124 research outputs found

    Noise and Periodic Modulations in Neural Excitable Media

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    We have analyzed the interplay between noise and periodic modulations in a mean field model of a neural excitable medium. To this purpose, we have considered two types of modulations; namely, variations of the resistance and oscillations of the threshold. In both cases, stochastic resonance is present, irrespective of if the system is monostable or bistable.Comment: 13 pages, RevTex, 5 PostScript figure

    Long-term outcome of liver transplantation for unresectable liver metastases from neuroendocrine neoplasms: a Belgian retrospective multi-centre study

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    peer reviewedBackground: Liver transplantation (LT) is the only curative treatment for unresectable liver metastases from neuroendocrine neoplasms (NEN-Liver-Mets). While recurrence is frequent after LT, there is limited data available in the literature on the outcome of recurrent patients. Methods: We retrospectively reviewed the medical records of all patients who underwent LT by NEN-Mets at the six LT centres in Belgium from 1986 to 2020. Patient and tumour characteristics, indication for transplantation, overall survival (OS), disease-free survival (DFS), and tumour recurrence and outcomes were analysed. Results: Forty patients underwent a LT for NEN-Liver-Mets in Belgium. Twenty-nine patients were male (74.2%) with a mean age of 41.9 and 47.1 years at the time of NEN diagnosis and LT, respectively. WHO classification was available for 32 patients and changed over time (see table below). OS post-LT at 1-, 5-, and 10-years are: 84,3%, 65,0% and 54,6% respectively, while the overall DFS are: 76.3%, 44.5% and 38.2% in the same intervals. Patients transplanted after 2010 showed better OS at 5-and 10-years (74.8% and 74.8%) when compared with patients transplanted before (60,0% and 49.5%). Twenty patients (50%) presented a NEN recurrence, of this, 14 (70%) were transplanted before 2010 and only 6 (30%) were transplanted afterwards (p=0.03). The median time for recurrence diagnosis was 12.3 months (range: 5.1 to 69.2). The most frequent recurrence treatments were surgical resection, somatostatin analogs, chemotherapy, and sunitinib therapy (8, 6, 6, and 4 patients, respectively). Survival rates were 89.5% and 56.1% at 1- and 5-years after recurrence diagnosis.Conclusions: Patients transplanted for unresectable NEN-Liver metastases had good long-term survival. Although the total recurrence rate is high, it decreased dramatically after 2010, probably due to better patient selection. Furthermore, recurrence treatment should be recommended as it may prolong patient survival

    Insulin does not stimulate β-alanine transport into human skeletal muscle

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    To test whether high circulating insulin concentrations influence the transport of β-alanine into skeletal muscle at either saturating or subsaturating β-alanine concentrations, we conducted two experiments whereby β-alanine and insulin concentrations were controlled. In experiment 1, 12 men received supraphysiological amounts of β-alanine intravenously (0.11 g·kg−1·min−1 for 150 min), with or without insulin infusion. β-Alanine and carnosine were measured in muscle before and 30 min after infusion. Blood samples were taken throughout the infusion protocol for plasma insulin and β-alanine analyses. β-Alanine content in 24-h urine was assessed. In experiment 2, six men ingested typical doses of β-alanine (10 mg/kg) before insulin infusion or no infusion. β-Alanine was assessed in muscle before and 120 min following ingestion. In experiment 1, no differences between conditions were shown for plasma β-alanine, muscle β-alanine, muscle carnosine and urinary β-alanine concentrations (all P > 0.05). In experiment 2, no differences between conditions were shown for plasma β-alanine or muscle β-alanine concentrations (all P > 0.05). Hyperinsulinemia did not increase β-alanine uptake by skeletal muscle cells, neither when substrate concentrations exceed the Vmax of β-alanine transporter TauT nor when it was below saturation. These results suggest that increasing insulin concentration is not necessary to maximize β-alanine transport into muscle following β-alanine intake

    Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at s = 13 TeV with the ATLAS detector

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    A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, , and tb) or third-generation leptons (τν and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

    Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at √s = 13 TeV with the ATLAS detector

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    A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at √s = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, tt¯, and tb) or third-generation leptons (τν and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion
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