1,391 research outputs found
An international cross-sectional survey of antimicrobial stewardship programmes in hospitals
Objectives To report the extent and components of global efforts in antimicrobial stewardship (AMS) in hospitals. Methods An Internet-based survey comprising 43 questions was disseminated worldwide in 2012. Results Responses were received from 660 hospitals in 67 countries: Africa, 44; Asia, 50; Europe, 361; North America, 72; Oceania, 30; and South and Central America, 103. National AMS standards existed in 52% of countries, 4% were planning them and 58% had an AMS programme. The main barriers to implementing AMS programmes were perceived to be a lack of funding or personnel, a lack of information technology and prescriber opposition. In hospitals with an existing AMS programme, AMS rounds existed in 64%; 81% restricted antimicrobials (carbapenems, 74.3%; quinolones, 64%; and cephalosporins, 58%); and 85% reported antimicrobial usage, with 55% linking data to resistance rates and 49% linking data to infection rates. Only 20% had electronic prescribing for all patients. A total of 89% of programmes educated their medical, nursing and pharmacy staff on AMS. Of the hospitals, 38% had formally reviewed their AMS programme: reductions were reported by 96% of hospitals for inappropriate prescribing, 86% for broad-spectrum antibiotic use, 80% for expenditure, 71% for healthcare-acquired infections, 65% for length of stay or mortality and 58% for bacterial resistance. Conclusions The worldwide development and implementation of AMS programmes varies considerably. Our results should inform and encourage the further evaluation of this with a view to promoting a worldwide stewardship framework. The prospective measurement of well-defined outcomes of the impact of these programmes remains a significant challeng
“Ten Commandments” for the Appropriate use of Antibiotics by the Practicing Physician in an Outpatient Setting
A multi-national working group on antibiotic stewardship, from the International Society of Chemotherapy, put together ten recommendations to physicians prescribing antibiotics to outpatients. These recommendations are: (1) use antibiotics only when needed; teach the patient how to manage symptoms of non-bacterial infections; (2) select the adequate ATB; precise targeting is better than shotgun therapy; (3) consider pharmacokinetics and pharmacodynamics when selecting an ATB; use the shortest ATB course that has proven clinical efficacy; (4) encourage patients’ compliance; (5) use antibiotic combinations only in specific situations; (6) avoid low quality and sub-standard drugs; prevent prescription changes at the drugstore; (7) discourage self-prescription; (8) follow only evidence-based guidelines; beware those sponsored by drug companies; (9) rely (rationally) upon the clinical microbiology lab; and (10) prescribe ATB empirically – but intelligently; know local susceptibility trends, and also surveillance limitations
Measurement of the Helicity Fractions of W Bosons from Top Quark Decays Using Fully Reconstructed top-antitop Events with CDF II
We present a measurement of the fractions F_0 and F_+ of longitudinally
polarized and right-handed W bosons in top quark decays using data collected
with the CDF II detector. The data set used in the analysis corresponds to an
integrated luminosity of approximately 318 pb -1. We select ttbar candidate
events with one lepton, at least four jets, and missing transverse energy. Our
helicity measurement uses the decay angle theta*, which is defined as the angle
between the momentum of the charged lepton in the W boson rest frame and the W
momentum in the top quark rest frame. The cos(theta*) distribution in the data
is determined by full kinematic reconstruction of the ttbar candidates. We find
F_0 = 0.85 +0.15 -0.22 (stat) +- 0.06 (syst) and F_+ = 0.05 +0.11 -0.05 (stat)
+- 0.03 (syst), which is consistent with the standard model prediction. We set
an upper limit on the fraction of right-handed W bosons of F_+ < 0.26 at the
95% confidence level.Comment: 11 pages, 2 figures, submitted to Phys. Rev.
Search for the Higgs boson in events with missing transverse energy and b quark jets produced in proton-antiproton collisions at s**(1/2)=1.96 TeV
We search for the standard model Higgs boson produced in association with an
electroweak vector boson in events with no identified charged leptons, large
imbalance in transverse momentum, and two jets where at least one contains a
secondary vertex consistent with the decay of b hadrons. We use ~1 fb-1
integrated luminosity of proton-antiproton collisions at s**(1/2)=1.96 TeV
recorded by the CDF II experiment at the Tevatron. We find 268 (16) single
(double) b-tagged candidate events, where 248 +/- 43 (14.4 +/- 2.7) are
expected from standard model background processes. We place 95% confidence
level upper limits on the Higgs boson production cross section for several
Higgs boson masses ranging from 110 GeV/c2 to 140 GeV/c2. For a mass of 115
GeV/c2 the observed (expected) limit is 20.4 (14.2) times the standard model
prediction.Comment: 8 pages, 2 figures, submitted to Phys. Rev. Let
Observation and Mass Measurement of the Baryon
We report the observation and measurement of the mass of the bottom, strange
baryon through the decay chain , where
, , and .
Evidence for observation is based on a signal whose probability of arising from
the estimated background is 6.6 x 10^{-15}, or 7.7 Gaussian standard
deviations. The mass is measured to be (stat.) (syst.) MeV/.Comment: Minor text changes for the second version. Accepted by Phys. Rev.
Let
First Measurement of the W Boson Mass in Run II of the Tevatron
We present a measurement of the W boson mass using 200/pb of data collected
in pbar p collisions at sqrt(s) = 1.96 TeV by the CDF II detector at Run II of
the Fermilab Tevatron. With a sample of 63964 W -> e nu candidates and 51128 W
-> mu nu candidates, we measure M_W = (80413 +- 34 (stat) +- 34 (syst) = 80413
+- 48) MeV/c^2. This is the most precise single measurement of the W boson mass
to date.Comment: published version in PR
Polarizations of J/psi and psi(2S) Mesons Produced in ppbar Collisions at 1.96 TeV
We have measured the polarizations of \jpsi and \psiprime mesons as
functions of their transverse momentum \pt when they are produced promptly in
the rapidity range with \pt \geq 5 \pgev. The analysis is performed
using a data sample with an integrated luminosity of about 800 \ipb collected
by the CDF II detector. For both vector mesons, we find that the polarizations
become increasingly longitudinal as \pt increases from 5 to 30 \pgev. These
results are compared to the predictions of nonrelativistic quantum
chromodynamics and other contemporary models. The effective polarizations of
\jpsi and \psiprime mesons from -hadron decays are also reported.Comment: 8 pages, 7 figures, published in Physical Review Letter
Search for Third Generation Vector Leptoquarks in p anti-p Collisions at sqrt(s) = 1.96 TeV
We describe a search for a third generation vector leptoquark (VLQ3) that
decays to a b quark and tau lepton using the CDF II detector and 322 pb^(-1) of
integrated luminosity from the Fermilab Tevatron. Vector leptoquarks have been
proposed in many extensions of the standard model (SM). Observing a number of
events in agreement with SM expectations, assuming Yang-Mills (minimal)
couplings, we obtain the most stringent upper limit on the VLQ3 pair production
cross section of 344 fb (493 fb) and lower limit on the VLQ3 mass of 317
GeV/c^2 (251 GeV/c^2) at 95% C.L.Comment: 7 pages, 2 figures, submitted to PR
Searches for Direct Pair Production of Supersymmetric Top and Supersymmetric Bottom Quarks in p-pbar Collisions at sqrt(s)=1.96 TeV
We search for direct pair production of supersymmetric top quarks and
supersymmetric bottom quarks in proton-antiproton collisions at sqrt(s)=1.96
TeV, using 295 pb^-1 of data recorded by the Collider Detector at Fermilab (CDF
II) experiment. The supersymmetric top (supersymmetric bottom) quarks are
selected by reconstructing their decay into a charm (bottom) quark and a
neutralino, which is assumed to be the lightest supersymmetric particle. The
signature of such processes is two energetic heavy-flavor jets and missing
transverse energy. The number of events that pass our selection for each search
process is consistent with the expected standard model background. By comparing
our results to the theoretical production cross sections of the supersymmetric
top and supersymmetric bottom quarks in the minimal supersymmetric standard
model, we exclude, at a 95% confidence level in the frame of that model, a
supersymmetric top quark mass up to 132 GeV/c^2 for a neutralino mass of 48
GeV/c^2, and a supersymmetric bottom quark mass up to 193 GeV/c^2 for a
neutralino mass of 40 GeV/c^2.Comment: 12 pages, 5 figures, submitted to Phys. Rev.
Precise measurement of the top quark mass in the lepton+jets topology at CDF II
We present a measurement of the mass of the top quark from proton-antiproton
collisions recorded at the CDF experiment in Run II of the Fermilab Tevatron.
We analyze events from the single lepton plus jets final state (). The top quark mass is extracted
using a direct calculation of the probability density that each event
corresponds to the final state. The probability is a function of both
the mass of the top quark and the energy scale of the calorimeter jets, which
is constrained {\it in situ} by the hadronic boson mass. Using 167 events
observed in 955 pb of integrated luminosity, we achieve the single
most precise measurement of the top quark mass, 170.8 2.2 (stat.)
1.4 (syst.) GeV/.Comment: accepted by Phys. Rev. Let
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