131 research outputs found

    Hidden Degeneracy in the Brick Wall Model of Black Holes

    Get PDF
    Quantum field theory in the near-horizon region of a black hole predicts the existence of an infinite number of degenerate modes. Such a degeneracy is regulated in the brick wall model by the introduction of a short distance cutoff. In this Letter we show that states of the brick wall model with non zero energy admit a further degeneracy for any given finite value of the cutoff. The black hole entropy is calculated within the brick wall model taking this degeneracy into account. Modes with complex frequencies however do not exhibit such a degeneracy.Comment: 8 pages, Latex fil

    Protein carbonyls and protein thiols in rheumatoid arthritis

    Get PDF
    Background: Oxidative stress (OS) has an important role in the pathogenesis and progression of rheumatoid arthritis (RA). OS causes protein modification, thereby impairing the biological functions of the protein. This study was conducted to assess the oxidatively modified protein as protein carbonyl content and the antioxidant status as protein thiols, and to study the association between protein carbonyls and protein thiols in RA.Methods: Newly diagnosed RA patients who were not taking any disease modifying anti-rheumatic drugs were included into the study group (n=45) along with age and sex matched healthy controls (n=45). Serum protein carbonyl content and protein thiols were estimated.Results: Elevated protein carbonyl content and decreased protein thiol levels (p<0.001) were observed in RA. A significant negative correlation was observed between protein carbonyl content and protein thiol levels (p<0.001).Conclusions: Oxidative stress in RA is evidenced by enhanced protein oxidation and decreased antioxidant protein thiol levels. Decreased protein thiols may also reflect protein modifications leading to compromise in the antioxidant properties. This oxidant and antioxidant imbalance needs to be addressed by therapeutic interventions to prevent disease progression

    Inside the plant: Bacterial endophytes and abiotic stress alleviation

    Get PDF
    Bacterial endophytes are the microbes internally associated with the plant, nourished in an isolated environment which is free from the external harsh and changeable ecological condition. They entered into the plant tissues and alleviate the biotic and abiotic stresses by producing numerous secondary metabolites. They are engaged with the de novo synthesis of structural compounds and stimulation of plant immunity. They are also involved in the process of exclusion of the pathogen by niche competition and actively take part in phenylpropanoid metabolism. Abiotic stresses in particular salinity problem, low pH, heavy metal toxicity and accumulation of recalcitrant complex compounds in the soil affecting the plant health are a major threat to the agriculture sector in crop production and stability of ecosystems. To cope with these problems agriculture productivity has been intensified by using synthetic chemicals and pesticides causes numerous problems worldwide. Endophytic bacteria are thus being utilized as a substitute to reduce the use of toxic chemicals and pesticides. They may be employed as a biological agent in the plant growth promotion and for the management of the global environment. There is a tremendous scope for the isolation and identification of new endophytic bacteria with excellent potential

    Bound States in Gapped Graphene with Impurities : Effective Low-Energy Description of Short-Range Interactions

    Full text link
    We obtain a novel bound state spectrum of the low energy excitations near the Fermi points of graphene in the presence of a charge impurity. The effects of possible short range interactions induced by the impurity are modelled by suitable boundary conditions. The spectrum in the subcritical region of the effective Coulomb coupling is labelled by a parameter which characterizes the boundary conditions and determines the inequivalent quantizations of the system. In the supercritical region we obtain a renormalization group flow for the effective Coulomb coupling.Comment: 8 pages, 1 figure, Latex file, minor changes in the text, title changed in the journa

    Tissue biomarkers in prognostication of serous ovarian cancer following neoadjuvant chemotherapy

    Get PDF
    Serous ovarian cancer (SOC) is a significant cause of morbidity and mortality in females with poor prognosis because of advanced stage at presentation. Recently, neoadjuvant chemotherapy (NACT) is being used for management of advanced SOC, but role of tissue biomarkers in prognostication following NACT is not well established. The study was conducted on advanced stage SOC patients (n = 100) that were treated either conventionally (n = 50) or with NACT (n = 50), followed by surgery. In order to evaluate the expression of tissue biomarkers (p53, MIB1, estrogen and progesterone receptors, Her-2/neu, E-cadherin, and Bcl2), immunohistochemistry and semiquantitative scoring were done following morphological examination. Following NACT, significant differences in tumor histomorphology were observed as compared to the native neoplasms. MIB 1 was significantly lower in cases treated with NACT and survival outcome was significantly better in cases with low MIB 1. ER expression was associated with poor overall survival. No other marker displayed any significant difference in expression or correlation with survival between the two groups. Immunophenotype of SOC does not differ significantly in samples from cases treated with NACT, compared to upfront surgically treated cases. The proliferating capacity of the residual tumor cells is less, depicted by low mean MIB1 LI. MIB 1 and ER inversely correlate with survival

    Supercilliary madarosis in an Indian male with Chronic Myelogenous Leukemia Treated with Dasatinib - A case report

    Get PDF
    Dasatinib, a second generation multi-target tyrosine kinase inhibitor (TKI) is active against many imatinib-resistant BCR-ABL mutant forms, Src, and c-Kit tyrosine kinases. While skin hypopigmentation is a well recognized adverse effect of first generation TKIs; it has rarely been reported with dasatinib. We report a rare case of diffuse cutaneous hypopigmentation and bilateral supercilliary madarosis induced by dasatinib. A 51 year-old Indian male with no co-morbidities and with history of chronic myelogenous leukaemia with complex variant of Philadelphia translocation and E 225 V mutation in P loop domain of bcr-abl transcript who was initiated on imatinib followed by dasatinib as a part of treatment. After 5 months of treatment with dasatinib, he developed supercilliary madarosis bilaterally. Cutaneous side effects may adversely affect patient’s quality of life and, therefore, require prompt attention to prevent long-term complications or suboptimal outcomes due to poor compliance

    Geometric Finiteness, Holography and Quasinormal Modes for the Warped AdS_3 Black Hole

    Full text link
    We show that there exists a precise kinematical notion of holography for the Euclidean warped AdS3AdS_3 black hole. This follows from the fact that the Euclidean warped AdS3AdS_3 black hole spacetime is a geometrically finite hyperbolic manifold. For such manifolds a theorem of Sullivan provides a one-to-one correspondence between the hyperbolic structure in the bulk and the conformal structure of its boundary. Using this theorem we obtain the holographic quasinormal modes for the warped AdS3AdS_3 black hole.Comment: Latex file, 7 pages. Journal versio

    Effect of topological defects and Coulomb charge on the low energy quantum dynamics of gapped graphene

    Full text link
    We study the combined effect of a conical topological defect and a Coulomb charge impurity on the dynamics of Dirac fermions in gapped graphene. Beyond a certain strength of the Coulomb charge, quantum instability sets in, which demarcates the boundary between sub and supercritical values of the charge. In the subcritical regime, for certain values of the system parameters, the allowed boundary conditions in gapped graphene cone can be classified in terms of a single real parameter. We show that the observables such as local density of states, scattering phase shifts and the bound state spectra are sensitive to the value of this real parameter, which is interesting from an empirical point of view. For a supercritical Coulomb charge, we analyze the system with a regularized potential as well as with a zigzag boundary condition and find the effect of the sample topology on the observable features of the system.Comment: 22 pages, 23 figure

    Evaluation of phenolics, capsaicinoids, antioxidant properties, and major macro-micro minerals of some hot and sweet peppers and ginger land-races of Malaysia

    Get PDF
    There are compelling evidences that oxidative stress plays important role in age‐related neurodegenerative diseases and natural food‐derived dietary antioxidants appear to be the first line of defence to take care of the oxidative stress. The analysis results of this study showed that Cili Burung of the hot pepper landraces contained the highest amount of TPC (1.00 mg/g DW), TFC (0.17 mg/g DW), capsaicinoids (0.05 mg/g), and the highest FRAP activity (439 mg/g DW). However, DPPH assay revealed the highest DPPH scavenging activity (IC50 = 250 μg/ml) in Halia Bara rhizome. Rhizomes of both landraces of ginger showed a significant amount of capsaicinoids. Hot pepper Cili Ungu (5.50 g/kg) and sweet pepper Cili Kulai had the highest P contents (~5.5 g/kg). Halia Bentong ginger rhizome had the highest content of K (33.84 g/kg); however, Halia Bentong ginger roots had remarkably greater contents of Ca (10.96 g/kg). Ginger rhizomes and roots had greater contents of micro minerals compared to hot and sweet chili peppers. Ginger roots contained good amounts of bioactive compounds and mineral nutrients indicating its commercial value
    corecore