8,029 research outputs found
Oral platelet gel supernatant plus supportive medical treatment versus supportive medical treatment in the management of radiation-induced oral mucositis: a matched explorative active control trial by propensity analysis
OBJECTIVES:: In this active control trial, the rate of radio-induced WHO grade 3/4 oral mucositis and the change in quality of life, assessed by OMWQ-HN, were measured in subjects with head and neck cancer treated by platelet gel supernatant (PGS) and supportive medical treatment versus subjects treated by supportive medical treatment alone. MATERIALS AND METHODS:: Eighty patients with nonmetastatic head and neck cancer underwent curative or adjuvant radiotherapy. All patients underwent supportive medical treatment and/or PGS at the beginning and during radiotherapy. Sixteen patients received PGS in association with supportive medical treatment. To obtain 2 groups virtually randomized for important clinical characteristics subjects were matched, by propensity analysis, with a group of subjects (64 patients) treated with supportive medical treatment alone. RESULTS:: Subjects treated with standard supportive treatment experienced significant higher WHO grade 3/4 toxicity (55%; 35/64) than subjects treated by PGS (13%; 3/16). The reduced toxicity found in PGS group paralleled with the evidence that they developed later symptoms with respect to controls. The Cox proportional hazard model indicated that patients treated with standard supportive medical treatment experienced 2.7-fold increase (hazard ratio=2.7; 95% confidence interval, 1.3-5.7) in the occurrence of WHO grade 3/4 toxicity. PGS group significantly experienced higher quality of life than control groups as measured by OMWQ-HN. A significant decrease in the opioid analgesics usage was found in the PGS group. CONCLUSIONS:: These preliminary data should be interpreted with caution and could serve as a framework around which to design future trials
The Evolution of FTK, a Real-Time Tracker for Hadron Collider Experiments
We describe the architecture evolution of the highly-parallel dedicated
processor FTK, which is driven by the simulation of LHC events at high
luminosity (1034 cm-2 s-1). FTK is able to provide precise on-line track
reconstruction for future hadronic collider experiments. The processor,
organized in a two-tiered pipelined architecture, execute very fast algorithms
based on the use of a large bank of pre-stored patterns of trajectory points
(first tier) in combination with full resolution track fitting to refine
pattern recognition and to determine off-line quality track parameters. We
describe here how the high luminosity simulation results have produced a new
organization of the hardware inside the FTK processor core.Comment: 11th ICATPP conferenc
Development of FTK architecture: a fast hardware track trigger for the ATLAS detector
The Fast Tracker (FTK) is a proposed upgrade to the ATLAS trigger system that
will operate at full Level-1 output rates and provide high quality tracks
reconstructed over the entire detector by the start of processing in Level-2.
FTK solves the combinatorial challenge inherent to tracking by exploiting the
massive parallelism of Associative Memories (AM) that can compare inner
detector hits to millions of pre-calculated patterns simultaneously. The
tracking problem within matched patterns is further simplified by using
pre-computed linearized fitting constants and leveraging fast DSP's in modern
commercial FPGA's. Overall, FTK is able to compute the helix parameters for all
tracks in an event and apply quality cuts in approximately one millisecond. By
employing a pipelined architecture, FTK is able to continuously operate at
Level-1 rates without deadtime. The system design is defined and studied using
ATLAS full simulation. Reconstruction quality is evaluated for single muon
events with zero pileup, as well as WH events at the LHC design luminosity. FTK
results are compared with the tracking capability of an offline algorithm.Comment: To be published in the proceedings of DPF-2009, Detroit, MI, July
2009, eConf C09072
Combined search for the standard model Higgs boson decaying to a bb pair using the full CDF data set
We combine the results of searches for the standard model Higgs boson based
on the full CDF Run II data set obtained from sqrt(s) = 1.96 TeV p-pbar
collisions at the Fermilab Tevatron corresponding to an integrated luminosity
of 9.45/fb. The searches are conducted for Higgs bosons that are produced in
association with a W or Z boson, have masses in the range 90-150 GeV/c^2, and
decay into bb pairs. An excess of data is present that is inconsistent with the
background prediction at the level of 2.5 standard deviations (the most
significant local excess is 2.7 standard deviations).Comment: To be published in Phys. Rev. Lett (v2 contains minor updates based
on comments from PRL
Measurement of the Associated Production Cross Section in Collisions at TeV
We present the first measurement of associated direct photon + muon
production in hadronic collisions, from a sample of 1.8 TeV
collisions recorded with the Collider Detector at Fermilab. Quantum
chromodynamics (QCD) predicts that these events are primarily from the Compton
scattering process , with the final state charm quark producing
a muon. Hence this measurement is sensitive to the charm quark content of the
proton. The measured cross section of is compared to a
leading-order QCD parton shower model as well as a next-to-leading-order QCD
calculation.Comment: 12 pages, 4 figures Added more detailed description of muon
background estimat
Measurements of branching fraction ratios and CP-asymmetries in suppressed B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^- decays
We report the first reconstruction in hadron collisions of the suppressed
decays B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^-, sensitive to the
CKM phase gamma, using data from 7 fb^-1 of integrated luminosity collected by
the CDF II detector at the Tevatron collider. We reconstruct a signal for the
B^- -> D(-> K^+ pi^-)K^- suppressed mode with a significance of 3.2 standard
deviations, and measure the ratios of the suppressed to favored branching
fractions R(K) = [22.0 \pm 8.6(stat)\pm 2.6(syst)]\times 10^-3, R^+(K) =
[42.6\pm 13.7(stat)\pm 2.8(syst)]\times 10^-3, R^-(K)= [3.8\pm 10.3(stat)\pm
2.7(syst]\times 10^-3, as well as the direct CP-violating asymmetry A(K) =
-0.82\pm 0.44(stat)\pm 0.09(syst) of this mode. Corresponding quantities for
B^- -> D(-> K^+ pi^-)pi^- decay are also reported.Comment: 8 pages, 1 figure, accepted by Phys.Rev.D Rapid Communications for
Publicatio
Observation of the Baryonic Flavor-Changing Neutral Current Decay Lambda_b -> Lambda mu+ mu-
We report the first observation of the baryonic flavor-changing neutral
current decay Lambda_b -> Lambda mu+ mu- with 24 signal events and a
statistical significance of 5.8 Gaussian standard deviations. This measurement
uses ppbar collisions data sample corresponding to 6.8fb-1 at sqrt{s}=1.96TeV
collected by the CDF II detector at the Tevatron collider. The total and
differential branching ratios for Lambda_b -> Lambda mu+ mu- are measured. We
find B(Lambda_b -> Lambda mu+ mu-) = [1.73+-0.42(stat)+-0.55(syst)] x 10^{-6}.
We also report the first measurement of the differential branching ratio of B_s
-> phi mu+ mu- using 49 signal events. In addition, we report branching ratios
for B+ -> K+ mu+ mu-, B0 -> K0 mu+ mu-, and B -> K*(892) mu+ mu- decays.Comment: 8 pages, 2 figures, 4 tables. Submitted to Phys. Rev. Let
Measurement of CP-violation asymmetries in D0 to Ks pi+ pi-
We report a measurement of time-integrated CP-violation asymmetries in the
resonant substructure of the three-body decay D0 to Ks pi+ pi- using CDF II
data corresponding to 6.0 invfb of integrated luminosity from Tevatron ppbar
collisions at sqrt(s) = 1.96 TeV. The charm mesons used in this analysis come
from D*+(2010) to D0 pi+ and D*-(2010) to D0bar pi-, where the production
flavor of the charm meson is determined by the charge of the accompanying pion.
We apply a Dalitz-amplitude analysis for the description of the dynamic decay
structure and use two complementary approaches, namely a full Dalitz-plot fit
employing the isobar model for the contributing resonances and a
model-independent bin-by-bin comparison of the D0 and D0bar Dalitz plots. We
find no CP-violation effects and measure an asymmetry of ACP = (-0.05 +- 0.57
(stat) +- 0.54 (syst))% for the overall integrated CP-violation asymmetry,
consistent with the standard model prediction.Comment: 15 page
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
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