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  • 1
    Electronic Resource
    Electronic Resource
    Cytostatic quinones. 3. Synthesis of benzotriazolequinones by a new oxidation with m-chloroperbenzoic acid. Biochemical studies (1978)
    s.l. : American Chemical Society
    Journal of medicinal chemistry 21 (1978), S. 578-582 
    Details
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jm00204a014
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  • 2
    Electronic Resource
    Electronic Resource
    Preparation of MoS2 and WS2 catalysts by in situ decomposition of ammonium thiosalts (1998)
    Springer
    Catalysis letters 52 (1998), S. 55-61 
    Details
    ISSN: 1572-879X
    Keywords: MoS2 ; WS2 ; thiosalts ; in situ activation ; hydrodesulfurization ; mechanochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The in situ decomposition of ammonium thiometallates during the hydrodesulfurization (HDS) of dibenzothiophene (DBT), to obtain molybdenum disulfide and tungsten disulfide catalysts, was investigated. It was found that very efficient catalysts for the HDS of DBT were obtained by in situ decomposition. Mechanical uniaxial pressing of the precursors (ammonium thiometallates) affected both textural and catalytic properties of the catalysts. Surface areas of molybdenum and tungsten disulfides increased as a function of uniaxial pressing, while catalytic activities went through a maximum. For MoS2, the hydrogenation selectivity was much higher for in situ catalysts than for ex situ ones. For WS2 catalysts, the hydrogenation selectivity was less sensitive to the condition of decomposition (ex situ/in situ). The surface S/M (M = Mo, W) atomic ratio from the Auger signal decreased as a function of uniaxial pressing, while the C/M ratio remained almost constant at 1.6. The best catalyst showed an experimental S/Mo ratio that is slightly higher than the stoichiometric value. The effect of in situ decomposition and mechanical deformation of thiometallate precursors is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019067319305
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  • 3
    Electronic Resource
    Electronic Resource
    Halomethyl-1,2,3-triazole derivatives: A new type of alkylating agent active in mouse transplantable tumors (1978)
    Springer
    Cancer chemotherapy and pharmacology 1 (1978), S. 243-247 
    Details
    ISSN: 1432-0843
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A number of halomethyl-1,2,3-triazole derivatives have been tested for their effect on ICR Swiss female mice bearing the Ehrlich carcinoma ascites (ECA) tumor. Two of these compounds, namely 4-bromomethyl-1-(2,3,4,6-tetra-0-acetyl-β-D-glucopyranosyl)-1,2,3-triazole and 4-iodomethyl-1-(2,3,4,6-tetra-0-acetyl-β-D-glucopyranosyl)-1,2,3-triazole, referred to here as compounds H and K, respectively, promoted a significant increase in the median survival time (145% and 195%) when injected IP for 9 consecutive days at doses of 75 mg/kg/injection and 100 mg/kg/injection, respectively. DNA synthesis, as measured by (methyl-3H)thymidine incorporation into trichloroacetic acid-precipitated material, was always inhibited by all the triazole derivatives to a greater extent than the incorporation of (5,6-3H)uridine, (5-3H)proline, and (6-3H)-glucose. Moreover, inhibition of DNA synthesis was complete and irreversible following exposure to selected triazole derivatives. Compounds H and K inhibited the incorporation of di(3H)methyl sulfate by ECA cells. In addition, compound K promoted the release of radioactivity associated with trichloroacetic acid-insoluble material coming from (8-3H)guanosine-prelabeled cells. This release of radioactivity did not occur when cells were prelabeled with (methyl-3H)thymidine. It is concluded from these results that these triazole derivatives act as alkylating agents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00257157
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  • 4
    Electronic Resource
    Electronic Resource
    Distances between populations ofDrosophila subobscura, based on chromosome arrangement frequencies (1975)
    Springer
    Theoretical and applied genetics 45 (1975), S. 231-241 
    Details
    ISSN: 1432-2242
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Distances between populations ofDrosophila subobscura, based on differences in the frequencies of chromosomal arrangements have been estimated using data from about 65 populations. The distances have been calculated using the formula: $$D = \frac{1}{{2r}}{\text{ }}\sum\limits_{j = 1}^r {\sum\limits_{k = 1}^{Sj} {|p_{1jk} - } p_{2jk} |} {\text{ }},$$ wherer is the number of loci or chromosomes (in the case of chromosomal polymorphism) considered,p 1jk the frequency of the allele or chromosomal arrangementk in the locus or chromosomej in the first population, andp zjk the corrsponding value in the second population. The main conclusion drawn from this analysis is that historical as well as adaptive factors are important in explaining the geographical distribution of chromosomal arrangements inD. subobscura. In general, isolated populations maintain primitive features in their chromosomal polymorphism. This is reflected in a tendency to similarity between these populations. Also, a very sharp effect of geographical barriers is detected in the distribution of the chromosomal arrangements. Two main factors are considered responsible for the strong effect that isolation has on geographical distribution of chromosome arrangements. These factors are the non-recurrence of rearrangements and the difficulty of establishing in one population the supergenes originated in another area, because of lack of coadaptation with the gene pool of the recipient population.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00831894
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  • 5
    Electronic Resource
    Electronic Resource
    The smooth endoplasmic reticulum in neurohypophysial axons of the rat: Possible involvement in transport, storage and release of neurosecretory material (1979)
    Springer
    Cell & tissue research 199 (1979), S. 415-429 
    Details
    ISSN: 1432-0878
    Keywords: Hypothalamo-neurohypophysial system (rat) ; Axoplasmic transport ; Smooth endoplasmic reticulum ; Neurosecretory granules ; Microvesicles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The intra-axonal organization of the smooth endoplasmic reticulum was studied in the neurohypophysis of rats during and after water deprivation. Parallel to conventional electron microscopy, the material was treated with a double impregnation staining technique specifically designed to contrast the intracellular membranous system. In conventionally stained ultrathin sections from severely dehydrated rats most axons appeared to be free of membranous organelles, whereas corresponding axons treated with the double-impregnation technique generally exhibited a highly developed system of smooth endoplasmic reticulum. In axonal endings, both techniques revealed a profusion of microvesicles in intimate relationship with tubular elements of the smooth endoplasmic reticulum. In short-term (12 h) rehydrated rats, a similarly developed system of smooth endoplasmic reticulum was still observed at all axonal levels with both procedures. After 24 to 48 h of rehydration the tubules of the smooth endoplasmic reticulum exhibited, in double impregnated material, numerous dilatations which resembled the adjacent neurosecretory granules. In conventionally stained ultrathin sections, an accumulation of electron dense material occurred within tubules of the smooth endoplasmic reticulum in the more proximal axonal segments, while in the more terminal segments, which contained numerous elongated granules, membrane continuity was frequently observed between newly formed granules and the smooth endoplasmic reticulum. After 7 days of rehydration the general pattern of the axonal smooth endoplasmic reticulum was comparable to that in untreated rats. These results are discussed in the light of a suggested involvement of the axonal smooth endoplasmic reticulum in the non-granular transport of neurosecretory material in connection with (1) storage in distally formed granules, and (2) release via microvesicles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236080
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  • 6
    Electronic Resource
    Electronic Resource
    Differences in the immunoreactivity to phenylethanolamine-N-methyltransferase in the central adrenergic neurons of four strains of rats (1991)
    Springer
    Cell & tissue research 265 (1991), S. 307-315 
    Details
    ISSN: 1432-0878
    Keywords: Brain, vertebrate ; Phenylethanolamine-N-methyltransferase ; Adrenaline ; Immunocytochemistry ; HPLC ; Rat (Wistar, Sprague-Dawley, Long Evans, Zucker)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immunocytochemistry was used to compare the immunoreactivity of adrenergic neurons to a well characterized specific immunoserum to phenylethanolamine-N-methyltransferase (PNMT) in different strains of rats commonly used in research studies. In adult animals, marked differences were found in the PNMT-immunoreactivity of neurons between Wistar rats and other strains, resulting in a lower PNMT-immunostaining intensity (i) within neuronal perikarya of the medulla oblongata, and (ii) more strikingly, within nerve fibers and terminals located in various brain regions. This low PNMT-immunoreactivity of nerve fibers was detected both in 14- and 35-day-old Wistar rats. On the other hand, the HPLC measurement of catecholamines, in particular of adrenaline in the hypothalamus and the medulla oblongata, did not show any difference between adult Wistar and Sprague-Dawley rats. These data suggest that the low PNMT-immunoreactivity observed in central adrenergic neurons of the Wistar rats is related to the poor recognition of the antigen by the PNMT-antibody used. Possibly, these nerve cells mainly display an isoform of the enzyme that is immunologically different from the PNMT contained within the adrenergic neurons of other rat strains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00398078
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  • 7
    Electronic Resource
    Electronic Resource
    Adrenergic innervation of the dorsal vagal motor nucleus: possible involvement in inhibitory control of gastric acid and pancreatic insulin secretion (1990)
    Springer
    Cell & tissue research 259 (1990), S. 535-542 
    Details
    ISSN: 1432-0878
    Keywords: Adrenaline ; Medulla oblongata ; Parasympathetic nervous system ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Morphological and physiological approaches were used to investigate the possible role of an adrenergic innervation of the dorsal vagal complex in the control of basal gastric acid and pancreatic insulin secretion in the rat. The use of retrograde-tracing methods with injections of True Blue or of wheat-germ agglutinin into the stomach or pancreas first confirmed that most vagal preganglionic neurons innervating these two viscera are localized in the dorsal motor nucleus of the vagus, a number of them connected to both viscera. Light- and electron-microscopic investigation of the organization of adrenergic neuronal structures immunoreactive to phenylethanolamine-N-methyltransferase within this medullary nucleus further revealed: (i) that adrenergic axons establish profuse synaptic connections of the symmetrical type with perikarya and dendrites of this nucleus, and (ii) that several of these adrenergic fibers are connected with retrogradely labeled neurons innervating the stomach and/or pancreas. Lastly, measurements of basal gastric acid output and plasma insulin clearly indicated that both visceral secretions are rapidly and conspicuously decreased by local infusion of 2 nM adrenaline within the dorsal vagal complex. Taken together, these data strongly suggest that the adrenergic innervation of the dorsal medulla oblongata is involved in direct synaptic inhibition of the parasympathetic preganglionic neurons of the vagus that control secretion of gastric acid and pancreatic insulin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01740781
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  • 8
    Electronic Resource
    Electronic Resource
    Immunolocalization of Bcl-xL/S in the central nervous system of neonatal and adult rats (1997)
    Springer
    Cell & tissue research 288 (1997), S. 59-68 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Apoptosis ; Neuronal plasticity ; Hypothalamus ; Astrocytes ; Immunocytochemistry ; Western blot ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. A polyclonal antibody raised against a peptide corresponding to the (2–19) amino-terminal sequence of the Bcl-xL/S protein was used to localize Bcl-x immunostaining in the central nervous system of rats at various postnatal ages. Whereas Bcl-x immunostaining was present in virtually all neurons of young animals (4 days postnatal), this staining became progressively restricted during the course of postnatal development. In adults, Bcl-x immunostaining was particularly strong in certain neurons present in a few hypothalamic nuclei, such as the supraoptic or the arcuate nuclei. Moderate staining was observed in some discrete brain regions, such as the olfactory bulb, the hippocampus, some catecholaminergic nuclei of the brainstem, and the cerebellum. Strong Bcl-x immunostaining was also exhibited in axon-like fibers located in the pyriform cortex, the median eminence, the dorsal medulla oblongata, and spinal cord. Bcl-x immunostaining was also present in astrocytes scattered throughout the white matter in the brain and the spinal cord, but was absent from those located in gray matter. Staining was particularly strongly expressed in reactive astrocytes densely packed along the borders of a central lesion or surrounding them, and in a large number of reactive astrocytes detected at a distance from the lesion. Our data suggest that, in addition to the possible stimulating effects on cell survival generally ascribed to Bcl-x, its maintained expression throughout adulthood or its re-expression following injury characterizes those neuronal or non-neuronal cells of the adult central nervous system that synthesize a range of molecules enabling them to adapt rapidly and successfully to a changing environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050792
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  • 9
    Electronic Resource
    Electronic Resource
    Exotica/FMDC: A workflow management system for mobile and disconnected clients (1996)
    Springer
    Distributed and parallel databases 4 (1996), S. 229-247 
    Details
    ISSN: 1573-7578
    Keywords: Workflow ; Disconnected Operation ; Mobile Computing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Workflow Management Systems (WFMSs) automate the execution of business processes in environments encompassing large numbers of users distributed over a wide geographic area and using heterogeneous resources. Current implementations allow the definition and controlled execution of complex and long lived business processes as the basis for an enterprise-wide collaborative system but, in most cases, the autonomy of the users is greatly restricted due to architectural and design considerations. In particular, existing systems are built around a centralized server. As a result, users need to maintain an uninterrupted connection with the server to perform the different tasks assigned to them. This is a severe restriction, especially when considering the emergence of mobile computing, and the increase in use of laptops and small computers which are connected to the network only occasionally and which will, undoubtedly, be the tool of choice for many users. This paper addresses the problem of supporting disconnected workflow clients in large workflow management systems while still preserving the correctness of the overall execution and allowing coordinated interactions between the different users regardless of their location.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00140951
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  • 10
    Electronic Resource
    Electronic Resource
    Electron microscopic study of the orthograde axonal transport of horseradish peroxidase in the supraoptico-neurohypophysial tract of the rat (1978)
    Springer
    Cell & tissue research 194 (1978), S. 525-531 
    Details
    ISSN: 1432-0878
    Keywords: Hypothalamo-neurohypophysial tract ; Orthograde transport ; Horseradish peroxidase ; Smooth endoplasmic reticulum ; Neurosecretory granules ; Microvesicles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Horseradish peroxidase (HRP) has been used as a protein tracer in order to visualize the ultrastructural sites of the orthograde transport of protein macromolecules in the hypothalamo-neurohypophysial tract of the rat. After a local injection of HRP within the supraoptic nucleus, the reaction product was observed: (1) mainly in tubules of the smooth endoplasmic reticulum in the more proximal part of the axons, and (2) in granules and microvesicles of the axon terminals. Observations on thick sections clearly showed the existence of a relationship between the smooth endoplasmic reticulum containing HRP and the labeled granules or microvesicles. These data are in good agreement with previous findings showing the existence of direct continuity between tubules of the smooth endoplasmic reticulum and a fraction of the neurosecretory granules and microvesicles. This evidence further reinforces the hypothesis that the latter organelles may possibly originate locally in the axons from the tubules of the smooth endoplasmic reticulum which may therefore be proposed as a possible vehicle for a non-granular intra-axonal transport of neurosecretory material in neurosecretory neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236171
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