BACKGROUND There is no consensus in the literature as to which point of the radial artery (RA) is the safest to attempt vascular access. The purpose of this study was to measure the diameter, tortuosity and branching patterns of the distal RA. MATERIALS AND METHODS 140 cadaveric RAs (66 male, 74 female) were dissected and measured. The external diameter of the RA was measured at 2 cm incremen...

Serum apolipoprotein (apo)AI and -B have been shown to be associated with diabetic retinopathy, but the underlying mechanisms are unclear. We investigated whether apoAI and apoB levels are associated with measures of systemic and retinal microvascular function in patients with diabetes. We recruited 224 diabetic patients (85 type 1 and 139 type 2) and assessed serum lipids and lipoproteins from...

Subsurface migration of greenhouse gases and other gaseous phase contaminants is predominantly controlled by soil gas diffusion coefficient (Dp) and its variations with soil-air content (ε) and soil moisture (or potential) status. Buckingham (1904) stated that Dp is proportional to ε X with X characterizing the tortuosity and connectivity of air-filled pore space. In the Buckingham model, as we...

In order to examine basic properties of release from and through wax matrix layer, reservoir device matrix tablet was prepared from a physical mixture of hydrogenated caster oil and drug that was the same one in the reservoir. Release process could be divided into two stages. The first stage was the formation process of water channel by dissolving the drug in the wax matrix layer, and dissolved...

The extracellular space (ECS) of the brain is a thin region surrounding each cell that is filled with a medium resembling cerebrospinal fluid and an unknown amount of extracellular matrix. The ECS is difficult to study but diffusion measurements based on a point-source diffusion paradigm have begun to reveal the complex structure of this region. Despite the complexity, a modified version of Fic...

The present study carefully examined entropy generation during wustite pellet reduction to sponge iron. The finite volume method was used to solve the governing equations. The grain model was used to simulate the reaction rate. The reactant gases including carbon monoxide and hydrogen were converted to water and carbon dioxide after wustite reduction. Entropy is generated by heat transfer, mass...

BACKGROUND Tortuous coronary arteries are commonly observed in clinical screenings and it may cause a reduction of the coronary pressure. However, whether this reduction leads to significant decreasing in the coronary blood supply is still unknown. The purpose of this study was to investigate the effect of the coronary tortuosity (CT) on the coronary blood supply. METHOD A computational fluid...

PURPOSE To study the effects of vascular endothelial growth factor (VEGF) on endothelial nitric oxide synthetase (eNOS) and retinal vascular tortuosity and cleavage planes in a rat model of retinopathy of prematurity (ROP). METHODS Within 4 hours of birth, pups and mothers were cycled between 50% and 10% oxygen daily. At postnatal day (p)12, pups received either intravitreous anti-rat neutral...

OBJECTIVE The structure of the collagen scar during healing of a myocardial infarction is a determinant of the function of the remodeled tissue. We hypothesize that the passive deformations of both scar and normal tissue are related to the underlying collagen uncoiling as the tissue stretches, and that the unloaded tortuosity of the collagen may be a determinant of tissue stiffness at low ventr...

The objective of this study was to investigate the effects of capillary network anastomoses and tortuosity on oxygen transport in skeletal muscle, as well as the importance of muscle fibers in determining the arrangement of parallel capillaries. Countercurrent flow and random capillary blockage (e.g. by white blood cells) were also studied. A general computational model was constructed to simul...