153 research outputs found

    Experience With Radical Resection in The Management of Proximal Bile Duct Cancer

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    Multiple surgical and nonsurgical approaches have been advocated for the treatment of proximal bile duct cancer. However, survival appears longest when a resection can be performed. Fifteen patients treated at a university center were managed with an aggressive surgical approach. Resection of the tumor was performed in 13 of 15 patients (87%). Of the patients undergoing resection, major hepatic resection was performed in 8 (62%), while excision of vessels with reconstruction was performed in 5 (38%). Eleven of the 13 resected patients (85%) were discharged from the hospital. Clinical symptoms of recurrent disease occurred between 3 and 36 months after surgery in 7 patients, 6 of whom have died. Three other patients are alive at 5, 21, and 36 months without clinical evidence of recurrence. There was no correlation between the completeness of resection and the duration of disease-free survival

    Multiplicity fluctuations in nuclear collisions at 158 A GeV

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    System size dependence of multiplicity fluctuations of charged particles produced in nuclear collisions at 158 A GeV was studied in the NA49 CERN experiment. Results indicate a non-monotonic dependence of the scaled variance of the multiplicity distribution with a maximum for semi-peripheral Pb+Pb interactions with number of projectile participants of about 35. This effect is not observed in a string-hadronic model of nuclear collision HIJING.Comment: Presented at "Focus on Multiplicity", 17-19 of June, Bari, Ital

    Electric charge fluctuations in central Pb+Pb collisions at 20, 30, 40, 80 and 158 AGeV

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    Results are presented on event-by-event electric charge fluctuations in central Pb+Pb collisions at 20, 30, 40, 80 and 158 AGeV. The observed fluctuations are close to those expected for a gas of pions correlated by global charge conservation only. These fluctuations are considerably larger than those calculated for an ideal gas of deconfined quarks and gluons. The present measurements do not necessarily exclude reduced fluctuations from a quark-gluon plasma because these might be masked by contributions from resonance decays.Comment: 19 pages, 8 figure

    Omega and Antiomega production in central Pb+Pb collisions at 40 and 158 AGeV

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    Results are presented on Omega production in central Pb+Pb collisions at 40 and 158 AGeV beam energy. Given are transverse-mass spectra, rapidity distributions, and total yields for the sum Omega+Antiomega at 40 AGeV and for Omega and Antiomega separately at 158 AGeV. The yields are strongly under-predicted by the string-hadronic UrQMD model and are in better agreement with predictions from a hadron gas models.Comment: 5 papes, 4 figures, 1 table, updated figure 4 and table 1. Final version, including some editorial changes, as published in PR

    Report from NA49

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    The most recent data of NA49 on hadron production in nuclear collisions at CERN SPS energies are presented. Anomalies in the energy dependence of pion and kaon production in central Pb+Pb collisions are observed. They suggest that the onset of deconfinement is located at about 30 AGeV. Large multiplicity and transverse momentum fluctuations are measured for collisions of intermediate mass systems at 158 AGeV. The need for a new experimental programme at the CERN SPS is underlined.Comment: invited talk presented at Quark Matter 2004, 10 page

    System-size dependence of strangeness production in nucleus-nucleus collisions at sqrt{s_{NN}}=17.3 GeV

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    Emission of pi, K, phi and Lambda was measured in near-central C+C and Si+Si collisions at 158 AGeV beam energy. Together with earlier data for p+p, S+S and Pb+Pb, the system-size dependence of relative strangeness production in nucleus-nucleus collisions is obtained. Its fast rise and the saturation observed at about 60 participating nucleons can be understood as onset of the formation of coherent partonic subsystems of increasing size.Comment: Phys.Rev.Lett in print; version2: changes made according to the request of the referee

    System size dependence of strange particle yields and spectra at sqrt(s)=17.3 GeV

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    Yields and spectra of strange hadrons (K+, K-, phi, Lambda and Antilambda) as well as of charged pions were measured in near central C+C and Si+Si collisions at 158 AGeV beam energy with the NA49 detector. Together with earlier data for p+p, S+S and Pb+Pb reactions the system size dependence can be studied. Relative strangeness production rises fast and saturates at about 60 participating nucleons; the net hyperon spectra show an increasing shift towards midrapidity for larger colliding nuclei. An interpretation based on the formation of coherent systems of increasing volume is proposed. The transverse mass spectra can be described by a blast wave ansatz. Increasing flow velocity is accompanied by decreasing temperatures for both kinetic and chemical freeze out. The increasing gap between inelastic and elastic decoupling leaves space for rescattering.Comment: 8 pages, 6 figures, Proceedings of the Hot Quarks 2004 worksho
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