173 research outputs found
A VELOUR post hoc subset analysis: prognostic groups and treatment outcomes in patients with metastatic colorectal cancer treated with aflibercept and FOLFIRI
The VELOUR study demonstrated a survival benefit for FOLFIRI + aflibercept versus FOLFIRI + placebo in metastatic colorectal cancer (mCRC) patients who progressed on oxaliplatin-based chemotherapy. Continued divergence of overall survival (OS) curves in the intension to treat (ITT) population, with the survival advantage persisting beyond median survival time, suggested subpopulations might have different magnitudes of survival gain. Additionally, 10% of patients within VELOUR had recurrence during or within 6 months of completing oxaliplatin-based adjuvant therapy (adjuvant fast relapsers) - previously identified as having poorer survival outcomes
SWAS and Arecibo observations of H2O and OH in a diffuse cloud along the line-of-sight to W51
Observations of W51 with the Submillimeter Wave Astronomy Satellite (SWAS)
have yielded the first detection of water vapor in a diffuse molecular cloud.
The water vapor lies in a foreground cloud that gives rise to an absorption
feature at an LSR velocity of 6 km/s. The inferred H2O column density is
2.5E+13 cm-2. Observations with the Arecibo radio telescope of hydroxyl
molecules at ten positions in W51 imply an OH column density of 8E+13 cm-2 in
the same diffuse cloud. The observed H2O/OH ratio of ~ 0.3 is significantly
larger than an upper limit derived previously from ultraviolet observations of
the similar diffuse molecular cloud lying in front of HD 154368. The observed
variation in H2O/OH likely points to the presence in one or both of these
clouds of a warm (T > 400) gas component in which neutral-neutral reactions are
important sources of OH and/or H2O.Comment: 15 pages (AASTeX) including 4 (eps) figures. To appear in the
Astrophysical Journa
Modeling semi-conductor thermal properties. The dispersion role
We study heat transport in semiconductor nanostructures by solving the
Boltzmann Transport Equation (BTE) by means of the Discrete Ordinate Method
(DOM). Relaxation time and phase and group velocitiy spectral dependencies are
taken into account. The Holland model of phonon relaxation time is revisited
and recalculated from dispersion relations (taken in litterature) in order to
match bulk silicon and germanium values. This improved model is then used to
predict silicon nanowire and nanofilm thermal properties in both ballistic and
mesoscopic regimes
Detection of interstellar CH_3
Observations with the Short Wavelength Spectrometer (SWS) onboard the {\it
Infrared Space Observatory} (ISO) have led to the first detection of the methyl
radical in the interstellar medium. The branch at 16.5
m and the (0) line at 16.0 m have been unambiguously detected
toward the Galactic center SgrA. The analysis of the measured bands gives a
column density of (8.02.4) cm and an excitation
temperature of K. Gaseous at a similarly low excitation
temperature and are detected for the same line of sight. Using
constraints on the column density obtained from and
visual extinction, the inferred abundance is
. The chemically related
molecule is not detected, but the pure rotational lines of are seen
with the Long Wavelength Spectrometer (LWS). The absolute abundances and the
and ratios are inconsistent with published
pure gas-phase models of dense clouds. The data require a mix of diffuse and
translucent clouds with different densities and extinctions, and/or the
development of translucent models in which gas-grain chemistry, freeze-out and
reactions of with polycyclic aromatic hydrocarbons and solid
aliphatic material are included.Comment: 2 figures. ApJL, Accepte
Electromagnetic field correlations near a surface with a nonlocal optical response
The coherence length of the thermal electromagnetic field near a planar
surface has a minimum value related to the nonlocal dielectric response of the
material. We perform two model calculations of the electric energy density and
the field's degree of spatial coherence. Above a polar crystal, the lattice
constant gives the minimum coherence length. It also gives the upper limit to
the near field energy density, cutting off its divergence. Near an
electron plasma described by the semiclassical Lindhard dielectric function,
the corresponding length scale is fixed by plasma screening to the Thomas-Fermi
length. The electron mean free path, however, sets a larger scale where
significant deviations from the local description are visible.Comment: 15 pages, 7 figure files (.eps), \documentclass[global]{svjour},
accepted in special issue "Optics on the Nanoscale" (Applied Physics B, eds.
V. Shalaev and F. Tr\"ager
Casimir force between designed materials: what is possible and what not
We establish strict upper limits for the Casimir interaction between
multilayered structures of arbitrary dielectric or diamagnetic materials. We
discuss the appearance of different power laws due to frequency-dependent
material constants. Simple analytical expressions are in good agreement with
numerical calculations based on Lifshitz theory. We discuss the improvements
required for current (meta) materials to achieve a repulsive Casimir force.Comment: 9 pages, 4 figures, graphicx, v4: Europhysics Letters, in pres
The role of gender and other factors as predictors of not receiving reperfusion therapy and of outcome in ST-segment elevation myocardial infarction
On the use of fractional Brownian motion simulations to determine the 3D statistical properties of interstellar gas
Based on fractional Brownian motion (fBm) simulations of 3D gas density and
velocity fields, we present a study of the statistical properties of
spectro-imagery observations (channel maps, integrated emission, and line
centroid velocity) in the case of an optically thin medium at various
temperatures. The power spectral index gamma_W of the integrated emission is
identified with that of the 3D density field (gamma_n) provided the medium's
depth is at least of the order of the largest transverse scale in the image,
and the power spectrum of the centroid velocity map is found to have the same
index gamma_C as that of the velocity field (gamma_v). Further tests with
non-fBm density and velocity fields show that this last result holds, and is
not modified either by the effects of density-velocity correlations. A
comparison is made with the theoretical predictions of Lazarian & Pogosyan
(2000).Comment: 28 pages, 14 figures, accepted for publication in ApJ. For preprint
with higher-resolution figures, see
http://www.cita.utoronto.ca/~mamd/miville_fbm2003.pd
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