116 research outputs found
Discrete-time Quantum Walks in random artificial Gauge Fields
Discrete-time quantum walks (DTQWs) in random artificial electric and
gravitational fields are studied analytically and numerically. The analytical
computations are carried by a new method which allows a direct exact analytical
determination of the equations of motion obeyed by the average density
operator. It is proven that randomness induces decoherence and that the quantum
walks behave asymptotically like classical random walks. Asymptotic diffusion
coefficients are computed exactly. The continuous limit is also obtained and
discussed.Comment: 16 pages, 9 figures. Submitted to Physica
Fermion confinement via Quantum Walks in 2D+1 and 3D+1 spacetime
We analyze the properties of a two and three dimensional quantum walk that
are inspired by the idea of a brane-world model put forward by Rubakov and
Shaposhnikov [1]. In that model, particles are dynamically confined on the
brane due to the interaction with a scalar field. We translated this model into
an alternate quantum walk with a coin that depends on the external field, with
a dependence which mimics a domain wall solution. As in the original model,
fermions (in our case, the walker), become localized in one of the dimensions,
not from the action of a random noise on the lattice (as in the case of
Anderson localization), but from a regular dependence in space. On the other
hand, the resulting quantum walk can move freely along the "ordinary"
dimension.Comment: 5 pages, 6 figure
Discrete-time quantum walks: continuous limit and symmetries
The continuous limit of one dimensional discrete-time quantum walks with
time- and space-dependent coefficients is investigated. A given quantum walk
does not generally admit a continuous limit but some families (1-jets) of
quantum walks do. All families (1-jets) admitting a continuous limit are
identified. The continuous limit is described by a Dirac-like equation or,
alternately, a couple of Klein-Gordon equations. Variational principles leading
to these equations are also discussed, together with local invariance
properties
Immune Checkpoint Blockade in Lung Carcinoids with Aggressive Behaviour: One More Arrow in Our Quiver?
Lung carcinoids are well-differentiated and low-/intermediate-grade neuroendocrine neoplasms of the lung. Given their relative rarity, and the paucity of data available from prospective studies, no global consensus exists on the systemic treatment of these tumours. In recent years, immune checkpoint inhibitors have revolutionized cancer management and are under evaluation in patients with diverse types of neuroendocrine neoplasms. The aim of this narrative review is to analyse all available data for the use of approved immune checkpoint inhibitors in patients with lung carcinoids. We performed an extensive search for relevant data sources and found five published articles, one meeting abstract, and nine registered clinical trials indicating a growing interest of researchers in this field, and providing preliminary evidence of efficacy for combined nivolumab plus ipilimumab and durvalumab plus tremelimumab regimens in the treatment of advanced and/or metastatic lung carcinoids
Late Endocrine and Metabolic Sequelae and LongâTerm Monitoring of Classical Hodgkin Lymphoma and Diffuse Large BâCell Lymphoma Survivors: A Systematic Review by the Fondazione Italiana Linfomi
Background: Overall survival after lymphoma has improved in recent years, but the high prevalence of late treatmentârelated sequelae has been observed as a counterpart. Method: In this systematic review, FIL researchers aimed to: (i) estimate the incidence or prevalence of late endocrineâmetabolic sequelae, (ii) evaluate the effects of modern therapeutic approaches on incidence or prevalence of late endocrineâmetabolic sequelae, and (iii) determine whether there is evidence of followâup schemes for their screening/early diagnosis in the subset of longâterm classical Hodgkin lymphoma (cHL) and diffuse large Bâcell lymphoma (DLBCL) survivors treated at adult age. The MEDLINE, Embase and the Cochrane Library databases were searched for relevant articles published up to October, 2020. The study selection process was conducted by three independent reviewers and was reported according to the Preferred Reporting Items for Systematic Reviews and MetaâAnalyses (PRISMA) guidelines. A risk of bias assessment was performed using the Cochrane tool for randomized trials and the NewcastleâOttawa Scale for observational studies. Results: In the final analysis, eight studies were included, four of which focused on thyroid disease, two on gonadal dysfunction, one on bone disease and one on metabolic syndrome. Hypothyroidism was reported in up to 60% of adult cHL survivors and was frequently recorded even with modern radiotherapy approaches. Menopause occurred in 52â72% of women after chemotherapy. An 86% reduction in vertebral density was reported following RâCHOPâlike chemotherapy. Sarcopenia and metabolic syndrome were reported in 37.9% and 60% of patients, respectively. No validated screening protocols were found for the early diagnosis of longâterm treatmentârelated endocrine and metabolic sequelae, thus the authors finally suggest the execution of screening exams according to the risk category which were identified in the epidemiologic studies
Modeling andsimulationofspeedselectiononleftventricular assist devices
The control problem for LVADs is to set pump speed such that cardiac output and pressure perfusion are within acceptable physiological ranges. However, current technology of LVADs cannot provide for a closed-loop control scheme that can make adjustments based on the patient\u27s level of activity. In this context, the SensorART Speed Selection Module (SSM) integrates various hardware and software components in order to improve the quality of the patients\u27 treatment and the workflow of the specialists. It enables specialists to better understand the patient-device interactions, and improve their knowledge. The SensorART SSM includes two tools of the Specialist Decision Support System (SDSS); namely the Suction Detection Tool and the Speed Selection Tool. A VAD Heart Simulation Platform (VHSP) is also part of the system. The VHSP enables specialists to simulate the behavior of a patient?s circulatory system, using different LVAD types and functional parameters. The SDSS is a web-based application that offers specialists with a plethora of tools for monitoring, designing the best therapy plan, analyzing data, extracting new knowledge and making informative decisions. In this paper, two of these tools, the Suction Detection Tool and Speed Selection Tool are presented. The former allows the analysis of the simulations sessions from the VHSP and the identification of issues related to suction phenomenon with high accuracy 93%. The latter provides the specialists with a powerful support in their attempt to effectively plan the treatment strategy. It allows them to draw conclusions about the most appropriate pump speed settings. Preliminary assessments connecting the Suction Detection Tool to the VHSP are presented in this paper
Clinical use of a 180-day implantable glucose sensor improves glycated haemoglobin and time in range in patients with type 1 diabetes
Aims: This real-world study evaluated the changes in glycated haemoglobin (HbA1c) and continuous glucose monitoring (CGM) metrics associated with use of the implantable 180-day Eversense CGM System (Eversense) in patients with type 1 diabetes. Materials and methods: This was a prospective, multicentre, observational study among adult participants aged â„18 years with type 1 diabetes across seven diabetes-care centres in Italy who had Eversense inserted for the first time. HbA1c was measured at baseline and at 180 days. Changes in time in range [TIR (glucose 70â180 mg/dL)], time above range [TAR (glucose >180 mg/dL)], time below range [TBR (glucose <70 mg/dL)] and glycaemic variability were also assessed. Data were also analysed by previous CGM use and by mode of insulin delivery. Results: One-hundred patients were enrolled (mean age 36 ± 12 years, mean baseline HbA1c 7.4 ± 0.92% [57 ± 10 mmol/mol]). Fifty-six per cent of patients were users of the continuous subcutaneous insulin infusion pump and 45% were previous users of CGM. HbA1c significantly decreased in patients after 180 days of sensor wear (â0.43% ± 0.69%, 5 ± 8 mmol/mol, P < 0.0001). As expected, CGM-naĂŻve patients achieved the greatest reduction in HbA1c (â0.74% ± 0.48%, 8 ± 5 mmol/mol). TIR significantly increased and TAR and mean daily sensor glucose significantly decreased while TBR did not change after 180 days of sensor wear. Conclusions: Real-world clinical use of the Eversense CGM System for 180 days was associated with significant improvements in HbA1c and CGM metrics among adults with type 1 diabetes. The study is registered on clinicaltrials.gov (NCT04160156)
Reversal of <i>MYB </i>-dependent suppression of <i>MAFB </i>expression overrides leukaemia phenotype in MLL-rearranged AML
Abstract The transcription factor MYB plays a pivotal role in haematopoietic homoeostasis and its aberrant expression is involved in the genesis and maintenance of acute myeloid leukaemia (AML). We have previously demonstrated that not all AML subtypes display the same dependency on MYB expression and that such variability is dictated by the nature of the driver mutation. However, whether this difference in MYB dependency is a general trend in AML remains to be further elucidated. Here, we investigate the role of MYB in human leukaemia by performing siRNA-mediated knock-down in cell line models of AML with different driver lesions. We show that the characteristic reduction in proliferation and the concomitant induction of myeloid differentiation that is observed in MLL-rearranged and t(8;21) leukaemias upon MYB suppression is not seen in AML cells with a complex karyotype. Transcriptome analyses revealed that MYB ablation produces consensual increase of MAFB expression in MYB-dependent cells and, interestingly, the ectopic expression of MAFB could phenocopy the effect of MYB suppression. Accordingly, in silico stratification analyses of molecular data from AML patients revealed a reciprocal relationship between MYB and MAFB expression, highlighting a novel biological interconnection between these two factors in AML and supporting new rationales of MAFB targeting in MLL-rearranged leukaemias
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