1,671 research outputs found

    Instability of black hole formation under small pressure perturbations

    Get PDF
    We investigate here the spectrum of gravitational collapse endstates when arbitrarily small perfect fluid pressures are introduced in the classic black hole formation scenario as described by Oppenheimer, Snyder and Datt (OSD) [1]. This extends a previous result on tangential pressures [2] to the more physically realistic scenario of perfect fluid collapse. The existence of classes of pressure perturbations is shown explicitly, which has the property that injecting any smallest pressure changes the final fate of the dynamical collapse from a black hole to a naked singularity. It is therefore seen that any smallest neighborhood of the OSD model, in the space of initial data, contains collapse evolutions that go to a naked singularity outcome. This gives an intriguing insight on the nature of naked singularity formation in gravitational collapse.Comment: 7 pages, 1 figure, several modifications to match published version on GR

    Idiopathic Infantile arterial calcification –A Very rare case

    Get PDF
    A rare case of Idiopathic Arterial Calcification of Infancy (IACI), inherited as an autosomal recessive disease, is reported

    Development and Targeting Efficiency of Irinotecan Engineered Proniosomes

    Get PDF
    Purpose: This study is aimed at achieving improvement in the efficacy, reduced toxicity and enhancement of therapeutic index of irinotecan.Methods: Proniosomes of irinotecan hydrochloride trihydrate were prepared by slurry method using different surfactants, cholesterol and dicetyl phosphate. The formulations were then characterized with respect to shape, surface morphology, entrapment efficiency, in vitro drug release, in vivo drug targeting and stability.Results: The proniosomes were smooth in texture indicating, thin and uniform coating over maltodextrin powder. The highest entrapment efficiency was found for formulation F2 (74.9 ± 2.7 %). The highest cumulative drug release in 24 h was achieved with formulation F3 (98.2 %) In vivo results for the proniosomes reveal that the drug was preferentially targeted to liver followed by lung and spleen. Stability studies indicate that 4 ºC was the most suitable condition for the storage of formulation F2.Conclusion: Proniosomes offer a suitable alternative colloidal carrier approach to achieving drug targeting. Proniosomes containing irinotecan are retained at targeted sites and are capable of releasing drug for an extended period of time.Keywords: Irinotecan, proniosomes, Drug targeting, In vivo tissue distribution, Stability studies

    Severe Sub-Acromial Bursitis with Rice Bodies in a Patient with Rheumatoid Arthritis: A Case Report and Review of Literature

    Get PDF
    Multiple rice body formation is a rare presentation of chronic sub-acromial bursitis secondary to extensive underlying rheumatoid arthritis, sero-negative inflammatory arthritis or tuberculous joints. Although there is usually an accompanying inflammatory arthropathy, it can occur in the absence of any underlying systemic disorder. We report a case of five years old neglected rice body deposition in shoulder in a 54-years old lady diagnosed to be having rheumatoid arthritis. After initial investigations, arthroscopic removal of rice bodies with bursa excision relieved the symptoms. The underlying rheumatic condition continued its course, generally sparing the involved shoulder joint. We suggest thorough examination for systemic rheumatologic disease in patients diagnosed with such lesions

    General Minimal Flavor Violation

    Get PDF
    A model independent study of the minimal flavor violation (MFV) framework is presented, where the only sources of flavor breaking at low energy are the up and down Yukawa matrices. Two limits are identified for the Yukawa coupling expansion: linear MFV, where it is truncated at the leading terms, and nonlinear MFV, where such a truncation is not possible due to large third generation Yukawa couplings. These are then resummed to all orders using non-linear sigma-model techniques familiar from models of collective breaking. Generically, flavor diagonal CP violating (CPV) sources in the UV can induce O(1) CPV in processes involving third generation quarks. Due to a residual U(2) symmetry, the extra CPV in B_d-\bar B_d mixing is bounded by CPV in B_s-\bar B_s mixing. If operators with right-handed light quarks are subdominant, the extra CPV is equal in the two systems, and is negligible in processes involving only the first two generations. We find large enhancements in the up type sector, both in CPV in D-\bar D mixing and in top flavor violation.Comment: 5 pages and no figure

    Histone Deacetylase Inhibitors Prevent Pulmonary Endothelial Hyperpermeability and Acute Lung Injury By Regulating Heat Shock Protein 90 Function

    Get PDF
    Transendothelial hyperpermeability caused by numerous agonists is dependent on heat shock protein 90 (Hsp90) and leads to endothelial barrier dysfunction (EBD). Inhibition of Hsp90 protects and restores transendothelial permeability. Hyperacetylation of Hsp90, as by inhibitors of histone deacetylase (HDAC), suppresses its chaperone function and mimics the effects of Hsp90 inhibitors. In this study we assessed the role of HDAC in mediating lipopolysaccharide (LPS)-induced transendothelial hyperpermeability and acute lung injury (ALI). We demonstrate that HDAC inhibition protects against LPS-mediated EBD. Inhibition of multiple HDAC by the general inhibitors panobinostat or trichostatin provided protection against LPS-induced transendothelial hyperpermeability, acetylated and suppressed Hsp90 chaperone function, and attenuated RhoA activity and signaling crucial to endothelial barrier function. Treatment with the HDAC3-selective inhibitor RGFP-966 or the HDAC6-selective inhibitor tubastatin A provided partial protection against LPS-mediated transendothelial hyperpermeability. Similarly, knock down of HDAC3 and HDAC6 by specific small-interfering RNAs provided significant protection against LPS-induced EBD. Furthermore, combined pharmacological inhibition of both HDAC3 and -6 attenuated the inflammation, capillary permeability, and structural abnormalities associated with LPS-induced ALI in mice. Together these data indicate that HDAC mediate increased transendothelial hyperpermeability caused by LPS and that inhibition of HDAC protects against LPS-mediated EBD and ALI by suppressing Hsp90-dependent RhoA activity and signaling

    Gravitational collapse with tachyon field and barotropic fluid

    Full text link
    A particular class of space-time, with a tachyon field, \phi, and a barotropic fluid constituting the matter content, is considered herein as a model for gravitational collapse. For simplicity, the tachyon potential is assumed to be of inverse square form i.e., V(\phi) \sim \phi^{-2}. Our purpose, by making use of the specific kinematical features of the tachyon, which are rather different from a standard scalar field, is to establish the several types of asymptotic behavior that our matter content induces. Employing a dynamical system analysis, complemented by a thorough numerical study, we find classical solutions corresponding to a naked singularity or a black hole formation. In particular, there is a subset where the fluid and tachyon participate in an interesting tracking behaviour, depending sensitively on the initial conditions for the energy densities of the tachyon field and barotropic fluid. Two other classes of solutions are present, corresponding respectively, to either a tachyon or a barotropic fluid regime. Which of these emerges as dominant, will depend on the choice of the barotropic parameter, \gamma. Furthermore, these collapsing scenarios both have as final state the formation of a black hole.Comment: 18 pages, 7 figures. v3: minor changes. Final version to appear in GR

    Human and Canine Echinococcosis Infection in Informal, Unlicensed Abattoirs in Lima, Peru

    Get PDF
    Echinococcus granulosus infections are a major public health problem in livestock-raising regions around the world. The life cycle of this tapeworm is sustained between dogs (definitive host, canine echinococcosis), and herbivores (intermediary host, cystic hydatid disease). Humans may also develop cystic hydatid disease. Echinococcosis is endemic in rural areas of Peru; nevertheless, its presence or the extension of the problem in urban areas is basically unknown. Migration into Lima, an 8-million habitant's metropolis, creates peripheral areas where animals brought from endemic areas are slaughtered without veterinary supervision. We identified eight informal, unlicensed abattoirs in a peripheral district of Lima and performed a cross-sectional study in to assess the prevalence of canine echinococcosis, evaluated by coproELISA followed by PCR evaluation and arecoline purge. Eight of 22 dogs (36%) were positive to coproELISA, and four (18%) were confirmed to be infected with E. granulosus tapeworms either by PCR or direct observation (purge). Later evaluation of the human population living in these abattoirs using abdominal ultrasound, chest X-rays and serology, found 3 out of 32 (9.3%) subjects with echinococcal cysts in the liver (two viable, one calcified), one of whom had also lung involvement and a strongly positive antibody response. Autochthonous transmission of E. granulosus is present in Lima. Informal, unlicensed abattoirs may be sources of infection to neighbouring people in this urban environment

    Scalar-field Pressure in Induced Gravity with Higgs Potential and Dark Matter

    Full text link
    A model of induced gravity with a Higgs potential is investigated in detail in view of the pressure components related to the scalar-field excitations. The physical consequences emerging as an artifact due to the presence of these pressure terms are analysed in terms of the constraints parting from energy density, solar-relativistic effects and galactic dynamics along with the dark matter halos.Comment: 26 pages, 3 figures, Minor revision, Published in JHE
    corecore