4,942 research outputs found
Effect of intraoperative constant rate infusion of lidocaine on short-term survival of dogs with septic peritonitis: 75 cases (2007-2011)
OBJECTIVE To investigate whether intraoperative administration of a lidocaine infusion to dogs with septic peritonitis was associated with short-term (48 hours) survival after surgery. DESIGN Retrospective case series. ANIMALS 75 dogs with septic peritonitis. PROCEDURES Medical records of dogs with septic peritonitis that underwent laparotomy between January 2007 and December 2011 at the Royal Veterinary College were reviewed. Select variables during the preoperative, intraoperative, and postoperative periods and short-term survival after surgery were compared between dogs that received an opioid only (group O; n = 33) and dogs that received lidocaine (50 \u3bcg/kg/min [22.7 \u3bcg/kg/min], IV; group L; 42) in addition to an opioid during surgery. RESULTS The proportion of dogs that survived for 48 hours after surgery was significantly greater for group L (35/42) than for group O (20/33). Intraoperative infusion of lidocaine increased the odds of short-term survival (OR, 8.77; 95% CI, 1.94 to 39.57). No significant differences were observed between the 2 treatment groups for variables assessed during the preoperative and postoperative periods. During the intraoperative period, more dogs in group L received an IV bolus of a synthetic colloid than did dogs in group O, but the number of IV boluses administered was not associated with short-term survival. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that IV infusion of lidocaine might improve the short-term survival of dogs with septic peritonitis. Prospective clinical trials are necessary to determine the efficacy of lidocaine as a supportive treatment for dogs with septic peritonitis
Genetic diversity of wild-type measles viruses: implications for global measles elimination programs.
Wild-type measles viruses have been divided into distinct genetic groups according to the nucleotide sequences of their hemagglutinin and nucleoprotein genes. Most genetic groups have worldwide distribution; however, at least two of the groups appear to have a more limited circulation. To monitor the transmission pathways of measles virus, we observed the geographic distribution of genetic groups, as well as changes in them in a particular region over time. We found evidence of interruption of indigenous transmission of measles in the United States after 1993 and identified the sources of imported virus associated with cases and outbreaks after 1993. The pattern of measles genetic groups provided a means to describe measles outbreaks and assess the extent of virus circulation in a given area. We expect that molecular epidemiologic studies will become a powerful tool for evaluating strategies to control, eliminate, and eventually eradicate measles
Warm inflation and scalar perturbations of the metric
A second-order expansion for the quantum fluctuations of the matter field was
considered in the framework of the warm inflation scenario. The friction and
Hubble parameters were expended by means of a semiclassical approach. The
fluctuations of the Hubble parameter generates fluctuations of the metric.
These metric fluctuations produce an effective term of curvature. The power
spectrum for the metric fluctuations can be calculated on the infrared sector.Comment: 10 pages, no figures, to be published in General Rel. and Gravitatio
Experimental determination of a nonclassical Glauber-Sudarshan P function
A quantum state is nonclassical if its Glauber-Sudarshan P function fails to
be interpreted as a probability density. This quantity is often highly
singular, so that its reconstruction is a demanding task. Here we present the
experimental determination of a well-behaved P function showing negativities
for a single-photon-added thermal state. This is a direct visualization of the
original definition of nonclassicality. The method can be useful under
conditions for which many other signatures of nonclassicality would not
persist.Comment: 4 pages, 4 figure
Relationship between dielectric properties and critical behavior of the electric birefringence in binary liquid mixtures
We present experimental results on the critical exponent ψEKE describing the divergence of the Kerr constant of binary liquid mixtures near the critical consolute point. We show that the measured value of ψEKE agrees with the theoretical prediction only if the measurement is performed with a mixture of two liquids presenting a small mismatch in the dielectric constant, and that the measured ψEKE grows as the dielectric constant mismatch increases. Such findings are consistent with a recent model which assumes that the elongation of critical fluctations along the direction of the electric field can become so strong that fluctuations in the direction perpendicular to the electric field may cross over from Ising to mean-field behavior
Smectic ordering in liquid crystal - aerosil dispersions I. X-ray scattering
Comprehensive x-ray scattering studies have characterized the smectic
ordering of octylcyanobiphenyl (8CB) confined in the hydrogen-bonded silica
gels formed by aerosil dispersions. For all densities of aerosil and all
measurement temperatures, the correlations remain short range, demonstrating
that the disorder imposed by the gels destroys the nematic (N) to smectic-A
(SmA) transition. The smectic correlation function contains two distinct
contributions. The first has a form identical to that describing the critical
thermal fluctuations in pure 8CB near the N-SmA transition, and this term
displays a temperature dependence at high temperatures similar to that of the
pure liquid crystal. The second term, which is negligible at high temperatures
but dominates at low temperatures, has a shape given by the thermal term
squared and describes the static fluctuations due to random fields induced by
confinement in the gel. The correlation lengths appearing in the thermal and
disorder terms are the same and show strong variation with gel density at low
temperatures. The temperature dependence of the amplitude of the static
fluctuations further suggests that nematic susceptibility become suppressed
with increasing quenched disorder. The results overall are well described by a
mapping of the liquid crystal-aerosil system into a three dimensional XY model
in a random field with disorder strength varying linearly with the aerosil
density.Comment: 14 pages, 13 figure
Hydrogen-bonded Silica Gels Dispersed in a Smectic Liquid Crystal: A Random Field XY System
The effect on the nematic to smectic-A transition in octylcyanobiphenyl (8CB)
due to dispersions of hydrogen-bonded silica (aerosil) particles is
characterized with high-resolution x-ray scattering. The particles form weak
gels in 8CB creating a quenched disorder that replaces the transition with the
growth of short range smectic correlations. The correlations include thermal
critical fluctuations that dominate at high temperatures and a second
contribution that quantitatively matches the static fluctuations of a random
field system and becomes important at low temperatures.Comment: 10 pages, 4 postscript figures as separate file
Smectic ordering in liquid crystal - aerosil dispersions II. Scaling analysis
Liquid crystals offer many unique opportunities to study various phase
transitions with continuous symmetry in the presence of quenched random
disorder (QRD). The QRD arises from the presence of porous solids in the form
of a random gel network. Experimental and theoretical work support the view
that for fixed (static) inclusions, quasi-long-range smectic order is destroyed
for arbitrarily small volume fractions of the solid. However, the presence of
porous solids indicates that finite-size effects could play some role in
limiting long-range order. In an earlier work, the nematic - smectic-A
transition region of octylcyanobiphenyl (8CB) and silica aerosils was
investigated calorimetrically. A detailed x-ray study of this system is
presented in the preceding Paper I, which indicates that pseudo-critical
scaling behavior is observed. In the present paper, the role of finite-size
scaling and two-scale universality aspects of the 8CB+aerosil system are
presented and the dependence of the QRD strength on the aerosil density is
discussed.Comment: 14 pages, 10 figures, 1 table. Companion paper to "Smectic ordering
in liquid crystal - aerosil dispersions I. X-ray scattering" by R.L. Leheny,
S. Park, R.J. Birgeneau, J.-L. Gallani, C.W. Garland, and G.S. Iannacchion
Gravity in 2+1 dimensions as a Riemann-Hilbert problem
In this paper we consider 2+1-dimensional gravity coupled to N
point-particles. We introduce a gauge in which the - and
-components of the dreibein field become holomorphic and
anti-holomorphic respectively. As a result we can restrict ourselves to the
complex plane. Next we show that solving the dreibein-field: is
equivalent to solving the Riemann-Hilbert problem for the group . We
give the explicit solution for 2 particles in terms of hypergeometric
functions. In the N-particle case we give a representation in terms of
conformal field theory. The dreibeins are expressed as correlators of 2 free
fermion fields and twistoperators at the position of the particles.Comment: 32 pages Latex, 4 figures (uuencoded
About the strength of correlation effects in the electronic structure of iron
The strength of electronic correlation effects in the spin-dependent
electronic structure of ferromagnetic bcc Fe(110) has been investigated by
means of spin and angle-resolved photoemission spectroscopy. The experimental
results are compared to theoretical calculations within the three-body
scattering approximation and within the dynamical mean-field theory, together
with one-step model calculations of the photoemission process. This comparison
indicates that the present state of the art many-body calculations, although
improving the description of correlation effects in Fe, give too small mass
renormalizations and scattering rates thus demanding more refined many-body
theories including non-local fluctuations.Comment: 4 pages, 4 figure
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