Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Chronic treatment with D1 and D2 dopamine receptor agonists: combined treatments interact to differentially affect brain levels of monoamines (1991)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 344 (1991), S. 281-285 
    Details
    ISSN: 1432-1912
    Keywords: Dopamine agonists ; D1 and D2 receptors ; Monoamines ; Parkinson's disease ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Recent evidence of functional interactions between D1 and D2 dopamine receptor subtypes has led to the concept that many of the behavioural effects of dopamine agonists occur only with activation of both receptor subtypes. Thus, combined treatment with dopamine agonists selective for each of the D1 and D2 receptors may be an effective therapy for Parkinson's disease, chiefly characterized by loss of central dopamine-containing neurons. In addition, recent hypotheses of the possible pathogenesis of this disorder have suggested that metabolism of dopamine by monoamine oxidase in the presynaptic terminal may contribute to the loss of dopaminergic cells, through the production of reactive by-products. Therefore, the effects of chronic (15 day) treatment of rats with different doses of (+)-4-propyl-9-hydroxynaphthoxazine (PHNO, a D2 receptor agonist), SKF 38393 (a D1 receptor partial agonist) or combinations of both drugs on levels of brain monoamines and some of their acidic metabolites were investigated. Little or no effects of the drugs were observed on measures of dopamine or noradrenaline when given separately, while each selective agonist dose-dependently reduced serotonin levels. Combined treatment with the two agonists produced profound effects on the catecholamines, but with no effect on 3,4-dihydroxyphenylacetic acid, the metabolite of dopamine produced by monoamine oxidase. In addition, the effects of combined treatment on serotonin levels were opposite of those of the drugs given independently. Concomitant treatment of animals with both D1 and D2 receptor agonists can therefore increase tissue levels of dopamine without increasing the potentially harmful metabolism of dopamine by monoamine oxidase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00183001
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Selective synthesis of 3-picoline via the vapor-phase methylation of pyridine with methanol over Ni1-x Co x Fe2O4 (x = 0, 0.2, 0.5, 0.8 and 1.0) type ferrites (2000)
    Springer
    Catalysis letters 65 (2000), S. 99-105 
    Details
    ISSN: 1572-879X
    Keywords: spinel structure ; ferrites ; pyridine methylation ; electron acceptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A series of Ni–Co ferrites with the general formula Ni1-x Co x Fe2O4 (x = 0, 0.2, 0.5, 0.8 and 1.0) was prepared by a low-temperature hydroxide coprecipitation route. The catalyst systems were characterized by adopting various physico-chemical techniques. Alkylation of pyridine with methanol was carried out in a down-flow vapor-phase reactor. The influence of surface acid–base properties, cation distribution in the spinel lattice and various reaction parameters are discussed. It was observed that the systems possessing x values ≥0.5 are selective for 3-picoline formation, whereas the ones with x values 0 and 0.2 give a mixture of 2- and 3-picolines. Pyridine conversion increased with the progressive substitution of Ni2+ ions by Co2+ ions. Cation distribution in the spinel lattice influences their acidic and basic properties, and these factors have been adequately considered as helpful to evaluate the activity of the systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019081608421
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Comparative performance of four multi-purpose trees associated with four grass species in the humid regions of Southern India (1992)
    Springer
    Agroforestry systems 17 (1992), S. 205-218 
    Details
    ISSN: 1572-9680
    Keywords: Pennisetum purpureum ; Panicum maximum ; Brachiaria ruziziensis ; Euchlaena mexicana ; Leucaena leucocephala ; Casuarina equisetifolia ; Acacia auriculiformis ; Ailanthus malabarica ; silvopastoral systems ; Southern India ; light interception ; biomass production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The results of a field trial conducted at the Livestock Research Station, Thiruvazhamkunnu, Kerala to study the compatibility of different components in a silvo-pastoral system revealed that growth and yield of fodder species were significantly influenced by the tree components only after tree canopy formation. The fodder species such as Pennisetum purpureum Schum., Panicum maximum Jacq., Brachiaria ruziziensis Griseb. and Euchlaena mexicana Schrad. grown in association with Casuarina equisetifolia J. R. & G. Forst. and Ailanthus malabarica DC recorded comparatively higher forage yield even after canopy formation. However, forage crops grown in combination with Acacia auriculiformis A. Cunn. ex Benth. and Leucaena leucocephala (Lam.) de Wit. registered relatively lower values for growth and yield. Increased light infiltration into the understorey due to the cladophyllous canopy can be attributed as reason for the higher fodder productivity under Casuarina. Due to the combination of crown size and shape, tree height and spacing the amount of light intercepted by Ailanthus also was very low. Among the four multi-purpose trees used, Acacia recorded the maximum growth rate followed by Casuarina, Ailanthus and Leucaena. Forage productivity of the four species was in the order: Pennisetum purpureum 〉 Panicum maximum 〉 Brachiaria ruziziensis 〉 Euchlaena mexicana. Casuarina with Pennisetum/ Panicm were found to be optimal tree — forage combinations for silvo-pastoral systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00054148
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Synthese, NMR-Spektroskopie und eine ab-initio/IGLO/GIAO-MP2-Studie der protonierten Fluorameisensäure und des Fluorcarbonyl-KationsOnium Ions, 49. Mitteilung. Diese Arbeit wurde von der National Science Foundation gefördert. A. B. dankt der Konrad-Adenauer-Stiftung für ein Stipendium. - 48. Mitteilung: G. K. S. Prakash, Q. Wang, G. Rasul, G. A. Olah, J. Organomet. Chem., im Druck. (1997)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 109 (1997), S. 1958-1961 
    Details
    ISSN: 0044-8249
    Keywords: Ab-initio-Rechnungen ; Carbokationen ; Fluor ; Fluorameisensäure ; NMR-Spektroskopie ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19971091723
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...