260 research outputs found
A COMPARATIVE EVALUATION OF ENZYMATIC ANTIOXIDANT LEVELS IN PRE AND POST THERAPY PATIENTS WITH ORAL CANCER
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
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
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
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
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 scheme. We establish the validity of this representation in the
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 for the electron-positron
annihilation in hadrons and to the perturbation series coefficients for the
Bjorken sum rule for the polarized deep-inelastic lepton-nucleon
scattering. We find new relations between the coefficients of
and . Satisfaction of one of them serves as an
additional theoretical verification of the recent computer analytic
calculations of the terms of order 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
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 ?
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
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
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?
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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