11,286 research outputs found
Recommended from our members
The roles of endoglin gene in cerebrovascular diseases.
Endoglin (ENG, also known as CD105) is a transforming growth factor β (TGFβ) associated receptor and is required for both vasculogenesis and angiogenesis. Angiogenesis is important in the development of cerebral vasculature and in the pathogenesis of cerebral vascular diseases. ENG is an essential component of the endothelial nitric oxide synthase activation complex. Animal studies showed that ENG deficiency impairs stroke recovery. ENG deficiency also impairs the regulation of vascular tone, which contributes to the pathogenesis of brain arteriovenous malformation (bAVM) and vasospasm. In human, functional haploinsufficiency of ENG gene causes type I hereditary hemorrhagic telangiectasia (HHT1), an autosomal dominant disorder. Compared to normal population, HHT1 patients have a higher prevalence of AVM in multiple organs including the brain. Vessels in bAVM are fragile and tend to rupture, causing hemorrhagic stroke. High prevalence of pulmonary AVM in HHT1 patients are associated with a higher incidence of paradoxical embolism in the cerebral circulation causing ischemic brain injury. Therefore, HHT1 patients are at risk for both hemorrhagic and ischemic stroke. This review summarizes the possible mechanism of ENG in the pathogenesis of cerebrovascular diseases in experimental animal models and in patients
Timescale Spectra in High Energy Astrophysics
A technique of timescale analysis performed directly in the time domain has
been developed recently. We have applied the technique to studying rapid
variabilities of hard X-rays from neutron star and black hole binaries,
gamma-ray bursts and terrestrial gamma-ray flashes. The results indicate that
the time domain method of spectral analysis is a powerful tool in revealing the
underlying physics in high-energy processes in objects.Comment: 7 pages, 4 figures. Invited talk at the 6th Pacific Rim Conference on
Steller Astrophysic
Thermodynamics of phase transition in higher dimensional Reissner-Nordstr\"{o}m-de Sitter black hole
It is well known that there are black hole and the cosmological horizons for
the Reissner-Nordstr\"{o}m-de Sitter spacetime. Although the thermodynamic
quantities on the horizons are not irrelevant, they satisfy the laws of black
hole thermodynamics respectively. In this paper by considering the relations
between the two horizons we give the effective thermodynamic quantities in
-dimensional Reissner-Nordstr\"{o}m-de Sitter spacetime. The
thermodynamic properties of these effective quantities are analyzed, moreover,
the critical temperature, critical pressure and critical volume are obtained.
We carry out an analytical check of Ehrenfest equations and prove that both
Ehrenfest equations are satisfied. So the spacetime undergoes a second order
phase transition at the critical point. This result is consistent with the
nature of liquid--gas phase transition at the critical point, hence deepening
the understanding of the analogy of charged dS spacetime and liquid--gas
systems.Comment: 18 pages, 7 figures, 1 tabl
- …