Optical guided dispersions and subwavelength transmissions in dispersive plasmonic circular holes

The light transmission through a dispersive plasmonic circular hole is numerically investigated with an emphasis on its subwavelength guidance. For a better understanding of the effect of the hole diameter on the guided dispersion characteristics, the guided modes, including both the surface plasmon polariton mode and the circular waveguide mode, are studied for several hole diameters, especially when the metal cladding has a plasmonic frequency dependency. A brief comparison is also made with the guided dispersion characteristics of a dispersive plasmonic gap [K. Y. Kim, et al., Opt. Express 14, 320-330 (2006)], which is a planar version of the present structure, and a circular waveguide with perfect electric conductor cladding. Finally, the modal behavior of the first three TM-like principal modes with varied hole diameters is examined for the same operating mode.Comment: 20 pages, 5 figures, 1 tabl

Enhancement of electron energy to the multi-gev regime by a dual-stage laser-wakefield accelerator pumped by petawatt laser pulses

Laser-wakefield acceleration offers the promise of a compact electron accelerator for generating a multi-GeV electron beam using the huge field gradient induced by an intense laser pulse, compared to conventional rf accelerators. However, the energy and quality of the electron beam from the laser-wakefield accelerator have been limited by the power of the driving laser pulses and interaction properties in the target medium. Recent progress in laser technology has resulted in the realization of a petawatt (PW) femtosecond laser, which offers new capabilities for research on laser-wakefield acceleration. Here, we present a significant increase in laser-driven electron energy to the multi-GeV level by utilizing a 30-fs, 1-PW laser system. In particular, a dual-stage laser-wakefield acceleration scheme (injector and accelerator scheme) was applied to boost electron energies to over 3 GeV with a single PW laser pulse. Three-dimensional particle-in-cell simulations corroborate the multi-GeV electron generation from the dual-stage laser-wakefield accelerator driven by PW laser pulses. © 2013 American Physical Society.11852091sciescopu

Xenopus: An alternative model system for identifying muco-active agents

The airway epithelium in human plays a central role as the first line of defense against environmental contaminants. Most respiratory diseases such as chronic obstructive pulmonary disease (COPD), asthma, and respiratory infections, disturb normal muco-ciliary functions by stimulating the hypersecretion of mucus. Several muco-active agents have been used to treat hypersecretion symptoms in patients. Current muco-active reagents control mucus secretion by modulating either airway inflammation, cholinergic parasympathetic nerve activities or by reducing the viscosity by cleaving crosslinking in mucin and digesting DNAs in mucus. However, none of the current medication regulates mucus secretion by directly targeting airway goblet cells. The major hurdle for screening potential muco-active agents that directly affect the goblet cells, is the unavailability of in vivo model systems suitable for high-throughput screening. In this study, we developed a high-throughput in vivo model system for identifying muco-active reagents using Xenopus laevis embryos. We tested mucus secretion under various conditions and developed a screening strategy to identify potential muco-regulators. Using this novel screening technique, we identified narasin as a potential muco-regulator. Narasin treatment of developing Xenopus embryos significantly reduced mucus secretion. Furthermore, the human lung epithelial cell line, Calu-3, responded similarly to narasin treatment, validating our technique for discovering muco-active reagents. © 2018 Sim et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited © 2018 Sim et al

Resistive switching of iron oxide nanoparticles in patterned array structure on flexible substrate

Resistive switching characteristics of maghemite (??-Fe 2O3) nanoparticle (NP) assembly were investigated in patterned array structure of Pt/??-Fe2O3/Pt on a flexible polyethylene terephthalate (PET) substrate. The NPs layer was formed through dip-coating process. The cross-bar array patterned devices with NPs sandwiched between Pt electrodes exhibited memristive switching with hysteresis in current-voltage characteristics with gradually changing resistance with respect to the bias conditions. ?? The Electrochemical Society

High efficiency perovskite light-emitting diodes of ligand-engineered colloidal formamidinium lead bromide nanoparticles

Formamidinium (FA, CH(NH2)2) lead bromide perovskite (FAPbBr3) nanoparticles (NPs) are promising emitters due to their high stability and ability to emit pure green color in both film and solution states. Even though various types of metal halide NP emitters in solution have shown high photoluminescence quantum efficiencies (PLQEs), electroluminescence efficiencies of the light-emitting diodes (LEDs) using the NP films are still much poorer, possibly due to the insulating ligands which can impede the charge injection and transport in films. Therefore, the organic ligand of NPs should be designed to facilitate charge injection and transport in LEDs. Here, we synthesize ligand-engineered colloidal FAPbBr3 NPs at RT and demonstrate high efficiency perovskite NP LEDs based on the FAPbBr3 NPs. Control of ligand length reduces trap-assisted recombination of carriers at the surface traps, and thus maximizes the PLQE of FAPbBr3 NPs. Ligand engineering can also improve the charge injection and transport capability in FAPbBr3 NP films. With this ligand engineering method, we achieve maximum current efficiency of 9.16?cd/A in LEDs based on FAPbBr3 NPs, which is the highest efficiency in FAPbBr3 NP-LEDs to date. The ligand engineering method reported here can be a simple way to improve the luminescence efficiency of optoelectronic devices based on perovskite NP LEDs. ? 2017 Elsevier Ltd1148sciescopu

Association of Bevacizumab Plus Oxaliplatin-Based Chemotherapy With Disease-Free Survival and Overall Survival in Patients With Stage II Colon Cancer A Secondary Analysis of the AVANT Trial

Quimioteràpia; Supervivència sense malaltia; Càncer de còlonQuimioterapia; Supervivencia sin enfermedad; Cáncer de colonChemotherapy; Disease-Free Survival; Colon CancerImportance In the pivotal Multicenter Study of Oxaliplatin/5FU-LV in the Adjuvant Treatment of Colon Cancer (MOSAIC) trial, patients with high-risk stage II colon cancer (CC) had 5-year and 10-year overall survival (OS) rates of 88% and 75%, respectively, with adjuvant fluorouracil and oxaliplatin–based chemotherapy; the Bevacizumab-Avastin Adjuvant (AVANT) trial did not demonstrate a disease-free survival (DFS) benefit of adding bevacizumab to oxaliplatin-based chemotherapy in stage III CC and suggested a detrimental effect on OS. The Long-term Survival AVANT (S-AVANT) study was designed to collect extended follow-up for patients in the AVANT trial. Objective To explore the efficacy of adjuvant bevacizumab combined with oxaliplatin-based chemotherapy in patients with high-risk, stage II CC. Design, Setting, and Participants This prespecified secondary end point analysis of the AVANT and S-AVANT studies included 573 patients with curatively resected high-risk stage II CC and at least 1 of the following criteria: stage T4, bowel obstruction or perforation, blood and/or lymphatic vascular invasion and/or perineural invasion, age younger than 50 years, or fewer than 12 nodes analyzed. The AVANT study was a multicenter randomized stage 3 clinical trial. Data were collected from December 2004 to February 2019, and data for this study were analyzed from March to September 2019. Intervention Patients were randomly assigned to receive 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX4), FOLFOX4 with bevacizumab, or capecitabine and oxaliplatin (XELOX) with bevacizumab. Main Outcomes and Measures The primary end points of this secondary analysis were DFS and OS in patients with high-risk stage II CC. Results The AVANT study included 3451 patients, of whom 573 (16.6%) had high-risk stage II CC (192 [33.5%] randomized to FOLFOX4 group; 194 [33.9%] randomized to FOLFOX4 with bevacizumab group; 187 [32.6%] randomized to XELOX with bevacizumab group). With a median (interquartile range) age of 57.0 (47.2-65.7) years, the study population comprised 325 men (56.7%) and 248 women (43.3%). After a median (interquartile range) follow-up of 6.9 (6.1-11.3) years, the 3-year DFS and 5-year OS rates were 88.2% (95% CI, 83.7%-93.0%) and 89.7% (95% CI, 85.4%-94.2%) in the FOLFOX4 group, 86.6% (95% CI, 81.8%-91.6%) and 89.7% (95% CI, 85.4%-94.2%) in the FOLFOX4 with bevacizumab group, and 86.7% (95% CI, 81.8%-91.8%) and 93.2% (95% CI, 89.6%-97.0%) in the XELOX with bevacizumab group, respectively. The DFS hazard ratio was 0.94 (95% CI, 0.59-1.48; P = .78) for FOLFOX4 with bevacizumab vs FOLFOX4 and 1.07 (95% CI, 0.69-1.67; P = .76) for XELOX with bevacizumab vs FOLFOX4. The OS hazard ratio was 0.92 (95% CI, 0.55-1.55; P = .76) for FOLFOX4 with bevacizumab vs FOLFOX4 and 0.85 (95% CI, 0.50-1.44; P = .55) for XELOX with bevacizumab vs FOLFOX4. Conclusions and Relevance In this secondary analysis of data from the AVANT trial, adding bevacizumab to oxaliplatin-based chemotherapy was not associated with longer DFS or OS in patients with high-risk stage II CC. The findings suggest that the definition of high-risk stage II CC needs to be revisited.This study was funded by Roche

An MMC-based cryogenic calorimeter with a massive sodium molybdate crystal absorber for neutrinoless double beta decay searches

Sodium molybdate crystals are excellent scintillating target material that can be used to investigate the neutrinoless double beta decay of 100Mo. Because this material contains Na nuclei, it could also be used to clarify the contribution of Na in the controversial claim of dark matter observation by the DAMA/LIBRA experiment. Recent developments have allowed the growth of sodium molybdate crystals of several hundred grams, which makes it possible to build large scale experiments. Therefore, a cryogenic calorimeter with a crystal of significant mass, which can exploit the excellent energy resolution from thermal signals and particle identification using the scintillation signals, is highly desired. We have developed a cryogenic calorimeter with a cylindrical sodium molybdate crystal of 178 g with dimensions of 4 cm (height) × 4 cm (diameter) coupled to a metallic magnetic calorimeter (MMC). The detector was also equipped with a light detector with a thin Ge absorber to detect scintillation signals. The detector test measurements showed excellent energy resolution and particle discrimination using dual detection of heat and light signals, and thus demonstrate that the crystal is a promising tool for searching for rare phenomena events. Details of the detector development with the massive sodium molybdate crystal are discussed in this paper along with the performance results from test measurements.11Nsciescopu