107 research outputs found
MAC-AWAKE OF ISOFLURANE, ENFLURANE AND HALOTHANE EVALUATED BY SLOW AND FAST ALVEOLAR WASHOUT
End-tidal anaesthetic concentrations at first eye opening in response to a verbal command during recovery from anaesthesia (MAC-awake), were measured for isoflurane (n = 16), enflurane (n = 16) and halothane (n = 14). MAC-awake was measured during either slow or fast alveolar washout. Slow washout was obtained by decreasing anaesthetic concentrations in predetermined steps of 15min, assuming equilibration between brain and alveolar partial pressures. Fast alveolar washout was obtained by discontinuation of the inhalation anaesthetic, which had been maintained at 1 MAC for at least 15 min. Mean MAC-awake obtained with slow alveolar washout was similar for isoflurane (0.25 (SD 0.03) MAC), and enflurane (0.27 (0.04) MAC) and significantly greater than values obtained by fast alveolar washout (isoflurane: 0.19 (0.03) MAC; enflurane: 0.20 (0.03) MAC). The MAC-awake of isoflurane and enflurane was significantly less than that of halothane, which was 0.59 (0.10) MAC as evaluated by the slow and 0.50 (0.05) MAC as evaluated by the fast alveolar washout method. Recovery time from anaesthesia with fast alveolar washout was 8.8 (4.0) min for halothane, which was not different from isoflurane (15 (2.5) min), but significantly shorter than for enflurane (22 (10) min), reflecting differences in the anaesthetic concentration gradient between MAC and MAC-awake values. These data do not support the hypothesis of a uniform ratio between MAC and MAC-awake value
Coherent States in Null-Plane Q.E.D
Light front field theories are known to have the usual infra-red divergences
of the equal time theories, as wellas new `spurious' infra-red divergences. The
formar kind of IR divergences are usually treated by giving a small mass to the
gauge particle. An alternative method to deal with these divergences is to
calculate the transition matrix elements in a coherent state basis. In this
paper we present, as a model calculation the lowest order correction to the
three point vertex in QED using a coherent state basis in the light cone
formalism. The relevant transition matrix element is shown to be free of the
true IR divergences up to .Comment: 20 pages and two figures, REVTEX, ITP-SB-93-7
End-point singularities of Feynman graphs on the light cone
We show that some Lorentz components of the Feynman integrals calculated in
terms of the light-cone variables may contain end-point singularities which
originate from the contribution of the big-circle integral in the complex k_
plane. These singularities appear in various types of diagrams (two-point
functions, three-point functions, etc) and provide the covariance of the
Feynman integrals on the light-cone. We propose a procedure for calculating
Feynman integrals which guarantees that the end-point singularities do not
appear in the light-cone representations of the invariant amplitudes.Comment: final version to appear in PLB; few references adde
Garden waste management: Process and cost
Garden waste is a blend of organic such as flowers, grass clippings, branches and wood and non-organic such as soil that is produced during the maintenance of public parks and small gardens.Garden waste generation and constantly changing depending on location and season.In Malaysia, garden waste management managed by Municipal Council as well as private companies.This study will be obtained qualitatively by seeking information through interviews with company Enviroment EIdaman Sdn Bhdwhich manages garden waste all areas of Kedah.Therefore, this study was able to identify the processes that are carried out to manage the garden waste as well as evaluate the cost of each of these processes. Expected result may show the cost of process garden waste are high
Path Integral Approach to Two-Dimensional QCD in the Light-Front
Two-dimensional quantum cromodynamics in the light-front frame is studied
following hamiltonian methods. The theory is quantized using the path integral
formalism and an effective theory similar to the Nambu-Jona Lasinio model is
obtained. Confinement in two dimensions is derived analyzing directly the
constraints in the path integral.Comment: 13pp, Plain-TeX, Si-93-10, IF-UFRJ-93-13, USM-TH-6
Results of open reduction internal fixation versus percutaneous iliosacral screw fixation for unstable pelvic ring injuries: retrospective study of 36 patients.
Surgical stabilization of posterior pelvic ring fractures can be achieved by closed reduction and percutaneous fixation (CRPF) or by open reduction and internal fixation (ORIF). The aim of the present study is to compare the clinical results of both methods.
Medical records of 36 patients consecutively operated for unstable pelvic ring injuries were retrospectively reviewed. We compared 22 patients treated with CRPF versus 14 patients stabilized by using ORIF between 2007 and 2017. The Majeed and Pohlemann scores were used to evaluate postoperative functional outcomes. Complications like blood loss, infection rate, Neurological injury, the operative time and the length of hospital stay were analyzed.
The median Majeed pelvic score was 87 points for the CRPF technique compared with 69 points for the ORIF technique. The median Pohlemann score, operative time and length of hospitalization were similar between the two groups. The median blood loss for the CRPF technique was 300 ml compared to 500 ml for the ORIF technique. CRPF and ORIF procedure had each one neurological lesion. There was one case of infection in the ORIF group and none in the CRPF group. No measurements except for the blood loss have reached the significance threshold.
The CRPF technique shows a clear decrease in blood loss. There was no statistically significant difference in the functional results, infection rate, neurological injury, operative time and hospital stay between both techniques
Glueball spectrum in a (1+1)-dimensional model for QCD
We consider (1+1)-dimensional QCD coupled to scalars in the adjoint
representation of the gauge group SU(). This model results from dimensional
reduction of the (2+1)-dimensional pure glue theory. In the large-N limit we
study the spectrum of glueballs numerically, using the discretized \lcq. We
find a discrete spectrum of bound states, with the density of levels growing
approximately exponentially with the mass. A few low-lying states are very
close to being eigenstates of the parton number, and their masses can be
accurately calculated by truncated diagonalizations.Comment: 17 pages, uses phyzzx and table.tex, 5 figures available upon request
from [email protected]
Chiral Symmetry in Light-front QCD
The definition of chiral transformations in light-front field theory is very
different from the conventional form in equal-time formalism. We study the
consistency of chiral transformations and chiral symmetry in light-front QCD
and derive a complete new light-front axial-vector current for QCD. The
breaking of chiral symmetry in light-front QCD is only associated with helicity
flip interaction between quarks and gluons. Remarkably, the new axial-vector
current does not contain the pion pole part so that the associate chiral charge
smoothly describes pion transitions for various hadronic processes.Comment: 15 pages, no figure, JHEP style, added reference and corrected typos
and some changed conten
Nonperturbative renormalization in a scalar model within Light-Front Dynamics
Within the covariant formulation of Light-Front Dynamics, in a scalar model
with the interaction Hamiltonian , we calculate
nonperturbatively the renormalized state vector of a scalar "nucleon" in a
truncated Fock space containing the , and sectors. The
model gives a simple example of non-perturbative renormalization which is
carried out numerically. Though the mass renormalization diverges
logarithmically with the cutoff , the Fock components of the "physical"
nucleon are stable when .Comment: 22 pages, 5 figure
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