Faithful entanglement swapping based on sum-frequency generation

We show that the entanglement resulting from an entanglement swapping operation performed with spontaneous parametric down-conversion can be made faithful without post-selection using sum-frequency generation. This invites us to revisit the sum-frequency process and from a proof-of-principle experiment, we demonstrate that it provides a realistic solution for non-linear optics at the single-photon level. This opens the way to attractive alternatives to six-photon protocols based on linear optics used e.g. for the heralded creation of maximally entangled pairs or for the implementation of device-independent quantum key distribution.Comment: 5 pages, 4 figure

Silicon accumulation in maize negatively impacts the feeding and life history traits of Spodoptera exigua Hübner

Silicon (Si) accumulation in plant tissues helps alleviate abiotic and biotic stresses, including infestation by insect pests. Here, we tested the hypothesis that Si concentration in maize leaves negatively impacts Spodoptera exigua Hübner (Lepidoptera: Noctuidae) with respect to: (i) feeding preferences; (ii) leaf digestion; and (iii) life history traits. We produced three groups of maize plants cultivated in a hydroponic system that had contrasting Si concentrations in their tissues (i.e., 0.21 ± 0.03, 4.45 ± 0.50 and 8.46 ± 0.61 g Si Kg-1 DW). In choice assays, fifth instars preferentially consumed leaves containing lower Si concentrations. In no choice-assays, we found that the approximate digestibility (AD) of larvae feeding on Si-enriched leaves was not affected. However, these larvae exhibited a 32% reduction in relative growth rates. Higher Si concentration in maize leaves extended larval development by three days; from 18.07 ± 0.29 when feeding on Si- diet to 21.39 ± 0.21 days on the Si++ enriched diet. Silicon also reduced larval survival by 18% and pupal weight by 20%. Our results confirm that Si supplementation in soil enhances the ability of plants to resist infestation with chewing insects, and should be considered as a viable option in the existing range of sustainable management practices

Decoration of carbon nanotubes by semiconducting or metallic nanoparticles using fluidized bed chemical vapour deposition

Multi-Walled Carbon Nanotubes (MWCNTs) have promising properties that make them potentially useful in a wide variety of applications. The decoration of MWCNTs by metallic or semiconducting nanoparticles aims to intensify some of their properties, in particular thermal and electrical conductivity. Fluidized Bed Chemical Vapour Deposition (FBCVD) is an efficient process to uniformly coat powders by various materials. The coating by SnO2, Fe and Si nanoparticles of MWCNTs (Graphistrength®) tangled in balls of 360 microns in mean diameter using the FBCVD process has been studied. The influence of some deposition parameters with and without oxidative pre-treatment is analysed on the nucleation and growth of nanoparticles. The various results obtained indicate that the intrinsic surface reactivity of MWCNTs is high enough for CVD precursors involving the formation of highly reactive unsaturated species such as silylene SiH2 formed from silane SiH4 pyrolysis in the case of Si deposition. But it must be enhanced for less reactive CVD precursors such as tin tetrachloride SnCl4 which needs the presence of oxygen-containing groups at the nanotube surface to allow Sn nucleation. So, provided the reactivity of the powder surface and that of the CVD precursors are well tuned, the FBCVD process can uniformly coat the outer surface of MWCNTs by metallic or semiconducting nanoparticles

Coherent frequency-down-conversion interface for quantum repeaters

We report a coherence-preserving photon frequency down-conversion experiment based on difference-frequency generation in a periodically poled Lithium niobate waveguide, at the single-photon level. The coherence of the process has been demonstrated by measuring the phase coherence of pseudo single-photon time-bin qubits after frequency conversion with an interference visibility of > 96 %. This interface could be of interest for quantum repeater based hybrid networks.Comment: 6 pages, 3 figure

Natural history and mid-term prognosis of severe tricuspid regurgitation: A cohort study.

OBJECTIVES The objective of this study was to characterize a population of patients with severe tricuspid regurgitation (TR) evaluated at a tertiary care center, assess mid-term clinical outcomes, and identify prognostic factors. BACKGROUND The impact of TR on morbidity and mortality is increasingly recognized. Clinical characteristics and long-term outcomes of patients suffering from TR remain unclear. METHODS This is a retrospective observational single-center study from a tertiary care hospital including patients with echocardiographic diagnosis of severe TR between January 2017 and December 2018. We used the Kaplan-Meier method to estimate survival for up to 4 years. After excluding patients with tricuspid valve (TV) intervention and surgery during follow-up, a multivariate analysis was performed to assess predictors of 2-year mortality using the Cox regression model. RESULTS A total of 278 patients (mean age 74.9 ± 13.7 years, 47.8% female) with severe TR were included in the study. The majority (83.1%; n = 231) had secondary TR. Comorbidities such as atrial fibrillation (AFib) (68.0%; n = 189), severe renal failure (44.2%; n = 123), pulmonary hypertension (PHT) (80.9%; n = 225), and right ventricular (RV) dysfunction (59.7%; n = 166) were highly prevalent. More than half of patients with a cardiac implantable electronic device (CIED) (54.3%; n = 44) showed echocardiographic signs of lead-leaflet interaction causing or contributing to TR. The estimated 2- and 4-year all-cause mortality was 50 and 69%, respectively. Using multivariate analysis, age, severe renal failure, heart failure with reduced ejection fraction (HFrEF), and vena contracta width ≥14 mm were identified as predictors of 2-year mortality. Nine percent (n = 25) of the study cohort underwent transcatheter or surgical treatment for TR during follow-up. CONCLUSION Our study shows the high burden of morbidity and the dismal survival of patients with severe TR. It also highlights the extent of the therapeutic need, since the vast majority of patients were left untreated. Additionally, CIED RV lead-associated TR was prevalent suggesting a need for more attention in clinical routine and research

Crystallization-induced gelling as a method to 4D print low-water-content non-isocyanate polyurethane hydrogels

The use of three-dimensional (3D) printable hydrogels for biomedical applications has attracted considerable attention as a consequence of the ability to precisely define the morphology of the printed object, allowing patients’ needs to be targeted. However, the majority of hydrogels do not possess suitable mechanical properties to fulfill an adequate rheological profile for printability, and hence, 3D printing of cross-linked networks is challenging and normally requires postprinting modifications to obtain the desired scaffolds. In this work, we took advantage of the crystallization process of poly(ethylene glycol) to print non-isocyanate poly(hydroxyurethane) hydrogels with tunable mechanical properties. As a consequence of the crystallization process, the hydrogel modulus can be tuned up to 3 orders of magnitude upon heating up to 40 °C, offering an interesting strategy to directly 3D-print hydrogels without the need of postprinting cross-linking. Moreover, the absence of any toxicity makes these materials ideal candidates for biomedical applications

PerM: efficient mapping of short sequencing reads with periodic full sensitive spaced seeds

Motivation: The explosion of next-generation sequencing data has spawned the design of new algorithms and software tools to provide efficient mapping for different read lengths and sequencing technologies. In particular, ABI's sequencer (SOLiD system) poses a big computational challenge with its capacity to produce very large amounts of data, and its unique strategy of encoding sequence data into color signals