627 research outputs found
Two-loop self-energy correction in high-Z hydrogen-like ions
A complete evaluation of the two-loop self-energy diagrams to all orders in
Z\alpha is presented for the ground state of H-like ions with Z\ge 40.Comment: RevTeX, 5 figures, 1 tabl
INTERACTIONS OF THE COMPLEMENT SYSTEM WITH ENDOTOXIC LIPOPOLYSACCHARIDE : GENERATION OF A FACTOR CHEMOTACTIC FOR POLYMORPHONUCLEAR LEUKOCYTES
Endotoxic lipopolysaccharide has recently been shown to fix large amounts of the complement components related to the biologic activities mediated by that system. The present study sought to determine whether the generation of chemotactic factor by endotoxin in serum was dependent upon complement system activation. Preheating serum, incubating at 0°C, or incubating in the presence of EDTA, all prevented chemotactic factor generation as well as complement fixation by endotoxin. "Endotoxoids" deficient in complement-firing activity were also deficient in chemotactic factor generation. Chemotactic factor could not be generated by endotoxin in sera of mice congenitally deficient in the C'S component of complement, while chemotactic factor was generated by endotoxin in the sera of coisogenic mice with normal complement levels for that species. The chemotactic factor induced by endotoxin was heat stable and nondialyzable. Molecular sieve chromatography and sucrose density gradient ultracentrifugation demonstrated that the chemotactic factor was a relatively low molecular weight product (15,000â30,000) and as such different from previously scribed C' system-derived chemotactic factors. These experiments demonstrate that generation of chemotactic factor by endotoxin in serum is dependent upon C' system activation involving at least C'5. Furthermore, the relatively low molecular weight of this factor suggests that it might be derived from activation of a single complement component rather than from complexing of multiple complement components
Evaluation of the self-energy correction to the g-factor of S states in H-like ions
A detailed description of the numerical procedure is presented for the
evaluation of the one-loop self-energy correction to the -factor of an
electron in the and states in H-like ions to all orders in .Comment: Final version, December 30, 200
Relativistic dynamical polarizability of hydrogen-like atoms
Using the operator representation of the Dirac Coulomb Green function the
analytical method in perturbation theory is employed in obtaining solutions of
the Dirac equation for a hydrogen-like atom in a time-dependent electric field.
The relativistic dynamical polarizability of hydrogen-like atoms is calculated
and analysed.Comment: 15 pages, 3 figures (not included, but hard copies are available upon
request
Loop-after-loop contribution to the second-order Lamb shift in hydrogenlike low-Z atoms
We present a numerical evaluation of the loop-after-loop contribution to the
second-order self-energy for the ground state of hydrogenlike atoms with low
nuclear charge numbers Z. The calculation is carried out in the Fried-Yennie
gauge and without an expansion in Z \alpha. Our calculation confirms the
results of Mallampalli and Sapirstein and disagrees with the calculation by
Goidenko and coworkers. A discrepancy between different calculations is
investigated. An accurate fitting of the numerical results provides a detailed
comparison with analytic calculations based on an expansion in the parameter Z
\alpha. We confirm the analytic results of order \alpha^2 (Z\alpha)^5 but
disagree with Karshenboim's calculation of the \alpha^2 (Z \alpha)^6 \ln^3(Z
\alpha)^{-2} contribution.Comment: RevTex, 19 pages, 4 figure
Phase Structure and Nonperturbative States in Three-Dimensional Adjoint Higgs Model
The thermodynamics of 3d adjoint Higgs model is considered. We study the
properties of the Polyakov loop correlators and the critical behavior at the
deconfinement phase transition. Our main tool is a reduction to the 2d
sine-Gordon model. The Polyakov loops appear to be connected with the soliton
operators in it. The known exact results in the sine-Gordon theory allow us to
study in detail the temperature dependence of the string tension, as well as to
get some information about a nonperturbative dynamics in the confinement phase.
We also consider the symmetry restoration at high temperature which makes it
possible to construct the phase diagram of the model completely.Comment: 15pp., Revtex; 4 figures; replaced by a version to be published in
Phys. Rev.
Endoscopic transnasal transpterygopalatine fossa approach to the lateral recess of the sphenoid sinus
Q1Q1528-532Objectives Lesions affecting the lateral recess of the sphenoid sinus are rarely discussed in the literature as a separate entity. This region is difficult to visualize and manipulate through the transnasal routes, especially when extensive pneumatization is present. External approaches to this area involve extensive surgery and are associated with significant morbidity. The objectives of this study are to present our experience with the endoscopic transpterygopalatine fossa approach as a method for exposing and manipulating lesions of the lateral recess of the sphenoid and to illustrate the detailed surgical steps of the procedure.
Study Design Retrospective review.
Methods Clinical charts of patients who had lesions originating from or extending into the lateral recess of the sphenoid sinus and who were treated at our institutions from September 1995 to June 2002 were retrospectively reviewed. All these patients were managed by the endoscopic transpterygopalatine fossa approach.
Results Twelve patients (7 males and 5 females) were included in the study. Lesions included seven cerebrospinal fluid (CSF) leaks and five tumors. One patient with squamous cell carcinoma (SCC) of the sphenoid died of his disease. All CSF leaks were successfully repaired, and benign tumors were removed with good local control through the followâup period.
Conclusion The endoscopic transpterygopalatine fossa approach is an excellent approach for dealing with lesions of the sphenoid lateral recess
Multibaryons as Symmetric Multiskyrmions
We study non-adiabatic corrections to multibaryon systems within the bound
state approach to the SU(3) Skyrme model. We use approximate ansatze for the
static background fields based on rational maps which have the same symmetries
of the exact solutions. To determine the explicit form of the collective
Hamiltonians and wave functions we only make use of these symmetries. Thus, the
expressions obtained are also valid in the exact case. On the other hand, the
inertia parameters and hyperfine splitting constants we calculate do depend on
the detailed form of the ansatze and are, therefore, approximate. Using these
values we compute the low lying spectra of multibaryons with B <= 9 and
strangeness 0, -1 and -B. Finally, we show that the non-adiabatic corrections
do not affect the stability of the tetralambda and heptalambda found in a
previous work.Comment: 17 pages, RevTeX, no figure
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