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Intussusceptive angiogenesis, also known as splitting angiogenesis, is the formation of a new blood vessel by splitting an existing blood vessel into two. Intussusception was first observed in neonatal rats. In this type of vessel formation, the capillary wall extends into the lumen to split a single vessel in two. There are four phases of ...
Time-lapse of growth of a citric acid crystal. The video covers an area of 2.0 by 1.5 mm and was captured over 7.2 min. The crystallization process consists of two major events, nucleation and crystal growth which are driven by thermodynamic properties as well as chemical properties.
Vascular endothelial growth factor (VEGF, / v ɛ dʒ ˈ ɛ f /), originally known as vascular permeability factor (VPF), [1] is a signal protein produced by many cells that stimulates the formation of blood vessels. To be specific, VEGF is a sub-family of growth factors, the platelet-derived growth factor family of cystine-knot growth factors.
Neovascularization is the natural formation of new blood vessels (neo-+ vascular + -ization), usually in the form of functional microvascular networks, capable of perfusion by red blood cells, that form to serve as collateral circulation in response to local poor perfusion or ischemia.
For perceptible growth rates, this mechanism requires a finite driving force (or degree of supercooling) in order to lower the nucleation barrier sufficiently for nucleation to occur by means of thermal fluctuations. [5] In the theory of crystal growth from the melt, Burton and Cabrera have distinguished between two major mechanisms: [6] [7] [8]
Vasculogenesis, in contrast, is when endothelial precursor cells (angioblasts) migrate and differentiate in response to local cues (such as growth factors and extracellular matrices) to form new blood vessels. These vascular trees are then pruned and extended through angiogenesis.
The growth of tumours often results in reactivation of blood vessel growth and vascular remodelling in order to perfuse the new tissue with blood and sustain its proliferation. [2] Tumour growth has been shown to be self-organizing and to behave more similarly to embryonic tissues than to adult tissues. [ 24 ]
Corneal neovascularization (CNV) is the in-growth of new blood vessels from the pericorneal plexus into avascular corneal tissue as a result of oxygen deprivation. [1] Maintaining avascularity of the corneal stroma is an important aspect of healthy corneal physiology as it is required for corneal transparency and optimal vision.