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  • 1995-1999  (7,562)
  • 1985-1989  (3,944)
  • 1980-1984  (2,663)
  • Biochemistry and Biotechnology  (10,099)
  • Industrial Chemistry  (1,973)
  • Gas chromatography
  • Nuclear reactions
  • Ultrastructure
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Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Detection of adulteration of pumpkin seed oil by analysis of content and composition of specific Δ7-phytosterols (1999)
    Springer
    European food research and technology 209 (1999), S. 400-406 
    Details
    ISSN: 1438-2385
    Keywords: Key words Pumpkin seed oil ; Oil adulteration ; Δ7-Phytosterols ; Sample clean-up procedure ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  A simple and accurate method for the determination of phytosterols by capillary gas chromatography was developed for the analysis of the seeds and oil of the pumpkin Cucurbita pepo L., the naked seed variety growing in the southern Styrian parts of Austria. After extraction of the oil and saponification, the remaining unsaponifiable material was isolated and purified using silica gel columns. For greater volatility, the sterols were derivatised to trimethylsilylethers, and gas chromatography was performed on a column of high polarity, allowing separation of the Δ5-sterols from the Δ7-sterols and thus yielding a typical chromatographical pattern. Quantification of the phytosterols using 5α-cholestan or cholesterol as internal standards led to a method of high accuracy. Comparison of the chromatographic pattern of the phytosterol fraction of pumpkin seed oil with those of other vegetable oil samples permitted the use of this method to detect adulteration of pumpkin seed oil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002170050516
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  • 2
    Electronic Resource
    Electronic Resource
    Hydroxyproline interference during the gas chromatographic analysis of D/L aspartic acid in human dentine (1999)
    Springer
    International journal of legal medicine 112 (1999), S. 124-131 
    Details
    ISSN: 1437-1596
    Keywords: Key words Hydroxyproline ; D/L Aspartic acid ; N-TFA isopropyl ester derivatives ; Gas chromatography ; Collagen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Notes: Abstract The proportion of D- to L-enantiomers of aspartic acid in metabolically isolated proteins has been used by forensic scientists to estimate age at death. We have demonstrated the interference of a derivative of hydroxyproline (N-TFA isopropyl Hyp ester) with the N-TFA isopropyl L-Aspartic (Asp) acid ester during gas chromatography of amino acids. This has serious implications for the accurate quantification of the D- to L-Asp ratio extracted from collagenous proteins. Having demonstrated the potential for this co-elution in amino acid standards, acid-soluble dentine proteins and non-mineralised collagen, we argue that this problem can be overcome either by high resolution separation or by analysis of the (Hyp-poor) non-collagenous protein fraction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004140050214
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  • 3
    Electronic Resource
    Electronic Resource
    Electron microscopic stereology of capillary endothelial cells and cardiomyocytes in artificially arrested canine hearts (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 151-160 
    Details
    ISSN: 1437-773X
    Keywords: Key words Heart ; Ultrastructure ; Capillaries ; Endothelium ; Stereology ; Cardioplegic solutions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In open heart surgery and transplantation, sufficient structural preservation of the myocardium immediately following cardioplegic arrest is a precondition for overcoming ischemia and for resumption of postischemic function. Therefore, we compared the protective effect of three clinically applied cardioplegic solutions with fibrillating and beating hearts using structural criteria. Left ventricular samples were taken from (1) beating, or (2) fibrillating or arrested hearts following coronary perfu-sion with (3) St. Thomas' Hospital solution, (4) histidine tryptophane ketoglutalate (HTK) (Custodiol), or (5) University of Wisconsin (UW) solution and fixed by immersion. Ultrastructural differences in the swelling of capillary endothelial cells and myocytes were quantitatively evaluated using stereological methods. Endothelial cells were somewhat more swollen after St. Thomas perfusion than those in beating and fibrillating hearts. HTK-arrested hearts showed significantly lower values for cellular edema than beating hearts. UW perfusion resulted in the (significantly) lowest degree of endothelial cell edema. Edematous changes in myocytes were significantly greater in St. Thomas-arrested hearts than in UW- or HTK-arrested hearts. Cardiomyocyte edema in beating and fibrillating hearts was comparable to that in St. Thomas-perfused hearts. Thus, the stereol-ogical analysis revealed significant differences between cardioplegic solutions in structural preservation of myocardial ultrastructure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007950050022
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  • 4
    Electronic Resource
    Electronic Resource
    Secretory carcinoma of the breast: an immunohistochemical and ultrastructural study (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 50-56 
    Details
    ISSN: 1437-773X
    Keywords: Key words: Secretory carcinoma ; Breast ; Intracytoplasmic lumina ; Immnohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report a rare case of secretory carcinoma of the breast in a 50-year-old Japanese woman. The patient had been aware of a right breast tumor for 8 years, but had left it untreated. The tumor enlarged in size and became painful, and she visited our hospital. Breast carcinoma was diagnosed, and mastectomy was performed. Histopathological examination revealed features of a secretory carcinoma characterized by prominent secretory activity in the glandular and microcystic spaces, with some areas showing a follicular pattern resembling the thyroid gland. The secretory material was PAS-positive and immunohistochemically α-lactalbumin-positive. Ultrastructurally, the tumor cell contained many secretory vacuoles in the cytoplasm. In addition, extracellular and intracytoplasmic lumina were conspicuous; these were lined by microvilli projection and contained secretory material. By flow cytometric analysis, the DNA index was 1.14, which was diploid, showing relatively low proliferative activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007950050008
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  • 5
    Electronic Resource
    Electronic Resource
    Ultrastructure of Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus-8 (HHV-8) in a primary effusion lymphoma cell line treated with tetradecanoyl phorbol acetate (TPA) (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 94-99 
    Details
    ISSN: 1437-773X
    Keywords: Key words KSHV ; HHV-8 ; TPA ; Ultrastructure ; Primary effusion lymphoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The ultrastructure of Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus-8 (HHV-8) has not yet been fully elucidated, although some findings have been reported using primary effusion lymphoma (PEL) cell lines, KS-1, harboring no Epstein–Barr virus (EBV) coinfection. In the present study, detailed fine structural examination of KSHV/HHV-8 was performed after stimulation of the PEL-derived cell line KS-1 with 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in vitro. While unstimulated KS-1 cells contained a small number of intranuclear virus particles associated with no extracellular mature particles, KS-1 cells stimulated with TPA produced many extracellular mature particles as well as intranuclear particles, in addition to interesting tubulo-reticular structures and aggregated tubular structures in vesicles. The induced intranuclear particles were empty, doughnut shaped, and dense cored, with outer and inner diameters of 100–110 nm and 60–70 nm, respectively. Dense-cored extracellular mature particles were 150–160 nm in diameter, and some contained doughnut-shaped cores, together with a few megaloviruses, 260 nm in outer diameter. These findings indicate that KS-1 cells treated with TPA can produce extracellular mature particles as well as intranuclear particles, which were proven to be KSHV/HHV-8.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007950050014
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  • 6
    Electronic Resource
    Electronic Resource
    The protective effect of hepatocyte growth-promoting factor (pHGF) against carbon tetrachloride-induced acute liver injury in rats: an ultrastructural study (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 184-192 
    Details
    ISSN: 1437-773X
    Keywords: Key words pHGF ; HGF ; Acute liver injury ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The protective effect of hepatocyte growth-promoting factor (pHGF) against CCl4-induced acute hepatitis in rats was examined by light and electron microscopy. Hepatocyte growth-promoting factor, purified from infant pig liver in an active form, has been used clinically in patients with hepatitis in China. Four hours after administration of CCl4, a single dose of pHGF was administered intraperitoneally. Six hours after administration of CCl4, inhibition of CCl4-induced hepatic necrosis and hepatocytes with severely dilated endoplasmic reticula were evident in rats treated with pHGF. At 48 h post administration, most hepatocytes had recovered, and not only mitotic hepatocytes (10–13 mitotic cells/100) but also mitotic Kupffer cells were observed. At 72 h, it was evident that the differentiation of hepatic stellate cells (Ito cell) into myofibroblast-like cells and the development of fibrosis around the central veins was prevented by pHGF. These results suggested that (1) pHGF may stabilize cell membranes, (2) pHGF acts as a mitogen not only for hepatocytes but also for Kupffer cells, and (3) pHGF prevents fibrogenesis in the case of CCl4-induced liver injury by preventing the differentiation of hepatic stellate cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007950050026
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  • 7
    Electronic Resource
    Electronic Resource
    Changes in cerebral blood flow and blood brain barrier in the gerbil hippocampal CA1 region following repeated brief cerebral ischemia (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 175-183 
    Details
    ISSN: 1437-773X
    Keywords: Key words Cerebral blood flow ; Blood–brain barrier ; Repeated brief cerebral ischemia ; Hippocampal CA1 ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Neuronal damage and changes in cerebral blood flow (CBF) and the permeability of the blood–brain barrier (BBB) following repeated brief periods of ischemia were studied in Mongolian gerbils. The cerebral ischemia was produced by three repeated occlusions of bilateral common carotid arteries for 3 min at 1-h intervals. CBF and permeability of the BBB were examined with tracers (China ink and silver nitrate) at 1, 3, and 7 days post ischemia using light and electron microscopy. Three days after the reperfusion, significant extravasation of tracers, consequential reduction of CBF, extensive neuronal destruction, and intravascular platelet aggregation were observed. Such vascular changes in the CA1 region were more severe than those in the frontal cortex. These findings strongly support the view that microcirculatory disturbance may be a mechanism responsible for delayed neuronal death in the CA1 region of the hippocampus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007950050025
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  • 8
    Electronic Resource
    Electronic Resource
    Ultrastructural study of the destructive and repair processes in pulmonary inflammation and following endobronchial laser therapy (1999)
    Springer
    Virchows Archiv 435 (1999), S. 13-19 
    Details
    ISSN: 1432-2307
    Keywords: Key words Inflammation of the lung ; Biopsy ; Ultrastructure ; Laser therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Examination of 127 biopsy specimens from 45 patients with inflammatory lung diseases showed changes consistent with increased permeability of the capillary endothelial cells as an initial stage in the development of the inflammatory reaction. Associated interstitial oedema, deformation of the interalveolar septa, and structural disorganization of alveolar epithelium cells occur, and local microcirculatory problems result in tissue hypoxia and fibrosis. The ultimate morphological picture is determined largely by the intensity of repair. Laser biostimulation minimizes the inflammation and stabilizes fibroplastic process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280050389
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  • 9
    Electronic Resource
    Electronic Resource
    Evaluation of muscle capillary basement membrane in inflammatory myopathy (1999)
    Springer
    Virchows Archiv 435 (1999), S. 58-61 
    Details
    ISSN: 1432-2307
    Keywords: Key words Capillary basement membrane ; Inflammatory myopathy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The capillary basement membranes from 16 skeletal muscle biopsies from patients with a clinical and histological diagnosis of inflammatory myopathy and from six controls were analysed ultrastructurally and morphometrically. Resin sections from 244 endomysial capillaries were examined by light microscope, and the results were correlated with findings seen in electron micrographs of these capillaries. The ultrastructural morphometric measurements and the statistical analysis showed that the capillary basement membrane was thick and multilaminated in 87% specimens affected by inflammatory myopathy. No thick or multilaminated basement membrane was observed in controls. In inflammatory myopathy the endomysial space next to the capillaries contained an increased amount of collagen fibrils and showed signs of a chronic reparative process. It is suggested that the thick multilaminated basement membrane in inflammatory myopathy represents an advanced stage of vascular regeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280050395
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  • 10
    Electronic Resource
    Electronic Resource
    The effects of cold-restraint stress on urinary bladder wall compared with interstitial cystitis morphology (1999)
    Springer
    Urological research 27 (1999), S. 454-461 
    Details
    ISSN: 1434-0879
    Keywords: Key words Cold-restraint stress ; Urinary bladder ; Interstitial cystitis ; Mast cell ; Urothelium ; Ultrastructure ; Ruthenium red ; Flow cytometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Stress is associated with many diseases of unknown aetiology. This study demonstrates the effects of cold-restraint stress on the morphology of the urinary bladder. Additionally, it compares the results obtained with the morphology of the interstitial cystitis. The animals were subjected to three hours of cold-restraint stress and then starved for 48 h. The morphology and histochemistry of the urinary bladder was investigated with light and electron microscopy. The proliferative activity was analysed via flow cytometry. Increased and degranulated mast cells in the mucosa, leucocyte infiltration in the lamina propria, vacuole formation in the urothelial cells, loose tight junction, dilated intercellular spaces and altered proliferative activity were observed in the stress group when compared with the control. The increase in the number of mast cells and especially degranulated mast cells and vacuole formation and the loose tight junction of the urothelium correlated with the histopathological findings of interstitial cystitis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002400050135
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  • 11
    Electronic Resource
    Electronic Resource
    Bunina bodies in amyotrophic lateral sclerosis on Guam: a histochemical, immunohistochemical and ultrastructural investigation (1999)
    Springer
    Acta neuropathologica 98 (1999), S. 150-156 
    Details
    ISSN: 1432-0533
    Keywords: Key words Amyotrophic lateral sclerosis ; Bunina body ; Guam ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An investigation of Bunina bodies is important when studying the pathoetiology and pathomechanisms involved in amyotrophic lateral sclerosis (ALS). It may serve as a clue essential for the study of the pathogenesis of Guamanian amyotrophic lateral sclerosis (ALS-G), and it may provide a means of answering the question of whether ALS-G is the same disease as classical ALS or a different entity. In ALS-G, however, no precise histochemical, immunohistochemical, or detailed ultrastructural examination has been published to date. To elucidate the pathological differences/similarities of Bunina bodies between classical ALS and ALS-G, we performed histochemical, immunohistochemical, topographic and ultrastructural examinations. Histochemically, hematoxylin and eosin, Masson’s trichrome, methylgreen-pyronin, phosphotungstic acid-hematoxylin, Klüver-Barrera, Bodian and periodic acid-Schiff staining were utilized. Immunohistochemical examination was performed using antibodies for cystatin C, ubiquitin, Tau-2, Cu/Zn superoxide dismutase, phosphorylated neurofilament and glial fibrillary acidic protein. Histochemical findings were consistent with those previously described for classical ALS. The immunohistochemical study showed that in ALS-G Bunina bodies were intensely labeled by an anti-cystatin C antibody. Topographic examination demonstrated that Bunina bodies were distributed in the spinal anterior horns and Clarke’s column in the spinal cord. Ultrastructurally, Bunina bodies were composed of electron-dense amorphous/ granular material accompanied by vesicular structures and neurofilaments. The results of the present study have revealed that the pathological features of Bunina bodies in ALS-G are identical to those seen in classical ALS. These findings strongly suggest that a similar degenerative process occurs in the spinal anterior horn cells in both ALS-G and classical ALS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010051063
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  • 12
    Electronic Resource
    Electronic Resource
    Familial inclusion body myopathy with desmin storage (1999)
    Springer
    Acta neuropathologica 97 (1999), S. 509-514 
    Details
    ISSN: 1432-0533
    Keywords: Key words Hereditary inclusion body myopathy ; Desmin storage myopathy ; Ultrastructure ; Immmunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report two adult familial cases of inclusion body myopathy (IBM) with desmin storage in skeletal muscle. Clinically, both patients presented late-onset, progressive, symmetrical, both proximal and distal muscle weakness. Muscle biopsy findings were identical in both cases and consisted of marked variability in fiber size, increased number of central nuclei and vacuolation involving 10% of fibers. Single or multiple vacuoles were located subsarcolemmally or in the center, and were rimmed by basophilic material. At the ultrastructural level, tubulofilamentous nuclear and cytoplasmic inclusions of 16–21 nm in diameter were frequently observed. In addition, large subsarcolemmal and central deposits composed of electron-dense granular material were present in many fibers. Immunocytochemistry revealed staining for desmin, vimentin and ubiquitin within both inclusions and vacuolated fibers. Possible structural and functional associations between these two types of muscle changes remain unclear. They may either represent two coexistent disease processes or merely reflect an abnormal form of muscle fiber degradation, with unidentifiable specificity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010051021
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  • 13
    Electronic Resource
    Electronic Resource
    The anchoring zone in the human placental amnion: bunches of oxytalan and collagen connect mesoderm and epithelium (1999)
    Springer
    Anatomy and embryology 200 (1999), S. 81-90 
    Details
    ISSN: 1432-0568
    Keywords: Key words Elastic fibre system ; Microfibrils ; Collagen type IV ; Ultrastructure ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  This study deals with the examination of the elastic fibre system as well as collagen fibrils and collagen type IV in the amnion of the human chorionic plate of uncomplicated pregnancies at term. In organs other than placenta, the elastic fibre system comprises elastic fibres, elaunin and oxytalan microfibrils. The investigation was performed by light and electron microscopy and immunocytochemistry. Abundant oxytalan fibres were present in all amnionic layers, while no elastic fibres were found. Oxytalan microfibrils formed a broad subepithelial layer and were intermingled with collagen fibrils in the subjacent compact layer and in the amnionic mesoderm. Light microscopically, bunches containing orcein-stained oxytalan and collagen-type-IV-immunostained microfibrils were seen rising from the amnionic mesoderm perpendicularly towards the epithelial layer, where they obviously inserted. It can be assumed that the subepithelial microfibrillar layer and the following compact layer form an anchoring zone between the amnionic mesoderm and the epithelium that may contribute to the maintenance of strength. The ultrastructure of the bunches clearly showed collagen fibrils mixed with oxytalan microfibrils. No collagen type I-immunostaining was found in the bunches. After pretreatment of cryostat sections with elastase, oxytalan-orcein-staining was absent, but collagen type IV-immunoreactivity was not altered. Furthermore, after oxytalan-orcein-staining resp. anti-collagen type IV incubation, all positive fibres revealed an identical morphological pattern. We propose that oxytalan and collagen type IV may represent further members of the microfibril complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004290050262
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  • 14
    Electronic Resource
    Electronic Resource
    Ultrastructural localization of phosphorylated eIF2α [eIF2α(P)] in rat dorsal hippocampus during reperfusion (1999)
    Springer
    Acta neuropathologica 98 (1999), S. 493-505 
    Details
    ISSN: 1432-0533
    Keywords: Key words Ischemia ; Protein synthesis ; Translation ; Ultrastructure ; Hippocampus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract During post-ischemic brain reperfusion there is a substantial reduction of protein synthesis in selectively vulnerable neurons. Normal protein synthesis requires a functional translation initiation complex, a key element of which is eukaryotic initiation factor 2 (eIF2), which in a complex with GTP introduces the met-tRNAi. Phosphorylation of Ser51 on the α subunit of eIF2 [eIF2α(P)] generates a competitive inhibitor of eIF2B, thereby preventing the replenishment of GTP onto eIF2, thus blocking translation initiation. It has been shown that the conditional expression of an eIF2α mutant (Asp substituted for Ser51) imitating the negative charge of Ser51 (P) induces apoptosis. During the first 10 min of post-ischemic reperfusion, there is an approximately 20-fold increase in eIF2α(P) seen in the cytoplasm of CA1 hippocampal neurons, and, by 1 h, there is also accumulation of eIF2α(P) in the nucleus. We utilized post-embedding electron microscopical immunogold methods to examine the localization of eIF2α(P) during reperfusion. Immunogold particles (10 nm) were concentrated chiefly along the rough endoplasmic reticulum and in association with the membranes of the nuclear envelope in CA1 neurons. Aggregations of gold particles in the nucleus were concentrated: (1) within and around the nucleolus, (2) associated to strands of heterochromatin, and (3) along putative nuclear filaments. The presence of eIF2α(P) in the nucleolus probably reflects its association with nascent ribosomal subunits. The β-subunit of eIF2 has a zinc finger and polylysine blocks analogous to those on other proteins that affect transcription. The association of eIF2α(P) with chromatin may have important implications for transcription.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010051115
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  • 15
    Electronic Resource
    Electronic Resource
    Structural identification and characterization of arteries and veins in the placental stem villi (1999)
    Springer
    Anatomy and embryology 199 (1999), S. 407-418 
    Details
    ISSN: 1432-0568
    Keywords: Key words Placenta ; Vascular wall ; Smooth muscle cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The vascular wall structure in the human full-term placental villi of normal pregnancy was studied by means of light and electron microscopy with an improved technique of perfusion fixation and tissue preparation. We observed 81 sections of stem villi that showed cross-sectional profiles of paired vessels in their center. Both vascular walls contained a large amount of extracellular matrix and no elastic lamina between smooth muscle cells of the media, making identification of the artery and the vein quite difficult at first sight. We then noted that the density of the smooth muscle cell population was always considerably higher in one than the other, and identified the former as artery and the latter as vein on the basis of their connection with larger arteries and veins running on the chorionic plate. Between the paired vessels, the artery had a smaller caliber than the vein, and the ratio of venous to arterial caliber was distributed from 1.0 to 2.5. The thickness of media was usually thicker in the vein than in the artery. Clusters of elastic fibers were found occasionally in the media of arteries and veins, and basement membrane-like materials were associated frequently with the elastic fibers and were distributed widely in the media as well as in the adventitia. In the veins, the smooth muscle cells of the most superficial part of the media contained well-developed rough endoplasmic reticulum and Golgi apparatus, indicating differentiation to secrete extracellular matrices. The present study revealed the difference of wall structure between arteries and veins in the placental stem villi for the first time at the ultrastructural level, and suggested differentiation of venous smooth muscle cells, possibly by some influence from the luminal side.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004290050239
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  • 16
    Electronic Resource
    Electronic Resource
    Immunohistochemical, conventional and immunoelectron microscopical characteristics of periodic acid-Schiff-positive granules in the mouse brain (1999)
    Springer
    Acta neuropathologica 98 (1999), S. 31-38 
    Details
    ISSN: 1432-0533
    Keywords: Key words Polyglucosan body ; Periodic ; acid-Schiff-positive granules ; Mouse brain ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Periodic acid-Schiff-positive granules (PGs) appear in the mouse brains in relation to advancing age. The exact location and pathophysiological significance of PGs, however, are not fully understood. The incidence, staining properties, and topographical distributions of PGs in the brains of 17 AKR mice ranging in age from 7 to 18 months were examined histochemically and immunohistochemically using antibody KM279 raised against a polyglucosan. In addition, to define the precise site of PG formation, we investigated the brains of 4 AKR mice of 24 months of age using conventional and immunoelectron microscopy. PGs were seen in all mice examined and the levels were increased with age. The PGs were located predominantly in the hippocampus and, to a lesser extent, in the cerebellum and olfactory bulb. Immunohistochemically, PGs in the hippocampus and cerebellum were labeled uniformly with KM279. On immunoelectron microscopy with this monoclonal antibody, the fibrillar or membranous structures corresponding to PGs seen using light microscopy were labeled specifically with gold particles. With conventional electron microscopy, fibrillar or membranous structures were seen along with synaptic vesicles and dense-core granules. Moreover, around the cells containing PGs, a few synaptic junctions with neighboring cells were observed, indicating that the cells contributing to formation of PGs were neuronal cells. The positive immunoreactivity of AKR mouse PGs for the antibody KM279 suggests that the PGs and similar structures in other species may share a common antigenicity. Thus, it is assumed that PGs in AKR mice might result from some abnormalities in glucose metabolism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010051048
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  • 17
    Electronic Resource
    Electronic Resource
    The visualization of a new class of traumatically injured axons through the use of a modified method of microwave antigen retrieval (1999)
    Springer
    Acta neuropathologica 97 (1999), S. 335-345 
    Details
    ISSN: 1432-0533
    Keywords: Key words Amyloid precursor protein ; immunoreactivity ; Axonal injury ; Microwave antigen retrieval ; Traumatic brain injury ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Antibodies to the amyloid precursor proteins (APP) have become routine markers for detecting traumatically induced axonal injury (AI) in animals and man. Unfortunately, the techniques used to visualize these proteins are not compatible with routine electron microscopic (EM) analysis. In the current communication, we describe a method for the ultrastructural visualization of antibodies to APP and, using this method, we identify a previously unrecognized population of traumatically injured axons. Rats were subjected to an impact acceleration traumatic brain injury and allowed to survive 30 min to 3 h postinjury. The animals were then perfused, their brains sectioned on a vibratome and the sections prepared for immunocytochemistry using a computer-controlled microwave capable of temperature regulation. The use of temperature-controlled microwave energy unmasked APP antigenic epitopes without sacrificing ultrastructural detail. The APP antibody was found in two distinct populations of reactive axons that differed in size, morphology, location, and temporal progression. Comparable to previous descriptions, one population showed traumatically related reactive changes that led to swelling and disconnection. The other population, however, revealed unanticipated changes reflected in nodal and paranodal swelling of small continuous fibers that showed no evidence of disconnection during the time periods assessed. These studies provide new insight into the complexity of the pathobiology of AI, while describing a novel approach for enhancing APP immunoreactivity at the EM level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050996
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  • 18
    Electronic Resource
    Electronic Resource
    Synaptology and ultrastructural characteristics of laryngeal cricothyroid and posterior cricoarytenoid motoneurons in the nucleus ambiguus of the rat (1999)
    Springer
    Anatomy and embryology 200 (1999), S. 301-311 
    Details
    ISSN: 1432-0568
    Keywords: Key words Intrinsic laryngeal motoneurons ; Cholera toxin HRP ; Ultrastructure ; Swallowing ; Respiration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The laryngeal motoneurons innervating the cricothyroid muscle (CT) are located in the semicompact formation just ventral to the rostral part of the compact formation of the nucleus ambiguus. The motoneurons innervating the posterior cricoarytenoid muscle (PCA) are located in the loose formation. We retrogradely labeled the CT and the PCA motoneurons using cholera toxin subunit B-conjugated horseradish peroxidase, and determined the ultrastructure and synaptic organization of these neurons. The CT and the PCA motoneurons had the appearance of α-motoneurons, i.e., large, oval or polygonal cells containing well-developed organelles and a prominent spherical nucleus. Two kinds of neurons were recognized among the PCA motoneurons. The one (PCA-A) was significantly smaller than the other (PCA-B). The average number of axosomatic terminals in a section was significantly largest in the PCA-B (56.6), smaller in the PCA-A (36.0), and smallest in the CT (32.3) neurons. Most of the axosomatic terminals (64.7%) contained pleomorphic vesicles and made symmetric synaptic contacts (Gray’s type II) with the PCA-A neurons, while more than 60% contained round vesicles with asymmetric synaptic contacts (Gray’s type I) in the CT (69.5%) and the PCA-B (60.6%) neurons. A few terminals associated with subsurface cisterns were present on all laryngeal motoneurons. These results indicated that the CT motoneurons may receive mostly excitatory terminals, whereas the PCA muscle may be regulated by neurons having many inhibitory terminals, and neurons having many excitatory terminals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004290050281
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  • 19
    Electronic Resource
    Electronic Resource
    Light and electron microscopic immunohistochemical observations of p75 nerve growth factor receptor-immunoreactive dermal nerves in prurigo nodularis (1999)
    Springer
    Archives of dermatological research 291 (1999), S. 14-21 
    Details
    ISSN: 1432-069X
    Keywords: Key words p75 nerve growth factor receptor ; (p75 NGFr) ; Immunoreactivity ; Ultrastructure ; Prurigo nodularis ; Nerve fiber
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Prurigo nodularis is an inflammatory skin disease characterized by neurohyperplasia. Neurotrophins and their receptors play a critical role in nerve growth, differentiation, maturation and maintenance, including cutaneous nerve fiber growth and innervation. They may also be responsible for events related to the growth and differentiation control of keratinocytes. To explore the exact distribution of the p75 low-affinity nerve growth factor receptor (p75 NGFr) in the cutaneous nerve components, p75 NGFr immunofluorescence as well as ultrastructural immunohistochemical studies were performed on prurigo nodularis lesional skin and normal human skin samples. The immunofluorescence results revealed that nerve fibers and bundles were increased in number and size in lesional upper dermis with stronger p75 NGFr immunoreactivity than in the corresponding normal tissue. At the ultrastructural level, a lot of nerve fibers clustered together in the prurigo nodularis dermal tissue. The axons were enlarged and branched, but the axons themselves seldom showed any NGFr immunoreactivity. The Schwann cell bodies were extended and irregularly shaped, and tended to separate into many branches enveloping the axons. The Schwann cell membrane showed strong p75 NGFr immunoreactivity. The perineurium cells also revealed strong p75 NGFr immunoreactivity. The Schwann cells inside the perineurium were less p75 NGFr-immunoreactive than those outside the perineurium. The membrane of certain basal keratinocytes showed NGFr immunoreactivity as well. The present results indicate that overexpression of p75 NGFr in Schwann cells and perineurium cells could contribute to the neurohyperplasia in prurigo nodularis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004030050378
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  • 20
    Electronic Resource
    Electronic Resource
    Larva-adult relationships in an ancestral dipteran: A re-examination of sensillar pathways across the antenna and leg anlagen of Chaoborus crystallinus (DeGeer, 1776; Chaoboridae) (1999)
    Springer
    Development genes and evolution 209 (1999), S. 103-112 
    Details
    ISSN: 1432-041X
    Keywords: Key words Imaginal disc ; Axonal trajectories ; Ultrastructure ; Chaoborus (Insecta ; Diptera)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  In one of his classical studies on insect metamorphosis, Weismann compared the imaginal anlagen of the ancestral phantom midge, Chaoborus, with those of advanced brachycerans. We have expanded his findings on the relationships between larval and imaginal organs using electron microscopy and cobalt backfilling of the antenna and leg anlagen and the axonal trajectories of corresponding larval sensilla. We show that both primordia are confluent with the larval antennae and ”leg” sensilla (an ancestral Keilin organ), respectively. These fully developed larval organs represent the distal tips of the imaginal anlagen rather than separate cell clusters. The axons of the larval antenna and leg sensilla project across the corresponding anlagen to their target neuromeres within the central nervous system (CNS). Within the discs, nerves composed of these larval axons, developing afferent fibres and efferences ascending from the CNS are found. Both the structure of the primordia and the axonal trajectories thus relate the situation found in advanced brachycerans with that seen in more ancestral insects. In addition, the larval antennae, legs, wings and even the eyes possess very similar afferent pioneer trajectories supporting the idea that the described pattern is generally used in the ontogeny of sensory systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004270050232
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  • 21
    Electronic Resource
    Electronic Resource
    Megasporogenesis in Arabidopsis thaliana L.: an ultrastructural study (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 99-109 
    Details
    ISSN: 1432-2145
    Keywords: Key words Arabidopsis thaliana ; Megasporogenesis ; Meiosis ; Ultrastructure ; Cellular polarity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  In this study, megasporogenesis of the plant model Arabidopsis thaliana was investigated by electron microscopy for the first time. The data described here could constitute a reference for future investigations of Arabidopsis mutants. During the beginning of meiosis the megaspore mother cell shows a polarity created by unequal distribution of organelles in the cytoplasm. Plastids accumulate in the chalazal region and long parallel saccules of endoplasmic reticulum, small vacuoles and some dictyosomes are found in the micropylar region. Plasmodesmata are abundant in the chalazal cell wall. The nucleus is almost centrally localized and contains a prominent excentric nucleolus and numerous typical synaptonemal complexes. After the second division of meiosis the four megaspores are separated by thin cell walls crossed by numerous plasmodesmata and do not show significant cellular organization. The young functional megaspore is characterized by a large nucleus and a large granular nucleolus. The cytoplasm is very electron dense due to the abundance of free ribosomes and contains the following randomly distributed organelles: mitochondria, a few short saccules of endoplasmic reticulum, dictyosomes and undifferentiated plastids. However, there is no apparent polarity, except for the distribution of some small vacuoles which are more abundant in the micropylar region of the cell. The degenerating megaspores are extremely electron dense and do not show any substructure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050178
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  • 22
    Electronic Resource
    Electronic Resource
    Studies of lectin receptors of rat microglia in culture: receptor distribution and internalization (1999)
    Springer
    Experimental brain research 124 (1999), S. 89-99 
    Details
    ISSN: 1432-1106
    Keywords: Key words Microglial culture ; Brain macrophages ; Isolectin ; Ultrastructure ; Intracellular pathway
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The present study examined the lectin labeling of diverse morphological forms of microglia in culture. Similar to amoeboid microglial cells in vivo, polymorphic microglia showed lectin labeling at their plasma membranes, as well as in a few cytoplasmic vesicles and vacuoles. This labeling pattern was observed in cultured microglia incubated with isolectin at 4°C for 30 min. Five minutes after the temperature was raised to 37°C, the surface lectin receptors appeared to be internalized, as shown by the occurrence of many subsurface lectin-labeled vesicles, vacuoles and tubule-like structures. With longer incubation (up to 1–2 h at 37°C), many lysosomes and a few trans-Golgi saccules and associated lysosome-like structures became labeled. Concomitant with these changes was a reduction of lectin labeling at the plasma, with labeling having vanished in most of the cells after 1–2 h of incubation. By 24 h, only a few cells retained surface lectin labeling. It appears, therefore, that irrespective of morphology, lectin labeling (including its intracellular pathway) of microglia in culture parallels that of amoeboid microglia in vivo. This would offer a useful model for the study of lectin turnover in microglia and help to explain the roles of such receptors in microglial differentiation and function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002210050603
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  • 23
    Electronic Resource
    Electronic Resource
    Isolation and characterization of a Clostridium sp. with cinnamoyl esterase activity and unusual cell envelope ultrastructure (1999)
    Springer
    Archives of microbiology 172 (1999), S. 139-149 
    Details
    ISSN: 1432-072X
    Keywords: Key wordsClostridium xylanolyticum ; Cinnamic acid ; Esterase ; Lignocellulose ; Sporogenesis ; Ultrastructure ; Cell envelope
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Microorganisms that hydrolyse the ester linkages between phenolic acids and polysaccharides in plant cell walls are potential sources of enzymes for the degradation of lignocellulosic waste. An anaerobic, mesophilic, spore-forming, xylanolytic bacterium with high hydroxy cinnamic acid esterase activity was isolated from the gut of the grass-eating termite Tumilitermes pastinator. The bacterium was motile and rod-shaped, stained gram-positive, had an eight-layered cell envelope, and formed endospores. Phylogenetic analysis based on 16S rRNA indicated that the bacterium is closely related to Clostridium xylanolyticum and is grouped with polysaccharolytic strains of clostridia. A wide range of carbohydrates were fermented, and growth was stimulated by either xylan or cellobiose as substrates. The bacterium hydrolysed and then hydrogenated the hydroxy cinnamic acids (ferulic and p-coumaric acids), which are esterified to arabinoxylan in plant cell walls. Three cytoplasmic enzymes with hydroxy cinnamic acid esterase activity were identified using non-denaturing gel electrophoresis. This bacterium possesses an unusual multilayered cell envelope in which both leaflets of the cytoplasmic membrane, the peptidoglycan layer and the S layer are clearly discernible. The fate of all these components was easily followed throughout the endospore formation process. The peptidoglycan component persisted during the entire morphogenesis. It was seen to enter the septum and to pass with the engulfing membranes to surround the prespore. It eventually expanded to form the cortex, verification for the peptidoglycan origin of the cortex. Sporogenic vesicles, which are derived from the cell wall peptidoglycan, were associated with the engulfment process. Spore coat fragments appeared early, in stage II, though spore coat formation was not complete until after cortex formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002030050753
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  • 24
    Electronic Resource
    Electronic Resource
    Articular chondrocytes and synoviocytes in a co-culture system: influence on reactive oxygen species-induced cytotoxicity and lipid peroxidation (1999)
    Springer
    Cell & tissue research 296 (1999), S. 555-563 
    Details
    ISSN: 1432-0878
    Keywords: Key words Chondrocyte ; Synoviocyte ; Co-culture ; Proliferation ; Lipid peroxidation ; Cytotoxicity ; Ultrastructure ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Objective: A new co-culture system of rat articular chondrocytes and synoviocytes (HIG-82; cell line) was incubated with phorbol myristate acetate (PMA), H2O2 or a combination of Fe2+ and ascorbic acid to simulate inflammation-like radical attacks in articular joints. Methods: Chondrocytes were characterized by immunocytochemistry against collagen type II, transmission electron (TEM) and light microscopy. Lipid peroxidation was investigated by measuring thiobarbituric-acid-reactive material in the supernatants, cytotoxicity by determining release of lactate dehydrogenase and proliferation by measuring [3H]thymidine incorporation, culture protein and DNA. Results: PMA or Fe2+ and ascorbic acid induced lipid peroxidation in chondrocytes and synoviocytes that was decreased significantly in co-cultures. PMA and H2O2 dose dependently induced release of lactate dehydrogenase in chondrocytes, which was lowered in co-cultures or in previously co-cultured chondrocytes to a nearly basal level. In contrast, conditioned media of synoviocyte cultures showed no lowering effect on the radical-induced toxicity. Protection against H2O2-induced damage of cellular membranes by co-culturing was also shown by TEM. Synoviocytes released chondrocyte-stimulating growth factors spontaneously without previous interaction. Conclusion: Chondrocytes establish protective mechanisms against reactive oxygen species via an interaction with synoviocytes. Our co-culture model presents a possible way to study mechanisms of inflammation in articular joints under defined conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051317
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  • 25
    Electronic Resource
    Electronic Resource
    Ultrastructure and distribution dynamics of chloride cells in tilapia larvae in fresh water and sea water (1999)
    Springer
    Cell & tissue research 297 (1999), S. 119-130 
    Details
    ISSN: 1432-0878
    Keywords: Key words Chloride cells (mitochondria-rich cells) ; Teleost larvae ; Osmoregulation ; Immunohistochemistry ; Quantification ; Ultrastructure ; Oreochromis mossambicus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Integumental and branchial chloride cells of tilapia larvae (Oreochromis mossambicus) were studied at the light-microscopical and ultrastructural level. Total numbers and distribution of chloride cells were quantified after immunostaining of cross sections of the entire larvae with an antibody against the α-subunit of Na+/K+-ATPase. The majority (66%) of Na+/K+-ATPase-immunoreactive (ir) cells, i.e. chloride cells, of freshwater tilapia larvae were located extrabranchially up to 48 h after hatching. Five days after hatching, the majority (80%) of chloride cells were found in the buccal cavity. Transfer of 24-h-old larvae to 20% sea water speeded up this process; 24 h after transfer (i.e. 48 h after hatching), the majority (59%) of chloride cells were located in the buccal cavity. The branchial chloride cell population of 24-h- and 120-h-old larvae consisted of immature, mature, apoptotic and necrotic chloride cells. However, relatively more immature chloride cells were observed in freshwater larvae (42–63%) than in (previously studied) freshwater adults (21%), illustrating the developmental state of the gills. After transfer to sea water, the incidence of degenerative chloride cells did not change. Furthermore, the incidence of immature cells had decreased and a new subtype of chloride cells, the ”mitochondria-poor” cells, appeared more frequently. These mitochondria-poor chloride cells were characterised by an abundant tubular system and relatively few mitochondria, which were aligned at the border or concentrated in one part of the cytoplasm. Most of these cells did not contact the water. The function of their enhanced appearance after seawater transfer is unknown.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051339
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  • 26
    Electronic Resource
    Electronic Resource
    Peripheral synapses at identifiable mechanosensory neurons in the spider Cupiennius salei : synapsin-like immunoreactivity (1999)
    Springer
    Cell & tissue research 295 (1999), S. 13-19 
    Details
    ISSN: 1432-0878
    Keywords: Key words Mechanoreceptors ; Synaptic proteins ; Histochemistry ; Ultrastructure ; Slit sensilla ; Hair sensilla ; Cupiennius salei (Chelicerata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Indirect immunocytochemical tests were used at the light- and electron-microscopic levels to investigate peripheral chemical synapses in identified sensory neurons of two types of cuticular mechanosensors in the spider Cupiennius salei Keys.: (1) in the lyriform slit-sense organ VS-3 (comprising 7–8 cuticular slits, each innervated by 2 bipolar sensory neurons) and (2) in tactile hair sensilla (each supplied with 3 bipolar sensory cells). All these neurons are mechanosensitive. Application of a monoclonal antibody against Drosophila synapsin revealed clear punctate immunofluorescence in whole-mount preparations of both mechanoreceptor types. The size and overall distribution of immunoreactive puncta suggested that these were labeled presynaptic sites. Immunofluorescent puncta were 0.5–6.8 μm long and located 0.5–6.6 μm apart from each other. They were concentrated at the initial axon segments of the sensory neurons, while the somata and the dendritic regions showed fewer puncta. Western blot analysis with the same synapsin antibody against samples of spider sensory hypodermis and against samples from the central nervous system revealed a characteristic doublet band at 72 kDa and 75 kDa, corresponding to the apparent molecular mass of synapsin in Drosophila and in mammals. Conventional transmissionelectron-microscopic staining demonstrated that numerous chemical synapses (with at least 2 vesicle types) were present at these mechanosensory neurons and their surrounding glial sheath. The distribution of these synapses corresponded to our immunofluorescence results.Ultrastructural examination of anti-synapsin-stained neurons confirmed that reaction product was associated with synaptic vesicles. We assume that the peripheral synaptic contacts originate from efferents that could exert a complex modulatory influence on mechanosensory activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051208
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  • 27
    Electronic Resource
    Electronic Resource
    Androgen-induced changes in Leydig cell ultrastructure and steroidogenesis in juvenile African catfish, Clarias gariepinus (1999)
    Springer
    Cell & tissue research 297 (1999), S. 291-299 
    Details
    ISSN: 1432-0878
    Keywords: Key words Teleost fish ; Puberty ; Testes ; Sex steroids ; Ultrastructure ; Steroidogenesis ; Clarias gariepinus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The present report focuses on the mechanism(s) involved in the steroid-induced decrease of androgen production in immature African catfish testes that was observed in previous studies. Juvenile animals were implanted with Silastic pellets containing different 11-oxygenated androgens (11-ketotestosterone, KT; 11β- hydroxyandrostenedione, OHA; 11-ketoandrostenedione, KA), testosterone (T) or estradiol-17β (E2). Control groups received steroid-free pellets. Two weeks later, testis tissue fragments were either incubated with increasing concentrations of catfish luteinizing hormone (LH), or incubated with [3H]-pregnenolone ([3H]-P5) or [3H]-androstenedione ([3H]-A). Tissue fragments were also prepared for the quantitative assessment of Leydig cell morphology. Most of the parameters studied were not affected significantly by implantation of E2. Implantation of all androgens inhibited both the basal and the LH-stimulated androgen secretory capacity in vitro. This was associated with a reduced size of the Leydig cells and loss of half of their mitochondria. The studies on the metabolism of tritiated steroid hormones indicated that steroidogenic steps prior to 11β-hydroxylation, probably C17–20 lyase activity, were affected by all androgens. Although the effects of 11-oxygenated androgens and T on Leydig cells were mostly similar, previous work showed that only the 11-oxygenated androgens stimulated spermatogenesis, suggesting that distinct mechanisms of action are used by 11-oxygenated androgens and T. These mechanisms, however, seem to merge on the same target(s) to impair Leydig cell androgen production. Such a negative feedback mechanism may be of relevance in the context of the decline in androgen secretion per milligram testis tissue that accompanies the first wave of spermatogenesis in pubertal African catfish.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051357
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  • 28
    Electronic Resource
    Electronic Resource
    The distribution and ultrastructure of class II MHC-positive cells in human dental pulp (1999)
    Springer
    Cell & tissue research 295 (1999), S. 151-158 
    Details
    ISSN: 1432-0878
    Keywords: Key words Class II MHC-positive cells ; Human leukocyte antigen-DR ; Dental pulp ; Dendritic cells ; Macrophages ; Ultrastructure ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution and ultrastructure of class II major histocompatibility complex (MHC)-positive cells were investigated in human dental pulp, employing immunohistochemistry using an anti-human leukocyte antigen (HLA)-DR-monoclonal antibody. HLA-DR-immunopositive cells, appearing spindle-like or dendritic in profile, were densely distributed throughout the dental pulp. Under the electron microscope, these cells exhibited various sizes of vesicles containing clear or opaque contents, multivesicular bodies and characteristic fine tubulovesicular structures in their cytoplasm. Some reactive cells possessed coated pits and vesicles including electron-dense materials, indicating an active endocytosis. At the periphery of the pulp tissue, the HLA-DR-immunopositive cells were predominantly situated in the subodontoblastic layer, with some located in the odontoblast layer and/or predentin and extending their cytoplasmic processes into the dentinal tubules. Cell processes of these cells occasionally made contact with several odontoblast processes in the same way as the nerve fibers in the predentin. These cells never contained the typical phagosomes frequently observed in the HLA-DR-immunoreactive macrophages in the subodontoblastic layer and the pulp core. The results suggest that the HLA-DR-immunopositive cells in the odontoblast layer and/or predentin have some regulatory function on the odontoblasts under physiological conditions, in addition to their involvement in the initial defense reaction after tooth injury.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051221
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  • 29
    Electronic Resource
    Electronic Resource
    Effect of high-level oxygen exposure on the peroxidase activity and the neuromelanin-like pigment content of the nerve net in the earthworm, Lumbricus terrestris (1999)
    Springer
    Cell & tissue research 295 (1999), S. 349-354 
    Details
    ISSN: 1432-0878
    Keywords: Key words Neuromelanin ; Neuron ; Peroxidase ; Oxygen metabolism ; High-definition light microscopy ; Electron microscopy ; Ultrastructure ; Cytochemistry ; Substantia nigra ; Lumbricusterrestris (Annelida)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Histochemical examination of 1-μm tissue sections from the dorsal nerve plexus of the earthworm, Lumbricus terrestris, reveals multiple brown intraneuronal granules. These granules contain material morphologically and histochemically consistent with neuromelanin. When viewed with transmission electron microscopy, these were seen as single membrane-enclosed biphasic granules with diameters of 370–730 nm. Exposure of L. terrestris to high-level environmental oxygen resulted in an increase in the number of neuromelanin-like pigment granules within the neurons of the circular muscle layer. As measured by ortho-phenylenediamine hydrochloride, the endogenous peroxidase activity of extracts from worms incubated in high-level environmental oxygen was 51% more than controls. The endogenous peroxidase activity was localized in situ with 3,3-diaminobenzidine (DAB) and was found to increase in and around the neuromelanin-like pigment-containing neurons within the circular muscle layer. These studies suggest that the nerve net of L. terrestris may serve as a model to study the role of neuromelanin production in oxidative stress and its relationship to endogenous peroxidases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051241
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  • 30
    Electronic Resource
    Electronic Resource
    Survival of rat MCH (melanin-concentrating hormone) neurons in hypothalamus slice culture: histological, pharmacological and molecular studies (1999)
    Springer
    Cell & tissue research 297 (1999), S. 23-33 
    Details
    ISSN: 1432-0878
    Keywords: Key words Melanin-concentrating hormone neurons ; Lateral hypothalamic slice culture ; Immunocytochemistry ; Ultrastructure ; In situ hybridization ; Competitive RT-PCR ; Leptin assay ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Hypothalamic slices containing the lateral hypothalamic area (LHA) were prepared from 6- to 8-day-old rats and maintained in stationary culture for up to 35 days in order to analyse how well the melanin-concentrating hormone (MCH) neurons survived. As previously reported for other brain areas, this method yielded a long-term well-preserved organotypic organization. Light- and electron-microscopic investigations showed that differentiation continued and that synaptic contacts developed in vitro. After a period of elimination of damaged cells and fibres, most of the remaining neurons and glial cells retained a normal morphology throughout the culture period. MCH neurons, in particular, survived well as attested by the strong immunocytochemical and in situ hybridization signals still observed after several weeks. In a comparison with the day of explantation, competitive reverse transcription/polymerase chain reaction demonstrated the remarkable stability of the level of MCH mRNA at least until the 20th day in culture; after 30 days, the clear decrease in this level seemed to be correlated with a loss of MCH neurons, rather than with a decrease in MCH expression. After 10 days of culture, the incubation of slices in the presence of the hormone leptin (50 ng/ml) resulted in a strong decrease of MCH gene expression, suggesting that MCH neurons retained their physiological properties. Thus, the LHA slice stationary culture, especially between one and three weeks (i.e. after tissue stabilization and before extensive cell loss), appears to be a suitable method for physiological and pharmacological studies of these neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051330
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  • 31
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    Electronic Resource
    Effects of reserpine on ECL-cell ultrastructure and histamine compartmentalization in the rat stomach (1999)
    Springer
    Cell & tissue research 295 (1999), S. 131-140 
    Details
    ISSN: 1432-0878
    Keywords: Key words ECL cells ; Gastrin ; Reserpine ; Organelles ; Ultrastructure ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The histamine-storing ECL cells in the stomach play a key role in the control of acid secretion. They contain granules, secretory vesicles and microvesicles, and sustained gastrin stimulation results in the additional formation of vacuoles and lipofuscin bodies. The cells are rich in the vesicle monoamine transporter type-2 (VMAT-2), which can be inhibited by reserpine. The present study examines the effect of reserpine on ECL-cell ultrastructure and histamine compartmentalization. Rats received reserpine and/or gastrin. Reserpine was given twice by the intraperitoneal route (25 mg/kg once daily). Gastrin-17 was given by subcutaneous infusion (5 nmol/kg/h), starting at the time of the first reserpine injection and continuing for 4 days when the rats were killed. At this stage, histamine in the oxyntic mucosa was unaffected by reserpine but elevated by gastrin. Immunocytochemical analysis (confocal microscopy) showed ECL-cell histamine in control and gastrin-treated rats to be localized in cytoplasmic organelles (e.g., secretory vesicles). After treatment with reserpine alone or reserpine+gastrin, ECL-cell histamine occurred mainly in the cytosol. Planimetric analysis (electron microscopy) of ECL cells showed reserpine to increase the number, size and volume density of the granules and to reduce the size and volume density of the secretory vesicles. Gastrin reduced the number and volume density of granules and secretory vesicles, increased the number and volume density of microvesicles and caused vacuoles and lipofuscin bodies to appear. Reserpine+gastrin increased the number, volume density and size of the granules. Reserpine prevented the effects of gastrin on secretory vesicles, vacuoles and microvesicles, but did not prevent the development of lipofuscin. Our findings are in line with the views: (1) that preformed cytosolic histamine is taken up by granules/secretory vesicles via VMAT-2, that histamine is instrumental in the transformation of granules into secretory vesicles and in their consequent enlargement and (2) that vacuoles are formed by the fusion of large secretory vesicles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051219
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  • 32
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    Electronic Resource
    Structure and function of the human oocyte-cumulus-corona cell complex before and after ovulation (1999)
    Springer
    Protoplasma 206 (1999), S. 270-277 
    Details
    ISSN: 1615-6102
    Keywords: Cumulus oophorus ; Ovarian follicle ; Fertilization ; Ultrastructure ; Immunocytochemistry ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The fine structure of the human cumulus oophorus has been reviewed on the basis of scanning and transmission electron microscopic observations as well as of immunofluorescence data. Tissues sampled from preovulatory ovarian follicles and cumulus-enclosed oocytes and fertilized eggs (collected from the oviduct or obtained during in vitro fertilization procedures) have been evaluated from a microtopographic and morphodynamic point of view in order to better clarify the possible role of this population of cells. In particular, the following aspects have been studied and discussed: the presence of multiple close contacts (modulated by the interposition of the zona pellucida) between the oocyte surface and the long microvillous evaginations projecting from the inner aspect of corona cells surface (through these structures the intraovarian cumulus oophorus may control oocyte growth and metabolism up until the time of ovulation); the occurrence of different subpopulations of cells (steroid-synthetic cells, cells producing adhesive proteins, leukocytes, macrophages) in the postovulatory, extraovarian cumulus oophorus surrounding oocytes, zygotes and early developing embryos. All these elements found in the cumulus mass may positively act, through their paracrine activities, on the chemical composition of the microenvironment in which fertilization occurs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01288215
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  • 33
    Electronic Resource
    Electronic Resource
    Ultrastructural study of the relationship between generative and vegetative cells inMagnolia ×soulangeana Soul.-Bod. pollen grains (1999)
    Springer
    Protoplasma 206 (1999), S. 87-96 
    Details
    ISSN: 1615-6102
    Keywords: Plasmalemmic cord ; Pollen grain ; Ultrastructure ; Magnolia ×soulangeana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary InMagnolia ×soulangeana pollen grains the generative cell (GC) does not become totally free within the vegetative cell (VC), at least until the pollen tube emergence. Due to a deviation in its detachment process from the sporoderm, the opposing ends of the VC plasmalemma do not fuse themselves when the GC moves away from the intine. Consequently, the interplasmalemmic space surrounding the GC does not become isolated but rather maintains continuity with the sporoderm through a complex formation that we have called plasmalemmic cord. The real existence of this formation was confirmed through serial sectioning showing the plasmalemmic cord to consist of the VC plasmalemma. In its initial portion it is occupied by a reasonably accentuated wall ingrowth of the inner layer of the intine (intine 3). In the remainder portion, neither of the cytochemical tests used in this work have revealed the presence of a significant amount of wall material. However, ultrathin sections of samples processed either chemically or by cryofixation showed the existence of an intricate system of tubules and vesicles, some of which are evaginations of the VC plasmalemma. The hypothesis that the plasmalemmic cord may have a role in the complex interactions between the two pollen cells is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279255
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  • 34
    Electronic Resource
    Electronic Resource
    Anatomical and ultrastructural changes of the floral nectary ofPisum sativum L. during flower development (1999)
    Springer
    Protoplasma 206 (1999), S. 57-72 
    Details
    ISSN: 1615-6102
    Keywords: Anatomy ; Floral nectary ; Modified stomata ; Phloem ; Pisum sativum ; Stereology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The floral nectary ofPisum sativum L. is situated on the receptacle at the base of the gynoecium. The gland receives phloem alone which departed the vascular bundles supplying the staminal column. Throughout the nectary, only the companion cells of the phloem exhibited wall ingrowths typical of transfer cells. Modified stomata on the nectary surface served as exits for nectar, but stomatal pores developed well before the commencement of secretion. Furthermore, stomatal pores on the nectary usually closed by occlusion, not by guard-cell movements. Pore occlusion was detected most frequently in post-secretory and secretory glands, and less commonly in pre-secretory nectaries. A quantitative stereological study revealed few changes in nectary fine structure between buds, flowers secreting nectar, and post-secretory flowers. Dissolution of abundant starch grains in plastids of subepidermal secretory cells when secretion commenced suggests that starch is a precursor of nectar carbohydrate production. Throughout nectary development, mitochondria were consistently the most plentiful organelle in both epidermal and subepidermal cells, and in addition to the relative paucity of dictyosomes, endoplasmic reticulum, and their associated vesicles, the evidence suggests that floral nectar secretion inP. sativum is an energy-requiring (eccrine) process, rather that granulocrine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279253
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  • 35
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    Electronic Resource
    Ultrastructural features of the myocardium of children with dilated cardiomyopathy (1999)
    Springer
    Heart and vessels 14 (1999), S. 52-56 
    Details
    ISSN: 1615-2573
    Keywords: Endomyocardial biopsy ; Dilated cardiomyopathy ; Children ; Ultrastructure ; Basal lamina layering of capillary
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We analyzed the electron-microscopic features of endomyocardial biopsy from pediatric patients with dilated cardiomyopathy (DCM). The specimens examined were taken from the right ventricle of ten patients aged from 2 to 15 years (mean 9.7 years). Biopsy specimens from eight patients with congenital heart disease (tetralogy of Fallot), aged from 3 to 12 (mean 7.3 years), and ten adult patients with DCM, aged from 32 to 60 (mean 45 years), were also examined. Patients considered to have endocardial fibroelastosis, arrhythmogenic right ventricular cardiomyopathy, specific cardiomyopathy, or coronary heart disease were excluded from this study. Specimens from pediatric patients with DCM showed various degrees of ultrastructural abnormalities of myocytes, including myofibrillar fragmentation, mitochondrial abnormalities, and intracellular edema. The ultrastructurally determined contractility failure index based on the severity of myocardial degeneration at the electronmicroscopic level was 4.9 ± 1.1. This value was significantly higher than that in patients with tetralogy of Fallot (0.9 ± 0.6,P 〈 0.001) but was not significantly different from that in adult patients with DCM (6.1 ± 2.6). The index of pediatric patients with DCM who died within 3 years was high (6.0 ± 0.8). Basal lamina layering of a capillary (BLL) in the myocardium was revealed in 1 of the 10 (10%) pediatric patients with DCM and in 6 of the 10 (60%) adult patients with DCM (P 〈 0.05). No BLL was noted in the patients with tetralogy of Fallot. These findings may be related to the pathogenesis of DCM in children and adults.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02481742
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  • 36
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    Electronic Resource
    Distribution and transmission of endosymbiotic microorganisms in the oocytes of the pig louse,Haematopinus suis (L.) (Insecta: Phthiraptera) (1999)
    Springer
    Protoplasma 209 (1999), S. 207-213 
    Details
    ISSN: 1615-6102
    Keywords: Endosymbiont ; Mycetocyte ; Mycetome ; Oocyte ; Transovarial transmission ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary All anoplurans live symbiotically with prokaryotic microorganisms hosted in specialized cells, termed mycetocytes. In nymphs and males mycetocytes are distributed between midgut epithelial cells. In females, besides the midgut, mycetocytes are found in the reproductive organs where they are located at the base of ovarioles in contact with lateral oviducts. The mycetocyte-associated symbionts are transmitted from one generation to the next transovarially. Here, the results of histological and ultrastructural studies on the distribution and transmission of symbiotic microorganisms within the ovaries of the anopluranHaematopinus suis are presented. Interestingly, during advanced oogenesis (i.e., choriogenesis) of this species all symbionts are localized extracellularly and form a tight mass located at the posterior pole of the oocyte just below the hydropyle. In insects studied so far, such localization of transovarially transmitted microorganisms has been reported only in the closely related speciesHaematopinus eurysternus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01453449
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  • 37
    Electronic Resource
    Electronic Resource
    Chemische Synthese und gaschromatographischer Nachweis von Alkylglucuroniden (1999)
    Springer
    Rechtsmedizin 9 (1999), S. 184-189 
    Details
    ISSN: 1434-5196
    Keywords: Key words Ethyl glucuronide ; Congeners of alcoholic beverages ; Alkyl glucuronide ; Gas chromatography ; Mass spectrometry ; Schlüsselwörter Ethylglucuronid ; Begleitstoffe ; Alkylglucuronid ; Gaschromatographie ; Massenspektrometrie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Description / Table of Contents: Zusammenfassung Es wird die chemische Synthese von Alkylglucuroniden beschrieben, die nach Konsum von begleitstoffhaltigen Getränken als Metaboliten im Urin erscheinen. Von folgenden Alkoholen wurden die Glucuronide synthetisiert: Methanol, d5-Ethanol, Propanol, Isopropanol, Butanol, Isobutanol, R-(–)-2-Butanol, S-(+)-2-Butanol, Isopentanol, S-(–)-2-Methylbutanol. Die Retentionsindizes der Acetyl-, Pentafluorpropyl(PFP)- und Trimethylsilyl(TMS)-derivate werden mitgeteilt und der Einfluß der chemischen Struktur auf den RI-Wert diskutiert. Die Massenspektren der homologen Derivate erwiesen sich als sehr ähnlich, aber einige Fragmente sind spezifisch für die Kettenlänge der Alkylgruppe und können zur Identifizierung und Quantifizierung der Glucuronide in Urinproben herangezogen werden.
    Notes: Abstract The chemical synthesis of alkyl glucuronides, which appear as metabolites in urine after the consumption of beverages containing congeners of ethanol, is described. Glucuronides of the following alcohols were synthesized: methanol, d5-ethanol, propanol, isopropanol, butanol, isobutanol, R-(–)-2-butanol, S-(+)-2-butanol, isopentanol and S-(–)-2-methylbutanol. The retention indices of acetyl, pentafluorpropyl (PFP) and trimethylsilyl (TMS) derivatives are given and discussed in relation to the chemical structures. Mass spectra of homologous derivatives were shown to be very similar but some fragments were specific for the chain length of the alkyl moiety and can be used for identification and a quantitative estimation of glucuronides in urine samples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001940050106
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  • 38
    Electronic Resource
    Electronic Resource
    Electrophysiological and ultrastructural correlates of cryoinjury in sciatic nerve of the freeze-tolerant wood frog, Rana sylvatica (1999)
    Springer
    Journal of comparative physiology 169 (1999), S. 351-359 
    Details
    ISSN: 1432-136X
    Keywords: Key words Freeze tolerance ; Sciatic nerve ; Cryoinjury ; Dehydration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We investigated function and ultrastructure of sciatic nerves isolated from wood frogs (Rana sylvatica) endemic to the Northwest Territories, Canada, following freezing at −2.5 °C, −5.0 °C, or −7.5 °C. All frogs frozen at −2.5 °C, and most frogs (71%) frozen at −5.0 °C, recovered within 14 h after thawing began; however, frogs did not survive exposure to −7.5 °C. Sciatic nerves isolated from frogs frozen at −7.5 °C were refractory to electrical stimulation, whereas those obtained from frogs surviving exposure to −2.5 °C or −5.0 °C generally exhibited normal characteristics of compound action potentials. Frogs responded to freezing by mobilizing hepatic glycogen reserves to synthesize the cryoprotectant glucose, which increased 20-fold in the liver and 40-fold in the blood. Ultrastructural analyses of nerves harvested from frogs in each treatment group revealed that freezing at −2.5 °C or −5.0 °C had little or no effect on tissue and cellular organization, but that (lethal) exposure to −7.5 °C resulted in marked shrinkage of the axon, degeneration of mitochondria within the axoplasm, and extensive delamination of myelin sheaths of the surrounding Schwann cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003600050231
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  • 39
    Electronic Resource
    Electronic Resource
    Echinococcus granulosus: praziquantel treatment against the metacestode stage (1999)
    Springer
    Parasitology research 85 (1999), S. 999-1006 
    Details
    ISSN: 1432-1955
    Keywords: Key wordsEchinococcus granulosus ; Praziquantel ; Metacestode ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The efficacy of praziquantel against the metacestode of Echinococcus granulosus was studied by means of in vitro incubations or in vivo experiments. The results of in vitro incubations indicated that the effectiveness of praziquantel was higher when the parasite material comprised cysts from cyst masses than in the case of intact cysts that retained their adventitial layer. Ultrastructural alterations in the germinal layer of collapsed cysts incubated in vitro were detected. The results obtained in mice after 4 months of treatment demonstrated no significant difference between the control and treated groups with regard to the number and wet weight of developed cysts. However, ultrastructural alterations were detected in the cyst tissue that were similar to those described in the in vitro experiment. In contrast, the effect of chemoprophylaxis on the number and the wet weight of developed cysts was extremely significant as compared with the control value, the efficacy being 99.41% and 98.32%, respectively. Moreover, ultrastructural observations of the cyst tissue revealed loss of its integrity, and no intact cyton was observed in the germinal layer of the developed cyst.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004360050672
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  • 40
    Electronic Resource
    Electronic Resource
    Morphology and ultrastructure of the anterior adhesive areas of the capsalid monogenean parasites Benedenia rohdei from the gills and B. lutjani from the pelvic fins of Lutjanus carponotatus (Pisces: Lutjanidae) (1999)
    Springer
    Parasitology research 85 (1999), S. 399-408 
    Details
    ISSN: 1432-1955
    Keywords: Key words Monogenea ; Capsalidae ; Benedenia rohdei ; B. lutjani ; Ectoparasites ; Lutjanus carponotatus ; Glands ; Ultrastructure ; Adhesion ; Attachment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The anterior adhesive areas of Benedenia rohdei from the gills and B. lutjani from the pelvic fins of Lutjanuscarponotatus at Heron Island, Australia, were studied using scanning and transmission electron microscopy. All specimens were fixed when detached from host tissue. Both monogenean species have two disc-like anteroventral attachment organs, each of which has an anterolateral adhesive area divided into three adjacent zones by tegument from the ventral surface of the attachment organ. A rod-shaped secretion and a smaller, roughly spherical secretion are associated with the anterior adhesive areas in both species; a third type of secretion occurs anteriorly but outside these adhesive areas. The electron-dense spherical secretory bodies released onto the anterior adhesive zones in these Benedenia spp. are of a single type and differ ultrastructurally from those previously reported in monogeneans living on teleost hosts. A correlation, therefore, between secretion morphology and host type is not supported. No relationship was found between parasite microhabitat and secretion morphology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004360050566
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  • 41
    Electronic Resource
    Electronic Resource
    Monitoring of nicotine in air using sorptive enrichment on polydimethylsiloxane and TD-CGC-NPD (1999)
    Springer
    Chromatographia 49 (1999), S. 520-524 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Sorptive preconcentration ; Air monitoring ; Nicotine ; Hospital air
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A novel method for the enrichment of nicotine from gaseous samples is presented. It is based on the sampling of 6 liters of air onto a cartridge packed with 100% polydimethylsiloxane (PDMS) particles. The analytes are dissolved (partitioned) into the PDMS phase which results in much better recoveries and reproducibilities compared to those obtained on common adsorbents. The PDMS tube is then placed in a thermal desorption (TD) unit connected to a CGC-NPD or CGC-MS system. The procedure was employed for routinely monitoring air in a hospital. Nicotine was typically found at levels ranging from 5 to 250 μg m−3 (ppb) depending on the location and number of smokers present. Additionally, the efficiency of nicotine filters was determined by sampling simultaneously at the filter in- and outlet and was found to be 46%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467752
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  • 42
    Electronic Resource
    Electronic Resource
    [60] Fulleropyrrolidine functionalized polysiloxane as a stationary phase for capillary gas chromatography (1999)
    Springer
    Chromatographia 49 (1999), S. 293-298 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; [60] Fulleropyrrolidine polysiloxane ; High temperature stationary phase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary In this paper, a new type of [60]fulleropyrrolidine functionalized polysiloxane in which the fullerene moieties were incorporated in the main polysiloxane chain was synthesized the first time and used as a stationary phase for capillary gas chromatography. It demonstrated high column efficiency (2600–2866 plates m−1, on a 250 μm diameter column, for naphthalenek=3.1–3.2, 120 °C), a wide operational temperature range (90–360 °C) and outstanding thermostability. It can be used at 360 °C with a baseline drift of 5∼8×10−15A. Benzene homologues, aromatic hydrocarbons, polar compounds such as alcohols, esters, ketones, anilines and phthalic diesters can be seperated well on this column.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467559
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  • 43
    Electronic Resource
    Electronic Resource
    Peak capacity in packed capillary column solvating gas chromatography (1999)
    Springer
    Chromatographia 49 (1999), S. 333-337 
    Details
    ISSN: 1612-1112
    Keywords: Supercritical fluid chromatography ; Gas chromatography ; Solvating gas chromatography ; Peak capacity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary In this paper, a general peak capacity expression was evaluated using columns containing various packing materials under solvating gas chromatography (SGC) conditions. Differing from column efficiency, peak capacity can describe both separation capability and speed when introducing the dead time into the peak capacity expression. Various factors that influence peak capacity in SGC are described, including particle pore size, chemical surface modification, particle size, column length, temperature, and pressure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467566
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  • 44
    Electronic Resource
    Electronic Resource
    Microwave assisted extraction and sonication of polychlorobiphenils from river sediments and risk assesment by toxic equivalency factors (1999)
    Springer
    Chromatographia 49 (1999), S. 21-27 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Microwave and ultrasonic extraction ; River sediment ; Dioxin-like polychlorobiphenyls ; Toxic equivalency factors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Microwave extraction and ultrasonication of dioxin-like polychlorobiphenyls (PCBs) from sediment samples were investigated. After separation of dioxin-like PCBs from a sample matrix on an acidic-alkaline silica gel column, dioxin-like PCBs were determined by GC-ECD, using dual capillary columns. Recoveries of dioxin-like PCBs in river sediment samples exceeded 80% by both extraction techniques. Toxic equivalency factors and their use for the PCB congeners investigated were applied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467182
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  • 45
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    Electronic Resource
    Conversions of carbon monoxide oxidation over Pt−Rh alloy catalysts calculated by a new gas chromatographic technique (1999)
    Springer
    Chromatographia 49 (1999), S. 285-292 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Reversed-flow gas chromatography ; Carbon monoxide oxidation ; Bimetallic Pt−Rh catalysts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Catalytic fractional conversions of carbon monoxide to carbon dioxide over Pt−Rh alloy catalysts in the presence of excess oxygen, under steady-state or non steady-state conditions, as well as corresponding rate constants for the CO oxidation reaction were measured by using the reversed-flow gas chromatographic technique. From the variation of the conversions with temperature, maximum values of conversions were found, which depend on the catalysts nature (Pt content), while from the variation of the rate constants with temperature, activation energies for the CO oxidation reaction were determined, which also depend on the catalyst Pt content. The results suggest a synergism between Pt and Rh in the Pt−Rh bimetallic catalysts in accordance with previous works, showing that reversed-flow gas chromatography can be used with simplicity and accuracy for the kinetic study of the CO oxidation reaction, which is of technological importance for the control of air pollution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467558
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  • 46
    Electronic Resource
    Electronic Resource
    A very thick film open-tubular trap for headspace capillary gas chromatography (1999)
    Springer
    Chromatographia 49 (1999), S. 321-326 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Headspace analysis ; Open-tubular trap ; Very thick film column
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An open-tubular trap with a very thick film was studied for “full on-line” headspace capillary gas chromatography, and was used as an enrichment trap for headspace sampling. The preparation of the open-tubular column with up to an 80 μm thick film, by combining both static and dynamic coating, is described in detail. The break-through volume for the open-tubular trap of different film thickness, as the loading capacity for HS sampling, does not increase linearly in proportion to the film thickness. A study of the difference between a packed adsorbent trap and an open-tubular trap shows that HS capillary GC with open-tubular trap loses less of the retention capacity, has better resolution ability and higher recovery. By independently and rapidly heating the open-tubular trap, the GC peaks may have higher resolution. Examples of successful analyses, by the opentubular trap with “full on-line” HS capillary GC, include trace aromatic hydrocarbon (1 ppm-100 ppm) in polybutadiene-styrene rubber and trace alcohol and acrylic esters (10 ppm–1000 ppm) in polyacrylate hydrous emulsion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467564
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  • 47
    Electronic Resource
    Electronic Resource
    Retention system, thermodynamic properties and structure correlations of environmental analytes (1999)
    Springer
    Chromatographia 49 (1999), S. 385-390 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Structure correlations ; Polycyclic aromatic hydrocarbons ; Polychlorinated biphenyls ; Polychlorinated pesticides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A composite chromatographic retention index system has been developed for identifying polycyclic aromatic hydrocarbons, polychlorinated biphenyls and polychlorinated pesticides. When retention indices and thermodynamic data of polycyclic aromatic hydrocarbons on 5% phenylmethylsiloxane stationary phase were compared with those obtained on polydimethylsiloxane a correlation was found between retention and electronic properties. Determination and quantitation of individual contaminants in water and sediment samples from Lake Mecoacán were achieved by capillary gas chromatography with flame ionization and electrocapture detection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467611
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  • 48
    Electronic Resource
    Electronic Resource
    Characterisation of paint layers in Chinese archaelogical relics by pyrolysis-GC-MS (1999)
    Springer
    Chromatographia 49 (1999), S. 268-272 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Mass spectrometry ; Analytical pyrolysis ; Chinese art objects ; Mercury analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A few samples of polychrome Chinese archaeological objects of art have undergone analytical pyrolysis coupled with GC-MS to evaluated the possibility of contemporary characterization of the pigments as well as the organic media used. The red pigment cinnabar (HgS) is easily media used. The red pigment cinnabar (HgS) is easily detected, whereas in the case of organic components positive results are only found where the matrices are resistant to archaeological environmental conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467555
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  • 49
    Electronic Resource
    Electronic Resource
    Polybutadiene-coated zirconia packing materials in solvating gas chromatography using carbon dioxide as mobile phase (1999)
    Springer
    Chromatographia 49 (1999), S. 431-435 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Supercritical fluid chromatography ; Solvating gas chromatography ; Polybutadiene coated zirconia ; CO2 mobile phase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary In this paper, practical considerations of column efficiency, separation speed, thermal stability, and column polarity of capillary columns packed with polybutadiene-coated zirconia were investigated under solvating gas chromatography (SGC) conditions using carbon dioxide as mobile phase. When compared with results obtained from conventional porous octadecyl obtained from conventional porous octadecyl bonded silica (ODS) particles, PBD-zirconia particles produced greater change in mobile phase linear velocity with pressure than conventional ODS particles under the same conditions. The maximum plate number per second (Nt) obtained with a 30 cm PBD-zirconia column was approximately 1.5 times higher than that obtained with an ODS column at 100 °C. Therefore, the PBD-zirconia phase is more suitable for fast separations than conventional ODS particles in SGC. Maximum plate numbers per meter of 76,900 and 63,300 were obtained using a 57 cm×250 μm i.d. fused silica capillary column packed with 3 μm PBD-zirconia at 50 °C and 100 °C, respectively. The PBD-zirconia phase was stable at temperatures up to 320 °C under SGC conditions using carbon dioxide as mobile phase. Polarizable aromatic compounds and low molecular weight ketones and aldehydes were eluted with symmetrical peaks from a 10 cm column packed with 3 μm PBD-zirconia. Zirconia phases with greater inertness are required for the analysis of more polar compounds by SGC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467619
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  • 50
    Electronic Resource
    Electronic Resource
    Estimation of retention times of homologous series in temperature programmed gas chromatography (1999)
    Springer
    Chromatographia 49 (1999), S. 509-512 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Homologous series ; Retention times
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary It is shown how to estimate the retention times of homologous series members in linear temperature programmed gas chromatography with the aid of a spread-sheet. Both the ease of estimation and the accuracy of the estimation depend on whether the homologue is eluted during the rising portion of the temperature program or the hold time at the end, and also on whether the homologous series is eluted from one injection or a number of injections. When all members of the series elute in the one chromatographic run the percentage standard deviation of the predicted retention times from the experimental retention times is 0.1. When members of the series elute in different chromatographic runs, the percentage standard deviation of predicted times from experimental times is 0.6, compared with an experimental percentage standard deviation for replicates of 0.5.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467750
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  • 51
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    Electronic Resource
    Efficiency of direct solid-phase microextraction from water-comparison of different fibre types including a new C8-coating (1999)
    Springer
    Chromatographia 49 (1999), S. 686-690 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Solid-phase microextraction ; Fibre coating ; Volatile organic compounds ; Semi-volatile organic compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The efficiency of direct solid-phase microextraction (SPME) was determined for 27 selected volatile and semivolatile organic compounds (BTEX, chloro- and bromobenzenes, chlorinated pesticides and PCBs). The fibres used were 7μm polydimethylsiloxane (PDMS), 30μm PDMS, 100μm PDMS, 65μm PDMS-divinylbenzene, 85μm polyacrylate, 65μm Carbowax-divinylbenzene, 75μm Carboxen-PDMS and a new 65μm C8 fibre. Extraction yields for these compounds were calculated under standardised conditions: 75μm Carboxen-PDMS was found to be the most efficient fibre for compounds with low boiling points. Although 65μm C8 can be used for extraction of all compounds studied, in no one case is it the most effective coating. 100μm PDMS and the more polar coatings can be used for a broad range of compounds, whereas application of 7μm and 30μm PDMS cannot be recommended. Inter-fibre comparison revealed significant differences between three different Carboxen-PDMS fibres. The results enable suitable coatings to be chosen for each of the 27 compounds and for substances with similar properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02466913
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  • 52
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    The GC determination of cisplatin as platinum(II) from pharmaceutical preparations and blood sample of cancer patients (1999)
    Springer
    Chromatographia 49 (1999), S. 249-252 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Cisplatin determination ; Blood analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A capillary gas chromatographic method is described for the determination of cisplatin based on the complexation of platinum(II) with bis(isovalerylacetone) ethylenediimine (H2IVA2en) and extraction in chloroform. The chromatography was carried out on a BP1 or a BP5 column with an FID. Copper(II), nickel (II) and palladium(II) separated completely and did not affect the determination of platinum(II). The method was applied of the determination of cisplatin in a pharmaceutical preparation and blood samples of cancer patients after infusion of cisplatin. The amounts of cisplatin in blood were found to be within 246–283 ng mL−1 with a C.V. of 2.35–4.26%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467551
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  • 53
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    Electronic Resource
    Transition metal complex stationary phases for the CGC analysis of ethers, thioethers and ketones (1999)
    Springer
    Chromatographia 49 (1999), S. 273-280 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Complexation stationary phases ; Bonding metal complexes ; Capillary columns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The use of polysiloxanes with cyano or thiol groups as stationary phases for complexation gas chromatography is discussed. The polymers were obtained via polycondensation followed by polymerisation of the corresponding dichloro- or dimethoxy-silanes. Both the phases were modified by bonding transition metal chlorides with were modified by bonding transition metal chlorides with cyano (CuCl2 or CoCl2) and thiol groups (NiCl2 or CoCl2). The phases were examined in order to determine their application to the analysis of ethers, thioethers and ketones. Due to the presence of lone electron pairs on oxygen or sulphur atoms, the compounds should be capable of specific interacting with the electron-withdrawing centre of the liquid stationary phases. A number of retention parameters (retention indices, molecular retention indices and specific retention volume) were determined, which allowed characterisation of specific interactions between the bonded metal and the compound analysed. The results also enabled assessment of the influence of the structure of the compounds on their retention. The measurements were also carried out for the phases with free SH and CN groups as reference phases. The work demonstrates that the phases obtained may be useful for effective separations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467556
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  • 54
    Electronic Resource
    Electronic Resource
    Averaging the pressure and flow rate of the carrier gas in a gas chromatographic column (1999)
    Springer
    Chromatographia 49 (1999), S. 449-453 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Average column pressure ; Average column flow ; Specific retention volume ; Distribution coefficient
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A systematic derivation of corresponding equations shows that averaging the pressure and the flow rate of the mobile phase in a gas chromatographic column over the column length and over the time that an unretained component resides in the column, requires the use of three different compressibility correction factors,j 2 1 ,j 3 2 , andj 4 3 . When multiplied by the adjusted retention volume,V R-VM, the Martin and James mobile phase compressibility correction factorj 3 2 , only, produces the value of specific retention volume,V g T , which is connected unambiguously with the thermodynamic phase distribution coefficient,K, of the sorbate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467622
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  • 55
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    Electronic Resource
    Solid phase microextraction of volatiles from water using open cap vials (1999)
    Springer
    Chromatographia 49 (1999), S. 513-519 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Solid phase microextraction ; Open cap vials ; Volatile compounds (BTEX) ; Water matrix
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The testing of open cap vials in headspace solid-phase microextraction combined with capillary gas chromatography is reported. The losses of volatile analytes from such vials were analyzed theoretically and investigated experimentally. The benzene, toluene, ethylbenzene, and xylene isomers spiked in water were used as model compounds. Extraction yields and precision obtained under optimized experimental conditions as exposure time, desorption time and temperature were compared applying vials with open caps or sealed with teflon lined septa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467751
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  • 56
    Electronic Resource
    Electronic Resource
    Synergistic effect of mixed stationary phase in gas chromatography (1999)
    Springer
    Chromatographia 49 (1999), S. 567-571 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Mixed stationary phase ; Calixarenes ; Crown ethers ; Cyclodextrins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Mixed stationary phases containing of 25,27-dibutoxy-5,11,17,23-tetra-tert-butyl-26,28-diundecenyloxy calix [4]arene (C[4]B)+ω-undecylomethyl-18-crown-6 polysiloxane (PSO-11-18-C-6) and C[4]B polysiloxane (PSO-C[4]B)+permethyl-β-cyclodextrin (PM-β-CD) were investigated in capillary gas chromatography. By comparing their selectivity for positional isomers with that of the corresponding individual pure stationary phases, synergistic effects were found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467761
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  • 57
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    Gas chromatographic determination of 2-chloro-1-[[4-[(2,6-dichlorophenoxy)methyl]phenyl]methoxy]-4-methoxybenzene (SCH 48973), a potent anti-picornaviral agent, in dog serum (1999)
    Springer
    Chromatographia 49 (1999), S. 575-578 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Electron capture detector ; Anti-picornaviral agent in dog serum ; Enteroviruses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A gas chromatographic assay for the determination of SCH 48973, a potent broad spectrum anti-picornaviral agent, was developed and validated in dog serum. The method involved extraction with organic solvent followed by separation on a capillary column (DB-1) with quantitation by an electron-capture detector. The method was sensitive with a limit of quantitation of 10 ng mL−1. The linearity of the method was satisfactory as indicated by correlation coefficients of 〉0.999 and visual examination of the calibration curves. The method was precise with a coefficient of variation ranging from 2.3 to 13.2% and accurate with a bias ranging from −9.1 to 7.9%. Moreover, SCH 48973 was stable in dog serum after being subjected to three freeze-thaw cycles. The assay was shown to be sensitive, specific, accurate and precise, and reliable for use in pharmacokinetic or toxicokinetic studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467763
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  • 58
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    Analysis of organic pollutants in sewage by supercritical fluid extraction (1999)
    Springer
    Chromatographia 49 (1999), S. 399-405 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Solid phase adsorption ; Supercritical fluid extraction ; Sewage ; Organic pollutants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Analytical methods have been developed for the determination of organic pollutants of intermediate polarity in sewage. Water samples are first passed through a solid phase adsorption cartridge. The analytes are then extracted from the absorbent with supercritical CO2 into a small volume of trapping solvent. Finally, the extracts are analyzed directly by capillary gas chromatography and gas chromatography-mass spectrometer. The various parameters (pressure, temperature, type and concentration of modifiers, trapping solvent, flow rate and volume of supercritical fluid and equilibrium time) influencing the efficiency of extraction were studied. Extraction efficiencies for the test compounds are 〉70%, and relative standard deviations are 〈4.6% (n=3). The methods established were applied to the analysis of sewage at the Lanzhou Wastewater Treatment Plant, China. 66 organic pollutants were detected, of which 15 compounds appeared in the list of priority pollutants suggested by the US EPA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467613
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  • 59
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    Superior ECD Performance through Design and Application (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 24-28 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; ECD ; Micro-ECD ; GC detector ; organochlorine pesticides ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A new ECD, the HP 6890 Series Micro-ECD, was designed to address inherent deficiencies in classical electron capture detectors (ECD), especially with respect to sensitivity, linearity, dynamic range, and ruggedness. Several novel technologies were incorporated in the totally new design and were refined through practical testing and user feedback. Validation of the micro-ECD performance was accomplished through side-by-side testing of the Micro-ECD with previous ECDs following US EPA Contract Laboratory Program methods for pesticides and PCBs. In addition, extensive interviews were conducted with early users of the Micro-ECD who also had experience with other designs running a variety of ECD methods. The design and resulting performance improvements are described.
    Additional Material: 6 Ill.
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  • 60
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    Solid Phase Microextraction and GC-MIP-AED for the Speciation Analysis of Organomercury Compounds (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 181-182 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; microwave induced emission spectrometry ; speciation ; mercury ; SPME, headspace SPME ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 1 Ill.
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  • 61
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    Analysis of the Naturally Occurring Pesticide Rotenone by Capillary Gas Chromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 294-296 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; capillary ; fused silica ; rotenone ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No abstract
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 62
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    Rapid Method for the Determination of Thiabendazole and Imazalil Residues in Orange by Capillary Column Gas Chromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 303-304 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; food analysis ; pesticide residues ; thiabendazole ; imazalil ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 63
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    Pulsed Splitless Injection and the Extent of Matrix Effects in the Analysis of Pesticides (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 395-402 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; pulsed splitless injection ; pesticide residues ; matrix effects ; retention gap ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The applicability of pulsed splitless injection to the gas chromatographic analysis of pesticide residues in fruit and vegetables has been evaluated. 22 pesticides belonging to different chemical classes, including those known to be liable to matrix induced response enhancement, were selected for the study. The parameters of pressure pulse have been tested for optimum performance of injection. Application of the pressure pulse was found to decrease matrix effects during analyses of real samples. Further decline of matrix effects was obtained using higher sample injection volumes. The installation of a deactivated retention gap was necessary to obtain good peak shapes with injection volumes exceeding 1 μL of sample. Up to 4 μL was then injected without peak distortion and consequent loss of resolution. Using 4 μL pulsed splitless injection, matrix effects were almost completely eliminated even at very low concentration levels of analytes. The highest matrix effects observed for tested compounds at the lowest concentration level tested were in the range of 110-122%.
    Additional Material: 3 Ill.
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  • 64
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    Determination of Vapor Liquid Equilibrium from the Kovats Retention Index on Dimethylsilicone using the Wilson Mixing Model (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 565-588 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Kovats retention index ; vapor pressure ; boiling point ; Wilson activity coefficient ; binary phase diagrams ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Non-ideal mixing in a dimethylsilicone stationary phase is modeled according to the Wilson activity coefficient. Pure liquid vapor pressures of alkylated compound series are calculated from capillary GLC retention with the functional group heat of solution in a polymer solvent. The new method uses the Kovats index, molar mass, and functional group to determine the bubble line of a compound. Boiling points at reduced and normal pressure are compared to literature values of 194 gasoline components. An unlike molecular pair interaction parameter is derived, using only bubble line data of the pure liquids. Binary phase diagrams are constructed and compared to vapor liquid equilibrium data.
    Additional Material: 22 Ill.
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  • 65
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    Electronic Resource
    Intranuclear inclusions of meningioma associated with abnormal cytoskeletal protein expression (1999)
    Springer
    Brain tumor pathology 16 (1999), S. 86-91 
    Details
    ISSN: 1861-387X
    Keywords: Meningioma ; Intranuclear inclusion ; Immunohistochemistry ; Ultrastructure ; Intermediate filament
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We describe a case of meningothelial meningioma with a large number of intranuclear inclusions. Morphologically, these are divided into cytoplasmic inclusions and nuclear vacuoles. The cytoplasmic inclusion has a limiting membrane with cell organelles and filaments. Inclusions of this type are generally eosinophilic, like the cytoplasm. However, there are many inclusions that are more eosinophilic than the cytoplasm or that have a ground-glass appearance. Some of them may contain fine or coarse granules. On the other hand, the nuclear vacuole lacks a limiting membrane and appears empty. In most of the inclusions of this type, there is a faintly basophilic substance in the margin. Generally, the cytoplasmic inclusions are as immunopositive as cytoplasm with vimentin, but some of these cytoplasmic inclusions are more reactive. Under the electron microscope, abnormal aggregation of intermediate filaments is recognized in the cytoplasmic inclusions. It is considered that a strong reaction of cytoplasmic inclusions with vimentin immunostaining is due to abnormal aggregation of intermediate filaments. The present study distinctly demonstrates abnormal localization of intermediate filaments in the cytoplasmic inclusions, and it is suggested that the cytoskeleton participates in the evolution of the cytoplasmic inclusions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02478908
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  • 66
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    Masthead (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999) 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710301
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  • 67
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    Nanofiltrationsmembranen für Trennprobleme in organischen Lösungen (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 199-206 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Nanofiltration Membranes for Separation Problems in Organic Solutions.Nanofiltration based on rejection and flux features intermediate between those ultrafiltration and reverse osmosis is one of the technically and scientifically interesting membrane processes with a great future. Moreover, most commercial available nanofiltration membranes are only suitable for separation processes in aqueous solutions. A small number of composite membranes with a highly cross-linked selective layer show a technically interesting resistance towards organic solvents, such as ketones, esters, ethers or alcohols. The present article describes such nanofiltration membranes used for separation of low molecular weight chemical compounds from polar or nonpolar solvents, but also for the removal of organic compound from aqueous solutions. Methods of manufacturing and modifying such solvent stable composite membranes are shown, as are the conditioning of membranes and examples of industrial application.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710304
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  • 68
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    Seitliche Reaktandenzufuhr in großmaßstäblichen Wirbelschichtreaktoren - Modellierung am Beispiel der Sekundärlufteinblasung in WirbelschichtfeuerungenVorgetragen von T. KNÖBIG anläßlich der internen Arbeitssitzung des Fachausschusses „Energieverfahrenstechnik“, 20./22. April 1998 in Würzburg. (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 219-222 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710307
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  • 69
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    Numerische Simulation der Strömungsvorgänge und des Trennverhaltens von Suspensionen im freien Einzelspalt eines TellerseparatorsVortrag auf der GVC-Tagung „Mechanische Flüssigkeitsabtrennung“, 25. März 1998 in Freiburg. (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 249-253 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710315
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    CAPE in der Praxis  -  Möglichkeiten und Grenzen aus NutzersichtVortrag anläßlich der GVC-Jahrestagung, 24./26. Sept. 1997 in Dresden. (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 323-327 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: CAPE in Practice - Opportunities and Limits from the User's Point of View.CAPE tools comprise computer based tools and methods for the design of chemical processes - the use of which is indispensable in modern chemical engineering. This paper discusses the degree to which CAPE is already applied and whether limitations exist. Within BASF, the CAPE framework is provided by the “ProcessNet”, which integrates numerous simulation and design tools. The engineer relies alternatively on inhouse or commercial software. The advantage of CAPE in terms of efficiency depends not only on complex programs, but also to a large extent on the multiple use of intermediate data and program modules. The ProcessNet also features a hierarchical file structure to support the engineer's desktop management. The CAPE environment is being continuously improved. The main constraints on CAPE today are, for example, the missing link between fluid and solid applications, a deficit in data management and the poor state of development of advanced or special programs. The progress of research in this area is followed with great interest.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710403
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    Einfluß der Fluidisierungsbedingungen auf Abscheidung und Agglomeration von Aerosolen beim Durchgang durch Wirbelschichten (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 361-364 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710409
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    Modifizierung der Partikelwechselwirkung durch Beschichtung mit grenzflächenaktiven ReagenzienÜberarbeiteter Vortrag anläßlich der Sitzung des GVC-Fachausschusses „Grenzflächen“, 23. März 1998 in Freiburg. (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 372-376 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710412
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  • 73
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    Untersuchung zur Hydrodynamik und Kinetik an KATAPAK-Packungen (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 388-392 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710416
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  • 74
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    Konzentrationsprogrammierte Reaktionstechnik - Eine Methode zur Beurteilung des Anwendungspotentials instationärer Prozeßführungen bei PartialoxidationenTeil eines Vortrags anläßlich der 3. Merseburger Fachtagung „Automatisierung, Meßmethoden und Experimente in der chemischen Reaktionstechnik“, 6. Nov. 1997. (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 226-230 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710309
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  • 75
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    Zur Kopplung von Impuls- und Stofftransport an fluiden Phasengrenzen - Teil 1: TheorieVortrag (gekürzt) anläßlich der GVC-Jahres-tagung, 24./26. Sept. 1997 in Dresden. (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 472-477 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710510
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    VerGrößerung der spezifischen Oberfläche von Kristallen durch gezieltes Nutzen von PseudopolymorphenErweiterte Fassung eines Vortrags von ST. NORDHOFF (Vortragender) und J. ULRICH anläßlich der internen Arbeitssitzung des GVC-Fachauschusses „Kristallisation“, 2./6. März 1998 in Aachen. (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 487-490 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710514
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    Einfluß der Dimerisierung von Isobuten auf die MTBE-Produktion bei der reaktiven Destillation (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 500-503 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710518
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  • 78
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    Chemical Reaction and Reactor Design (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 518-518 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710523
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    Processing of Particulate Solids (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 520-520 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710526
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  • 80
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    GVC-Fachausschuß „Prozeß-und Anlagentechnik“ (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 516-517 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Die Sitzung des GVC-Fachausschusses „Prozeß- und Anlagentechnik“ fand am 25. und 26. Oktober 1998 in Kleve statt. Gemeinsam mit dem DECHEMA-Ausschuß „Computeranwendungen in der chemischen Industrie“ und dem GVC-Arbeitskreis „Produktionslogistik“ wurden aktuelle Problemstellungen aus der Industrie und neue Problemlösungsansätze aus der Forschung präsentiert und diskutiert.In seiner kurzen Begrüßung erläuterte der Ausschußvorsitzende H. SCHMIDT-TRAUB einerseits die Zielsetzung der Tagung und verdeutlichte andererseits den Teilnehmern die Ursachen und Konsequenzen des drastischen Rückgangs der Anfängerzahlen in den verfahrenstechnischen Studiengängen, was für Gesprächsstoff in den Pausen sorgte. Die anschließende Tagung umfaßte insgesamt 35 Vorträge in zehn Schwerpunktthemen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710522
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  • 81
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    Abwasser (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 523-524 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710532
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  • 82
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    Aktuelles (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 531-553 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710602
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  • 83
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    Abtrennen von Wertstoffen aus BauschuttVortrag anläßlich der GVC-Jahrestagung, 30. Sept./2. Okt. 1998 in Freiburg. (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 637-642 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710619
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  • 84
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    Wärmeintegration bei Batch-Prozessen (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 700-704 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710710
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  • 85
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    Rheologische Eigenschaften von wäßrigen nicht-ionischen Tensidlösungen in stationärer ScherströmungVortrag anläßlich der Sitzung des GVC-Fachausschusses „Rheologie“, 2./6. März 1998 in Aachen. (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 720-725 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710715
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  • 86
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    Systematische vergleichende Kostenanalyse von destillativen und extraktiven Stofftrennverfahren (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 669-673 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Systematic Comparative Cost Analysis of Separation Processes Based on Distillation and Extraction.Rectification is the most commonly used but not always the most economical method of thermal separation. Above all in the case of closely boiling mixtures it becomes very demanding with regard to both equipment and energy. It is often possible to replace rectification by another energetically more favourable separation process such as liquid-liquid distillation, decantation, or absorption. Owing to the resulting wealth of possibilities for the separation of a mixture it is desirable to gain further knowledge about the economics of individual processes and about the selection of suitable entrainers under given conditions.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710703
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  • 87
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    Die Hydrolyse von HCN als Zwischenschritt bei der Stickoxidbildung (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 613-618 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710614
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  • 88
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    Oxidische Schichten auf EisenChrom-Nickel-Werkstoffen und ihre chemischen Eigenschaften (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 609-612 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710613
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  • 89
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    Verfahren zum Abbau von organischen Schadstoffen durch indirekte Elektrooxidation (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 628-633 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710617
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  • 90
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    Kontinuierliche Dosierung und Dispergierung feindisperser, kohäsiver Feststoffe mit einem neuartigen Staubdosierer (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 685-688 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710706
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  • 91
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    Numerische Untersuchung der Strömungsverhältnisse im Innern von Hohlkegeldüsen mit Leitapparat (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 688-692 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710707
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  • 92
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    Kinetik der Umesterung von Ethanol und Butylacetat - Ein Modellsystem für die Reaktivrektifikation (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 704-708 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710711
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  • 93
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    BRICK - Ein 1-D-Simulationstool für Mehrphasenströmungen in Behältern (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 713-717 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710713
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  • 94
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    Vergleichende Untersuchungen zur nichtadiabaten Absorption im Film- und Blasen-KolbenregimeÜberarbeitete Fassung eines Postervortrages von U. HELBING anläßlich der GVC-Jahrestagung, 30. Sept./02. Okt. 1998 in Freiburg. (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 844-849 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710813
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  • 95
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    Möglichkeiten zur Vorausberechnung von Verweilzeitverteilungen (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 795-807 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Possible Approaches to the Prediction of Residence Time Distributions Although the experimental determination of residence time distributions is based on a black-box method, the signal shape also permits certain conclusions to be drawn about the internal conditions. However, if it is to provide a sole basis for elucidating process steps in a plant this method is soon overtaxed. A deeper theoretical penetration of the pertinent transport processes opens up the way ahead. However, since residence time distributions are based on mass-oriented considerations, substantial advances in fluid mechanics, where location-based considerations predominate, have not led to improved predictive capability. Yet the computer power now available offers a variety of ways of calculating residence-time distributions for a known flow profile, thus permitting a step in the direction of better predictability of residence time distributions. This article presents utilisable methods and evaluates them with regard to their demands on time and effort and their predictive power. Problems arising in connection with the models are discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710805
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  • 96
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    Dreiphasenrektifikation in Packungskolonnen (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 819-823 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710807
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  • 97
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    Einfluß von Polyelektrolytkomplexschichten auf Trennleistung und Foulingverhalten oberflächen- und bulkmodifizierter MembranenPosterbeitrag anläßlich des 7. Aachener Membran Kolloquiums, 9./11. März 1999 in Aachen. (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 839-844 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710812
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  • 98
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    In-situ-Bestimmung momentaner Reaktionsraten von Brennstoffpartikeln durch simultane Messung von Partikeltemperatur und GrößeÜberarbeitete und ergänzte Version des Vortrages von T. REICHELT anläßlich der GVC-Jahrestagung, 30. Sept./2. Okt. 1998 in Freiburg. (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 857-861 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710816
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  • 99
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    Parallelisierte Synthese und schnelle katalytische Testung von Katalysatorbibliotheken für Oxidationsreaktionen (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 873-877 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710820
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    GVC-Fachausschuß „Gasreinigung“Berichterstatter: Dipl.-Ing. ACHIM DITTLER, Institut für Mechanische Verfahrenstechnik und Mechanik, Universität Karlsruhe (TH), D-76128 Karlsruhe, und Priv.-Doz. Dr.-Ing. EBERHARD SCHMIDT, DEGUSSA-HÜLS AG, D-63403 Hanau (1999)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 882-883 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Die diesjährige interne Sitzung des GVC-Fachausschusses „Gasreinigung“ wurde zusammen mit der Arbeitssitzung des Fachausschusses „Energieverfahrenstechnik“ am 19. und 20. April im Tagungszentrum „Festung Marienburg“ in Würzburg abgehalten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330710822
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