Energy considerations for a superlens based on metal/dielectric multilayers

We investigate the resolution and absorption losses of a Ag/GaP multilayer superlens. For a fixed source to image distance the resolution is independent of the position of the lens but the losses depend strongly on the lens placement. The absorption losses associated with the evanescent waves can be significantly larger than losses associated with the propagating waves especially when the superlens is close to the source. The interpretation of transmittance values greater than unity for evanescent waves is clarified with respect to the associated absorption losses.Comment: to be published in Optics Expres

Numerical Simulation and Experimental Characterization of Emitter Wrap through Solar Cells with Deep Grooved Base Contact (EWT-DGB)

Abstract In this work we present an Emitter Wrap Through cell with Deep Grooved Base contact (EWT-DGB), designed for both 1-sun and concentrating applications. The proposed approach, which consists in a deep grooved hole array composed by holes of two alternating doping type, allows both a reduction of the cell series resistance and an increase in collection efficiency also by using relatively thick substrates with low lifetime. The measured experimental data including dark J-V characteristics, figures of merit (FOMs) under illumination and external quantum efficiency (EQE) are compared to the results of 3-D drift-diffusion TCAD numerical simulations. Moreover, the impact of the hole spacing and of process-dependent physical parameters (interface defects) on FOMs is investigated by means of simulations

A pilot study employing hepatic intra-arterial irinotecan injection of drug-eluting beads as salvage therapy in liver metastatic colorectal cancer patients without extrahepatic involvement: The first southern Italy experience

Background: The main aim of this prospective study was to evaluate the efficacy of drug-eluting beads with irinotecan (DEBIRI) for liver metastases from colorectal cancer. Secondary aims were to evaluate survival and toxicity. Methods: Twenty-five patients with metastases in <50% of the liver and without extrahepatic involvement were enrolled. Treatment response assessment was performed by multidetector contrast enhancement computed tomography (MDCT) with evaluation of the enhancement pattern of the target lesion and tumor response rates according to modified Response Evaluation Criteria in Solid Tumors (mRECIST, Version 1.1). All adverse events were recorded by the Cancer Therapy Evaluation Program Common Terminology Criteria for Adverse Events, Version 3.0. Associations of tumor response and variables were calculated using the chi-squared test. Overall survival (OS) was calculated using the Kaplan–Meier method. Comparisons were made using the log-rank test. Results: According to mRECIST, complete response (CR) was observed in 21.8% of patients, partial response (PR) in 13%, stable disease (SD) in 52.2% and progressive disease (PD) in 13% of patients. Response rate (RR = CR + PR) was 34.8%. No associations between treatment response and variables such as Dukes’ classification, grading and Kras status were found (P>0.05). The median OS was 37 months (95% CI: 13.881 to 60.119). Cox regression model showed that neither site, Dukes’ classification, grading, Kras status nor number of chemotherapy treatments pre-DEBIRI influenced the OS. The log-rank test showed no statistically significant difference in OS among patients who underwent 1, 2 or 3 DEBIRI treatments (χ2=2.831, P=0.09). In our study, the main toxicities included postembolization syndrome (PES), hypertransaminasemia and fever. Conclusion: The favorable tumor response and the favorable toxicity profile make DEBIRI treatment a potential third-line therapy. Although further larger studies are needed to confirm these data, we can state that DEBIRI is an attractive emerging treatment in these patients

Impairment of T cell development and acute inflammatory response in HIV-1 Tat transgenic mice

Immune activation and chronic inflammation are hallmark features of HIV infection causing T-cell depletion and cellular immune dysfunction in AIDS. Here, we addressed the issue whether HIV-1 Tat could affect T cell development and acute inflammatory response by generating a transgenic mouse expressing Tat in lymphoid tissue. Tat-Tg mice showed thymus atrophy and the maturation block from DN4 to DP thymic subpopulations, resulting in CD4(+) and CD8(+) T cells depletion in peripheral blood. In Tat-positive thymus, we observed the increased p65/NF-κB activity and deregulated expression of cytokines/chemokines and microRNA-181a-1, which are involved in T-lymphopoiesis. Upon LPS intraperitoneal injection, Tat-Tg mice developed an abnormal acute inflammatory response, which was characterized by enhanced lethality and production of inflammatory cytokines. Based on these findings, Tat-Tg mouse could represent an animal model for testing adjunctive therapies of HIV-1-associated inflammation and immune deregulation

MULTI-ROTOR WAKE INTERACTION CHARACTERIZATION

The paper presents part of the experimental activities carried out in the GARTEUR Action Group HC/AG-26 to study the acoustic and aerodynamic characteristics of small rotor configurations, including the influence of the rotor-rotor interactions. Two rotors equipped with two-bladed propellers with a diameter of D=165.1mm were used at two different rotating speeds of 8025 RPM and 10120 RPM and different geometry configurations. Isolated rotor and coaxial configurations in hover conditions were assessed. The rotor slipstream characterization, in terms of aerodynamic loads, flow field velocity and acoustics emissions, was performed using a six-component load cell, Particle Image Velocimetry and microphone array measurements. The effect of the rotor support/fairing on the performance of the isolated rotor was investigated together with the rotorrotor interaction for the coaxial configuration at two rotor distances of Δz = 0.5R and Δz = 1.0 R. The results indicated an effect of the support/fairing on the propeller performance, a loss of thrust of the lower rotor and a higher noise emission for the coaxial configuration characterized by the larger rotor distance. The turbulent kinetic energy and the meandering of the blade tip vortices sustained the acoustics results

Phase-resolved measurements on a multi-slotted Synthetic Jets actuator

The free flow field of a multi-slotted array of Synthetic Jets (SJ) has been experimentally investigated in quiescent ambient at Reynolds and Strouhal numbers, Re = 128 and St = 0.11, respectively. The multi-slotted SJ actuator is composed of twelve rectangular slots with an aspect ratio of 15 (for a width of ~1 mm) and off-centered with respect to the cavity center. Experiments were conducted at three equally-spaced cross sectional planes inspecting two consecutive slots by means of phase-locked Stereo-Particle Image Velocimetry. At the slot exit, the statistical analysis reveals that the SJ exhibits an asymmetric spreading with respect to the geometrical axis of the slot, being tilted of about ~14.8° on the side where the cavity extends. This asymmetric pattern determines a small recirculation region slightly downstream of the slot exit. On the other hand, the flow field appears two-dimensional at the mid spanwise distance between the two slots. The phase-locked flow fields exhibit counter-rotating vortical patterns that convect downstream from the slot exit during the ejection phase. These vortices develop in longitudinal direction at 3.4 slot widths and then dissipate as they travel further downstream

Flow control on a 2D back-facing ramp by Synthetic Jets

Flow control via Synthetic Jets (SJs) is experimentally studied for a separated flow over a back-facing ramp in wind tunnel tests at height-based Reynolds number of 10700 using planar Particle Image Velocimetry. Two cases, i.e., either without control (baseline) or controlled by means of SJs, have been investigated. The effectiveness of the control is achieved through a momentum addition of cμ = 3.0 × 10^(-3) at a reduced frequency F+ = 0.34. Under the SJs control, the separated region undergoes a reduction in length of 62% of that observed for the baseline case

Dynamics of short pulses and phase matched second harmonic generation in negative index materials

We study pulsed second harmonic generation in metamaterials under conditions of significant absorption. Tuning the pump in the negative index range, a second harmonic signal is generated in the positive index region, such that the respective indices of refraction have the same magnitudes but opposite signs. This insures that a forward-propagating pump is exactly phase matched to the backward-propagating second harmonic signal. Using peak intensities of ~500 MW/cm2, assuming χ(2)~80pm/V, we predict conversion efficiencies of 12% and 0.2% for attenuation lengths of 50 and 5μm, respectively

Molecular Analysis of Cluster Headache

Objectives: Cluster headache (CH) is characterized by severe, recurrent, unilateral attacks of extreme intensity and brief duration. Variants in a myriad of genes were studied in sporadic CH patients, often with conflicting results. Methods: We studied gene mutations in some candidate genes, hypocretin receptor 2, Clock, and alcohol dehydrogenase 4 (ADH4), in 54 unrelated sporadic CH patients and in 200 controls in 8 kindreds/families that included more affected and nonaffected cases. Furthermore, we performed the whole-genome scanning by comparative genomic hybridization, searching for rearrangements associated with DNA gain or loss in a subset of sporadic and familial CH and control participants. Results: The analysis of candidate genes revealed that only allele and genotype frequency of the 2 ADH4 mutations resulted significantly between sporadic CH and controls; the same mutations were homozygous in CH patients from 2 families. The comparative genomic hybridization analysis revealed 2 novel rearrangements that involved the intron regions of thyrotropin-releasing hormone-degrading enzyme and neurexin 3 (NRXN3) genes, respectively. The first arrangement was present either in CH or in controls, whereas the second one was specifically found in some sporadic and familial CH cases. Conclusions: Our data (although obtained on a small number of cases) confirm the genetic heterogeneity of CH, suggesting that mutations in the ADH4 gene and a novel rearrangement involving NRXN3 gene might be related to CH in a subset of cases