ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

The zero of potential of the electrical field produced by the heart beat is defined and measured as the average value over the surface of a large spherical, integrating electrode which contains the subject and a homogeneous conducting medium. The Zero of potential thus defined is apparently free of assumptions of any kind and is used to evaluate the error on the three-branch and the four-branch central terminal with equal resistances. The latter may, in certain instances, be brought to zero by using unequal resistances. The potential function at its electrodes is that of an unweighted resultant vector or a point dipole. The electrodes which contribute to its potential are remote.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

From determinations of radioactivity and potassium content at intervals after the injection of Rb86, it was inferred that most organs of the dog contained exchangeable rubidium in a concentration paralleling but exceeding that of potassium, as compared with their relative concentrations in the plasma. A “lag phenomenon” resulting in higher rubidium specific activity in the myocardium than plasma was present. Analysis indicated that this was dependent on the relationship of myocardial rubidium exchange rate and the rate of decline of plasma rubidium specific activity. In experiments requiring prolonged observation, Rb86(half life, 19.5 days) is a useful tracer of potassium.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

Infusion of cortisone and related compounds in the normal dog under standardized conditions resulted in increased voltage and peaking of the T wave of the electrocardiogram. These alterations were not associated with significant changes in the plasma electrolytes. Plasma inorganic phosphate decreased and urinary phosphate excretion increased. Cortisone appears to alter ventricular repolarization, but the mechanism of the effect is unknown.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

The theory of dynamic fluid motion involving the forces manifested by mass, acceleration, viscous friction and vessel wall tension have been considered and studied when arterial blood flow and pressure are pulsatile. These studies and considerations have resulted in the conclusion that arterial blood pressure is dependent upon all of these parameters and that the relationship of pressure and flow is more complex and nonlinear than heretofore generally believed.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

The distensibility of the aorta was measured in anesthetized dogs by injecting blood at controlled rates into an isolated segment. Constrictor drugs produce a moderate increase in distensibility of the aorta at low pressure ranges and a more marked increase in distensibility at normal pressures. Studies of the splanchnic venous system of intestinal loops by the same method, and also by a method which does not require interruption in blood flow, gave evidence of the same type of distensibility phenomena as seen in the aorta, although at low pressures the venous distensibility tends to be actually decreased by vasoconstriction. The splanchnic venous system also differs from the aorta in that it is very dependent upon the rate of pressure-volume change. These results are analyzed in terms of the basic mechanisms involved and their physiologic implications.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

The responses of the vascular beds in skeletal muscle and skin to changes in blood pH on the acid and alkaline sides of the physiologic range were compared. Dilatation occurred in both cutaneous and muscular beds when the blood pH was shifted to the acid range. Dilatation also occurred in the muscle beds when the blood pH was shifted to the alkaline range but such change in blood pH caused vasoconstriction in skin.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

A method has been devised for directly measuring hepatic outflow in dogs so as to permit simultaneous comparison with the indirect method, employing the hepatic removal of Bromsulphalein (BSP). The results show that the indirect method averages 7.3 per cent higher than the direct. This difference is attributed to a small Degrees of extrahepatic removal of the dye.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

Mixed soybean sterols (80 per cent sitosterols) were fed to rats simultaneously with cholesterol in acute and chronic experiments. In acute experiments, concurrent feeding of a test dose of soybean sterols and cholesterol did not diminish the usual fraction of cholesterol absorption into the thoracic duct lymph. In chronic experiments the addition of 2 or 10 per cent soybean sterols to a diet which induces chronic hypercholesteremia in rats failed to inhibit the development or magnitude of chronic hypercholesteremia.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

The particle size distribution of the Sf30 “class” of serum lipoprotein was determined by the electron microscope. Most of the lipoprotein molecules are not spherical but have the shape of ellipsoids of rotation with an axis ratio of 1.5. The molecules of a homogeneous flotation “class” show differences in the reactivity of their lipid moiety demonstrated by their staining properties with osmium tetroxide.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID