151 research outputs found
The Near-Horizon Limit of the Extreme Rotating d=5 Black Hole as a Homogenous Spacetime
We show that the spacetime of the near-horizon limit of the extreme rotating
d=5 black hole, which is maximally supersymmetric in N=2,d=5 supergravity for
any value of the rotation parameter j in [-1,1], is locally isomorphic to a
homogeneous non-symmetric spacetime corresponding to an element of the
1-parameter family of coset spaces SO(2,1)x SO(3)/SO(2)_j in which the subgroup
SO(2)_j is a combination of the two SO(2) subgroups of SO(2,1) and SO(3).Comment: Some points clarified and misprints corrected. Version to be
published in Classical and Quantum Gravit
Leu208Val and Ile181Leu variants of cytochrome P450 CYP2C9 are not related to the acenocoumarol dose requirement in a Spanish population
The c.-1639G > A polymorphism of the VKORC1 gene is a major determinant of the response to acenocoumarol in anticoagulated patients
Much of the variability in the sensitivity to warfarin in anticoagulated patients is associated with the c.-1639G > A polymorphism of the vitamin K-epoxide reductase (VKORC1) gene. However, its association with the acenocoumarol dose in patients under anticoagulant therapy has not been studied. The c.-1639G > A genotype of VKORC1 was determined in 113 patients on stable anticoagulation requiring low (n = 42), medium (n = 42) or high (n = 21) acenocoumarol doses. To evaluate the association between acenocoumarol requirements and the c.-1639G > A variant, multivariate logistic regression models were fitted, adjusting for age, gender, and the c.430C > T and c.1075A > C variants of cytochrome P450 2C9 (CYP2C9). A total of 90.5% of the patients in the low acenocoumarol dose group carried the A allele of VKORC1:c.-1639G > A. The A allele independently increased the odds of requiring a low acenocoumarol dose [odds ratio (OR) 9.4; 95% confidence interval (CI) 1.9-46.4; P = 0.006], especially when the homozygous form was present (OR 44.2; 95% CI 5.5-354.6; P A polymorphism of VKORC1 is therefore associated with a low-dose requirement for acenocoumarol in patients receiving anticoagulant therapy
Domain walls without cosmological constant in higher order gravity
We consider a class of higher order corrections with arbitrary power of
the curvature tensor to the standard gravity action in arbitrary space-time
dimension . The corrections are in the form of Euler densities and are
unique at each and . We present a generating functional and an explicit
form of the corresponding conserved energy-momentum tensors. The case of
conformally flat metrics is discussed in detail. We show that this class of
corrections allows for domain wall solutions since, despite the presence of
higher powers of the curvature tensor, the singularity structure at the wall is
of the same type as in the standard gravity. However, models with higher order
corrections have larger set of domain wall solutions and the existence of these
solutions no longer depends on the presence of cosmological constants. We find
for example that the Randall-Sundrum scenario can be realized without any need
for bulk and/or brane cosmological constant.Comment: latex, 10 pages, introduction extended, references added, typos
correcte
Differential effects of 2C9*3 and 2C9*2 variants of cytochrome P-450 CYP2C9 on sensitivity to acenocoumarol
The 2C9*3 and 2C9*2 polymorphisms of cytochrome P-450 CYP2C9 are associated with hypersensitivity to warfarin and bleeding. The effect of these polymorphisms on sensitivity to acenocoumarol is unknown. Three groups of patients, with low, medium, or high acenocoumarol-dose requirements, were studied. Age influenced the acenocoumarol sensitivity. Bearing the 2C9*3 allele was associated with the need for a lower acenocoumarol dose (odds ratio [OR], 6.02; 95% confidence interval [CI], 1.50-24.18); 80% of carriers of the 2C9*3 allele required a low dose. The 2C9*2 allele was associated with a lower acenocoumarol-dose requirement (OR, 2.70; 95% CI, 1.11-6.58) because of a reduced risk of the need for a high acenocoumarol dose (4.8% of the patients in the high-dose group carried the 2C9*2 allele versus 34.1% and 30.2%, respectively, in the medium-dose and low-dose groups). Therefore, carriers of 2C9*3 may need a low initial loading dose of acenocoumarol. Because acenocoumarol sensitivity with the 2C9*2 variant does not seem to be clinically relevant, the drug could be an alternative to warfarin in 2C9*2 carrier
Thick de Sitter 3-Branes, Dynamic Black Holes and Localization of Gravity
The embedding of a thick de Sitter 3-brane into a five-dimensional bulk is
studied, assuming a scalar field with potential is present in the bulk. A class
of solutions is found in closed form that can represent a thick de Sitter
3-brane interpolating either between two dynamical black holes with a topology or between two Rindler-like spacetimes with a topology. The gravitational field is localized in a small region near
the center of the 3-brane. The analysis of graviton fluctuations shows that a
zero mode exists and separates itself from a set of continuous modes by a mass
gap. The existence of such a mass gap is shown to be universal. The scalar
perturbations are also studied and shown to be stable.Comment: the study of scalar perturbations and some relevant references have
been added. The most used definition for mass in de Sitter space has been
adopte
Autologous bone marrow expanded mesenchymal stem cells in patellar tendinopathy: protocol for a phase I/II, single-centre, randomized with active control PRP, double-blinded clinical trial
Introduction: Patellar tendon overuse injuries are common in athletes. Imaging may show a change in tissue
structure with tendon thickening and disruption of the intratendinous substance. We wish to test the hypothesis
that both autologous bone marrow expanded mesenchymal stem cells and autologous leukocyte-poor platelet-rich
plasma (LP-PRP) implanted into the area of the disrupted tendinopathic patellar tendon will restore function, but
tendon regeneration tissue will only be observed in the subjects treated with autologous bone marrow expanded
mesenchymal stem cells.
Methods and analysis: This is a single-centre, pilot phase I/II, double-blinded clinical trial with randomisation with
active control. Twenty patients with a diagnosis of patellar tendinopathy with imaging changes (tendon thickening
and disruption of the intratendinous substance at the proximal portion of the patellar tendon) will be randomised
in a 1:1 ratio to receive a local injection of either bone-marrow autologous mesenchymal stem cells (MSC), isolated
and cultured under GMP at The Institute of Biology and Molecular Genetics (IBGM) (Spain) or P-PRP. The study will
have two aims: first, to ascertain whether a clinically relevant improvement after 3, 6 and 12 months according to
the visual analogue scale (VAS), Victorian Institute of Sport Assessment for patellar tendons (VISA-P) and
dynamometry scales (DYN) will be achieved; and second, to ascertain whether the proposed intervention will
restore tendon structure as determined by ultrasonography (US), Doppler ultrasonography (DUS), and innovative
MRI and ultrasound techniques: Magnetic Resonance T2 FAT SAT (UTE, Ultrashort Echo TE) sequence and
Ultrasound Tissue Characterization (UTC). Patients who are randomised to the P-PRP treatment group but do not
achieve a satisfactory primary endpoint after 6 months will be offered treatment with MSC
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