Synthesis and characterization of attosecond light vortices in the extreme ultraviolet

Infrared and visible light beams carrying orbital angular momentum (OAM) are currently thoroughly studied for their extremely broad applicative prospects, among which are quantum information, micromachining and diagnostic tools. Here we extend these prospects, presenting a comprehensive study for the synthesis and full characterization of optical vortices carrying OAM in the extreme ultraviolet (XUV) domain. We confirm the upconversion rules of a femtosecond infrared helically phased beam into its high-order harmonics, showing that each harmonic order carries the total number of OAM units absorbed in the process up to very high orders (57). This allows us to synthesize and characterize helically shaped XUV trains of attosecond pulses. To demonstrate a typical use of these new XUV light beams, we show our ability to generate and control, through photoionization, attosecond electron beams carrying OAM. These breakthroughs pave the route for the study of a series of fundamental phenomena and the development of new ultrafast diagnosis tools using either photonic or electronic vortices

Bio-electrospraying 3-D Organotypic Human Skin Cultures

Organotypic 3D tissue models have greatly contributed to understand a wide range of molecular and cellular characteristics within a functional or diseased tissue. Human skin reconstructs which act as models are most useful for a wide range of investigations, ranging from tissue engineering and regenerative medicine, drug development, screening, and discovery to name a few. There are many approaches for reconstructing 3D skin tissue models, however, to date there have been very few that are able to generate organotypic 3D constructs with a single technology having minimal processing steps to finally scalability. The many manifestations of 3D bioprinting have contributed to this endeavor, having said that, the technology's limitations have tempered those reconstructed models, as they are known to contain low cell numbers/concentrations to those having damaged/dead molecules/cells within the reconstructed tissue, which are not desirable, for exploring as tissues models. Contrary to 3D bioprinting approaches, bio-electrosprays have been demonstrated to possess the ability to handle large concentrations of cells and molecules to whole fertilized embryos without damaging them from a molecular level upwards. Consequently, this article demonstrates, for the first time, bio-electrospray's capacity to reconstruct skin-like structures in vitro and its potential in reconstructing full-thickness 3D organotypic human skin tissues

A systematic review of economic models used to assess the cost-effectiveness of strategies for identifying latent tuberculosis in high-risk groups

Timely diagnosis and treatment of latent tuberculosis infection (LTBI) through screening remains a key public health priority. Although globally it is recommended to screen people at high risk of developing TB, the economic evidence underpinning these recommendations is limited. This review critically appraised studies that had used a decision-analytical modelling framework to estimate the cost-effectiveness of interferon gamma release assays (IGRAs) compared to tuberculin skin test (TST) for detecting LTBI in high risk populations. A systematic review of economic models used to assess the cost-effectiveness of strategies for identifying latent tuberculosis in high-risk groups (PDF Download Available). Available from: https://www.researchgate.net/publication/301759613_A_systematic_review_of_economic_models_used_to_assess_the_cost-effectiveness_of_strategies_for_identifying_latent_tuberculosis_in_high-risk_groups [accessed May 27, 2016]

Nouvelles Diverses

Transcript of NOUVELLES DIVERSES by Auguste Morel signed A. M., appearing in LE MÉNESTREL, 21 mars 1880, pp. 126-127

First Results of the Phase II SIMPLE Dark Matter Search

We report results of a 14.1 kgd measurement with 15 superheated droplet detectors of total active mass 0.208 kg, comprising the first stage of a 30 kgd Phase II experiment. In combination with the results of the neutron-spin sensitive XENON10 experiment, these results yield a limit of |a_p| < 0.32 for M_W = 50 GeV/c2 on the spin-dependent sector of weakly interacting massive particle-nucleus interactions with a 50% reduction in the previously allowed region of the phase space formerly defined by XENON, KIMS and PICASSO. In the spin-independent sector, a limit of 2.3x10-5 pb at M_W = 45 GeV/c2 is obtained.Comment: 4 pages, 4 figures; PRL-accepted version with corrected SI contour (Fig. 4

Final Analysis and Results of the Phase II SIMPLE Dark Matter Search

We report the final results of the Phase II SIMPLE measurements, comprising two run stages of 15 superheated droplet detectors each, the second stage including an improved neutron shielding. The analyses includes a refined signal analysis, and revised nucleation efficiency based on reanalysis of previously-reported monochromatic neutron irradiations. The combined results yield a contour minimum of \sigma_{p} = 4.2 x 10^-3 pb at 35 GeV/c^2 on the spin-dependent sector of WIMP-proton interactions, the most restrictive to date from a direct search experiment and overlapping for the first time results previously obtained only indirectly. In the spin-independent sector, a minimum of 3.6 x 10^-6 pb at 35 GeV/c^2 is achieved, with the exclusion contour challenging the recent CoGeNT region of current interest.Comment: revised, PRL-accepted version with slightly weakened limit contour

Evaluating PET-CT in the detection and management of recurrent cervical cancer: Systematic reviews of diagnostic accuracy and subjective elicitation

Background: Positron emission tomography-computed tomography (PET-CT) is recommended to triage women for exenterative surgery and surveillance after treatment for advanced cervical cancer. Objective: To evaluate diagnostic accuracy of additional whole body PET-CT compared with CT/magnetic resonance imaging (MRI) alone in women with suspected recurrent/persistent cervical cancer and in asymptomatic women as surveillance. Design: Systematic reviews. Subjective elicitation to supplement diagnostic information. Search strategy/Selection criteria/Data collection and analysis: Searches of electronic databases were performed to June 2013. Studies in women with suspected recurrent/persistent cervical cancer and in asymptomatic women undergoing follow up with sufficient numeric data were included. We calculated sensitivity, specificity and corresponding 95% confidence intervals. Meta-analyses employed a bivariate model that included a random-effects term for between-study variations (CT studies) and univariate random effects meta-analyses (PET-CT studies) for sensitivity and specificity separately. Subjective elicitation: Prevalence of recurrence and the accuracy of imaging elicited using the allocation of points technique. Coherence of elicited subjective probabilities with estimates in the literature examined. Results: We identified 15 relevant studies; none directly compared additional PET-CT with MRI or CT separately. Most CT and MRI studies used older protocols and the majority did not distinguish between asymptomatic and symptomatic women. Meta-analysis of nine PET-CT studies in mostly symptomatic women showed sensitivity of 94.8 (95% CI 91.2-96.9), and specificity of 86.9% (95% CI 82.2-90.5). The summary estimate of the sensitivity of CT for detection of recurrence was 89.64% (95% CI 81.59-94.41) and specificity was 76% (95% CI 43.68-92.82). Meta-analysis for MRI test accuracy studies was not possible because of clinical heterogeneity. The sensitivity and specificity of MRI in pelvic recurrence varied between 82 and 100% and between 78 and 100%, respectively. Formal statistical comparisons of the accuracy of index tests were not possible. Subjective elicitation provided estimates comparable to the literature. Subjective estimates of the increase in accuracy from the addition of PET-CT were less than elicited increases required to justify the use in PET-CT for surveillance. Conclusion: Evidence to support additional PET-CT is scarce, of average quality and does not distinguish between application for surveillance and diagnosis. Guidelines recommending PET-CT in recurrent cervical cancer need to be reconsidered in the light of the existing evidence base

The SIMPLE Phase II Dark Matter Search

Phase II of SIMPLE (Superheated Instrument for Massive ParticLe Experiments) searched for astroparticle dark matter using superheated liquid C$_{2}$ClF$_{5}$ droplet detectors. Each droplet generally requires an energy deposition with linear energy transfer (LET) $\gtrsim$ 150 keV/$\mu$m for a liquid-to-gas phase transition, providing an intrinsic rejection against minimum ionizing particles of order 10$^{-10}$, and reducing the backgrounds to primarily $\alpha$ and neutron-induced recoil events. The droplet phase transition generates a millimetric-sized gas bubble which is recorded by acoustic means. We describe the SIMPLE detectors, their acoustic instrumentation, and the characterizations, signal analysis and data selection which yield a particle-induced, "true nucleation" event detection efficiency of better than 97% at a 95% C.L. The recoil-$\alpha$ event discrimination, determined using detectors first irradiated with neutrons and then doped with alpha emitters, provides a recoil identification of better than 99%; it differs from those of COUPP and PICASSO primarily as a result of their different liquids with lower critical LETs. The science measurements, comprising two shielded arrays of fifteen detectors each and a total exposure of 27.77 kgd, are detailed. Removal of the 1.94 kgd Stage 1 installation period data, which had previously been mistakenly included in the data, reduces the science exposure from 20.18 to 18.24 kgd and provides new contour minima of $\sigma_{p}$ = 4.3 $\times$ 10$^{-3}$ pb at 35 GeV/c$^{2}$ in the spin-dependent sector of WIMP-proton interactions and $\sigma_{N}$ = 3.6 $\times$ 10$^{-6}$ pb at 35 GeV/c$^{2}$ in the spin-independent sector. These results are examined with respect to the fluorine spin and halo parameters used in the previous data analysis.Comment: 20 pages, 19 figures; accepted Physical Review

Elastic and thermal properties of hexagonal perovskites

We systematically investigate the mechanical and thermal properties of the P6₃cm hexagonal perovskites with composition A³+B³+O₃ for potential use in thermal barrier coatings. In spite of the structural anisotropy, the elastic constants are essentially isotropic. The thermal expansion is, however, strongly anisotropic, while the thermal conductivity is relatively isotropic. The thermal conductivities of the hexagonal perovskites are much larger than those of the orthorhombic perovskites

Positron emission tomography/computerised tomography imaging in detecting and managing recurrent cervical cancer: systematic review of evidence, elicitation of subjective probabilities and economic modelling.

© Queen’s Printer and Controller of HMSO 2013. This work was produced by Meads et al. under the terms of a commissioning contract issued by the Secretary of State for Health. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising.Cancer of the uterine cervix is a common cause of mortality in women. After initial treatment women may be symptom free, but the cancer may recur within a few years. It is uncertain whether it is more clinically effective to survey asymptomatic women for signs of recurrence or to await symptoms or signs before using imaging.National Institute for Health Research Health Technology Assessment programm