A study of dye anchoring points in half-squarylium dyes for dye-sensitized solar cells

This paper reports the synthesis of a series of new half-squaraine dyes (Hf-SQ) based around a common chromophoric unit consisting of linked indoline and squaric acid moieties. Carboxylate groups have been incorporated onto this core structure at four different points to study the influence of the anchoring group position on dye-sensitized solar cell (DSC) device performance. Dyes have been linked to TiO2 directly through the squaric acid moiety, through a modified squaric acid unit where a vinyl dicyano group has replaced one carbonyl, via an alkyl carboxylate attached to the indole N or through a carboxylate attached to the 4 position of a benzyl indole. Contact angle measurements have been studied to investigate the hydrophobic/hydrophilic properties of the dyes and the results have been compared to N719 and Z907. Full characterization data of all the dyes and synthetic intermediates are reported including single-crystal X-ray structural analysis for dye precursors; the indole (2a) and the half-squarylium esters (3a) and (6b), as well as the dyes (4c), (8) and (12). Dye colours range from yellow to red/brown in solution (λmax range from 430 to 476 nm) with ε ranging from 38 000 to 133 100 M−1 cm−1. The performance of the dyes in DSCs shows the highest efficiency yet reported for a Hf-SQ dye (η = 5.0%) for 1 cm2 devices with a spectral response ranging from 400 to 700 nm depending on the dye substituents. Co-sensitization of half-squarylium dye (7b) with squaraine dye (SQ2) resulted in a broader spectral response and an improved device efficiency (η = 6.1%). Density functional theory (DFT) calculations and cyclic voltammetry have been used to study the influence of linker position on dye HOMO–LUMO levels and the data has been correlated with I–V and EQE data

Low-field magnetoresistance in GaAs 2D holes

We report low-field magnetotransport data in two-dimensional hole systems in GaAs/AlGaAs heterostructures and quantum wells, in a large density range, $2.5 \times 10^{10} \leq p \leq 4.0 \times 10^{11}$ cm$^{-2}$, with primary focus on samples grown on (311)A GaAs substrates. At high densities, $p \gtrsim 1 \times 10^{11}$ cm$^{-2}$, we observe a remarkably strong positive magnetoresistance. It appears in samples with an anisotropic in-plane mobility and predominantly along the low-mobility direction, and is strongly dependent on the perpendicular electric field and the resulting spin-orbit interaction induced spin-subband population difference. A careful examination of the data reveals that the magnetoresistance must result from a combination of factors including the presence of two spin-subbands, a corrugated quantum well interface which leads to the mobility anisotropy, and possibly weak anti-localization. None of these factors can alone account for the observed positive magnetoresistance. We also present the evolution of the data with density: the magnitude of the positive magnetoresistance decreases with decreasing density until, at the lowest density studied ($p = 2.5 \times 10^{10}$ cm$^{-2}$), it vanishes and is replaced by a weak negative magnetoresistance.Comment: 8 pages, 8 figure

SUPEROVULAÇÃO OVARIANA E PRODUÇÃO DE EMBRIÕES EM Bubalus bubalis

The aim of the present research work was to optimize ovarian superovulation rate and the embryo production in Murrah and Mediterranean buffaloes around the 60th day after parturition. Fourteen animals were divided in two groups of 7 animals each, G1 (treated animals) and G2 (untreated animals). All animals were subjected to a step of oestrus synchronization by receiving at the 0 day (OD) a vaginal pressary with progestagen (CIDR-B, Intervet), followed by the administration, in the morning of the day 1 (D1), of 3 mg stradiol benzoate IM (Estrogin, Farmavet, SP). The ovarian superovulation (SO) was carried out daily, at intervals of 12 hours in the morning and the afternoon by means of the administration of follicule stimulant hormone (FSH) (Pluset, Serono, Italy) in both groups of experimental animals, during four days according to the following protocol: at the 6th day, 75 IU; at the 7th day, 40 IU; at the 8th day, 30 IU; and at the 9th day, 20 IU. At the afternoon of the 8th day, administration of 500 µg of cloprostenol IM (Closin-Schering-Plough) was performed followed by the withdraw of the vaginal pessaries from all animals. Then, observations on the estrus of the experimental animals has been carried out. For this purpose the animals were inseminated twice at intervals of 12 hours. Additionaly, all animals from the G1, together with the first artificial insemination (AI) received a dose of 3000 UI of gonadotrophic chorionic hormone (GCH) (Vetecor, Calier, IV) while the G2 animals received 1 ml of saline as placebo. All animals from both G1 and G2 groups had their ovaries monitored by ultrasonography from the first day of the AI up to the day when they had their embryos collected. Ultrasography has been carried out by means of an Aloka SSD-550 (Japan) instrument aiming to evaluate the follicles, the ovulation, and the corpora lutea. At the 5.5th after the estrus observation a washing of the uterine cornus has been carried out for the embryos harvesting and evaluation. According to the present experiment, it was possible to conclude that the protocol used to promote superovulation (SO) in buffaloes by means of FSH showed to be efficient resulting in the production of significant number of antral follicles larger than 8.0 mm diameter at the estrus day and that the gonadotropohic corionic hormone showed significant efficiency by displaying larger percentual ovulations in the treated group (pO presente estudo objetivou otimizar a superovulação ovariana, a taxa de ovulação e a produção de embriões em búfalas. Os animais eram da raça Murrah e Mediterrâneo e estavam em torno do 60º dia pós parto. Quatorze animais foram divididos em dois grupos, sendo um grupo tratado (G1=7 animais) e outro não-tratado (G2=7 animais). Todos os animais foram submetidos à sincronização do estro, recebendo no dia 0 (D0) um pessário vaginal com progestágeno (CIDR-B, Intervet); no dia 1 (D1) pela manhã foi aplicado 3 mg de benzoato de estradiol IM (Estrogin Farmavet, SP). A superovulação ovariana (SO) foi executada pela manhã e à tarde com hormônio folículo estimulante (FSH)(Pluset, Serono, Itália)), administrado diariamente a intervalo de 12 horas entre cada aplicação, durante quatro dias seguidos nos dois grupos, conforme o protocolo: dia 6, 75 UI; dia 7, 40 UI; dia 8, 30 UI; dia 9, 20 UI. No dia 8 à tarde administrou-se 500 microgramas de cloprostenol IM (Ciosin - Schering-Plough) e em seguida houve a retirada dos pessários vaginais de todos os animais. Na sequência, foram feitas as observações de cio; os animais foram inseminados duas vezes a intervalos de 12 horas um do outro. Adicionalmente, o G1 recebeu junto com a 1ª inseminação artificial (IA), uma dose de 3000 UI de hormônio coriônico gonadotrófico (hCG) (Vetecor, Calier, IV) e o G2 recebeu 1 ml de solução fisiológica, como placebo. Todos os animais tiveram os ovários monitorados mediante ultrassonografia, desde o dia da 1ª IA até o dia da coleta dos embriões, mediante aparelho Aloka SSD-550 (Japão), visando a avaliação de folículos, ovulação e corpos lúteos. No 5,5º dia pós a observação de cio, procedeu-se às lavagens dos cornos uterinos para a colheita dos embriões e avaliação. Concluiu-se que o protocolo utilizado para SO em bubalinos com FSH, foi eficiente, ao promover significativo numero de folículos antrais maiores que 8,0 mm de diâmetro no dia do cio e que o hCG mostrou-se significativamente eficiente, pois proporcionou maior % de ovulações no grupo tratado (

Output spectrum of a detector measuring quantum oscillations

We consider a two-level quantum system (qubit) which is continuously measured by a detector and calculate the spectral density of the detector output. In the weakly coupled case the spectrum exhibits a moderate peak at the frequency of quantum oscillations and a Lorentzian-shape increase of the detector noise at low frequency. With increasing coupling the spectrum transforms into a single Lorentzian corresponding to random jumps between two states. We prove that the Bayesian formalism for the selective evolution of the density matrix gives the same spectrum as the conventional master equation approach, despite the significant difference in interpretation. The effects of the detector nonideality and the finite-temperature environment are also discussed.Comment: 8 pages, 6 figure

High Magnetic Field Microwave Conductivity of 2D Electrons in an Array of Antidots

We measure the high magnetic field ($B$) microwave conductivity, Re$\sigma_{xx}$, of a high mobility 2D electron system containing an antidot array. Re$\sigma_{xx}$ vs frequency ($f$) increases strongly in the regime of the fractional quantum Hall effect series, with Landau filling $1/3<\nu<2/3$. At microwave $f$, Re$\sigma_{xx}$ vs $B$ exhibits a broad peak centered around $\nu=1/2$. On the peak, the 10 GHz Re$\sigma_{xx}$ can exceed its dc-limit value by a factor of 5. This enhanced microwave conductivity is unobservable for temperature $T \gtrsim 0.5$ K, and grows more pronounced as $T$ is decreased. The effect may be due to excitations supported by the antidot edges, but different from the well-known edge magnetoplasmons.Comment: 4 pages, 3 figures, revtex

Convergence calls: multimedia storytelling at British news websites

This article uses qualitative interviews with senior editors and managers from a selection of the UK's national online news providers to describe and analyse their current experimentation with multimedia and video storytelling. The results show that, in a period of declining newspaper readership and TV news viewing, editors are keen to embrace new technologies, which are seen as being part of the future of news. At the same time, text is still reported to be the cornerstone for news websites, leading to changes in the grammar and function of news video when used online. The economic rationale for convergence is examined and the article investigates the partnerships sites have entered into in order to be able to serve their audience with video content. In-house video is complementing syndicated content, and the authors examine the resulting developments in newsroom training and recruitment practices. The article provides journalism and interactive media scholars with case studies on the changes taking place in newsrooms as a result of the shift towards multimedia, multiplatform news consumption

Templates for Convex Cone Problems with Applications to Sparse Signal Recovery

This paper develops a general framework for solving a variety of convex cone problems that frequently arise in signal processing, machine learning, statistics, and other fields. The approach works as follows: first, determine a conic formulation of the problem; second, determine its dual; third, apply smoothing; and fourth, solve using an optimal first-order method. A merit of this approach is its flexibility: for example, all compressed sensing problems can be solved via this approach. These include models with objective functionals such as the total-variation norm, ||Wx||_1 where W is arbitrary, or a combination thereof. In addition, the paper also introduces a number of technical contributions such as a novel continuation scheme, a novel approach for controlling the step size, and some new results showing that the smooth and unsmoothed problems are sometimes formally equivalent. Combined with our framework, these lead to novel, stable and computationally efficient algorithms. For instance, our general implementation is competitive with state-of-the-art methods for solving intensively studied problems such as the LASSO. Further, numerical experiments show that one can solve the Dantzig selector problem, for which no efficient large-scale solvers exist, in a few hundred iterations. Finally, the paper is accompanied with a software release. This software is not a single, monolithic solver; rather, it is a suite of programs and routines designed to serve as building blocks for constructing complete algorithms.Comment: The TFOCS software is available at http://tfocs.stanford.edu This version has updated reference

Randomized phase III trial of consolidation therapy with bortezomib–lenalidomide–Dexamethasone (VRd) vs bortezomib–dexamethasone (Vd) for patients with multiple myeloma who have completed a dexamethasone based induction regimen

Long-awaited results from the the Southwest Oncology Group (SWOG) trial comparing bortezomib–lenalidomide-dexamethasone (VRd) versus lenalidomide-dexamethasone (Rd) as induction treatment for previously untreated multiple myeloma (MM) patients were recently presented (S0777).1 Results justified the early adoption of VRd in the frontline setting over 5 years ago by the NCCN based on Level 2A evidence according to their guidelines.2 The randomized study E1A05 also sought to evaluate VRd superiority over a doublet (Vd), but in the consolidation setting. The trial was closed to enrollment prematurely due to slow accrual. Results reported here include 48 enrolled patients.This study was coordinated by the ECOG-ACRIN Cancer Research Group (Robert L Comis, MD, and Mitchell D Schnall, MD, PhD, Group Co-Chairs) and supported by the National Cancer Institute of the National Institutes of Health under award numbers: CA180820, CA180794, CA21115, CA23318, CA66636, CA180790, CA13650, CA189956, CA35412, CA15488, CA180799 and CA21076.http://www.sherpa.ac.uk/romeo/issn/2044-5385/am2016Medical Oncolog

Stellar evolution and modelling stars

In this chapter I give an overall description of the structure and evolution of stars of different masses, and review the main ingredients included in state-of-the-art calculations aiming at reproducing observational features. I give particular emphasis to processes where large uncertainties still exist as they have strong impact on stellar properties derived from large compilations of tracks and isochrones, and are therefore of fundamental importance in many fields of astrophysics.Comment: Lecture presented at the IVth Azores International Advanced School in Space Sciences on "Asteroseismology and Exoplanets: Listening to the Stars and Searching for New Worlds" (arXiv:1709.00645), which took place in Horta, Azores Islands, Portugal in July 201

Ultra-red Galaxies Signpost Candidate Protoclusters at High Redshift

We present images obtained with LABOCA of a sample of 22 galaxies selected via their red Herschel SPIRE colors. We aim to see if these luminous, rare, and distant galaxies are signposting dense regions in the early universe. Our 870 μm survey covers an area of ≈1 deg2 down to an average rms of $3.9\,\mathrm{mJy}\,{\mathrm{beam}}^{-1}$, with our five deepest maps going ≈2× deeper still. We catalog 86 dusty star-forming galaxies (DSFGs) around our "signposts," detected above a significance of 3.5σ. This implies a ${100}_{-30}^{+30} \%$ overdensity of ${S}_{870}\gt 8.5\,\mathrm{mJy}$ (or {L}_{\mathrm{FIR}}=6.7\times {10}^{12}\mbox{--}2.9\times {10}^{13}\,{L}_{\odot }) DSFGs, excluding our signposts, when comparing our number counts to those in "blank fields." Thus, we are 99.93% confident that our signposts are pinpointing overdense regions in the universe, and ≈95% [50%] confident that these regions are overdense by a factor of at least ≥1.5 × [2×]. Using template spectral energy distributions (SEDs) and SPIRE/LABOCA photometry, we derive a median photometric redshift of z = 3.2 ± 0.2 for our signposts, with an inter-quartile range of z = 2.8–3.6, somewhat higher than expected for ~850 μm selected galaxies. We constrain the DSFGs that are likely responsible for this overdensity to within $| {\rm{\Delta }}z| \leqslant 0.65$ of their respective signposts. These "associated" DSFGs are radially distributed within (physical) distances of 1.6 ± 0.5 Mpc from their signposts, have median star formation rates (SFRs) of $\approx (1.0\pm 0.2)\times {10}^{3}\,{M}_{\odot }\,{\mathrm{yr}}^{-1}$ (for a Salpeter stellar inital mass function) and median gas reservoirs of $\sim 1.7\times {10}^{11}\,{M}_{\odot }$. These candidate protoclusters have average total SFRs of at least $\approx (2.3\pm 0.5)\times {10}^{3}\,{M}_{\odot }\,{\mathrm{yr}}^{-1}$ and space densities of ~9 × 10−7 Mpc−3, consistent with the idea that their constituents may evolve to become massive early-type galaxies in the centers of the rich galaxy clusters we see today