Search

Flow intensity represents an important input to be investigated in the ship propeller jet scouring process in ship maneuvering areas, waterways path, and mooring in navigation channels. Although the still water condition is not realistic, since it induces modifications in the canonical propeller jet scouring process in waterways, several studies were based on this assumption and only a few papers focused on the influence of the flow intensity are present in the technical literature. In this work, an experimental campaign aimed at exploring the flow intensity effects on the propeller jet and related scour was carried out. In particular, three flow intensities combined with different propeller submergence depths were tested. The experimental results are shown in terms of longitudinal and cross-sectional scoured bed profiles, and empirical equations to compute the main scour hole dimensions are proposed. Moreover, scour hole bathymetries were analyzed by spectral analysis to estimate characteristics length scales. In order to increase the detail on the fluid mechanics analysis to explain the influence of the flow intensity on the evolution of the scour hole and obtain an insight into the influence of the boundary effect on the flow field, Reynolds-Averaged Navier–Stokes simulations were performed over the three-dimensional scoured bathymetry, acquired at the equilibrium stage, and over the horizontal boundary, representing the earliest stages of the scouring process. The good agreement between the numerical results and the measured velocities at the equilibrium stage allowed also the simulations over a flat bed in the same hydraulic conditions. These represent the beginning of the scour process in the case in which the propeller blades are close to the bottom. As to the authors' knowledge, the last configurations were never simulated before, owing to the difficulties in managing the computation of a moving mesh close to a solid boundary. The results show, for the first time numerically, the plane boundary effects on the characteristics of propeller jets with and without an incoming flow. [ABSTRACT FROM AUTHOR]

Background: Fingolimod (FTY) induces sequestration of lymphocytes in secondary lymphoid organs and the average lymphocyte recovery following discontinuation takes 1–2 months. It has been hypothesized that the therapeutic effects of subsequent cell-depleting agents may be compromised if initiated before lymphocyte recovery has occurred. Objective: To assess the risk of relapses following FTY discontinuation and the initiation of a B/T cell-depleting agent in relation to washout duration using data from the Italian MS Register. Methods: The risk of relapses was assessed in relation to different washout durations (< 6, 6–11, 12–17 and > / = 18 weeks) in patients starting alemtuzumab, rituximab, ocrelizumab or cladribine following FTY discontinuation. Results: We included 329 patients in the analysis (226F, 103 M; mean age 41 ± 10 years). During the cell-depleting treatment, the incidence rate ratio for a relapse was significantly greater in patients with a washout period of 12–17 and > / = 18 weeks compared to the reference period (< 6 weeks). The risk of a relapse was significantly influenced by the occurrence of relapses during FTY treatment and by washout length, with hazard ratios markedly increasing with the washout duration. Conclusion: The risk of relapses increases with the washout duration when switching from FTY to lymphocyte-depleting agents. [ABSTRACT FROM AUTHOR]

Introduction: Conversion Total Hip Arthroplasty (cTHA) is a rescue strategy for proximal femur osteosynthesis failures. However, it is unclear whether cTHAs performed for extra-capsular fracture fixation failures (ECF) or for intra-capsular fracture fixation failures (ICF) share the same complexity and efficacy. The purpose of our study was to compare cTHAs performed on pre-existing ICFs and pre-existing ECFs, focusing on surgical complications and functional outcomes in both groups.Methods: An observational retrospective study was conducted on cTHA patients, treated between 2014 and 2018, divided into 2 groups: ICF-group and ECF-group. The main outcomes were: type of implant used, duration of surgery, need for transfusions, incidence of complications, functional outcomes.Results: 28 patients were included (15 in the ECF group and 13 in the ICF group); the average follow-up was of 31 ± 17.3 months. No significant differences were identified in terms of the type of implant used and duration of surgery. The number of transfused patients was 4 in the ICF group and 12 in the ECF group (p = 0.02); the average transfused units were 0.4 ± 0.7 in the ICF group and 1.3 ± 0.9 in the ECF group (p = 0.01). The incidence of complications - an infection and a dislocation, both of which occurred in the ICF group - and functional outcomes did not present significant differences.Conclusion: The conversion surgery on ECFs patients is technically more difficult for the surgeon and prone to greater blood loss. The outcomes are satisfactory and overlap between the two groups. [ABSTRACT FROM AUTHOR]

A ship propeller jet causes bed scouring and deposition of sediments around the scoured area. Although the bed topography changes induced by the ship propeller are one of the main issues in a harbor, these effects are relevant in other contexts concerning the ship maneuvering zone. An unexplored problem is the scour induced by the propeller jet in waterways. In this case, the still water condition, commonly accepted in several research studies, is not justifiable owing to the effect of an additional flow to the propeller jet, which can induce alterations in the scouring process. Thus, in this paper, an experimental campaign on the combined effects of a propeller jet and a uniform flow on a mobile bed is presented. Specifically, different propeller submergence depths and water discharges were tested. Numerical simulations were performed to highlight the different behaviors observed in the experimental runs with and without a uniform flow in addition to the propeller swirling jet. Furthermore, the presence of the channel flow was investigated in terms of scoured longitudinal and transverse bed profiles, as well as of the entire scour hole bathymetry. A regression equation was obtained to compute the maximum scour depths and the scoured volume for the investigated conditions. Finally, a spectral analysis method is proposed to characterize the complex bed bathymetry induced by the propeller jet and the uniform flow. [ABSTRACT FROM AUTHOR]

We study the quantum fluctuations of the two quadratures of the emitted electromagnetic radiation generated by a quantum Hall device in a quantum point contact geometry. In particular, we focus our attention on the role played by the unavoidable electron–electron interactions between the two edge channels at filling factor two. We investigate quantum features of the emitted microwave radiation, such as squeezing, by studying the current fluctuations at finite frequency, accessible through a two-filters set-up placed just after the quantum point contact. We compare two different drives, respectively a cosine and a train of Lorentzian pulses, used for the injection of the excitations into the system. In both cases quantum features are reduced due to the interactions, however the Lorentzian drive is still characterized by a robust squeezing effect which can have important application on quantum information. [ABSTRACT FROM AUTHOR]

Droplet microfluidics is widespread in many chemical and biological applications where each droplet can be considered as a single, independent reactor unaffected by the presence of channel walls. This compartmentalization is facilitated by the addition of surfactants to increase the emulsion stability. However, the presence of surfactants is expected to strongly affect the dynamics and shape of flowing droplets. We report a systematic experimental study of the curvature of the front and the rear menisci of confined droplets flowing in a circular channel, with and without surfactants. In detail, the role played by surfactants on the droplet shape is investigated by dispersing them either in the droplet or in the continuous phases. The curvatures are evaluated by varying droplet speed, interfacial tension, and surfactant concentration. The curvature of the droplet front is found to scale with the capillary number (Ca) regardless of the presence or absence of surfactants. Differently, the curvature of the rear meniscus strongly depends on the surfactant concentration and whether surfactants are dispersed in the droplet or continuous phases. The surfactant accumulation at concentrations higher than the critical micelle concentration leads to an unexpected increase in the curvature in the former case and to droplet breakup in the latter. [ABSTRACT FROM AUTHOR]

Background and purpose: Cerebrospinal fluid (CSF) kappa free light chains (FLCs) may be a more sensitive marker of intrathecal immunoglobulin (Ig)G synthesis compared with oligoclonal bands (OCBs). Our aim was to retrospectively determine the additional value of the kappa and lambda index (CSF FLC/serum FLC)/(CSF albumin/serum albumin) in predicting a multiple sclerosis (MS) diagnosis in a group of OCB‐negative patients with suspected MS. Methods: The CSF and serum kappa and lambda FLCs were tested using the Freelite kit (serum) and Freelite Mx (CSF) assay (The Binding Site Group, Bimingham, UK) in 391 OCB‐negative patients with suspected/possible MS and in 54 OCB‐positive patients with MS. Results: The CSF kappa FLC levels were below the detection limit (0.27 mg/L) in 61% of patients. Using quantitative data, we found the best kappa index cut‐off value for the prediction of MS to be 5.8. A kappa index ≥5.8 was present in 25% of OCB‐negative MS (23/92) and in 98% of OCB‐positive patients with MS. Using a qualitative approach and a kappa index cut‐off of 5.9, based on literature data, we likewise found that 24% of OCB‐negative patients with MS had a kappa index ≥5.9, compared with 5.4% of OCB‐negative patients without MS (P < 0.001). No reliable data could be obtained for the lambda index; lambda FLCs were below the detection limit (0.68 mg/L) in 90% of CSF samples. Conclusions: The kappa index could contribute to the identification of OCB‐negative patients with a high probability of an MS diagnosis. Using more sensitive techniques might even improve the diagnostic performance of the kappa index and better define the role of the lambda index. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the recovery cycle of somatosensory evoked potentials (SEPs) in children with migraine without aura before and after treatment with topiramate. Eleven migraine children were studied before and after a 3-month treatment with topiramate at the average dose of 1.3 mg/kg/day. We calculated the SEP latency and amplitude modifications after paired electrical stimuli at 5, 20 and 40 ms interstimulus intervals, comparing them with a single stimulus condition assumed as baseline. In nine patients, who had a significant reduction in headache frequency after treatment, the recovery cycles of the P24 (P ¼ 0.03) and N30 (P < 0.005) potentials were longer after than before topiramate treatment. In two migraineurs who did not show any improvement, the recovery cycles of the cortical SEP components were even shorter after treatment. Our results suggest that topiramate efficacy in paediatric migraine prophylaxis is probably related to restored cortical excitability. [ABSTRACT FROM AUTHOR]

The present work aims at studying the turbulence structure developed over a highly rough bed in open-channel flows (OCFs) by varying the relative submergence through the use of three sediment sizes ranging from gravels to pebbles. The second-order moments were analyzed and compared with those already observed for canonical turbulent OCFs having similar values of relative submergence. Particular attention was paid to the turbulent Reynolds stresses, and the viscous and the form-induced shear stresses in the near bed region. The violation of the Taylor hypothesis was verified through an alternative method, by comparing two time scales, namely, the large scale advection time and the eddy characteristic nonlinear time. Moreover, an analysis of the large eddies was performed with the spectral analysis. The premultiplied spectra provide a way to quantify the contribution of different eddy scales (peaks in the premultiplied spectra) and indicate wavelengths in which a significant amount of energy resides. In order to locate the normalized wavelengths associated with the peaks in the premultiplied spectra, a systematic procedure is presented. [ABSTRACT FROM AUTHOR]

The turbulent flow in natural rough beds is a complex subject, still poorly understood despite the longstanding effort of several researchers. In the present work, a turbulent open-channel flow experiment, with a pebble bed at Reynolds and Froude numbers, respectively, Re = 4.65 × 104 and Fr = 0.186, has been simulated using the Large-Eddy Simulation (LES) technique, in which the wall-adapting local eddy viscosity subgrid scale closure model is used and in the presence of an air-water interface to take into account the effects of the interface deformation in the flow turbulence statistics under a low relative submergence condition. The simulations have been compared with a companion experiment, where the channel bottom is constituted by four pebble layers. For the simulations, the pebble-bed surface has been captured with a high-resolution three-dimensional laser scanner and used to morphologically characterize the numerical channel bottom. Results are presented in terms of turbulence statistics and turbulent laws, showing a good agreement with those obtained in the experiment. Since a good convergence between simulation and experimental results was obtained, the LES dataset was used to compute the Turbulent Kinetic Energy (TKE) dissipation rate across the water depth. The mesh resolution allows showing a detailed TKE dissipation rate distribution across the water depth. Moreover, the equilibrium between TKE production and dissipation was checked to verify the overlap layer existence under low relative submergence condition. Finally, a new procedure for vortex-visualization is implemented, based on the relationship between the vorticity and the TKE dissipation rate. [ABSTRACT FROM AUTHOR]

Droplet microfluidics is a powerful technology that finds many applications in chemistry and biomedicine. Among different configurations, droplets confined in a capillary (or plugs) present a number of advantages: they allow positional identification and simplify the integration of complex multi-steps protocols. However, these protocols rely on the control of droplet speed, which is affected by a complex and still debated interplay of various physico-chemical parameters like droplet length, viscosity ratio between droplets and carrier fluid, flow rate and interfacial tension. We present here a systematic investigation of the droplet speed as a function of their length and interfacial tension, and propose a novel, simple and robust methodology to control the relative distance between consecutive droplets flowing in microfluidic channels through the addition of surfactants either into the dispersed and/or into the continuous phases. As a proof of concept application, we present the possibility to accurately trigger in space and time the merging of two confined droplets flowing in a uniform cross-section circular capillary. This approach is further validated by monitoring a conventional enzymatic reaction used to quantify the concentration of H2O2 in a biological sample, showing its potentialities in both continuous and stopped assay methods. [ABSTRACT FROM AUTHOR]

Droplet microfluidics allows the implementation of several biochemical and bioanalytical protocols in microfluidic devices. However, this integration typically requires the use of microfluidic valves, which allow the control of different operations on the same channels network. Unfortunately, the valves commercially available are almost exclusively suitable for-single phase flow, and only one valve system compatible with multi-phase systems has been presented so far in the literature. We present here a new pinch-like valve that withstands high pressures (tested up to 4 bar), allows droplet manipulation and combines the advantages of conventional pinch valves regarding the absence of dead volume, while making negligible the backflow generated (less than 2 nL). The conception and design of the presented valve, based on numerical simulations, is performed by an optimized microfabrication strategy, combining PDMS soft-lithography and 3D printing technologies. The valves had been tested regarding their mechanical stability and proving their capability of allowing droplets passing through them, without any perturbation. Finally, the very small back-flow volume generated during the actuation, has been exploited for various applications in droplets microfluidics, like droplet handling, droplet-on-demand generation and sorting. [ABSTRACT FROM AUTHOR]

Anecdotal reports suggest that patients with chronic hepatitis C virus ( HCV) hepatitis and overt or occult hepatitis B virus ( HBV) coinfection may reactivate HBV when HCV is suppressed or cleared by direct-acting antivirals ( DAAs). We assessed the prevalence of overt or previous HBV coinfection and the risk of HBV reactivation in patients with HCV cirrhosis treated with DAAs. This was a retrospective cohort of 104 consecutive patients with HCV cirrhosis treated with DAAs. Serum HCV- RNA and HBV- DNA were tested at weeks 4, 8 and 12 of DAAs therapy and at week 12 of follow-up. At the start of DAAs, eight patients (7.7%) were HBsAg positive/ HBeAg negative with undetectable HBV- DNA and low levels of quantitative HBsAg (four on nucleos(t)ide analogues [ NUCs] and four inactive carriers), 37 patients (35.6%) had markers of previous HBV infection (25 anti- HBc positive, 12 anti- HBc/anti- HBs positive) and 59 (56.7%) had no evidence of HBV infection. Sixty-seven patients (64.4%) were HCV- RNA negative at week 4 and 98 (94.2%) achieved sustained virological response. All four HBsAg-positive patients treated with NUCs remained HBV- DNA negative, but three of four untreated patients showed an increase in HBV- DNA of 2-3 log without a biochemical flare and achieved HBV- DNA suppression when given NUCs. During or after DAAs, by conventional assay, HBV- DNA remained not detectable in all 37 anti- HBc-positive patients but in three of them (8.1%) HBV- DNA became detectable with a highly sensitive PCR. HBV reactivation is likely to occur in untreated HBV/ HCV-coinfected cirrhotic patients when they undergo HCV treatment with DAAs. Pre-emptive therapy with NUCs should be considered in this setting. Anti- HBc-positive patients rarely reactivate HBV without clinical or virological outcomes. [ABSTRACT FROM AUTHOR]

Multiphase and droplet microfluidic systems are growing in relevance in bioanalytical-related fields, especially due to the increased sensitivity, faster reaction times and lower sample/reagent consumption of many of its derived bioassays. Often applied to homogeneous (liquid/liquid) reactions, innovative strategies for the implementation of heterogeneous (typically solid/liquid) processes have recently been proposed. These involve, for example, the extraction and purification of target analytes from complex matrices or the implementation of multi-step protocols requiring efficient washing steps. To achieve this, solid supports such as functionalized particles (micro or nanometric) presenting different physical properties (e.g. magnetic, optical or others) are used for the binding of specific entities. The manipulation of such supports with different microfluidic principles has both led to the miniaturization of existing biomedical protocols and the development of completely new strategies for diagnostics and research. In this review, multiphase and droplet-based microfluidic systems using solid suspensions are presented and discussed with a particular focus on: i) working principles and technological developments of the manipulation strategies and ii) applications, critically discussing the level of maturity of these systems, which can range from initial proofs of concept to real clinical validations. [ABSTRACT FROM AUTHOR]

A correction for the article "The phantom chorus: birdsong boosts human well-being in protected areas", is presented, which is published in the December 16, 2020, issue of the periodical.

Background and purpose To compare two recently developed staging systems for amyotrophic lateral sclerosis ( ALS) [King's College and Milano-Torino staging (MITOS) systems] in an incident, population-based cohort of patients with ALS. Methods Since 2009, a prospective registry has been recording all incident cases of ALS in the Emilia Romagna region in Italy. For each patient, detailed clinical information, including the ALS functional rating scale score, is collected at each follow-up. Results Our study on 545 incident cases confirmed that King's College stages occurred at predictable times and were quite evenly spaced out throughout the disease course (occurring at approximately 40%, 60% and 80% of the disease course), whereas MITOS stages were mostly skewed towards later phases of the disease. In the King's College system there was a decrease in survival and an increase in deaths with escalating stages, whereas in the MITOS system survival curves pertaining to intermediate stages overlapped and the number of deaths was fairly homogenous throughout most stages. Conclusions The King's College staging system had a higher homogeneity (i.e. smaller differences in survival among patients in the same stage) and a higher discriminatory ability (i.e. greater differences in survival among patients in different stages), being more suitable for individualized prognosis and for measuring efficacy of therapeutic interventions. [ABSTRACT FROM AUTHOR]

Purpose: The phase II TACTIC trial prospectively selected patients with KRAS wild-type advanced biliary tract cancer for first-line treatment with panitumumab and combination chemotherapy.Methods: Of 78 patients screened, 85 % had KRAS wild-type tumours and 48 were enrolled. Participants received cisplatin 25 mg/m(2) and gemcitabine 1000 mg/m(2) on day 1 and day 8 of each 21-day cycle and panitumumab 9 mg/kg on day 1 of each cycle. Treatment was continued until disease progression, unacceptable toxicity, or request to discontinue. The primary endpoint was the clinical benefit rate (CBR) at 12 weeks (complete response, partial response, or stable disease). CBR of 70 % was considered to be of clinical interest. Secondary outcomes were progression-free survival, time to treatment failure, overall survival, CA19.9 response and safety.Results: Thirty-four patients had a clinical benefit at 12 weeks, an actuarial rate of 80 % (95 % CI 65-89 %). 46 % had a complete or partial response. Median progression-free survival was 8.0 months (95 % CI 5.1-9.9) and median overall survival 11.9 months (95 % CI 7.4-15.8). Infection accounted for 27 % of the grade 3 or 4 toxicity, with rash (13 %), fatigue (13 %), and hypomagnesemia (10 %) among the more common grade 3 or 4 non-haematological toxicities.Conclusion: A marker-driven approach to patient selection was feasible in advanced biliary tract cancer in an Australian population. The combination of panitumumab, gemcitabine, and cisplatin in KRAS wild-type cancers was generally well tolerated and showed promising clinical efficacy. Further exploration of anti-EGFR therapy in a more selected population is warranted. [ABSTRACT FROM AUTHOR]

We present a microfluidic platform that allows undergoing different chemical operations in a nanoliter droplet starting from the colloidal suspension of magnetic iron oxide (γ-Fe2O3) nanoparticles “NPs” (ferrofluid). These operations include: mixing, flocculation, magnetic decantation, colloidal redispersion, washing, surface functionalization, heating and colloidal assembly. To prove the platform capabilities, we produced fluorescent and magnetic nanoassemblies composed of fluorescent silica and magnetic NPs. [ABSTRACT FROM AUTHOR]

Background Chronic telogen effluvium ( CTE), a poorly understood condition, can be confused with or may be a prodrome to female pattern hair loss ( FPHL). The pathogenesis of both is related to follicle cycle shortening and possibly to blood supply changes. Aim To analyze a number of histomorphometric and immunohistochemical findings through vascular endothelial growth factor ( VEGF), Ki-67, and CD31 immunostaining in scalp biopsies of 20 patients with CTE, 17 patients with mild FPHL and 9 controls. Methods Ki-67 index and VEGF optical density were analyzed at the follicular outer sheath using ImageJ software. CD31 microvessel density was assessed by a Chalkley grid. Results Significant follicle miniaturization and higher density of nonanagen follicles were found in FPHL, compared with patients with CTE and controls. Ki-67+ index correlated positively with FPHL histological features. The FPHL group showed the highest VEGF optical density, followed by the CTE and control groups. No differences were found in CD31 microvessel density between the three groups. Conclusions Histomorphometric results establish CTE as a distinct disorder, separate from FPHL from its outset. Its pathogenic mechanisms are also distinct. These findings support the proposed mechanism of 'immediate telogen release' for CTE, leading to cycle synchronization. For FPHL, accelerated anagen follicular mitotic rates and, thus, higher Ki-67 and VEGF values, would leave less time for differentiation, resulting in hair miniaturization. [ABSTRACT FROM AUTHOR]

Quantum Hall edge channels at integer filling factor provide a unique test bench to understand the decoherence and relaxation of single-electron excitations in a ballistic quantum conductor. In this Letter, we obtain a full visualization of the decoherence scenario of energy (Landau)- and time (Levitov)-resolved single-electron excitations at filling factor ν = 2. We show that the Landau excitation exhibits a fast relaxation followed by spin-charge separation whereas the Levitov excitation only experiences spin-charge separation. We finally suggest to use Hong-Ou-Mandel-type experiments to probe specific signatures of these different scenarios. [ABSTRACT FROM AUTHOR]

We investigate the finite frequency (FF) noise properties of edge states in the quantum Hall regime. We consider the measurement scheme of a resonant detector coupled to a quantum point contact in the weak-backscattering limit. A detailed analysis of the difference between the ‘measured’ noise, due to the presence of the resonant detector, and the symmetrized FF noise is presented. We discuss both the Laughlin and Jain sequences, studying the tunnelling excitations in these hierarchical models. We argue that the measured noise can better distinguish between the different excitations in the tunnelling process with respect to the symmetrized FF counterpart in an experimentally relevant range of parameters. Finally, we illustrate the effect of the detector temperature on the sensibility of this measure. [ABSTRACT FROM AUTHOR]

The edge states of a two-dimensional topological insulator are characterized by their helicity, a very remarkable property which is related to the time-reversal symmetry and the topology of the underlying system. We theoretically investigate a Hong-Ou-Mandel-type setup as a tool to probe it. Collisions of two electrons with the same spin show a Pauli dip, analogous to the one obtained in the integer quantum Hall case. Moreover, the collisions between electrons of opposite spin also lead to a dip, known as ℤ2 dip, which is a direct consequence of the constraints imposed by time-reversal symmetry. In contrast to the integer quantum Hall case, the visibility of these dips is reduced by the presence of the additional edge channels, and crucially depends on the properties of the quantum point contact. As a unique feature of this system, we show the possibility of three-electron interference, which leads to a total suppression of the noise independently of the point contact configuration. This is assured by the peculiar interplay between Fermi statistics and topology. This work intends to extend the domain of applicability of electron quantum optics. [ABSTRACT FROM AUTHOR]

Recent electron quantum optics experiments performed with on-demand single electron sources call for a mixed time/frequency approach to electronic quantum coherence. Here, we present a Wigner function representation of first-order electronic coherence and show that it provides a natural visualization of the excitations emitted by recently demonstrated single electron sources. It also gives a unified perspective on single particle and two particle interferometry experiments. In particular, we introduce a nonclassicality criterion for single electron coherence and discuss it in the context of Mach-Zehnder interferometry. Finally, the electronic Hanbury Brown and Twiss and the Hong-Ou-Mandel experiments are interpreted in terms of overlap of Wigner function, thus connecting them to signal processing. [ABSTRACT FROM AUTHOR]

We present a comprehensive study of water drops sliding down chemically heterogeneous surfaces formed by a periodic pattern of alternating hydrophobic and hydrophilic stripes. Drops are found to undergo a stick-slip motion whose average speed is an order of magnitude smaller than that measured on a homogeneous surface having the same static contact angle. This motion is the result of the periodic deformations of the drop interface when crossing the stripes. Numerical simulations confirm this view and are used to elucidate the principles underlying the experimental observations. [ABSTRACT FROM AUTHOR]

We study parametric quantum pumping in a two-dimensional topological insulator bar in the presence of electron interactions described by a helical Luttinger liquid. The pumping current is generated by two point contacts whose tunneling amplitudes are modulated in time. The helical nature of the edge states of the system ensures the generation of a pumped spin current that is determined by interference effects related to spin-flipping or spin-preserving tunneling at the quantum point contacts and which can be controlled by all electrical means. We show that the period of oscillation and the position of the zeros of the spin current depend on the strength of the electron interactions, giving the opportunity to directly extract information about them when measured. [ABSTRACT FROM AUTHOR]

Once stimulated, the epidermal growth factor receptor (EGFR) undergoes self-phosphorylation, which, on the one hand, instigates signaling cascades, and on the other hand, recruits CBL ubiquitin ligases, which mark EGFRs for degradation. Using RNA interference screens, we identified a deubiquitinating enzyme, Cezanne-1, that opposes receptor degradation and enhances EGFR signaling. These functions require the catalytic- and ubiquitin-binding domains of Cezanne-1, and they involve physical interactions and transphosphorylation of Cezanne-1 by EGFR. In line with the ability of Cezanne-1 to augment EGF-induced growth and migration signals, the enzyme is overexpressed in breast cancer. Congruently, the corresponding gene is amplified in approximately one third of mammary tumors, and high transcript levels predict an aggressive disease course. In conclusion, deubiquitination by Cezanne-1 curtails degradation of growth factor receptors, thereby promotes oncogenic growth signals. [ABSTRACT FROM AUTHOR]

We propose a general mechanism for the renormalization of the tunnelling exponents in edge states of the fractional quantum Hall effect. Mutual effects of the coupling with out-of-equilibrium 1/ f noise and dissipation are considered for both the Laughlin sequence and the composite co- and counter-propagating edge states with Abelian or non-Abelian statistics. For states with counter-propagating modes, we demonstrate the robustness of the proposed mechanism in the so-called disorder-dominated phase. Prototypes of these states, such as v = 2/3 and v = 5/2, are discussed in detail, and the rich phenomenology induced by the presence of a noisy environment is presented. The proposed mechanism could help justify the strong renormalizations reported in many experimental observations carried out at low temperatures. We show how environmental effects could affect the relevance of the tunnelling excitations, leading to important implications, in particular for the v = 5/2 case. [ABSTRACT FROM AUTHOR]

We present a detailed analysis of finite-frequency noise for the v = 5/2 fractional quantum Hall state in a quantum point contact geometry. The results were obtained within the Pfaffian and anti-Pfaffian models. We show that the behaviour of the coloured noise allows us to unambiguously discriminate among tunnelling excitations with different charges. Optimal values of the external bias are found in order to emphasize the visibility of the noise peak associated with the tunnelling of a 2-agglomerate, namely an excitation with charge that is double the fundamental one. These correspond to the regime in which the bias is larger than the neutral modes cut-off frequency. The dependence on temperature is also investigated to discriminate between the considered models. [ABSTRACT FROM AUTHOR]

We explain effective charge anomalies recently observed for fractional quantum Hall edge states at v = 5/2 [M. Dolev, Y. Gross, Y.C. Chung, M. Heiblum, V. Umansky, and D. Mahalu, Phys. Rev. B 81, 161303(R) (2010)]. The experimental data of differential conductance and excess noise are fitted, using the anti-Pfaffian model, by properly taking into account renormalizations of the Luttinger parameters induced by the coupling of the system with an intrinsic 1/f noise. We demonstrate that a peculiar agglomerate excitation with charge e/2, double the expected e/4 charge, dominates the transport properties at low energies. [ABSTRACT FROM AUTHOR]

Abstract: We investigate the dynamics of quasiparticle agglomerates in edge states of the Jain sequence for . Comparison of the Fradkin–Lopez model with the Wen one is presented within a field theoretical construction, focusing on similarities and differences. We demonstrate that both models predict the same universal role for the multiple-quasiparticle agglomerates that dominate on single quasiparticles at low energy. This result is induced by the presence of neutral modes with finite velocity and is essential to explain the anomalous behavior of tunneling conductance and noise through a point contact. [Copyright &y& Elsevier]

Monitoring of HCV-RNA in blood during antiviral therapy is performed mostly by commercially available reverse transcription polymerase chain reaction-based (RT-PCR) assays, with a lower detection limit of 30–50 IU/mL of HCV-RNA. Use of different tests in the pivotal trials of combination therapy has generated some discordance, in terms of predictive value of the early virological response (EVR). To evaluate whether the use of a more sensitive test, as a qualitative assay based on transcription mediated amplification (TMA) with a lower detection limit of 5–10 IU/mL of HCV-RNA, may obtain a better prediction of EVR and of the ultimate virological outcome, we retrospectively evaluated serial samples from 108 naïve patients with HCV genotype 1 chronic hepatitis, treated with pegylated α2b interferon plus ribavirin for 48 weeks and with a 24 weeks stopping rule. Serum samples of patients, obtained during treatment at weeks 4, 12, 24 and 48 and after treatment at week 24, were evaluated by TMA. Comparison of the RT-PCR and TMA assays for the qualitative detection of HCV-RNA showed no significant differences in performance when these tests were used at the end of the treatment period for assessing patients without an on-treatment virological response and those who eventually obtain a sustained virological response. Our results show instead that the use of TMA assay to detect HCV-RNA at 12 and 24 weeks of the combination therapy is more effective than RT-PCR in identifying patients with the highest probability of sustained HCV-RNA clearance. [ABSTRACT FROM AUTHOR]

Overexpression of the c-Met/hepatocyte growth factor receptor(HGF-R) proto-oncogene and abnormal generation of intracellular oxygen species (reactive oxygen species (ROS)) have been linked, by independent lines of evidence, to cell transformation and to malignant growth. By comparing two subpopulations of the B16 mouse melanoma (B16-F0 and B16-F10) endowed with different lung metastasis capacities (low and high, respectively) we found that both the expression/phosphorylation of c-Met and the steady-state levels of ROS positively correlated with metastatic growth. shRNA-mediated downregulation of c-Met in F10 cells led to a parallel decrease in the generation of oxygen species and in metastatic capacity, suggesting that oxidants may mediate the pro-metastatic activity of the HGF receptor. c-Met activation by a ligand elicits the formation of oxidant species through the oxidase-coupled small GTPase Rac-1, a relevant downstream target of the HGF-R. Moreover, cell treatment with the catalytic ROS scavengers EUK-134 and EUK-189 attenuates Met signaling to ERKs and inhibits the anchorage-independent growth of F10 cells, consistent with a critical role for oxygen species in HGF signaling and in aggressive cell behavior. Finally, genetic manipulation of the Rac-ROS cascade at different levels demonstrated its crucial role in the pro-metastatic activity of c-Met in vivo. Thus, we have outlined a novel cascade triggered by c-Met and mediated by ROS, linked to metastasis and potentially targetable by new antimetastatic, redox-based therapies.Oncogene (2006) 25, 3689–3698. doi:10.1038/sj.onc.1209409; published online 6 February 2006 [ABSTRACT FROM AUTHOR]

summary. High-dose induction with α-interferon induces early viral clearance of hepatitis C and combined with ribavirin enhances sustained response. We assess whether adding ribavirin after viral clearance obtained by α-interferon induction increased the rate of viral eradication.Forty-one naïve patients with chronic hepatitis C were randomised to receive, after 4 weeks of 10 mU daily of α-interferon (induction), 3 mU daily for 22 weeks and 3 mU thrice weekly for 26 weeks of either interferon alone (monotherapy) or interferon plus 1000–1200 mg daily of ribavirin (combination therapy). At the end of the induction phase, 23 (56%) subjects had cleared HCV-RNA. During therapy, breakthrough was observed in four patients on monotherapy, but never in patients on combination therapy. The rate of clearance of HCV-RNA was different between monotherapy and combination therapy at the end of treatment (40% vs. 76.1%, P= 0.02) and at the end of follow-up (5% vs. 57.1%, P =0.001). Twelve of the 23 patients who cleared HCV-RNA during induction, but only one of the 18 still HCV-RNA-positive after 4 weeks of therapy, had a sustained response (52.2% vs. 5.6%, P =0.001). Clearance of HCV-RNA at 1 week had a high positive predictive value for sustained response in combination therapy (PPV=0.75), but not in monotherapy (PPV=0.33). Induction with high daily doses of α-interferon obtains suppression of hepatitis C in more than half of patients, but ribavirin is needed to maintain a sustained response. The rate of sustained response is a function of the time to HCV-RNA clearance. In patients not responding to induction therapy addition of ribavirin does not obtain a sustained virological response. [ABSTRACT FROM AUTHOR]

In the past 20 years, droplet microfluidics is burgeoning in many chemical and biological applications due to the unique capability of droplets to act as confined containers. Confinement is ensured even in the case of squeezed droplets within microchannels much smaller than droplet volumes due to the presence of a lubrication thin film that prevents contact between droplets and the channel walls. The thickness of the lubrication film depends on the dynamics of the entire microfluidic system, affecting the actual droplet's shape and velocity. Therefore, this film is extensively studied to obtain insight into the dynamics of flowing droplets, especially when confined in small channels. Circular cross section channels are the most studied for their axial symmetry, but practical applications present most likely non-axisymmetric channels, as a result of fabrication processes, such as soft lithographic rectangular channels. The latter showed unique transitional morphological behavior of droplets, which assumes an axisymmetric or non-axisymmetric shape during their flow inside a non-axisymmetric channel, depending on the lubrication film. This work gives a comprehensive experimental characterization of the dynamics of the lubrication film during the droplet shape transition. We settled on a novel approach based on the optical diffraction of a localized light beam provided by two-facing optical waveguides integrated with the microfluidics circuit. The technique allows for studying the dynamics of flowing droplets and their relationship with the lubrication film thickness. Additionally, this experimental system enables a precise definition of two regimes of lubrication film, and the critical capillary number at which the transition occurs. [ABSTRACT FROM AUTHOR]

The prevalence of trigeminal neuralgia (TN) in patients with Multiple Sclerosis (MS) is higher than in the general population and its management can be particularly challenging due to a number of reasons including high recurrence rates, lack of MS-specific treatment guidelines and uncertainties about pain pathophysiology. Aim of this cross-sectional, multicentre survey was to gather information on the current treatment modalities and options of MS-related TN across 23 Italian MS centres. Initial medical management (carbamazepine or oxcarbazepine) of MS-related TN was fairly homogeneous throughout Italian centres. The most commonly available surgical procedure was microvascular decompression, but the frequency and types of surgical procedures available locally differed considerably throughout MS centers, and were unavailable in one quarter of them. This survey reveals some of the issues that could hamper an optimal patient management and underlines the need for a consensus on MS-related TN to support health-care professionals in their approach to this challenging condition and to facilitate the development of local guidelines aimed at ensuring equity in access to care and treatment optimization. • Multiple Sclerosis (MS)-related trigeminal neuralgia (TN) management is challenging. • MS-related TN treatment guidelines are lacking. • There are considerable differences amongst Italian centres in the surgical options available locally. [ABSTRACT FROM AUTHOR]

A correction is presented to the article "The phantom chorus: birdsong boosts human well-being in protected areas'" which appeared in the 2021 issue.

Background and purpose: Dimethyl fumarate (DMF) causes a mean lymphocyte count drop of approximately 30% in relapsing–remitting multiple sclerosis (RRMS) patients. The relationship between this reduction and DMF effectiveness is controversial. The objective was to investigate if the decrease in absolute lymphocyte count (ALC) from baseline during DMF treatment is associated with clinical and magnetic resonance imaging (MRI) disease activity. A secondary aim was to evaluate ALC variations over time in a real‐life cohort of DMF‐treated patients. Methods: Demographic, laboratory, clinical and MRI data were collected in this observational multicentre study, conducted on RRMS patients treated with DMF for at least 6 months. Multivariate Cox models were performed to evaluate the impact of 6‐month ALC drop on time to no evidence of disease activity (NEDA‐3) status loss. NEDA‐3 is defined as absence of clinical relapses, MRI disease activity and confirmed disability progression. Results: In all, 476 patients (312 females, age at DMF start 38.4 ± 9.97 years) were analysed up to 5‐year follow‐up. A greater lymphocyte decrease was associated with a lower risk of NEDA‐3 status loss (hazard ratio 0.87, P = 0.01). A worse outcome in patients with lower ALC drop (<11.5%), compared with higher tertiles (11.5%–40.5% and >40.5%), was observed (P = 0.008). The nadir of ALC drop (−33.6%) and 35% of grade III lymphopaenia cases occurred after 12 months of treatment. Conclusion: A higher lymphocyte count drop at 6 months is related to better outcomes in DMF‐treated patients. A careful ALC monitoring should be pursued up to 24 months of treatment. [ABSTRACT FROM AUTHOR]

Coupling with an external environment inevitably affects the dynamics of a quantum system. Here, we consider how charging performances of a quantum battery, modelled as a two level system, are influenced by the presence of an Ohmic thermal reservoir. The latter is coupled to both longitudinal and transverse spin components of the quantum battery including decoherence and pure dephasing mechanisms. Charging and discharging dynamics of the quantum battery, subjected to a static driving, are obtained exploiting a proper mapping into the so-called spin-boson model. Analytic expressions for the time evolution of the energy stored in the weak coupling regime are presented relying on a systematic weak damping expansion. Here, decoherence and pure dephasing dissipative coupling are discussed in details. We argue that the former results in better charging performances, showing also interesting features reminiscent of the Lamb shift level splitting renormalization induced by the presence of the reservoir. Charging stability is also addressed, by monitoring the energy behaviour after the charging protocol has been switched off. This study presents a general framework to investigate relaxation effects, able to include also non Markovian effects, and it reveals the importance of controlling and, possibly, engineering system-bath coupling in the realization of quantum batteries. [ABSTRACT FROM AUTHOR]

We study the minimal excitations of fractional quantum Hall edges, extending the notion of levitons to interacting systems. Using both perturbative and exact calculations, we show that they arise in response to a Lorentzian potential with quantized flux. They carry an integer charge, thus involving several Laughlin quasiparticles, and leave a Poissonian signature in a Hanbury Brown-Twiss partition noise measurement at low transparency. This makes them readily accessible experimentally, ultimately offering the opportunity to study real-time transport of Abelian and non-Abelian excitations. [ABSTRACT FROM AUTHOR]

Engineering and studying few-electron states in ballistic conductors is a key step towards understanding entanglement in quantum electronic systems. In this Rapid Communication, we introduce the intrinsic two-electron coherence of an electronic source in quantum Hall edge channels and relate it to two-electron wave functions and to current noise in a Hanbury Brown-Twiss interferometer. Inspired by the analogy with photon quantum optics, we propose to measure the intrinsic two-electron coherence of a source using low-frequency current correlation measurements at the output of a Franson interferometer. To illustrate this protocol, we discuss how it can distinguish between a time-bin-entangled pure state and a statistical mixture of time-shifted electron pairs. [ABSTRACT FROM AUTHOR]

We consider a device which allows one to create and probe single Majorana fermions, in the form of Bogoliubov quasiparticles. It is composed of two counterpropagating edge channels, each put in proximity with a superconducting region where Andreev reflection operates, and which thus converts electrons into Bogoliubov quasiparticles. The edge channels then meet at a quantum point contact where collisions can be achieved. A voltage-biased version of the setup was studied [C. W. J. Beenakker, Phys. Rev. Lett. 112, 070604 (2014)] and showed nonlocal interference phenomena and signatures of Bogoliubov quasiparticle collisions in the high-frequency noise characteristics at the output, constituting an evidence of the Majorana fermion nature of these excitations. Here, voltage-biased leads are replaced by single-electron sources in order to achieve collisions of single Bogoliubov quasiparticles, with the major advantage that zero-frequency noise measurements are sufficient to access the intimate nature of Bogoliubov wave packets. We compute the injection parameters of the source, and go on to investigate the Hanbury-Brown and Twiss and Hong-Ou-Mandel signal at the output, as a function of the mixing angle which controls the electron/hole component of the Bogoliubov wave packet. In particular, information on the internal structure of the Bogoliubov quasiparticle can be recovered when such a quasiparticle collides with a pure electron. Experimental feasibility with singlet or triplet superconductors is discussed. [ABSTRACT FROM AUTHOR]

The article offers the authors' view on early relapses and manifestations of serious diseases in patients with multiple sclerosis (MS) during their treatment with fingolimod (FTY). They mention their administration of the immunomodulating drug to 11 patients between January and October 2012 who were shifted from taking glatiramer acetate due to magnetic resonance imaging (MRI) disease progression. They also provide a hypothesis indicating a decrease in T regulatory cells (Treg) during therapy.

Turbulent flows on highly rough beds, such as those occurring in natural watercourses, represent a longstanding and fascinating problem of hydraulics, motivating in the past few decades huge research on new models of turbulence. In this work, laboratory experiments are presented on a stream flowing on a heterogeneous pebble bed with varying slope. The analysis of the flow speed puts in evidence a clear inertial range, where the Kolmogorov 4/5-law for the streamwise velocity spatial increments holds. The law is used for a systematic estimation of the turbulent kinetic energy dissipation rate ϻ, here measured for three different bed slopes and hence for three different shear Reynolds numbers. The experiments presented here suggest that small scale turbulence has properties similar to the classical picture of homogeneous universal turbulence invoked by the Kolmogorov theory. [ABSTRACT FROM AUTHOR]

Biomimetic surfaces with special wetting properties are attracting a lot of attention because of their fundamental and industrial applications. By tuning surface micro-nano structures and composition, it is possible to fabricate superhydrophobic surfaces exhibiting extreme water repellence and self-cleaning properties like the famous Lotus leaves or strong water adhesion as found on rose petals. Here we report results of a comprehensive study of the static and dynamic wetting properties of hairy surfaces produced by polymer replica molding of porous alumina matrices which are able to pin large water drops. The hairs, which have a characteristic diameter of 80 nm and height between 200 and 600 nm, are fabricated by imprinting an alumina (AAO) stamp into hard poly(dimethylsiloxane) (h-PDMS) and polypropylene (PP) samples. These polymers have similar contact angles for water drops on flat surfaces, but have an elastic modulus that differs by a factor of approximately 100. Hairy surfaces significantly increase drop stickiness with respect to the flat ones for either polymer, with the h-PDMS samples capable of holding water drops about 20% larger than those of the more rigid PP. We also imprinted micropatterned stamps covered by the porous alumina layer to produce multi-scale polymer surfaces consisting of a nanometric hairy layer superposed onto micrometric grooves. Water drops are suspended by the micrometric pillars and the resulting adhesion is intermediate between that on flat and on hairy surfaces. Finally, for nanoimprint with extremely deep AAO pores we saw a complete inversion of drop stickiness to the PP surface: long, collapsed hairs assembled a secondary micrometer scale network exhibiting non-stick hydrophobic wetting properties superior even to the hairy micro-patterned surface. This results in a robust technique to tailor the wetting behavior of polymeric surfaces. [ABSTRACT FROM AUTHOR]

We report the results of extensiveexperimental studies of thesliding of water drops on chemically heterogeneous surfaces formedby square and triangular hydrophobic domains printed on glass surfacesand arranged in various symmetric patterns. Overall, the criticalBond number, that is, the critical dimensionless force needed to depinthe drop, is found to be strongly affected by the shape and the spatialarrangement of the domains. Soon after the droplet begins to move,stick–slip motion is observed on all surfaces, although itis less pronounced than that on striped surfaces. On the triangularpatterns, anisotropic behavior is found with drops sliding down fasterwhen the tips of the glass hydrophilic triangles are pointing in thedown-plane direction. Away from the critical Bond number, the dynamicregime depends mainly on the static contact angle and weakly on theactual surface pattern. Lattice Boltzmann numerical simulations areperformed to validate the experimental results and test the importanceof the viscous ratio between the droplet phase and the outer phase. [ABSTRACT FROM AUTHOR]

We study an electrically controlled quantum spin Hall antidot embedded in a two-dimensional topological insulating bar. Helical edge states around the antidot and along the edges of the bar are tunnel coupled. The close connection between spin and chirality, typical of helical systems, allows to generate a spin-polarized current flowing across the bar. This current is studied as a function of the external voltages, by varying the asymmetry between the barriers. For asymmetric setups, a switching behavior of the spin current is observed as the bias is increased, both in the absence and in the presence of electron interactions. This device allows to generate and control the spin-polarized current by simple electrical means. [ABSTRACT FROM AUTHOR]

We investigate the electrical switching of charge and spin transport in a topological insulator nanoconstriction in a four-terminal device. The switch of the edge channels is caused by the coupling between edge states which overlap in the constriction and by the tunneling effects at the contacts and therefore can be manipulated by tuning the applied voltages on the split gate or by geometrical etching. The switching mechanism can be conveniently studied by electron interferometry involving the measurements of the current in different configurations of the side gates, while the applied bias from the external leads can be tuned to obtain pure charge or pure spin currents (charge- and spin-bias configurations). Relevant signatures of quantum confinement effects, quantum size effects, and energy gap are evident in the Fabry-Pérot physics of the device, allowing for a full characterization of the charge and spin currents. The proposed electrical switching behavior offers an efficient tool to manipulate topological edge-state transport in a controllable way. [ABSTRACT FROM AUTHOR]

We consider a quantum spin Hall system in a two-terminal setup, with an extended tunneling contact connecting upper and lower edges. We analyze the effects of this geometry on the backscattering current as a function of voltage, temperature, and strength of the electron interactions. We find that this configuration may be useful to confirm the heUcal nature of the edge states and to extract their propagation velocity. By comparing with the usual quantum point-contact geometry, we observe that the power-law behaviors predicted for the backscattering current and the linear conductance are recovered for low enough energies, while different power laws also emerge at higher energies. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To investigate the presence of multiple spinothalamic pathways for warmth in the human spinal cord. Methods: Laser evoked potentials to C-fiber stimulation (C-LEPs) were recorded in 15 healthy subjects after warmth stimulation of the dorsal midline at C5, T2, T6, and T10 vertebral levels. This method allowed us to calculate the spinal conduction velocity (CV) in two different ways: (1) the reciprocal of the slope of the regression line was obtained from the latencies of the different C-LEP components, and (2) the distance between C5 and T10 was divided by the latency difference of the responses at the two sites. In particular, we considered the C-N1 potential, generated in the second somatosensory (SII) area, and the late C-P2 response, generated in the anterior cingulate cortex (ACC). Results: The calculated CV of the spinal fibers generating the C-N1 potential (around 2.5m/s) was significantly different (p <0.01) from the one of the pathway producing the P2 response (around 1.4m/s). Conclusions: Our results suggest that the C-N1 and the C-P2 components are generated by two parallel spinal pathways. Significance: Warmth sensation is subserved by parallel spinothalamic pathways, one probably reaching the SII area, the other the ACC. [Copyright &y& Elsevier]