Oral immunization of haemaggulutinin H5 expressed in plant endoplasmic reticulum with adjuvant saponin protects mice against highly pathogenic avian influenza A virus infection

Pandemics in poultry caused by the highly pathogenic avian influenza (HPAI) A virus occur too frequently globally, and there is growing concern about the HPAI A virus due to the possibility of a pandemic among humans. Thus, it is important to develop a vaccine against HPAI suitable for both humans and animals. Various approaches are underway to develop such vaccines. In particular, an edible vaccine would be a convenient way to vaccinate poultry because of the behaviour of the animals. However, an edible vaccine is still not available. In this study, we developed a strategy of effective vaccination of mice by the oral administration of transgenic Arabidopsis plants (HA-TG) expressing haemagglutinin (HA) in the endoplasmic reticulum (ER). Expression of HA in the ER resulted in its high-level accumulation, N-glycosylation, protection from proteolytic degradation and long-term stability. Oral administration of HA-TG with saponin elicited high levels of HA-specific systemic IgG and mucosal IgA responses in mice, which resulted in protection against a lethal influenza virus infection with attenuated inflammatory symptoms. Based on these results, we propose that oral administration of freeze-dried leaf powders from transgenic plants expressing HA in the ER together with saponin is an attractive strategy for vaccination against influenza A virus.X111411Ysciescopu

Neural networks for cryptocurrency evaluation and price fluctuation forecasting

International audienceToday, there is a growing number of digital assets, often built on questionable technical foundations. We design and implement supervized learning models in order to explore different aspects of a cryptocurrency affecting its performance, its stability as well as its daily price fluctuation. One characteristic feature of our approach is that we aim at a holistic view that would integrate all available information: First, financial information, including market capitalization and historical daily prices. Second, features related to the underlying blockchain from blockchain explorers like network activity: blockchains handle the supply and demand of a cryptocurrency. Lastly, we integrate software development metrics based on GitHub activity by the supporting team. We set two goals. First, to classify a given cryptocurrency by its performance, where stability and price increase are the positive features. Second, to forecast daily price tendency through regression; this is of course a well-studied problem. A related third goal is to determine the most relevant features for such analysis. We compare various neural networks using most of the widely traded digital currencies (e.g. Bitcoin, Ethereum and Litecoin) in both classification and regression settings. Simple Feedforward neural networks are considered, as well as Recurrent neural networks (RNN) along with their improvements, namely Long Short-Term Memory and Gated Recurrent Units. The results of our comparative analysis indicate that RNNs provide the most promising results

Ripple Texturing of Suspended Graphene Atomic Membranes

Graphene is the nature's thinnest elastic membrane, with exceptional mechanical and electrical properties. We report the direct observation and creation of one-dimensional (1D) and 2D periodic ripples in suspended graphene sheets, using spontaneously and thermally induced longitudinal strains on patterned substrates, with control over their orientations and wavelengths. We also provide the first measurement of graphene's thermal expansion coefficient, which is anomalously large and negative, ~ -7x10^-6 K^-1 at 300K. Our work enables novel strain-based engineering of graphene devices.Comment: 15 pages, 4 figure

Thermal Properties of Carbon Nanotube–Copper Composites for Thermal Management Applications

Carbon nanotube–copper (CNT/Cu) composites have been successfully synthesized by means of a novel particles-compositing process followed by spark plasma sintering (SPS) technique. The thermal conductivity of the composites was measured by a laser flash technique and theoretical analyzed using an effective medium approach. The experimental results showed that the thermal conductivity unusually decreased after the incorporation of CNTs. Theoretical analyses revealed that the interfacial thermal resistance between the CNTs and the Cu matrix plays a crucial role in determining the thermal conductivity of bulk composites, and only small interfacial thermal resistance can induce a significant degradation in thermal conductivity for CNT/Cu composites. The influence of sintering condition on the thermal conductivity depended on the combined effects of multiple factors, i.e. porosity, CNTs distribution and CNT kinks or twists. The composites sintered at 600°C for 5 min under 50 MPa showed the maximum thermal conductivity. CNT/Cu composites are considered to be a promising material for thermal management applications

Application of Graphene within Optoelectronic Devices and Transistors

Scientists are always yearning for new and exciting ways to unlock graphene's true potential. However, recent reports suggest this two-dimensional material may harbor some unique properties, making it a viable candidate for use in optoelectronic and semiconducting devices. Whereas on one hand, graphene is highly transparent due to its atomic thickness, the material does exhibit a strong interaction with photons. This has clear advantages over existing materials used in photonic devices such as Indium-based compounds. Moreover, the material can be used to 'trap' light and alter the incident wavelength, forming the basis of the plasmonic devices. We also highlight upon graphene's nonlinear optical response to an applied electric field, and the phenomenon of saturable absorption. Within the context of logical devices, graphene has no discernible band-gap. Therefore, generating one will be of utmost importance. Amongst many others, some existing methods to open this band-gap include chemical doping, deformation of the honeycomb structure, or the use of carbon nanotubes (CNTs). We shall also discuss various designs of transistors, including those which incorporate CNTs, and others which exploit the idea of quantum tunneling. A key advantage of the CNT transistor is that ballistic transport occurs throughout the CNT channel, with short channel effects being minimized. We shall also discuss recent developments of the graphene tunneling transistor, with emphasis being placed upon its operational mechanism. Finally, we provide perspective for incorporating graphene within high frequency devices, which do not require a pre-defined band-gap.Comment: Due to be published in "Current Topics in Applied Spectroscopy and the Science of Nanomaterials" - Springer (Fall 2014). (17 pages, 19 figures

Thermal Properties of Graphene, Carbon Nanotubes and Nanostructured Carbon Materials

Recent years witnessed a rapid growth of interest of scientific and engineering communities to thermal properties of materials. Carbon allotropes and derivatives occupy a unique place in terms of their ability to conduct heat. The room-temperature thermal conductivity of carbon materials span an extraordinary large range - of over five orders of magnitude - from the lowest in amorphous carbons to the highest in graphene and carbon nanotubes. I review thermal and thermoelectric properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder. A special attention is given to the unusual size dependence of heat conduction in two-dimensional crystals and, specifically, in graphene. I also describe prospects of applications of graphene and carbon materials for thermal management of electronics.Comment: Review Paper; 37 manuscript pages; 4 figures and 2 boxe

Spin-Dependent Transport in Fe/GaAs(100)/Fe Vertical Spin-Valves

The integration of magnetic materials with semiconductors will lead to the development of the next spintronics devices such as spin field effect transistor (SFET), which is capable of both data storage and processing. While the fabrication and transport studies of lateral SFET have attracted greatly attentions, there are only few studies of vertical devices, which may offer the opportunity for the future three-dimensional integration. Here, we provide evidence of two-terminal electrical spin injection and detection in Fe/GaAs/Fe vertical spin-valves (SVs) with the GaAs layer of 50 nanometers thick and top and bottom Fe electrodes deposited by molecular beam epitaxy. The spin-valve effect, which corresponds to the individual switching of the top and bottom Fe layers, is bias dependent and observed up to 20 K. We propose that the strongly bias-and temperature-dependent MR is associated with spin transport at the interfacial Fe/GaAs Schottky contacts and in the GaAs membranes, where balance between the barrier profiles as well as the dwell time to spin lifetime ratio are crucial factors for determining the device operations. The demonstration of the fabrication and spin injection in the vertical SV with a semiconductor interlayer is expected to open a new avenue in exploring the SFET

Transforaminal endoscopic surgery for symptomatic lumbar disc herniations: a systematic review of the literature

The study design includes a systematic literature review. The objective of the study was to evaluate the effectiveness of transforaminal endoscopic surgery and to compare this with open microdiscectomy in patients with symptomatic lumbar disc herniations. Transforaminal endoscopic techniques for patients with symptomatic lumbar disc herniations have become increasingly popular. The literature has not yet been systematically reviewed. A comprehensive systematic literature search of the MEDLINE and EMBASE databases was performed up to May 2008. Two reviewers independently checked all retrieved titles and abstracts and relevant full text articles for inclusion criteria. Included articles were assessed for quality and outcomes were extracted by the two reviewers independently. One randomized controlled trial, 7 non-randomized controlled trials and 31 observational studies were identified. Studies were heterogeneous regarding patient selection, indications, operation techniques, follow-up period and outcome measures and the methodological quality of these studies was poor. The eight trials did not find any statistically significant differences in leg pain reduction between the transforaminal endoscopic surgery group (89%) and the open microdiscectomy group (87%); overall improvement (84 vs. 78%), re-operation rate (6.8 vs. 4.7%) and complication rate (1.5 vs. 1%), respectively. In conclusion, current evidence on the effectiveness of transforaminal endoscopic surgery is poor and does not provide valid information to either support or refute using this type of surgery in patients with symptomatic lumbar disc herniations. High-quality randomized controlled trials with sufficiently large sample sizes are direly needed to evaluate if transforaminal endoscopic surgery is more effective than open microdiscectomy

Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

Deformation-induced localized solid-state amorphization in nanocrystalline nickel

Although amorphous structures have been widely obtained in various multi-component metallic alloys, amorphization in pure metals has seldom been observed and remains a long-standing scientific curiosity and technological interest. Here we present experimental evidence of localized solid-state amorphization in bulk nanocrystalline nickel introduced by quasi-static compression at room temperature. High-resolution electron microscope observations illustrate that nano-scale amorphous structures present at the regions where severe deformation occurred, e.g. along crack paths or surrounding nano-voids. These findings have indicated that nanocrystalline structures are highly desirable for promoting solid-state amorphization, which may provide new insights for understanding the nature of the crystalline-to-amorphous transformation and suggested a potential method to produce elemental metallic glasses that have hardly been available hitherto through rapid solidification