462 research outputs found
Preliminary Studies of Magnetic NDE Techniques for Identifying Neutron Embrittlement of Pressure Vessel Steel
In operating nuclear reactors, the steel pressure vessel is exposed to neutron irradiation. The high energy part (\u3e1 MeV) of this irradiation, over a long period, makes the steel brittle and susceptible to rupture
Effect of preoperative oral antibiotics in combination with mechanical bowel preparation on inflammatory response and shortâterm outcomes following leftâsided colonic and rectal resections
Background:
Preoperative oral antibiotics in addition to intravenous antibiotics and mechanical bowel preparation (MBP) may influence the gut microbiome and reduce both the postoperative systemic inflammatory response to surgery and postoperative infective complications following colorectal resection. This propensity scoreâmatched study compared outcomes of patients undergoing leftâsided colonic or rectal resection with or without a combination of oral antibiotics and MBP.
Methods:
The addition of oral antibiotics and MBP to prophylactic intravenous antibiotics in leftâsided colonic and rectal resections was introduced in 2015â2016 at a single institution. Propensity score matching was undertaken to compare the effects of oral antibiotics plus MBP versus neither oral antibiotics nor MBP on the postoperative systemic inflammatory response and shortâterm outcomes in patients undergoing leftâsided colonic or rectal resection between 2013 and 2018.
Results:
Of 396 patients who had propensity score matching for host, anaesthetic and operative factors, 204 matched patients were identified. The addition of oral antibiotics and MBP was associated with a significantly reduced postoperative inflammatory response (reduced postoperative Glasgow Prognostic Score) on dayâ3 (odds ratio (OR) 0·66, 95 per cent c.i. 0·44 to 0·99; P â=â0·013) and dayâ4 (OR 0·46, 0·30 to 0·71; P â=â0·001). Significantly reduced overall complications (OR 0·31, 0·17 to 0·56; P â<â0·001), infective complications (OR 0·41, 0·22 to 0·77; P â=â0·011), surgicalâsite infection (OR 0·37, 0·17 to 0·83; P â=â0·024) and postoperative length of hospital stay (median 7âdays versus 8âdays in patients who had intravenous antibiotics alone; P â=â0·050) were also observed.
Conclusion:
Preoperative oral antibiotics and MBP in addition to prophylactic intravenous antibiotics were associated with a reduction in the postoperative systemic inflammatory response and postoperative complications in patients undergoing resectional leftâsided colonic or rectal surgery
Authors' reply: Effect of preoperative oral antibiotics in combination with mechanical bowel preparation on inflammatory response and short-term outcomes following left-sided colonic and rectal resections
No abstract available
Low-temperature co-sintering for fabrication of zirconia/ceria bi-layer electrolyte via tape casting using a Fe2O3 sintering aid
Bilayer electrolytes have potential in solid oxide cells to improve ionic conduction whilst blocking electronic
conduction. GDC/YSZ bilayer electrolyte processinghas provenproblematic due to thermochemical
instability at high sintering temperatures. We first match the shrinkage profile of the two bulk materials
using a Fe2O3 sintering additive. Additions of 5 mol% of Fe2O3 in the GDC layer and 2 mol% of Fe2O3 in
the YSZ layer prevents delamination during co-sintering. The addition of Fe2O3 promotes densification,
enabling achievement of a dense bilayer at a reduced sintering temperature of 1300 âŠC; âŒ150 âŠC below
conventional sintering temperatures. Elemental analysis showed the compositional distribution curves
across the bilayer interface to be asymmetric when Fe2O3 is employed. The Fe2O3 increases the total
conductivity of the bilayer electrolyte by an order of magnitude; this is explained by the effect of Fe2O3
on reducing the resistive solid solution interlayer at YSZ/GDC interface from âŒ15 to âŒ5 m
Astroparticle Physics with a Customized Low-Background Broad Energy Germanium Detector
The MAJORANA Collaboration is building the MAJORANA DEMONSTRATOR, a 60 kg
array of high purity germanium detectors housed in an ultra-low background
shield at the Sanford Underground Laboratory in Lead, SD. The MAJORANA
DEMONSTRATOR will search for neutrinoless double-beta decay of 76Ge while
demonstrating the feasibility of a tonne-scale experiment. It may also carry
out a dark matter search in the 1-10 GeV/c^2 mass range. We have found that
customized Broad Energy Germanium (BEGe) detectors produced by Canberra have
several desirable features for a neutrinoless double-beta decay experiment,
including low electronic noise, excellent pulse shape analysis capabilities,
and simple fabrication. We have deployed a customized BEGe, the MAJORANA
Low-Background BEGe at Kimballton (MALBEK), in a low-background cryostat and
shield at the Kimballton Underground Research Facility in Virginia. This paper
will focus on the detector characteristics and measurements that can be
performed with such a radiation detector in a low-background environment.Comment: Submitted to NIMA Proceedings, SORMA XII. 9 pages, 4 figure
Measurement of the p-pbar -> Wgamma + X cross section at sqrt(s) = 1.96 TeV and WWgamma anomalous coupling limits
The WWgamma triple gauge boson coupling parameters are studied using p-pbar
-> l nu gamma + X (l = e,mu) events at sqrt(s) = 1.96 TeV. The data were
collected with the DO detector from an integrated luminosity of 162 pb^{-1}
delivered by the Fermilab Tevatron Collider. The cross section times branching
fraction for p-pbar -> W(gamma) + X -> l nu gamma + X with E_T^{gamma} > 8 GeV
and Delta R_{l gamma} > 0.7 is 14.8 +/- 1.6 (stat) +/- 1.0 (syst) +/- 1.0 (lum)
pb. The one-dimensional 95% confidence level limits on anomalous couplings are
-0.88 < Delta kappa_{gamma} < 0.96 and -0.20 < lambda_{gamma} < 0.20.Comment: Submitted to Phys. Rev. D Rapid Communication
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt{s} = 1.96 TeV using Kinematic Characteristics of Lepton + Jets Events
We present a measurement of the top quark pair ttbar production cross section
in ppbar collisions at a center-of-mass energy of 1.96 TeV using 230 pb**{-1}
of data collected by the DO detector at the Fermilab Tevatron Collider. We
select events with one charged lepton (electron or muon), large missing
transverse energy, and at least four jets, and extract the ttbar content of the
sample based on the kinematic characteristics of the events. For a top quark
mass of 175 GeV, we measure sigma(ttbar) = 6.7 {+1.4-1.3} (stat) {+1.6- 1.1}
(syst) +/-0.4 (lumi) pb, in good agreement with the standard model prediction.Comment: submitted to Phys.Rev.Let
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Lepton + Jets Events with Lifetime b-tagging
We present a measurement of the top quark pair () production cross
section () in collisions at TeV
using 230 pb of data collected by the D0 experiment at the Fermilab
Tevatron Collider. We select events with one charged lepton (electron or muon),
missing transverse energy, and jets in the final state. We employ
lifetime-based b-jet identification techniques to further enhance the
purity of the selected sample. For a top quark mass of 175 GeV, we
measure pb, in
agreement with the standard model expectation.Comment: 7 pages, 2 figures, 3 tables Submitted to Phys.Rev.Let
Search for W' bosons decaying to an electron and a neutrino with the D0 detector
This Letter describes the search for a new heavy charged gauge boson W'
decaying into an electron and a neutrino. The data were collected with the D0
detector at the Fermilab Tevatron proton-antiproton Collider at a
center-of-mass energy of 1.96 TeV, and correspond to an integrated luminosity
of about 1 inverse femtobarn. Lacking any significant excess in the data in
comparison with known processes, an upper limit is set on the production cross
section times branching fraction, and a W' boson with mass below 1.00 TeV can
be excluded at the 95% C.L., assuming standard-model-like couplings to
fermions. This result significantly improves upon previous limits, and is the
most stringent to date.Comment: submitted to Phys. Rev. Let
Search for a scalar or vector particle decaying into Zgamma in ppbar collisions at sqrt(s) = 1.96 TeV
We present a search for a narrow scalar or vector resonance decaying into
Zgamma with a subsequent Z decay into a pair of electrons or muons. The data
for this search were collected with the D0 detector at the Fermilab Tevatron
ppbar collider at a center of mass energy sqrt(s) = 1.96 TeV. Using 1.1 (1.0)
fb-1 of data, we observe 49 (50) candidate events in the electron (muon)
channel, in good agreement with the standard model prediction. From the
combination of both channels, we derive 95% C.L. upper limits on the cross
section times branching fraction (sigma x B) into Zgamma. These limits range
from 0.19 (0.20) pb for a scalar (vector) resonance mass of 600 GeV/c^2 to 2.5
(3.1) pb for a mass of 140 GeV/c^2.Comment: Published by Phys. Lett.
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