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
Filter
  • Adsorption kinetics  (7)
  • Endothelium  (3)
  • Engineering General  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Dissociation between endothelium-mediated increases in tissue cGMP levels and modulation of aortic contractile responses (1984)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 328 (1984), S. 221-223 
    Details
    ISSN: 1432-1912
    Keywords: Endothelium ; cGMP ; Smooth muscle contraction ; Rat aorta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Both methoxamine and clonidine elicited similar maximal contractions of rat isolated aorta in the absence of endothelium. These contractions were not associated with changes in tissue levels of cGMP or cAMP. In the presence of endothelium maximal methoxamine-induced contractions were not less than those elicited in the absence of endothelium but maximal clonidine-induced contractions were reduced to about 10% of those in the absence of endothelium. However, in the presence of endothelium both methoxamine and clonidine induced similar increases in tissue cGMP levels of about 1.5 to 2 fold; cAMP levels were unchanged. There is therefore a dissociation between endothelium-mediated inhibition of maximal contractile responses and increases in tissue levels of cGMP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00512078
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Effect of endothelium on basal and α-adrenoceptor stimulated calcium fluxes in rat aorta (1986)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 334 (1986), S. 63-70 
    Details
    ISSN: 1432-1912
    Keywords: Vascular smooth muscle ; Endothelium ; 45Ca flux ; Rat aorta ; α-Adrenoceptor agonists
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The rate of unstimulated influx of Ca2+ into rat aorta smooth muscle, measured as uptake of 45Ca, was inhibited in the presence of endothelium as compared to influx in the absence of endothelium. Efflux of 45Ca from unstimulated prelabelled tissues was also reduced in the presence of endothelium. In normal physiological solution the rate of influx and efflux of Ca2+ stimulated by B-HT 920 (1 and 10 μM), but not that stimulated by phenylephrine (30 nM and 1 μM), was also reduced in the presence of endothelium. In the presence of the calcium entry blocker flunarizine (3 μM), phenylephrine (1 μM) stimulated efflux of Ca2+ was inhibited by the presence of endothelium. A correlation between inhibition of Ca2+ influx and modulation of α-adrenoceptor agonist-induced contractions by endothelium could not be demonstrated, and methylene blue, an antagonist of endothelium mediated inhibition of B-HT 920 contractions, did not affect Ca2+ influx stimulated by the agonist. The effects of endothelium on Ca2+ influx and efflux are unlikely to be due to alterations by endothelium of diffusion of 45Ca or the agonists in the vessel. The results demonstrate that an endothelial derived factor or factors can reduce calcium influx into smooth muscle cells and also modulate the release of calcium from cells, perhaps by affecting intracellular calcium pumping mechanisms. A reduction of calcium influx cannot be the sole explanation for the modulatory effect of endothelium on α-adrenoceptor agonist-induced contractions but an effect on intracellular calcium metabolism may be important.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00498741
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Effect of endothelium and carbachol on α-adrenoceptor agonist stimulated uptake and efflux of 45Ca in rat isolated aorta (1987)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 336 (1987), S. 287-294 
    Details
    ISSN: 1432-1912
    Keywords: Endothelium ; Calcium fluxes ; Alpha ; Adrenoceptor agonist ; Rat aorta ; Carbachol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Preincubation with carbachol (10 μM) did not affect basal 45Ca accumulation by rat isolated aortic segments complete with endothelium, although 45Ca accumulation was enhanced by removal of endothelium. This confirms the observation that in the presence of endothelium Ca2+ influx in rat aorta is antagonized, and indicates that the basal release of an endothelial derived factor might be sufficient to maximally antagonize basal Ca2+ influx, or alternatively that EDRF released as a result of muscarinic stimulation does not have identical effects to the factor released under basal conditions. Accumulation of 45Ca stimulated by B-HT 920 but not that stimulated by phenylephrine was antagonized in the presence of endothelium. Contractions elicited by B-HT 920 were abolished in the presence of endothelium while contractions evoked by phenylephrine were reduced by about 50%. Preincubation with 10 μM carbachol antagonized both phenylephrine (1 μM) stimulated 45Ca accumulation and contractile responses in the presence of endothelium to about the same extent. Therefore, it might be concluded that the inhibitory effect of EDRF in this tissue is due to an inhibition of stimulated Ca2+ influx. However, while addition of carbachol to tissues precontracted with phenylephrine elicited an immediate relaxation in the presence of endothelium, this relaxation could not be correlated with a reduction in tissue accumulation of 45Ca. Carbachol also antagonized the phenylephrine-induced reduction of tissue 45Ca content (i.e. efflux of Ca2+), in tissues preloaded with 45Ca. This implies that the initial endothelial-mediated relaxant effect of carbachol in precontracted tissues cannot be explained either by reduced influx or by an enhanced efflux of Ca2+ from the smooth muscle cells. Therefore, it is concluded that although EDRF mediates a reduction in agonist-induced Cat2+ uptake it also exerts other effects, one of which may be an initial redistribution of intracelllar Ca2+, resulting in a reduction in free intracellular Ca2+ levels and therefore in relaxation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00172680
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    On the importance of the purity of surfactant solutions in determining their adsorption kinetics (1982)
    Springer
    Colloid & polymer science 260 (1982), S. 1148-1150 
    Details
    ISSN: 1435-1536
    Keywords: Adsorption kinetics ; model of diffusion-kinetic-controlled adsorption ; effect of impurities on adsorption kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract By means of a theoretical experiment it is demonstrated, that a barrier in the adsorption kinetics of a surfactant can be simulated by the presence of surface-active impurities. Hence, the application of models for the diffusion-kinetic-controlled and/or kinetic controlled adsorption presumes the proof of the surface chemical purity of the surfactant solution under investigation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01411238
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    On the theory of adsorption kinetics of ionic surfactants at fluid interfaces (1983)
    Springer
    Colloid & polymer science 261 (1983), S. 335-339 
    Details
    ISSN: 1435-1536
    Keywords: Adsorption kinetics ; ionic surfactants ; influence of the electric double layer ; theory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The influence of the electric field caused by an electric double layer (DL) on the adsorption kinetics of charged surfactant molecules at fluid interfaces is described for the case of high surface potentials and a quasi-equilibrium state of the DL. Known relations for the description of the transport of molecules in the diffusion layer and the DL respectively are used.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01413940
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Adsorption kinetics measurements of some nonionic surfactants (1986)
    Springer
    Colloid & polymer science 264 (1986), S. 357-361 
    Details
    ISSN: 1435-1536
    Keywords: Adsorption kinetics ; ring and plate method ; nonionic surfactants at solution/ air interface
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Dynamic surface tension values of aqueous surfactant solutions were measured by using the ring and plate method. The mean diffusion coefficients calculated on the basis of the purely diffusion controlled adsorption model vary between 2 · 10−6 to 7 · 10−6 cm2/s for all surfactants studied:n-alkanols,n-alkanoic acids, dimethyl and diethyln-alkyl phosphine oxides. That means the surfactants investigated adsorb with a purely diffusion controlled adsorption mechanism and no barriers excist to hinder sorption processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01418196
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    On the application of quantitative models of diffusion-controlled adsorption kinetics at fluid interfaces (1988)
    Springer
    Colloid & polymer science 266 (1988), S. 532-538 
    Details
    ISSN: 1435-1536
    Keywords: Adsorption kinetics ; surfactant transport ; Langmuir isotherm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The model of diffusion-controlled adsorption kinetics can be solved by different mathematical procedures. For the most important case of a Langmuir isotherm, useful solutions are summarized and extended and the ranges of application are given. New approximations are presented which can be applied to most experiments in practice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01420764
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    On the theory of adsorption kinetics of ionic sufactants at fluid interfaces 4. Deceleration of the adsorption rate due to non-equilibrium distribution of adsorbed ions in the diffuse layer (1994)
    Springer
    Colloid & polymer science 272 (1994), S. 548-553 
    Details
    ISSN: 1435-1536
    Keywords: Adsorption kinetics ; ionic surfactants ; non-equilibrium electric double layer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract An approximate analytical solution is obtained for the adsorption kinetics equation derived earlier. On the basis of these relations the importance of the consideration of a non-equilibrium diffuse layer has been shown. To describe the retarded adsorption kinetics the distribution of adsorbed ions in the diffuse layer section of multivalent surfactant ions has been taken into account. The rate of adsorption calculated for a non-ionic surfactant is compared with the adsorption rate for monovalent and bivalent ionic surfactants, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00653220
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Adsorption kinetics of alkyl phosphine oxides in water/alkane systems with transfer across the interface (1997)
    Springer
    Colloid & polymer science 105 (1997), S. 346-350 
    Details
    ISSN: 1435-1536
    Keywords: Adsorption kinetics ; surfactants ; transfer across ; interface ; interfacial tension ; water/hexane ; n-alkyl dimethyl phosphine oxides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The adsorption kinetics of alkyl phosphine oxides soluble both in water and in alkanes has been experimentally studied by measuring the dynamic interfacial tension. To this aim the pendant drop method was used with an automatic acquisition of the drop shape (ASTRA). The experimental results show that under particular geometrical and initial conditions, the dynamic interfacial tension exhibits a minimum. This nonmonotonic behaviour can be explained by considering the transfer of matter through the surface during the adsorption and the depletion of one phase necessary to establish the partition equilibrium. These data can be interpreted on the basis of a diffusion controlled adsorption model involving two finite phases. Moreover a particular experimental procedure for measuring the partition coefficient has been used based on the equilibrium surface tension measurements and on the evaluation of the adsorption isotherm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01188976
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Adsorption kinetics of surfactants from micellar solutions (1981)
    Springer
    Colloid & polymer science 259 (1981), S. 1124-1128 
    Details
    ISSN: 1435-1536
    Keywords: Adsorption kinetics ; surfactants ; micellar solutions ; theory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Zusammenfassung Es wird ein Modell für die diffusionskontrollierte Adsorption von Tensiden aus mizellaren Lösungen angegeben und numerisch gelöst. Das dabei zugrundegelegte Modell für die Mizellkinetik entspricht einem Bildungs-Auflösungs-Mechanismus. Es wird der Einfluß von Parametern wie Mizellkonzentration, Assoziationsgrad, Geschwindigkeitskonstanten der Mizellkinetik auf die Adsorptionskinetik diskutiert.
    Notes: Summary A model of diffusion controlled adsorption of surfactants from micellar solutions is given and numerically solved. The model used to describe the micelle kinetics corresponds to a formation-dissolution mechanism. Parameters like micelle concentration, aggregation number, rate constant of formation or dissolution of micelles influencing the adsorption process are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01524900
    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...