Influence of pH on Adenosine-Induced Dilatations of Pial Arteries

1976 ◽  
pp. 141-144 ◽  
Author(s):  
M. Wahl ◽  
W. Kuschinsky
Keyword(s):  
Pial Arteries ◽  
Influence Of Ph

Microvascular features that suggest effectors of blood-flow regulation in the brain: Evidence by SEM of corrosion casts of intracerebral vessels

1990 ◽  
Vol 48 (3) ◽  
pp. 274-275
Author(s):  
Enrico D.F. Motti ◽  
Hans-Georg Imhof ◽  
Gazi M. Yasargil
Keyword(s):  
Blood Flow ◽  
Perfusion Pressure ◽  
Corrosion Casts ◽  
Cerebral Microcirculation ◽  
Pial Arteries ◽  
Random Occurrence ◽  
Brain Arteries ◽  
Homogeneous Network ◽  
The Brain

Physiologists have devoted most attention in the cerebrovascular tree to the arterial side of the circulation which has been subdivided in three levels: 1) major brain arteries which keep microcirculation constant despite changes in perfusion pressure; 2) pial arteries supposed to be effectors regulating microcirculation; 3) intracerebral arteries supposed to be deprived of active cerebral blood flow regulating devices.The morphological search for microvascular effectors in the cerebrovascular bed has been elusive. The opaque substance of the brain confines in vivo investigation to the superficial pial arteries. Most morphologists had to limit their observation to the random occurrence of a favorable site in the practically two-dimensional thickness of diaphanized histological sections. It is then not surprising most investigators of the cerebral microcirculation refer to an homogeneous network of microvessels interposed between arterioles and venules.We have taken advantage of the excellent depth of focus afforded by the scanning electron microscope (SEM) to investigate corrosion casts obtained injecting a range of experimental animals with a modified Batson's acrylic mixture.

Influence of pH on the Migration of Various Forms of Metals in the "Bottom Sediments - Water" System under Experimental Conditions

2009 ◽  
Vol 45 (3) ◽  
pp. 92-100 ◽  
Author(s):  
P. N. Linnik ◽  
A. V. Zubko ◽  
I. B. Zubenko ◽  
I. I. Ignatenko ◽  
L. A. Malinovskaya
Keyword(s):  
Bottom Sediments ◽  
Water System ◽  
Experimental Conditions ◽  
Influence Of Ph

Influence of pH Value on the Performance of Composite Films Prepared from Chromium Residue by Hydrothermal Method

2013 ◽  
Vol 28 (4) ◽  
pp. 387-392
Author(s):  
Tong SUN ◽  
Lian-Li LIU ◽  
Shu-Ying XU ◽  
Xiao-Lin PENG ◽  
Hai-Long YANG
Keyword(s):  
Hydrothermal Method ◽  
Ph Value ◽  
Composite Films ◽  
Influence Of Ph

Using microbial fatty acids to quantify, characterize and compare biofilm and suspended microbial populations in wastewater treatment systems

1998 ◽  
Vol 38 (4-5) ◽  
pp. 273-280 ◽  
Author(s):  
A. G. Werker ◽  
E. R. Hall
Keyword(s):  
Fatty Acid ◽  
Methyl Esters ◽  
Ph Control ◽  
Microbial Populations ◽  
Total Organic Carbon Removal ◽  
Operating Limits ◽  
Suspended Biomass ◽  
Kraft Mill Effluent ◽  
Microbial Fatty Acid ◽  
Influence Of Ph

Spectra of microbial fatty acid methyl esters were used to assess the influence of pH on the biofilm and suspended biomass populations within bench scale moving bed bioreactors treating bleached kraft mill effluent. The fatty acid spectral data were reduced by logcontrast canonical component analysis. The first canonical component differentiated biofilm from suspended populations and the second two appeared to indicate an influence of pH on microbial ecology. Thus, the biofilm and suspended microbial communities were distinct, as were the populations acclimated at pH 6 and pH 8. Experimental data for total organic carbon removal suggested that the more recalcitrant fraction of the influent was consumed by the slower growing, high SRT biofilm fraction of the biomass. Since the biofilm ecology was sensitive to pH within typical pH operating limits of full-scale systems, tighter pH control might improve treatment reliability in the event of process transients.

Kinetics and mechanism of redox reactions of U(III) ions with monochloroacetic and dichloroacetic acids

1979 ◽  
Vol 44 (2) ◽  
pp. 401-405 ◽  
Author(s):  
Ľubica Adamčíková ◽  
Ľudovít Treindl
Keyword(s):  
Redox Reactions ◽  
Reaction Rate ◽  
Activation Parameters ◽  
Outer Sphere ◽  
Alcohol Concentration ◽  
Kinetics And Mechanism ◽  
Solvent Structure ◽  
Influence Of Ph ◽  
Sphere Mechanism

The kinetics and mechanism of the redox reactions of U3+ ions with mono- and dichloroacetic acids were studied. The influence of pH was observed mainly in the second case and led to the determination of the rate constants and activation parameters corresponding to two parallel steps, namely oxidation of U3+ with CHCl2COO- ions and oxidation of U3+ with CHCl2.COOH molecules. The influence of binary mixtures of water with methanol, ethanol, isopropanol, or tert-butenol on the reaction rate was followed. Increasing alcohol concentration influences the rate constant not only through changing dielectric constant and solvation of the reactants but also through a change of the solvent structure which plays a role in reactions with an outer sphere mechanism of the electron transfer.

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