2,681 research outputs found
Management of skin-sparing mastectomy: Results of a survey of German Hospitals
Background: The aim of this study was to evaluate the current management of skin-sparing mastectomy in German hospitals and to determine its oncologic safety. For this purpose, 100 surgeons were surveyed regarding their use of skin-sparing mastectomy. Results: Almost all surveyed hospitals performed skin-sparing mastectomy. Most of them believe that the recurrence rate is equal to that of conventional mastectomy. 95% regard inflammatory cancer as a contraindication to skin-sparing surgery. Most of the hospitals thin out the skin without leaving any macroscopic glandular tissue behind, and 73% leave the nipple-areola complex (NAC) on the basis of frozen sections. Volume replacement is most commonly done with latissimus dorsi muscle flaps and pedicled TRAM flaps. In 76% of the surveyed hospitals, reconstruction after mastectomy is performed by the gynecological department. Conclusion: Skin-sparing mastectomy is considered to be the best cosmetic option for breast reconstruction in selected breast cancer patients. At present, statistical proof of its oncologic safety is lacking. The surgical techniques used for skin-sparing mastectomy have not yet been standardized. In order to achieve standardization, careful discussion-making and evaluation remain important
Theory of Optical Tweezers
We derive a partial-wave (Mie) expansion of the axial force exerted on a
transparent sphere by a laser beam focused through a high numerical aperture
objective. The results hold throughout the range of interest for practical
applications. The ray optics limit is shown to follow from the Mie expansion by
size averaging. Numerical plots show large deviations from ray optics near the
focal region and oscillatory behavior (explained in terms of a simple
interferometer picture) of the force as a function of the size parameter.
Available experimental data favor the present model over previous ones.Comment: 4 pages, 3 figure
Transverse Pressure and Strangeness Dynamics in Relativistic Heavy Ion Reactions
Transverse hadron spectra from proton-proton, proton-nucleus and
nucleus-nucleus collisions from 2 AGeV to 21.3 ATeV are investigated within two
independent transport approaches (HSD and UrQMD). For central Au+Au (Pb+Pb)
collisions at energies above 5 AGeV, the measured
transverse mass spectra have a larger inverse slope parameter than expected
from the default calculations. The additional pressure - as suggested by
lattice QCD calculations at finite quark chemical potential and
temperature - might be generated by strong interactions in the early
pre-hadronic/partonic phase of central Au+Au (Pb+Pb) collisions. This is
supported by a non-monotonic energy dependence of in the present
transport model.Comment: Proceedings of Strange Quark Matter 200
The effects of meson mixing on dilepton spectra
The effect of scalar and vector meson mixing on the dilepton radiation from
hot and dense hadronic matter is estimated in different isospin channels. In
particular, we study the effect of - and mixing and
calculate the corresponding rates. Effects are found to be significant compared
to standard - and - annihilations. While the mixing in
the isoscalar channel mostly gives a contribution in the invariant mass range
between the two-pion threshold and the peak, the isovector channel
mixing induces an additional peak just below that of the .
Experimentally, the dilepton signals from - mixing seem to be more
tractable than those from - mixing.Comment: 10 pages, 9 figure
Strange Hadron Resonances and QGP Freeze-out
We describe how the abundance and distribution of hyperon resonances can be
used to probe freeze-out conditions. We demonstrate that resonance yields allow
us to measure the time scales of chemical and thermal freeze-outs. This should
permit a direct differentiation between the explosive sudden, and staged
adiabatic freeze-out scenarios.Comment: 8 pages including 4 figures, in Proceedings of Strange Quark Matter
2001, Frankfurt, submitted to J. Phys. G version 2: refernces
corrected/added, numercial corrections in figures 2,3,
Interferometry signatures for QCD first-order phase transition in heavy ion collisions at GSI-FAIR energies
Using the technique of quantum transport of the interfering pair we examine
the Hanbury-Brown-Twiss (HBT) interferometry signatures for the
particle-emitting sources of pions and kaons produced in the heavy ion
collisions at GSI-FAIR energies. The evolution of the sources is described by
relativistic hydrodynamics with the system equation of state of the first-order
phase transition from quark-gluon plasma (QGP) to hadronic matter. We use
quantum probability amplitudes in a path-integral formalism to calculate the
two-particle correlation functions, where the effects of particle decay and
multiple scattering are taken into consideration. We find that the HBT radii of
kaons are smaller than those of pions for the same initial conditions. Both the
HBT radii of pions and kaons increase with the system initial energy density.
The HBT lifetimes of the pion and kaon sources are sensitive to the initial
energy density. They are significantly prolonged when the initial energy
density is tuned to the phase boundary between the QGP and mixed phase. This
prolongations of the HBT lifetimes of pions and kaons may likely be observed in
the heavy ion collisions with an incident energy in the GSI-FAIR energy range.Comment: 16 pages, 4 figure
Design of the Pluto Event Generator
We present the design of the simulation package Pluto, aimed at the study of
hadronic interactions at SIS and FAIR energies. Its main mission is to offer a
modular framework with an object-oriented structure, thereby making additions
such as new particles, decays of resonances, new models up to modules for
entire changes easily applicable. Overall consistency is ensured by a plugin-
and distribution manager. Particular features are the support of a modular
structure for physics process descriptions, and the possibility to access the
particle stream for on-line modifications. Additional configuration and
self-made classes can be attached by the user without re-compiling the package,
which makes Pluto extremely configurable.Comment: Presented at the 17th International Conference on Computing in High
Energy and Nuclear Physic
Design of the Pluto Event Generator
We present the design of the simulation package Pluto, aimed at the study of
hadronic interactions at SIS and FAIR energies. Its main mission is to offer a
modular framework with an object-oriented structure, thereby making additions
such as new particles, decays of resonances, new models up to modules for
entire changes easily applicable. Overall consistency is ensured by a plugin-
and distribution manager. Particular features are the support of a modular
structure for physics process descriptions, and the possibility to access the
particle stream for on-line modifications. Additional configuration and
self-made classes can be attached by the user without re-compiling the package,
which makes Pluto extremely configurable.Comment: Presented at the 17th International Conference on Computing in High
Energy and Nuclear Physic
Design of the Pluto Event Generator
We present the design of the simulation package Pluto, aimed at the study of
hadronic interactions at SIS and FAIR energies. Its main mission is to offer a
modular framework with an object-oriented structure, thereby making additions
such as new particles, decays of resonances, new models up to modules for
entire changes easily applicable. Overall consistency is ensured by a plugin-
and distribution manager. Particular features are the support of a modular
structure for physics process descriptions, and the possibility to access the
particle stream for on-line modifications. Additional configuration and
self-made classes can be attached by the user without re-compiling the package,
which makes Pluto extremely configurable.Comment: Presented at the 17th International Conference on Computing in High
Energy and Nuclear Physic
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