Capillary Configuration Research Articles

Lung tissue plasticity: Morphometric analysis of anisotropic strain in liquid filled lungs

Lungs of rats were fixed at different inflation pressures (Ptp) during liquid filling with the pulmonary vessels tied to prevent vascular volume change after fixation had begun. Morphometric analysis showed that alveolar surface varied as alveolar volume (Va) to the power 0.82, while the arithmetic mean tissue thickness varied as Va −0.2. This is interpreted as evidence for anisotropic expansion. Capillary volume (Vc) was found to increase from zero Ptp to a maximum at Ptp = 2 cm H 2O then decrease as Va increased. Morphometric diffusion capacity of the membrane component increased as Va 0.59 while that for whole lung (D l) paralleled the change in Vc. Alveolar capillary tissue unfolding is described as the main factor accounting for anistropic expansion of alveolar surface and for capillary configuration. The absolute values of Vc and D l were lower by 60% and 50%, respectively, compared with values obtained by standard instillation fixation methods and this is suggested could account for previous discrepancies between morphometric and physiologic estimates of D l.

A Comparison of Semipermeable Microcapsules and Standard Dialysers for Use in Separation

Abstract Dialysers with membranes of the coil, plate, or capillary configurations are most commonly used in separation procedures. Inrecent years, there is the development of a new class of dialys is system in the form of semipermeable microcapsules (1,2,3, 4). It is the purpose of this paper to discuss this new dialys is system and to compare it with standard dialysers.

A single unit microelectrode with a glass seal and a microhole.

A method is presented for the construction, calibration and utilization of a single unit ion-selective microelectrode of the internal capillary configuration. The microelectrode is ideally suited for in situ applications. The microelectrode capacity can be made as small as 10 nanoliters. It is superior to previously constructed microelectrode cells in that it combines the ion-selective and the reference electrodes into one physical unit.

Glutamylcholine in the treatment of hypertension.

Glutamylcholine was administered in 158 cases of hypertension and the results presented below were obtained.1. There was a marked improvement in subjective symptoms and blood pressure.2. The capillary resistance which was at an average level of 26mm Hg prior to treatment, showed an average rise of 37mm Hg after treatment.3. The capillary configuration was examined. Following treatment, there was an acceleration of blood flow and dilation and elongation of the arterial loop.4. The blood picture showed little change.5. A slight decrease in viscosity of the serum was noted.6. There was no worsening in the eyegrounds during the period of treatment.7. Electrocardiographic examinations showed a large number with left ventricular changes and improvement was observed after treatment. There were no detrimental effects on the cardiac muscle.8. The pressure which once dropped to normal levels gradually rose again. This took place in the majority of cases in 2-4 weeks.9. Serum total protein, albumin and protein quotient were reduced and globulin slightly increased but a tendency to recovery appeared after 8 weeks of treatment.10. The total lipid level of the serum was in the upper limits of normal values and at 4 weeks of treatment, a further rise was apparent, but in 8 weeks a trend toward decrease was seen.11. Examination of the serum cholesterol showed that the free form was unchanged, whereas the total and esterified were increased, which however decreased following treatment.12. The serum chlorine content was increased, but in the cases in which GlC was definitely effective, there was a decrease following treatment.13. Serum sodium level rose, but fell following treatment, especially in cases which responded poorly.14. The serum potassium level rose, but fell following treatment and the calcium which was reduced, increased after treatment.15. Serum cholinesterase was increased, but following the administration of GlC, returned to normal levels.

Water conduction from shallow water tables

does not appear. First page follows. Introduction The phenomenon of the flow of liquids through porous mediums without the application of external force and without complete filling of the pores of the solid with liquid, has long been recognized and studied. It was early recognized that the forces involved are those of adhesion and cohesion, the same as those responsible for the action of liquids in capillary tubes. The term “capillarity” (6), (17)4 has thus come to apply to the flow of liquids through porous mediums. Many analyses (28)-(31) have been made for the purpose of evaluating the capillary forces acting in three-phase systems, such as is the case in moist soil, consisting of solid, liquid, and gas, by assuming spherical solid particles of uniform size and sequence of packing arrangement. While this assumption has presented concepts of value in comprehending the mechanism involved in capillary flow, the size and configuration of the solid and liquid phases are very complex in even the most idealized systems, and become indeterminate when applied to natural bodies such as soil. The capillary potential concept, introduced by Buckingham (6) in 1907, assumed a capillary force field generated by the attraction of moist soil for water. He defined a capillary potential, the gradient of which is equal in magnitude to the capillary force.