropathologica 77 (1989), S. 599-604 
    Details
    ISSN: 1432-0533
    Keywords: Neuronal inclusions ; Leigh disease ; Tropomyosin ; Actin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A novel type of non-viral cytoplasmic inclusion is described, which was seen in virtually every neuron in the brain and spinal cord of a child with a presumed metabolic disorder whose clinical picture and CNS pathology were compatible with Leigh Syndrome. The ovoid to round inclusions were sharply demarcated, measuring up to 11 μm in diameter. They showed no distinctive staining with a battery of routine histological techniques. The ultrastructural features are unique, comprising non-membrane-bounded aggregates of randomly oriented plate-like structures with parallel linear densities depicting a periodicity of 11–16 nm. Immunocytochemical studies revealed strong staining with antisera to tropomyosin and weaker staining with antisera to actin. There was no reactivity with antibodies against neurofilaments, microtubules and their associated proteins, paired helical filaments, ubiquitin, vinculin or alpha-actinin. It is postulated that the metabolic disorder resulted in a neurodegenerative condition which manifested pathologically with lesions compatible with those of Leigh Syndrome. Associated with the condition was the discrete accumulation of cytoplasmic proteinaceous components, including tropomyosin, in the form of neuronal cytoplasmic inclusions possibly resulting from an alteration of the neuronal cytoskeleton.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687887
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  • 17
    Electronic Resource
    Electronic Resource
    Acute ultrastructural response of hypoxic hypoxia with relative ischemia in the isolated brain (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 637-648 
    Details
    ISSN: 1432-0533
    Keywords: Cerebral hypoxia ; Cerebral ischemia ; Ultrastructure ; Neocortex ; Brain isolation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The acute cortical response to surgical brain isolation and subsequent extracorporal normoxic or 30 min hypoxic (PaO2=20 mm Hg) perfusions (hypoxic hypoxia with relative ischemia) was evaluated. Cerebral blood flow, arterial pH and CO2 were maintained constant during both perfusions; only the arterial oxygen content was changed. The isolated brain model used in this and previous investigations produces no qualitative ultrastructural changes in the neocortex following brain isolation and normoxic perfusion. However, the acute cortical structural response to 30 min of hypoxic hypoxia with relative ischemia demonstrated a number of important observations. Hypoxic hypoxia produced ultrastructural responses common to cerebral ischemia such as nuclear chromatin clumping, nucleolar condensation and cytoskeletal breakdown. Although neuronal abnormalities seen after 30 min of hypoxic hypoxia were similar to those acute neuronal changes observed following complete cerebral ischemia without recirculation, they differed three ways: (a) mitochondrial swelling and microvacuolation were observed in many cortical pyramidal neurons. (b) Glycogen particles within astroglial processes were observed even after a 30-min period of hypoxic hypoxia. (c) Perivascular astroglial swelling was minimal despite considerable perineuronal swelling. In contrast, incomplete cerebral ischemia produces mitochondrial changes similar to those in hypoxic hypoxia but also causes the depletion of tissue glycogen and perivascular glial swelling. Thus, hypoxic hypoxia with relative ischemia produces a unique acute ultrastructural response compared to either complete or incomplete cerebral ischemia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691291
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  • 18
    Electronic Resource
    Electronic Resource
    Cytomembranous inclusions in the peripheral nerves in AIDS (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 336-339 
    Details
    ISSN: 1432-0533
    Keywords: AIDS ; Cytomembranous inclusions ; Tubuloreticular inclusions ; Ultrastructure ; Peripheral nerve
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We report finding tubuloreticular inclusions (TRI) in the endothelial cells of endo- and epineurial vessels in the sural nerve of 11 patients with AIDS. Six patients had a painful peripheral neuropathy, one a non-painful sensory neuropathy, one an acute inflammatory demyelinating polyradiculoneuropathy and one a thalidomide-related neuropathy. Two patients had no clinical evidence of neuropathy. The TRI are not specific to one neuropathy and are unlikely to contribute to the pathogenesis of peripheral nerve syndromes in AIDS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294672
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  • 19
    Electronic Resource
    Electronic Resource
    Ultrastructural changes in skeletal muscle in ovine muscular dystrophy (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 168-175 
    Details
    ISSN: 1432-0533
    Keywords: Muscular ; Dystrophy ; Ovine ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The initial ultrastructural changes in skeletal myofibers in ovine muscular dystrophy (MD) consisted of focal degeneration of myofibrils and the formation of Z-disc abnormalities, including nemaline rods, in adjacent sarcomeres. Peripheral and central sarcoplasmic masses, which occurred initially in large diameter fibers, contained a mixture of normal organelles and abnormal tubular and fibrillar formations. Vesiculate sarcolemmal nuclei with prominent nucleoli accumulated in central and subsarcolemmal locations in small clusters and short rows. Deformed individual nuclei were sometimes present within nuclear rows. Loss of the myofibrillar mass, increased density of small spherical nuclei, collections of fibrillar and tubular arrays, excessive folding of the sarcolemma and greatly reduced fiber diameter were seen in the end stage of the dystrophic process. Resting satellite cells were present at all stages of lesion development. The morphological progression of the lesions suggested an inherited inability to effectively replace lost myofibrils with ultimate exhaustion of the capacity for repair followed by pathological fiber atrophy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294375
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  • 20
    Electronic Resource
    Electronic Resource
    Microscopic examination and fatty acid characterization of filamentous bacteria colonizing substrata around subtidal hydrothermal vents (1989)
    Springer
    Archives of microbiology 152 (1989), S. 64-71 
    Details
    ISSN: 1432-072X
    Keywords: Thiothrix sp. ; Beggiatoa sp. ; Sulfideoxidizing ; Polyunsaturated ; Fatty acids ; Inclusions ; Sheath ; Southern California ; Ultrastructure ; Sulfur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Microscopic examination of the whitish mat that covered the substrata around subtidal hydrothermal vents at White Point in southern California revealed a “Thiothrix-like” bacterium containing sulfur inclusions as the dominant filamentous form in this microbial community. The matlike appearance developed as a result of the closely-packed manner inwhich the basal ends of the filaments were anchored to the substrate. The dominant phospholipid fatty acids of these filaments (16:0, 16:1w7c, 18:0, 18:1w7c) were similar to those recovered from a sample of Beggiatoa isolated from a spring in Florida. Filaments from both sources contained small quantities of C18 and C20 polyunsaturated fatty acids, as well. A larger but less abundant sheathless, filamentous form, which also contained sulfur inclusions and displayed a cell wall structure similar to a previously described Thioploca strain, also colonized the substrata around the subtidal mat. The preservation methods used in the preparation of thin-sections of the subtidal mat material were found to be inadequate for defining some key cellular structures of the large filaments. Nevertheless, the results demonstrate that the filamentous bacteria comprising the microbial mat in the vicinity of the subtidal vents exhibit some of the features of the free-living filamentous microorganisms found in deep-water hydrothermal areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00447013
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  • 21
    Electronic Resource
    Electronic Resource
    The ultrastructure of chemolithoautotrophic Gallionella ferruginea and Thiobacillus ferrooxidans as revealed by chemical fixation and freeze-etching (1989)
    Springer
    Archives of microbiology 151 (1989), S. 245-251 
    Details
    ISSN: 1432-072X
    Keywords: Gallionella ferruginea ; Thiobacillus ferrooxidans ; Iron bacteria ; Chemolithoautotrophy ; Ultrastructure ; Freeze-etching ; Cell wall organization ; Intracytoplasmic membranes ; Carboxysomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract By using sodium thioglycolate to dissolve the high amount of excreted stalk material in axenic cultures of the chemolithoautotrophic iron bacterium Gallionella ferruginea, the ultrastructure of Gallionella cells from pure cell suspensions could be studied without any loss of viability or disturbance by dense ferric stalk fibers, and compared with Thiobacillus ferrooxidans, also grown chemolithoautotrophically with ferrous iron as energy source. Both organisms were chemically fixed or freeze-etched. Particular structural differences between these iron-bacteria could be ascertained. G. ferruginea possesses intracytoplasmic membranes and soluble d-ribulose-1,5-bisphosphate-carboxylase, whereas T. ferrooxidans contains carboxysomes but no intracytoplasmic membranes; Gallionella forms poly-β-hydroxybutyrate and glycogen as storage material; T. ferrooxidans produces only glycogen. Both organisms also differ from each other with respect to the freeze fracture behaviour of the cell envelope layers. Whereas the cells of T. ferrooxidans exhibit a characteristic double cleavage, exposing the plasmic fracture face and exoplasmic fracture face of the outer membrane and cytoplasmic membrane, the exceptionally thin multilayered cell envelope of G. ferruginea revealed a particularly intimate association between the layers, resulting in a visualisation of the supramolecular organisation of only the inner fracture face of the cytoplasmic membrane. The results are discussed predominantly in relation to the extremely distinct environments of both organisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00413137
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  • 22
    Electronic Resource
    Electronic Resource
    Immunogold localization of coenzyme F420-reducing formate dehydrogenase and coenzyme F420-reducing hydrogenase in Methanobacterium formicicum (1989)
    Springer
    Archives of microbiology 151 (1989), S. 307-313 
    Details
    ISSN: 1432-072X
    Keywords: Methanobacterium formicicum ; Formate dehydrogenase ; F420-hydrogenase ; Immunogold ; Ultrastructure ; Methanogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ultrastructural locations of the coenzyme F420-reducing formate dehydrogenase and coenzyme F420-reducing hydrogenase of Methanobacterium formicicum were determined using immunogold labeling of thin-sectioned, Lowicryl-embedded cells. Both enzymes were located predominantly at the cell membrane. Whole cells displayed minimal F420-dependent formate dehydrogenase activity or F420-dependent hydrogenase activity, and little activity was released upon osmotic shock treatment, suggesting that these enzymes are not soluble periplasmic proteins. Analysis of the deduced amino acid sequences of the formate dehydrogenase subunits revealed no hydrophobic regions that could qualify as putative membrane-spanning domains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00406556
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  • 23
    Electronic Resource
    Electronic Resource
    Sebaceous carcinoma of the parotid gland (1989)
    Springer
    Virchows Archiv 414 (1989), S. 459-464 
    Details
    ISSN: 1432-2307
    Keywords: Sebaceous carcinoma ; Parotid gland ; Salivary gland ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sebaceous carcinoma of salivary gland origin is extremely rare and, because of its rarity, the clinicopathological characteristics and the histogenesis are not fully understood. We present a case of sebaceous carcinoma of the parotid gland which brings the total number of reported cases to 22. The tumor showed epithelial cell nests which were mainly composed of sebaceous cells with marked cellular atypia. In most of the nests, glandular spaces lined by ductal epithelium were present. Scattered mucous cells and flattened eosinophilic cells at the periphery of the nests were also seen. Ultrastructural and immunohistochemical observations of the tumour revealed coexistence of sebaceous and glandular differentiations in some tumour cells. Tumour cells with lipid granules often participated in the formation of glandular structures or exhibited intracytoplasmic lumina, and immunohistochemical localization of lactoferrin and secretory component, the functional markers of ductal epithelium of salivary gland, was demonstrated not only in duct-forming tumour cells but also in many sebaceous tumour cells. It seems likely that sebaceous carcinoma originates from pluripotential duct cells which can differentiate into sebaceous, ductal and mucous cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718631
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  • 24
    Electronic Resource
    Electronic Resource
    Paracrystalline inclusions in metaplastic ciliated cells of the human gastric mucosa (1989)
    Springer
    Virchows Archiv 415 (1989), S. 145-149 
    Details
    ISSN: 1432-2307
    Keywords: Paracrystalline inclusion ; Microtubule ; Ciliogenesis ; Gastric ciliated cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Unusual electron-dense paracrystalline inclusions were found in metaplastic ciliated cells in the stomachs of three Japanese male patients with gastric carcinoma. These patients had not been given antitumour drugs before surgery and ethrane (enflurane) was used as the anaesthetic. Ciliated cells in the gastric mucosa are found not infrequently in the pyloric glands in association with intestinal metaplasia in elderly Japanese patients. Paracrystalline inclusions were found only in the ciliated cells and never in any other types of gastric mucosal cell. These inclusions were located in the apical portion of the ciliated cells in intimate association with the basal bodies. They consisted of twisted strings about 27 nm wide with a regularly repeated spacing of about 30 nm. On highly magnified electron micrographs, granules about 4 nm in diameter were detected. These paracrystalline inclusions have never been reported previously, although their location in ciliated cells and their morphological characteristics suggest an intimate relationship with the ciliogenesis of metaplastic ciliated cells in the human stomach.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00784352
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  • 25
    Electronic Resource
    Electronic Resource
    Ultrastructure of metaplastic ciliated cells in human stomach (1989)
    Springer
    Virchows Archiv 414 (1989), S. 113-119 
    Details
    ISSN: 1432-2307
    Keywords: Gastric mucosa ; Intestinal metaplasia ; Ciliated cell ; Ciliated metaplasia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intestinal metaplasia of the gastric mucosa occurs commonly in aged Japanese patients and has been discussed in relation to the high incidence of gastric cancer in Japanese. Ciliated cells in the gastric mucosa have frequently been found in association with intestinal metaplasia in the pyloric gland and rarely in the cardiac gland in many Japanese patients, and exceptionally in one Chinese and in one Swedish patient. Electron microscopic examination of 12 Japanese patients has revealed that these structures are not metaplastic stereocilia, but true cilia. Ciliated cells have been found in the basal part of the gastric glands and never in the surface epithelium. The fine structure of the gastric cilia was almost the same as that of normal respiratory cilia. However, in the gastric cilia, most dynein arms were inconspicuous even after tannic acid fixation, indicating that ciliary beating of the gastric cilia is problematic. Abnormal cilia and basal bodies also were found. Ciliated cells have always occurred in association with intestinal metaplasia, therefore this phenomenon might be a type of metaplasia and is named “ciliated metaplasia” of the gastric mucosa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718590
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  • 26
    Electronic Resource
    Electronic Resource
    Malignant fibrous histiocytoma: Similarities to the “fibrohistiocytoid cells” in chronic inflammation (1989)
    Springer
    Virchows Archiv 414 (1989), S. 285-298 
    Details
    ISSN: 1432-2307
    Keywords: Malignant fibrous histiocytoma ; Ultrastructure ; Enzyme histochemistry ; Immunohistochemistry ; “Fibrohistiocytoid cell”
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural, enzyme histochemical and immunohistochemical studies were performed on tissue obtained from eight cases of malignant fibrous histiocytoma (MFH) and five cases of sacral decubitus ulcer. The MFH was composed of two major tumour cell types: fibroblast-like and histiocyte-like cells. Both cell types demonstrated abundant branching, fragmented rough endoplasmic reticulum (rER), many free ribosomes, occasional small mitochondria, an oval, elliptical or irregularly shaped nucleus with one or two prominent nucleoli and often a few dense bodies. However, pseudopodial projections, multivesicular bodies and phagosomes, common histiocyte organelles, were not seen. With little difference between cases or selection sites, the MFH cells reacted to acid phosphatase (AcP) and α-naphtyl butyrate esterase (ANBE) by enzyme histochemistry and with ferritin (Fer), α1-antitrypsin (AT), α1-antichymotrypsin (ACT), fibronectin (FN), HLA-DR, HLA-DP, Leu 10 and OKT 9 in immunohistochemical studies. MFH tumour cells did not immunostain with monocyte/macrophage markers (Leu M1, Leu M3, Mo 1, Mo 2 and Macrophage) although non-neoplastic histiocytes did react to these markers. In addition, granulation tissue, such as that found in sacral decubitus ulcers, was examined and the existence of a specific cell type called the “fibrohistiocytoid (FH) cell” was documented. The FH cell was short, spindle shaped and elliptical. Ultrastructurally, it had fragmented rER distributed in a branching pattern, dispersed free ribosomes, small mitochondria and a few dense bodies, but lacked diverse fused lysosomes and distinct pseudopodial cytoplasmic extensions. The FH cells reacted with AcP, alkaline phosphatase and ANBE but not with peroxidase using enzyme histochemistry and with Fer, AT, ACT, FN, HLA-DR, HLA-DP, Leu 10 and OKT 9 but not with monocyte/macrophage markers, C3d receptor, C3bi receptor in immunohistochemical studies. The FH cells had morphological, enzyme histochemical and immunohistochemical characteristics intermediate between fibroblasts and histiocytes. Similarities between MFH cells and the FH cells seen in chronic inflammation are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00734082
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  • 27
    Electronic Resource
    Electronic Resource
    Liver cell shedding and phagocytic rveaction in alcoholic liver disease (1989)
    Springer
    Virchows Archiv 415 (1989), S. 21-29 
    Details
    ISSN: 1432-2307
    Keywords: Alcoholic liver disease ; Ultrastructure ; Phagocytosis ; Cell shedding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sinusoidal macrophages were studied by light and electron microscopy in 49 liver biopsies from alcohol-abusers with a variety of alcohol-related liver lesions or with near-normal livers. Changes were related to those in nearby hepatocytes. A reduction in the number of macrophages was noted in the more severely damaged livers. Hepatocytes formed blebs at their sinusoidal poles, and these protruded into the space of Disse and into the sinusoidal lumen. It is postulated that reduced phagocytic activity in the livers of patients with severe alcohol-related liver disease leads to increased shedding of hepatocellular material into the circulation. This may promote the development of autoimmune reactions directed against hepatocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718601
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  • 28
    Electronic Resource
    Electronic Resource
    Ultrastructural study of pseudo-Kaposi's sarcoma (Bluefarb-Stewart type) (1989)
    Springer
    Archives of dermatological research 281 (1989), S. 35-39 
    Details
    ISSN: 1432-069X
    Keywords: Pseudo-Kaposi's sarcoma ; Bluefarb-Stewart syndrome ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study of the skin lesion of a young patient affected by pseudo-Kaposi's sarcoma of the Bluefarb-Stewart type (BSS) is reported. The neoplasm consisted of a proliferation of vascular structures mostly consisting of a solid bud of endothelial cells surrounded by a thinned and polystratified basement membrane and several pericytes. Both endothelial cells and pericytes were of normal ultrastructural appearance. Intervascular “stromal” cells were few and morphologically identified as macrophages and/or phagocytic fibroblasts. Masses of hemosiderin were detected outside the cells and in the macrophages, endothelial cells, and pericytes. Intracytoplasmatic crystalloid inclusions similar to those found in fetal endothelium and hemangiomas were observed in a few endothelial cells. These findings are different from those of previously reported cases of pseudo-Kaposi's sarcoma and may be helpful in distinguishing Kaposi's sarcoma from BSS. The role of immunodeficiency in the onset of BSS is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00424270
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  • 29
    Electronic Resource
    Electronic Resource
    Total muscle mitochondrial volume in relation to aerobic capacity of horses and steers (1989)
    Springer
    Pflügers Archiv 413 (1989), S. 343-347 
    Details
    ISSN: 1432-2013
    Keywords: Exercise ; Heart ; Mitochondria ; Oxygen uptake ; Respiration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The relationship between maximal oxygen consumption rate ( $$\dot V{\text{O}}_{{\text{2max}}}$$ ) and mitochondrial content of skeletal muscles was examined in horses and steers (n=3 each). Samples of the heart left ventricle, diaphragm,m. vastus medialis, m. semitendinosus, m. cutaneous thoracicus andm. masseter, as well as samples of muscles collected in a whole-body sampling procedure, were analyzed by electron microscopy. $$\dot V{\text{O}}_{{\text{2max}}}$$ per kilogram body mass was 2.7× greater in horses than steers. This higher $$\dot V{\text{O}}_{{\text{2max}}}$$ was in proportion to the higher total volume of mitochondria in horse versus steer muscle when analyzed from the whole-body samples and from the locomotor muscle samples. In non-locomotor muscles, total mitochondrial volume was greater in horses than steers, but not in proportion to their differences in $$\dot V{\text{O}}_{{\text{2max}}}$$ . The $$\dot V{\text{O}}_{{\text{2max}}}$$ of the mitochondria was estimated to be close to 4.5 ml O2·ml−1 mitochondria in both species. It is concluded that in a comparison of a highly aerobic to a less aerobic mammalian species of similar body size, a higher oxidative potential may be found in all muscles of the more aerobic species. This greater oxidative potential is achieved by a greater total volume of skeletal muscle mitochondria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00584481
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  • 30
    Electronic Resource
    Electronic Resource
    Morphology of tyrosine hydroxylase-immunoreactive neurons in the human cerebral cortex (1989)
    Springer
    Experimental brain research 76 (1989), S. 12-20 
    Details
    ISSN: 1432-1106
    Keywords: Distribution ; Ultrastructure ; Biopsy ; Catecholamines ; Interneurons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In freshly fixed biopsies of human cerebral cortex obtained at surgery, immunocytochemical staining with antibodies against tyrosine hydroxylase (the rate limiting biosynthetic enzyme for catecholamines) revealed, in addition to a dense axonal plexus, a population of immunoreactive cell bodies. The neuronal nature of these cells was ascertained by: i) the presence of a rich rough endoplasmic reticulum in the cell body and of synapses on the cell body and dendrites, and ii) the demonstration of the lack of reactivity with the astroglial marker, glial fibrillary acidic protein, in the tyrosine hydroxylase-immunoreactive cells. The tyrosine hydroxylase-immunoreactive neurons were found in all areas of cortex sampled, and were located almost exclusively in the infragranular layers. Most tyrosine hydroxylase-immunoreactive cells were bipolar and were vertically oriented, but a few had a multipolar or horizontal dendritic arbor. The dendrites of these cells were varicose and aspiny, and the axons were very thin. Tyrosine hydroxylase-immunoreactive neurons were reported to be present transiently in the developing mammalian cerebral cortex and only recently in cerebral cortex of mature mammalian brains. Internuncial neurons in the human cerebral cortex containing a catecholamine synthesizing enzyme would be significant, in particular considering that catecholamines are likely to be involved in some major mental disorders.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00253618
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  • 31
    Electronic Resource
    Electronic Resource
    Light and electron microscopic studies of calcitonin gene-related peptide-like immunoreactive terminals in the central nucleus of the amygdala and the bed nucleus of the stria terminalis of the rat (1989)
    Springer
    Experimental brain research 77 (1989), S. 217-220 
    Details
    ISSN: 1432-1106
    Keywords: Calcitonin gene-related peptide (CGRP) ; Bed nucleus of the stria terminalis ; Central nucleus of the amygdala ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light and electron microscopic analysis of calcitonin gene-related peptide (CGRP)-like immunoreactive (LI) terminals in the bed nucleus of the stria terminalis (BST) and the central nucleus of the amygdala (Ce) was carried out using the peroxidase-antiperoxidase method. CGRP-LI fibers were densely distributed in the dorsal subdivision of the lateral BST (BSTL) and the lateral and lateral capsular subdivisions of the Ce, where the CGRP-LI terminals formed symmetrical and asymmetrical axo-dendritic, and symmetrical axosomatic synapses. One of the most characteristic features of the CGRP-LI terminals was the presence of large, long boutons, each of which surrounded a cell soma and made many synaptic contacts. These findings suggest that CGRP exerts a significant influence on neurons in the BSTL and Ce.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00250584
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  • 32
    Electronic Resource
    Electronic Resource
    Encapsulated nerve corpuscles in the human tympanic membrane (1989)
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 169-172 
    Details
    ISSN: 1434-4726
    Keywords: Tympanic membrane ; Ultrastructure ; Sensory receptors ; Nerve endings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Encapsulated nerve endings were found in both the subepidermal connective tissue and the lamina propria of a human tympanic membrane. The structure of the corpuscles was round or oval and contained a number of axon terminals with mitochondria and Schwann cell processes. Amorphous materials were present in the intercellular space. These features appear to be advantageous in transmitting mechanical forces on the capsule to the axon terminals and are comparable to the function of a mechanoreceptor. Resultant changes in the shape and stiffness of the tympanic membrane as the result of its dislocation indicate similar changes in the pressure on the corpuscle. The arrangement of the sensory corpuscles suggests that they may play a role in detecting pressure changes in the middle ear cavity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00456661
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  • 33
    Electronic Resource
    Electronic Resource
    Ultrastructural localization of carbonic anhydrase in the vestibular end organs of the guinea pig (1989)
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 56-60 
    Details
    ISSN: 1434-4726
    Keywords: Carbonic anhydrase ; Vestibular organ ; Guinea pig ; Histochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Carbonic anhydrase activity was demonstrated cytochemically on an ultrastructural level in the vestibular end organs of the guinea pig. Reaction product was found in the dark cells, transitional cells, cells of the planum semilunatum and supporting cells. In the dark cells, reaction product was observed in the cytoplasm as well as in the basal infoldings. Reaction product was also observed in the basal infoldings of the transitional cells and the cells of the planum semilunatum. The globular structures inside the supporting cells, transitional cells and the cells of the planum semilunatum were also surrounded by the reaction product. These findings suggest that carbonic anhydrase may have different functions, such as water and ion transport, respiration, nutrition and calcium carbonate deposition in the vestibular end organs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00454136
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  • 34
    Electronic Resource
    Electronic Resource
    The ultrastructure of polymorphic pollen grains of Canna indica L. (1989)
    Springer
    Sexual plant reproduction 2 (1989), S. 193-198 
    Details
    ISSN: 1432-2145
    Keywords: Polymorphism ; Ultrastructure ; Pollen grains ; Canna indica L ; Tannin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Our investigations on Canna indica L. indicate that the pollen of this species is polymorphic: there are two types of pollen — a larger type and a comparatively smaller type. Transmission electron microscopy (TEM) revealed the presence of small vacuoles containing tannic substances in the generative cell (GC) of the larger grains: the GC of the mature grain contained a higher quantity of tannins than the GC of the immature grain. Mitochondria, lipid bodies, rough endoplasmic reticulum (RER) and microtubular bundles were present in the cytoplasm of the GC. Numerous mitochondria, lipid bodies and plastids were also present in the vegetative cell (VC), with the mitochondria clustered around the vegetative nucleus. The plastids were observed to be associated with the RER cisterns. During the maturation process, the number of starch grains contained in the plastids decreased.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00192766
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  • 35
    Electronic Resource
    Electronic Resource
    An electron microscope study on in vitro parthenogenesis in sunflower (1989)
    Springer
    Sexual plant reproduction 2 (1989), S. 154-166 
    Details
    ISSN: 1432-2145
    Keywords: Helianthus annuus ; Unfertilized ovule culture ; Parthenogenesis ; Ultrastructure ; Proembryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Electron microscope studies have been conducted on the parthenogenesis induced by in vitro culture of unfertilized ovules of sunflower (Helianthus annuus). In comparison with the state of the egg prior to inoculation, some eggs 5 days after culture show striking ultrastructural changes, which include, among others, nuclear migration, an increase in the number and activity of the organelles, a loss of polarity and wall formation at the chalazal end of the cell. Most of these changes are similar to those that occur normally in the zygote, indicating that parthenogenic development has been triggered in these eggs. Such eggs have been termed activated and are presumed to be capable of undergoing parthenogenesis. The parthenogenic proembryos which result share some features in common with zygotic proembryos. In addition, some parthenogenic proembryos exhibit unique properties not found in zygotic proembryos. These include embryos that consist of two parts differing markedly in density, an inversion of polarity, the frequent occurrence of autophagic vacuoles, the thickening of cell walls, a centripetal growth mode of wall formation, the appearance of an incomplete cell wall, free nuclear division, amitosis and degeneration. We believe that these ultrastructural peculiarities are the effects of in vitro culture.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00192762
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  • 36
    Electronic Resource
    Electronic Resource
    Cell mediated calcification in collagen gel cultures of fetal rat calvaria cells. Loss of gap junctions precedes calcification (1989)
    Springer
    Journal of bone and mineral metabolism 7 (1989), S. 6-17 
    Details
    ISSN: 1435-5604
    Keywords: Intercellular communication ; Gap junction ; Calcification ; Collagen gel ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To analyze the mechanism of initiation of cell-mediated calcification in hard tussue and its relationship to the frequency of gap junctions, enzymatically isolated cells from fetal rat calvaria cultured in collagen gels were observed ultrastructurally over a time course. Calcification was observed at 2–3 weeks after the initiation of culture when the seeding cellularity and the concentration of β-glycerophosphate were sufficiently high. In the collagen gels, round cells (R), spindle or stellate cells (S), and fat cells (F) were characterised morphologically. The ultrastructural features of initial calcification could be classified into 4 subtypes: 1) a large mass greater than 10 µm in diameter (Type I), 2) deposition associated with dead R cells or matrix vesicles (Type II), 3) intracellular deposition (Type III), and 4) other than Types I–III (Type IV). Type II was the most frequent (44.5%) and Type III was the least (6.8%). Gap junction was observed frequently between 1) R cells, 2) S cells, 3) between R cells and S cells. The frequency of gap junctions in collagen gels decreased statistically (X2-test; p〈0.001), when calcification was initiated. This cell culture system can be regarded as a useful model to analyze the initiation of cell mediated calcification in hard tissue. Gap junctions might function in cell communication and a decrease in their numbers could lead to cell death and, subsequently to calcification.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02399048
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  • 37
    Electronic Resource
    Electronic Resource
    Ultrastructure ofCyanoptyche gloeocystis f.dispersa (Glaucocystophyceae) (1989)
    Springer
    Plant systematics and evolution 164 (1989), S. 65-73 
    Details
    ISSN: 1615-6110
    Keywords: Algae ; Glaucocystophyceae ; Cyanoptyche gloeocystis f.dispersa ; Ultrastructure ; endocytobiosis ; cyanelles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cyanoptyche gloeocystis f.dispersa (Geitler)Starmach is a palmelloid colonial alga that contains prokaryotic blue-green endocytobionts (cyanelles) instead of chloroplasts. The periphery of the host cell shows a peculiar lacunae system with underlying microtubules. Vegetative cells possess two rudimentary flagella. Zoospores are dorsiventrally shaped with two heterokont and heterodynamic flagella which originate from a subapical depression. This depression can also be seen in vegetative cells. Both flagella possess non-tubular mastigonemes. Main reserve product is starch lying freely in the cytoplasm. Cyanelles, enclosed singly in a host vesicle, are provided with a remnant cell wall. Thylakoids are arranged concentrically. The central part of each cyanelle harbours its DNA and one large polyhedral body, probably a carboxysome.Cyanoptyche gloeocystis f.dispersa shares all taxonomically essential characters with the monadoidCyanophora, the palmelloidGloeochaete, and the coccoidGlaucocystis. All of them are members of the cyanelle-bearing small algal classGlaucocystophyceae. Members of this class serve as model organisms for the evolution of chloroplasts from cyanophycean ancestors.
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    URL: http://dx.doi.org/10.1007/BF00940430
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    Cell multiplication and ultrastructure ofMicrasterias denticulata (Desmidiaceae) grown under salt stress (1989)
    Springer
    Plant systematics and evolution 164 (1989), S. 197-208 
    Details
    ISSN: 1615-6110
    Keywords: Algae ; Chlorophyta ; Desmidiaceae ; Micrasterias ; Ultrastructure ; electron microscopy ; cell multiplication ; salt stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cells ofMicrasterias denticulata Bréb. were kept in nutrient solution of high osmolality (salt stress) for four weeks. In a special cell multiplication test it was established that cell division is gradually inhibited at increasing salt concentrations and totally arrested at the highest concentration (26 mosm/kg). “Recovery studies” proved that even cells from the highest concentration range start dividing immediately after being placed in aqua bidest. thus indicating the full reversibility of the inhibiting effect. — Cells of the highest concentration range show marked ultrastructural changes. Besides an enormous accumulation of starch and oil bodies and a condensed appearance of the ground plasma, a reduction of mitochondria, ER and the Golgi-system is found. The most striking effect occurs on the vacuolar system which appears extremely reduced and condensed. The cell wall is thickened by the formation of an additional cell wall layer with a “spongy” electron microscopical appearance. Through the cell wall many droplets of a probably fat-like substance are excreted. — In summary, salt stress induces growth-inhibited “akinete” cells in the sense ofFritsch; these can be reactivated by decreasing the salt concentration. The salt-induced “akinete state” seems to be an ecological adaption to unfavourable conditions rather than a degeneration of the cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00940437
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  • 39
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    Electronic Resource
    Comparative ultrastructure of the zoospores of nine species ofNeochloris (Chlorophyta) (1989)
    Springer
    Plant systematics and evolution 168 (1989), S. 195-219 
    Details
    ISSN: 1615-6110
    Keywords: Algae ; Chlorophyta ; Chlorophyceae ; Pleurastrophyceae ; Hydrodictyon ; Neochloris ; Pediastrum ; Sphaeroplea ; Ultrastructure ; flagellar apparatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nine species ofNeochloris can be divided into three groups on the basis of comparative ultrastructure of the flagellar apparatus, the cell wall and the pyrenoid of zoospores. In Group I,N. wimmeri andN. minuta, zoospores are thin-walled, pyrenoids are penetrated by stromal channels, and the basal bodies are in the clockwise absolute orientation and connected by the distal and two proximal fibers. In Group II,N. aquatica, N. vigenis, N. terrestris, N. pyenoidosa, andN. pseudostigmatica, zoospores are naked or covered by fuzzy material, pyrenoids are covered by a continuous starch sheath or invaginated by cytoplasmic channels, basal bodies are directly opposed, the distal fiber is differentiated into a ribbed structure at the central region, a striated microtubule-associated component (SMAC) is continuous between opposite two-membered rootlets and connected to the ribbed structure, proximal ends of basal bodies are covered by partial caps, each two-membered rootlet and a basal body are connected by a striated fiber to the X-membered rootlet associated with the opposite basal body, and the basal bodies, when oriented at wide angles, are joined at their proximal ends by core extensions. In Group III,N. pseudoalveolaris andN. cohaerens, zoospores are naked, pyrenoids are traversed by parallel thylakoids, basal bodies are in the counterclockwise absolute orientation and overlapped, and each X-membered rootlet is connected to the end of the opposite basal body by a terminal cap. It is suggested that the genusChlorococcopsis gen. nov. be erected for the Group I species. Group II, which includes the type species,N. aquatica, should be preserved asNeochloris. The group appears to be closely related to the coenobial generaPediastrum, Hydrodictyon, andSorastrum, and to have affinities with the coenocytic generaSphaeroplea andAtractomorpha as well. It is also suggested that the genusParietochloris gen. nov. be erected in thePleurastrophyceae for the species of Group III.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00936099
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  • 40
    Electronic Resource
    Electronic Resource
    Effect of disuse on the ultrastructure of the achilles tendon in rats (1989)
    Springer
    European journal of applied physiology 59 (1989), S. 239-242 
    Details
    ISSN: 1439-6327
    Keywords: Collagen fibre ; Achilles tendon ; Disuse ; Atrophy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We examined the influence exerted, through disuse of the hindlimb, on the collagen fibres of the achilles tendon in rats. With disuse the body mass decreased by 28%, and the mass of soleus muscle decreased by 20%. A decrease in the surface area and diameter was observed in the experimental group when compared to the control group. A histogram of the collagen fibres showed a decrease of the thick fibres in the experimental group. The maximum surface area of collagen fibres in the experimental group was seen to be only 43% of that of the control group. These results showed a decrease in the thickness of the collagen fibres of the achilles tendon through disuse. This seemed to suggest that resistance to tension is decreased by disuse.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02386194
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  • 41
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    Electronic Resource
    Ultrastructural responses of tobacco pollen tubes to heat shock (1989)
    Springer
    Protoplasma 153 (1989), S. 104-110 
    Details
    ISSN: 1615-6102
    Keywords: Nicotiana sylvestris ; Pollen tube growth ; Heat shock ; Ultrastructure ; Endoplasmic reticulum ; Mitochondria ; Golgi apparatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effect of elevated temperatures on semivivo growth and ultrastructure of tobacco pollen tubes was investigated. Tube growth was decreased by about 50% at 35 °C, independent of the duration of treatment, and at 40 °C and above there was no growth of tubes. Heat treatment caused ultrastructural changes like accumulation of membranous materials, concentric stacking of rough endoplasmic reticulum, reduction in vesicle production by dictyosomes, increase in the fenestrated regions of the Golgi cisternae, swelling of mitochondrial saccules and increase in the electron density of the mitochondrial matrix. Furthermore, the dictyosomes of the treated tubes showed significant increase in the number of cisternae from 30 to 45 °C. The temperature induced changes were persistant at least for 24 h in 35 °C grown pollen tubes. The possible reasons for the tube growth inhibition are discussed on the basis of the ultrastructural alterations caused by elevated temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01322470
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  • 42
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    Ultrastructural studies of spermatogenesis inAnthocerotophyta V. Nuclear metamorphosis and the posterior mitochondrion ofNotothylas orbicularis andPhaeoceros laevis (1989)
    Springer
    Protoplasma 151 (1989), S. 137-150 
    Details
    ISSN: 1615-6102
    Keywords: Bryophyte ; Notothylas ; Nuclear metamorphosis ; Phaeoceros ; Posterior mitochondrion ; Spermatogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ultrastructural observations reveal that the spermatozoids of the hornwortsNotothylas andPhaeoceros contain two mitochondria and not one as described previously. Mitochondrial ontogeny and nuclear metamorphosis during spermiogenesis in these plants differ from all other archegoniates. The discovery that the posterior region of the coiled nucleus (when viewed from the anterior aspect) lies to the left of the anterior, in striking contrast to the dextral coiling of the nucleus of spermatozoids of other embryophytes, underlines the isolated nature of the hornworts among land plants. As the blepharoplast develops, the numerous ovoid mitochondria initially present in the nascent spermatid fuse to form a single elongated organelle which is positioned subjacent to the MLS and extends down between the nucleus and plastid. At the onset of nuclear metamorphosis, the solitary mitochondrion has separated into a larger anterior mitochondrion (AM) associated with the MLS and a much smaller posterior mitochondrion (PM) adjacent to the plastid. The PM retains its association with the plastid and both organelles migrate around the periphery of the cell as the spline MTs elongate. By contrast, in moss spermatids, where mitochondria undergo similar fusion and division, the AM is approximately the same size as the PM and the latter is never associated with the spline. As in other archegoniates, except mosses, spline elongation precedes nuclear metamorphosis in hornworts. Irregular strands of condensed chromatin compact basipetally to produce an elongated cylindrical nucleus which is narrower in its mid-region. During this process excess nucleoplasm moves rearward. It eventually overarches the inner surface of the plastid and entirely covers the PM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403451
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    Electronic Resource
    Ultrastructural changes in maturing pollen grains ofApium nodiflorum L. (Apiaceae), with special reference to the endoplasmic reticulum (1989)
    Springer
    Protoplasma 152 (1989), S. 69-76 
    Details
    ISSN: 1615-6102
    Keywords: Apiaceae ; Apium nodiflorum ; Endoplasmic reticulum ; Pollen grain ; Polysaccharide particles ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructural events in 3-cellular pollen grains ofApium nodiflorum L. are investigated during pollen maturation. Three distinct developmental stages are distinguished from the formation of sperm cells up to anthesis, whereby the rough endoplasmic reticulum (RER) is mainly involved. The most conspicious form is the highly dilated RER in the vegetative cytoplasm of the youngest pollen grains, which changes to vesicular RER in the following stage. In mature pollen grains the RER has a narrow cisternal configuration and often forms stacks. Pollen activation is preceded by the accumulation of polysaccharide particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01323064
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  • 44
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    Electronic Resource
    Ultrastructure of the nitrogen-fixing, filamentous, nonheterocystous cyanobacterium,Plectonema boryanum (1989)
    Springer
    Protoplasma 152 (1989), S. 130-135 
    Details
    ISSN: 1615-6102
    Keywords: Plectonema boryanum ; Cyanobacteria ; Ultrastructure ; Nitrogen fixation ; Nitrogen starvation ; Immunogold localization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of fructose-supplemented and unsupplemented nitrogen-fixing (fix +) and nonfixing (fix −)Plectonema boryanum UTEX 581 cells was examined by transmission electron microscopy. The most prominent structural differences included the arrangement and morphology of the thylakoids and alterations in the appearance of the interthylakoidal spaces. These ultrastructural differences, together with other observations such as glycogen content and presence of nitrogenase (using acetylene reduction assay and immunogold localization), readily distinguished nonfixingP. boryanum from nitrogen-fixing cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01323072
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  • 45
    Electronic Resource
    Electronic Resource
    The role of kinetosome-associated organelles in the attachment of encysting secondary zoospores ofSaprolegnia ferax to substrates (1989)
    Springer
    Protoplasma 149 (1989), S. 163-174 
    Details
    ISSN: 1615-6102
    Keywords: Adhesion ; Carbohydrates ; Exocytosis ; K-bodies ; Lectins ; Saprolegnia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Electron and fluorescence microscopy were used to identify organelles involved in attachment of secondary zoospores ofSaprolegnia ferax as they were transformed into secondary cysts. When secondary zoospores were exposed to 1.0% peptone in the absence or presence of a substrate, they began to encyst. If substrates were present when encystment was induced, the groove surface of the secondary zoospores adhered to them. The first event in attachment was secretion of contents of the kinetosome-associated organelle (K-body), which was typically oriented with the tubule-filled cavity positioned toward the cell surface of the groove region in the zoospore. The tubules which contained carbohydrates became coarsely granular, the matrix became more fibrous, and the shell remained along the membrane concavity that was formed as the K-body fused with the plasma membrane. Five minutes later, a cyst coat appeared, and cysts were not readily dislodged from a substrate. The concavity was no longer found, presumably because it had evaginated; but a layered pad of adhesion material was between the cyst coat and substrate. The layers of the adhesion pad corresponded to the structure of the matrix of K-bodies. As with the tubules of the K-body, the coarsely granular portion at the edge of the pad stained for carbohydrates. Similarly, the lectins WGA and GS-II labeled with fluorescein stained the rim of the adhesion pad on cysts, indicating the presence of glycoconjugates containing N-acetylglucosamines. Because globular areas near the kinetosomes and groove of zoospores (where K-bodies were located) also bound WGA and GS-II, K-bodies contained the same carbohydrates as the adhesion pad. We conclude that K-bodies function in the attachment of encysting zoospores to substrates as the cell differentiates. The tubular portion of the K-body matrix contains carbohydrates which might assist in the adhesion process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01322988
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  • 46
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    Electronic Resource
    The cytoskeletal involvement in cellularization of theDrosophila melanogaster embryo (1989)
    Springer
    Protoplasma 150 (1989), S. 83-95 
    Details
    ISSN: 1615-6102
    Keywords: Drosophila melanogaster embryo ; Cellularization ; Cleavage furrow ; Ultrastructure ; Cytoskeleton ; Mitosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The distribution and arrangement of cytoskeletal components in the early embryo ofDrosophila melanogaster were examined by thin-section electron microscopy to elucidate their involvement in the formation of the cellular blastoderm, a process called cellularization. During the final nuclear division in the cortex of the syncytial blastoderm bundles of astral microtubules were closely associated with the surface plasma membrane along the midline where a new gutter was initiated. Thus the new gutter together with the pre-formed ones compartmentalized the embryo surface to reflect underlying individual daughter nuclei. Subsequently such gutters became deeper by further invagination of the plasma membrane between adjacent nuclei to form so-called cleavage furrows. Nuclei simultaneously elongated in the direction perpendicular to the embryo surface and numerous microtubules from the centrosomes ran longitudinally between the nucleus and the cleavage furrow. Microtubules often appeared to be in close association with the nuclear envelope and the cleavage furrow membrane. The plasma membrane at the advancing tip of the furrow was always undercoated with an electron-dense layer, which could be shown to be mainly composed of 5–6 nm microfilaments. These microfilaments were decorated with H-meromyosin to be identified as actin filaments. As cleavage proceeded, each nucleus with its perikaryon became demarcated by the furrow membrane, which then extended laterally to constrict the cytoplasmic connection between each newly forming cell and the central yolk region. The cytoplasmic strand thus formed possessed a prominent circular bundle of microfilaments which were also decorated with H-meromyosin and bidirectionally arranged, similar in structure to the contractile ring in cytokinesis. These observations strongly suggest that both microtubules and actin filaments play a crucial role in cellularization ofDrosophila embryos.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403663
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  • 47
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    Electronic Resource
    The effect of fuel oil on the ultrastructure of the chlorococcal algaScenedesmus armatus (1989)
    Springer
    Protoplasma 151 (1989), S. 47-56 
    Details
    ISSN: 1615-6102
    Keywords: Scenedesmus ; Fuel oil ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Characteristic changes in the ultrastructure of the green algaScenedesmus armatus, grown in batch culture in the presence of aqueous fuel-oil extract (AFOE) have been observed. The changes affected mainly chloroplasts and mitochondria. The regular arrangement of the thylakoid stacks became distorted and the whole chloroplast lobed. Plastoglobules were more numerous in the treated cells than in the controls, especially after long-term exposure to AFOE. The mitochondrial matrix cells exposed to AFOE were more electron-translucent. An increase in the number of small mitochondrial profiles was observed after prolonged treatment with AFOE. The number and size of osmophilic bodies increased markedly in the cytoplasm of the treated cells. The cytochemical reaction of these bodies with Sudan black B indicated their lipid composition. Plasmalemma invagination into the cytoplasm and vacuoles, cytoplasmic “layers”, and an increase in size of the vacuolar compartment were observed in cells exposed to AFOE for a long time. The possibility that detoxification, involving microbody activity, may have occurred inScenedesmus is suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403300
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  • 48
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    An unusual feature of developing protophloem sieve elements in roots ofTriticum aestivum L. (1989)
    Springer
    Protoplasma 152 (1989), S. 14-21 
    Details
    ISSN: 1615-6102
    Keywords: Differentiation ; Heterochronic lysis ; Polarity ; Root protophloem sieve elements ; Triticum aestivum ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Developing protophloem sieve elements in roots of wheat are arranged in single vertical files. In the last immature differentiating sieve element bearing ribosomes the proximal end of the cytoplasm displays a diluted appearance in contrast to the distal end where the cytoplasm exhibits a considerably increased electron density. Differences can also be observed in ribosome quantity, organelle ultrastructure and the time of initiation of cell component degradation, those at the proximal end disorganizing first, suggesting a nonsimultaneous disorganization of the cell components in the two areas. This phenomenon, termedheterochronic lysis, is presumably an expression of an existing polarity not detectable in younger stages, but it might also be the result of an asynchronous enzymatic activity.
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    URL: http://dx.doi.org/10.1007/BF01354235
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  • 49
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    Electronic Resource
    System-specific distribution of zinc in the chick brain (1989)
    Springer
    Cell & tissue research 258 (1989), S. 247-257 
    Details
    ISSN: 1432-0878
    Keywords: Zinc ; Timm method ; Ultrastructure ; Synapses ; Avian brain ; Domestic fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The brain of young domestic chicks was investigated using a Timm sulfide silver method. Serial Vibratome sections were analyzed under the light microscope, and the localization of zinc-positive structures in selected areas was determined at the ultrastructural level. Both strong and differential staining was visible in the avian telencephalon whereas most subtelencephalic structures showed a pale reaction. The highest staining intensity was found in the nonprimary sensory regions of the telencephalon such as the hyperstriatum dorsale, hyperstriatum ventrale, hippocampus, palaeostriatum augmentatum, lobus parolfactorius and caudal parts of neostriatum. There was an overall gradient of staining intensity in neostriatal areas from rostral to caudal with the heaviest zinc deposits in the caudal neostriatum. Primary sensory projection areas, such as the ectostriatum (visual), hyperstriatum intercalatum superius (visual), nucleus basalis (beak representation), the input layer L2 of the auditory field L and the somatosensory area rostral to field L were selectively left unstained. Fiber tracts throughout the brain were free of zinc deposits except for glial cells. In electron micrographs of stained regions, silver grains were localized in some presynaptic boutons of asymmetric synapses (Gray type I), within the cytoplasm of neuronal somata and sporadically in the nucleus. The possible involvement of zinc in synaptic transmission and other processes is discussed.
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    URL: http://dx.doi.org/10.1007/BF00239445
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  • 50
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    Ultrastructural changes in granule cell somata and mossy fibers of the rat hippocampus during picrotoxin-induced convulsions (1989)
    Springer
    Cell & tissue research 255 (1989), S. 261-267 
    Details
    ISSN: 1432-0878
    Keywords: Hippocampus ; Mossy fibers ; Picrotoxin ; Ultrastructure ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural changes in hippocampal granule cells, mossy fibers and mossy fiber boutons were examined following the administration of picrotoxin in adult rats. Generalized seizures occurred within 5–10 min after the intraperitoneal injection of picrotoxin. The electron-microscopic examination of hippocampal tissues from rats that had been perfused with fixative during the seizure revealed that the large dense-core vesicles increased in number and accumulated on the presynaptic membranes of mossy fiber boutons; some of these vesicles appeared to be fused with the membranes, and omega-shaped exocytotic profiles were frequently seen. Furthermore, greatly increased numbers of coated vesicles (60–90 nm in diameter) were observed on the maturing faces of Golgi fields of granule cells. Thus, our study not only indicates an increased incidence of exocytosis of large dense-core vesicles during picrotoxin-induced seizures, but also suggests that these vesicles are replaced in excess from the perikaryon of the granule cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224107
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  • 51
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    Distribution of peroxidase and iodination activity in the endostyles of Oikopleura albicans and Oikopleura longicauda (Appendicularia, Chordata) (1989)
    Springer
    Cell & tissue research 255 (1989), S. 505-510 
    Details
    ISSN: 1432-0878
    Keywords: Endostyle ; Peroxidase cytochemistry ; Autora diography ; Ultrastructure ; Oikopleura albicans, Oikopleura longicauda (Appendicularia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Oikopleura albicans and O. longicauda belong to the two subgenera Vexillaria and Coecaria, respectively. The morphology and ultrastructure of their endostyles were investigated with conventional microscopic procedures as well as with DAB cytochemistry and 125I autoradiography at both light- and electron-microscopic levels. As expected, the general morphology of these endostyles is similar to all hitherto examined endostyles. They possess a ventral portion consisting of alternating glandular and ciliated cell zones, probably serving food capture, and a dorsal region, the corridor. Autoradiographic grains were found mainly in the corridor lumen associated with the apical surface of the two central rows of corridor cells. The same cells also gave strong positive reactions for peroxidase, the iodinating enzyme. Peroxidase activity was found in the apical plasma membrane as well as in the nuclear envelope, rough endoplasmic reticulum, Golgi area and cytoplasmic vesicles. Definitive conclusions concerning an apical uptake and subsequent release into the body fluid of iodinated material could not be made from the present experiments. Our investigations indicate that the two central rows of corridor cells in both subgenera of oikopleurids constitute the protothyroid region, possibly homologous to the vertebrate thyroid gland.
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    URL: http://dx.doi.org/10.1007/BF00218785
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  • 52
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    Terminal processes of serotonin neurons in the caudal spinal cord of the molly, Poecilia latipinna, project to the leptomeninges and urophysis (1989)
    Springer
    Cell & tissue research 255 (1989), S. 619-625 
    Details
    ISSN: 1432-0878
    Keywords: Serotonin-containing cells ; Urophysis ; Spinal Cord ; Ultrastructure ; Leptomeninges ; Poecilia latipinna (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The caudal neurosecretory complex of poeciliids has previously been shown to be innervated by extranuclear and intrinsic serotonergic projections. In the present study, immunohistochemical techniques were used to characterize fibers originating from serotonin neurons intrinsic to the caudal spinal cord. Bipolar and multipolar neurons were oriented ventromedially, and contained numerous large granular vesicles. Three types of serotonergic fibers were distinguished based on their distribution and morphology. Intrinsic Type-A fibers branched into varicose segments near the ventrolateral surface of the spinal cord and contacted the basal lamina beneath the leptomeninges. Type-B fibers coursed longitudinally to enter the urophysis, where they diverged and terminated around fenestrated capillaries. Labelled vesicles in Type-A and Type-B terminals were the same size as those in labelled cells and in unlabelled neurosecretory terminals in the urophysis. Type-C small varicose fibers branched within the neuropil of the caudal neurosecretory complex. Serotonin may be secreted into the submeningeal cerebrospinal fluid, the urophysis, and the caudal vein by Type-A and Type-B fibers, whereas, Type-C fibers may be processes of serotonergic interneurons in the neuroendocrine nucleus. The possibility that urotensins I and II or arginine vasotocin were colocalized in the processes of the intrinsic serotonin neurons was investigated immunohistochemically. The negative results of these experiments suggest that serotonin-containing neurons may represent a neurochemically distinct subpopulation in the caudal neurosecretory complex.
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    URL: http://dx.doi.org/10.1007/BF00218799
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  • 53
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    Morphogenesis of rat cranial meninges (1989)
    Springer
    Cell & tissue research 257 (1989), S. 207-216 
    Details
    ISSN: 1432-0878
    Keywords: Morphogenesis ; Meninges ; Mesenchyme ; Ultrastructure ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The meninges of albino Wistar rat embryos, aged between the 11th embryonic day (ED) and birth, were sectioned using a specially constructed device. This technique permits optimal microanatomical preservation of all tissues covering the convexity of the brain: skin, muscle, cartilage or bone, and the meninges. At ED11, the zone situated between the epidermis and the brain is occupied by a mesenchymal network. At ED12, part of this delicate network develops as a dense outer cellular layer, while the remainder retains its reticular appearance, thus forming an inner layer (the future meningeal tissue). At ED13, the dura mater starts to differentiate. At ED14, the bony anlage of the skull can be identified, and along with the proceeding maturation of dura mater some fibrillar structures resembling skeletal muscle fibers appear in the developing arachnoid space. At ED15–17, a primitive interface zone — dura mater/ arachnoid — is formed, comprised by an outer electronlucent and an inner electron-dense layer marking the outer aspect of the arachnoidal space. At ED18–19, the innermost cellular row of the inner durai layer transforms into neurothelium, which is separated from the darker arachnoidal cells by an electron-dense band. The arachnoidal trabecular zone with the leptomeningeal cells is formed at ED19. By the end of the prenatal period (ED20–21), its innermost part organizes into an inner arachnoidal layer and an outer and inner pial layer. The results from this study indicate (i) that dura mater and leptomeninges develop from an embryonic network of connective tissue-forming cells, and (ii) that the formation of cerebrospinal fluid (CSF)-containing spaces accompanies the differentiation of the meningeal cellular layers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221652
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  • 54
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    Neural activity pattern is not necessary for the development of adult ultrastructure in katydid (Neoconocephalus robustus) singing muscles (1989)
    Springer
    Cell & tissue research 255 (1989), S. 641-644 
    Details
    ISSN: 1432-0878
    Keywords: Insect muscle ; Denervation ; Ultrastructure ; Development, ontogenetic ; Neoconocephalus robustus (Insecto)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The singing muscles of the katydid Neoconocephalus robustus develop adult ultrastructure late in the last nymphal instar and during the first few days of adult life. The ultrastructural changes during early adulthood were not affected by unilateral axotomy shortly after the adult molt. Both denervated and innervated muscles developed adult proportions of mitochondria, myofibril, and sarcoplasmic reticulum and transverse tubules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218802
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  • 55
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    Electronic Resource
    Effects of long-term hypergastrinaemia on the ultrastructure of enterochromaffin-like cells in the stomach of the rat, hamster and guinea pig (1989)
    Springer
    Cell & tissue research 256 (1989), S. 247-257 
    Details
    ISSN: 1432-0878
    Keywords: Enterochromaffin-like cells ; Ultrastructure ; Hypertrophy ; Hypergastrinaemia ; Gastrin infusion ; Omeprazole ; Rat (Sprague Dawley) ; Syrian hamster ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present report describes the ultrastructure of the enterochromaffin-like (ECL) cells in the stomach of the rat, hamster and guinea pig, and the ultrastructural consequences of long-term hypergastrinaemia evoked either by continuous infusion of synthetic human (Leu15)-gastrin-17 for 4 weeks (rats) or by daily treatment with large doses of the antisecretory agent omeprazole for 2–10 weeks (rats, hamsters and guinea pigs). As a result, the ECL cells increased greatly in size (maximal effect after 2 weeks of omeprazole treatment, no further gain in size after 4 or 10 weeks). Also the endoplasmic reticulum and Golgi area were enlarged. The most conspicuous feature of the ECL cells is the cytoplasmic vesicles, which are of varying size and either devoid of a dense core or with a small, often eccentrically located dense core. The vesicles probably represent the main storage site of the secretory products of the ECL cell. In addition, the cytoplasm contains granules, which differ from the vesicles in that they possess a more or less electron-dense core, surrounded by a narrow halo. The size of the vesicles ranged from small to very large, while the granules were uniformly small. Many vesicles were seen to lie very close together, some displaying an irregular outline (vacuole-like vesicles), at times giving the impression that they were undergoing fusion. The profile size (median value) of the vesicles was unaffected by gastrin infusion for 4 weeks. However, there was a tendency to a relative increase in the number of very small vesicles. In contrast, the vesicles became larger during the omeprazole treatment. Also, the number of vesicles that seemed to be engaged in fusion increased after omeprazole treatment but not after gastrin infusion. The observations support the view that ECL cells are influenced by gastrin. The effects of gastrin infusion and of omeprazole treatment on ECL cell ultrastructure were not completely identical. It cannot be excluded that the omeprazole-evoked achlorhydria evokes effects unrelated to those of hypergastrinaemia on the ECL cells, or that endogenous gastrins may evoke effects that are in some ways distinct from those of synthetic human (Leu15)-gastrin-17. Alternatively, the additional effects seen after long-term omeprazole treatment may reflect simply the duration of the hypergastrinaemic stimulus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218882
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  • 56
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    Electronic Resource
    Morphological changes in the junctional complex of cells in the arachnoid layer of the rat after cold injury (1989)
    Springer
    Cell & tissue research 256 (1989), S. 303-307 
    Details
    ISSN: 1432-0878
    Keywords: Arachnoid cells ; Tight and gap junctions ; Cold injury ; Ultrastructure ; Freeze-fracture technique ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The junctional complexes of cells in the outer arachnoid layer overlying the cerebral cortex of 2-week-old rats were examined with freeze-fracture electron microscopy up to 60 min after transcranial cold injury to the dorsal surface of the brain. Within 30 min after injury, areas of gap and tight junctions with morphological features characteristic of junction formation and/or junction disruption were found scattered among normal junctional complexes in some arachnoid cells. Within 60 min after injury, tight junctions with features typical of less leaky zonulae occludentes were present in all arachnoid cells examined. These morphological features include increases in the number of tight junctional strands and the number of strand-to-strand anatomoses. Gap junctions were interspersed among the tight junctional strands, and many were completely encircled by the strands. The increase in the number and complexity of the tight junctional strands in response to brain injury may be the morphological basis for the maintenance of the cerebrospinal fluid-blood dural barrier.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218887
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  • 57
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    Electronic Resource
    Smooth muscle fiber types and a novel pattern of thick filaments in the wing of the pteropod mollusc Clione limacina (1989)
    Springer
    Cell & tissue research 257 (1989), S. 405-414 
    Details
    ISSN: 1432-0878
    Keywords: Mollusc ; Ultrastructure ; Musculature ; Hydroskeleton ; Retraction reflex ; Clione limacina (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Wing (parapodial) retraction in the pteropod mollusc Clione limacina is a reflex triggered by tactile stimulation. Light and transmission electron microscopy revealed three groups of smooth muscles in the wing hemocoel that participate in retraction movements: transverse, longitudinal, and dorsoventral. Among these, two subtypes of muscle cells were identified. The first (type A) appears in all three groups and forms a well-organized lattice-like structure. The second (type B) is the major component of transverse muscles and runs in one direction only. Quantitative ultrastructural comparisons of dimensions, abundance, and organization of dense bodies, thick and thin filaments, membrane invaginations, sarcoplasmic reticulum, and mitochondria suggest that type A cells are able to contract and relax more quickly with less endurance whereas type B cells are capable of generating stronger contractions with more endurance and slower relaxation speed. Furthermore, type A cells have a unique pattern of thick filament organization, here referred to as pseudosarcomeres. The roles played by the different cell types in wing retraction are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00261843
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  • 58
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    Electronic Resource
    Ultrastructural changes induced by precocene II and 3,4-dihydroprecocene II in the corpora allata of Blattella germanica (1989)
    Springer
    Cell & tissue research 258 (1989), S. 91-99 
    Details
    ISSN: 1432-0878
    Keywords: Corpora allata ; Ultrastructure ; Precocenes ; Juvenile hormone ; Blattella germanica (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural studies on corpora allata (CA) from different stages during the first gonadotropic cycle of the cockroach Blattella germanica have shown well defined changes which have a correspondence with oocyte length, CA volume and juvenile hormone (JH) biosynthesis. The most significant variations concern the mitochondria and the endoplasmic reticulum. Topically applied precocene II (P II) at a dose of 200 ⧎g induced a transient arrest of CA function, although cytotoxic effects were occasionally observed. When CA were maintained in vitro with 10-3 M of P II, a relationship between the time of treatment (3, 6 or 9 h) and the intensity of the effects was apparent. The 9-h treatment led to an irreversible inhibition of JH production which parallels the severe damages observed in the CA (membrane lysis, nuclear pyknosis, vacuolization). Equivalent studies performed with the chroman derivative 3,4-dihydroprecocene II (DHP II) showed that it is less active than P II. Only treatments as severe as 12 h of incubation with a 10-3 M concentration elicited cytotoxic effects which could be due to radical species involved in the in situ oxidative bioactivation of DHP II. Thus, this compound could be regarded as a new type of pro-allatocidin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223148
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  • 59
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    Electronic Resource
    Structural features of the epididymis in a dasyurid marsupial (Antechinus stuartii) (1989)
    Springer
    Cell & tissue research 258 (1989), S. 203-210 
    Details
    ISSN: 1432-0878
    Keywords: Epididymis ; Histology ; Ultrastructure ; Antechinus stuartii (Marsupialia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ductus epididymidis of the marsupial mouse Antechinus stuartii was divided into caput, corpus, and caudal regions using several constant morphological landmarks. Tubule diameter and epithelial height increased gradually from caput to cauda. In contrast, the surface area of the lumen of the ductus epididymidis increased to a maximum in the distal caput region, but decreased markedly in the distal cauda in association with characteristic changes in lumen shape (from circular to slit-shaped) and epithelial height. Epithelial cells of the ductus epididymidis were generally similar in structure to those described in other mammalian species. Principal and basal cells were common throughout the epithelium. Clear and mitochondria-rich cells were also identified, but occurred less frequently. Regional variations in cell ultrastructure were observed only in principal cells. Numerous vesicular inclusions occurred in the apical cytoplasm of cells in caput segments, membrane-bounded, electron-dense bodies were common in distal corpus regions, and a brush border of microvilli characterized the luminal surface of principal cells in caudal segments. Sperm index increased in the proximal caput, declined to basal levels in the distal caput and proximal corpus, and then increased to a maximum in segment 9 of the distal corpus and remained at about this level throughout the cauda epididymidis. Nuclear rotation, loss of cytoplasmic droplets, and other sperm maturational changes were observed along the epididymis. Discarded cytoplasmic droplets collected in large masses interspersed between aggregates of spermatozoa throughout the distal regions of the duct. There was no evidence of phagocytosis by principal cells of cytoplasmic droplets. The epididymis of A. stuartii differs from that of other mammals. The unusual caudal region, which has little storage capacity for sperm, is an unusual adaptation in a species in which the male is known to be polygamous.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223158
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  • 60
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    Electronic Resource
    The effect of low- and high-density lipoprotein cholesterol on steroid hormone production and ACTH-induced differentiation of rat adrenocortical cells in primary culture (1989)
    Springer
    Cell & tissue research 256 (1989), S. 487-494 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Differentiation ; Tissue culture ; Steroids ; Ultrastructure ; Lipoproteins ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary We studied the effects of lipoprotein-derived cholesterol on the ACTH-induced differentiation of cultured fetal rat adrenocortical cells. For this purpose human plasma high-density lipoprotein3 (HDL3) or low-density lipoprotein (LDL) was added to culture media devoid of cholesterol, and thereafter the morphological changes in cells were monitored and the amounts of steroids synthesized were measured. It could be demonstrated that, ultrastructurally, upon ACTH-stimulation the adrenocortical cells differentiated into fasciculata-like cells even in the absence of lipoproteins in the culture medium. The addition of either HDL3 or LDL caused an increase in the number and size of cytoplasmic lipid droplets suggesting uptake and deposition of lipoprotein-derived cholesterol into the differentiating cells. The amount of steroids secreted from cells differentiating in media devoid of cholesterol was only half that observed in cells differentiating in serum-supplemented medium. Addition of either HDL3 or LDL increased the ACTH-stimulated steroid synthesis to the levels observed in serum-supplemented medium. This study demonstrates that both HDL3 and LDL are able to provide cholesterol for steroid synthesis accompanying the ACTH-induced differentiation of fetal rat adrenocortical cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225596
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  • 61
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    The three-dimensional structure of the zona pellucida in growing and atretic ovarian follicles of the mouse (1989)
    Springer
    Cell & tissue research 257 (1989), S. 247-253 
    Details
    ISSN: 1432-0878
    Keywords: Zona pellucida ; Ovarian follicles ; Atresia ; Ultrastructure ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present study provides further details on the fine-structural three-dimensional architecture of the zona pellucida (ZP) in growing and atretic follicles of mice by use of ruthenium red in combination with the detergents Triton X100 and saponin. These detergents were used for extraction of the “soluble” fraction of the zonal proteins in an attempt to expose the “structural” zonal glycoproteins, which in turn can be viewed as minute three-dimensional networks upon transmission- and scanning electron-microscopic examination. By use of these methods, the ZP of growing follicles appeared to be formed by interconnected filaments which also bind to globular structures building up a three-dimensional lattice. In contrast, the ZP of stage I as well as other (II and III) stages of atretic follicles showed a structure characterized by the presence of closely packed granules connected with short filaments to form a close-mesh reticulum. This structural change of the ZP, which in the present study is also associated with the disappearance of “gap junctions” within the granulosa and cumulus cell population, might represent one of the early events involved in the onset of atresia. These changes, most probably depending on an altered secretory activity of both oocytes and follicle cells, might lead to a degradation of the ZP network structure and to its subsequent increased density (condensation). All these morphodynamic events eventually contribute to a sequestration of the oocyte in the early stage of atresia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00261827
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  • 62
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    The effect of bromocriptine on the intermediate lobe of the rat pituitary: an electron-microscopic, morphometric study (1989)
    Springer
    Cell & tissue research 255 (1989), S. 405-410 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland, pars intermedia ; Bromocriptine ; Secretory granules ; Golgi apparatus ; Ultrastructure ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphological effect of chronic synthetic and secretory inhibition of the intermediate lobe of the rat pituitary induced by bromocriptine treatment was studied using morphometric techniques in combination with electron microscopy. On the basis of granule diameters, a heterogeneous cell population was shown in the normal intermediate lobe. Bromocriptine treatment did not induce any change in the volume fraction, number or location of electron-dense secretory granules. Instead, there was a shift toward a more homogeneous cell population containing smaller granules, the mean granule volume being reduced by ∼30%. The volume fraction of electron-lucent granules or vacuoles was markedly reduced, indicating a functional significance of these organelles. The volume of the Golgi apparatus was not significantly altered, but the number of condensing granules within the Golgi area was reduced. The volume of the intermediate lobe was decreased, apparently due to a decrease in the mean cell volume.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224124
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  • 63
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    Zur Kenntnis neuer Oxochromate: SrCr10O15 und BaCr10O15 mit zweiwertigem Chrom: MCr22+Cr83+O15 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 572 (1989), S. 89-94 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: About New Oxochromates: SrCr10O15 and BaCr10O15 Containing Divalent Chromium: MCr22+Cr83+O15High temperature reaction using reducing atmosphere lead to the new compounds (I) SrCr10O15 and (II) BaCr10O15. Single crystal X-ray investigations show orthorhombic symmetry: space group D2h18-Ccmb; I: a = 10.059; b = 11.406; c = 9.224 Å; II: a = 10.126; b = 11.491; c = 9.392 Å; Z = 4. Cr2+/Cr3+ are octahedral coordinated by O2-. Inside a CrO6-octahedral network are cavities comparable with those of some polyacids filled by Sr2+ or Ba2+ ions.
    Notes: Mit Hochtemperaturreaktionen in reduzierender Atmosphäre gelang die Darstellung der gemischtvalenten Oxochromate(I) SrCr10O15 und (II) BaCr10O15. Diese kristallisieren orthorhombisch, Raumgruppe D2h18-Ccmb mit (I): a = 10,059; b = 11,406; c = 9,224 Å und II: a = 10,126; b = 11,491; c = 9,392 Å; Z = 4. Cr2+/Cr3+ bilden mit O2- ein Oktaedergerüst, je 12 Oktaeder bauen wie bei Polysäuren für Sr2+ bzw. Ba2+ einen großvolumigen Hohlraum auf.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895720110
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  • 64
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    BaNi2In4Sc4O15 mit BaV10O15-Struktur, aber mit geordneter Metallverteilung (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 572 (1989), S. 109-114 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: BaNi2In4Sc4O15 with BaV10O15-Structure, but Ordered Metal DistributionSingle crystal X-ray investigations of BaNi2In4Sc4O15 [space group D2h18-Cmca, a = 12.146; b = 10.880; c = 9.834 Å; Z = 4] show a statistical distribution of Ni2+ and Sc3+ of one of the possible point positions. The other oxygen octahedra are occupied by In3+ and Sc3+. This is the difference to compounds of the formula BaM10O15 (M = V, Cr, Ni/Cr) with total statistical metal distribution.
    Notes: Einkristalluntersuchungen an BaNi2In4Sc4O15 [Raumgruppe D2h18-Cmca. a = 12,146; b = 10,880; c = 9,834 Å; Z = 4] zeigen, daß Ni2+ nur mit Sc3+ eine der oktaedrisch koordinierten Metallpunktlagen statistisch besetzt. Alle anderen Polyeder sind frei von Ni2+, womit diese Verbindung sich von den Oxiden BaM10O15 (M = V, Cr, Ni/Cr) mit total statistischer Metallverteilung unterscheidet.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895720113
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  • 65
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    Ein Beitrag zur Kristallchemie der Oxotantalate. V. Geordnete und ungeordnete Metallverteilung in MnZn2Ta2O8 und Mn0,33Zn0,67Ta2O6 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 572 (1989), S. 102-108 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Contribution on the Crystal Chemistry of Oxotantalates. V. Ordered and Disordered Metal Distributions in MnZn2Ta2O8 and Mn0.33Zn0.67Ta2O6The compounds (I) MnZn2Ta2O8 and (II) Mn0.33Zn0.67Ta2O6 were prepared by solid state reactions. Single crystal X-ray investigations show (I): a = 19.286; b = 5.922; c = 5.228 Å; β = 90.3°; Z = 4; space group C2h6-C2/c; (II): a = 4.730; b = 17.154; c = 5.093 Å; Z = 4; space group D2h14-Pbcn. I belongs to the Zn3Nb2O8-type with ordered Mn2+, Zn2+ distribution. II crystalizes like tri-α-PbO2 (for example ZnTa2O6) but in respect to the metal distribution it belongs to the disordered α-PbO2-type.
    Notes: Mit Hilfe von Festkörperreaktionen wurden (I) MnZn2Ta2O8 und (II) Mn0,33Zn0,67Ta2O6 einkristallin dargestellt. [(I): a = 19,286; b = 5,922; c = 5,228 Å; β = 90,3°; Z = 4; Raumgruppe C2h6-C2/c; (II): a = 4,730; b = 17,154; c = 5,093 Å; Z = 4; Raumgruppe D2h14-Pbcn] I gehört zum Zn3Nb2O8-Typ mit geordneter Mn2+,Zn2+-Verteilung. Die Verwandtschaft zum Columbit wird aufgezeigt. II kristallisiert wie tri-α-PbO2 (z. B. ZnTa2O6), allerdings mit einer ungeordneten Metallverteilung, womit sie kristallchemisch zur α-PbO2-Struktur gehört.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895720112
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    Über Chalkogenolate. 192. S-Bis(trimethylsilyl)aminoester von Dithiocarbamidsäuren 1. Darstellung und Eigenschaften (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 572 (1989), S. 126-134 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Chalcogenolates. 192. S-Bis(trimethylsilyl)amino Esters of Dithiocarbamic Acids. 1. Synthesis and PropertiesThe title compounds RR′N—CS—S—N[Si(CH3)3]2, where R = R′ = CH3, C2H5, CH(CH3)2, CH2—C6H5, and with R = CH3 and R′ = C6H5 have been prepared by three procedures: by splitting the S—S bond of disulfanes [RR′N—CS—]2S2 with Na[N(Si(CH3)3)2] and with [(CH3)3Si]2N—MgBr as well as by reaction of Na[S2C—NRR′] with BrN[Si(CH3)3]2. The yields are compared.Physical and chemical properties are described, mass spectra are given.
    Notes: Die Titelverbindungen RR′N—CS—S—N[Si(CH3)3]2 mit R = R′ = CH3, C2H5, CH(CH3)2 und CH2—C6H5 sowie mit R = CH3 und R′ = C6H5 wurden nach drei Verfahren hergestellt: durch Spaltung der S—S-Bindung von Disulfanen [RR′N—CS—]2S2 mit Na[N(Si(CH3)3)2] und mit [(CH3)3Si]2N—MgBr sowie durch Reaktion von Na[S2C—NRR′] mit BrN[Si(CH3)3]2. Die Ausbeuten werden verglichen.Physikalische und chemische Eigenschaften sowie Massenspektren werden mitgeteilt.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895720115
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  • 67
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    Über das Oxoindat Ba4In2O7 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 12-18 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Oxoindate Ba4In2O7Ba4In2O7 was prepared for the first time by solid state reaction and investigated by X-ray methods. (Space group D4h17-14/mmm, a = 4.175; c = 29.483 Å; Z = 2). It shows a close crystal chemical relationship to Ba3In2O6 and La2SrCu2O6. One of the oxygen point positions is occupied only by a half. This fact alleviates the understanding of the layer structure of Ba4In2O7. The compound is compared with Sr4Tl2O7 and a further discussion in respect to Ba5In2O8 shows the probable identity of Ba5In2O8 with Ba4In2O7.
    Notes: Ba4In2O7 wurde erstmals dargestellt und an Einkristallen mit Röntgenbeugungsmethoden untersucht. (Raumgruppe D4h17-14/mmm, a = 4,175; c = 29,483 Å; Z = 2). Es liegt eine enge kristallchemische Verwandtschaft zu Ba3In2O6 und z. B. La2SrCu2O6 vor. Eine der Sauerstoffpunktlagen ist nur zur Hälfte besetzt; das macht den Schichtstrukturaufbau verständlich. Ba4In2O7 wird mit Sr4Tl2O7 verglichen. Eine Diskussion zeigt, daß Ba5In2O8 vermutlich mit Ba4In2O7 identisch ist.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730103
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  • 68
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    Über ein Oxotantalat mit teilgeordneter Korundstruktur: Mn0,6Mg3,4Ta2O9 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 19-23 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: About an Oxotantalate with Partly Ordered Corundum-Structure: Mn0.6Mg3.4Ta2O9In the system of mixed crystals of the composition Mn4-xMgxTa2O9 single crystals with x = 3.4 were examined by X-ray methods (space group D43d-P3c1; a = 5.2141; c = 14.178 Å; Z = 2). The point positions of the divalent metals are occupied in an ordered manner. Order and disorder are discussed in respect to Mn2Zn2Nb2O9, Mn3ZnNb2O9, and oxotantalates (MM′)4Ta2O9 [M, M′ = Zn, Ni, Mg].
    Notes: Im System Mn4-xMgxTa2O6 wurden Einkristalle für x = 3,4 mit Röntgenbeugung untersucht (Raumgruppe D43d-P3c1, a = 5,2141; c = 14,178 Å, Z = 2). Mn2+ und Mg2+ besetzen die entsprechenden Metallpunktlagen partiell geordnet. Der Grad der Ordnung wird im Vergleich zu Mn2Zn2Nb2O9, Mn3ZnNb2O9 und den Oxotantalaten (MM′)4Ta2O9 [M, M′ = Zn, Ni, Mg] diskutiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730104
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  • 69
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    Ligandenaustausch an Halogenonitrosyltechnetat(II)-Verbindungen. Eine EPR-Untersuchung (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 63-74 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ligand Exchange on Halogenonitrosyl-technetate(II) Compounds. An EPR StudyHalide ligand exchange reactions on the 4t52g low-spin halogenonitrosyltechnetate(II) complexes (n-Bu4N)2[Tc(NO)Cl5], (n-Bu4N)[Tc(NO)Br4], and (n-Bu4N)[Tc(NO)I4] have been analyzed by EPR. The EPR parameters go, aTco, ‖ and A‖Tc measured for the different mixed-ligand complexes of the type [Tc(NO)X4-pYpZ]2- (X, Y-Cl, Br, I; Z - axially coordinated solvent molecule or halide) are shown to be clearly correlated to the composition of the coordination sphere and can be used to characterize the mixed-ligand complexes unambiguously.
    Notes: Es wird über EPR-Untersuchungen zum Halogen-Ligandenaustausch an den 4t52g-„low-spin“-Halogenonitrosyltechnetat(II)-Komplexen (n-Bu4N)2[Tc(NO)Cl5], (n-Bu4N)[Tc(NO)Br4] und (n-Bu4N)[Tc(NO)I4] berichtet. Die Spektrenparameter go, aTco,g‖ und A‖Tc der verschiedenen beobachteten Gemischtligandkomplexe des Typs [Tc(NO)X4-pYpZ]2- (X, Y-Cl, Br, I; Z - axial koordiniertes Solventmolekül bzw. Halogenid) zeigen eine definierte Abhängigkeit von der Zusammensetzung der Koordinationssphäre und erweisen sich für die eindeutige Charakterisierung von Gemischt-Ligandenkomplexen als geeignet.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895730107
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  • 70
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    Über Chalkogenolate. 193. S-Bis(trimethylsilyl)aminoester von Dithiocarbamidsäuren 2. Spektroskopische Charakterisierung (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 75-88 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Chalcogenolates. 193. S-Bis(trimethylsilyl)amino Esters of Dithiocarbamic Acids. 2. Spectroscopic CharacterizationElectron absorption, infrared, and nuclear magnetic resonance spectra (1H, 13C, 29Si, 15N) of the title compounds RR′N—CS—S—N[Si(CH3)3]2 with R = R′ = CH3, C2H5, CH(CH3)2, CH2—C6H5 as well as with R = CH3 and R′ = C6H5 are communicated and discussed.Coupling constants have been determined (data see „Inhaltsübersicht“).For the compound with R = R′ = CH3 the free activation energy of the rotation barrier around the N—CS bond is ΔG* = 58 kJ/mol at -2°C (coalescence temperature).
    Notes: Elektronenabsorptions-, Infrarot- und Kernresonanzspektren (1H, 13C, 29Si, 15N) der Titelverbindungen RR′N—CS—S—N[Si(CH3)3]2 mit R = R′ = CH3, C2H5, CH(CH3)2, CH2—C6H5 sowie mit R = CH3 und R′ = C6H5 werden mitgeteilt und diskutiert.Folgende Kopplungskonstanten wurden ermittelt (R = R′ = CH3):\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{l} ^{\rm 1} {\rm J}\left({{}^{\rm 1}{\rm H} - {}^{12}{\rm C}} \right) = 119{\rm Hz},{}^2{\rm J}({}^1{\rm H} - {}^{29}{\rm Si} = 6,5{\rm Hz}, \\ ^{\rm 1} {\rm J}\left({{}^{{\rm 13}}{\rm C} - {}^{12}{\rm Si}} \right) = 57,7{\rm Hz},{}^2{\rm J}({}^{13}{\rm C} - {}^{15}{\rm N} = 1,97{\rm Hz}, \\ ^{\rm 1} {\rm J}\left({{}^{{\rm 29}}{\rm Si} - {}^{15}{\rm N}} \right) = 8,97{\rm Hz},{}^3{\rm J}({}^{15}{\rm N} - {}^1{\rm H)} \approx 0,5{\rm Hz}{\rm .} \\ \end{array} $$\end{document}Für die Verbindung mit R = R′ = CH3 beträgt die freie Aktivierungsenergie der Rotationsbarriere um die N—CS-Bindung ΔG* = 58 kJ/mol bei der Koaleszenztemperatur (-2°C).
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895730108
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  • 71
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    „LaTa5O14“, ein Derivat der tetragonalen Wolframbronzen Präparation und Struktur (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 107-118 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: „LaTa5O14“, a Derivative of the Tetragonal Tungsten Bronzes. Preparation and Structure„LaTa5O14“ single crystals were synthesized for the first time by heating mixtures La2O3/Ta2O5 (1:5) at temperatures of T = 1 685°C in air. „LaTa5O14“ crystallizes in the orthorhombic space group Cmmm with a = 16.977(1) Å, b = 17.594(1) Å and c = 3.8480(4) Å. The structure was refined to give R = 6.36% and Rw = 3.27%. The Ta atoms are partly surrounded by O octahedrally, partly pentagonal-bipyramidal. The unit cell is built up by layers of composition [Ta22O62]14- connected along the [001] direction with holes filled up totally or partly with La. The relationship to the tetragonal tungsten bronzes will be discussed.
    Notes: Im System La2O3/Ta2O5 gelang erstmals die Darstellung von gelben „LaTa5O14“-Einkristallen durch Tempern der Gemenge La2O3/Ta2O5 (1:5) bei T = 1 685°C an Luft. „LaTa5O14“ kristallisiert orthorhombisch in der Raumgruppe Cmmm mit den Gitterkonstanten a = 16,977(1) Å, b = 17,594(1) Å und c = 3,8480(4) Å. Die Struktur wurde bis R = 6,36% bzw. Rw = 3,27% verfeinert. Ta(1), Ta(3) und Ta(4) sind oktaedrisch, Ta(2) ist pentagonal-bipyramidal von O umgeben. Schichten aus diesen Polyedern sind über O-Teilchen entlang [001] miteinander eckenverknüpft. Vom Ta-O-Netzwerk der Zusammensetzung [Ta22O62]14- gebildete Lücken sind ganz oder teilweise mit La-Teilchen gefüllt; die Verbindung besitzt deshalb nur annähernd die Zusammensetzung LaTa5O14. Eine Verwandtschaft zu den tetragonalen Wolframbronzen ist erkennbar.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895730111
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    Elektronenmikroskopische Untersuchung in Hochauflösung an La3TaO5(OH)Cl3 und Pr3TaO4Cl6 - Vergleich mit der rechnerischen Simulation (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 119-127 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: High Resolution Electron Microscopy Investigation of La3TaO5(OH)Cl3 and Pr3TaO4Cl6 - A Comparison with Calculated ImagesThe phases La3TaO5(OH)Cl3 and Pr3TaO4Cl6 prepared by chemical transport have been investigated by high resolution electron microscopy. The micrographs taken agree well with simulated images. In spite of the close relationship of both structures the simulated images are not as similar as expected. The unoccupied channels at the corners of the cell can be seen distinctly. According to the resolution of our electron microscope La3TaO5(OH)Cl3 lattice constants of which are too small does not show any further detail, whereas the sites of the heavy atoms of Pr3TaO4Cl6 can be recognized at a suitable value of defocus.
    Notes: Kristalline Proben von La3TaO5(OH)Cl3 und der neuen Verbindung Pr3TaO4Cl6 konnten durch eine chemische Transportreaktion erhalten werden. Bei elektronenmikroskopischen Untersuchungen in Hochauflösung zeigten die Aufnahmen eine gute Übereinstimmung mit Bildern, die mit einem Kontrastprogramm simuliert worden waren. Wie eine Gegenüberstellung von zwei simulierten Defokusserien ergab, ist die enge strukturelle Verwandtschaft der beiden Oxidchloride hier nicht unmittelbar wiederzufinden. Man erkennt bei beiden Verbindungen die an den Eckpunkten der Zelle gelegenen unbesetzten Kanäle, die sich deutlich vom übrigen Kontrastmuster abheben. Bei La3TaO5(OH)Cl3, der Verbindung mit den kürzeren Gitterkonstanten, reichte das Auflösungsvermögen unseres Mikroskops für weitere Details im Innern der Elementarzelle nicht aus, während bei Pr3TaO4Cl6 die Schweratomlagen bei geeigneten Defokusbedingungen noch zu erkennen sind.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895730112
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  • 73
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    Neues über Oxotellurate(VI) der Alkalimetalle Zur Existenz und Konstitution von Li6TeO6 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 133-142 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Oxotellurates(VI) of the Alkali Metals. Existence and Constitution of Li6TeO6For the first time Li6TeO6 is prepared as transparent, colourless single crystals, and the structure has been determined [four-circle diffractometer data, Siemens AED2, MoKα, 371 out of 371 IO(hkl), R = RW = 0.7%, R3, a = 791.99(6) pm, c = 696.44(7) pm, Z = 3].The structure refinement shows that Li6TeO6 is a variant of the NaCl-Typ. Nevertheless there is a relationship with α-Li6UO6 [2]. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, the latter derived from Mean Effective Fictive Ionic Radii, MEFIR, are calculated and discussed.
    Notes: Erstmals wurden klar durchscheinende, farblose Einkristalle von Li6TeO6 dargestellt und strukturell untersucht. [Vierkreisdiffraktometerdaten, Siemens AED2, MoKα-Strahlung, 371 von 371 IO(hkl), R = RW = 0,7%, R3, a = 791,99(6) pm, c = 696,44(7) pm, Z = 3].Die Strukturbestimmung zeigt, daß Li6TeO6 eine Variante des NaCl-Typs ist. Dennoch besteht Verwandtschaft mit α-Li6UO6 [2]. Der Madelunganteil der Gitterenergie, MAPLE, sowie Effektive Koordinationszahlen, ECoN, diese über Mittlere Effektive Ionenradien, MEFIR, werden berechnet und diskutiert.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730114
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    Zwei neue Ordnungs-Varianten des NaCl-Typs: Li4MoO5 und Li4WO5 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 157-169 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Two New Variants of the NaCl Type of Structure: On Li4MoO5 and Li4WO5For the first time in form of colourless, transparent single crystals of Li4MoO5 [annealed mixtures of Li2O and MoO3, Li:Mo = 4.2:1, Ni-cylinder, 950°C, 28 d] as well as Li4WO5 [annealed mixtures of Li2O and WO3, Li:W = 4.4:1, Au-tube, 950°C, 28 d, slowly cooling] have been prepared. Single crystal data show isotypic oxides of the Li4TeO5-type, a deformed variant of the NaCl-type of structure [Li4MoO5: 1379 IO(hkl), four-circle-diffraktometer Philips PW 1100, ω--2Θ scan, AgKα, R = 8.7% and RW = 8.3%, space group P1 with a = 511.9(1), b = 772.7(2), c = 506.4(1) pm, α = 101.70(1)°, β = 101.48(1)°, γ = 108.58(2)°, Z = 2 and Li4WO5: 1027 IO(hkl), Philips PW 1100, ω-2Θ scan, MoKα, R = 4.0% und RW = 3.7%, space group P1 with a = 510.94(5), b = 771.59(7), c = 506.09(4) pm, α = 101.804(8)°, β = 101.78(1)°, γ = 108.770(9)°, Z = 2]. The structural relations are deduced from Schlegel Diagrams. The Madelung Part of Lattice Energie, MAPLE, and Effective Coordination Numbers, ECON, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.
    Notes: Erstmals wurde in Form farbloser, transparenter Einkristalle Li4MoO5 [aus Gemengen von Li2O und MoO3. Li:Mo = 4,2:1, Ni-Bömbchen, 950°C, 28 d] sowie Li4WO5 [aus Gemengen von Li2O und WO3, Li:W = 4,4:1, Au-Rohr, 900°C, 30 d] dargestellt. Nach Einkristalldaten liegt bei den isotypen Oxiden vom Li4TeO5-Typ eine Ordnungsvariante des NaCl-Typs [Li4MoO5: 1379 IO(hkl), Vierkreisdiffraktometer Philips PW 1100, ω-2Θ scan, AgKα, R = 8,7% und RW = 8,3%, Raumgruppe P1 mit a = 511,9(1), b = 772,7(2), c = 506,4(1) pm, α = 101,70(1)°, β = 101,48(1)°, γ = 108,58(2)°, Z = 2 bzw. Li4WO5: 1027 IO(hkl), Philips PW 1100, ω-2Θ scan, MoKα, R = 4,0% und RW = 3,7%, Raumgruppe P1 mit a = 510,94(5), b = 771,59(7), c = 506,09(4) pm, α = 101,804(8)°, β = 101,78(1)°, γ = 108,770(9)°, Z = 2] vor.Die strukturellen Zusammenhänge werden aus den Schlegel-Diagrammen abgeleitet. Der Madelunganteil der Gitterenergie, MAPLE, sowie Effektive Koordinationszahlen, ECON, diese über Mittlere Fiktive Ionenradien, MEFIR, berechnet, werden mitgeteilt und diskutiert.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730116
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    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
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730118
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    Darstellung und Eigenschaften von 1,2,3-Thiazaborolen, 3-Sulfoimido- und 3-Pseudohalogeno-1,2,3-dithiaborolen (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 199-207 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Properties of 1,2,3-Thiazaboroles, 3-Sulfoimido- and 3-Pseudohalido-1,2,3-dithiaborolesThe reactions of 3,4,5-trimethyl- and 4,5-diethyl-3-methyl-1,2,3-dithiaborole with di-t.-butylsulfurdiimide leads to the 1,2,3-thiazaboroles 2. 3-Bromo-1,2,3-dithiaboroles react with trimethylsilyl-N-sulfinylamine, -isocyanate, and -cyanide by formation of 3-sulfoimido- (3), 3-isocyanato- (4), and 3-cyano- (5) -1,2,3-dithiaboroles. 3-Isothiocyanato-1,2,3-dithiaboroles (6) are formed by addition of elemental sulfur to 5. 1H-, 11B-, 13C-, 14N-, 15N-NMR-, mass-, and IR spectra are reported and discussed.
    Notes: Die Reaktionen von 3,4,5-Trimethyl- und 4,5-Diethyl-3-methyl-1,2,3-dithiaborol mit Di-t.-butylschwefeldiimid führen zu den 1,2,3-Thiazaborolen 2. 3-Brom-1,2,3-dithiaborole reagieren mit Trimethylsilyl-N-sulfinylamin, -isocyanat und -cyanid unter Bildung von 3-Sulfoimido- (3), 3-Isocyanato- (4) und 3-Cyano- (5) -1,2,3-dithiaborolen. 3-Isothiocyanato-1,2,3-dithiaborole (6) werden gebildet bei Addition elementaren Schwefels an 5. 1H-, 11B-, 13C-, 14N-, 15N-NMR, Massen- und IR-Spektren werden mitgeteilt und diskutiert.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/zaac.19895730120
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    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
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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).
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895730122
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    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
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730124
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    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
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730126
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  • 80
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    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
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730127
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    Ni5HfB2O10 mit geordneter MetallverteilungProfessor Reginald Gruehn zum 60. Geburtstage am 6. Oktober 1989 gewidmet (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 26-30 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ni5HfB2O10 with Ordered Metal DistributionNi5HfB2O10 was prepared for the first time and investigated by X-ray methods. It crystallizes with orthorhombic symmetry, space group D2h16 - Pnma, a = 9.328; b = 6.120; c = 12.334 Å; Z = 4. In opposition to the Ni5TiB2O10-type all metal point positions are strongly ordered. The authors are in doubt about the partly statistic metal distribution within Ni5M4+B2O10 (M4+ = Ti, Zr, Ge).
    Notes: Ni5HfB2O10 wurde erstmals dargestellt und an Einkristallen untersucht. Ni5HfB2O10 kristallisiert orthorhombisch, Raumgruppe D2h16 - Pnma, a = 9,328; b = 6,120; c = 12,334 Å, Z = 4. Im Gegensatz zum Ni5TiB2O10-Typ weist NiHfB2O10 eine total geordnete Metallverteilung auf. Die partiell statistische Verteilung von Ni2+ mit M4+ (M4+ = Ti, Zr, Ge) wird in Frage gestellt.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895750105
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  • 82
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    27Al-NMR-Untersuchungen an Alkalifluoroaluminaten (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 17-25 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 27Al NMR Studies on Alkali FluoroaluminatesThe 27Al NMR spectra of the alkali fluoroaluminates sensitively reflect the kind of condensation of the AlF6 octahedra. Whereas the chemical shift of the octahedral Al is shown to be rather independent on structural details, clear differences in the electric field gradients of isolated and condensed AlF6 octahedra were found. In contrast to the isolated octahedra which show only weak effects of quadrupole interaction, both for chains and layers of AlF6 octahedra axial EFG tensors result with quadrupolar coupling constants of between 10 and 13 MHz; for the threefold chains in CsAlF4 only a value of 7.5 MHz is obtained.
    Notes: Die 27Al-NMR-Spektren der Alkalifluoroaluminate spiegeln in empfindlicher Weise die Verknüpfung der AlF6-Oktaeder wider. Während sich die chemische Verschiebung für das oktaedrisch koordinierte Aluminium als nahezu unbeeinflußt von strukturellen Details erweist, ergeben sich deutliche Unterschiede in den elektrischen Feldgradienten (EFG) zwischen isolierten und verknüpften AlF6-Oktaedern. Im Gegensatz zu den isolierten Oktaedern, bei denen Quadrupolwechselwirkungseffekte nur eine untergeordnete Rolle spielen, ergeben sich sowohl für Ketten als auch schichtförmige Verknüpfung der AlF6-Oktaeder axiale EFG-Tensoren mit Quadrupolkopplungskonstanten zwischen 10 und 13 MHz, bei Verknüpfung als Dreierstrangkette im CsAlF4 lediglich ein Wert von 7,5 MHz.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895750104
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  • 83
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    Ein Beitrag zur Kristallchemie der Erdalkalimetall-Oxochromate(V): Sr3(CrO4)2 und Sr18Ca3Cr14O56 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 572 (1989), S. 95-101 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Contribution about the Crystal Chemistry of Alkaline Earth Oxochromates(V): Sr3(CrO4)2 and Sr18Ca3Cr14O56The crystal structure of (I) Sr3Cr3(CrO4)2 was examined by X-ray single crystal technique. It belongs to the Ba3(PO4)2-type, space group 3d5-R3m, a = 5.562; c = 20.221 Å; Z = 3. The replacement of Sr2+ leads to a compound of the formula (II) Sr18Ca3Cr14O56, space group 3v6-R3c, a = 11.004; c = 39.256 Å; Z = 3. The Sr2+ and Ca2+ ions occupy the alkaline earth positions in an ordered manner. So the formulation Sr2.57Ca0.43(CrO4)2 should be avoided although it belongs to the β-Ca3(PO4)2 = Ca3(CrO4)2-type. The crystal chemistry of (I) and (II) is discussed.
    Notes: Die Kristallstruktur von (I) Sr3(CrO4)2 wurde an Einkristallen exakt untersucht. Sie gehört zum Ba3(PO4)2-Typ, Raumgruppe D3d5-R3m, a = 5,562; c = 20,221 Å; Z = 3. Der Ersatz von Sr2+ gegen Ca2+ führt zur Verbindung (II) Sr18Ca3Cr14O56, Raumgruppe C3v6-R3c, a = 11,004; c = 39,256 Å; Z = 3. Es wird gezeigt, daß Sr2+ und Ca2+ die Erdalkalimetall-Positionen im β-Ca3(PO4)2-Typ geordnet besetzen, womit die Schreibweise Sr2,57Ca0,43(CrO4)2 nicht verwendet werden sollte, obwohl dieser Stoff zum β-Ca3(PO4)2 = Ca3(CrO4)-Typ gehört. Die Kristallchemie von (I) und (II) wird diskutiert.
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    URL: http://dx.doi.org/10.1002/zaac.19895720111
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  • 84
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    Molekül- und Kristallstruktur des 1,4-Bis[tris(tetrahydrofuran)lithium]-octaphenyltetrasilans (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 572 (1989), S. 63-74 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Molecular and Crystal Structure of 1,4-Bis[tris(tetrahydrofuran)lithium]-octaphenyltetrasilane1,4-Dilithium-octaphenyltetrasilane prepared from octaphenyl-cyclo-tetrasilane and lithium in tetrahydrofuran (THF) [4], can be isolated from tetrahydrofuran/n-pentane as an adduct with six molecules of tetrahydrofuran per formula unit. The orange-red compound crystallizes in the triclinic space group P1 {a = 1159.6(3); b = 1268.4(2); c = 1367.8(3) pm; α = 92,23(2)° β = 113.79(2)° γ = 111.62(2)° at -5 ± 3°C; Z = 1}. An x-ray structure determination (Rw = 0.046) shows the existence of a centrosymmetric molecule with an extended planar Li—Si4—Li unit; either lithium atom is bound to silicon and to the oxygen atoms of three molecules of tetrahydrofuran. Characteristic bond lengths and angles are: Li—Si 271; Si—Si 241 and 243; Si—C 190 to 192 pm; Li—Si—Si 126°; Si—Si—Si 127°. 29Si and 7Li n.m.r. measurements at low temperatures indicate the presence of three different adducts.
    Notes: Das aus Octaphenyl-cyclo-tetrasilan und Lithium in Tetrahydrofuran (THF) dargestellte, orangerote 1,4-Dilithium-octaphenyltetrasilan [4] kristallisiert aus Tetrahydrofuran/n-Pentan als Addukt mit sechs Molekülen Tetrahydrofuran triklin in der Raumgruppe P1. Die Verbindung weist folgende, bei -5 ± 3°C bestimmte Parameter der Elementarzelle auf: a = 1159,6(3); b = 1268,4(2); c = 1367,8(3) pm; α = 92,23(2)°; β = 113,79(2)° γ = 111,62(2)°; Z = 1. Nach den Ergebnissen einer Röntgenstrukturanalyse (Rw = 0,046) liegt ein zentrosymmetrisches Molekül mit gestrecktem, planarem Li—Si4—Li-Gerüst vor; jedes Lithium ist an Silicium und die Sauerstoffatome aus drei Tetrahydrofuran-Molekülen gebunden. Charakteristische Bindungslängen und -winkel sind: Li—Si 271; Si—Si 241 und 243; Si—C 190 bis 192 pm; Li—Si—Si 126°; Si—Si—Si 127°. 29Si- und 7Li-Kernresonanz-Messungen bei tiefen Temperaturen ergeben in Lösung drei unterschiedliche Addukte.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895720108
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  • 85
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    Metallderivate von Molekülverbindungen. II. Darstellung und Struktur des β-Kaliumsilanids (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 572 (1989), S. 75-88 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metal Derivatives of Molecular Compounds. II. Preparation and Structure of β-Potassium SilanideAt -5°C potassium silanide crystallizes from 1,2-dimethoxyethane/n-pentane in a to date unknown low temperature modification {β-form: orthorhombic, Pnma, Z = 4; a = 880.0(2), b = 541.6(1), c = 682.3(1) pm at -110 ± 3°C}. An x-ray structure determination shows the compound to be built up from isolated potassium cations and pyramidal silanide anions without perceptible disorder. Seven counterions make up the coordination sphere of either particle (K⃛Si 356 to 386 pm), two anion-anion contacts (Si⃛Si 355 pm) are observed in addition. The packing of ions represents a defect variant of the barite type, but there are also relationships to the high temperature modification (α-form, rock salt type) and to cesium trihydrogengermanide (thallium iodide type).
    Notes: Kaliumsilanid kristallisiert bei -5°C aus 1,2-Dimethoxyethan/n-Pentan in einer bisher unbekannten Tieftemperatur-Modifikation {β-Form: orthorhombisch, Pnma, Z = 4; a = 880,0(2), b = 541,6(1), c = 682,3(1) pm bei -110 ± 3°C}. Nach den Ergebnissen der Röntgenstrukturanalyse (R = 0,032) baut sich die Verbindung ohne erkennbare Fehlordnung aus isolierten Kalium-Kationen und pyramidalen Silanid-Anionen auf. Zur Koordinationssphäre beider Teilchen gehören sieben Gegenionen (K⃛Si 356 bis 386 pm); beim Anion kommen zwei zusätzliche Kontakte zu gleichnamigen Nachbarn (Si⃛Si 355 pm) hinzu. Die Kristallstruktur stellt eine Defektvariante des Baryt-Typs dar, Verwandtschaft besteht aber auch zur Hochtemperatur-Modifikation (α-Form, Steinsalz-Typ) und zum Caesium-trihydrogengermanidWährend der Name Kaliumsilanid unseres Erachtens eindeutig ist, sollte die homologe Germanium-Verbindung zur Unterscheidung von den binären Phasen Caesium-trihydrogengermanid genannt werden. (Thalliumiodid-Typ).
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895720109
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  • 86
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    Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. 54. Bildung cyclischer Chalkogenide des Typs [Cp2*Zr(μ-E)]2bei der Thermolyse von Permethylzirconocendivinyl in Gegenwart von Schwefel, Selen und Tellur (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 195-198 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Organo Transition Metal Compounds. 54. Formation of Cyclic Chalcogenides of the Type [Cp2*Zr(μ-E)]2 at Thermolysis of Permethylzirconocene Divinyl in Presence of Sulfur, Selenum, and Tellurium4-membered cyclic chalcogenides of the type [Cp2*Zr(μ-E)]2are formed at thermolysis of Cp2*Zr(CH=CH2)2 in presence of sulfur, selenum and tellurium using an aliphatic hydrocarbon as a solvent. During the reactions acetylene and ethylene are liberated in equimolar amounts, which indicates the formation of a zirconocene acetylene ethylene complex as an intermediate.
    Notes: Die Thermolyse von Cp2*Zr(CH=CH2)2 in aliphatischen Kohlenwasserstoffen als Lösungsmittel führt in Gegenwart von Schwefel, Selen und Tellur zur Bildung viergliedriger cyclischer Chalkogenide des Typs [Cp2*Zr(μ-E)]2. Die Reaktionen verlaufen unter Freisetzung äquimolarer Mengen an Acetylen und Ethylen, was auf die intermediäre Bildung eines Zirconocenethylen-acetylen-Komplexes schließen läßt.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/zaac.19895730119
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  • 87
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    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
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895730121
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  • 88
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    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
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895730123
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  • 89
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    Three Bromides of Lanthanum: LaBr2, La2Br5, and LaBr3Dedicated to Professor Reginald Gruehn on the occasion of his 60th birthday on October 6, 1989 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 61-70 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Drei Bromide des Lanthans: LaBr2, La2Br5 und LaBr3Farbloses LaBr3 wurde durch Umsetzung von La2O3 mit NH4Br bzw. in einkristalliner Form durch chemischen Transport mit AlBr3 erhalten. Schwarze Einkristalle von LaBr2 und La2Br5 wachsen aus der Schmelze, die man bei der metallothermischen Reduktion von LaBr3 mit Lithium erhält (verschweißte Tantalampulle, 850°C). Die Kristallstrukturen der drei Lanthanbromide wurden verfeinert: LaBr2. 2H2-Typ, hexagonal (P63/mmc); a = 409,88(4) pm; c = 1 390,0(1) pm; R = Rw = 0,092; La2Br5. Pr2I5-Typ, monoklin (P21/m); a = 789,09(6) pm; b = 424,89(4) pm; c = 1342,3(1) pm β = 91,60(1)º; R = 0,067; Rw = 0,055; LaBr3. UCl3-Typ, hexagonal (P63/m) a = 797,13(4) pm; c = 452,16(4) pm; R = 0,036; Rw = 0,032.
    Notes: Colourless LaBr3 was obtained via the ammonium-bromide route and in singlecrystalline form by chemical vapour-phase transport with aluminium tribromide. Black single crystals of LaBr2 and La2Br5 have been grown from the melts that are obtained by lithium reduction of lanthanum tribromide in sealed tantalum ampoules at 850°C. The crystal structures of the three bromides of lanthanum were refined: LaBr2. 2H2-MoS2 type, hexagonal (P63/mmc), a = 409.88(4) pm, c = 1390.0(1) pm, R = Rw = 0.092; La2Br5. Pr2I5 type, monoclinic (P21/m), a = 789.09(6) pm, b = 424.89(4) pm, c = 1342.3(1) pm, β = 91.60(1)º, R = 0.067, Rw = 0.055; LaBr3. UCl3 type, hexagonal (P63/m), a = 797.13(4) pm, c = 452.16(4) pm, R = 0.036, Rw = 0.032.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895750109
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  • 90
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    2-Heteroatom-1,3-diazole und Chinoxalin als π-Acceptor-Brückenliganden für M(CO)5-Fragmente (M = Cr, Mo, W) Synthese, Elektrochemie, Absorptions- und Emissions-Spektroskopie (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 97-114 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 2-Heteroatom-1,3-diazoles and Quinoxaline as Bridging π Acceptor Ligands for Metal Fragments M(CO)5 (M = Cr, Mo, W). Synthesis, Electrochemistry, Absorption and Emission SpectroscopyMono- and binuclear complexes of M(CO)5 fragments (M = Cr, Mo, W) with the 2,1,3-benzochalcogenadiazoles (chalcogens: O, S, Se) were synthesized and studied by cyclic voltammetry and by UV/Vis absorption and emission spectroscopy. The complexes exhibit low-lying metal-to-ligand charge transfer (MLCT, d → π*) transitions as evident from long wavelength absorptions and are easily reduced to yield persistent anion radicals. The bis(pentacarbonyltungsten) complexes of the sulfur and selenium ligands show weak near infrared (〉750 nm) emission from rather short lived MLCT excited states. While quinoxaline and monocyclic 2,1,3-thiadiazole also form binuclear W(CO)5 complexes, the related 2-methyl-1,2,3-benzotriazole does not bind W(CO)5 fragments in the neutral state but only as the more basic anion radical as evident from ESR spectroscopy.
    Notes: Ein- und zweikernige Komplexe von M(CO)5-Fragmenten (M = Cr, Mo, W) mit den 2,1,3-Benzochalkogenadiazolen (Chalkogene: O, S, Se) wurden dargestellt und durch Cyclovoltammetrie sowie durch UV/Vis-Absorptions- und Emissions-Spektroskopie untersucht. Die Komplexe weisen aufgrund niedrig liegender Metall-Ligand-Charge-Transfer (MLCT, d → π*)-Übergänge langwellige Absorptionen auf und werden leicht zu beständigen Radikalanionen reduziert. Die Bis(pentacarbonylwolfram)-Komplexe der Schwefel- und Selen-Systeme zeigen schwache Emission im nahen Infrarot (〉750 nm) aus sehr kurzlebigen MLCT-angeregten Zuständen. Während Chinoxalin und monocyclisches 2,1,3-Thiadiazol ebenfalls noch Bis(pentacarbonylwolfram)-Komplexe liefern, koordiniert 2-Methyl-1,2,3-benzotriazol W(CO)5-Fragmente nicht im Neutral-Zustand sondern - wie ESR-Untersuchungen zeigen - erst als basisches Radikalanion.
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    URL: http://dx.doi.org/10.1002/zaac.19895750113
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    Ein neuer Perowskit mit Lücken im Anionenteil: Ba4[Na2W2O11]Professor Walter Rüdorff in memoriam (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 154-164 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Perowskite with Deficiencies in the Oxygen Part: Ba4[Na2W2O11]For the first time colourless single crystals of Ba2NaWO5.5 were prepared by reaction of Na4WO5 [2] and „BaO2“ [Ba:Na:W = 4:4:1, Ni-cylinder, 725°C, 35 d]. Single crystal data [432 of 505 I0 (hkl), Four-circle-diffractometer Siemens AED2, MoKα, R = 6.1%, Rw = 5,6%] verify the space group P mmm with a = 579.16(8), b = 580.85(8), c = 859.4(1) pm, Z = 1.The structure is based upon the CaTiO3-type of structure. Ba2+ take the place of Ca2+ meanwhile Ti4+ is substituted alternately by W6+ and Na+. Complete occupation of all lattice positions would lead to a deficite of positive charge. This is compensate by deficiencies in the oxygen part of the lattice. Related to [Na(1)1Na(2)1W(1)1W(2)1O(1)4O(2)2O(3)2O(4)3] these deficiencies are statistically distributed on O(4).Structural relations are deduced by Schlegel-Diagrams. The Madelung Part of Lattice Energie, MAPLE, Effektive Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.
    Notes: Erstmals wurden farblose Einkristalle von Ba4[Na2W2O11] durch Reaktion von Na4WO5 [2] mit „BaO2“ [Ba:Na:W = 4:4:1, Ni-Bömbchen, 725°C, 35 d] dargestellt. Einkristalldaten [432 von 505 I0 (hkl), Vierkreis-Diffraktometer Siemens AED2, MoKα, R = 6,1%, Rw = 5,6%] belegen die Raumgruppe P mmm mit a = 579,16(8), b = 580,85(8), c = 859,4(1) pm, Z = 1.Der Struktur hegt der Perowskit-Typ zugrunde, wobei Ca2+ durch Ba2+ und Ti4+ gesetzmäßig durch W6+ und Na+ ersetzt ist. Das bei vollständiger Besetzung aller Positionen resultierende Defizit positiver Ladung ist durch Lücken im Anionenteil kompensiert. Gemäß [Na(1)1Na(2)1W(1)1W(2)1O(1)4O(2)2O(3)2O(4)3] liegen diese nur bei O(4), statistisch verteilt, vor.Die strukturellen Zusammenhänge werden mit Hilfe von Schlegel-Diagrammen erklärt. Der Madelunganteil der Gitterenergie, MAPLE, sowie Effektive Koordinationszahlen, ECoN, diese über Mittlere Fiktive Ionenradien, MEFIR, berechnet, werden mitgeteilt und diskutiert.
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    URL: http://dx.doi.org/10.1002/zaac.19895750119
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    Die neue Intercalationsverbindung TaS2 · 0,5 C4NH5 Darstellung und physikalische EigenschaftenProfessor Walter Rüdorff in memoriam (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 165-170 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The New Intercalation Compound TaS2 · 0.5 C4NH5. Preparation and Physical PropertiesThe new intercalation compound TaS2 · 0.5 C4NH5 is obtained by reaction of 2H-TaS2 with surplus pyrrol in a closed system at 473 K. The powder diffraction pattern can be indexed based on a hexagonal unit cell with lattice parameters a = 3.315(1) and c = 22.256(7) Å. The temperature induced deintercalation has been studied from 293 to 1073 K. From 677 to 725 K there is a plateau in the TG curve which is attributed to the staging compound TaS2 · 0.33 C4NH5. Up to 1073 K a total mass of 10% has been squeezed out.From 300 to 50 K there is a nearly linear decrease of the resistivity of TaS2 · 0.5 C4NH5 while below 40 K a pronounced ascent has been observed followed by a transition to superconductivity at T ≤ 7,5 K. The degree of polymerized pyrrol in the host structure has been studied using XPS and a N1s signal, 5 eV broad, was monitored which indicates the existence of several sites of differently bonded N atoms.
    Notes: Die neue Intercalationsverbindung TaS2 · 0,5 C4NH5 entsteht bei der direkten Reaktion von 2H-TaS2 mit überschüssigem Pyrrol in geschlossener Ampulle bei einer Temperatur von 473 K. Das Pulverdiagramm der Titelverbindung ist auf Basis einer hexagonalen Zelle indizierbar mit a = 3,315(1) und c = 22,256(7) Å. Die thermische Deintercalation wurde im Temperaturbereich von 293 bis 1073 K untersucht. Zwischen 677 und 725 K deutet ein Plateau im TG-Diagramm auf die Existenz einer Phase der Zusammensetzung TaS2 · 0,33 C4NH5. Bis 1073 K wurde ein Massenverlust von 10% registriert.Im Temperaturbereich von 300 bis 50 K nimmt der Widerstand von TaS2 · 0,5 C4NH5 nahezu linear ab, unterhalb von T = 40 K ist ein ausgeprägter Anstieg zu verzeichnen. Ab T ≤ 7,5 K treten Übergänge in den supraleitenden Zustand auf. Im ESCA Spektrum deutet ein 5 eV breites N1s Signal auf die Existenz von Stickstoffatomen in unterschiedlicher Umgebung.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19895750120
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    Reactions of Tin(II) Fluoride with Halogens (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 202-208 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaktionen von Zinn(II)-fluorid mit HalogenenDurch oxidative Addition von X2 (X = Cl, Br) an SnF2 in Acetonitril wurden die Verbindungen SnF2Cl2(MeCN)2 (monomer) und SnF2Br2(MeCN)2 (polymer oder oligomer) erhalten. Die korrigierten v CN-Valenzschwingungen geben eine Information über die Stärke der Sn-N-Bindung. Die Umsetzungen von SnF2 mit Br2 und I2 in Gegenwart von DMSO bzw. mit I2 in Gegenwart von Pyridin führen bevorzugt zur Disproportionierung gegenüber der Bildung Halogengemischter Verbindungen. Das zeigt, daß die Stabilität der Halogengemischten Verbindungen mit der Differenz der Halogene in ihrer Gruppe abnimmt. Bei der Umsetzung von SnF2 und I2 in Acetonitril entsteht SnF4(MeCN)2. Damit eröffnet sich ein einfacher Weg zum SnF4 und seinen Komplexen, z. B. mit MeCN, das unter milden Bedingungen abgespalten oder durch andere Liganden substituiert werden kann. Mit dieser Methode wurden die Komplexe SnF4L2 (L = DMF, DMSO, THF, Py) dargestellt. Die Struktur der Verbindungen wird auf Grund der IR- und 119Sn-Mößbauer-Spektren diskutiert. Im Fall von SnF4L2 werden die Mößbauer-Verschiebungen und die Sn-F-Daten mit denen der SnCl4L2-Verbindungen verglichen.
    Notes: By oxidative-addition of X2 (X = Cl, Br) to SnF2 in acetonitrile, monomeric SnF2Cl2(MeCN)2 and polymeric or oligomeric SnF2Br2(MeCN)2 are obtained. The corrected v CN IR frequencies provide a good indication of the Sn-N bond strength. The reactions of SnF2 with Br2 and I2 in the presence of DMSO, and with I2 in the presence of pyridine yield the disproportionation products rather than the mixed-halide compounds. That suggests that the stability of the mixedhalide compounds decreases when the difference between the halides increases. The reaction of SnF2 with I2 in acetonitrile gives rise to SnF4(MeCN)2, and provides a simple and inexpensive route to SnF4 and its complexes, as MeCN is lost under mild conditions or substituted by other ligands. In this way we have prepared SnF4L2 (L = DMF, DMSO, THF, Py). The structure of the compounds is discussed in terms of the IR and 119Sn Mössbauer spectra and, in the case of SnF4L2, the Mössbauer isomer shift and the IR v Sn-F compared to the corresponding SnCl4L2 compounds.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/zaac.19895750124
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    Masthead (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 576 (1989) 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895760101
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    Experimente und Modellrechnungen zum chemischen Transport von V2O5 mit NH4Cl (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 240-240 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895750128
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    Professor Lothar Kolditz zum 60. Geburtstage am 30. September 1989 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 576 (1989), S. 7-9 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895760102
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  • 97
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    Study of Equilibria in the Aluminium(III)-Glycine and -Alanine Systems (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 217-228 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Untersuchung der Gleichgewichte in den Aluminium (III)-Glycin- und -Alanin-SystemenDie Bildung verschiedener basischer und gemischt-basischer Komplexe des AlIII-Ions in Gegenwart von Glycin und L-Alanin wurde 0,5 mol dm-3 (Na)NO3-Medium bei 25°C mittels EMK untersucht. Die Konzentration von Aminosäure zu AlIII wurden von 1 : 1 bis 10 : 1 variiert. Die durch die Anwendung der Methode der kleinsten Quadrate erhaltenen Daten weisen in Abwesenheit der Aminosäuren auf die Bildung des Dimeren [Al2(OH)2]4+ und Monomeren [AlOH]2+ mit den Stabilitätskonstanten log β22 = -7,03 ± 0,03 bzw. log β11 = -5,65 ± 0,09. Bei pH-Werten höher als ∼4,0 wird die Bildung des Trimeren [Al3(OH)4]5+ (log β34 = -12,60 ± 0,08) deutlich. In Gegenwart der Aminosäuren wurde der Hinweis auf die Bildung von [Al2(OH)4]2+ (log β24 = -15,65 ± 0,09) gefunden. Neben der Bildung der reinen basischen Komplexe können die im Titel genannten Gleichgewichte unter der Annahme von [Al(OH)3Gly] (log β131 = -7,53 ± 0,04), [Al2(OH)2(Gly)2] (log β222 = 6,56 ± 0.09) und [Al(OH)3Ala] (log β131 = -7,70 ± 0,03), [Al2(OH)2(Ala)2] (log β222 = 7,23 ± 0,07) als Hauptreaktionsprodukte erklärt werden.
    Notes: The formation of various hydrolytic and mixed hydrolytic complexes of the aluminium(III) ion in the presence of glycine and L-alanine, has been studied in 0.5 mol dm-3 (Na)NO3 medium at 25deg;C, by emf method. The concentration ratios of amine acids to aluminium(III) were varied from 1 : 1 to 10 : 1. The least-squares treatment of the data obtained, in the absence of the amino acids, indicates the formation of the dimer, [Al2(OH)2]4+, and monomer, [AlOH]2+, with the stability constants log β22 = -7.03 ± 0.03 and log β11 = -5.65 ± 0.09, respectively. At pH values higher then ∼4.0 formation of the trimer [Al3(OH)4]5+ (log β34 = -12.60 ± 0.08) becomes significant. In the presence of amino acids the evidence has been found for the formation of [Al2(OH)4]2+ (log β24 = -15.65 ± 0.09). Besides the formation of the pure hydrolytic complexes, equilibria in the title systems can be explained by assuming the main reaction products to have the compositions [Al(OH)3Gly] (log β131 = -7.53 ± 0.04), [Al2(OH)2(Gly)2] (log β222 = 6.56 ± 0.09) and [Al(OH)3Ala] (log β131 = -7.70 ± 0.03), [Al2(OH)2Ala2] (log β222 = 7.23 ± 0.07).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895750126
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    Untersuchungen zum thermischen Verhalten unterschiedlicher ZSM-5-ZeolitheProfessor Lothar Kolditz zum 60. Geburtstage gewidmet (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 576 (1989), S. 65-70 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on the Thermal Stability of Different ZSM-5 ZeolitesThe thermal stability of ZSM-5 zeolites with different crystalform, Na2O content, and different ratio SiO2/Al2O3 was measured by determination of the benzene adsorption capacity of the products after heating at 600-1200°C. The results reveal the influence of the crystal form and especially of the Na2O content on the thermal stability. The thermal stability of ZSM-5 zeolites with the same crystal form decreases with increasing Na2O content. A dependence on the ratio SiO2/Al2O3 in the ZSM-5 zeolites was not observed.
    Notes: Die thermische Stabilität von ZSM-5-Zeolithen mit unterschiedlicher Kristallform, unterschiedlichem Verhältnis SiO2/Al2O3 wurde durch Messung der Benzoladsorptionskapazität nach dem Erhitzen der Produkte auf 600 bis 1200°C bestimmt. Die Kristallform und der Na2O-Gehalt der ZSM-5-Zeolithe beeinflussen die thermische Beständigkeit. Bei gleicher Kristallform sinkt die Thermostabilität mit steigendem Na2O-Gehalt der Zeolithe. Eine Abhängigkeit der thermischen Beständigkeit vom Verhältnis SiO2/Al2O3 des Gitters wurde nicht beobachtet.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895760109
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    27Al-MAS-NMR-Untersuchung der Thermolyse von Hexaaquaaluminium-chlorid, [Al(H2O)6]Cl3 [1]Professor Lothar Kolditz zum 60. Geburtstage gewidmet (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 576 (1989), S. 43-53 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 27Al MAS NMR Studies on the Thermolysis of the Hexaaqua Aluminium Chloride [Al(H2O)6]Cl3Products of the thermolysis of the hexaaqua aluminium chloride [Al(H2O)6]Cl3 were prepared by keeping the dried educt for one hour under dried air flow at the selected temperature. Already after a pretreatment at 160°C, in addition to the signal of Aloct structural units, a new signal at 32 ppm is observed in the 27Al MAS NMR spectrum. After a small shift to 35 ppm this signal distinctly appears from 400°C up to 750°C, partially even dominating beside the signals of Aloct and Altet structural units. The samples calcined at 800 and 1000°C provide the known two-peak spectrum of γ-Al2O3. The chemical shifts of all of these peaks show characteristical values for the temperature ranges 〈 350°C, 400-750°C and 750-1000°C.After contact with water the samples primarily showing a three-peak spectrum give only rise to the Aloct peak. The sharp peak at 35 ppm which was already observed in the spectra of other strongly disordered aluminium-oxygen compounds as, e.g., metakaolinite, is assigned to relatively weak-distorted AlO5 units of trigonal bipyramidal structure.
    Notes: Thermolyseprodukte des Hexaaquaaluminium-chlorids, [Al(H2O)6]Cl3, wurden hergestellt, indem Proben des trockenen Eduktes jeweils eine Stunde im getrockneten Luftstrom bei den angegebenen Temperaturen gehalten wurden. Bereits nach einer Vorbehandlung bei 160°C ist im 27Al-MAS-NMR-Spektrum neben dem Signal der Alokt-Baugruppen ein neues Signal bei 32 ppm zu beobachten. Es ist, nach einer leichten Verschiebung auf etwa 35 ppm ab 400°C, bis 750°C eindeutig, z. T. dominierend, neben den Signalen der Alokt- und Altet-Baugruppen wahrzunehmen. Die auf 800 und 1000°C erhitzten Proben geben das bekannte 2-Peak-Spektrum des zunehmen. γ-Al2O3. Die chemischen Verschiebungen aller drei Signale nehmen für die Temperaturintervalle 〈 350°C; 400-750°C und 750-1000°C charakteristische Werte an. Proben mit dem 3-Peak-Spektrum zeigen nach Kontakt mit Wasser fast nur noch den Alokt-Peak. Das scharfe Signal bei 35 ppm, das bereits in anderen hoch-fehlgeordneten oxidischen Aluminium-Verbindungen, wie z. B. Metakaolinit, beobachtet wurde, wird auf relativ gering verzerrte AlO5-Baugruppen trigonal-bipyramidaler Struktur zurückgeführt.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895760107
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    Redoxreaktionen in kondensierten Oxidsystemen. X Bildung von Defektspinellen und Phasenbeziehungen im System NixMn3-xO4Professor Lothar Kolditz zum 60. Geburtstage gewidmet (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 576 (1989), S. 71-80 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Redox Reactions in Condensed Oxide Systems. X. Formation of Defect Spinels and Phase Relations in the System NixMn3-xO4The phase diagram of the system NixMn3-xO4 is reported to be completed by the formation of a defect spinel phase in the range of lower temperature. Highly dispersed powders NixMn3-x□3δ/4O4+δ (0.16 ≤x≤ 1.67) result from heating of oxalate mixed crystals up to 350°C in air or oxygen. They are shown to be appropriate as precursors yielding a reproducible structure of ceramics, e. g. of the spinel NiMn2O4, in the result of sintering.
    Notes: Es wird über das Auftreten einer Defektspinellphase im System NixMn3-xO4 berichtet, die das bisher bekannte Phasendiagramm im Bereich niedrigerer Temperaturen ergänzt. Oxalatmischkristalle ergeben beim Erhitzen auf 350°C an der Luft bzw. unter Sauerstoff hochdisperse Pulver NixMn3-x□3δ/4O4+δ (0,16 ≤x≤ 1,67), die sich im Zusammensetzungsbereich der Spinellphase, z. B. NiMn2O4 (x = 1), als geeignete Vorstufen erweisen, um die reproduzierbare Ausbildung eines Keramikgefüges zu erreichen.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895760110
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