1,206 research outputs found
Sudakov expansions at one loop and beyond for charged scalar and fermion pair production in SUSY models at future Linear Colliders
We consider the high energy behaviour of the amplitudes for pair production
of charged leptons, quarks, Higgs bosons, sleptons, squarks and charginos at
lepton colliders. We give the general expressions of the leading quadratic and
subleading linear logarithms that appear at the one loop level, and derive the
corresponding resummed expansions to \underline{subleading} logarithmic order
accuracy. Under the assumption of a relatively light SUSY scenario and choosing
the MSSM as a specific model, we compare the predictions of the one-loop and of
the resummed expansions at variable energy. We show that the two predictions
are very close in the one TeV regime, but drastically differ in the few ()
TeV range.Comment: 43 pages, 13 Encapsulated PostScript figure
The tyrosine kinase receptor c-met, its cognate ligand HGF and the tyrosine kinase receptor trasducers STAT3, PI3K and RHO in thyroid nodules associated with Hashimoto's thyroiditis: an immunohisto-chemical characterization
Hepatocyte growth factor (HGF) exerts proliferative activities in thyrocytes upon binding to its tyrosine kinase receptor c-met and is also expressed in benign thyroid nodules as well as in Hashimoto's thyroiditis (HT)
Meta-analysis of open versus endovascular repair for ruptured descending thoracic aortic aneurysm
IntroductionRuptured descending thoracic aortic aneurysm (rDTAA) is associated with high mortality rates. Data supporting endovascular thoracic aortic aneurysm repair (TEVAR) to reduce mortality compared with open repair are limited to small series. We investigated published reports for contemporary outcomes of open and endovascular repair of rDTAA.MethodsWe systematically reviewed all studies describing the outcomes of rDTAA treated with open repair or TEVAR since 1995 using MEDLINE, Cochrane Library CENTRAL, and Excerpta Medica Database (EMBASE) databases. Case reports or studies published before 1995 were excluded. All articles were critically appraised for relevance, validity, and availability of data regarding treatment outcomes. All data were systematically pooled, and meta-analyses were performed to investigate 30-day mortality, myocardial infarction, stroke, and paraplegia rates after both types of repair.ResultsOriginal data of 224 patients (70% male) with rDTAA were identified: 143 (64%) were treated with TEVAR and 81 (36%) with open repair. Mean age was 70 ± 5.6 years. The 30-day mortality was 19% for patients treated with TEVAR for rDTAA compared 33% for patients treated with open repair, which was significant (odds ratio [OR], 2.15, P = .016). The 30-day occurrence rates of myocardial infarction (11.1% vs 3.5%; OR, 3.70, P < .05), stroke (10.2% vs 4.1%; OR, 2.67; P = .117), and paraplegia (5.5% vs 3.1%; OR, 1.83; P = .405) were increased after open repair vs TEVAR, but this failed to reach statistical significance for stroke and paraplegia. Five additional patients in the TEVAR group died of aneurysm-related causes after 30 days, during a median follow-up of 17 ± 10 months. Follow-up data after open repair were insufficient. The estimated aneurysm-related survival at 3 years after TEVAR was 70.6%.ConclusionEndovascular repair of rDTAA is associated with a significantly lower 30-day mortality rate compared with open surgical repair. TEVAR was associated with a considerable number of aneurysm-related deaths during follow-up
Endovascular stenting of the ascending aorta for type A aortic dissections in patients at high risk for open surgery
Background: Open repair is the gold standard for type A aortic dissection (TAAD). Endovascular option has been proposed in very limited and selected TAAD patients. We report our experience with endovascular TAAD repair. Methods: Inclusion criteria were: (1) entry tear in the ascending aorta; (2) proximal landing zone of at least 2 cm; (3) distance between entry tear and brachio-cephalic trunk of at least 0.5 cm; (4) no signs of cardiac tamponade or severe aortic regurgitation and (5) no signs of aortic branches ischaemia. Patients with cardiac revascularisation from ascending aorta were excluded. Results: From April 2009 to June 2012, 37 patients with TAAD were admitted to our hospital. As many as 28 underwent surgical repair and 9 were considered at high surgical risk in a multidisciplinary meeting. Four met our inclusion criteria for an endovascular approach. Two of them had previous ascending aortic repair for TAAD and one had aortic valve replacement. Technical success was achieved in 100% of the patients. No mortality was registered during a median follow-up of 15 months (range 4-39 months), no migration of the graft and complete false lumen thrombosis of the ascending aorta in three patients. Conclusion: Endovascular treatment of TAAD is challenging but feasible in a selected subset of patients. Further research remains mandatory. © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved
Long-term outcomes of surgical aortic fenestration for complicated acute type B aortic dissections
IntroductionSurgical aortic fenestration has been used for treating ischemic complications of acute type B aortic dissection (ABAD). In the current endovascular era, surgical aortic fenestration may serve as an alternative for these patients after percutaneous failure. The purpose of this study is to describe our surgical suprarenal and infrarenal aortic fenestration technique, and to report the long-term outcomes of this approach in the management of complicated ABAD.MethodsWe retrospectively analyzed the in-hospital and long-term outcomes of 18 patients treated with either suprarenal (n = 10) or infrarenal surgical fenestration (n = 8) for complicated ABAD between 1988 and 2002. Suprarenal fenestration was performed through a thoracoabdominal incision in the 10th intercostal space, whereas patients treated with infrarenal fenestration underwent a midline laparotomy. A longitudinal aortotomy was performed and the true and false lumens were identified, followed by a wide resection of the intimal membrane.ResultsMedian age was 60 years (range, 48-82 years) and 89% (n = 16) were male. The in-hospital mortality was 22% (n = 4), which included two deaths after suprarenal fenestration and two deaths after infrarenal fenestration. In the remaining patients, full visceral, renal, and lower extremity function was recovered, except for 1 patient with paraplegia at admission in which the neurologic deficit was permanent. Median follow-up of the surviving patients was 10.0 years (interquartile range, 12.5; range, 0.5-20 years). During follow-up, none of the patients developed renal or visceral ischemia, or ischemic complications to the lower extremities, and no significant dilatations of the treated aortic segments were noted. Three of 14 patients with ABAD who were discharged alive expired during the follow-up period due to causes unrelated to the surgical procedure.ConclusionSurgical aortic fenestration represents an effective and durable option for treating ischemic complications of ABAD. Actually, this conservative surgical technique may serve as the alternative treatment in case of contraindications or failure of endovascular management of complicated ABAD
Freeze-out configuration properties in the 197Au + 197Au reaction at 23 AMeV
Data from the experiment on the 197Au + 197Au reaction at 23 AMeV are
analyzed with an aim to find signatures of exotic nuclear configurations such
as toroid-shaped objects. The experimental data are compared with predictions
of the ETNA code dedicated to look for such configurations and with the QMD
model. A novel criterion of selecting events possibly resulting from the
formation of exotic freeze-out configurations, "the efficiency factor", is
tested. Comparison between experimental data and model predictions may indicate
for the formation of flat/toroidal nuclear systems
Correlations between isospin dynamics and Intermediate Mass Fragments emission time scales: a probe for the symmetry energy in asymmetric nuclear matter
We show new data from the Ni+Sn and Ni+Sn
reactions studied in direct kinematics with the CHIMERA detector at INFN-LNS
and compared with the reverse kinematics reactions at the same incident beam
energy (35 A MeV). Analyzing the data with the method of relative velocity
correlations, fragments coming from statistical decay of an excited
projectile-like (PLF) or target-like (TLF) fragments are discriminated from the
ones coming from dynamical emission in the early stages of the reaction. By
comparing data of the reverse kinematics experiment with a stochastic mean
field (SMF) + GEMINI calculations our results show that observables from neck
fragmentation mechanism add valuable constraints on the density dependence of
symmetry energy. An indication is found for a moderately stiff symmetry energy
potential term of EOS.Comment: Talk given by E. De Filippo at the 11th International Conference on
Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1,
2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference
Series (JPCS
Kinematical coincidence method in transfer reactions
A new method to extract high resolution angular distributions from
kinematical coincidence measurements in binary reactions is presented.
Kinematic is used to extract the center of mass angular distribution from the
measured energy spectrum of light particles. Results obtained in the case of
10Be+p-->9Be+d reaction measured with the CHIMERA detector are shown. An
angular resolution of few degrees in the center of mass is obtained.Comment: 6 Page 10 Figures submitted to Nuclear Instruments and Methods
Dipolar degrees of freedom and Isospin equilibration processes in Heavy Ion collisions
Background: In heavy ion collision at the Fermi energies Isospin
equilibration processes occur- ring when nuclei with different charge/mass
asymmetries interacts have been investigated to get information on the
nucleon-nucleon Iso-vectorial effective interaction. Purpose: In this paper,
for the system 48Ca +27 Al at 40 MeV/nucleon, we investigate on this process by
means of an observable tightly linked to isospin equilibration processes and
sensitive in exclusive way to the dynamical stage of the collision. From the
comparison with dynamical model calculations we want also to obtain information
on the Iso-vectorial effective microscopic interaction. Method: The average
time derivative of the total dipole associated to the relative motion of all
emitted charged particles and fragments has been determined from the measured
charges and velocities by using the 4? multi-detector CHIMERA. The average has
been determined for semi- peripheral collisions and for different charges Zb of
the biggest produced fragment. Experimental evidences collected for the systems
27Al+48Ca and 27Al+40Ca at 40 MeV/nucleon used to support this novel method of
investigation are also discussed.Comment: Submitted for publication on Phys. Rev. C. 0n 24-oct-201
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