648 research outputs found

    Gene Expression Profiles as Markers of Aggressive Disease-EGFR as a Factor

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    We previously reported that 43 (58%) of 75 head and neck squamous cell carcinoma (HNSCC) tumors harbor increased epidermal growth factor receptor (EGFR) gene copy numbers as determined by fluorescent in situ hybridization. In this study, an increased EGFR copy number was associated with decreased progression-free survival and overall survival of HNSCC patients. However, activated EGFR protein levels are difficult to quantify by immunohistochemistry and are subject to dynamic regulation, specifically receptor downregulation on ligand binding. Therefore, we generated an activated EGFR gene expression signature in an in vitro HaCaT keratinocyte model system to further study genes involved in the EGFR signaling pathway in HNSCC. The results from this model system have suggested that the activated EGFR signature might reflect the activated state of the EGFR pathway in human HNSCC tumors and that it is associated with the increased EGFR gene copy number by fluorescent in situ hybridization. Furthermore, the activated EGFR signature has provided additional leads, because they are related to co-regulated molecular pathways and associated gene products on activation of EGFR. These could be exploited to refine and optimize combination therapies to be used in conjunction with available EGFR inhibitors in individual HNSCC patients

    Special relativity constraints on the effective constituent theory of hybrids

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    We consider a simplified constituent model for relativistic strong-interaction decays of hybrid mesons. The model is constructed using rules of renormalization group procedure for effective particles in light-front quantum field theory, which enables us to introduce low-energy phenomenological parameters. Boost covariance is kinematical and special relativity constraints are reduced to the requirements of rotational symmetry. For a hybrid meson decaying into two mesons through dissociation of a constituent gluon into a quark-anti-quark pair, the simplified constituent model leads to a rotationally symmetric decay amplitude if the hybrid meson state is made of a constituent gluon and a quark-anti-quark pair of size several times smaller than the distance between the gluon and the pair, as if the pair originated from one gluon in a gluonium state in the same effective theory.Comment: 11 pages, 5 figure

    Remarks on the Causality, Unitarity and Supersymmetric Extension of the Lorentz and CPT-Violating Maxwell-Chern-Simons Model

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    The gauge-invariant Chern-Simons-type Lorentz- and CPT-breaking term is here re-assessed and issues like causality, unitarity, spontaneous gauge-symmetry breaking are investigated. Moreover, we obtain a minimal extension of such a system to a supersymmetric environment. We comment on resulting peculiar self-couplings for the gauge sector, as well as on background contribution for gaugino masses.Comment: 5 pages, NPB style, talk presented at "Renormalization Group and Anomalies in Gravity and Cosmology", Ouro Preto, Brazil, March 200

    Dual embedding of the Lorentz-violating electrodinamics and Batalin-Vilkovisky quantization

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    Modifications of the electromagnetic Maxwell Lagrangian in four dimensions have been considered by some authors. One may include an explicit massive term (Proca) and a topological but not Lorentz-invariant term within certain observational limits. We find the dual-corresponding gauge invariant version of this theory by using the recently suggested gauge embedding method. We enforce this dualisation procedure by showing that, in many cases, this is actually a constructive method to find a sort of parent action, which manifestly establishes duality. We also use the gauge invariant version of this theory to formulate a Batalin-Vilkovisky quantization and present a detailed discussion on the excitation spectrum.Comment: 8 page

    Deuteron Electromagnetic Form Factors in the Intermediate Energy Region

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    Based on a Perturbative QCD analysis of the deuteron form factor, a model for the reduced form factor is suggested. The numerical result is consistent with the data in the intermediate energy region.Comment: 9 pages, to appear in Phys.Rev.

    The reaction Δ+NN+N+ϕ\Delta+N\to N+N+\phi in ion-ion collisions

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    We study the threshold ϕ\phi-meson production in the process Δ+NN+N+ϕ\Delta+N\to N+N+\phi, which appears as a possible important mechanism in high energy nuclei-nuclei collisions. The isotopic invariance of the strong interaction and the selection rules due to P-parity and total angular momentum result in a general and model independent parametrization of the spin structure of the matrix element in terms of three partial amplitudes. In the framework of one-pion exchange model these amplitudes can be derived in terms of the two threshold partial amplitudes for the process π+NN+ϕ\pi+N\to N+\phi. We predict the ratio of cross sections for ϕ\phi-meson production in pppp- and ΔN\Delta N-collisions and the polarization properties of the ϕ\phi-meson, in Δ+NN+N+ϕ\Delta+N\to N+N+\phi, as a function of a single parameter, which characterizes the relative role of transversal and longitudinal ϕ\phi-meson polarizations in the process π+NN+ϕ\pi+N\to N+\phi.Comment: 10 pages 3 figure

    Lack of uniform diagnostic criteria for cervical radiculopathy in conservative intervention studies: A systematic review

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    Purpose: Cervical radiculopathy (CR) is a common diagnosis. It is unclear if intervention studies use uniform definitions and criteria for patient selection. Our objective was to assess the uniformity of diagnostic criteria and definitions used in intervention studies to select patients with CR. Methods: We electronically searched the Cochrane Controlled Trials Register, MEDLINE, EMBASE and CINAHL. Studies were included when evaluating conservative interventions in randomised clinical trials (RCTs) in patients with CR. Selection criteria and definitions for patients with CR were extracted and evaluated on their uniformity. Results: Thirteen RCTs were included. Pain was used as an inclusion criterion in 11 studies. Inclusion based on the duration and location of pain varied between studies. Five studies used sensory symptoms in the arm as inclusion crite

    Supersymmetric Extension of the Lorentz and CPT-Violating Maxwell-Chern-Simons Model

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    Focusing on gauge degrees of freedom specified by a 1+3 dimensions model hosting a Maxwell term plus a Lorentz and CPT non-invariant Chern-Simons-like contribution, we obtain a minimal extension of such a system to a supersymmetric environment. We comment on resulting peculiar self-couplings for the gauge sector, as well as on background contribution for gaugino masses. Furthermore, a non-polynomial generalization is presented.Comment: revtex4, 4 pages, no figure

    Presence of a Distinct S3 Layer in Mild Compression Wood Tracheids of Pinus radiata

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    A study of electron microscopic evidence for the presence of a distinct S3 layer in mild compression wood tracheids of Pinus radiata was performed. S3 layers have an important role to play in strengthening the xylem tissues in standing trees and in minimizing collapse in wood tissues. These layers are also likely to be an important factor in wood processes involving physical and chemical treatments, as well as in the biodegradation of wood

    Topological superfluid 3^3He-B: fermion zero modes on interfaces and in the vortex core

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    Many quantum condensed matter systems are strongly correlated and strongly interacting fermionic systems, which cannot be treated perturbatively. However, topology allows us to determine generic features of their fermionic spectrum, which are robust to perturbation and interaction. We discuss the nodeless 3D system, such as superfluid 3^3He-B, vacuum of Dirac fermions, and relativistic singlet and triplet supercondutors which may arise in quark matter. The systems, which have nonzero value of topological invariant, have gapless fermions on the boundary and in the core of quantized vortices. We discuss the index theorem which relates fermion zero modes on vortices with the topological invariants in combined momentum and coordinate space.Comment: paper is prepared for Proceedings of the Workshop on Vortices, Superfluid Dynamics, and Quantum Turbulence held on 11-16 April 2010, Lammi, Finlan
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