Normal rat liver and brain slice respiration was studied at 37 °C by the polarographic technique of Longmuir in the presence of oxygenated solutions and with addition of clinical concentrations of halothane to the mixtures. In the presence of oxygen alone, passive and facilitated diffusion seem responsible for the transport of oxygen in both tissues. In presence of halothane, the passive diffus...

BACKGROUND Acute ischemic stroke is common and disabling, but there remains a paucity of acute treatment options and available treatment (thrombolysis) is underutilized. Advanced brain imaging, designed to identify viable hypoperfused tissue (penumbra), could target treatment to a wider population. Existing magnetic resonance imaging and computed tomography-based technologies are not widely use...

Shape is one of the most important determinants of the properties of microstructures. Despite of a recent progress on microfabrication techniques, production of three-dimensional micro-objects are yet to be fully achieved. Nature uses reaction-diffusion process during bottom-up self-assembly to create functional shapes and patterns with high complexity. Here we report a method to produce polyme...

The free radicals produced by g irradiation in the polymer network are formed with ionizing radiation. The decay rates of radicals in the temperature range were used to estimate the diffusion coefficient of oxygen into polymeric spheres by an electron spin resonance (ESR) technique. The ESR results showed that the activation energy of the diffusion of oxygen into poly(methyl methacrylate) (PMMA...

Oxygen is an important element for plant growth. Reducing its concentration in the soil affects plant physiological processes such as nutrient and water uptake as well as respiration, the redox potential of soil elements and the activity of microorganisms. The main mechanism of oxygen transport in the soil is by diffusion, a dynamic process greatly influenced by soil physical properties such as...

The transport resistance of oxygen in a PEMFC flow field and gas diffusion layer interface was numerically investigated in a 3D model. This model solved for the convection of air and the diffusion of oxygen in the air in a single flow field channel. The interfacial oxygen transport resistance was expressed with the Sherwood number. For a dry channel, the numerically obtained Sherwood number was...

We present the results of large scale computer simulations in which we investigate the static and dynamic properties of sodium disilicate and sodium trisilicate melts. We study in detail the static properties of these systems, namely the coordination numbers, the temperature dependence of the Q(n) species and the static structure factor, and compare them with experiments. We show that the struc...

The heart and those striated muscles that contract for long periods, having available almost limitless oxygen, operate in sustained steady states of low sarcoplasmic oxygen pressure that resist change in response to changing muscle work or oxygen supply. Most of the oxygen pressure drop from the erythrocyte to the mitochondrion occurs across the capillary wall. Within the sarcoplasm, myoglobin,...

Objective: To assess the hypothesis that a cholesterol-lowering regimen with simvastatin would improve red blood cell (RBC) oxygen diffusion, and that such improvement would correlate with the intensity of anginal symptoms and with exercise electrocardiogram (ECG) changes. Methods: Desaturated venous blood samples from 18 hypercholesterolemic volunteer subjects with exertional chest pain were c...

The increased workload of the right heart due to pulmonary hypertension increases oxygen consumption of right ventricular cardiomyocytes because the mitochondria have to operate at a higher rate. Hypertrophy can normalize right ventricular wall stress, thereby also normalizing the rate of oxygen consumption by mitochondria. However, hypertrophy may cause hypoxia in cardiomyocytes because intrac...