19 research outputs found
QUINTESSENCE AND PHANTOM ENERGY INHOMOGENEITIES AT LATE STAGES OF UNIVERSE EVOLUTION
As it directly follows from the scalar perturbations, applied to the late stages of evolution of the Universe, filled with dark energy, nonrelativistic matter and, possibly, quintessence or phantom energy, the last two components can not be homogeneous. We demonstrate that 蠅=-1/3 is only admissible negative parameter in the non-vacuum equation of state, determine the corresponding gravitational potentials and discuss their main properties
COSMOLOGICAL PERTURBATIONS IN PRESENCE OF SCALAR FIELDS
We investigate the role of the scalar field assuming its presence at late stages of the Universe evolution together with dust presented by a system of an arbitrary number of gravitating masses (galaxies, groups of galaxies and clusters of galaxies) and the cosmological constant in the framework of the theory of scalar cosmological perturbations. In particular,we discuss the case of the homogeneous scalar field and its possible influence on the gravitational potentials representing metric perturbations. We also focus attention on the interconnection between the astrophysical problem and the cosmological one in thescalar field presence.We investigate the role of the scalar field assuming its presence at late stages of the Universe evolution together with dust presented by a system of an arbitrary number of gravitating masses (galaxies, groups of galaxies and clusters of galaxies) and the cosmological constant in the framework of the theory of scalar cosmological perturbations. In particular,we discuss the case of the homogeneous scalar field and its possible influence on the gravitational potentials representing metric perturbations. We also focus attention on the interconnection between the astrophysical problem and the cosmological one in thescalar field presence
Early postoperative hemodynamic performances of stented versus stentless aortic xenografts in aortic valve replacement in elderly patients: a comparative study
BACKGROUND AND AIM: Surgical valve replacement is the most commonly performed for aortic stenosis. Randomized trials comparing stentless to stented bioprostheses for aortic valve replacement in elderly are scarce. The aim of our study was comparing and evaluating the early hemodynamic performances of Hancock (TM) stented and FreeStyle (TM) stentless xenograft aortic valves in aortic valve replacement in elderly patients
The effect of Amifostine (Ethyol) on intestinal anastomosis in rats with radiation enteritis
BACKGROUND: Preoperative radiotherapy in colorectal cancers is being used as an adjuvant therapy with increasing frequency. Postoperative complications in early and late periods in various ratios are reported. It has also been shown that radiation has a delaying effect on wound healing and this effect is dose-dependent