648 research outputs found
Gene Expression Profiles as Markers of Aggressive Disease-EGFR as a Factor
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
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
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
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
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 in ion-ion collisions
We study the threshold -meson production in the process , 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 . We predict the
ratio of cross sections for meson production in - and -collisions and the polarization properties of the -meson, in
, as a function of a single parameter, which
characterizes the relative role of transversal and longitudinal -meson
polarizations in the process .Comment: 10 pages 3 figure
Lack of uniform diagnostic criteria for cervical radiculopathy in conservative intervention studies: A systematic review
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
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
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 He-B: fermion zero modes on interfaces and in the vortex core
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 He-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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