The spin-double refraction in two-dimensional electron gas

We briefly review the phenomenon of the spin-double refraction that originates at an interface separating a two-dimensional electron gas with Rashba spin-orbit coupling from a one without. We demonstrate how this phenomenon in semiconductor heterostructures can produce and control a spin-polarized current without ferromagnetic leads

Radiological evaluation of biomarkers for renal cell carcinoma

Role of MRI DWI sequences in the evaluation of early response to neo- angiogenesis inhibitors in metastatic renal cell carcinoma Purpose: Angiogenesis inhibitors have a potential role in treating metastatic renal cell carcinoma, but it is still not clear why some patients don't respond. Our objective was to look for DWI parameters able to identify patients with metastatic renal cell carcinoma who would not benefit from target therapy. RECIST1.1 was considered as Reference Standard. Methods & Materials: We prospectively enrolled 43 patients candidate to start angiogenesis inhibitors with at least one target lesion and who underwent 1,5T MRI examination with multiple bvalues DWI sequences (0,40,200,300,600): one week before (t0), 2 weeks after (t2) and 8 weeks (t8) after treatment beginning. ADC value was calculated drawing ROIs on 3 different planes. 33 patients with 38 lesions had suitable data for comparative evaluation. Results: At T8 follow-up 9 patients had partial response (PR), 20 table disease (SD), 4 progression disease (PD); average progression free survival was 272 days. PD group, as compared to DC or to PR showed significantly lower ADC values at b40 at t0 (p<0.05): we can assess that more vascularised lesions are more responsive to treatment. PD group have significantly lower ADC values then both other groups, at t0, t2 and t8, for all b-values (p<0.05). PFS and OS correlates well with ADC, in particular OS with ADC b40 at t0 (r=0,69). Coclusions: Results show that PD group has significantly lower ADC values than PR or DC everytime (t0, t2, t8) At t0 there is a better correlation between PFS or OS & ADC than PFS & dimensional criteria. ADC at t0 may help selecting patients with promising good response to angiogenesis inhibitors. Moreover at t0 and at t2 ADC has the potential to select patients who wouldn't benefit from angiogenesis inhibitors Nowadays, in the era of target therapy, it is crucial to select patients potentially responders. We have to look at cost/benefit ratio and at increasing costs of treatment options. DWI has the potential role to identify patients whose's tumor wouldn't benefit from target therapy, adding a value (ADC) to other imaging (e.g. DCE-MRI, texture imaging) and clinical parameters (e.g. miRNA) in a hypothetic multiparametric analysis.CT Texture Analysis in Clear Cell Renal Cell Carcinoma: a Radiogenomics Prospective Purpose: The aim of this study was to investigate whether quantitative parameters obtained from CT Texture Analysis (CTTA) correlate with expression of miRNA in clear cell Renal Cell Carcinoma (ccRCC). Methods and Materials: In a retrospective single centre study, multiphasic CT examination (with arterial, portal, equilibrium and urographic phases) was performed on 20 patients with clear cell renal carcinomas (14 men and 6 women; mean age 65 years ± 13). Measures of heterogeneity were obtained in post-processing by placing a ROI on the entire tumour and CTTA parameters such as entropy, kurtosis, skewness, mean, mean of positive pixels, and SD of pixel distribution histogram were measured using multiple filter settings. Quantitative data were correlated with the expression of miRNAs obtained from the same cohort of patients: 8 fresh frozen samples and 12 formalin-fixed paraffin-embedded samples (miR-21-5p, miR-210-3p, miR-185-5p, miR-221-3p, miR-145-5p). Both evaluations (miRNAs and CTTA) were performed on tumour tissues as well as on normal cortico-medullar tissues. Analysis of Variance with linear multiple regression model methods were obtained with SPSS statistic software. For all comparisons, statistical significance was assumed p<0.05 Results: We evidenced that CTTA has robust parameters (e.g. entropy, mean, sd) to distinguish normal from pathological tissues. Moreover, a higher coefficient of determination between entropy and miR-21-5p expression (R2 =0,25) was evidenced in tumour tissues as compared to normal tissues (R2 =0,15). Interestingly, excluding four patients with extreme over-expression of miR-21-5p, excellent relation between entropy and miR21-5p levels was found specifically in tumour samples (R2= 0,64; p<0.05). Conclusion: Entropy and miRNA-21-5p show promising correlation in ccRCC; in addiction CTTA features, in particular mean and entropy show a statistically significant increase in ccRCC as compared with normal renal parenchyma

Verlinde bundles of families of hypersurfaces and their jumping lines

Verlinde bundles are vector bundles $V_k$ arising as the direct image $\pi_*(\mathcal L^{\otimes k})$ of polarizations of a proper family of schemes $\pi\colon \mathfrak X \to S$. We study the splitting behavior of Verlinde bundles in the case where $\pi$ is the universal family $\mathfrak X \to |\mathcal O(d)|$ of hypersurfaces of degree $d$ in $\mathbb P^n$ and calculate the cohomology class of the locus of jumping lines of the Verlinde bundles $V_{d+1}$ in the cases $n=2,3$.Comment: This version adds a missing definition in Prop. 2.2 and corrects minor typo

Bank ownership and performance in China: some further evidence

China has recently completed an important part of the reform process of its banking system partially privatising its major Commercial banks with both domestic and foreign capital. This paper investigates the effect of different ownership structures to banks’ economic performance, using a panel data analysis of 57 banks over the 2000-2016 period. A specific focus will be given to the Big-Five Commercial banks and the role of foreign ownership. The main findings show that private domestic banks are the most efficient and profitable banks; on the opposite side, Policy banks are by far the least efficient and profitable banks; Big Five banks have instead closed the cost efficiency and Asset quality gap with the best performing private banks, while profitability findings remain mixed. Also, strategic minority foreign ownership in State-owned banks is found to be positively associated with bank performance

Stochastic dynamics for a single vibrational mode in molecular junctions

We propose a very accurate computational scheme for the dynamics of a classical oscillator coupled to a molecular junction driven by a finite bias, including the finite mass effect. We focus on two minimal models for the molecular junction: Anderson-Holstein (AH) and two-site Su-Schrieffer-Heeger (SSH) models. As concerns the oscillator dynamics, we are able to recover a Langevin equation confirming what found by other authors with different approaches and assessing that quantum effects come from the electronic subsystem only. Solving numerically the stochastic equation, we study the position and velocity distribution probabilities of the oscillator and the electronic transport properties at arbitrary values of electron-oscillator interaction, gate and bias voltages. The range of validity of the adiabatic approximation is established in a systematic way by analyzing the behaviour of the kinetic energy of the oscillator. Due to the dynamical fluctuations, at intermediate bias voltages, the velocity distributions deviate from a gaussian shape and the average kinetic energy shows a non monotonic behaviour. In this same regime of parameters, the dynamical effects favour the conduction far from electronic resonances where small currents are observed in the infinite mass approximation. These effects are enhanced in the two-site SSH model due to the presence of the intermolecular hopping t. Remarkably, for sufficiently large hopping with respect to tunneling on the molecule, small interaction strengths and at intermediate bias (non gaussian regime), we point out a correspondence between the minima of the kinetic energy and the maxima of the dynamical conductance.Comment: 19 pages, 16 figures, submitted to Physical Review

Ballistic transport in one-dimensional loops with Rashba and Dresselhaus spin-orbit coupling

We discuss the combined effect of Rashba and Dresselhaus spin-orbit interactions in polygonal loops formed by quantum wires, when the electron are injected in a node and collected at the opposite one. The conditions that allow perfect localization are found. Furthermore, we investigate the suppression of the Al'tshuler--Aronov--Spivak oscillations that appear, in presence of a magnetic flux, when the electrons are injected and collected at the same node. Finally, we point out that a recent realization of a ballistic spin interferometer can be used to obtain a reliable estimate of the magnitude ratio of the two spin-orbit interactions.\bigskipComment: 6 figure

Classifying one-dimensional discrete models with maximum likelihood degree one

We propose a classification of all one-dimensional discrete statistical models with maximum likelihood degree one based on their rational parametrization. We show how all such models can be constructed from members of a smaller class of 'fundamental models' using a finite number of simple operations. We introduce 'chipsplitting games', a class of combinatorial games on a grid which we use to represent fundamental models. This combinatorial perspective enables us to show that there are only finitely many fundamental models in the probability simplex $\Delta_n$ for $n\leq 4$.Comment: 34 pages. New version is shorter and focuses on the essentia