PURPOSE To establish, using adaptive optics scanning laser ophthalmoscopy (AOSLO), that the retinal parafoveal capillary network is altered before the onset of diabetic retinopathy in adult patients with type 2 diabetes. METHODS AOSLO videos were acquired in the parafoveal region of one eye from control subjects and from patients with type 2 diabetes and no retinopathy. Detailed images of the...

The addition of small amounts of a secondary fluid to a suspension can, through the attractive capillary force, lead to particle bridging and network formation. The capillary bridging phenomenon can be used to stabilize particle suspensions and precisely tune their rheological properties. This effect can even occur when the secondary fluid wets the particles less well than the bulk fluid. These...

Microvascular changes during the development of follicles in bovine ovaries were studied by scanning electron microscopy of corrosion casts. A clear vascular plexus of ovarian follicles appeared at the stage when secondary follicles were 200-400 microns in diameter. The plexus consisted initially of a thin, roughly structured and single-layered capillary network. During follicular development, ...

In an effort to engineer capillary-like networks in vitro, different cultivation methods were compared. Five small-diameter tube-like constructs ('vessel equivalents') were fabricated from porcine gelatin scaffolds and seeded with human adipose tissue stromal cells and umbilical vein endothelial cells. After initial growth, the vessel equivalents were divided. One segment was exposed to pulsati...

Accurate permeability estimation has always been a concern in determining flow units, assigning appropriate capillary pressure andrelative permeability curves to reservoir rock types, geological modeling, and dynamic simulation.Acoustic method can be used as analternative and effective tool for permeability determination. In this study, a four-step approach is proposed for permeability estimati...

The capillary network in the ventricular myocardium in man consists of 2 sphincter-type capillaries (the metarteriole and the precapillary) and a nonmuscular capillary, the classic or true capillary. The muscular components of the metarterioles and of the precapillaries are innervated by nerve fibers of which the terminal structure ends as a knotted fibrillar process near the muscle nucleus. Th...

An understanding of cardiac health and disease requires knowledge of the various factors that control coronary capillary blood flow. An analysis of coronary capillary blood flow based on a complete set of actual data on the capillary anatomy and elasticity does not exist. Previously, a complete set of data on the branching pattern and the vascular geometry of the pig coronary capillary network ...

In this work a glass micromodel which its grains and pores are non-uniform in size, shape and distribution is considered as porous medium. A two-dimensional random network model of micromodel with non-uniform pores has been constructed. The non-uniformity of porous model is achieved by assigning parametric distribution functions to pores throat and pores length, which was measured using ima...

Peripheral circulation can be divided in two components: continuous one, which includes continual fluctuation of muscular vessels diameters; and discrete one, which is caused by opening and closing of pre-capillary sphincters causes the activation-deactivation of capillaries. The state of each capillary sphincter depends on concentration of tissues vasodilator metabolites in the neighborhood of...