2,423 research outputs found

    Intertwined Rashba, Dirac and Weyl Fermions in Hexagonal Hyperferroelectrics

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    By means of density functional theory based calculations, we study the role of spin-orbit coupling in the new family of ABC hyperferroelectrics [Phys. Rev. Lett. 112, 127601 (2014)]. We unveil an extremely rich physics strongly linked to ferroelectric properties, ranging from the electric control of bulk Rashba effect to the existence of a three dimensional topological insulator phase, with concomitant topological surface states even in the ultrathin film limit. Moreover, we predict that the topological transition, as induced by alloying, is followed by a Weyl semi-metal phase of finite concentration extension, which is robust against disorder, putting forward hyperferroelectrics as promising candidates for spin-orbitronic applications.Comment: 5 pages, 3 figure

    Definition of an On-Board Comfort Index (Rail) for the Railway Transport

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    The use of collective transport is strongly influenced by the quality of offered service. One of the overriding factors that affect the modal shift process is the quality of transport systems. To increase the attractiveness of collective transport services and therefore reduce the use of cars, authorities in collaboration with transport companies should take steps to ensure a high level of service quality in the public transport system. The provided quality is the level of quality achieved on daily basis and measured by the customer/user point of view. This research aims to relate service quality perceived by the user to measurements of two environmental indicators, that is, vibration, in reference to which the acceleration transmitted to the body by the vehicle motion and by its vibration will be measured, and noise, in reference to which the Equivalent Sound Pressure Level—Leq (A)—will be measured. Finally, a Comfort Index (CI) (rail) is specified, calibrated, and validated

    CT perfusion in patients with lung cancer: Squamous cell Carcinoma and Adenocarcinoma show a different Blood Flow

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    Objectives. To characterize tumour baseline blood flow (BF) in two lung cancer subtypes, adenocarcinoma (AC) and squamous cell carcinoma (SCC), also investigating those \u201cborderline\u201d cases whose perfusion value is closer to the group mean of the other histotype. Materials and Methods. 26 patients (age range 36-81 years) with primary Non-Small Cell Lung Cancer (NSCLC), subdivided into 19 AC and 7 SCC, were enrolled in this study and underwent a CT perfusion, at diagnosis. BF values were computed according to the maximum-slope method and unreliable values (e.g., arising from artefacts or vessels) were automatically removed. The one-tail Welch\u2019s t-test (p-value < 0.05) was employed for statistical assessment. Results. At diagnosis, mean BF values (in [mL/min/100g]) of AC group [(83.5 \ub1 29.4)] are significantly greater than those of SCC subtype [(57.0 \ub1 27.2)] (p-value = 0.02). However, two central SCCs undergoing artefacts from vena cava and pulmonary artery have an artificially increased mean BF. Conclusions. The different hemodynamic behaviour of AC and SCC should be considered as a biomarker supporting treatment planning to select the patients, mainly with AC, that would most benefit from antiangiogenic therapies. The significance of results was achieved by automatically detecting and excluding artefactual BF values

    Resistance to Ralstonia Solanacearum of sexual hybrids between Solanum commersonii and S. tuberosum

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    This research was carried out to study the levels of bacterial wilt resistance and genetic diversity of (near) pentaploid sexual hybrids between S. commersonii (2n = 2x = 24, 1EBN) and cultivated S. tuberosum. Following artificial inoculations with Ralstonia solanacearum, wilting degree was estimated on a scale from 0 to 4, and seven genotypes of 26 (27%) displaying a S. commersonii like behavior were identified. Latent bacterial colonizations were detected in roots of symptomless S. commersonii and hybrids, whereas no bacterial populations were detected within stems. This suggests that the movement and/or growth of the bacterium in the aerial part were strongly inhibited. A molecular study with AFLP markers clustered hybrids into nine groups and provided evidence that resistant hybrids were slightly more similar to cultivated S. tuberosum than to the wild parent. This is important in view of the re-establishment of the cultivated genetic background through backcrosses. Hybrids displayed good fertility and are being used for further breeding efforts

    Intranasal rapamycin ameliorates Alzheimer-like cognitive decline in a mouse model of Down syndrome

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    Background: Down syndrome (DS) individuals, by the age of 40s, are at increased risk to develop Alzheimer-like dementia, with deposition in brain of senile plaques and neurofibrillary tangles. Our laboratory recently demonstrated the disturbance of PI3K/AKT/mTOR axis in DS brain, prior and after the development of Alzheimer Disease (AD). The aberrant modulation of the mTOR signalling in DS and AD age-related cognitive decline affects crucial neuronal pathways, including insulin signaling and autophagy, involved in pathology onset and progression. Within this context, the therapeutic use of mTOR-inhibitors may prevent/attenuate the neurodegenerative phenomena. By our work we aimed to rescue mTOR signalling in DS mice by a novel rapamycin intranasal administration protocol (InRapa) that maximizes brain delivery and reduce systemic side effects. Methods: Ts65Dn mice were administered with InRapa for 12 weeks, starting at 6 months of age demonstrating, at the end of the treatment by radial arms maze and novel object recognition testing, rescued cognition. Results: The analysis of mTOR signalling, after InRapa, demonstrated in Ts65Dn mice hippocampus the inhibition of mTOR (reduced to physiological levels), which led, through the rescue of autophagy and insulin signalling, to reduced APP levels, APP processing and APP metabolites production, as well as, to reduced tau hyperphosphorylation. In addition, a reduction of oxidative stress markers was also observed. Discussion: These findings demonstrate that chronic InRapa administration is able to exert a neuroprotective effect on Ts65Dn hippocampus by reducing AD pathological hallmarks and by restoring protein homeostasis, thus ultimately resulting in improved cognition. Results are discussed in term of a potential novel targeted therapeutic approach to reduce cognitive decline and AD-like neuropathology in DS individuals

    comfort index ci bus a methodology to measure the comfort on board

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    Abstract The presented work deals with the important topic of assessing the quality of public transport services. This research specifically addresses the performance of the service in terms of comfort. In particular, the study focuses on the definition of a comfort index (CI) that takes into account two dimensions (noise and vibration) measured on board the buses studied, both during motion and on a stationary vehicle. The methodology interprets how users perceive the comfort on board the public transport considered, with numerical data coming from high-precision measuring instruments. This methodology represents a further element of synthesis in the complex quantification of perceptions by an individual, precisely because of the extreme subjectivity of judgment

    The Primacy of High b-Value 3T-DWI Radiomics in the Prediction of Clinically Significant Prostate Cancer

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    Predicting clinically significant prostate cancer (csPCa) is crucial in PCa management. 3T-magnetic resonance (MR) systems may have a novel role in quantitative imaging and early csPCa prediction, accordingly. In this study, we develop a radiomic model for predicting csPCa based solely on native b2000 diffusion weighted imaging (DWIb2000) and debate the effectiveness of apparent diffusion coefficient (ADC) in the same task. In total, 105 patients were retrospectively enrolled between January–November 2020, with confirmed csPCa or ncsPCa based on biopsy. DWIb2000 and ADC images acquired with a 3T-MRI were analyzed by computing 84 local first-order radiomic features (RFs). Two predictive models were built based on DWIb2000 and ADC, separately. Relevant RFs were selected through LASSO, a support vector machine (SVM) classifier was trained using repeated 3-fold cross validation (CV) and validated on a holdout set. The SVM models rely on a single couple of uncorrelated RFs (ρ < 0.15) selected through Wilcoxon rank-sum test (p ≤ 0.05) with Holm–Bonferroni correction. On the holdout set, while the ADC model yielded AUC = 0.76 (95% CI, 0.63–0.96), the DWIb2000 model reached AUC = 0.84 (95% CI, 0.63–0.90), with specificity = 75%, sensitivity = 90%, and informedness = 0.65. This study establishes the primary role of 3T-DWIb2000 in PCa quantitative analyses, whilst ADC can remain the leading sequence for detection
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