130 research outputs found
The Benefits of Combined Anti-platelet Treatment in Carotid Artery Stenting
AbstractObjectiveTo assess the benefits of a combined anti-platelet regime of aspirin and clopidogrel in carotid artery stenting.MethodsA randomised controlled trial was performed comparing aspirin and 24-h heparin with aspirin and clopidogrel for patients undergoing carotid artery stenting. Outcome measures included 30-day bleeding and neurological complications and 30-day stenosis rates.ResultsBleeding complications (groin haematoma or excessive bleeding at the groin site) occurred in 17% of the heparin and 9% of the clopidogrel group (p=0.35; n.s). The neurological complication rate in the 24-h heparin group was 25% compared to 0% in the clopidogrel group (p=0.02). The 30-day 50–100% stenosis rates were 26% in the heparin group and 5% in the clopidogrel group (p=0.10; n.s).ConclusionsThe dual anti-platelet regime has a significant impact on reducing adverse neurological outcomes without an additional increase in bleeding complications. This study was terminated prematurely due to an unacceptable level of complications in the heparin arm of the trial
Safety of Arch Aortography for Assessment of Carotid Arteries
AbstractPurposeTo retrospectively review the safety of arch aortography and compare complication rates with published figures for selective catheter angiography.MethodsThe medical records of patients undergoing arch aortography over the last 3 years (n=311; 180 male, 131 female; mean±SD age 71.0±9.2 years, range 42–90 years) were retrospectively reviewed. Any peri-procedural (0–48h) complications were recorded. A certified neurologist (MSR/GSV) classified all questionable neurological events.ResultsThere were no focal neurological events or deaths (n=0; 0%; CI: 0–0.96%). Non-focal neurological events included mild disorientation (n=2; 0.6%; CI: 0.176–2.31) and unequal pupils (n=1; 0.3%; CI: 0.056–1.79%). Cardiovascular events included symptomatic hypotension (n=4; 1.3%; CI: 0.50–3.25%), angina (n=1; 0.3%; CI: 0.056–1.79%) and arrhythmia (n=4; 1.3%; CI: 0.50–3.25). There were 27 minor access site complications (8.7%; CI: 6.0–12.3). None of these complications extended hospital stay. None of the arch angiograms had to be followed by selective carotid angiography.ConclusionArch aortography appears to have a lower neurological complication rate than selective carotid angiography
Effects of cetylpyridinium chloride treatment of roast beef on Listeria monocytogenes populations and quality attributes
The effectiveness of cetylpyridinium chloride
(CPC) for reducing microbial populations,
in particular Listeria monocytogenes, on
ready-to-eat roast beef was evaluated. Roast
beef slices inoculated with L. monocytogenes
were dipped in a solution of 1% CPC for 1
minute. Samples were then vacuum packaged
and stored at refrigeration temperature. The
effects of CPC treatment on microbial populations, as well as on color and texture of the roast beef samples, was evaluated over a 42-day period. Immediately after CPC treatment, L. monocytogenes populations were reduced by 99 to 99.99%, with the treatment being somewhat more effective on exterior than on sliced/cut surfaces. Throughout 42 days of refrigerated storage, populations of L. monocytogenes, total bacteria, and lactic acid bacteria remained lower on CPC-treated samples than on non-treated samples. Treatment with CPC did not significantly affect the color or texture of roast beef. Treatment with CPC, especially when applied to products before slicing, may serve as an effective antimicrobial intervention for ready-to-eat meat products
Cosmological Effects of Radion Oscillations
We show that the redshift of pressureless matter density due to the expansion
of the universe generically induces small oscillations in the stabilized radius
of extra dimensions (the radion field). The frequency of these oscillations is
proportional to the mass of the radion and can have interesting cosmological
consequences. For very low radion masses () these low frequency oscillations lead to oscillations in
the expansion rate of the universe. The occurrence of acceleration periods
could naturally lead to a resolution of the coincidence problem, without need
of dark energy. Even though this scenario for low radion mass is consistent
with several observational tests it has difficulty to meet fifth force
constraints. If viewed as an effective Brans-Dicke theory it predicts
( is the number of extra dimensions), while
experiments on scales larger than imply . By deriving the
generalized Newtonian potential corresponding to a massive toroidally compact
radion we demonstrate that Newtonian gravity is modified only on scales smaller
than . Thus, these constraints do not apply for
(high frequency oscillations) corresponding to scales less than the current
experiments (). Even though these high frequency oscillations can not
resolve the coincidence problem they provide a natural mechanism for dark
matter generation. This type of dark matter has many similarities with the
axion.Comment: Accepted in Phys. Rev. D. Clarifying comments added in the text and
some additional references include
Extra Dimensions at the Weak Scale and Deviations from Newtonian Gravity
We consider theories in which the Standard Model gauge fields propagate in
extra dimensions whose size is around the electroweak scale. The Standard Model
quarks and leptons may either be localized to a brane or propagate in the bulk.
This class of theories includes models of Scherk-Schwarz supersymmetry
breaking and universal extra dimensions. We consider the problem of stabilizing
the volume of the extra dimensions. We find that for a large class of
stabilization mechanisms the field which corresponds to fluctuations of the
volume remains light even after stabilization, and has a mass in the
eV range. In particular this is the case if stabilization does not involve
dynamics at scales larger than the cutoff of the higher dimensional Standard
Model, and if the effective theory below the compactification scale is four
dimensional. The mass of this field is protected against large radiative
corrections by the general covariance of the higher dimensional theory and by
the weakness of its couplings, which are Planck suppressed. Its couplings to
matter mediate forces whose strength is comparable to that of gravity and which
can give rise to potentially observable deviations from Newton's Law at
sub-millimeter distances. Current experiments investigating short distance
gravity can probe extra dimensions too small to be accessible to current
collider experiments. In particular for a single extra dimension stabilized by
the Casimir energy of the Standard Model fields compactification radii as small
as 5 inverse TeV are accessible to current sub-millimeter gravity experiments.Comment: Minor corrections, conclusions unchanged. References adde
A Small Molecule that Induces Intrinsic Pathway Apoptosis with Unparalleled Speed
Apoptosis is generally believed to be a process thatrequires several hours, in contrast to non-programmed forms of cell death that can occur in minutes. Our findings challenge the time-consuming nature of apoptosis as we describe the discovery and characterization of a small molecule, named Raptinal, which initiates intrinsic pathway caspase-dependent apoptosis within minutes in multiple cell lines. Comparison to a mechanistically diverse panel of apoptotic stimuli reveals that Raptinal-induced apoptosis proceeds with unparalleled speed. The rapid phenotype enabled identification of the criticalroles of mitochondrial voltage-dependent anion channel function, mitochondrial membrane potential/coupled respiration, and mitochondrial complex I, III, and IV function for apoptosis induction. Use of Raptinal in whole organisms demonstrates its utility for studying apoptosis invivo for a variety of applications. Overall, rapid inducers of apoptosis are powerful tools that will be used in a variety of settings to generate further insight into the apoptotic machinery. Palchaudhuri etal. describe the discovery of a small molecule called "Raptinal" that induces unusually rapid apoptotic cell death via the intrinsic pathway. Their work describes the utility of Raptinal as a tool for apoptosis induction relative to other available small molecules
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Black Holes at the LHC
In these two lectures, we will address the topic of the creation of small
black holes during particle collisions in a ground-based accelerator, such as
LHC, in the context of a higher-dimensional theory. We will cover the main
assumptions, criteria and estimates for their creation, and we will discuss
their properties after their formation. The most important observable effect
associated with their creation is likely to be the emission of Hawking
radiation during their evaporation process. After presenting the mathematical
formalism for its study, we will review the current results for the emission of
particles both on the brane and in the bulk. We will finish with a discussion
of the methodology that will be used to study these spectra, and the observable
signatures that will help us identify the black-hole events.Comment: 37 pages, 14 figures, lectures presented in the 4th Aegean Summer
School on Black Holes, 17-22 September 2007, Lesvos, Greece, typos corrected,
comments and references adde
Evaluation of skin sensitivity in dogs bearing allergic dermatitis to standardized allergenic extract of house dust and storage mites
Search for TeV-scale gravity signatures in high-mass final states with leptons and jets with the ATLAS detector at sqrt [ s ] = 13TeV
A search for physics beyond the Standard Model, in final states with at least one high transverse momentum charged lepton (electron or muon) and two additional high transverse momentum leptons or jets, is performed using 3.2 fb−1 of proton–proton collision data recorded by the ATLAS detector at the Large Hadron Collider in 2015 at √s = 13 TeV. The upper end of the distribution of the scalar sum of the transverse momenta of leptons and jets is sensitive to the production of high-mass objects. No excess of events beyond Standard Model predictions is observed. Exclusion limits are set for models of microscopic black holes with two to six extra dimensions
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