1,196 research outputs found

    Sudakov expansions at one loop and beyond for charged scalar and fermion pair production in SUSY models at future Linear Colliders

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    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 (2,32,3) 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

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    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

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    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

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    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

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    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

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    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

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    We show new data from the 64^{64}Ni+124^{124}Sn and 58^{58}Ni+112^{112}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

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    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

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    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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