scholarly journals On homogeneous decomposition spaces and associated decompositions of distribution spaces

2019 ◽  
Vol 292 (12) ◽  
pp. 2496-2521
Author(s):  
Zeineb Al‐Jawahri ◽  
Morten Nielsen
Keyword(s):  
Decomposition Spaces ◽  
Distribution Spaces ◽  
Homogeneous Decomposition

scholarly journals Direct Chemical Measurement of the λ of the Lumped Constant of the [14C]Deoxyglucose Method in Rat Brain: Effects of Arterial Plasma Glucose Level on the Distribution Spaces of [14C]Deoxyglucose and Glucose and on λ

1989 ◽  
Vol 9 (3) ◽  
pp. 304-314 ◽  
Author(s):  
Kentaro Mori ◽  
Nancy Cruz ◽  
Gerald Dienel ◽  
Thomas Nelson ◽  
Louis Sokoloff
Keyword(s):  
Plasma Glucose ◽  
Glucose Concentration ◽  
Severe Hypoglycemia ◽  
Plasma Glucose Concentration ◽  
Operational Equation ◽  
Chemical Measurements ◽  
Lumped Constant ◽  
Dg Method ◽  
Arterial Plasma ◽  
Distribution Spaces

The lumped constant in the operational equation of the 2-[14C]deoxyglucose (DG) method contains the factor λ that represents the ratio of the steady-state tissue distribution spaces for [14C]DG and glucose. The lumped constant has been shown to vary with arterial plasma glucose concentration. Predictions based mainly on theoretical grounds have suggested that disproportionate changes in the distribution spaces for [14C]DG and glucose and in the value of λ are responsible for these variations in the lumped constant. The influence of arterial plasma glucose concentration on the distribution spaces for DG and glucose and on λ were, therefore, determined in the present studies by direct chemical measurements. The brain was maintained in steady states of delivery and metabolism of DG and glucose by programmed intravenous infusions of both hexoses designed to produce and maintain constant arterial concentrations. Hexose concentrations were assayed in acid extracts of arterial plasma and freeze-blown brain. Graded hyperglycemia up to 28 m M produced progressive decreases in the distribution spaces of both hexoses from their normoglycemic values (e.g., ∼ – 20% for glucose and – 50% for DG at 28 m M). In contrast, graded hypoglycemia progressively reduced the distribution space for glucose and increased the space for [14C]DG. The values for λ were comparatively stable in normoglycemic and hyperglycemic conditions but rose sharply (e.g., as much as 9–10-fold at 2 m M) in severe hypoglycemia.

A procedure for measurement of distribution spaces in isolated fat cells

1972 ◽  
Vol 286 (1) ◽  
pp. 1-9 ◽  
Author(s):  
J. Gliemann ◽  
K. Østerlind ◽  
J. Vinten ◽  
S. Gammeltoft
Keyword(s):  
Fat Cells ◽  
Isolated Fat Cells ◽  
Distribution Spaces

Gas phase interaction with catalytic oxidation reactions

1972 ◽  
Vol 326 (1565) ◽  
pp. 215-227 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Maleic Anhydride ◽  
Catalytic Oxidation ◽  
Gas Phase ◽  
Major Part ◽  
Oxidation Reactions ◽  
Mixed Gas ◽  
Kinetics Of ◽  
Oxidation Of Benzene ◽  
Homogeneous Decomposition

Studies of the catalytic oxidation of benzene to maleic anhydride and carbon dioxide over vanadia/molybdena catalysts show that the major part of the reaction involves interacting gas and gas-solid processes. The results are consistent with a mechanism in which a benzeneoxygen adduct is formed catalytically, desorbs and then reacts to give maleic anhydride entirely in the gas phase. On the basis of this proposed mechanism, the kinetics of individual reactions have been investigated in some depth. The over-oxidation of maleic anhydride has been found to be not significant under the conditions of reaction. The kinetic relationships governing the homogeneous decomposition of the adduct and the oxidation of the adduct to maleic anhydride and to carbon dioxide have been established. The results show that essentially all of the anhydride originates from mixed gas-solid/gas reaction while substantial amounts of carbon dioxide are produced entirely catalytically.

Extrathyroidal Effects of Low Concentrations of Thiourea on Rainbow Trout, Salmo gairdneri

1981 ◽  
Vol 38 (10) ◽  
pp. 1283-1285 ◽  
Author(s):  
J. G. Eales
Keyword(s):  
Rainbow Trout ◽  
Chronic Exposure ◽  
Degradation Rate ◽  
Salmo Gairdneri ◽  
Low Concentrations ◽  
Direct Sensitivity ◽  
Distribution Spaces ◽  
Circulating Levels

Chronic exposure of fed immature rainbow trout (Salmo gairdneri) to a low ambient thiourea (TU) concentration did not depress circulating levels of T4 (thyroxine) or triiodothyronine, T4 degradation rate, or T4 deiodination rate indicating no significant T4 influence on thyroidal hormone output. However, TU increased the hematocrit and decreased distribution spaces for iodide and T4, indicating direct sensitivity of extrathyroidal processes to TU.Key words: thiourea, thyroxine, hematocrit, iodide metabolism, rainbow trout

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