282 research outputs found
Stochastic Variational Search for H
A four-body calculation of the bound state, $^{\
4}_{\Lambda\Lambda}NN\Lambda N\Lambda\Lambda\Lambda\Lambda_\Lambda^3{H}+\Lambda\Lambda\LambdaB_{\Lambda\Lambda}(^{6}_{\Lambda\Lambda}{He})d\Lambda\Lambda$ model in the Letter.Comment: Corrected typos, added addtional calculations regarding a truncated
to l=0 interaction model, 4 pages, 3 figure
The (K-,p) reaction on nuclei with in-flight kaons
We perform a theoretical study of the spectrum of protons with kinetic
energies of around 600 MeV, emitted following the interaction of 1 GeV/c kaons
with nuclei. A recent experimental analysis of this (K-,p) reaction on 12C,
based on the dominant quasielastic process, has suggested a deeply attractive
kaon nucleus potential. Our Monte Carlo simulation considers, in addition, the
one-and two-nucleon K- absorption processes producing hyperons that decay into
\pi N pairs. We find that this kaon in-flight reaction is not well suited to
determine the kaon optical potential due, essentially, to the limited
sensitivity of the cross section to its strength, but also to unavoidable
uncertainties from the coincidence requirement applied in the experiment. A
shallow kaon nucleus optical potential obtained in chiral models is perfectly
compatible with the observed spectrum.Comment: To appear in the proceedings of the 10th International Conference on
Hypernuclear and Strange Particle Physics, Tokai, Ibaraki (Japan), 14-18
September, 200
Glomerulonefrite pós-infecciosa hipocomplementêmica aguda como complicação de celulite orbitária relacionada aos seios paranasais: relato de caso
Group A beta-hemolytic streptococcus is the most common agent implicated in post-infectious acute glomerulonephritis. We report a case of acute poststreptococcal glomerulonephritis associated with sinus-related orbital abscess in an 11-year-old boy treated with surgical drainage and intravenous ceftriaxone and clindamycin. Twelve days after supportive measures, renal function was normalized. We also discuss this potentially severe nonsuppurative complication of orbital cellulitis caused by group A beta-hemolytic streptococcus.Os estreptococos beta-hemolÃticos do grupo A são os agentes mais comumente envolvidos na glomerulonefrite aguda pós-infecciosa. Relatamos um caso de glomerulonefrite pós-estreptocócica aguda associada a um abscesso orbitário secundário à sinusite, em menino de 11 anos de idade, o qual foi tratado com ceftriaxona e clindamicina endovenosas e drenagem cirúrgica. Doze dias após tratamento de suporte, a função renal se normalizou. Também discutimos a importância desta grave e potencial complicação não supurativa das celulites orbitárias causadas pelos estreptococos beta-hemolÃticos do grupo A
Upper lid crease approach for margin rotation in trachomatous cicatricial entropion without external sutures
ABSTRACT Purpose: To describe the use of a lid crease incision for upper eyelid margin rotation in cicatricial entropion combining internal traction on the anterior lamella, tarsotomy, and tarsal overlap without external sutures. Methods: Surgical description: The main steps of the procedure consisted of exposure of the entire tarsal plate up to the eyelashes followed by tarsotomy through the conjunctiva. A double-armed 6.0 polyglactin suture was then passed through the distal tarsal fragment to the marginal section of the orbicularis oculi muscle. As the sutures were tied, the distal tarsus advanced over the marginal section, and traction was exerted on the marginal strip of the orbicularis muscle. There were no bolsters or external knots. The pretarsal skin-muscle flap was closed with a 6.0 plain gut suture. Results: We used this procedure at a tertiary hospital in Saudi Arabia from 2013 to 2014. Sixty upper lids of 40 patients (23 women and 17 men) were operated on, with an age range of 44-99 years [mean ± standard deviation (SD) = 70.9 ± 13.01 years]. Bilateral surgery was performed on 21 patients. Follow-up ranged from 1 to 12 months (mean 3.0 ± 2.71 months). Forty percent of the patients (24 lids) had more than 3 months' follow-up. The postoperative lid margin position was good in all cases. Trichiasis (two lashes) was observed in only one patient with unilateral entropion on the medial aspect of the operated lid. Conclusions: The upper lid margin can be effectively rotated through a lid crease incision with internal sutures. The technique combines the main mechanisms of the Wies and Trabut approaches and avoids the use of bolsters or external sutures, which require a second consultation to be removed. Some other lid problems, such as ptosis, retraction, or dermatochalasis, can be concomitantly addressed during the procedure
nuclear bound states in a dynamical model
A comprehensive data base of K- atom level shifts and widths is re-analyzed
in order to study the density dependence of the Kbar-nuclear optical potential.
Significant departure from a t*rho form is found only for nuclear densities
about and less than 20% of nuclear-matter density, and extrapolation to
nuclear-matter density yields an attractive potential, about 170 MeV deep.
Partial restoration of chiral symmetry compatible with pionic atoms and
low-energy pion-nuclear data plays no role at the relevant low-density regime,
but this effect is not ruled out at high densities. Kbar-nuclear bound states
are generated across the periodic table self consistently, using a relativistic
mean-field model Lagrangian which couples the Kbar to the scalar and vector
meson fields mediating the nuclear interactions. The reduced phase space
available for Kbar absorption from these bound states is taken into account by
adding an energy-dependent imaginary term which underlies the corresponding
Kbar-nuclear level widths, with a strength required by fits to the atomic data.
Substantial polarization of the core nucleus is found for light nuclei, and the
binding energies and widths calculated in this dynamical model differ
appreciably from those calculated for a static nucleus. A wide range of binding
energies is spanned by varying the Kbar couplings to the meson fields. Our
calculations provide a lower limit of Gamma(Kbar) = 50 +/- 10 MeV on the width
of nuclear bound states for Kbar binding energy in the range B(Kbar) = 100 -
200 MeV. Comments are made on the interpretation of the FINUDA experiment at
DAFNE, Frascati, which claimed evidence for deeply bound (K- pp) states in
light nuclei.Comment: Added 2 figures and discussion. Version accepted for publication in
NP
Abscesso orbitário secundário à dacriocistite aguda: relato de caso
Acute dacryocystitis usually induces preseptal infection. In rare instances the infection that is confined to the lacrimal sac can extend to the orbital contents resulting in orbital cellulitis. We present a case of intraconal abscess secondary to acute dacryocystitis and review the literature of orbital cellulitis resulting from acute lacrimal sac infection.A dacriocistite aguda comumente evolui para infecção pré-septal. Raramente a infecção localizada no saco lacrimal pode estender-se ao conteúdo orbitário resultando em celulite orbitária. Apresentamos um caso de abscesso orbitário intraconal secundário à dacriocistite aguda e uma revisão de literatura de celulite orbitária causada por infecção aguda do saco lacrimal
A search for deeply bound kaonic nuclear states
We have measured proton and neutron energy spectra by stopping negative kaons
on liquid helium4. Two distinct peak structures were found on both spectra,
which were assigned to the formation of new kinds of strange stribaryons. In
this paper, we summarize both results.Comment: 7 pages, 3 figures, HYP2003 conference proceeding
Latest results for the antikaon-nucleon optical potential
The key question of this letter is whether the K-nucleus optical potential is
deep, as it is prefered by the phenomenological fits to kaonic atoms data, or
shallow, as it comes out from unitary chiral model calculations. The current
experimental situation is reviewed.Comment: 3 pages, 1 figure. Presented at the 21st European Conference on the
Few-Body problems in Physics (EFB21), Salamanca, Spain, August 29 - September
3, 201
Recent developments in chiral dynamics of hadrons and hadrons in a nuclear medium
In this talk I present recent developments in chiral dynamics of hadrons and
hadrons in a medium addressing the following points: interaction of the octet
of pseudoscalar mesons with the octet of baryons of the nucleon, showing recent
experimental evidence on the existence of two states, the
interaction of the octet of pseudoscalar mesons with the decuplet of baryons of
the , with particular emphasis on the resonance,
dynamically generated by this interaction. Then I review the interaction of
kaons in a nuclear medium and briefly discuss the situation around the claims
of deeply bound states in nuclei. The large renormalization of the
in the nuclear medium is shown as another example of successful
application of the chiral unitary techniques.Comment: Talk at the Fifth International Conference on Perspectives in
Hadronic Physics: Particle-Nucleus and Nucleus-Nucleus Scattering at
Relativistic Energies, Trieste, May 200
Chirally motivated K^- nuclear potentials
In-medium subthreshold KbarN scattering amplitudes calculated within a
chirally motivated meson-baryon coupled-channel model are used self
consistently to confront K^- atom data across the periodic table. Substantially
deeper K^- nuclear potentials are obtained compared to the shallow potentials
derived in some approaches from threshold amplitudes, with Re V_{chiral} =
-(85+/-5) MeV at nuclear matter density. When KbarNN contributions are
incorporated phenomenologically, a very deep K^- nuclear potential results, Re
V_{chiral+phen.} = -(180+/-5) MeV, in agreement with density dependent
potentials obtained in purely phenomenological fits to the data. Self
consistent dynamical calculations of K^- nuclear quasibound states are reported
and discussed.Comment: extended discussion, unchanged results and conclusions, accepted by
PL
- …