256 research outputs found

    A COMPARATIVE EVALUATION OF ENZYMATIC ANTIOXIDANT LEVELS IN PRE AND POST THERAPY PATIENTS WITH ORAL CANCER

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    Objectives: The present study was aimed to evaluate the magnitude of oxidative stress and levels of enzymatic antioxidants in Oral Squamous cell carcinoma (OSCC) patients receiving radiotherapy (RT) and chemo radiotherapy (CRT). Venous blood samples were collected from 20 healthy subjects, 20 disease control patients (without treatment), 20 oral cancer patients who received chemo radiotherapy and 20 oral cancer patients receiving radiotherapy and were analyzed for antioxidant status using various assay techniques. Methods: The present study measured the levels of three antioxidants enzymes: Superoxide dismutase (SOD), Glutathione Peroxidase (GPX), Catalase (CAT) in the plasma samples of 20 patients who were proven with biopsy-Squamous cell carcinoma of the oral cancer with clinical stage III/IV and were receiving radio and chemo radiotherapy. Same enzymes were also estimated in 20 healthy individuals and disease control patients (who were admitted in to the cancer clinic). Results: The plasma levels of antioxidant enzymes (SOD, CAT, and GPX) were lower in the oral cancer patients as compared to those in the healthy individuals. Superoxide dismutase levels in healthy control patients were found to be 190.4µg/dl, 34.54 µg/dl in disease control patients, 46.16 µg/dl in radiotherapy received group patients and 81.48 µg/dl in chemo and radiotherapy received group patients. Glutathione peroxidase levels were found to be 65.713 µg/dl in healthy control group patients, 13.8 µg/dl in disease control patients, 16.49 µg/dl in radiotherapy received group patients, 34.2 µg/dl in chemo and radiotherapy received group patients. Catalase enzyme levels were found to be 52.37 µg/dl in healthy control group patients, 12.35 µg/dl in disease control group patients, 22.34 µg/dl in radiotherapy received group patients, 27.18 µg/dl inchemo and radiotherapy received group patients. These enzymes also showed significant changes with radiotherapy and chemoradiotherapy. Antioxidant enzymes in the plasma of the oral cancer patients after radiation therapy lowered as compared to the plasma levels of enzymes after chemoradiotherapy. Conclusion: This present study also showed decreased levels of antioxidant enzymes in the plasma of the oral cavity cancer patients after radiation therapy as compared to the chemoradiotherapy receiving oral cancer patients. An appreciable progress in antioxidant levels were observed in patients after receiving chemoradiotherapy (CRT) and observed to be more effective than after radiotherapy (RT). The reason for this observation was believed that concomitant chemoradiation and radiotherapy caused a reduction in the lipid peroxidation process and an improvement in the antioxidant levels of the oral cancer patients. But the radiation therapy produces high oxidative stress when compared to chemoradiotherapy in Oral Squamous Cell Carcinoma

    Ni/H-ZSM-5 as a stable and promising catalyst for COx free H2 production by CH4 decomposition

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    Catalytic decomposition of methane for COx free hydrogen production is carried out over Ni supported on H-ZSM-5 catalysts with different Si/Al ratios (i.e. 40, 150, 300 and 485) at 550 °C and atmospheric pressure. Methane decomposition activity of Ni/H-ZSM-5 is decreased with time on stream and finally deactivated completely. The fresh and reduced catalysts are characterized by BET-SA, XRD, FT-IR, UV-DRS, TPR, pulse chemisorption of H2 and N2O and some of the used catalysts are characterised by CHNS, SEM, TEM and Raman spectroscopy. Raman spectra of the used catalysts showed both ordered and disordered carbon at 1580 cm-1 and 1320 cm-1. The 20 wt% Ni/H-ZSM-5 (Si/Al = 150) exhibited a higher H2 production rate over the other Ni loadings. The superior performance of 20 wt% Ni/H-ZSM-5 (Si/Al = 150) is rationalized by the physico-chemical properties of the various Ni loaded H-ZSM-5 catalysts

    A QUERY ON PUBMED RESULTS USING HIERARCHIES

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    ABSTRACT: A natural way to organize biomedical citations is according to their MeSH annotations. MeSH is a comprehensive concept hierarchy used by PubMed. In this paper, we present the BioNav system, a novel search interface that enables the user to navigate large number of query results by organizing them using the MeSH concept hierarchy. First, the query results are organized into a navigation tree. At each node expansion step, BioNav reveals only a small subset of the concept nodes, selected such that the expected user navigation cost is minimized. In contrast, previous works expand the hierarchy in a predefined static manner, without navigation cost modeling. INTRODUCTION

    Interpreting a 1 fb^-1 ATLAS Search in the Minimal Anomaly Mediated Supersymmetry Breaking Model

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    Recent LHC data significantly extend the exclusion limits for supersymmetric particles, particularly in the jets plus missing transverse momentum channels. The most recent such data have so far been interpreted by the experiment in only two different supersymmetry breaking models: the constrained minimal supersymmetric standard model (CMSSM) and a simplified model with only squarks and gluinos and massless neutralinos. We compare kinematical distributions of supersymmetric signal events predicted by the CMSSM and anomaly mediated supersymmetry breaking (mAMSB) before calculating exclusion limits in mAMSB. We obtain a lower limit of 900 GeV on squark and gluino masses at the 95% confidence level for the equal mass limit, tan(beta)=10 and mu>0.Comment: 18 pages, 11 figure

    New perturbation theory representation of the conformal symmetry breaking effects in gauge quantum field theory models

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    We propose a hypothesis on the detailed structure for the representation of the conformal symmetry breaking term in the basic Crewther relation generalized in the perturbation theory framework in QCD renormalized in the MSˉ{\rm \bar{MS}} scheme. We establish the validity of this representation in the O(αs4)O(\alpha_s^4) approximation. Using the variant of the generalized Crewther relation formulated here allows finding relations between specific contributions to the QCD perturbation series coefficients for the flavor nonsinglet part of the Adler function DAnsD^{ns}_A for the electron-positron annihilation in hadrons and to the perturbation series coefficients for the Bjorken sum rule SBjpS_\text{Bjp} for the polarized deep-inelastic lepton-nucleon scattering. We find new relations between the αs4\alpha_s^4 coefficients of DAnsD^{ns}_A and SBjpS_\text{Bjp}. Satisfaction of one of them serves as an additional theoretical verification of the recent computer analytic calculations of the terms of order αs4\alpha_s^4 in the expressions for these two quantities.Comment: 12 pages, Title modified, abstract modified, improved and extended variant of the talks, presented at Int. Seminar "Quarks-2010" (6-12 June, 2010, Kolomna) and Int. Workshop Hadron Structure and QCD: From Low to High Energies (5-9 July 2010, Gatchina

    Distinguishing Various Models of the 125 GeV Boson in Vector Boson Fusion

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    The hint of a new particle around 125 GeV at the LHC through the decay modes of diphoton and a number of others may point to quite a number of possibilities. While at the LHC the dominant production mechanism for the Higgs boson of the standard model and some other extensions is via the gluon fusion process, the alternative vector boson fusion is more sensitive to electroweak symmetry breaking through the gauge-Higgs couplings and therefore can be used to probe for models beyond the standard model. In this work, using the well known dijet-tagging technique to single out the vector boson fusion mechanism, we investigate its capability to discriminate a number of models that have been suggested to give an enhanced inclusive diphoton production rate, including the standard model Higgs boson, fermiophobic Higgs boson, Randall-Sundrum radion, inert-Higgs-doublet model, two-Higgs-doublet model, and the MSSM. The rates in vector-boson fusion can give more information of the underlying models to help distinguishing among the models.Comment: 31 pages, 3 figures; in this version some wordings are change

    Higgs decay to dark matter in low energy SUSY: is it detectable at the LHC ?

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    Due to the limited statistics so far accumulated in the Higgs boson search at the LHC, the Higgs boson property has not yet been tightly constrained and it is still allowed for the Higgs boson to decay invisibly to dark matter with a sizable branching ratio. In this work, we examine the Higgs decay to neutralino dark matter in low energy SUSY by considering three different models: the minimal supersymmetric standard model (MSSM), the next-to-minimal supersymmetric standard models (NMSSM) and the nearly minimal supersymmetric standard model (nMSSM). Under current experimental constraints at 2-sigma level (including the muon g-2 and the dark matter relic density), we scan over the parameter space of each model. Then in the allowed parameter space we calculate the branching ratio of the SM-like Higgs decay to neutralino dark matter and examine its observability at the LHC by considering three production channels: the weak boson fusion VV->h, the associated production with a Z-boson pp->hZ+X or a pair of top quarks pp->htt_bar+X. We find that in the MSSM such a decay is far below the detectable level; while in both the NMSSM and nMSSM the decay branching ratio can be large enough to be observable at the LHC.Comment: Version in JHE

    Exploring the Higgs Portal with 10/fb at the LHC

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    We consider the impact of new exotic colored and/or charged matter interacting through the Higgs portal on Standard Model Higgs boson searches at the LHC. Such Higgs portal couplings can induce shifts in the effective Higgs-gluon-gluon and Higgs-photon-photon couplings, thus modifying the Higgs production and decay patterns. We consider two possible interpretations of the current LHC Higgs searches based on ~ 5/fb of data at each detector: 1) a Higgs boson in the mass range (124-126) GeV and 2) a `hidden' heavy Higgs boson which is underproduced due to the suppression of its gluon fusion production cross section. We first perform a model independent analysis of the allowed sizes of such shifts in light of the current LHC data. As a class of possible candidates for new physics which gives rise to such shifts, we investigate the effects of new scalar multiplets charged under the Standard Model gauge symmetries. We determine the scalar parameter space that is allowed by current LHC Higgs searches, and compare with complementary LHC searches that are sensitive to the direct production of colored scalar states.Comment: 27 pages, 11 figures; v2: references added, correction to scalar form factor, numerical results updated with Moriond 2012 data, conclusions unchange

    R-parity Conservation via the Stueckelberg Mechanism: LHC and Dark Matter Signals

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    We investigate the connection between the conservation of R-parity in supersymmetry and the Stueckelberg mechanism for the mass generation of the B-L vector gauge boson. It is shown that with universal boundary conditions for soft terms of sfermions in each family at the high scale and with the Stueckelberg mechanism for generating mass for the B-L gauge boson present in the theory, electric charge conservation guarantees the conservation of R-parity in the minimal B-L extended supersymmetric standard model. We also discuss non-minimal extensions. This includes extensions where the gauge symmetries arise with an additional U(1)_{B-L} x U(1)_X, where U(1)_X is a hidden sector gauge group. In this case the presence of the additional U(1)_X allows for a Z' gauge boson mass with B-L interactions to lie in the sub-TeV region overcoming the multi-TeV LEP constraints. The possible tests of the models at colliders and in dark matter experiments are analyzed including signals of a low mass Z' resonance and the production of spin zero bosons and their decays into two photons. In this model two types of dark matter candidates emerge which are Majorana and Dirac particles. Predictions are made for a possible simultaneous observation of new physics events in dark matter experiments and at the LHC.Comment: 38 pages, 7 fig

    Where is SUSY?

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    The direct searches for Superymmetry at colliders can be complemented by direct searches for dark matter (DM) in underground experiments, if one assumes the Lightest Supersymmetric Particle (LSP) provides the dark matter of the universe. It will be shown that within the Constrained minimal Supersymmetric Model (CMSSM) the direct searches for DM are complementary to direct LHC searches for SUSY and Higgs particles using analytical formulae. A combined excluded region from LHC, WMAP and XENON100 will be provided, showing that within the CMSSM gluinos below 1 TeV and LSP masses below 160 GeV are excluded (m_{1/2} > 400 GeV) independent of the squark masses.Comment: 16 pages, 10 figure
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