707 research outputs found
Reduction in intraoperative bacterial contamination of peripheral intravenous tubing through the use of a novel device
Background: Hand hygiene is a vital intervention to reduce health-care associated infections, but compliance remains low. The authors hypothesized that improvements in intraoperative hand hygiene compliance would reduce transmission of bacteria to surgical patients and reduce the incidence of postsurgical healthcare-associated infections. Methods: The authors performed a controlled before-andafter study over 2 consecutive months. One hundred fourteen operative cases were enrolled. Two predesignated sites on the anesthesia machine were selected, decontaminated, and cultured via aseptic technique. These sites and the peripheral intravenous stopcock were cultured again after completion of the surgery. The treatment phase used a novel personal handdecontamination device capable of recording hand-decontamination events. Results: There were no significant differences in patient location, age, or case duration and procedure type between groups. Use of the Sprixx GJ device (Harbor Medical Inc., Santa Barbara, CA) increased hourly hand decontamination events by 27-fold as compared with baseline rates (P < 0.002; 95% confidence interval, 3.3-13.4). Use of the device was associated with a reduction in contamination in the anesthesia work area and peripheral intravenous tubing. Intravenous tubing contamination was identified in 32.8% of cases in the control group versus 7.5% in the treatment group (odds ratio, 0.17; 95% confidence interval, 0.06 -0.51; P < 0.01). Healthcare-associated infections rates were reduced in the device group (3.8%) as compared with the control group (17.2%) (odds ratio, 0.19; 95% confidence interval, 0.00 -0.81; P ؍ 0.02). Conclusions: Improved hand hygiene compliance through the use of a novel hand sanitation strategy reduces the risk of intraoperative bacterial transmission. The interventio
Self Consistent Molecular Field Theory for Packing in Classical Liquids
Building on a quasi-chemical formulation of solution theory, this paper
proposes a self consistent molecular field theory for packing problems in
classical liquids, and tests the theoretical predictions for the excess
chemical potential of the hard sphere fluid. Results are given for the self
consistent molecular fields obtained, and for the probabilities of occupancy of
a molecular observation volume. For this system, the excess chemical potential
predicted is as accurate as the most accurate prior theories, particularly the
scaled particle (Percus-Yevick compressibility) theory. It is argued that the
present approach is particularly simple, and should provide a basis for a
molecular-scale description of more complex solutions.Comment: 6 pages and 5 figure
High Magnetic Field NMR Studies of LiVGeO, a quasi 1-D Spin System
We report Li pulsed NMR measurements in polycrystalline and single
crystal samples of the quasi one-dimensional S=1 antiferromagnet
LiVGeO, whose AF transition temperature is K.
The field () and temperature () ranges covered were 9-44.5 T and
1.7-300 K respectively. The measurements included NMR spectra, the spin-lattice
relaxation rate (), and the spin-phase relaxation rate (),
often as a function of the orientation of the field relative to the crystal
axes. The spectra indicate an AF magnetic structure consistent with that
obtained from neutron diffraction measurements, but with the moments aligned
parallel to the c-axis. The spectra also provide the -dependence of the AF
order parameter and show that the transition is either second order or weakly
first order. Both the spectra and the data show that has at
most a small effect on the alignment of the AF moment. There is no spin-flop
transition up to 44.5 T. These features indicate a very large magnetic
anisotropy energy in LiVGeO with orbital degrees of freedom playing an
important role. Below 8 K, varies substantially with the orientation
of in the plane perpendicular to the c-axis, suggesting a small energy
gap for magnetic fluctuations that is very anisotropic.Comment: submitted to Phys. Rev.
Study of the production of and hadrons in collisions and first measurement of the branching fraction
The product of the () differential production
cross-section and the branching fraction of the decay () is
measured as a function of the beauty hadron transverse momentum, ,
and rapidity, . The kinematic region of the measurements is and . The measurements use a data sample
corresponding to an integrated luminosity of collected by the
LHCb detector in collisions at centre-of-mass energies in 2011 and in 2012. Based on previous LHCb
results of the fragmentation fraction ratio, , the
branching fraction of the decay is
measured to be \begin{equation*} \mathcal{B}(\Lambda_b^0\rightarrow J/\psi
pK^-)= (3.17\pm0.04\pm0.07\pm0.34^{+0.45}_{-0.28})\times10^{-4},
\end{equation*} where the first uncertainty is statistical, the second is
systematic, the third is due to the uncertainty on the branching fraction of
the decay , and the
fourth is due to the knowledge of . The sum of the
asymmetries in the production and decay between and
is also measured as a function of and .
The previously published branching fraction of , relative to that of , is updated.
The branching fractions of are determined.Comment: 29 pages, 19figures. All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-032.htm
Evidence for the strangeness-changing weak decay
Using a collision data sample corresponding to an integrated luminosity
of 3.0~fb, collected by the LHCb detector, we present the first search
for the strangeness-changing weak decay . No
hadron decay of this type has been seen before. A signal for this decay,
corresponding to a significance of 3.2 standard deviations, is reported. The
relative rate is measured to be
, where and
are the and fragmentation
fractions, and is the branching
fraction. Assuming is bounded between 0.1 and
0.3, the branching fraction would lie
in the range from to .Comment: 7 pages, 2 figures, All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm
flavour tagging using charm decays at the LHCb experiment
An algorithm is described for tagging the flavour content at production of
neutral mesons in the LHCb experiment. The algorithm exploits the
correlation of the flavour of a meson with the charge of a reconstructed
secondary charm hadron from the decay of the other hadron produced in the
proton-proton collision. Charm hadron candidates are identified in a number of
fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is
calibrated on the self-tagged decay modes and using of data collected by the LHCb
experiment at centre-of-mass energies of and
. Its tagging power on these samples of
decays is .Comment: All figures and tables, along with any supplementary material and
additional information, are available at
http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-027.htm
Measurements of long-range near-side angular correlations in TeV proton-lead collisions in the forward region
Two-particle angular correlations are studied in proton-lead collisions at a
nucleon-nucleon centre-of-mass energy of TeV, collected
with the LHCb detector at the LHC. The analysis is based on data recorded in
two beam configurations, in which either the direction of the proton or that of
the lead ion is analysed. The correlations are measured in the laboratory
system as a function of relative pseudorapidity, , and relative
azimuthal angle, , for events in different classes of event
activity and for different bins of particle transverse momentum. In
high-activity events a long-range correlation on the near side, , is observed in the pseudorapidity range . This
measurement of long-range correlations on the near side in proton-lead
collisions extends previous observations into the forward region up to
. The correlation increases with growing event activity and is found
to be more pronounced in the direction of the lead beam. However, the
correlation in the direction of the lead and proton beams are found to be
compatible when comparing events with similar absolute activity in the
direction analysed.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-040.htm
Azimuthal anisotropy at RHIC: the first and fourth harmonics
We report the first observations of the first harmonic (directed flow, v_1),
and the fourth harmonic (v_4), in the azimuthal distribution of particles with
respect to the reaction plane in Au+Au collisions at the Relativistic Heavy Ion
Collider (RHIC). Both measurements were done taking advantage of the large
elliptic flow (v_2) generated at RHIC. From the correlation of v_2 with v_1 it
is determined that v_2 is positive, or {\it in-plane}. The integrated v_4 is
about a factor of 10 smaller than v_2. For the sixth (v_6) and eighth (v_8)
harmonics upper limits on the magnitudes are reported.Comment: 6 pages with 3 figures, as accepted for Phys. Rev. Letters The data
tables are at
http://www.star.bnl.gov/central/publications/pubDetail.php?id=3
Measurement of the inclusive isolated prompt photon cross-section in pp collisions at sqrt(s)= 7 TeV using 35 pb-1 of ATLAS data
A measurement of the differential cross-section for the inclusive production
of isolated prompt photons in pp collisions at a center-of-mass energy sqrt(s)
= 7 TeV is presented. The measurement covers the pseudorapidity ranges
|eta|<1.37 and 1.52<=|eta|<2.37 in the transverse energy range 45<=E_T<400GeV.
The results are based on an integrated luminosity of 35 pb-1, collected with
the ATLAS detector at the LHC. The yields of the signal photons are measured
using a data-driven technique, based on the observed distribution of the
hadronic energy in a narrow cone around the photon candidate and the photon
selection criteria. The results are compared with next-to-leading order
perturbative QCD calculations and found to be in good agreement over four
orders of magnitude in cross-section.Comment: 7 pages plus author list (18 pages total), 2 figures, 4 tables, final
version published in Physics Letters
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