3,703 research outputs found

    Normalized solutions to mass supercritical Schroedinger equations with negative potential

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    We study the existence of positive solutions with prescribed L-2-norm for the mass supercritical Schrodinger equation -delta u+lambda u - V(x)u = |u|(p-2)u u is an element of H-1(R-N), lambda is an element of R, where V >= 0, N >= 1 and p is an element of(2+4/N, 2*), 2*: = 2N/N-2 if N >= 3 and 2* : = +infinity if N = 1,2. We treat two cases. Firstly, under an explicit smallness assumption on V and no condition on the mass, we prove the existence of a mountain pass solution at positive energy level, and we exclude the existence of solutions with negative energy. Secondly, requiring that the mass is smaller than some explicit bound, depending on V, and that V is not too small in a suitable sense, we find two solutions: a local minimizer with negative energy, and a mountain pass solution with positive energy. Moreover, a nonexistence result is proved

    Long-term results of iliac aneurysm repair with iliac branched endograft. A 5-year experience on 100 consecutive cases

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    Background: Iliac branch device (IBD) technique has been introduced as an appealing and effective solution to avoid complications occurring during repair of aorto-iliac aneurysm with extensive iliac involvement. Nevertheless, no large series with long-term follow-up of IBD are available. The aim of this study was to analyse safety and long-term efficacy of IBD in a consecutive series of patients.Methods: Between 2006 and 2011, 100 consecutive patients were enrolled in a prospective database on IBD. Indications included unilateral or bilateral common iliac artery aneurysms combined or not with abdominal aneurysms. Patients were routinely followed up with computed tomography. Data were reported according to the Kaplan-Meier method.Results: There were 96 males, mean age 74.1 years. Preoperative median common iliac aneurysm diameter was 40 mm (interquartile range (IQR): 35-44 mm). Sixty-seven patients had abdominal aortic aneurysm >35 mm (IQR: 40-57 mm) associated with iliac aneurysm. Eleven patients presented hypogastric aneurysm. Twelve patients underwent isolated iliac repair with IBD and 88 patients received associated endovascular aortic repair. Periprocedural technical success rate was 95%, with no mortality. Two patients experienced external iliac occlusion in the first month. At a median follow-up of 21 months (range 1-60) aneurysm growth >3 mm was detected in four iliac (4%) arteries. Iliac endoleak (one type III and two distal type I) developed in three patients and buttock claudication in four patients. Estimated patency rate of internal iliac branch was 91.4% at 1 and 5 years. Freedom from any reintervention rate was 90% at 1 year and 81.4% at 5 years. No late ruptures occurred.Conclusions: Long-term results show that IBD use can ensure persistent iliac aneurysm exclusion at 5 years, with low risk of reintervention. This technique can be considered as a first endovascular option in patients with extensive iliac aneurysm disease and favourable anatomy. (C) 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved

    Does the Presence of an Iliac Aneurysm Affect Outcome of Endoluminal AAA Repair? An Analysis of 336 Cases

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    AbstractObjective: to determine whether the presence of an iliac aneurysm compromises outcome of endovascular exclusion of AAA and to ascertain the fate of the iliac aneurysmal sac.Patients and methods: between April 1997 and March 2001, data on 336 consecutive patients undergoing endovascular repair for AAA were entered in a prospective database. Suitability for endovascular repair was assessed by preoperative contrast-enhanced computed tomography. A maximum common iliac artery (CIA) diameter ≄20mm was defined as iliac aneurysm. Patients with and without iliac aneurysms were compared to early (immediate conversion or perioperative death) and late failure (increase in aneurysm diameter or persisting graft-related endoleak, or late AAA rupture or conversion).Results: fifty-nine patients (18%) had iliac aneurysms, 19 were bilateral, for a total of 78 aneurysmal iliac arteries (median diameter 23mm; range 20–50mm). A distal seal was achieved by landing in 33 external iliac arteries, in 20 ectatic CIAs, and in 25 normal CIAs. Operating time differed significantly between patients with and without CIA aneurysms (153±71 vs 123±55min,p =0.0001), whereas no statistically significant differences were found with respect to early and late failure (2% vs 3%, p=0.5 and 14% vs 8%, p=0.11, respectively). There were no cases of buttock or colon necrosis. At a median follow-up of 14 months (range 0–46; i.q.r. 7–27 months) common iliac diameter decreased ≄2mm in 49 cases, remained stable in 25, and increased ≄2mm in 3.Conclusion: the presence of iliac aneurysm rendered endoluminal AAA repair more complex but did not affect feasibility and long-term outcome of the procedure. In our experience internal iliac exclusion was never associated with significant morbidity. These data may be useful when considering endovascular repair in high-risk patients with challenging anatomy

    Second-generation Thienopyridine use is not Associated with Better Early Perioperative Outcome During Carotid Stenting

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    AbstractObjectiveManagement of anti-platelet therapy during carotid artery stenting (CAS) is mainly based on indirect evidence from coronary stenting experience. There is common agreement on the use of thienopyridine (mainly second-generation) during CAS, but some patients are unsuitable for clopidogrel treatment and data on the benefit of its use in large CAS populations are lacking. The aim of this study was to investigate whether clopidogrel was associated with reduced perioperative morbidity in patients undergoing CAS.MethodsConsecutive patients undergoing CAS for primary carotid stenosis from 2004 to 2009 were reviewed. The independent association of clopidogrel and perioperative morbidity was assessed using multivariable analysis.ResultsA total of 1083 patients were treated (29% females, mean age 71.6 years); 825 (76%) patients were given clopidogrel starting before treatment. Clopidogrel use was associated with a non-significant reduction of perioperative stroke/death (4.3% vs. 2.4%; p = 0.13) and disabling stroke (1.2% vs. 1.0%; p = 1) rates. The non-significant stroke/death difference was similar in symptomatic (5.8% vs. 4.0%, p = 0.37) and asymptomatic (3.7% vs. 1.9%; p = 0.17) patients. After adjusting for demographics, co-morbidities and other therapies with multivariable analysis, clopidogrel use failed to show any significant independent association in decreasing operative risks. The only independent protective factor was use of statins (p = 0.010). The additional use of dual anti-platelet therapy did not add any advantage to the use of clopidogrel alone.ConclusionsThe suggested benefit of clopidogrel in decreasing the incidence of complications in patients undergoing CAS may be overestimated due to the overlapping effect of other more relevant factors (e.g., pleiotropy and plaque stabilisation from statins). More data and level I evidence are needed to understand which is the best medical management of CAS that will help improve outcomes of the procedure

    Quality of Life in Patients with Small Abdominal Aortic Aneurysm: The Effect of Early Endovascular Repair Versus Surveillance in the CAESAR Trial

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    AbstractObjectiveTo evaluate and compare changes over time in health-related quality of life reported by patients with small (4.1–5.4 cm) abdominal aortic aneurysms (AAAs) undergoing endovascular aortic aneurysm repair (EVAR) or surveillance.MethodsParticipants were randomly assigned to receive either early EVAR or surveillance within a multicentre, randomised clinical trial on small AAA (Comparison of surveillance vs. Aortic Endografting for Small Aneurysm Repair, CAESAR). Patient-reported health-related quality of life was assessed before randomisation, at 6 months and yearly thereafter using the Short Form 36 (SF-36) Health Survey.ResultsBetween 2004 and 2008, 360 patients (345 males, mean age 68.9 years) were randomised, 182 to early EVAR and 178 to surveillance. There was one perioperative death. Mean follow-up was 31.8 months. No significant difference in survival was found. At baseline, comparable quality of life scores were recorded in both treatment groups: Total SF-36: 73.0 versus 75.5 (p = 0.18), Physical domain: 71.4 versus 73.3 (p = 0.33); Mental health domain: 70.9 versus 72.7 (p = 0.33), in the EVAR arm versus the surveillance arm, respectively. Six months after randomisation, Total SF-36 and Physical and Mental domain scores were all significantly higher with respect to baseline in the EVAR group, while patients of the surveillance group scored lower. The differences between EVAR and surveillance arms in score changes at 6 months were significant and in favour of EVAR: Total score: difference 5.4; p = 0.0017; Physical: difference 3.8; p = 0.02; and Mental: difference 6.0; p = 0.0005. Differences between EVAR and surveillance diminished over time. At the last assessment, patients in both groups had decreased scores with a significant drop with respect to the baseline (−3.9 in EVAR, −6.3 in surveillance). There were no significant differences between the EVAR and surveillance arms: Total score: p = 0.25; Physical: p = 0.47; and Mental: p = 0.38.ConclusionsPatients with small AAA under surveillance compared with early EVAR had significant impaired functional health at 6 months after assignment. After a mean of 31.8 months, SF-36 health-related quality of life in patients allocated to early EVAR and surveillance was similar

    Role of Duplex Scan in Endoleak Detection After Endoluminal Abdominal Aortic Aneurysm Repair

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    AbstractObjective: to validate the role of duplex scan in endoleak detection in postoperative surveillance of endoluminal abdominal aneurysm repair (EAAR). Patients and methods between April 1997 and March 1999, 103 patients were eligible for duplex and computed tomography (CT) scan after EAAR. Mean follow-up was 8 months (range 1–24 months). The study protocol comprised concurrent examination with colour-duplex and CT scan at 1, 6, and 12 months after EAAR, for a total of 198 concurrent examinations. All duplex scan examinations were performed by two vascular surgeons with the same machine (ATL HDI 3000). Interobserver agreement in endoleak detection (Îș=1) and in type of endoleak (Îș=0.7) was evaluated in 50 random duplex examinations. Endoleak detection was examined comparatively in duplex and CT scan, the latter being the gold standard. Sensitivity and specificity tests together with negative- and positive-predictive values (NPV and PPV) were calculated. Results duplex scan was not feasible in one patient. On CT scan the endoleak rate was 4% at one month, 3% at 6 months, and 4% at one year. Overall, CT scan detected 12 endoleaks. With respect to endoleak detection, duplex scan revealed a great ability in ruling out false-negative results (sensitivity 91.7%, NPV 99.4%), but overestimated the presence of endoleak (specificity 98.4%, PPV 78.6%). Regarding type of endoleak, the ability of duplex scan to identify the source of endoleak was low (sensitivity 66.7%). Conclusions duplex scan, if validated, appears to be a reliable means for excluding the presence of endoleak after EAAR

    Z boson production in p+Pb collisions at sNN√=5.02 TeV measured with the ATLAS detector

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    The ATLAS Collaboration has measured the inclusive production of Z bosons via their decays into electron and muon pairs in p+Pb collisions at √ sNN = 5.02 TeV at the Large Hadron Collider. The measurements are made using data corresponding to integrated luminosities of 29.4 nb−1 and 28.1 nb−1 for Z → ee and Z → ””, respectively. The results from the two channels are consistent and combined to obtain a cross section times the Z → `` branching ratio, integrated over the rapidity region |y ∗ Z | < 3.5, of 139.8 ± 4.8 (stat.) ± 6.2 (syst.) ± 3.8 (lumi.) nb. Differential cross sections are presented as functions of the Z boson rapidity and transverse momentum, and compared with models based on parton distributions both with and without nuclear corrections. The centrality dependence of Z boson production in p+Pb collisions is measured and analyzed within the framework of a standard Glauber model and the model’s extension for fluctuations of the underlying nucleon-nucleon scattering cross sectionFil: Aad, G.. Aix-Marseille UniversitĂ©; FranciaFil: Abbott, B.. Oklahoma State University; Estados UnidosFil: Abdallah, J.. Academia Sinica; ChinaFil: Abdinov, O.. Azerbaijan Academy of Sciences; AzerbaiyĂĄnFil: Aben, R.. University of Amsterdam; PaĂ­ses BajosFil: Alconada Verzini, MarĂ­a Josefina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Alonso, Francisco. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Arduh, Francisco Anuar. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Dova, Maria Teresa. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Monticelli, Fernando Gabriel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Wahlberg, Hernan Pablo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Otero y Garzon, Gustavo Javier. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FĂ­sica de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FĂ­sica de Buenos Aires; ArgentinaFil: Piegaia, Ricardo Nestor. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FĂ­sica de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FĂ­sica de Buenos Aires; ArgentinaFil: Reisin, Hernan Diego. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FĂ­sica de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FĂ­sica de Buenos Aires; ArgentinaFil: Sacerdoti, Sabrina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FĂ­sica de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FĂ­sica de Buenos Aires; ArgentinaFil: Zieminska, D.. Indiana University; Estados UnidosFil: Zimine, N. I.. Joint Institute for Nuclear Research ; RusiaFil: Zimmermann, C.. UniversitĂ€t Mainz; AlemaniaFil: Zimmermann, S.. Albert-Ludwigs-UniversitĂ€t; AlemaniaFil: Zinonos, Z.. Georg-August-UniversitĂ€t; AlemaniaFil: Zinser, M.. UniversitĂ€t Mainz; AlemaniaFil: Ziolkowski, M.. UniversitĂ€t Siegen ; AlemaniaFil: Ćœivković, L.. University of Belgrade; SerbiaFil: Zobernig, G.. University of Wisconsin; Estados UnidosFil: Zoccoli, A.. UniversitĂ  di Bologna; ItaliaFil: Nedden, M. zur. Humboldt University; AlemaniaFil: Zurzolo, G.. UniversitĂ  di Napoli; ItaliaFil: Zwalinski, L.. Cern - European Organization For Nuclear Research; SuizaFil: The ATLAS Collaboration. No especifica

    Measurement of the production of a W boson in association with a charm quark in pp collisions at sqrt(s)=7 TeV with the ATLAS detector

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    The production of a W boson in association with a single charm quark is studied using 4.6 fb^-1 of pp collision data at sqrt(s)=7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96 +0.26 -0.30 at Q^2=1.9 GeV^2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio sigma(W^+ + bar{c})/sigma(W^- + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s-bar{s} quark asymmetry.Fil: ATLAS Collaboration, G. AAd, F. Monticelli, et al. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; Argentina. Cern - European Organization For Nuclear Research; Suiz

    Measurement of the parity-violating asymmetry parameter αb and the helicity amplitudes for the decay Λ0b→J/ψ+Λ0 with the ATLAS detector

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    A measurement of the parity-violating decay asymmetry parameter, αb, and the helicity amplitudes for the decay Λb0→J/ψ(ÎŒ+ÎŒ-)Λ0(pπ-) is reported. The analysis is based on 1400 Λb0 and Λ¯b0 baryons selected in 4.6  fb-1 of proton-proton collision data with a center-of-mass energy of 7 TeV recorded by the ATLAS experiment at the LHC. By combining the Λb0 and Λ¯b0 samples under the assumption of CP conservation, the value of αb is measured to be 0.30±0.16(stat)±0.06(syst). This measurement provides a test of theoretical models based on perturbative QCD or heavy-quark effective theory.Fil: F. Monticelli.Fil: Atlas Collaboration
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