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  • 1985-1989  (1,606)
  • 1965-1969
  • 1988  (709)
  • 1985  (897)
  • Inorganic Chemistry  (1,424)
  • Ultrastructure
  • 1
    ISSN: 1432-2285
    Keywords: Nuclear crystalloid inclusions ; Olea europaea ; Cytochemistry ; Ultrastructure ; Glycoprotein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The nuclei of mesophyll cells of olive trees contain numerous sizeable crystalloid inclusions. Cytochemical examination using epoxy resin-embedded, semithin-sectioned tissue indicated the presence of proteins and oligoor polysaccharides in these inclusions. Their electron microscopical analysis revealed a crystalline substructure consisting of intersected subunits of high order. The spacing of the lattice fibrils and the angles of intersection were determined and used to establish a model of the unit cell of crystallization. It is suggested that the nuclear crystalloids of olive trees consist of glycoprotein molecules. They differ from the intranuclear crystalloids observed in other species predominantly in the high density of their subunit arrangement.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-2307
    Keywords: Collagenous colitis ; Myofibroblasts ; Myoid cells ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We examined 129 colonic biopsies from 21 patients with collagenous colitis, most of whom presented with diarrhoea. Morphometric measurements gave a mean thickness of the subepithelial collagen deposit of 19.5 µ ± 5.1. The trapped fusiform and/or stellate cells within the deposits were identified immunohistochemically as myoid cells, being positive with antibody against smooth muscle cell alpha-actin. Ultrastructurally, these cells have all the characteristic features of myofibroblasts. Similar cells are also present along the crypts, where they were formerly referred to as pericryptal fibroblasts. Although there is still much debate as to the pathogenesis of this condition, we would like to suggest that collagenous colitis is a disease of pericryptal myofibroblasts. During their migration and maturation into the subepithelial region they may synthesize an excess of collagen, under some yet unknown or undefined stimulus/stimuli.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Sexual plant reproduction 1 (1988), S. 208-216 
    ISSN: 1432-2145
    Keywords: Megagametophyte ; Synergids ; Brassica campestris ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In Brassica campestris, both synergids of the ovule degenerate before the arrival of the pollen tube. Synergid degeneration does not depend on pollination. At the non-degenerated stage, the synergids are completely filled with a complexly organized cytoplasm containing numerous mitochondria with many cristae, a large number of dictyosomes with many associated vesicles, and a very extensive rough endoplasmic reticulum. The degenerative changes that occur in the cytoplasm of the synergids are characterized by a loss of visibility of the membranes of the endoplasmic reticulum and the simultaneous formation of dense deposits on the surrounding membranes of the mitochondria. Locally, the plasma membranes of the synergids disappear, and some ground plasma of the synergids penetrates into the space between the plasma membranes of the egg cell and the central cell.
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  • 4
    ISSN: 1432-2013
    Keywords: Isolated cardiac myocytes ; Electrical activity ; Contraction ; Fatty acids ; Ultrastructure ; Diabetes mellitus, experimental ; Streptozotocin ; Electrophysiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of chronic experimental diabetes on electrophysiological properties, contractile behavior,45Ca2+ transport, fatty acid profiles and ultrastructural characteristics were studied in enzymatically dissociated ventricular myocytes. Diabetes was induced in rats by streptozotocin administration and animals were killed 8–10 weeks later. Myocytes from diabetic rats exhibited electrical behavior similar to that of myocytes from control rats, but their contractile properties were altered. Their sensitivity of the twitch contractions to various positive and negative inotropic agents (isoproterenol, norepinephrine, phenylephrine, acetylcholine, ouabain and veratridine) was greatly diminished. However, a part of the contractile response (the tonic, sustained contractions) were increased in the diabetic myocytes, indicating that the changes are not caused by a decreased sensitivity of myofilaments. Furthermore, the diabetic myocytes exhibited also significant decrease in total Ca2+ content. The fatty acid profile in the diabetic group was changed mainly in that there were slightly elevated levels of docosahexaenoic acid and diminished levels of palmitic acid. The ultrastructure of the diabetic myocytes was affected only slightly. These investigations offer for the first time a comprehensive picture of changes related to diabetic cardiomyopathy as they occur at the level of cardiomyocytes.
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  • 5
    ISSN: 1432-2307
    Keywords: Insulin ; Insulinomas ; Ultrastructure ; Immunogold technique
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Localisation of insulin-like immunoreactivity has been studied using the immunogold staining procedure on thin sections of 6 human insulinomas, conventionally processed for electron microscopy. The labelling was restricted to the secretory granules. Depending on their morphology, these either resembled B-cell granules of human adult pancreas or belonged to the atypical (non-diagnostic) group. Within the former group, those with a crystalloid core or an amorphous dense or moderately dense core were strongly immunoreactive, whereas others, filled with a pale material, were poorly labelled. Most granules of this type were stored together within the heavily granulated cells of 3 insulinomas, presenting the classical features of clinical and biological behaviour and a typical light microscopic staining pattern. In contrast, the non-diagnostic granules, characterized by their smaller size, a very dense core and a thin halo, were mainly found within the poorly granulated cells making up the other tumours, and showed a very uneven labelling. Strongly labelled granules were found in one insulinoma that also belonged to the classical type; these were stored together with a few diagnostic granules within the same cells. Only poorly labelled atypical granules were present in two cases revealing a number of unusual features; these included moderate elevation of insulinaemia, uncertain tumour histology, as well as weak immunostaining for insulin/proinsulin and variable argyrophilia of the tumour in paraffin sections. These findings suggest that human insulinomas differ not only in storage capacity but also in their degree of granule maturation. This may involve some deficiency of either the prohormone conversion or the subsequent processing of the cleavage products.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 412 (1988), S. 563-572 
    ISSN: 1432-2307
    Keywords: Cat scratch disease ; Epidemiology ; Ultrastructure ; Bacterial morphology ; Warthin-Starry stain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The aetiological agent of cat scratch disease (CSD) has been unknown for more than 30 years. Recently, a micro-organism clearly shown with Warthin-Starry silver (W-S) stain was found and thought to be a possible cause of the disease. In this study, 32 cases of regional lymphadenopathy histologically compatible with CSD and 20 contrasting cases of lymphadenopathy were examined retrospectively with W-S stain. W-S positive pleomorphic organisms were clearly demonstrated in 20 of the 32 suspected cases of CSD, but in none of the other cases. The onset of disease in these 20 cases with W-S positive organisms occurred between July and January. This seasonal variation in the onset of disease was highly significant (P〈0.005) and was not due to a single epidemic. Moreover, some characteristic morphological features of the organism were found by electron microscopic observations. Ultrastructurally, the organism was a bacterium showing a chain-like arrangement, septal formation, branching and clubbed ends.
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  • 7
    ISSN: 1432-2307
    Keywords: Lipid rich carcinoma ; Breast ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Five cases of lipid-rich carcinomas of the breast were investigated ultrastructurally and immunohistochemically for alpha-lactalbumin (ALA), lactoferrin (Lfr) and human milk fat globule membrane antigen (HMFG-2). Staining for ALA and Lfr showed intensive reaction on nearly all of the tumour cells whereas immunoreaction for HMFG-2 revealed positivity in single cells. All tumours were negative for steroid receptor content. Ultrastructurally the tumour cells showed numerous intracytoplasmic non-membrane bound lipid droplets which were often found within autophagocytic vacuoles. Neither rough endoplasmic reticulum nor Golgi complexes showed any sign of lipid synthesis. Extrusion of lipid droplets and extracellular lipid deposition was not observed. In conclusion, our findings do not justify the consideration of lipid-rich carcinoma of the breast as a clearly defined group of tumours with specific secretory activity. Therefore, the term lipid-rich carcinoma should be used in preference to lipid-secreting, unless there is evidence of active lipid secretion.
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  • 8
    ISSN: 1432-0533
    Keywords: Amyotrophic lateral sclerosis ; Chromatolysis ; Ultrastructure ; Motor neuron disease ; Hyaline intraneuronal inclusions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural features of chromatolytic neurons observed in a sporadic case with amyotrophic lateral sclerosis (ALS) are reported. A 70-year-old woman died of weakness and atrophy of the four limbs, bulbar and facial muscles, and hyperreflexia, of 3 1/2 years' duration. Neuronal loss was marked in the anterior horn of the spinal cord, with degeneration of the pyramidal tracts. Most of the remaining neurons showed chromatolysis. Some of the chromatolytic neurons contained faintly eosinophilic inclusions with a halo. Few spheroids were observed. Hypoglossal nuclei, nucleus ambiguus, motor nuclei of N. VII and N.V were well populated, but contained several chromatolytic neurons. Ultrastructurally, the chromatolytic neurons contained aggregates of fibrils thicker than the 10-nm neurofilaments. These fibrils were arranged randomly, and were closely associated with granular materials as well as rough endoplasmic reticulum. Neurofilamentous accumulations reported to be common in sporadic ALS were rare in this case. No Bunina body was observed.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 76 (1988), S. 11-16 
    ISSN: 1432-0533
    Keywords: Choroid plexus ; Cytoplasmic inclusion ; Histochemistry ; Ultrastructure ; Frequency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We described a new type of cytoplasmic inclusion in the choroidal epithelial cells of humans. The inclusions usually appeared as brown, round or elongated bodies with or without an inner core, ranging in size from 1.3 to 7.0 μm. Histochemically, they contained polysaccharides, proteins and compound lipids. Ultrastructurally, they were composed of finely granular and filamentous materials, which are densely packed in the inner core and less dense in the outer zone. The frequency study of the inclusions in 197 autopsied patients revealed that their occurrence had no correlation with the age or the disease category. It is concluded that the inclusions are a nonspecific, but peculiar, change of the choroidal epithelial cells, probably representing the morphological expression of a physiological or pathological alteration of the cellular metabolism at the single-cell level.
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  • 10
    ISSN: 1432-0533
    Keywords: Creutzfeldt-Jakob disease ; Slow virus ; Pathology ; Ultrastructure ; Intranuclear vacuolar inclusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a 53-year-old man with a progressive mental deterioration and myoclonic jerks, brain biopsy failed to show any significant light microscopical findings. Electron microscopy revealed membranebound vacuolar inclusions in many neuronal nuclei as the only prominent finding. Hamsters intracerebrally inoculated with the biopsy material demonstrated typical spongiform changes in the gray structures of the brain when sacrificed on the 309th and 332nd days post inoculation, characteristic of experimental Creutzfeldt-Jakob disease (CJD). These intranuclear vacuolar inclusions, originally reported in experimental Creutzfeldt-Jakob disease in this laboratory, may be a valuable electron microscopic feature in some CJD cases and may play an important role in supporting the diagnosis of CJD.
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 178 (1988), S. 47-52 
    ISSN: 1432-0568
    Keywords: Ultrastructure ; In vitro fertilization ; Bovine ; Ova ; Cortical granules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cumulus-oocyte complexes collected from cows at an abattoir by aspiration from small (1–6 mm) antral follicles were matured and inseminated in vitro. At different time intervals after insemination the ova were processed for transmission electron microscopy. Up to and including 6 h after insemination all ova were unfertilized, and their cortical granules were more or less clustered. At 6 h acrosome reaction of spermatozoa was observed on the surface of the zona pellucida. At 8 h the first fertilized ovum appeared and the first fully developed spherical pronucleus was observed, at 20 h the first apposition of pronuclei was seen, and at 40 h divisions were ongoing or completed. More than one third of the fertilized ova showed polyspermic penetration of the zona pellucida, and in most of these ova different developmental stages of supernumerary pronucleus formation were observed in the ooplasm. Abnormal cortical granule release was seen in approximately half of the fertilized ova, and it was more frequent in ova with polyspermic as opposed to monospermic penetration of the zona pellucida.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 178 (1988), S. 41-46 
    ISSN: 1432-0568
    Keywords: In vitro fertilization ; Bovine ; Ultrastructure ; Ova ; Spermatozoa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cumulus-oocyte complexes were collected from cows at an abattoir by aspiration from small (1–6 mm) follicles. The complexes were matured in vitro for 28 h. Subsequently, the cumulus cells and the zona pellucida were removed by enzyme treatment in a proportion of the complexes (zona-free ova). Both cumulus-enclosed and zonafree ova were inseminated in vitro and processed for scanning electron microscopy after different periods of culture. In the cumulus-enclosed ova the number of spermatozoa attached to and penetrating into the cumulus investment increased with increasing culture time. Practically all spermatozoa displayed intact acrosomes. In the zona-free ova clusters of spermatozoa attached to the ovum surface, and at 5 h a proportion of the spermatozoa had undergone the acrosome reaction, and their internalization into the ooplasma was initiated. The acrosome reaction was characterized by an increasing fenestration of the membrane coverings of the acrosomal region of the sperm head. During the sperm head internalization, where the ovum microvilli appeared to contact especially the equatorial segment and the postacrosomal region, the sperm head gradually disappeared from the ovum surface, and the microvilli at the site of internalization became more bulbous. Simultaneous abstriction of the second polar body was seen in some ova.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 280 (1988), S. 308-318 
    ISSN: 1432-069X
    Keywords: Pili annulati ; Ultrastructure ; DACM staining ; Hair cortex ; Protein metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Plucked scalp hairs and hair roots of pili annulati were examined to understand their pathogenesis. Stereoscopic examinations of hairs in transmitted light and/or reflected light and light microscopic surveys of the cross-sections of hairs confirmed that the cortical empty spaces appeared to be responsible to the unique dotted shiny appearance of the hairs seen by the unaided eyes under a refracted light. By transmission electron microscope, small vacuoles and dense bodies were observed in the cytoplasm of the differentiating cortical cells; subsequently, with increasing number of tonofilaments, an uneven distribution of free ribosomes occurred and abnormal spaces containing fine granular substances were formed in the cytoplasm of the cortical cells. Occasionally, extremely large cortical trichohyaline granules were found. In the keratinized hair, irregular empty spaces were present in the cortex of the abnormal hair segments. Histochemically, the keratinized cortex of the affected hairs always had more residual SH groups than the controls. Pili annulati may be a disorder of protein metabolism involving a partial dysfunction of cytoplasmic ribosomes, resulting in a lack of cortical keratin formation.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 76 (1988), S. 522-527 
    ISSN: 1432-0533
    Keywords: Esthesioneuroblastoma ; Tyrosine hydroxylase (TH) ; Immunohistochemistry ; Ultrastructure ; Catecholamine-producing tumor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An esthesioneuroblastoma in a 16-year-old male was studied ultrastructurally and immunohistochemically, using antiserum against tyrosine hydroxylase (TH), a rate-limiting enzyme in the catecholamine-synthesizing pathway. Tumor cells were fairly uniform in appearance, showing scantly cosinophilic cytoplasm and round to oval hyperchromatic nuclei, and were arranged in nests and cords of various sizes. Ultrastructurally, individual tumor cells had well-developed cell organelles including polyribosomes, microtubules, intermediate filaments, centrioles, Golgi apparatus and mitochondria. Secretory-like granules were occasionally found, predominantly in the cell processes. Immunohistochemically, many tumor cells were shown to be immunoreactive for TH. This finding strongly suggested that the present tumor was capable of producing catecholamines and that it might be derived from certain sympathetic neuronal cell nests in the superior nasal cavity.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 75 (1988), S. 577-582 
    ISSN: 1432-0533
    Keywords: Cytoplasmic bodies ; Emetine ; Myopathy ; Sarcomeric lesions ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Progressive myopathy developed in two women who consumed ipecac syrup containing emetine hydrochloride to induce vomiting as part of their anorexia nervosa. Muscle biopsy specimens were characterized by severe disruption of the sarcomeres. The ultrastructural spectrum extended from “Z-band streaming” to the formation of cytoplasmic bodies and also comprised abnormalities of the sarcotubular system, thus suggesting that muscle weakness may be related to both sarcomeric and sarcotubular lesions in this self-inflicted myopathy. It is tempting to suggest that muscle weakness may be correlated with or based on the pathology in sarcomeres and the sarcotubular system. As the myopathy is clinically reversible upon discontinuation of ipecac consumption the morphological findings should also be potentially reversible. Experimentally induced emetine myopathy may, thus, serve as a useful model to study morphological dynamics of sarcomeric lesions, which may be observed separately or simultaneously in a variety of spontaneously occurring human neuromuscular disorders.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 76 (1988), S. 101-106 
    ISSN: 1432-0533
    Keywords: AIDS ; Confronting cylindrical cisterns ; Cytomembranous inclusions ; Tubuloreticular inclusions ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural studies of cells and tissues in the acquired immunodeficiency syndrome (AIDS) have revealed two distinct cytomembranous inclusions referred to as “tubuloreticular inclusions” (TRI) and “confronting cylindrical cisterns” (CCC). TRI are found most often in leukocytes and endothelial cells in conditions with elevated levels of alpha-interferon, such as viral infections, autoimmune diseases and certain neoplasms. On the other hand, CCC are detected almost exclusively in mononuclear inflammatory cells and are limited to a few conditions, of which AIDS is the most common. CCC have been proposed as an ultrastructural marker for human immunodeficiency virus (HIV) infection. We describe CCC in mononuclear inflammatory cells in the brain of a patient with AIDS. Finding CCC in brain tissue with no other specific feature such as multinucleated giant cells, nevertheless, should alert the neuropathologist to the possibility that the patient might have AIDS.
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  • 17
    ISSN: 1432-0568
    Keywords: Hyperoxia ; Hypoxia ; Teratogenesis ; Rat embryo ; Whole-embryo culture ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary By using a whole-embryo culture technique (New 1978), the effects of oxygen concentration (5%, 20% and 95% oxygen) on embryonic development in the rat were investigated by light and electron microscopy. The best embryonic development occurred when the 9.5-day-old embryos were cultured for 24 h with 5% oxygen, and the 10.5-day-old embryos with 20% oxygen (optimum oxygen concentration). When the 9.5- and 10.5-day-old embryos were cultured for 24 h with too little or too much oxygen, retardation of the embryonic growth and abnormal development was observed. Using light microscopy, numerous degenerating cells, exhibiting granular deposits in the cytoplasm, were seen, but the distribution of the degenerating cells was quite different between the two groups. With electron microscopy, the most striking feature of the degenerating cells in the embryos cultured with too little oxygen, was the extreme swelling of the mitochondria without any morphological alterations of the nucleus or the other cell organelles. On the other hand, the characteristic feature of the degenerating cells in the embryos exposed to too much oxygen, was the formation of phagolysosomes in the cytoplasm. Morphological alterations of the nucleus or mitochondria were not evident. In the present study, the possible teratogenic mechanism of too much or too little oxygen in the whole-embryo culture of the rat embryo is discussed.
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 177 (1988), S. 403-408 
    ISSN: 1432-0568
    Keywords: Marsupial ; Newborn ; Ultrastructure ; Merkel cells ; Mechanoreceptor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of the epidermal cells surrounding the mouth of three newborn marsupial species, the Northern native cat Dasyurus hallucatus, the brush tail possum Trichosurus vulpecula and the Northern brown bandicoot Isoodon macrourus were examined. The presence of Merkel cells, highly sensitive touch receptors, would suggest that the sense of touch aids the relatively underdeveloped newborn marsupial to move from the urinogenital sinus to the pouch and to locate the teat.
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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 179 (1988), S. 191-203 
    ISSN: 1432-0568
    Keywords: Sertoli cell ; Spermatogenic cycle ; Ultrastructure ; Stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of Sertoli cells from selected stages of the spermatogenic cycle was assessed by morphometric analysis which showed significant changes in the morphological features of Sertoli cell cytoplasm at the commencement of the cycle (stage II) compared to the middle (stages VII-VIII) and the completion of the cycle (stages IX-XIV). Total volume and surface area of organelles (rough and smooth endoplasmic reticulum (ER), lysosomes, mitochondria and Golgi) exhibited stage-dependent and cyclic variations as did the total surface area of Sertoli cell plasma membrane. Polarization of cytoplasmic organelles to basal or columnar regions of the Sertoli cell, exhibited particularly by the Golgi, rough ER and lysosomes also showed marked cyclic fluctuations during the spermatogenic cycle. Rough and smooth ER exhibited the most dramatic stage-dependent changes in total volume and surface area the former being respectively largest and smallest in stages VII-VIII and XIII-XIV, the latter organelle presenting the reverse pattern in these two groups of stages. Similar stage-dependent alterations of lysosome volume and surface area were also noted, being maximal during stages XIII-XIV-II and reaching a nadir at stage VIII. Although the functional role of most Sertoli cell organelles and inclusions remain largely unknown, the present study suggests that the cyclic and stage-dependent variations in ultrastructure probably reflect major changes in Sertoli cell function necessary for the regulation of the spermatogenic cycle.
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  • 20
    ISSN: 1432-1076
    Keywords: Infantile Refsum disease ; Phytanic acid ; Dietary treatment ; Peroxisomes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two patients with infantile phytanic acid storage disease (infantile Refsum disease), one of whom showed the presence of morphologically normal peroxisomes in a liver biopsy, were treated with a low phytanic acid diet for more than 2 years and the effects of treatment on certain clinical, biochemical and ultrastructural parameters were examined. Both patients showed evidence of either an improvement or stabilisation in their clinical condition. Plasma phytanic acid levels decreased to near normal values in approximately 6 weeks after the introduction of the diet; plasma pipecolic acid also declined markedly but the decrease was not so rapid and its level remained abnormal. C26∶C22 fatty acid ratios decreased very slowly and even after 2 years the values remained grossly abnormal. Despite the marked reduction of phytanic acid in the liver, there was an increase in the C26∶C22 fatty acid ratios and this appeared to be paralleled by an increase in inclusion bodies. Our data suggest that some patients with the infantile form of Refsum disease may show some clinical benefit from dietary management and this is reflected biochemically by decreases in the plasma levels of phytanic acid and pipecolic acid.
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  • 21
    ISSN: 1432-0738
    Keywords: Cadmium ; Ultrastructure ; In vitro ; Nucleus ; Cytoplasm ; Muntjac
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A detailed electron microscopy study of cadmium sensitive and resistant muntjac fibroblast cell lines has identified a wide range of intracellular damage following exposure to cadmium. Damaged organelles included cell membrane, mitochondria, Golgi cisternae and tubular network, chromatin, nucleoli, microfilaments and ribosomes. Although cell membrane damage was generally the earliest indication of adverse cadmium action, particularly with continuous cadmium exposures, cells could tolerate extensive membrane loss. Mitochondrial distortion and some damage to Golgi was also tolerated. The turning point at which cadmium became lethal was generally marked by a cascade of events which included damage to both nuclear and cytoplasmic components. These results for fibroblasts are discussed and compared with damage reported in other types of cells.
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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 280 (1988), S. 338-345 
    ISSN: 1432-069X
    Keywords: Port wine stain ; Endothelium ; Basement membrane ; Collagen ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cause for the progressive vascular dilatation in port wine stains remains unclear. We compared the histology and ultrastructure of lesional and adjacent normal skin in paired biopsy specimens of 12 and 8 patients, respectively (age range, 6 to 53 years). In semithin sections, the lesions of all patients showed ectatic vessels and a fine-fibrous or hyaline thickening of the walls of postcapillary venules, as well as in some instances a loosening of the surrounding connective tissue. Ultrastructurally, the wall material consisted predominantly of peripheral deposits of amorphous material interspersed with collagen fibrils (diameter, 35±4 nm); occasionally the number of basal laminae in the inner part was also increased. Cross-banded filamentous aggregates with a periodicity of 95 nm were observed in and around the walls. The endothelium of many patients displayed fenestrations and/or small gaps. Various kinds of alterations of the intervascular connective tissue were found. We conclude that structural alterations of the vascular and later also of the intervascular connective tissue are related to the dilatation of the vessels. These findings are in agreement with the immunopathologically demonstrated increase of basement membrane components in the same biopsy specimens, but are interpreted as secondary phenomena. Endothelial stability and permeability may also be affected.
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  • 23
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 280 (1988), S. 319-322 
    ISSN: 1432-069X
    Keywords: Elastosis perforans serpiginosa ; Collagen fibrils ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
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  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 69 (1988), S. 662-666 
    ISSN: 1432-1106
    Keywords: Serotonin ; Lateral geniculate nucleus ; Monkeys ; Ultrastructure ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Serotonin-immunoreactivity in the monkey lateral geniculate nucleus appears as a plexus of fine, beaded fibers decreasing in density from magnocellular to parvocellular laminae. Ultrastructurally, these fibers show strictures and dilations, and are filled with dense round particles as well as granular material attached to outer mitochondrial membranes and microtubules. Most of the profiles followed in serial sections lack morphologically defined synapses. The few synapses observed are asymmetric, some with subjunctional dense bodies. This appearance suggests a possible excitatory effect mainly on interneurons which in turn would inhibit principal cells. Serotonin released non-synaptically may block the delivery of transmitters from retinal terminals and/or the receptors for such transmitters, thereby exerting a modulatory depressing action on principal cells.
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  • 25
    ISSN: 1432-1106
    Keywords: Cholinergic toxin ; Retina ; Optic tectum ; ChAT ; Ultrastructure ; Goldfish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary AF64A, a presumed selective cholinergic neurotoxin has been used to study the effect on cholinergic systems of the goldfish retina and optic tectum. Toxin injection in the vitreum and in the optic tectum caused a selective decrease of choline acetyltransferase activity in both areas, while no significant decrease of glutamate decarboxylase and D-3H aspartate uptake were observed at different times after the injections. The effect was particularly dramatic in the retina of long term-injected animals, where choline acetyltransferase dropped to practically zero level. The ultrastructural analysis showed selective degeneration of some neurons in the amacrine and ganglion cell layer of the retina as well as of synaptic terminals and neuronal cell bodies in the optic tectum. The results favour a selective cholinotoxicity of AF64A in fish nerve tissue at doses substantially higher than those found to have additional unselective effects in mammals.
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  • 26
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    Experimental brain research 72 (1988), S. 473-480 
    ISSN: 1432-1106
    Keywords: Serotonin ; Tyrosine hydroxylase ; Zona incerta ; Regeneration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cellular relationships between serotonin (5-HT) axons and tyrosine hydroxylase (TH)-containing neurons were examined by combined (3H)5-HT uptake radioautography and TH immunocytochemistry in the medial zona incerta (ZI) of adult rats, 7 and 50 days after an intracerebral injection of 5,7-Dihydroxytryptamine (5,7-DHT). Seven days post-lesion, only rare, scattered (3H)5-HT-labeled axon terminals were apparent in the zone of the medial ZI accessible to intraventricularly injected (3H)5-HT. In contrast, in sham-injected animals (3H)5-HT-labeled varicosities were numerous and often observed adjacent to TH-immunoreactive perikarya and dendrites. Fifty days post 5,7-DHT injection, the density of (3H)5-HT-labeled terminals approximated that seen in sham-treated animals. At the ultrastructural level, these regenerated 5-HT axons were similar in size, shape and content to those observed in sham-operated rats. Also, as in sham, some of the (3H)5-HT-labeled axons were directly apposed to TH-immunopositive labeled profiles. The latter included large dendritic shafts and dendritic spines, but only rare perikarya. In both sham- and 5,7-DHT-treated animals a few of the contacts between (3H)5-HT-labeled and TH-immunoreactive profiles exhibited an asymmetric synaptic differentiation. These results indicate that 5-HT fibers in the medial ZI, following regeneration, can reestablish normal relationships and even synapses with a given population of chemically identified cells.
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  • 27
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    Experimental brain research 69 (1988), S. 522-530 
    ISSN: 1432-1106
    Keywords: Estrogen ; Synapse ; Ultrastructure ; Midbrain central gray ; Lordosis behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Axons of ventromedial hypothalamic (VMH) neurons have been previously shown to terminate in the midbrain central gray (MCG) (Chung et al. 1984, 1986). Since VMH synapses in this region may be involved in the mediation of estrogen-induced lordosis behavior, we examined the effect of estrogen on the morphology of synapses in the MCG. Ovariectomized adult female rats were given daily subcutaneous injections of estradiol benzoate (10 μg) or the vehicle control and after 20 days of injection, only the estrogen-treated rats showed the lordosis response. A quantitative analysis of MCG tissue from these animals demonstrates morphological changes in various synaptic parameters with estrogen treatment including: 1) an increase in the mean number of dense-cored vesicles and an increase in the number of terminals containing densecored vesicles, 2) an increase in the length of postsynaptic densities (PSDs), 3) an increase in the number of PSDs showing perforations, 4) an increase in the number of synapses, and 5) an increase in the number of synapses with positive synaptic curvature. No alterations in the number of subjunctional bodies were observed. The dense-cored vesicles may contain an estrogen-induced trophic factor which may function in maintaining the integrity of postsynaptic processes and cells in the MCG with which VMN endings contact (Chung et al. submitted) and/or which induces morphological changes in postsynaptic structures which facilitate the effects of estrogen on lordosis behavior.
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  • 28
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    Rheumatology international 8 (1988), S. 171-176 
    ISSN: 1437-160X
    Keywords: Ultrastructure ; Synovium ; Macrophages ; Immunoelectron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural localisation of class II and macrophage antigens has been sought in the intimal layer of the human synovium. The cells described as type A in early morphological studies are shown to express both class II antigens and two markers of the macrophage/monocyte lineage of cells, OKM1 and MAB 24. The morphological type B cells were found to express none of these antigens. The findings are consistent with the idea that the synovial lining comprises two cell types, bone-marrow derived macrophages and mesenchymal fibroblasts.
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  • 29
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    European archives of oto-rhino-laryngology and head & neck 245 (1988), S. 266-272 
    ISSN: 1434-4726
    Keywords: Murine endolymphatic sac ; Basement membrane ; Fluid transport ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of the basement membrane of the murine endolymphatic sac was studied under various experimental conditions in labyrinthectomized and ethacrynic acid-treated animals and was compared with normal anatomy. The basement membrane was clearly visualized after staining with ruthenium red or dialyzed iron. The basement membrane of the murine sac consists of two different layers: the lamina rara and the lamina densa. It demarcates the border between the epithelial cells and the subepithelial connective tissue. Our findings suggest that the basement membrane acts as a physical support to the epithelium in the endolymphatic sac. The basement membrane also shows a dynamic capacity to form a new basement membrane, with the result that the lateral intercellular space between contiguous epithelial cells may be integrated with the subepithelial space. This system is believed to act as a macromolecular and bulk water transport system. In the subepithelial space, collagen, reticular and elastic fibrils are found having a close relationship to the basement membrane. The elastic fibres are presumed to play a role in the pressure-regulating mechanism in the endolymphatic sac.
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  • 30
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    Environmental biology of fishes 22 (1988), S. 69-77 
    ISSN: 1573-5133
    Keywords: Acid ; Metals ; Ultrastructure ; Olfaction ; Electrical response ; Pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The effects of acid ((H2SO4) and aluminum AIKSO4 in acidified water on rainbow trout, Salmo gairdneri, olfactory organ were examined using scanning electron microscopy and electrophysiology. Exposure to pH 4.7 resulted in an increase in the number of mucus droplets over parts of the olfactory epithelium, primarily along the ridges of the secondary folds. The addition of aluminum (5.0, 9.5, 20.0 µmol · 1−1) at pH 4.7 resulted in loss of receptor cell cilia, irregularly shaped olfactory knobs, clumped microvilli and swellings on microridge cells. Electrical responses recorded from the olfactory nerve in response to the amino acid L-serine were similar to controls in fish exposed to acidified water. When fish were exposed to acidified water and aluminum the response was depressed. These morphological and electrophysiological changes could be used to indicate metal-induced stress in fish from natural ecosystems.
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  • 31
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    Research in experimental medicine 188 (1988), S. 411-423 
    ISSN: 1433-8580
    Keywords: Human fetal lung cell cultures ; Lamellar bodies ; Pneumocytes type II ; Intralipid ; Hydrocortisone ; Ultrastructure ; Morphometric analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Organotypic cell culture systems of human fetal lungs of 15, 18, and 26 weeks' gestational age were treated with Intralipid, a phosphatidylcholine-containing lipid mixture, and with hydrocortisone of varying concentrations. The lamellar bodies found in the pneumocytes type II were ultrastructurally identified. Their amount was quantitated by point-counting, a morphometrical method. Intralipid had a stimulating effect upon the surfactant production depending on the concentration admitted. This effect was quantitatively compared to the known effect of hydrocortisone. Intralipid at a concentration of 10−2% produced a significant increase of the relative volume of lamellar bodies (P = 0.05) at a gestational age of 18 weeks. This effect is comparable to hydrocortisone treatment at a concentration of 10−1% (P = 0.05) and 10−3% (P = 0.01). At a gestational age of 26 weeks, Intralipid at a concentration of 10−1% (P = 0.01) stimulated lamellar body production. Hydrocortisone had a similar effect at a concentration of 10−1% (P = 0.01). Intralipid does not pass the placenta-barrier and is locally applied by amniocentesis. Therefore, complications to the maternal organism and probably to the fetuses are negligible. The application of Intralipid represents an alternative method to accelerate antenatal surfactant production and to improve the rate of survival of preterm infants.
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  • 32
    ISSN: 1615-6102
    Keywords: Heat shock ; Soybean root ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Soybean seedlings (Glycine max) were incubated in narrow temperature regimes to study the effects of heat shock on cell structures. The incubation temperatures used were as follows: 1. 28 °C (2h); 2. 40 °C (2h); 3. 45 °C (2h); 4. 40 °C (2h)→45 °C (2h); 5. 47. 5 °C (10 min); 6. 40 °C (2h)→47. 5 °C (10 min). Both optical and electron micrographs were taken of the different tissues of root meristems as they responded to heat shock. Cells of roots heated to 45 °C (2h) or 47.5 °C (10 min) with lethal treatment showed drastic heat injuries:e.g., membrane damage, coagulated plasmolysis, protoplasmic contraction, and leakage of cell content. Nucleolar segregation occurred in cells treated at both lethal and supraoptimal temperatures. Seedlings preincubated at 40 °C (2 h) became thermo-tolerant to lethal temperature treatment of 45 °C (2 h) or 47.5 °C (10 min), by protecting the plasmalemma, mitochondria, plastids and nuclei from heat damage. Without preincubation, however, these structures were destroyed.
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  • 33
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    Protoplasma 147 (1988), S. 55-63 
    ISSN: 1615-6102
    Keywords: Generative cell ; Sperm cell ; Treetomato ; Ultrastructure ; Vegetative nucleus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The structure of the generative cell and its association with the vegetative nucleus in the pollen tube ofCyphomandra betacea Sendt. were observed with the electron microscope. The generative cell, bounded by its own plasma membrane and the inner plasma membrane of the vegetative cell, possesses the cytoplasmic extension which lies within the embayments of a vegetative nucleus. The generative cell contains the normal complement of organelles and, especially, microtubules which cluster into several groups adjacent to the plasma membrane, oriented along the longitudinal axis of the cell. In the pollen tube reaching the lower end of the style aftersemivivo pollination, both of the sperm cells are elongated and polyribosomes and microtubules are the outstanding feature in the cytoplasm. The two sperm cells are connected by a common transverse cell wall, while cytoplasmic channels exist in both the periplasm of the two sperm cells and the transverse wall. The leading sperm cell (Svn) is closely associated with the vegetative nucleus. Thus the present study demonstrates the existence of the male germ unit in the pollen tube ofC. betacea. The possible cytoplasmic continuity between the sperm cells and between the gametes and vegetative cell is considered.
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  • 34
    ISSN: 1432-0878
    Keywords: Ovary ; Steroid-secreting cells ; Ultrastructure ; Chorionic gonadotropin ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural characteristics of the ovarian medulla of the newly hatched white leghorn chick were studied in control animals and compared with chicks that were treated with human chorionic gonadotropin during embryonic development. The ovarian medulla was mainly occupied by epithelial cells which formed cords or islets surrounded by a basal lamina. Within this epithelial compartment, steroidogenic cells, poorly differentiated cells and a lacunary system could be recognized. When chicks were treated with human chorionic gonadotropin, steroidogenic cells became discernible; there was an increment in the amount of cytoplasm and the area of mitochondria. Poorly differentiated cells exhibited signs of stimulation, and transitional images suggested the transformation of these cells into steroidogenic cells. The epithelial cells of the lacunar system also displayed stimulated cytoplasmic organelles. Evidence was supplied suggesting that relatively undifferentiated cells persist in the ovarian medulla until hatching and can develop into steroidogenic cells under gonadotropic stimulation.
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  • 35
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    Cell & tissue research 251 (1988), S. 243-248 
    ISSN: 1432-0878
    Keywords: Thoracic duct ; Smooth muscle cell ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The three-dimensional cytoarchitecture and ultrastructure of the smooth muscle cells in the wall of the rat thoracic duct were investigated by scanning and transmission electron microscopy. The muscle layer basically consists of a single layer of circularly arranged cells. The smooth muscle cell is fusiform or ribbon-like in shape, as in veins or venules with a similar or smaller diameter. Connections by spinous processes are observed between adjacent muscle cells along their length. Spot-like membrane contacts frequently occur in areas where facing membranes are closely apposed. These are thought to be gap junctions and may be responsible for electrical coupling and mechanical attachment. Large invaginations arranged regularly in rows on the surface of the smooth muscle cells can be observed. These invaginations are closely associated with a flattened sarcoplasmic reticulum, and caveolae tend to open into the invaginations.
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  • 36
    ISSN: 1432-0878
    Keywords: Smooth muscle ; Intermediate filaments ; Dual network ; Ultrastructure ; Ascidian ; Halocynthia roretzi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An extensive network of intermediate filaments that interconnected cytoplasmic dense bodies and connected the dense bodies to the cell surface was revealed in double-fixed, tannic acid-stained preparations of ascidian smooth muscle. The filament network ran through spaces in the continuous network of myofibrils, connecting them longitudinally, obliquely and transversely to form an intimately associated, dual network. In their transverse passage, the intermediate filaments ran across myofibrils along I-zones exclusively, interconnecting successive dense bodies. The pattern of attachment of intermediate filaments to dense bodies was predominantly “one-sided.” The filaments, which themselves were not incorporated into the contractile apparatus, remained folded or unfolded between myofibrils and between sarcomere-like structures in synchrony with the contraction-relaxation cycles. These results suggest that the intermediate filaments mechanically maintain the organization and arrangement of myofibrils via an intimate association with the myofibrils in the regions of the dense bodies, in such a way that the filaments do not impede muscle function. Based on these observations, a new model for the network of intermediate filaments in smooth muscle cells is proposed.
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    Cell & tissue research 253 (1988), S. 137-143 
    ISSN: 1432-0878
    Keywords: Endostyle ; Ultrastructure ; Immunocytochemistry ; 5-Hydroxytryptamine ; Granules ; Ciona intestinalis ; Corella parallelogramma, (Tunicata) ; Ascidia mentula (Tunicata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cellular and subcellular distribution of serotonin (5-hydroxytryptamine, 5-HT) in the endostyle of three species of ascidians, Ciona intestinalis, Corella parallelogramma, Ascidia mentula, was studied by light-(immunoperoxidase) and electron-microscopic (immunogold) immunocytochemistry. At the light-microscopic level 5-HT-like immunoreactivity (5-HT-LI) was exclusively found in cells located in the lateral portion of the endostyle, between zone 7, known to have iodinating capacity, and zone 8, which consists of ciliated cells. At the electron-microscopic level, the 5-HT-immunoreactive cells were found to correspond to cells containing polymorphous, dense granules, 100–300 nm in diameter. The granules were located in the supranuclear cytoplasm facing the endostyle lumen as well as in the infranuclear cytoplasm facing the extracellular space. Quantification showed that the 5-HT-LI was considerably higher (13–67 times) in cytoplasmic areas containing granules as compared to areas devoid of granules. Most, but not all, of the 5-HT-LI was associated with the dense core of the granules. In conclusion, serotonin-containing cells are located in the peripheral portion of the endostyle, between zones 7 and 8. Serotonin is stored in cytoplasmic granules that are present both in the apical and basal cytoplasm. This suggests the possibility that the cells are bipolar and secrete serotonin both in a basal direction to the extracellular space, and in an apical direction to the pharyngeal lumen.
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  • 38
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    Cell & tissue research 251 (1988), S. 87-93 
    ISSN: 1432-0878
    Keywords: Paneth cells ; Ultrastructure ; Morphometry ; Facultative anaerobes ; Germ-free mice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Germ-free mice were given live or heat-killed facultative anaerobes, and the ultrastructure of ileal Paneth cells was quantitatively examined with special reference to secretory granules showing a bipartite substructure (central core and peripheral halo). After administering live or heatkilled bacteria, there was a decrease in the area occupied by the cores of secretory granules in Paneth cells, and exocytosed core material was observed in the crypt lumen. There were no changes in the area occupied by the halo of secretory granules. None of the examined Paneth cells phagocytosed bacteria. It is concluded that certain bacteria may affect the secretion of antibacterial agents contained in the secretory granules of Paneth cells.
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  • 39
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    European journal of applied physiology 57 (1988), S. 360-368 
    ISSN: 1439-6327
    Keywords: Humans ; Skeletal muscles ; Anaerobic exercise ; Histocytochemistry ; Ultrastructure ; Muscle cell injury
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The vastus lateralis muscles of eleven male elite sprinters (17–28 years) were investigated in order to examine the impact of high tension anaerobic muscular work on muscle fibre fine structure. In an attempt to reproduce the training regimen six subjects ran 20 repetitions of 25 s on a treadmill with 2 min 35 s in between, at a speed corresponding to 86% of their personal best 200 m time. PAS-stained sections of biopsies taken approximately 2 h after training generally indicated glycogen depletion in type 1 and type 2B fibres. At the light microscopic level, no signs of inflammation or fibre rupture were observed. However, at the ultrastructural level, frequent abnormalities of the contractile material and the cytoplasmic organelles were detected. Z-band streaming, autophagic vacuoles and abnormal mitochondria were the most conspicuous observations. Control specimens from sprinters who did not perform the acute exercise routine also displayed structural deviations, although to a lesser degree. It is hypothesized that during sprint training the leg musculature is put under great mechanical and metabolic stress which causes the degenerative response reported here.
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  • 40
    ISSN: 1615-6102
    Keywords: Cytoskeleton ; Plasma membrane ; Microtubules ; Ultrastructure ; Freeze-fracture ; Flagellates ; Proteromonas lacertae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The anterior half of the cell surface of the parasitic flagellateProteromonas lacertae is corrugated while the posterior half is covered by hair-like appendages, called somatonemes. In the anterior part, the cortical microtubules are lined by a zig-zag shaped microfibril. Here, these two structures seem to be separated from the plasma membrane. In the posterior half of the cell the somatonemes, analogous to the mastigonemes of chrysophytes, are anchored to the cortical microtubules by paired small deposits of dense material. This was clearly demonstrated by Triton X 100 treatment which solubilized the plasma membrane but left the somatonemes attached to the cortical microtubules. Freeze-fracture images revealed the alignment of clustered intramembrane particles on the P-face of the plasma membrane which correspond to the attachment sites of the somatonemes, seen as dots in thin sections. The ER-derived membrane-associated somatonemes are probably linked to the cortical microtubules by anchoring proteins which are part of the plasma membrane.
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  • 41
    ISSN: 1615-6102
    Keywords: Aphanochaete ; Astral microtubules ; Immunofluorescence ; Phycoplast ; Spindle breakdown ; 3-D reconstruction ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The spatial and temporal organization of the microtubular cytoskeleton at the transitional stage of mitosis and cytokinesis has been studied in the chaetophoralean green algaAphanochaete magna using indirect immunofluorescence light microscopy and transmission electron microscopic analysis of serial sections including computer-aided three-dimensional reconstruction. At late mitosis, elaborate asterlike microtubule systems including bundles interconnecting both centriolar regions are present. These systems disappear a the onset of interzonal spindle disintegration. The incipient phycoplast consists of a star-shaped microtubule assemblage projecting from the intact interzonal spindle. It develops strongly at the time of spindle disintegration, later on it becomes compressed by daughter nuclei movement. Cell plate formation is associated with a two-dimensional phycoplast. Phycoplast microtubules remain for a while associated with the completed cross wall but finally they depolymerize. The general occurrence of astral microtubule systems (includingA. magna) is evaluated. The subsequent developmental stages of the phycoplast, formation, maturation and depolymerization, are discussed.
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  • 42
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    Protoplasma 146 (1988), S. 166-173 
    ISSN: 1615-6102
    Keywords: Entomophthorales ; Entomophthora muscae ; Ultrastructure ; Cytochemistry ; Protoplast ; in vitro growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Entomophthora muscae (C.) Fres. can be grownin vitro as protoplasts. Light and electron microscopical studies of thein vitro developed protoplasts have demonstrated the absence of an organized wall over the protoplasmic Con A-positive membrane at all stages of growth. The cytological organization is typical of the Entomophthorales with condensed chromatin in the interphase nuclei and small eccentric metaphase spindles. Long strands of endoplasmic reticulum, microubules and vesicles surrounding the plasmalemma may be involved in maintaining the precise shape ofE. muscae protoplast. Starvation of the fungus induces the formation of hyphal bodies after deposition of Con A- and WGA-positive wall material at the plasmalemma surface.
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  • 43
    ISSN: 1615-2573
    Keywords: l-Propionylcarnitine ; Amphiphile ; Action potential ; Ultrastructure ; Guinea pig ventricular muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We examined the effects ofl-propionyl-carnitine (Prop.C), a short-chain acylcarnitine, on amphiphile (l-lysophosphatidylcholine orl-palmitoylcarnitine)-induced electrophysiological and ultrastructural changes in isolated guinea pig ventricular papillary muscles, under acidic conditions (pH 6.9). Conventional microelectrode, tension-recording, and electron microscope techniques were used. Both amphiphiles, at a concentration of 10−4 M, significantly decreased the resting membrane potential, action potential amplitude, and action potential duration, but increased the developed and resting tension. Such amphiphile-induced electrical changes were not observed in muscles pretreated with the beta-blocker, atenolol, although the mechanical changes remained unaffected. The application of Prop.C (10−2 M), in the continued presence of the amphiphiles caused a return of the action potential duration and the developed tension to the control level. However, the resting potential and action potential amplitude remained unaffected; in fact, the maximum upstroke velocity ( $$\dot V_{max} $$ ) of the action potential tended to decrease further. Pretreatment with Prop.C prevented all the amphiphile-induced electrophysiological and mechanical changes, except for $$\dot V_{max} $$ . Electron microscopic studies revealed that amphiphile-induced ultrastructural changes were prevented, at least in part, in the presence of Prop.C. Thus, Prop.C antagonizes some of deleterious effects of amphiphiles, such as lysophosphatidylcholine and palmitoylcarnitine, upon the electrical and mechanical activities of the ventricular muscle, under acidic conditions.
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  • 44
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    Protoplasma 146 (1988), S. 65-71 
    ISSN: 1615-6102
    Keywords: Apiaceae ; Eryngium campestre ; Metabolism ; Pollen grain ; P-particle ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The metabolism of P-particles (polysaccharide particles) was investigated in mature pollen grains ofEryngium campestre L. Numerous P-particles, originating from dictyosome activity, are found to be accumulated near the apertures, followed by mitochondria. A single layer of ER profiles seems to prevent the fusion of the P-particles with the intine. Instead of this, they fuse with each other forming nonmembrane-bounded polysaccharide-aggregates, which subsequently change their granulated structure to an amorphous. Mitochondria together with small vesicles are involved in the conversion-process. The so formed wall precursors pass through the ER and fuse into the intine.
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  • 45
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    Protoplasma 146 (1988), S. 143-149 
    ISSN: 1615-6102
    Keywords: Hyphal tip ; Ultrastructure ; Freeze substitution ; Sclerotium rolfsii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The hyphal tip ofSclerotium rolfsii was examined after fixation by freeze substitution. The Spitzenkörper consisted of a dense mass of apical vesicles and microvesicles surrounding a vesicle-free zone. Linear arrangements of microvesicles were occasionally observed within the Spitzenkörper. Abundant microfilaments were seen within the Spitzenkörper region, often in close association with apical vesicles and microvesicles. Microtubules passed through the Spitzenkörper and terminated at the plasmalemma at the extreme hyphal apex. Filasomes were mostly observed within the apical region and were in close proximity to the plasmalemma. Rough ER, mitochondria, microtubules, and vacuoles were abundant in the subapical region and were usually oriented parallel to the long axis of the hypha. Ribosomes were aligned on the outer surfaces of mitochondria. Golgi body equivalents were observed throughout the subapical region and appeared as inflated cisternae of varying shapes and electron opacities. Relationships to other basidiomycetous hyphal tip cells are discussed.
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  • 46
    ISSN: 1432-0878
    Keywords: Endothelium ; Swim bladder ; Capillaries ; Vesicles ; Ultrastructure ; Cryofixation ; Anguilla rostrata (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Several recent studies comparing chemically fixed and cryofixed endothelium have indicated that glutaraldehyde fixation may result in increases in the population of “vesicles” in the cytoplasm. Other reports based on ultrathin serial-section reconstruction of chemically fixed endothelium have revealed that the vesicular system is comprised of interconnected membranous compartments, which are ultimately continuous with either cell surface but do not extend across the endothelial cell. In this study, we have investigated the three-dimensional organization of the vesicular system in directly frozen, freeze-substituted capillaries of the rete mirabile from the swim bladder of the eel, specifically using the same block of embedded capillaries in which frozen capillaries had previously been found to contain less “vesicles” than chemically fixed capillaries. The results show that essentially all vesicles remain inter-connected with each other and are part of two separate sets of invaginations from the luminal and abluminal cell surface like in chemically fixed tissue. Any increase in vesicle number resulting from glutaraldehyde fixation does not affect the overall three-dimensional organization of the vesicular system in these endothelial cells.
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  • 47
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    Cell & tissue research 251 (1988), S. 189-195 
    ISSN: 1432-0878
    Keywords: Lymphocytes ; Epithelium ; Mast cells ; Granular leukocytes ; Basophils ; Ultrastructure ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Examination, by light and electron microscopy, of the morphology and the staining properties of intraepithelial lymphocytes from the intestine of the chicken revealed a population of lymphoid cells, of which a proportion (up to 20%) is granulated. The majority of cells were immunoreactive with anti-T cell serum and can therefore be considered to be related to T-lymphocytes, but they did not proliferate when cultured with phytohaemagglutinin. The granulated cells were identical to those previously designated globule-containing leukocytes, but were distinct from mast cells in their morphology, staining reactions and the stability of the granules in different fixatives and buffers.
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    Cell & tissue research 251 (1988), S. 205-214 
    ISSN: 1432-0878
    Keywords: Kupffer cells ; Granulocytes ; Ultrastructure ; Lipopolysaccharide ; Liver ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of Kupffer cells has been studied at various times after an intravenous injection of lipopolysaccharide of Salmonella abortus equii. The most prominent effects were: an increase in the number and dimensions of phagocytic vacuoles (often containing ingested LPS and neutrophilic granulocytes); mitochondrial damage, including disintegration of the matrix and cristae; an increase in the amount of dilated, lucent rough endoplasmic reticulum; presence of fat droplets in the cytoplasm. Five days after injection of lipopolysaccharide, the Kupffer cells had resumed their normal ultrastructure. Several minutes after injection of lipopolysaccharide, platelets adhered to the Kupffer and endothelial cells. Between one and six hours, neutrophilic granulocytes accumulated in the liver sinusoids. The resulting obstruction of the hepatic microcirculation most probably affected cellular ultrastructure by ischaemia. At three days, the number of Kupffer cells was doubled, and increased further at later time intervals.
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  • 49
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    Cell & tissue research 252 (1988), S. 581-587 
    ISSN: 1432-0878
    Keywords: Normal resting breast ; Ultrastructure ; Mitosis ; Cytokinesis ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The parenchyma of the normal “resting” human breast was examined by electron microscopy to characterize the cells undergoing mitosis and the mechanism by which the normal tissue architecture is maintained during this process. In this study of 112 mitotic cells, it was found that the mitotic cells were luminally positioned, polarised epithelial cells with no evidence of myoepithelial cell division. Ultrastructurally, the nuclear and cytoplasmic changes were consistent with previous reports of mitosis in other tissues. However, unlike all previous reports, two specific orientations of the nuclear spindle and thus the planes of cytokinesis were observed. In a few cases the spindle formed parallel to the lumen and division resulted in two luminally positioned daughter cells. However, in the majority of mitotic cells the spindle was approximately at right angles to the lumen and this orientation resulted in a luminally and a basally positioned daughter cell. It is proposed that the abnormally positioned basal daughter cell could develop into a myoepithelial cell or undergo deletion (apoptosis). Thus the two orientations of mitosis may explain the mechanism by which the epithelial and myoepithelial cell populations were maintained by a single progenitor cell without disrupting the integrity of the tissue architecture.
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  • 50
    ISSN: 1432-0878
    Keywords: Chromatophores ; Color change ; Ultrastructure ; Melanophores ; Macrophages ; Xanthophores ; Cichlasoma citrinellum (Teleostei: Cichlidae)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary We describe the histological basis of color metamorphosis in the polychromatic Midas cichlid, Cichlasoma citrinellum. Eight percent of the individuals in a natural population transform from gray with black markings to orange, simultaneously losing their ability to adjust coloration in response to background and social context. This trait is inherited. Light- and electron microscopy revealed that this transformation is a two-step process. First, the melanophores die, then macrophage-like cells remove the debris. As a result of this initial process, the underlying xanthophores become visible, producing the orange coloration. A similar process may occur in individuals that further transform to white, or go directly from gray to white.
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  • 51
    ISSN: 1432-0878
    Keywords: X-organ ; Sinus gland ; Ultrastructure ; Cyclic activity ; Siriella armata (Crustacea)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the medulla interna-medulla externa X-organ (MI-ME Xo)-sinus gland (SG) complex in the eyestalk of Siriella armata is described during the normal and the experimentally inhibited molt cycle. In the normal SG, four types of neurosecretory axon terminals, each containing distinguishable neurosecretory granules, can be described. Thus, type-2 granules are synthesized by G1 neurons forming the MI-ME Xo. The cell bodies and axonal endings of these cells in the sinus gland have been examined at the following molt stages: intermolt (stage C4), premolt (D0 and D2), and postmolt (A1, A2 and B). Changes in ultrastructure of the G1 cells have been monitored and correlated to inhibitions of the molt-and reproductive cycle produced by electrocauterization of the MI-ME Xo. The results obtained suggest that the neurosecretion from the G1 cells exerts a positive influence on molt and brood preparation. The occurrence of a distal group of G1 cells whose axons terminate at a different site from the SG suggests that the neural factors of the MI-ME Xo are diverse and control different physiological activities.
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  • 52
    ISSN: 1433-0350
    Keywords: Malignant astrocytoma ; Glioblastoma ; Cerebellum ; Children ; Cytofluorometric DNA analysis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The case of a 1-year-old girl with primary malignant astrocytoma of the cerebellum is presented with special reference to ultramicroscopic study and cytofluorometric DNA analysis. The routine light microscopic study was not pathognomonic because of the immaturity of the composing cells. The glial fibrillary microfilaments characteristic of astroglial cells were confirmed by means of electron microscopy. Cytofluorometrically, the DNA histogram of this case revealed a prominent peak in the 4C region, with considerable dispersion to the 8C region, indicating the polyploidic and heterogeneic pattern of malignant tumors.
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  • 53
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    European archives of oto-rhino-laryngology and head & neck 244 (1988), S. 360-362 
    ISSN: 1434-4726
    Keywords: Nasal mucosa ; Kartagener's syndrome ; Ciliated mucous cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Transmission electron microscopy revealed the presence of ciliated cells containing many mucous secretory granules in the nasal surface epithelium of a 13-year-old patient suffering from Kartagener's syndrome. In these cells, mucous secretory granules were accumulated in the apical cytoplasm, and the Golgi apparatus was well developed in the supranuclear region. Mucous secretory granules were discharged infrequently through the apical cell membranes by single or compound exocytosis. The cells were considered to be ciliated mucous cells, which have already been reported to be present in the lower respiratory tract but not in the upper respiratory tract.
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  • 54
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    European archives of oto-rhino-laryngology and head & neck 245 (1988), S. 145-150 
    ISSN: 1434-4726
    Keywords: Salivary gland tumor ; Adenocarcinoma ; Ultrastructure ; Signet-ring cell ; Intracytoplasmic lumen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A histological and subcellular study of a mucus-producing adenopapillary carcinoma of a minor salivary gland is presented. The tumor was located on the buccal mucosa of a 36-year-old white man. Microscopic examination showed that the tumor was an invasive papillary growth with numerous signet-ring cells and mucous production. When viewed under the electron microscope, the tumor exhibited clusters of cells showing intracellular lumina and finely dispersed chromatin.
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  • 55
    ISSN: 1432-0878
    Keywords: Tentacles ; Ultrastructure ; Adhesion ; Leptosynapta spp (Holotheorie) ; Echinodermata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The tentacles of the apodous holothurian Genus Leptosynapta have been studied by use of transmission and scanning electron microscopy. The gross anatomy, water vascular system, fibre systems and ectoneural nerve ring are described. A fuzzy coat of attenuated filaments covers the surface of the tentacle, broken only by secretory ducts. A cuticle underlies the fuzzy coat. Bacteria are common in the subcuticular space. Fixation without osmium gives poor preservation of the surface coats. The epidermis consists of a single layer of columnar cells consisting of Type-1, Type-2, support, goblet and uniciliated cells. Type-1 cells secrete electron-dense material and appear to be homologous to adhesive cells of the tentacles of other holothurians. The support cells contain large, granular vesicles not found in other holothurians. Goblet cells contain flocculent mucus and have an apical cilium. Goblet cells are not found in other holothurian tentacles and may function to lubricate and wrap adhering particles to aid their ingestion. The uniciliated cells are rare, poorly developed and the cilium does not extend past the cuticle. The ultrastructure of the tentacles is discussed in relation to those of other holothurians.
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  • 56
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    Cell & tissue research 252 (1988), S. 123-132 
    ISSN: 1432-0878
    Keywords: Uterine epithelium ; Cell culture ; Proteins ; Ultrastructure ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Morphological and biochemical changes occurring in rabbit endometrial epithelial cells when placed in culture were investigated. Cells were examined by scanning- and transmission electron microscopy and freeze-fracture. Morphologically, cultured cells are shorter and broader than the columnar epithelial cells in vivo, but retain their polarity as indicated by the presence of apical microvilli and a well-developed junctional belt. To study changes in biochemical function, proteins synthesized by cells in primary culture were analyzed by two-dimensional gel electrophoresis. Proteins were labeled during a 24-h incubation with 35S-methionine and gels examined by fluorography. The pattern of proteins changed after cells had been in culture for 48 h. On day 3 new proteins were synthesized and several protein species labeled during days 1 or 2 of culture, including uteroglobin, no longer appeared. On days 3–8 of culture the protein patterns were similar. Addition of progesterone, estradiol, prolactin, or combinations of these hormones to the culture medium for 24–144 h failed to elicit consistent changes in the pattern of labeled proteins established after 3 days of culture. Minor differences in protein patterns among unrelated cultures appear to have been derived from the original cells of the culture. These results indicate that after 48 h in primary culture, cells grown in vitro resemble endometrial epithelial cells morphologically, but no longer reflect functionally the character of epithelial cells in the uterus.
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  • 57
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    Cell & tissue research 252 (1988), S. 157-163 
    ISSN: 1432-0878
    Keywords: Frog skin culture ; Desmogenesis ; Interdigitations ; Lamellipodia ; Ultrastructure ; Rana esculenta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Small trypsinized explants from ventral skin of frogs (Rana esculenta) were maintained in culture for 4 days during which a newly formed epithelium differentiated along the cut edges of the dermis. During the first 6 h adjacent cells produced numerous interdigitating lamellipodia. After 2 days, epithelial polarity was restored by the formation of zonulae occludentes and the epithelial cells were joined by a few small newly formed desmosomes and by numerous interdigitations. Bipartite junctional complexes consisting of a zonula occludens, followed by a series of typical desmosomes, and characteristic of adult frog epidermis were formed only after 4 days. When cultured in the presence of an inhibitor of protein synthesis (cycloheximide) the trypsinized epidermis no longer formed desmosomes. Therefore pools of one or more crucial desmosomal proteins must be very low or non-existent. However, cycloheximide did not prevent the formation of cell contact specializations, consisting of a highly developed system of complex lamellar interdigitations, between adjacent cells.
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  • 58
    ISSN: 1432-0878
    Keywords: Lung ; Ultrastructure ; Marsupial ; Newborn ; Surfactant ; Dasyurus hallucatus, Trichosurus vulpecula
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The lungs of newborn northern native cats, Dasyurus hallucatus and newborn brushtail possums, Trichosurus vulpecula were examined by both light and electron microscopy. The native cat has a birth weight of 18 mg after a gestation of about 21 days, whereas the brushtail possum weights 200 mg at birth and has a gestation period of 17.5 days. The lungs of the native cat are two large respiratory sacs, with a respiratory lining of squamous cells and surfactant-secreting cells. The capillaries are located within the connective tissue just below this respiratory epithelium. The visceral covering of the lung is formed by squamous cells. The lungs of the possum are composed of numerous large respiratory sacs which are separated by connective tissue septa in which the capillaries are located. The sacs, as in other species, are lined with squamous cells and surfactant secreting cells. It is proposed that the structure of the lung of the newborn marsupial is related more to the size of the newborn rather than to the length of the gestation period.
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  • 59
    ISSN: 1432-0878
    Keywords: Basement membrane ; Lipids ; Ultrastructure ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Developing rat incisors were treated with malachite green-aldehyde fixative solution (MGA), which retains and stains lipids. We observed positive staining occurring as dots in the basement membrane. Most of these dots (2–3.5 nm in diameter) were grouped in the lamina densa but some were also present in the lamina lucida and the lamina fibroreticularis. These data provide evidence for the existence of lipids in the dental basement membrane and suggest that they are distributed together with the various groups of proteins so far detected.
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  • 60
    ISSN: 1432-0878
    Keywords: Adrenergic nerves ; Steroidogenic cells ; Embryonic ovary ; β 2Adrenoceptors ; Cytochemistry ; Ultrastructure ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present study investigates the innervation of the embryonic chick ovary with regard to (i) development and compartmentalization of catecholaminergic nerves, and (ii) presence of adrenoceptors on steroidogenic target cells of catecholaminergic nerve terminals. Catecholaminergic nerve fibers visualized by glyoxylic acid-induced histofluorescence first appeared at embryonic day (E) 13. From E15 through E21 the density of fluorescent aminergic nerves increased markedly in parallel with the concentration of catecholamines and numbers of nerve bundles and single axons seen at the electron-microscopic level. Catecholaminergic nerves were confined to the ovarian medulla and closely associated with interstitial cells. Nerve terminals approached interstitial cells up to a distance of 20 nm and, in their majority, exhibited uptake of the false adrenergic transmitter 5-hydroxydopamine. Although adrenaline amounted to 14% of the total catecholamine content at E21, adrenaline immunoreactivity was only detected in adrenal chromaffin cells, but not in nerve fibers or cell bodies within the ovary. Interstitial cells structurally matured between E15 and E21 as documented by an increase of smooth endoplasmic reticulum and tubular mitochondria. Monoclonal antibodies mAB 120 and BRK 2 raised against avian β 1 and mammalian β 2-adrenergic receptors revealed the presence of β 2-adrenoceptor-like immunoreactivity on the surface of interstitial cells, but not on any other cell type. The results are consistent with the notion of a dense adrenergic innervation of the embryonic chick ovarian medulla and its steroidogenic interstitial cells, and suggest the chick ovary as an excellent model for elucidating the functional role of a neural input to steroidogenic cells during development.
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  • 61
    ISSN: 1432-0878
    Keywords: Neuropeptide Y (NPY) ; Penis erection ; Perivascular nerve fibers immunocytochemistry ; Ultrastructure ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neuropeptide Y 1–36 (IR-NPY) immunoreactive nerve-fiber processes have been observed in tunicae of veins and arteries and in smooth muscles of the human penis taken at autopsy or during surgery by use of light-and electron-microscopic immunohistochemical techniques. Numerous IR-NPY nerve fibers were mostly concentrated in the inner part of the adventitia close to the media of the arterial and venous vessels and among the intracavernous smooth muscle cells. IR-NPY nerve fibers were less abundant in veins than in arteries. Positive somata were not observed in the penises. At the ultrastructural level, IR-NPY were localized exclusively in large, dense granules of nerve terminals by means of the postembedding immunogold technique. In the deep dorsal vein, IR-NPY nerve fibers were also located in the media formed by an outer circular and an inner longitudinal layer. In the intracavernous and dorsal arteries, they showed the highest density in the inner part of the adventitia. In the corpora cavernosa and in the corpus spongiosum, IR-NPY nerve processes were intermingled between the smooth-muscle fibers around the sinusoid spaces. IR-NPY nerve fibers were present in the cavernous nerves close to the central arteries. The urethra did not show any IR-NPY-positive nerve fibers. This peculiar distribution of IR-NPY nerve fibers suggested that they could participate in regulating arterial and venous blood flow and intracavernous smooth-muscle tone. NPY may therefore be of importance in some of the mechanisms of penile erection especially during detumescence.
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  • 62
    ISSN: 1432-0878
    Keywords: Thymus ; Cultured thymic fragments ; Epithelial cells ; Microenvironment ; Ultrastructure ; Rat (nude)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cultured thymic fragments correspond to the thymic microenvironment depleted of lymphocytes and dendritic cells. When these fragments are implanted under the kidney capsule of congenitally athymic rats, lymphocytes and dendritic cells of host origin enter the graft and induce thymus-dependent immunity in the recipient. This paper describes the ultrastructure of the fragments and the changes that occur during the restoration of normal thymic architecture. At the end of the culture period of 6–9 days and in the early stages after implantation, the grafts consist of keratin-containing epithelial cells of unusual morphology that can be labelled with antibodies raised against the epithelium of the mid/deep cortex and the subcapsule/medulla. Normal thymic architecture develops, including nerves and blood vessels, as lymphocytes populate the environment, and by 4–6 weeks the epithelial cells are the same phenotypically and ultrastructurally as those found in normal rat thymus. However, some areas without lymphocytes still contain the atypical epithelial cells seen before implantation. Large multinucleated giant cells are also present with a few associated epithelial cells of subcapsular/medullary phenotype. In conclusion, the cultured thymic fragments contain a hitherto unknown precursor epithelial cell with an atypical ultrastructure and phenotype that is not seen in normal development.
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  • 63
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    Cell & tissue research 253 (1988), S. 397-402 
    ISSN: 1432-0878
    Keywords: Paneth cells ; Ultrastructure ; Morphometry ; Atropine ; Germ-free/Ex-germ-free ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Previous studies have shown that the secretory products of Paneth cells contain antibacterial agents (lysozyme, IgA) that are affected by the bacterial milieu in the intestine. To investigate whether Paneth-cell secretion is controlled via cholinergic mechanisms, the ultrastructure of Paneth cells was studied in four animal groups: (1) germfree (GF) control mice (Jcl: ICR [GN], male, 13 weeks old), (2) GF mice injected subcutaneously with atropine sulfate (200 mg/kg body weight, dissolved in physiological saline 20 mg/ml), (3) ex-GF mice inoculated with feces from specific-pathogen-free (SPF) mice, and (4) ex-GF mice injected with atropine and inoculated with feces from SPF mice. In ex-GF mice inoculated with feces, 70–90% of the Paneth cells showed fewer secretory granules than those from GF mice (p〈0.01). Approximately 30% of the Paneth cells had a large vacuole (3–10 μm diameter) in the apical cytoplasm. Exocytosed electron-dense material from secretory granules was observed in a few crypt lumens. In ex-GF mice inoculated with feces and given atropine, about 90% of the Paneth cells contained numerous secretory granules, like those in GF control mice, but vacuolated Paneth cells and exocytotic figures were rare; thus the secretion of Paneth cells was blocked by atropine. It is therefore possible that the bacterial milieu in the intestine affects the secretory activity of Paneth cells via cholinergic mechanisms.
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  • 64
    ISSN: 1432-0878
    Keywords: Implantation ; Embryo ; Ultrastructure ; Vasculature ; Rat (Sprague-Dawley) ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Preimplantation-stage embryos were transferred to the anterior eye chamber of recipient rats and guinea-pigs. After implantation had occurred the influence of the embryo on the iris vasculature was examined ultrastructurally. In both species, the earliest effect of embryonic implantation was an increased stromal oedema. Under increasing embryonic influence the vascular endothelial cells showed an increased number of projections into the vascular lumen, while in the rat, endothelial projections were also found pushing back into the basement membrane. In the rat, the endothelium became very irregular in thickness prior to complete disintegration and loss during more advanced stages of implantation. Rat embryonic trophoblast was found invading iris vasculature, particularly in areas where the iridial endothelium was partially or completely missing. Other cells in the iris, including the stroma, appeared to be less affected. In the guinea-pig, however, trophoblast cells appeared to be capable of invading the vasculature by displacing endothelial cells that still appeared morphologically normal.
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  • 65
    ISSN: 1432-0878
    Keywords: Lateral-line sense organs ; Mechanoreceptors ; Supporting cells ; Ultrastructure ; Pleurodeles waltlii (Urodela)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural and histochemical features of the accessory cells of the neuromast of the salamander P. waltlii have been examined. Three types of accessory cells, supporting, mantle, and basal, were found, but only the first 2 are considered in this article. Supporting cells characterized by a highly dilated endoplasmic reticulum occur among and surrounding sensory cells. Mantle cells, morphologically different from the supporting cells, surround the remainder of the neuromast. Both types of accessory cells exhibit histochemically different secretory materials. Our morphological results suggest that both accessory cells contribute to the formation of cupular material.
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  • 66
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    Cell & tissue research 254 (1988), S. 247-249 
    ISSN: 1432-0878
    Keywords: Pinealocyte ; Light exposure ; Ultrastructure ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Although it is generally known that light strongly influences N-acetyltransferase activity and melatonin production in the pineal gland, little information is available concerning morphological changes following light exposure. As exposure of rats to a short light pulse at night rapidly depresses melatonin synthesis, we decided to determine whether this experimental condition produces rapid changes in the pinealocyte organelles. A 30-min light pulse at night (six hours after lights out) provoked rapid changes in the relative volumes of some pinealocyte organelles. The volume fractions of mitochondria, Golgi apparatus and lipid droplets, and the numbers of dense-core vesicles and “synaptic” ribbons decreased, whereas the volume fraction of lysosomes increased. There were no differences in the volumes of granular endoplasmic reticulum and vacuoles containing flocculent material in those animals exposed to light compared with control animals. These results indicate that a short light pulse at night causes ultrastructural changes that can be interpreted as morphological features of diminished activity of pinealocytes.
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  • 67
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 561 (1988), S. 139-148 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Concerning Alkali Metal Metaselenoarsenites. Preparation and Crystal structures of MAsSe2, M = K, Rb, CsThe metaselenoarsenites MAsSe2, M = K, Rb, Cs were prepared by methanolothermal reaction of M2CO3 with As2Se3 at a temperature of 130°C. Their X-ray structural analyses demonstrated that the compounds contain polymetaselenoarsenite anions [AsSe2-]∞, in which the basic units are ψ-AsSe3 tetrahedra, which are linked via shared corners into infinite chains. Vierer single chains are observed for KAsSe2 and RbAsSe2, zweier single chains for CsAsSe2. The stretching units s are respectively 3,157, 2.336 and 3,378 Å. The relationship between the conformation of metaselenoarsenite chains and cation size is discussed.
    Notes: Die Metaselenoarsenite MAsSe2, M = K, Rb, Cs wurden durch methanolothermale Reaktion von M2CO3 mit As2Se3 bei einer Temperatur von 130°C dargestellt. Ihre Röntgenstrukturanalysen ergaben, daß die Verbindungen Polymetaselenoarsenit-Anionen [AsSe2-]∞ beinhalten, in denen die Grundelemente ψ-AsSe3-Tetraeder sind, die über gemeinsame Ecken zu unendlichen Ketten verknüpft sind. Für KAsSe2 und RbAsSe2 werden Vierer-, für CsAsSe2 Zweier-Einfachketten gefunden. Die Streckungseinheiten s betragen 3,157, 2,336 bzw. 3,378 Å. Die Beziehung zwischen Konformation von Metaselenoarsenitketten und Kationgröße wird erläutert.
    Additional Material: 3 Ill.
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  • 68
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    Zeitschrift für anorganische Chemie 562 (1988), S. 102-104 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Untersuchungen an A4BX6-Verbindungen. II. Strukturverfeinerung von Rb4PbBr6 und eine Bemerkung zur Existenz von „Rb4HgI6“ und „K4CdI6“Rb4PbBr6 wurde in einer Festkörperreaktion aus den binären Komponenten präpariert und die Struktur mit Einkristalldaten verfeinert (a = 1332,9(4), c = 1647,8(5) pm, R.Gr. R3c; K4CdCl6-Typ). Rb4HgI6 und K4CdI6 ließen sich nicht darstellen. Diese Ergebnisse werden im Zusammenhang mit dem Strukturfelddiagramm für A4BX6 Verbindungen diskutiert.
    Notes: Rb4PbBr6 was prepared by solid state reaction of the binary compounds and the structure refined with single crystal data (a = 1332.9(4), c = 1647.8(5) pm; space group R3c; K4CdCl6-type arrangement). Attempts to synthesize Rb4HgI6 and K4CdI6 were unsuccessful. The results are discussed on the basis of a structure field diagram for A4BX6 compounds.
    Additional Material: 1 Tab.
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  • 69
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 562 (1988), S. 131-140 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structures of Pb5(GeO4)2SO4 and Pb5(GeO4)2CrO4, Two Lead Apatites with Vacant Halogen SitesPb5(GeO4)2SO4 (a = 1005.8; c = 741.6 pm) and Pb5(GeO4)2CrO4 (a = 1010.5; c = 742.8 pm) are hexagonal, space group P63/m, Z = 2 formula units. They crystallize with the apatite structure type. The halogen positions in the channels are not occupied. This pecularity is caused by the Pb2+ ions on the 6h positions. Their lone pairs of electrons are sterically active, being directed into the channels. The electron lone pairs of the Pb2+ ions of the 4f positions also show sterical effect.
    Notes: Pb5(GeO4)2SO4 (a = 1005,8; c = 741,6 pm) und Pb5(GeO4)2CrO4 (a = 1010,5; c = 742,8 pm) sind hexagonal, Raumgruppe P63/m, Z = 2 Formeleinheiten. Sie kristallisierten in der Apatitstruktur, wobei die Halogenlagen in den Kanälen nicht besetzt werden. Diese Besonderheit ist durch die Pb2+-Ionen auf der Lage 6h bedingt. Ihre freien Elektronenpaare sind stereochemisch wirksam und weisen in die Kanäle hinein. Auch bei den Pb2+-Ionen auf der Lage 4f ist ein stereochemischer Einfluß des freien Elektronenpaares erkennbar.
    Additional Material: 3 Ill.
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  • 70
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Untersuchungen an A4BX6-Verbindungen. III. ns2-Kationen als Bedingung für einen Strukturtyp und ihre Wechselwirkung in ternären Halogeniden vom Typ A4BX6 (A: In, Tl; B: Cd, Pb, Ge; X: Cl, Br, I)Wir diskutieren die Art der Wechselwirkung von Kationen mit ns2-Konfiguration in ternären Halogeniden des Formeltypes A4BX6 (A: In, Tl; B: Cd, Pb, Ge; X: Cl, Br, I), die im Tl4HgBr6-Typ kristallisieren. Wir berichten über Hochdruckexperimente 'an solchen A4BX6-Verbindungen und über röntgenographische Untersuchungen und Kristallstrukturverfeinerungen an Mischkristallen des Typs A′xA4-xBX6, in denen die ns2-Kationen teilweise durch solche mit Edelgaskonfiguration substituiert sind. Die Ergebnisse unserer Experimente zeigen, daß die ns2-Kationen diesen ungewöhnlichen Strukturtyp durch Polarisationseffekte stabilisieren und durch ihre größere Elektronegativität im Vergleich zu der von Alkaliionen von ähnlicher Größe.
    Notes: We discuss the interaction of ns2-type cations in ternary halides of the formula type A4BX6 (A: In, Tl; B: Cd, Pb, Ge; X: Cl, Br, I) crystallizing in a Tl4HgBr6-type arrangement. We report on high pressure experiments on such A4BX6 compounds and on x-ray studies and structure refinements of mixed crystals of the type A′xA4-xBX6, where cations A′ with a closed shell configuration partly substitute for the ns2-type A ions. The results of our experiments show, that ns2-type cations stabilize this unusual structure type by polarization effects and by their higher electronegativity as compared with alkali ions of comparable size.
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  • 71
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 562 (1988), S. 123-130 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ag2PdCl4, Crystal Structure and the Crystal Chemical Relation to the NaCl TypeAg2PdCl4 single crystals show orthorhombic symmetry with the space group Cmca (No. 64) and the lattice parameters a = 10.088(2), b = 8.051(5), c = 8.078(2) å, with 4 formular units per unit cell. The atomic arrangement of Ag2PdCl4 is explored by X-ray crystal structure analysis.Silver shows a distorted octahedral arrangement of chlorine atoms. Palladium forms typical, approximately square-planar PdCl4 groups. Ag2PdCl4 is a new variant of a partially occupied sodium chloride structure type.
    Notes: Die Kristallstruktur von Ag2PdCl4 wurde mit röntgenographischen Methoden an Einkristallen ermittelt. Ag2PdCl4 kristallisiert mit orthorhombischer Symmetrie: Cmca (No. 64), a = 10,088(2), b = 8,051(5), c = 8,078(2) å mit 4 Formeleinheiten pro Elementarzelle.Silber besitzt eine verzerrt oktaedrische Chlor-Nachbarschaft, während das Palladium annähernd quadratisch planare PdCl4-Gruppen bildet. Ag2PdCl4 stellt eine neue Variante einer teilbesetzten Natriumchloridstruktur dar.
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  • 72
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 562 (1988), S. 145-152 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Influence of Modification of γ-Alumina by Halides on the Acidic BehaviourThe influence of modification of γ-alumina by Cl and F on the acidic properties was studied by means of i.r. spectroscopic methods using ammonia as probe molecule. The measurements show a significant rise in Lewis acidity.
    Notes: Mittels IR-spektroskopischer Methoden wurde der Einfluß der Halogen-modifizierung auf das acide Verhalten von γ-Al2O3 im Hinblick auf dessen Verwendung als Träger in Reformingkatalysatoren untersucht. Als Sondenmolekül diente NH3. Die Messungen wiesen eine deutliche Verstärkung der Lewis-aciden Eigenschaften des modifizierten Al2O3 aus.
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  • 73
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 562 (1988), S. 141-144 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 27Al-NMR-Untersuchungen der flüssigen Phasen während der Zeolithsynthese27Al-NMR-Untersuchungen der während der Synthese der Zeolithe A, X und Y vorliegenden flüssigen Phasen zeigen, daß der molekulare Aufbau und die Menge der in den wäßrigen Lösungen vorliegenden Alumosilicationen für den entstehenden Zeolithtyp charakteristisch ist. Die Zahl der gebildeten Si—O—Al-Bindungen und ihre Mannigfaltigkeit steigt mit steigendem SiO2-Gehalt der Lösungen. Diese Ergebnisse stützen die Vorstellung, daß die Synthese von Zeolithen unter Ausbildung definierter Alumosilicate über die Lösungsphase abläuft.
    Notes: 27Al n.m.r. spectroscopy of liquid phases obtained during zeolite A, X, and Y synthesis reveals that the amount and the type of the present soluble aluminosilicate anions is characteristic for the different zeolite type; the number of the formed Si—O—Al bonds and their variety increases with increasing content of SiO2. The results support the suggestion about the formation mechanism of zeolites via distinct aluminosilicate “precursors” in solution.
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  • 74
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 562 (1988), S. 160-164 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Chalcogenolates. 186. Studies on Salts of Pyruvic Acid. 1. Synthesis and Characterization of PyruvatesThe title compounds M[O2C—CO—CH3], where M = Na, K, NH4, Li = H2, Have been synthesized by neutralisation of pyruvic acid under different conditions.The pyruvates were characterized by means of electron absorption, infrared, nuclear magnetic resonance, and mass spectra.
    Notes: Die Titelverbindungen M[O2C—CO—CH3] mit M = Na, K, NH4, Li · H2O wurden durch Neutralisation der Pyruvinsäure unter verschiedenen Bedingungen synthetisiert.Die Charakterisierung der Pyruvate erfolgte mit Hilfe von Elektronenabsorptions-, Infrarot-, Kernresonanz- und Massenspektren.
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  • 75
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 562 (1988), S. 153-159 
    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 Silicon-Sulphur Compounds. 52. Reaction of Trialkoxysilanethiols with Carboxylic Acids. Preparation and Hydrolysis of TrialkoxyacyloxysilanesThe series of trialkoxyacyloxysilanes have been prepared almost quantitatively from trialkoxysilanethiols (RO)3SiSH (R = i-Pr, s-Bu, s-n-Am, s-i-Am) by the reaction with carboxylic acids R′COOH (R′ = Alkyl or Ph). Kinetics of the acidolysis of (RO)3SiSH as well as hydrolysis of (RO)3SiOCOR′ were investigated and consequently the reaction mechanisms are proposed.
    Notes: Durch Umsetzung von Trialkoxysilanthiolen (RO)3SiSH (R = i-Pr, s-Bu, s-n-Am, s-i-Am) und Carbonsäuren R′COOH (R′ = Alkyl bzw. Ph) wurden fast quantitativ mehrere Trialkoxyacyloxysilane (RO)3SiOCOR′ erhalten. Die Kinetik dieser Acidolysereaktion von (RO)3SiSH wie auch der Hydrolysereaktion von (RO)3SiOCOR′ wurde untersucht und in der Folge die Reaktionsmechanismen formuliert.
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  • 76
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 563 (1988), S. 79-86 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Knowledge of Na6Cu2O6For the first time black single crystals of Na6Cu2O6 are obtained with a = 1094.8(1), b = 1203.6(1), c = 1638.1(2) pm, space group Cmca, Z = 12. Cu3+ is coordinated by four O2-. CuO4 groups are bound to planar, isolated Cu2O66- anions. Cu—O bond distances are between 181.6(3) and 186.4(4) pm and O—Cu—O bond angels in the range 84.0(1)° and 93.7(1)°. Effective Coordination Numbers, ECoN, Mean Fictive Ionic Radii, MEFIR, and the Madelung Part of Lattice Energy, MAPLE, are calculated.
    Notes: Erstmals wurden schwarze Einkristalle von Na6Cu2O6 mit a = 1094,8(1), b = 1203,6(1), c = 1638,1(2) pm, R. Gr. Cmca, Z = 12 dargestellt. Cu3+ ist planar von vier O2-umgeben. Je zwei CuO4-Gruppen sind zu planaren, isolierten Anionen Cu2O66- verknüpft. Die Abstände Cu—O liegen zwischen 181,6(3) und 186,4(4) pm, die Winkel O—Cu—O zwischen 84,0(1)° und 93,7(1)°. Die Effektiven Koordinationszahlen, ECoN, Mittleren Fiktiven Ionenradien, MEFIR, und der Madelunganteil der Gitterenergie, MAPLE, wurden berechnet.
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  • 77
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    Zeitschrift für anorganische Chemie 563 (1988), S. 70-78 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis, I.R. and E.P.R. Spectra, and Crystal Structure of HPPh3[WOCl4(OPPh3)]Partial hydrolysis of the alkyne complex [WCl4(PhC≡CPh)]2 in the presence of triphenylphosphine and dichloromethane as oxidizing agent and solvent yields dark green crystals of the complex HPPh3[WOCl4(OPPh3)]. Attempts to prepare the compound directly by the reaction of WOCl3 with PPh3, OPPh3 and HCl in dichloromethane were unsuccessful.HPPh3[WOCl4(OPPh3)] was characterized by its i.r. and e.p.r. spectrum. As shown by a crystals structure determination (1835 independent, observed reflections, R = 0.056) the complex crystallizes monoclinically in the space group P21/n with four formula units per unit cell. The complex consists of HPPh3+ and [WOCl4(OPPh3)]- ions, in which the tungsten atom is in a distorted octahedral environment, surrounded by four equatorial chlorine atoms, by one axial oxygen atom (bond length WO = 172 pm), and by the oxygen atom of the OPPh3 molecule (WO = 206 pm).
    Notes: HPPh3[WOCl4(OPPh3)] entsteht in Form dunkelgrüner Kristalle bei der partiellen Hydrolyse des Diphenylacetylenkomplexes [WCl4(PhC≡CPh)]2 bei Anwesenheit von Triphenylphosphan und Dichlormethan als Oxidations- und Lösungsmittel. Versuche, die Verbindung aus WOCl3, PPh3, OPPh3 und HCl in Dichlormethan direkt herzustellen, mißlangen.HPPh3[WOCl4(OPPh3)] haben wir durch das IR- und das EPR-Spektrum charakterisiert. Nach der röntgenographischen Strukturanalyse (1835 unabhängige, beobachtete, beobachtete Reflexe, R = 5,6%) kristallisiert die Verbindung monoklin in der Raumgruppe P21/n mit vier Formeleinheiten pro Elementarzelle. Sie ist aus HPPh3+-Ionen und Anionen [WOCl4(OPPh3)]- aufgebaut, in denen das Wolframatom verzerrt oktaedrisch von vier äquatorial angeordneten Chloratomen und axial von einem terminalen O-Atom (Bindungsabstand WO = 172 pm) und von dem O-Atom des OPPh3-Moleküls (WO = 206 pm) umgeben ist.
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  • 78
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 563 (1988), S. 105-115 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Complex Formation by Sulfonamide Substituted ThionoligandsThionoligands containing arenesulfonamido or arenesulfonylhydrazido functions as a second donor group (STAT-, PST-, BPTS- and TPTH-, meaning of the abbreviations see text) form 1,2 complexes with nickel(II), cobalt(II), and zinc(II). The six-membered chelates M(STAT)2 (M = Co, Ni) are high-spin (\documentclass{article}\pagestyle{empty}\begin{document}$ \rm{S} \mathop {\rm N}\limits^ \ominus $\end{document} coordination). On the other hand no coordination of the RSO2N group is observed in the complexes M(PST)2 (M = Co, Mn, Fe), but the formation of a four membered ring including one nitrogen atom of the heterocycle. This statement is primarily based on a comparison with complexes of teh structurally related ligands PPT- and CPT- containing no \documentclass{article}\pagestyle{empty}\begin{document}$ \rm{RSO}_2 \mathop {\rm N}\limits^ \ominus $\end{document} groups. Evidently in the chelat Co(BPTS)2 the anionic RSO2N group is a weak bidentate donor.
    Notes: Thionoliganden, die Arensulfonylamido- bzw. Arensulfonylhydrazidofunktionen als zweite Donatorgruppen enthalten (STAT-, PST-, BPTS- und TPTH-, zur Bedeutung der Abkürzungen vgl. Text), bilden mit Nickel(II), Cobalt(II) und Zink(II) 1,2-Komplexe. Die Sechsringchelate M(STAT)2 (M = Co, Ni) gehören zum High-spin-Typ (\documentclass{article}\pagestyle{empty}\begin{document}$ \rm{S} \mathop {\rm N}\limits^ \ominus $\end{document})-Koordination. Dagegen erfolgt in den Komplexen M(PST)2 (M = Co, Mn, Fe) keine Koordination über die \documentclass{article}\pagestyle{empty}\begin{document}$ \rm{RSO}_2 \mathop {\rm N}\limits^ \ominus $\end{document} Funktionen sondern über ein Stickstoffatom des Pyrimidinrings (Bildung eines Chelatvierringes). Diese Aussage wird durch einen Vergleich mit Komplexen der strukturell verwandten Liganden PPT- und CPT- gestützt, die keine RSO2N-Gruppen enthalten. In dem Chelat Co(BPTS)2 koordiniert RSO2N- offenbar als zweizähliger anionischer Ligand mit schwacher Donatorwirkung. Die Charakterisierung der neuen Chelate erfolgt anhand der magnetischen Momente, der UV/VIS- und der ESCA-Spektren. Die vorliegenden und früheren Ergebnisse ermöglichen Aussagen über die Variabilität des RSO2N-Liganden: Normalerweise erfolgt die Koordination über den N-Ligator. Es ist aber auch eine Bindung über ein Sauerstoffatom, wenn dadurch ein stabiler Chelatsechsring gebildet werden kann, oder als zweizähliger anionischer Ligand geringer Donatorstärke möglich. Die art der Koordination des RSO2N-Liganden hängt vom Zentralatom ab. Bisher konnten keine Komplexe mit einer direkten koordinativen Bindung von \documentclass{article}\pagestyle{empty}\begin{document}$ \rm{RSO}_2 \mathop {\rm N}\limits^ \ominus $\end{document} an Eisen(II) oder Mangan (II) nachgewiesen werden.
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  • 79
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    Zeitschrift für anorganische Chemie 563 (1988), S. 96-104 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses and Structure Analyses of Iodocuprates (I). IX. Syntheses and Crystal Structures of Cs3Cu2I5 and RbCu2I3Cs3Cu2I5 and Rb∞1[Cu2I3] were prepared by the reaction of CsI or RbI with CuI in solution (acetonitrile or acetone) or by solid state reaction. The crystal structure analysis of Cs3Cu2I5 (orthorhombic, Pbnm, a = 1438.6(6), b = 1014.7(5), c = 1167.5(5) pm, Z = 4) shows, that the compound contains dinuclear anions Cu2I53- in which the I atoms are arranged to trigonal bipyramids; one CuI occupies one of the two I tetrahedral holes, the other a trigonal site of the neighbouring tetrahedron. Rb∞1[Cu2I3] (orthorhombic, Cmcm, a = 1070.6(7), b = 1338.3(8), c = 572.8(3) pm, Z = 4) is built up by CuI4 double chains; the compound is isomorphic with Cs∞1[Cu2I3].
    Notes: Cs3Cu2I5 und Rb∞1[Cu2I3] werden durch Umsetzung von CsI bzw. RbI mit CuI in Lösung (Acetonitril bzw. Aceton) oder durch Festkörperreaktion hergestellt. Die Kristallstrukturanalyse von Cs3Cu2I5 (orthorhombisch, Pbnm, a = 1438,6(6), b = 1014,7(5), c = 1167,5(5) pm, Z = 4) ergab, daß diese Verbindung zweikernige Anionen Cu2I53- enthält. Die Iodatome bilden eine trigonale Bipyramide mit einem CuI in einer der beiden Tetraederlücken. Das zweite CuI besetzt eine Dreiecksfläche des anderen Tetraeders. Im Rb∞1[Cu2I3] (orthorhombisch, Cmcm, a = 1070,6(7), b = 1338,3(8), c = 572,8(3) pm, Z = 4) liegen CuI4-Tetraederdoppelketten vor; die Verbindung ist isomorph mit CsCu2I3.
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  • 80
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    Zeitschrift für anorganische Chemie 563 (1988), S. 87-95 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Chalcogenolates. 187. Studies on Salts of the Pyruvic Acid. 2. Crystal Structure of Potassium Pyruvate, Redetermination of the Structure of Sodium PyruvateThe title compounds M[O2C—CO—CH3], where M = Na and K, crystallize with Z = 4 in the monoclinic space group P21/n; cell dimensions see “Inhaltsübersicht”.The structure of the Na+ and K+ salt resp. has been determined from single crystal X-ray data measured at 20°C and refined to R's of 0.051 and 0.055 resp. (Rw = 0.055 and 0.057 resp.) for 1065 and 1308 resp. independent reflections.Both compounds are isostructural. The alkali metal ions are surrounded by seven oxygen atoms from five anions forming an irregular polyhedron.
    Notes: Die Titelverbindungen M[O2C—CO—;CH3] mit M = Na, K kristallisieren monoklin mit Z = 4 in der Raumgruppe P21/n; Na[O2C—CO—CH3] a = 21, 905(3) Å, K[O2C—CO—CH3] a = 22,027(2) Å, b = 5,269(1) Å, b = 5,835(2) Å, c = 3,671(1) Å, c = 4,004(4) Å, β = 91,34(2)°. β = 90,88(3)°. Für die Na+-bzw. K+-Verbindung wurde die Struktur aus bei 20°C vermessenen röntgenographischen Einkristalldaten unter Verwendung von 1065 bzw. 1308 symmetrieunabhängigen Reflexen bestimmt und bis auf Gütefaktoren von R = 0,051 bzw. 0,055 und Rw = 0,055 bzw. 0,057 verfeinert.Beide Verbindungen sind isostrukturell. Das jeweilige Alkalimetallion ist von sieben O-Atomen, die von fünf verschiedenen Anionen stammen, unregelmäßig koordiniert.
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  • 81
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    Zeitschrift für anorganische Chemie 563 (1988), S. 127-135 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on Oxide Catalysts. XLV. Conversion of Aromatics on Dealuminated Zeolites ZSM-5The catalytic properties of zeolites ZSM-5 dealuminated by hydrochloric acid are investigated in the isomerization of m-Xylene, the disproportionation of toluene and in the alkylation of toluene with methanol. Besides the increase of the Si/Al ratio, the dealumination leads to an inversion of the Si/Al concentration gradient in crystallites, to a shift of acidity spectrum and consequently to a change in catalytic activity and selectivity.
    Notes: An säuredealuminierten HZSM-5-Proben werden die m-Xylen-Isomerisierung, die Toluendisproportionierung und die Toluenalkylierung mit Methanol untersucht. Die Säuredealuminierung bewirkt neben der Moduländerung eine Umkehr des Si/Al-Konzentrationsgradienten in den Zeolithkristalliten, eine Verschiebung des Aciditätsspektrums und damit eine Veränderung von Aktivität und Selektivität in den katalytischen Reaktionen.
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  • 82
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    Zeitschrift für anorganische Chemie 563 (1988), S. 167-172 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tetraphenyl Imidodiphosphate as Ligand in Fluoro Complexes. 1. Fluoro Complexes of TitaniumIn acetonitrile TiF4 reacts with tetraphenyl imidodiphosphate forming two tetrafluoro (I, II) and three trifluoro complexes (III, IV, V) as well as one difluorotitanium complex (VI). The difluoro complex VI is exclusively formed by sing an excess of the ligand. VI was isolated and analytically characterized. The constitution and configuration of the complexes are concluded from 19F and 31P n.m.r. data. The tetraphenyl imidodiphosphate is only bidentately bonded, i.e. as chelate or bridging ligand; in the substitution complexes III-VI it is coordinated as anion.
    Notes: TiF4 bildet mit Imidodiphosphorsäuretetraphenylester in CH3CN zwei Tetrafluoro- (I, II) und drei Trifluorokomplexe (III, IV, V) sowie einen Difluorotitan-Komplex (VI). Mit Ligandenüberschuß entsteht ausschließlich der Difluorokomplex, der isoliert und elementar-analytisch charakterisiert wurde. Die Konstitutions- und Konfigurationsaussagen zu den übrigen Komplexen basieren auf 19F- und 31P-NMR-Untersuchungen. Der Imidodiphosphorsäureestr ist in den Komplexen stets zweizähnig als Chelat- oder Brückenligand gebunden; in den Substitutions-komplexen III-VI ist er in seiner anionischen Form enthalten.
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  • 83
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    Zeitschrift für anorganische Chemie 563 (1988), S. 116-126 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Methyl Metal Bis(trimethylsilyl)amido Derivatives of Aluminium, Gallium, and ArsenicMeAl[N(SiMe3)2]2 (Me = CH3) has been prepared by the reaction of AlMe3 with HN(SiMe3)2 in a 1:2 molar ratio. The homologue Gallium compound (as well as the Aluminium derivative) is formed in good yields by the interaction of MeMcl2 (M = Al, Ga) with Li- and Na[N(SiMe3)2], respectively. MeAs[N(SiMe3)2]2 is formed by the reaction of AsCl3 and Na[N(SiMe3)2] in a 1:3 molar ratio. These colourless amido derivatives are monomeric in solution, they have been characterized by analyses, mass, n.m.r. (1H and 13C), and especially by i.r. and Raman spectra.
    Notes: MeAl[N(SiMe3)2]2 (Me = CH3) wurde durch Umsetzung von AlMe3 mit HN(SiMe3)2 im Molverhältnis 1:2 dargestellt. Die homologe Galliumverbindung (wie auch das Aluminiumderivat) bildet sich in guten Ausbeuten aus MeMCl2 (M =; Al, Ga) und Li- bzw. Na[N(SiMe3)2]. Schließlich entsteht MeAs[N(SiMe3)2]2 bei der Reaktion von AsCl3 mit Na[N(SiMe3)2] im Verhältnis 1:3. Diese farblosen Amidoderivate sind in Lösung monomer; sie werden elementar-analytisch, mit Hilfe der Massen- und NMR-Spektren (1H und 13C) sowie vornehmlich schwingungs-spektroskopisch (IR und Raman) charakterisiert.
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  • 84
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: mehrkernige Technetium-Cluster. I. Synthese, Kristall- und Molekularstruktur der Bromide achtkerniger prismatischer und sechskerniger oktaedrischer Cluster des TechnetiumsE werden die Synthese, Kristall- und Molekularstruktur erster Vertreter mehrkerniger Technetium-Cluster er Zusammensetzung: [Tc8Br4μ—Br8]Br. 2 H2O; [H(H2O)2][Tc8Br4μ—Br8]Br; [H(H2O)2]2[Tc8Br4μ—Br8]Br2; [H3O(H2O)3]2[Tc6Br6μ3—Br5]; [(C4H9)4N]2[Tc6Br6μ3—Br5]; [H3O(H2O)3]2[Tc6Br6μ3—Br5]. 4 H2O beschrieben. Diese Verbindungen unterscheiden sich in ihrem Bau wesentlich von bekannten Clustern anderer d-Elemente. Die Kristall- und Molekularstruktur von Hexabromotechnetiumsäure, (H3O)2TcBr6, ist untersucht worden.
    Notes: The synthesis, crystal and molecular structure of the first representatives of polynuclear technetium clusters are described. The composition of these clusters is: [Tc8Br4μ—Br8]Br. 2H2O; [H(H2O)2][Tc8Br4μ—Br8]Br; [H(H2O)2]2[Tc8Br4μ—Br8]Br2; [H3O(H2O)3]2[Tc6Br6μ3—Br5]; [(C4H9)4N]2[Tc6Br6μ3—Br5]; [H3O3]2[Tc6Br6μ3—Br5]. 4 H2O. It is shown that these clusters strongly differ in their structure from the known clusters of other d-elements. The crystal and molecular structure of hexabromotechetium acid (H3O)2TcBr6 is studied too.
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  • 85
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 567 (1988), S. 48-59 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (Pentacarbonyl)tungsten Complexes of Diphosphanyl AcetylenesPreparation and properties of the following compounds are described: (Pentacarbonyl)tungsten complexes of diamidophosphoryl-diaminophosphanyl acetylenes (3, 4), of diamidothiophosphoryl-diaminophosphanyl acetylenes (5, 6) and of bis(diaminophosphanyl)-acetylenemethiodides (7, 8). Furthermore, the (pentacarbonyl)tungsten complexes of numerous halogenated diphosphanyl acetylenes have been prepared (15-21). All compounds are characterized by their n.m.r., i.r., and partly their mass spectra. Of (Pentacarbonyl)bis[bis(diethylamino)phosphanyl]acetylenemethiodide tungsten, 7, the molecular and crystal structures are reported.
    Notes: Darstellung und Eigenschaften der folgenden Verbindungen werden beschrieben: (Pentacarbonyl)wolfram-Komplexe von Diamidophosphoryl-diaminophosphanyl-acetylenen (3, 4), von Diamidothiophosphoryl-diaminophosphanyl-acetylenen (5, 6) und von Bis(diaminophosphanyl)-acetylenmethiodiden (7, 8). Weiter wurden die (Pentacarbonyl)wolfram-Komplexe zahlreicher halogenierter Diphosphanyl-acetylene (15-21) dargestellt. Alle Verbindungen sind durch ihre NMR-, IR- und teilweise ihre Massenspektren charakterisiert. Von (Pentacarbonyl){bis[bis(diethylamino)phosphanyl]acetylenmethiodid}wolfram, 7, werden die Molekül- und Kristallstruktur mitgeteilt.
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  • 86
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 567 (1988), S. 77-86 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of CsVHP3O10Hitherto unknown CsVHP3O10 crystallizes from melts prepared from Cs2CO3, V2O3 and H3PO4 (2 d at 350°C; cooling rate: 10°/h). Best yields were obtained at a molar ratio 1:1:3 of the components. According to an X-ray crystal structure determination (C2/c; a = 1208.7(5), b = 877.7(3), c = 894.4(3) pm, β = 110.76(3)°; Z = 4; R = 0.043) the title compound is a catena-triphosphate. Bond lengths and angles are compared to those of triphosphates investigated earlier.
    Notes: Vorher unbekanntes CsVHP3O10 kristallisiert aus Cs2CO3/V2O3/H3PO4-Schmelzen (2 d bei 350°C, Abkühlrate: 10°/h). Optimale Ausbeuten werden bei einem molaren Verhältnis der Komponenten von 1:1:3 erzielt. Nach der Kristallstrukturanalyse (C2/c; a = 1208,7(5), b = 877,7(3), c = 894,4(3) pm, β = 110,76(3)°; Z = 4; R = 0,043) liegt ein catena-Triphosphat vor. Die Bindungslängen und -winkel im Anion werden mit denjenigen früher untersuchter catena-Triphosphate verglichen.
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  • 87
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 567 (1988), S. 69-76 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Note on the Structure of A2[HgO2] (A = K, Rb), Rb2 [NiO2], and Rb1.4K0.6[NiO2]Single crystals of K2[HgO2] (I), Rb2[HgO2] (II), Rb2[NiO2] (III) and Rb1,4K0,6[NiO2] (IV) have been prepared [mercurates: colourless; niccolates: dichroitic ambercoloured/green (III) resp. yellow/green (IV)] mid characterized by X-riay single crystal methods. They crystallize tetragonally in the Na2[HgO2]-type of structure (space group I4/mmm, Z = 2) with I: a = 392.0(1), c = 1397.4(3) pm; II: a = 413.9(1), c = 1423.9(2) pm; III: a = 416.6(1), c = 1314.6(2) pm; IV: a = 409.2(2), c = 1304.4(6) pm. The crystal structures have been refined (four circle diffractometer). The Madelung parts of lattice energy, MAPLE, effective coordination numbers, ECoN, these via mean fictive ionic radii, MEFIR, are calculated and discussed.
    Notes: K2[HgO2] (I) wurde erneut, Rb2[HgO2] (II), Rb2[NiO2] (III) sowie Rb1,4K0,6[SiO2](IV) erstmals in einkristalliner Form dargestellt und röntgenographisch untersucht. Kristalle der Mercurate sind farblos, jene der Niccolate dichroitisch bernsteinfarben/grün (III) bzw. gelb/grün (IV). Die Oxide kristallisieren tetragonal im Na2[HgO2]-Typ (Raumgruppe I4/mmm, Z = 2) mit I: a = 392,0(1), c = 1397,4(3) pm; II: a = 413,9(1), c = 1423,9(2) pm; III: a = 416,6(1), c = 1314,6(2) pm; IV: a = 409,2(2), c = 1304,4(6) pm. Die Strukturparameter wurden verfeinert (Vierkreisdiffraktometerdaten). Der Madelunganteil der Gitterenergie, MAPLE, sowie Effektive Koordinationszahlen, ECoN, diese über Mittlere Fiktive Ionenradien, MEFIR, werden berechnet und diskutiert.
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  • 88
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Eigenschaften von Bariumchlorophosphat (Apatit)-Leuchtstoffen bei Aktivierung mit zweiwertigem EuropiumEine Reihe von europiumaktivierten Barium- bzw. Calciumchlorophosphaten wurde in Pulverform dargestellt. Diese Leuchtstoffe sind isomorphe Vertreter der hexagonalen Chlorapatite (Ba, Ca, Mg)10(PO4)6Cl2. Neben Röntgendiffraktogrammen wurden Anregungs- und Emissionsspektren der Lumineszenz bei Zimmertemperatur und bei tiefen Temperaturen (T ∽ 4 K) untersucht. Steigender Calciumanteil beeinflußt die Lumineszenzeigenschaften dieser festen Lösungen durch Veränderung des am Eu2+-Ion wirkenden Kristallfelds. Das Erscheinen einer neuen Emissionsbande mit höherem Ca2+-Gehalt bei tiefen Temperaturen deutet auf Einbau der Eu2+-Ionen auf zwei verschiedenen Ba-Plätzen, so daß zwei Arten von Lumineszenzzentren auftreten. Die Lumineszenz entsteht durch Übergänge von der 4f65d- zur 4f7-Konfiguration des Eu2+.
    Notes: A series of powder materials of barium and calcium chlorophosphate activated by divalent europium have been prepared. These luminophors are isomorphous representatives of the hexagonal chlorapatites (Ba, Ca, Mg)10(PO4)6Cl2. In addition to x-ray diffractograms, excitation and emission spectra of luminescence have been studied at room and low temperatures (T ∽ 4 K). An increasing calcium content affects the luminescence properties of the solid solutions by changing the crystal field acting upon the Eu2+ ion. The appearance of a new low-temperature emission band with higher Ca2+ content indicates that the Eu2+ ions substitute on two different barium sites thus forming two types of luminescent centres. The luminescence arises from transitions between 4f65d and 4f7 configurations of Eu2+.
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  • 89
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 567 (1988), S. 87-94 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses and Crystal Structures of CsM2P5O16 (M = V, Fe)Upon heating of mixtures composed of Cs2CO3, H3PO4 and V2O3(Fe2O3) to 〉600°C, melts were formed, from which the title compounds crystallized during slow cooling. They form as well from CsVHP3O10 (CsFeHP3O10) by condensation, besides (CsPO3)n. According to crystal structure determinations (Pn; for M = V: a = 753.79(7), b = 941.05(12), c = 1 017.29(12) pm, β = 111.16(9)°; for M = Fe: a = 752.99(17), b = 937.77(44), c = 1 020.90(18) pm, β = 111.02(1)°; Z = 2) the anionic part of both compounds consists of catena-pentaphosphate groups. Systematic variations in the P—O bond lengths are discussed.
    Notes: Durch Erhitzen von Gemengen aus Cs2CO3, H3PO4 und V2O3(Fe2O3) auf 〉600°C entstehen Schmelzen, aus denen bei langsamem Abkühlen die vorher unbekannten Titelverbindungen kristallisieren. Sie bilden sich auch bei der thermischen Kondensation von CsVHP3O10 (CsFeHP3O10), wobei als Nebenprodukt (CsPO3)n anfällt. Nach der Röntgenstrukturanalyse (Pn; für M = V: a = 753,79(7), b = 941,05(12), c = 1 017,29(12) pm, β = 111,16(;9)° für M = Fe: a = 752,99(17), b = 937,77(44), c = 1 020,90(18) pm, β = 111,02(1)°; Z = 2) handelt es sich um catena-Pentaphosphate. Die systematische Variation der P—O-Bindungslängen im Anion wird diskutiert.
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  • 90
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 567 (1988), S. 95-100 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Na2H3IO6, a Variant of the Marcasite StructureSingle crystals of Na2H3IO6 were grown for the first time. According to the results of an X-ray crystal structure determination(Pnnm; a = 469.7(3), b = 529.9(2), c = 1005.2(6) pm; Z = 2; 296 diffractometer data; RW = 0.051) iodine is in an octahedral coordination. Sodium is surrounded by six oxygen in a strongly distorted octahedral arrangement. IO6 and NaO6 groups are linked via common vertices and edges in the sense of the rutile or marcasite type of structure. The corresponding structural relationship is discussed.
    Notes: Erstmals wurden Einkristalle von Na2H3IO6 erhalten. Nach der Röntgen-strukturanalyse (Pnnm; a = 469,7(3), b = 529,9(2), c = 1005,2(6) pm; Z = 2; 296 Diffraktometerdaten, RW = 0,051) ist Iod oktaedrisch und Natrium stark verzerrt oktaedrisch von Sauerstoff koordiniert. Die Verknüpfung der Oktaeder erfolgt im Sinne der Rutil- bzw. Markasitstruktur; die entsprechende Strukturverwandtschaft wird diskutiert.
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  • 91
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 567 (1988), S. 122-130 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: NMR-Untersuchungen an Stannabicycloundecanen des Typs RSn(CH2CH2CH2)3NEs werden 1H-, 13C- und 119Sn-NMR-Daten von sieben Stannabicycloundecanen des Typs RSn(CH2CH2CH2)3N (1, R = Cl; 2, R = Br; 3, R = I; 4, R = OH; 5, R = SPh; 6, R = Me; 7, R = Sn(CH2CH2CH2)3N) mitgeteilt. Aus den Protonen-NMR-Koaleszenzdaten bei tiefer Temperatur wird ΔGTc* für die Racemisierung des Bicyclo[3.3.3]-Gerüstes zu 37 ± 1 kJ/mol bestimmt. Die Werte sind unabhängig vom Substituenten R. In den entsprechenden Siliciumderivaten (R = Me) werden geringere Aktivierungsparameter gefunden.
    Notes: The 1H, 13C, and 119Sn NMR data of seven stannabicycloundecanes of the type RSn(CH2CH2CH2)3N (1, R = Cl; 2, R = Br; 3, R = I; 4, R = OH; 5, R = SPh; 6, R = Me; 7, R = Sn(CH2CH2CH2)3N) are reported. From 1H NMR coalescence data at low temperature the free activation enthalpies for the racemisation of the bicyclo[3.3.3]skeleton were estimated to be 37 ± 1 kJ/mol. They are independent of the substituent R. However, it decreases when the tin atom is replaced by silicon for R = Me.
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  • 92
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Monohalogenobenzoylhydrazone. V. Spektroskopische Untersuchungen und Bindungs-verhältnisse einiger neuer Antimon(III)-Komplexe von p-Chlorobenzoyl-di-(2-pyridyl)-ketohydrazon mittels experimenteller und quantenchemischer MethodenBei der Reaktion von Antimon(III)-chlorid, -bromid und -iodid mit dem p-Chlorobenzoylhydrazon des Di-(2-pyridyl)keton (DpClBHH) in methanolischer Lösung werden Komplexe des Typs SbX2(DpClBH) erhalten. Die Struktur dieser Verbindungen wird an Hand der spektroskopischen Daten diskutiert. Der Ligand koordiniert dreizähnig über die Carbonyl- und Azomethin-Gruppe sowie über den Stickstoff der Pyridyl-Gruppe. Eine verzerrt oktaedrische Koordination des Metalls wird vorgeschlagen. EH-MO-Rechnungen wurden zur Analyse der Elektronen-spektren und der Bindungsverhältnisse herangezogen. Weiterhin dienen Grenzorbital-Betrachtungen aus CNDO/2-Rechnungen zur Klärung der Metall-Liganden-Bindung.
    Notes: Reactions of antimony(III) chloride, bromide, and iodide with p-chlorobenzoylhydrazone of di-(2-pyridyl)ketone (DpClBHH) in methanolic solutions afford the complexes SbX2(DpClBH). The structures of the new compounds are discussed in relation to their spectroscopic properties. In these complexes the ligand behaved as terdentate, coordination occuring through the carbonyl and azomethine groups, as well as the nitrogen atom of the pyridyl group. Consequently, a distorted octahedral environment around the metal is proposed. Moreover, EHMO calculations have been used in the analysis of the bonding in the SbCl2(DpClBH) complex, as well as to interpret the electronic spectral data. In addition, CNDO/2 calculations performed on the aforesaid ligand have been used to throw light on the mode of attachment of the ligand to the metal ion by means of some quantum-chemical indices related to the frontier MO's.
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  • 93
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 567 (1988), S. 173-178 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mössbauer Studies of Thiospinels. VII. The System Cd0.9Fe0.1Cr2(SxSe1-x)4In order to investigate the influence of mixed anions on 57Fe-Mössbauer spectra of thiospinels with tetrahedral FeII polycrystalline samples of the spinel system Cd0.9Fe0.1Cr2(SxSe1-x)4 have been prepared in the range 0.22 ≤ x ≤ 1. Room temperature Mössbauer spectra consist of several overlapping doublets of almost identical isomer shifts but different quadrupole splittings. The FeII-doublets are attributed to the five different coordination polyhedras S4, S3Se, S2Se2, SSe3, and Se4.
    Notes: Um den Einfluß eines gemischten Anionengitters auf die 57Fe-Mößbauer-Spektren von Thiospinellen mit tetraedrischem FeII zu untersuchen, wurden von dem spinell-system Cd0,9Fe0,1Cr2(SxSe1-x)4 im Bereich 0,22 ≤ x ≤ 1 polykristalline Proben hergestellt. Die Raumtemperatur-Mößbauer-Spektren der Spinellmischkristalle bestehen aus mehreren überlappenden Dubletts nahezu gleicher Isomerieverschiebung aber verschiedener Quadrupolaufspaltung. Die FeII-Dubletts können den Koordinationspolyedern S4, S3Se, S2Se2, SSe3 und Se4 zugeordnet werden.
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  • 94
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    Zeitschrift für anorganische Chemie 567 (1988), S. 145-152 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Characterization of Non-Framework Aluminium in Zeolites Y by the Ferron MethodBy using the ferron method it is shown that the non-framework aluminium occuring in dealuminated zeolites Y exists in form of different kinds of Al-oxo-hydroxo-species. At the beginning of dealumination (673 K) besides polymeric species with relatively low degree of polymerization monomeric and a special kind of oligomeric cations occur. These special cations alter into a mixture of oligomeric species with increasing temperature of dealumination (813 K). Simultaneously the degree of polymerization of the polymeric species increases.
    Notes: Mit der Ferronmethode wird gezeigt, daß das in thermisch behandelten Y-Zeolithen auftretende Extragitter-Aluminium aus unterschiedlichen Arten von Al-oxo-hydroxo-Spezies besteht. Am Anfang der Dealuminierung (673 K) liegen neben monomeren spezielle oligomere Kationen vor; gleichzeitig werden aber auch polymere Spezies mit relativ niedrigem Polymerisationsgrad gebildet. Mit steigender Temperatur der thermischen Behandlung (813 K) entsteht aus den oligomeren Teilchen ein Gemisch niedermolekularer Kationen. Die polymeren Spezies unterliegen dabei einer Veränderung im Sinne einer zunehmenden Kondensation bzw. Polymerisation.
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  • 95
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 565 (1988), S. 47-53 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Chalcogenolates. 188. Preparation and Properties of Esters of Dithiopropionic AcidThe orange colored title compounds C2H5—CS—SR with R = CH3, C2H5, C(CH3)3, and CH2—C6H5 have been prepared in one-pot synthesis by reaction of ethyl bromide with magnesium followed by CS2 insertion and alkylation with the corresponding alkyl halide. Their electron absorption, infrared, nuclear magnetic resonance, and mass spectra are communicated.
    Notes: Die orangefarbene Titelverbindungen C2H5—CS—SR mit R = CH3, C2H5, C(CH3)3 und CH2—C6H5 wurden im Eintopfverfahren durch Umsetzung von Ethylbromid mit Magnesium, anschließender CS2-Insertion und Alkylierung mit dem entsprechenden Alkylhalogenid hergestellt. Ihre Elektronenabsorptions-, Infrarot-, Kernresonanz- und Massenspektren werden mitgeteilt.
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  • 96
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 565 (1988), S. 34-40 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: An Unusual System of Hydrogen Bonds in Rubidium Hydroxide Dihydrate, RbOH · 2 H2ORbOH · 2H2O was obtained by the reaction of Rb with H2O and dehydration of the resulting solution by concentrated sulfuric acid. The compound melts at 310 K. The structure was determined by X-ray single crystal methods: The H positions of H2O were found. The structure consists of a threedimensional H-bonded network of H2O molecules and OH-ions. Hydroxide ions are acceptors for four protons of four adjacent water molecules with d(O—O) = 2×2.59 Å and 2×2.82 Å. Oxygen of OH-ions is disordered over a distance of 1.27 Å. Rb has 8 H2O molecules as nearest neighbours, d(Rb—O) = 3.03 Å to 3.07 Å, OH-ions are further removed with d(Rb—O) ≥ 3.45 Å.
    Notes: RbOH · 2H2O wird durch Umsetzung von Rb mit H2O und Entwässern der entstehenden Lösung über konzentrierter H2SO4 erhalten. Die Verbindung schmilzt bei 310 K. An Einkristallen wurde ihre Struktur röntgenographisch bestimmt: Die H-Lagen an den H2O-Molekülen konnten ermittelt werden. Die Struktur zeigt ein brückengebundenes Gerüst von H2O-Molekülen und OH--Ionen. Die Hydroxidionen dienen als Akzeptoren für je ein Proton von vier benachbarten H2O-Molekülen mit d(O—O) = 2×2,59 Å und 2×2,82 Å. Der Sauerstoff des OH--Ions ist fehlgeordnet mit einem Abstand von 1,27 Å. Rb hat 8 H2O-Moleküle als nächste Nachbarn, d(Rb—O) = 3,03 bis 3,07 Å, OH--Ionen sind weiter entfernt mit d(Rb—O) ≥ 3,45 Å.
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  • 97
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    Zeitschrift für anorganische Chemie 565 (1988), S. 54-66 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Structure of M1—LnTa3O9 (Ln = Pr, Nd), X-Ray and Electronmicroscopical InvestigationsNew ternary compounds M1—LnTa3O9 (Ln = Pr, Nd) could be prepared by chemical transport reaction in a temperature gradient T2 → T1 (T2 = 1100°C; T1 = 1000°C; CI2 as transport agent). M1 NdTa3O9 crystallizes in the monoclinic space group P 21/m with a = 5.3840(9) Å, b = 7.550(1) Å, c = 8.1911(9) Å and β = 92.46(1)°. The structure was refined to give R = 6.29% and Rw = 6.20%. It is built of double and single chains of corner-sharing TaO6 octahedra extended along the b-axis. Tunnels running along [010] are created by the framework of TaO6 octahedra. Ln (Ln = Pr, Nd) is located in these tunnels to levels of y = 1/4 and 3/4. A structure refinement for isostructural M1—PrTa3O9 led to a = 5.4051(7) Å, b = 7.5680(2) Å, c = 8.1964(9) Å, β = 92.38(2)° and R = 7.72%, Rw = 7.57%. By grinding in an agate mortar M1—LnTa3O9 transforms into M2—LnTa3O9, a new modification with a higher density.High resolution transmission electron microscopy images of the M1—PrTa3O9 structure were made along the [010] direction. They could be interpreted by comparing them with images calculated on the basis of the multi-slice method.
    Notes: Durch chemischen Transport im Temperaturgefälle T2 → T1 (T2 = 1100°C; T1 = 1000°C) mit dem Transportmittel Chlor (p(Cl2; 20°C) = 1 atm) wurden die neuen Verbindungen M1—LnTa3O9 (Ln = Pr, Nd) erhalten. Die Strukturbestimmung über Einkristalldaten ergab für M1—NdTa3O9: RG P21/m;a = 5,3840(9) Å, b = 7,550(1) Å, c = 8,1911(9) Å, β = 92,46(1)°; Z = 2; R = 6,29%, Rw = 6,20%. Es liegen TaO6-Oktaeder vor, die allseitig über Ecken miteinander verknüpft und zum Teil auch über Kanten zu Oktaederpaaren verbunden sind. In Richtung [010] wechseln sich Oktaeder und Oktaederpaare ab. In den längs b verlaufenden Kanälen zwischen den Oktaederpaaren befinden sich die Nd-Teilchen. Die Strukturverfeinerung am isotypen M1—PrTa3O9 führte zu den Gitterkonstanten a = 5,4051(7) Å, b = 7,5680(2) Å, c = 8,1964(9) Å, β = 92,38(2)° und R = 7,72%, Rw = 7,57%.Beim Zerreiben der Kristalle von M1—LnTa3O9 (Ln = Pr, Nd) erfolgt eine tribochemische Umwandlung in eine weitere neue Modifikation M2—LnTa3O9 mit signifikant höherer Dichte.Von M1—PrTa3O9 konnten hochaufgelöste elektronenmikroskopische Durchstrahlungsaufnahmen längs [010] erhalten werden. In Übereinstimmung mit der rechnerischen Kontrastsimulation sind die unbesetzten Kanäle bei einem Defokus von -1150 Å deutlich als heller Kontrast erkennbar.
    Additional Material: 5 Ill.
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  • 98
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 565 (1988), S. 67-80 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Structure of New CeTa3O9 ModificationsThe modifications M—, O— and P—CeTa3O9 could be prepared by chemical transport reactions (T2 → T1; T2 = 1100°C; T1 = 1000°C) with chlorine as transport agent.M—CeTa3O9 crystallizes in the monoclinic space group C 2/m with a = 12.415(1) Å, b = 7.6317(8) Å, c = 6.5976(8) Å, β = 93.31(1)°; Z = 4; R = 4.88%, Rw = 3.67%. The structure consists of two types of Ta—O-polyhedra. Especially remarkable are chains of edge sharing pentagonal TaO7-bipyramids which are connected by TaO6-octahedra at opposite sides. Tunnels running along [010] are created by the framework of Ta—O-polyhedra and are filled with Ce in levels of y = 1/2 and y = 0.O—CeTa3O9 crystallizes orthorhombically with a = 6.5429(7) Å, b = 7.6491(7) Å, c = 12.583(1) Å and is isostructural to O—LaTa3O9 (space group: Pnma). O—CeTa3O9 contains the same characteristic structural units namely pentagonal TaO7-bipyramides and TaO6-octahedra. The difference between O— and M—CeTa3O9 is based on the orientation of the tunnels: in the orthorhombic modification they are arranged zigzag-like, in the latter parallel.Both modifications of CeTa3O9 can be irreversibly converted into the well-known perovskite-related P—CeTa3O9 structure with a lower density by heating in air to 1200°C.
    Notes: Durch chemischen Transport (T2 → T1; T2 = 1100°C; T1 = 1000°C) mit dem Transportmittel Chlor (p(Cl2; 298 K) = 1 atm) wurden Kristalle der neuen Modifikationen M— und O—CeTa3O9 sowie von der Perowskitvariante P—CeTa3O9 erhalten. Nach der Strukturbestimmung über Einkristalldaten ist M—CeTa3O9 monoklin (C 2/m) mit a = 12,415(1) Å, b = 7,6317(8) Å, c = 6,5976(8) Å, β = 93,31(1)°; Z = 4; R = 4,88%, Rw = 3,67%. Man erkennt aus kantenverknüpften pentagonalen TaO7-Bipyramiden bestehende Bänder längs c, die miteinander durch TaO6-Oktaeder verbunden sind. In den so gebildeten Kanälen sind die Cer-Teilchen lokalisiert.O—CeTa3O9 kristallisiert orthorhombisch mit a = 6,5429(7) Å, b = 7,6491(7) Å, c = 12,583(1) Å und ist nach Pulveraufnahmen isotyp mit der bereits näher untersuchten Verbindung O—LaTa3O9. Beide orthorhombischen Oxide sind wie M—CeTa3O9 durch ein Netzwerk kantenverknüpfter TaO7- und TaO6-Polyedern gekennzeichnet; in [010]-Richtung liegen nur Eckenverknüpfungen vor. Die TaO6-Oktaeder sind in der a—c-Ebene jeweils so angeordnet, daß die mit Ce (La) besetzten Kanäle bei O—CeTa3O9 zick-zack-förmig, bei M—CeTa3O9 parallel zueinander orientiert erscheinen.O— und M—CeTa3O9 zeigen beim Erhitzen (1200°C; an Luft) eine nicht reversible Umwandlung in die bekannte Perowskitmodifikation P—CeTa3O9 (Ce1/3TaO3) mit deutlich geringerer röntgenographischer Dichte.
    Additional Material: 4 Ill.
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  • 99
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 565 (1988), S. 106-110 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Structure of NaRhO2For the first time black single crystals of NaRhO2 (from Li2O, NAO0,50 α-Rh2O3, Li: Na: Rh = 1,15:2.18:1, Pd-cylinder, 950°C, 18 d, in 18 d cooled down) have been prepared and investigated by X-ray. NaRhO2 crystallizes in the α-NaFeO2-type: a = 309.71(4), c = 1552,75(34) pm, c/a = 5.01, space group R3m, Z = 3; fourcircle diffractometer data (Philips PW 1100): 124 of 126 I0(hkl): AgKα; R = Rw = 3.44%). The Madelung Part of Lattice Energy, MAPLE, and peculiarities of this type of structure are discussed.
    Notes: Erstmals wurden schwarze Einkristalle von NaRhO2 (aus Li2O, NaO0,50 und α-Rh2O3, Li: Na: Rh = 1,15:2,18:1, Pd-Bömbchen, 950°C, 18 d, 18 d abgekühlt) dargestellt und röntgenographisch untersucht. NaRhO2 kristallisiert im rhomboedrischen α-NaFeO2-Typ: a = 309,71(4), c = 1552,75(34) pm, c/a = 5,01, Raumgruppe R3m, Z = 3; Vierkreisdiffraktometerdaten (Philips PW 1100): 124 von 126 I0(hkl); AgKα; R = Rw = 3,44%). Der Madelunganteil der Gitterenergie, MAPLE, und Charakteristika des Strukturtyps werden diskutiert.
    Additional Material: 6 Tab.
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  • 100
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 565 (1988), S. 81-90 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chloro-Fluro-Exchange by Halogenated 1.3-DisilazanesAminofluorosilance (1-4) are obtained in the reaction of difluorosilanes with lithiated amines. Disilazanes (5,6) are formed in the reaction of LiNH(C6H3-iPr2) with CMe3SiF3 and C6H5SiF3. Lithium salts of 1-4 are dimers in n-hexane (7-10) and LiF adducts of iminosilanes in THF (11-14). The latter react with chlorsilanes (RSiCl3, R = Cl, H, Me) to give the substituted compounds 15-21 and LiCl. An intermolecular F/Cl exchange occurs with 15-20 which depends on the temperature, the solvents and ligands. 22-27 are formed.
    Notes: Aminofluorsilance (1-4) werden durch die Reaktion der Difluorsilane mit lithiierten Aminen erhalten. CMe3SiF3 und C6H5SiF3 reagieren zu Disilazanen (5,6). Die Lithiumsalze von 1-4 bilden in n-Hexan Dimere (7-10) und in THF LiF-Addukte von Iminosilanen (11-14). Letztere reagieren mit Chlorsilanen (RSiCl3, R = Cl, H, Me) unter LiCl-Abspaltung und Substitution zu 15-21 . 15-20 unterliegen einem intermolekularen F/Cl-Austausch, der temperatur-, lösungsmittel- und substituentenabhängig ist. Es entstehen 22-27 .
    Additional Material: 1 Ill.
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