2,223 research outputs found

    On the determinant formula in the inverse scattering procedure with a partially known steplike potential

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    We are concerned with the inverse scattering problem for the full line Schr\"odinger operator x2+q(x)-\partial_x^2+q(x) with a steplike potential qq a priori known on R+=(0,)\Reals_+=(0,\infty). Assuming qR+q|_{\Reals_+} is known and short range, we show that the unknown part qRq|_{\Reals_-} of qq can be recovered by {equation*} q|_{\Reals_-}(x)=-2\partial_x^2\log\det(1+(1+\mathbb{M}_x^+)^{-1}\mathbb{G}_x), {equation*} where Mx+\mathbb{M}_x^+ is the classical Marchenko operator associated to qR+q|_{\Reals_+} and Gx\mathbb{G}_x is a trace class integral Hankel operator. The kernel of Gx\mathbb{G}_x is explicitly constructed in term of the difference of two suitably defined reflection coefficients. Since qRq|_{\Reals_-} is not assumed to have any pattern of behavior at -\infty, defining and analyzing scattering quantities becomes a serious issue. Our analysis is based upon some subtle properties of the Titchmarsh-Weyl mm-function associated with R\Reals_-

    Phenomenological three-cluster model of 6^{6}He

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    By using the method of hyperspherical functions within the appropriate for this method K_{\min} approximation, the simple three-cluster model for description of the ground state and the continuous spectrum states of \6He is developed. It is shown that many properties of \6He (its large rms radius and large values of the matrix elements of electromagnetic transitions from the ground state into the continuous spectrum) follow from the fact that the potential energy of \6He system decreases very slowly (as \rho^{-3}) and the binding energy is small

    Variation of the character of spin-orbit interaction by Pt intercalation underneath graphene on Ir(111)

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    Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).-- et al.The modification of the graphene spin structure is of interest for novel possibilities of application of graphene in spintronics. The most exciting of them demand not only high value of spin-orbit splitting of the graphene states, but non-Rashba behavior of the splitting and spatial modulation of the spin-orbit interaction. In this work we study the spin and electronic structure of graphene on Ir(111) with intercalated Pt monolayer. Pt interlayer does not change the 9.3×9.3 superlattice of graphene, while the spin structure of the Dirac cone becomes modified. It is shown that the Rashba splitting of the π state is reduced, while hybridization of the graphene and substrate states leads to a spin-dependent avoided-crossing effect near the Fermi level. Such a variation of spin-orbit interaction combined with the superlattice effects can induce a topological phase in graphene.The work was partially supported by grants of Saint Petersburg State University for scientific investigations (Grants No. 11.38.271.2014, No. 15.61.202.2015 and No. 11.37.634.2013) and Russian Foundation for Basic Research (RFBR) projects (No. 13-02-91327). We acknowledge the financial support of the University of Basque Country UPV/EHU (Grant No. GIC07-IT-756-13), the Departamento de Educacion del Gobierno Vasco, and the Spanish Ministerio de Ciencia e Innovacion (Grant No. FIS2010-19609-C02-01), the Spanish Ministry of Economy and Competitiveness MINECO (Grant No. FIS2013-48286-C2-1-P), and the Tomsk State University Competitiveness Improvement Program.Peer Reviewe

    Variation of the character of spin-orbit interaction by Pt intercalation underneath graphene on Ir(111)

    Get PDF
    The modification of the graphene spin structure is of interest for novel possibilities of application of graphene in spintronics. The most exciting of them demand not only high value of spin-orbit splitting of the graphene states, but non-Rashba behavior of the splitting and spatial modulation of the spin-orbit interaction. In this work we study the spin and electronic structure of graphene on Ir(111) with intercalated Pt monolayer. Pt interlayer does not change the 9.3×9.3 superlattice of graphene, while the spin structure of the Dirac cone becomes modified. It is shown that the Rashba splitting of the π state is reduced, while hybridization of the graphene and substrate states leads to a spin-dependent avoided-crossing effect near the Fermi level. Such a variation of spin-orbit interaction combined with the superlattice effects can induce a topological phase in graphene

    O-15 Randomized, phase 3 study of second-line tislelizumab vs chemotherapy in advanced or metastatic esophageal squamous cell carcinoma (RATIONALE 302) in the overall population and Europe/North America subgroup

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    Background: The global Phase 3 study RATIONALE 302 (NCT03430843) evaluated the efficacy and safety of second-line tislelizumab, an anti-PD-1 antibody, in patients with advanced or metastatic esophageal squamous cell carcinoma (ESCC). Here, we report data from the overall and Europe/North America (EU/NA) populations. Methods: Eligible adult patients had disease progression during or after first-line systemic therapy, ≥1 evaluable lesion per RECIST v1.1 and an Eastern Cooperative Oncology Group performance score (ECOG PS) of ≤1. Patients were randomized (1:1) to receive tislelizumab 200 mg intravenously Q3W or investigator-chosen chemotherapy (paclitaxel, docetaxel, or irinotecan) and treated until disease progression, intolerable toxicity, or withdrawal. Stratification factors included chemotherapy option, region, and ECOG PS. The primary endpoint was overall survival (OS) in all patients (ITT population). The key secondary endpoint was OS in PD-L1 positive (vCPS ≥10%) patients; other secondary endpoints included progression-free survival (PFS), overall response rate (ORR), duration of response (DoR), health-related quality of life and safety. Results: 512 patients (overall population) were randomized to tislelizumab (n=256) or chemotherapy (n=256), of which 108 (21%) patients were enrolled into EU/NA subgroup (n=55 tislelizumab, n=53 chemotherapy). On 1 December 2020 (data cut-off), median follow-up was 6.9 and 6.8 months in the overall population and EU/NA subgroup, respectively. Tislelizumab improved OS vs chemotherapy in the overall population (median OS 8.6 vs 6.3 months; HR 0.70, 95% CI 0.57–0.85; p=0.0001); survival benefit was consistently observed in the EU/NA subgroup (median OS 11.2 vs 6.3 months; HR 0.55; 95% CI 0.35–0.87). Treatment with tislelizumab was associated with improved ORR (20.3% [95% CI 15.6%–25.8%] vs 9.8% [95% CI 6.4%–14.1%]) and median DoR (7.1 vs 4.0 months; HR 0.42, 95% CI 0.23–0.75) vs chemotherapy in the overall population. Improvement in ORR (20.0% [95% CI 10.4%–33.0%] vs 11.3% [95% CI 4.3%–23.0%]) and median DOR (5.1 vs 2.1 months; HR 0.42, 95% CI 0.13–1.39) was also observed in the EU/NA subgroup. Fewer patients had Grade ≥3 treatment-emergent adverse events (TEAE) with tislelizumab vs chemotherapy in both the overall and EU/NA populations (46% vs 68% and 56% vs 71%, respectively). Of these, fewer Grade ≥3 AEs were treatment-related with tislelizumab vs chemotherapy (overall: 19% vs 56%; EU/NA: 13% vs 51%). AEs leading to death were similar with tislelizumab vs chemotherapy (overall: 14% vs 12%; EU/NA: 6% vs 5%). Conclusions: Second-line tislelizumab demonstrated statistically significant and clinically meaningful improvement in OS versus chemotherapy in patients with advanced or metastatic ESCC. Tislelizumab demonstrated a tolerable safety profile. Efficacy and safety results from the EU/NA subgroup were consistent with the overall population. Clinical trial identification: NCT03430843
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