452 research outputs found
Serum Levels of Soluble IL-2R, CD4 and CD8 in Chronic Active HCV Positive Hepatitis
The aim of the present study was to compare serum levels of soluble
forms of interleukin-2 receptor, CD4 and CD8, released by
lymphocytes during activation ofthe immune system, in patients with
histologically verified chronic active hepatitis associated to
hepatitis C virus infection, with those in healthy subjects.
Significantly higher levels of soluble IL-2R and soluble CD8 were
found in patients with chronic active hepatitis compared with
controls. In contrast no difference was found for soluble CD4 values
in the two groups. No correlations were found for both sIL-2R and
sCD8 and these two molecules with other parameters of liver
function. These results indicate that in these patients there is a
general activation of the immune system, but the lack of correlation
with parameters of liver function strengthens the suggestion that
this activation does not play a role in the pathogenesis of chronic
type C hepatitis
Strong enhancement of extremely energetic proton production in central heavy ion collisions at intermediate energy
The energetic proton emission has been investigated as a function of the
reaction centrality for the system 58Ni + 58Ni at 30A MeV. Extremely energetic
protons (EpNN > 130 MeV) were measured and their multiplicity is found to
increase almost quadratically with the number of participant nucleons thus
indicating the onset of a mechanism beyond one and two-body dynamics.Comment: 5 pages, 2 figures, submitted to Physical Review Letter
Atmospheric MUons from PArametric formulas: a fast GEnerator for neutrino telescopes (MUPAGE)
Neutrino telescopes will open, in the next years, new opportunities in
observational high energy astrophysics. For these experiments, atmospheric
muons from primary cosmic ray interactions in the atmosphere play an important
role, because they provide the most abundant source of events for calibration
and test. On the other side, they represent the major background source.
In this paper a fast Monte Carlo generator (called MUPAGE) of bundles of
atmospheric muons for underwater/ice neutrino telescopes is presented. MUPAGE
is based on parametric formulas [APP25(2006)1] obtained from a full Monte Carlo
simulation of cosmic ray showers generating muons in bundle, which are
propagated down to 5 km w.e. It produces the event kinematics on the surface of
a user-defined virtual cylinder, surrounding the detector. The multiplicity of
the muons in the bundle, the muon spatial distribution and energy spectrum are
simulated according to a specific model of primary cosmic ray flux, with
constraints from measurements of the muon flux with underground experiments. As
an example of the application, the result of the generation of events on a
cylindrical surface of 3 km^2 at a depth of 2450 m of water is presented.Comment: 20 pages, 4 figure
High-Energy Neutrino Astronomy
Kilometer-scale neutrino detectors such as IceCube are discovery instruments
covering nuclear and particle physics, cosmology and astronomy. Examples of
their multidisciplinary missions include the search for the particle nature of
dark matter and for additional small dimensions of space. In the end, their
conceptual design is very much anchored to the observational fact that Nature
accelerates protons and photons to energies in excess of and
eV, respectively. The cosmic ray connection sets the scale of cosmic
neutrino fluxes. In this context, we discuss the first results of the completed
AMANDA detector and the reach of its extension, IceCube. Similar experiments
are under construction in the Mediterranean. Neutrino astronomy is also
expanding in new directions with efforts to detect air showers, acoustic and
radio signals initiated by super-EeV neutrinos.Comment: 9 pages, Latex2e, uses ws-procs975x65standard.sty (included), 4
postscript figures. To appear in Proceedings of Thinking, Observing, and
Mining the Universe, Sorrento, Italy, September 200
Contemporary presence of dynamical and statistical production of intermediate mass fragments in midperipheral Ni+Ni collisions at 30 MeV/nucleon
The reaction at 30 MeV/nucleon has been experimentally
investigated at the Superconducting Cyclotron of the INFN Laboratori Nazionali
del Sud. In midperipheral collisions the production of massive fragments
(4Z12), consistent with the statistical fragmentation of the
projectile-like residue and the dynamical formation of a neck, joining
projectile-like and target-like residues, has been observed. The fragments
coming from these different processes differ both in charge distribution and
isotopic composition. In particular it is shown that these mechanisms leading
to fragment production act contemporarily inside the same event.Comment: 9 pages, minor correction
Size and asymmetry of the reaction entrance channel: influence on the probability of neck production
The results of experiments performed to investigate the Ni+Al, Ni+Ni, Ni+Ag
reactions at 30 MeV/nucleon are presented. From the study of dissipative
midperipheral collisions, it has been possible to detect events in which
Intermediate Mass Fragments (IMF) production takes place. The decay of a
quasi-projectile has been identified; its excitation energy leads to a
multifragmentation totally described in terms of a statistical disassembly of a
thermalized system (T4 MeV, E4 MeV/nucleon). Moreover, for
the systems Ni+Ni, Ni+Ag, in the same nuclear reaction, a source with velocity
intermediate between that of the quasi-projectile and that of the quasi-target,
emitting IMF, is observed. The fragments produced by this source are more
neutron rich than the average matter of the overall system, and have a charge
distribution different, with respect to those statistically emitted from the
quasi-projectile. The above features can be considered as a signature of the
dynamical origin of the midvelocity emission. The results of this analysis show
that IMF can be produced via different mechanisms simultaneously present within
the same collision. Moreover, once fixed the characteristics of the
quasi-projectile in the three considered reactions (in size, excitation energy
and temperature), one observes that the probability of a partner IMF production
via dynamical mechanism has a threshold (not present in the Ni+Al case) and
increases with the size of the target nucleus.Comment: 16 pages, 7 figures, accepted for publication on Nuclear Physics
Detection potential to point-like neutrino sources with the NEMO-km3 telescope
The NEMO Collaboration is conducting an R&D activity towards the construction
of a Mediterranean km3 neutrino telescope. In this work, we present the results
of Monte Carlo simulation studies on the capability of the proposed NEMO
telescope to detect and identify point-like sources of high energy muon
neutrinos.Comment: To be published on BCN06 proceedings (Barcelona, July 4-7, 2006
Silencing of caveolin-1 in fibroblasts as opposed to epithelial tumor cells results in increased tumor growth rate and chemoresistance in a human pancreatic cancer model
Caveolin‑1 (Cav‑1) expression has been shown to be associated with tumor growth and resistance to chemotherapy in pancreatic cancer. The primary aim of this study was to explore the significance of Cav‑1 expression in pancreatic cancer cells as compared to fibroblasts in relation to cancer cell proliferation and chemoresistance, both in vitro and in vivo, in an immunodeficient mouse model. We also aimed to evaluate the immunohistochemical expression of Cav‑1 in the epithelial and stromal component of pancreatic cancer tissue specimens. The immunohistochemical staining of poorly differentiated tissue sections revealed a strong and weak Cav‑1 expression in the epithelial tumor cells and stromal fibroblasts, respectively. Conversely, the well‑differentiated areas were characterized by a weak epithelial Cav‑1 expression. Cav‑1 downregulation in cancer cells resulted in an increased proliferation in vitro; however, it had no effect on chemoresistance and growth gain in vivo. By contrast, the decreased expression of Cav‑1 in fibroblasts resulted in a growth advantage and the chemoresistance of cancer cells when they were co‑injected into immunodeficient mice to develop mixed fibroblast/cancer cell xenografts. On the whole, the findings of this study suggest that the downregulation of Cav‑1 in fibroblasts is associated with an increased tumor proliferation rate in vivo and chemoresistance. Further studies are warranted to explore whether the targeting of Cav‑1 in the stroma may represent a novel therapeutic approach in pancreatic cancer
First operations of the LNS heavy ions facility
Abstract A heavy ion facility is now available at Laboratorio Nazionale del Sud (LNS) of Catania. It can deliver beams with an energy up to 100 MeV/amu. The facility is based on a 15MV HVEC tandem and a K = 800 superconducting cyclotron as booster. During the last year, the facility came into operation. A 58Ni beam delivered by the tandem has been radially injected in the SC and then has been accelerated and extracted at 30 MeV/amu. In this paper the status of the facility together with the experience gained during the commissioning will be extensively reported
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