1,040 research outputs found

    Logarithmic entanglement scaling in dissipative free-fermion systems

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    We study the quantum information spreading in one-dimensional free-fermion systems in the presence of localized thermal baths. We employ a nonlocal Lindblad master equation to describe the system-bath interaction, in the sense that the Lindblad operators are written in terms of the Bogoliubov operators of the closed system, and hence are nonlocal in space. The statistical ensemble describing the steady state is written in terms of a convex combination of the Fermi-Dirac distributions of the baths. Due to the singularity of the free-fermion dispersion, the steady-state mutual information exhibits singularities as a function of the system parameters. While the mutual information generically satisfies an area law, at the singular points it exhibits logarithmic scaling as a function of subsystem size. By employing the Fisher-Hartwig theorem, we derive the prefactor of the logarithmic scaling, which depends on the parameters of the baths and plays the role of an effective “central charge.” This is upper bounded by the central charge governing ground-state entanglement scaling. We provide numerical checks of our results in the paradigmatic tight-binding chain and the Kitaev chain

    Dead-cone searches in heavy-ion collisions using the jet tree

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    We explore the possibility of using the dead cone of heavy quarks as a region of the Lund plane where medium-induced gluon radiation can be isolated and characterised. The filling of the dead cone by medium-induced gluons is expected to be the result of the interplay between the minimum angle of such radiation due to transverse momentum broadening and the dead-cone angle. Since the measurement of a fully corrected Lund plane in heavy-ion collisions is currently challenging, we propose to use jet grooming techniques to identify a particular splitting in the jet tree that is both perturbative and sensitive to the dead-cone effect. To that end, we propose a new jet substructure groomer, dubbed Late-ktk_t, that selects the most collinear splitting in a QCD jet above a certain transverse momentum cutoff kt,cutk_{t,\rm{cut}}. The role of kt,cutk_{t,\rm{cut}} is to guarantee perturbative splittings, while selecting the most collinear splitting enhances the sensitivity to mass effects. As a proof of concept, we study the angular distribution of the splitting tagged by Late-ktk_t both analytically and with Monte Carlo simulations. First, we derive the logarithmic resummation structure in vacuum and demonstrate its capability to distinguish between inclusive and heavy-flavoured jets. Next, we extend the calculation for in-medium jets and show that medium-induced emissions lead to an enhancement of collinear emissions below the dead cone angle. Numerically, we demonstrate an excellent resilience of Late-ktk_t against uncorrelated thermal background, thus confirming this observable as a potential candidate to unveil medium dynamics around the dead cone regime

    The relapsed acute lymphoblastic leukemia network (ReALLNet): a multidisciplinary project from the spanish society of pediatric hematology and oncology (SEHOP)

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    Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer, with survival rates exceeding 85%. However, 15% of patients will relapse; consequently, their survival rates decrease to below 50%. Therefore, several research and innovation studies are focusing on pediatric relapsed or refractory ALL (R/R ALL). Driven by this context and following the European strategic plan to implement precision medicine equitably, the Relapsed ALL Network (ReALLNet) was launched under the umbrella of SEHOP in 2021, aiming to connect bedside patient care with expert groups in R/R ALL in an interdisciplinary and multicentric network. To achieve this objective, a board consisting of experts in diagnosis, management, preclinical research, and clinical trials has been established. The requirements of treatment centers have been evaluated, and the available oncogenomic and functional study resources have been assessed and organized. A shipping platform has been developed to process samples requiring study derivation, and an integrated diagnostic committee has been established to report results. These biological data, as well as patient outcomes, are collected in a national registry. Additionally, samples from all patients are stored in a biobank. This comprehensive repository of data and samples is expected to foster an environment where preclinical researchers and data scientists can seek to meet the complex needs of this challenging population. This proof of concept aims to demonstrate that a network-based organization, such as that embodied by ReALLNet, provides the ideal niche for the equitable and efficient implementation of “what's next” in the management of children with R/R ALL.Peer ReviewedPostprint (published version

    Effect of spinels on the mechanical and tribological behavior of plasma sprayed alumina based coatings

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    Plasma sprayed ceramic coatings are widely used to protect metallic substrates when high temperature and/or friction are developed in service. In particular, alumina based coatings have been extensively used. Examples of applications are pistons in pumps or internal combustion engines and steam valve spindles. Alumina is hard, it shows a very high oxidation resistance and it is not permeable to aggressive gases. However, the alumina main drawback is its low fracture toughness. Brittle fracture is one of the most common wear mechanisms reported for ceramics. It is well known that the fracture toughness and the operative conditions are the key parameters controlling the crack propagation throughout the material. As a consequence, transition from mild to severe wear in ceramic coatings is mainly controlled by the fracture toughness of the coating. The typical solutions to improve the fracture behavior of alumina coatings are based on mixing alumina powders with other ceramic powders with superior toughness. Alumina – Zircona systems are used in this way. When a mixture of ceramics is thermally sprayed, a very complex microstructure is attained in the coating. Nevertheless, a common feature can be pointed out for different systems: formation of spinels from both oxides is commonly reported. These phases seem to play an important role in the fracture behavior of the coatings and subsequently in their tribological behavior. This paper presents a summary of the work done in the microstructural, mechanical and tribological characterization of plasma sprayed alumina based coatings (Al2O3 – TiO2, Al2O3 – ZrO2 and Al2O3 – Cr2O3). Special attention is paid on the role played by spinels formed during deposition

    Risk Factors for Revision After Artificial Urinary Sphincter Implantation in Male Patients With Stress Urinary Incontinence: A 10-Year Retrospective Study.

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    Purpose To evaluate the preoperative and intraoperative risk factors for revision after artificial urinary sphincter (AUS) implantation in male patients with stress urinary incontinence (SUI). Methods A retrospective analysis from a prospectively maintained database was performed. Male patients, with moderate-tosevere SUI, undergoing AUS implantation were included. All patients underwent placement of AMS 800. Cause of revision, type of revision, and time to revision were recorded. Multivariable analyzes were performed using a logistic regression to investigate the risk factors. Competing risk analysis according to Fine-Gray model was used to study time to event data. Results A total of 70 patients were included. Revision surgery was performed in 22 of 70 patients (31.4%), after a median (interquartile range) time of 26.5 months (6.5–39.3 months). Overall, 19 of 22 repairs (86.4%) and 3 of 22 explants (13.6%) were recorded. Mechanical dysfunction, urethral erosion, urethral atrophy, and device infection were the causes of revision in 11 of 22 (50.0%), 6 of 22 (27.3%), 3 of 22 (13.6%), and 2 of 22 patients (9.1%). Vesicourethral anastomosis stenosis (P=0.02), urethral cuff size of 3.5 cm (P=0.029), and dual implantation (P=0.048) were independent predictors for revision. Vesicourethral anastomosis stenosis (P=0.01) and urethral cuff size of 3.5 cm (P=0.029) predicted a lower survival of the AUS. Conclusions The vesicourethral anastomosis stenosis, urethral cuff size of 3.5 cm, and dual implantation are independent predictors for revision after AUS implantation. However, only the vesicourethral anastomosis stenosis and urethral cuff size of 3.5 cm predict a lower survival of AUS.pre-print441 K

    Entanglement Dynamics after a Quench in Ising Field Theory: A Branch Point Twist Field Approach

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    We extend the branch point twist field approach for the calculation of entanglement entropies to time-dependent problems in 1+1-dimensional massive quantum field theories. We focus on the simplest example: a mass quench in the Ising field theory from initial mass m0 to final mass m. The main analytical results are obtained from a perturbative expansion of the twist field one-point function in the post-quench quasi-particle basis. The expected linear growth of the RĂ©nyi entropies at large times mt ≫ 1 emerges from a perturbative calculation at second order. We also show that the RĂ©nyi and von Neumann entropies, in infinite volume, contain subleading oscillatory contributions of frequency 2m and amplitude proportional to (mt)−3/2. The oscillatory terms are correctly predicted by an alternative perturbation series, in the pre-quench quasi-particle basis, which we also discuss. A comparison to lattice numerical calculations carried out on an Ising chain in the scaling limit shows very good agreement with the quantum field theory predictions. We also find evidence of clustering of twist field correlators which implies that the entanglement entropies are proportional to the number of subsystem boundary points

    Does access to care play a role in liver cancer survival? The ten-year (2006-2015) experience from a population-based cancer registry in Southern Italy.

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    BACKGROUND: Hepatocellular carcinoma (HCC) is the most frequent primary invasive cancer of the liver. During the last decade, the epidemiology of HCC has been continuously changing in developed countries, due to more effective primary prevention and to successful treatment of virus-related liver diseases. The study aims to examine survival by level of access to care in patients with HCC, for all patients combined and by age. METHODS: We included 2018 adult patients (15-99 years) diagnosed with a primary liver tumour, registered in the Palermo Province Cancer Registry during 2006-2015, and followed-up to 30 October 2019. We obtained a proxy measure of access to care by linking each record to the Hospital Discharge Records and the Ambulatory Discharge Records. We estimated net survival up to 5 years after diagnosis by access to care ("easy access to care" versus "poor access to care"), using the Pohar-Perme estimator. Estimates were age-standardised using International Cancer Survival Standard (ICSS) weights. We also examined survival by access to care and age (15-64, 65-74 and ≄ 75 years). RESULTS: Among the 2018 patients, 62.4% were morphologically verified and 37.6% clinically diagnosed. Morphologically verified tumours were more frequent in patients aged 65-74 years (41.6%), while tumours diagnosed clinically were more frequent in patients aged 75 years or over (50.2%). During 2006-2015, age-standardised net survival was higher among HCC patients with "easy access to care" than in those with "poor access to care" (68% vs. 48% at 1 year, 29% vs. 11% at 5 years; p < 0.0001). Net survival up to 5 years was higher for patients with "easy access to care" in each age group (p < 0.0001). Moreover, survival increased slightly for patients with easier access to care, while it remained relatively stable for patients with poor access to care. CONCLUSIONS: During 2006-2015, 5-year survival was higher for HCC patients with easier access to care, probably reflecting progressive improvement in the effectiveness of health care services offered to these patients. Our linkage algorithm could provide valuable evidence to support healthcare decision-making in the context of the evolving epidemiology of hepatocellular carcinoma

    Towards a common European ethical and legal framework for conducting clinical research : the GATEKEEPER experience

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    This paper examines the ethical and legal challenges encountered during the GATEKEEPER Project and how these challenges informed the development of a comprehensive framework for future Large-Scale Pilot (LSP) projects. GATEKEEPER is a LSP Project with 48 partners conducting 30 implementation studies across Europe with 50,000 target participants grouped into 9 Reference Use Cases. The project underscored the complexity of obtaining ethical approval across various jurisdictions with divergent regulations and procedures. Through a detailed analysis of the issues faced and the strategies employed to navigate these challenges, this study proposes an ethical and legal framework. This framework, derived from a comparative analysis of ethical application forms and regulations, aims to streamline the ethical approval process for future LSP research projects. By addressing the hurdles encountered in GATEKEEPER, the proposed framework offers a roadmap for more efficient and effective project management, ensuring smoother implementation of similar projects in the future
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