On the use of bianisotropic huygens' metasurfaces to build leaky-wave antennas

The Electromagnetics AcademyHuygens' metasurfaces are considered a powerful tool to achieve anomalous electromagnetic field transformations. They consist of an artifcial surface built of pairs of collocated electric and magetic dipoles that force the boundary conditions for the desired transformation to be ful lled [1]. Despite their possibilities, the achievable transformations must ful l some conditions. In [2] it was shown that Huygens' metasurfaces with passive and lossless particles can achieve an arbitrary field transformation provided that the power is conserved at each point of the metasurface and there is wave impedance matching. However, it was shown in [3], that by introducing bianisotropy of the omega-type, the matching condition can be suppressed, which allows the control of both the transmission and rejection coe cients on the metasurface.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Origin of the biphase nature and surface roughness of biogenic calcite secreted by the giant barnacle Austromegabalanus psittacus

The calcite grains forming the wall plates of the giant barnacle Austramegabalanus psittacus have a distinctive surface roughness made of variously sized crystalline nanoprotrusions covered by extremely thin amorphous pellicles. This biphase (crystalline-amorphous) structure also penetrates through the crystal’s interiors, forming a web-like structure. Nanoprotrusions very frequently elongate following directions related to the crystallographic structure of calcite, in particular, the directions, which are the strongest periodic bond chains (PBCs) in calcite. We propose that the formation of elongated nanoprotrusions happens during the crystallization of calcite from a precursor amorphous calcium carbonate (ACC). This is because biomolecules integrated within the ACC are expelled from such PBCs due to the force of crystallization, with the consequent formation of uninterrupted crystalline nanorods. Expelled biomolecules accumulate in adjacent regions, thereby stabilizing small pellicle-like volumes of ACC. With growth, such pellicles become occluded within the crystal. In summary, the surface roughness of the biomineral surface reflects the complex shape of the crystallization front, and the biphase structure provides evidence for crystallization from an amorphous precursor. The surface roughness is generally explained as resulting from the attachment of ACC particles to the crystal surface, which later crystallised in concordance with the crystal lattice. If this was the case, the nanoprotrusions do not reflect the size and shape of any precursor particle. Accordingly, the particle attachment model for biomineral formation should seek new evidence.Instituto de Salud Carlos III Spanish Government CGL2017-85118-P CGL2015-64683-PUnidad Cientifica de Excelencia of the University of Granada UCE-PP2016-05Junta de Andalucía RNM363ANID-Chile FONDECYT 1140938 PCI ANID REDES 170106 PIA ANID ANILLOS ACT17203

Echium acanthocarpum hairy root cultures, a suitable system for polyunsaturated fatty acid studies and production

<p>Abstract</p> <p>Background</p> <p>The therapeutic and health promoting role of highly unsaturated fatty acids (HUFAs) from fish, <it>i.e. </it>eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) are well known. These same benefits may however be shared by some of their precursors, the polyunsaturated fatty acids (PUFAs), such as stearidonic acid (SDA, 18:4 n-3). In order to obtain alternative sources for the large-scale production of PUFAs, new searches are being conducted focusing on higher plants oils which can contain these n-3 and n-6 C18 precursors, <it>i.e. </it>SDA and GLA (18:3n-6, γ-linolenic acid).</p> <p>Results</p> <p>The establishment of the novel <it>Echium acanthocarpum </it>hairy root cultures represents a powerful tool in order to research the accumulation and metabolism of fatty acids (FAs) in a plant particularly rich in GLA and SDA. Furthermore, this study constitutes the first example of a <it>Boraginaceae </it>species hairy root induction and establishment for FA studies and production. The dominant PUFAs, 18:2n-6 (LA, linoleic acid) and 18:3n-6 (GLA), accounted for about 50% of total FAs obtained, while the n-3 PUFAs, 18:3n-3 (ALA, α-linolenic acid) and 18:4n-3 (SDA), represented approximately 5% of the total. Production of FAs did not parallel hairy root growth, and the optimal productivity was always associated with the highest biomass density during the culture period. Assuming a compromise between FA production and hairy root biomass, it was determined that sampling times 4 and 5 gave the most useful FA yields. Total lipid amounts were in general comparable between the different hairy root lines (29.75 and 60.95 mg/g DW), with the major lipid classes being triacylglycerols. The FAs were chiefly stored in the hairy roots with very minute amounts being released into the liquid nutrient medium.</p> <p>Conclusions</p> <p>The novel results presented here show the utility and high potential of <it>E. acanthocarpum </it>hairy roots. They are capable of biosynthesizing and accumulating a large range of polyunsaturated FAs, including the target GLA and SDA fatty acids in appreciable quantities.</p

Coherent generation of nonclassical light on chip via detuned photon blockade

The on-chip generation of non-classical states of light is a key-requirement for future optical quantum hardware. In solid-state cavity quantum electrodynamics, such non-classical light can be generated from self-assembled quantum dots strongly coupled to photonic crystal cavities. Their anharmonic strong light-matter interaction results in large optical nonlinearities at the single photon level, where the admission of a single photon into the cavity may enhance (photon-tunnelling) or diminish (photon-blockade) the probability for a second photon to enter the cavity. Here, we demonstrate that detuning the cavity and QD resonances enables the generation of high-purity non-classical light from strongly coupled systems. For specific detunings we show that not only the purity but also the efficiency of single-photon generation increases significantly, making high-quality single-photon generation by photon-blockade possible with current state-of-the-art samples.Comment: Phys. Rev. Lett. in pres

Bgs4 is essential for cytokinesis and cell growth

[EN]Schizosaccharomyces pombe contains four putative (1,3)β-D-glucan synthase (GS) catalytic subunits, Bgs1p to Bgs4p. In this work, we cloned bgs4+ and show that Bgs4p is the only subunit 1) essential for maintaining cell integrity during both cytokinesis and polarized growth, and 2) found to be part of the GS enzyme. Here we show that bgs4+, cwg1+ (cwg1-1 shows reduced cell-wall β-glucan and GS catalytic activity) and orb11+ (orb11-59 is defective in cell morphogenesis) are the same gene. bgs4+ is essential during spore germination. bgs4+ shut-off produces cell lysis at growing poles and mainly at the septum prior to cytokinesis, suggesting that Bgs4p is essential for cell wall growth and for compensating an excess of cell wall degradation during cytokinesis. Shut-off and overexpression analysis suggest that 1) Bgs4p forms part of a GS catalytic multiprotein complex, and 2) Bgs4p-promoted cell-wall β-glucan alterations induce compensatory mechanisms from other Bgs subunits and (1,3)α-D-glucan synthase. Physiological localization studies showed that Bgs4p localizes to the growing ends, the medial ring and septum, and in each process of wall synthesis or remodeling that occurs during sexual differentiation: mating, zygote and spore formation, and spore germination. Bgs4p timing and requirements for proper positioning during cytokinesis and its localization pattern during spore maturation differ from those of Bgs1p. Bgs4p localizes overlapping the contractile ring once Bgs1p is present and a Calcofluor white-stained septum material is detected, suggesting that Bgs4p is involved in a late process of secondary or general septum synthesis. Unlike Bgs1p, Bgs4p needs the medial ring but not the Septation Initiation Network proteins to localize with the other septation components. Furthermore, Bgs4p localization depends on the polarity establishment proteins. Finally, F-actin is necessary for Bgs4p delocalization from and relocalization to the growing regions, but it is not needed for its stable maintenance at the growing sites, poles and septum. All these data show for the first time an essential role for a Bgs subunit in the synthesis of a (1,3)β-D-glucan necessary to preserve cell integrity when cell wall synthesis or repair are needed

Continuous culture methodology for the screening of microalgae for oil

A basic criterion in the selection of microalgae suitable as source of oil for biodiesel should be their actual capacity to produce lipids or, more properly, the fatty acid yield. Performance assessment of ten preselected microalgae under both batch and continuous culture points to the latter approach as the most adequate for evaluating fatty acid productivity. Differences were patent in continuous culture among strains that otherwise had analogous oil accumulation potential under batch culture. Some promising strains under batch culture (like Muriella aurantiaca and Monoraphidium braunii) exhibited, however, values for actual fatty acid productivity lower than 40 mg L-1d-1 in continuous regime. The analysis performed in photochemostat under continuous culture regime revealed the great potential of Chlorococcum olefaciens, Pseudokirchneriella subcapitata and Scenedesmus almeriensis as oil producing microalgae. Fatty acid productivity levels over 90 mg L-1d-1 were recorded for the latter strains under moderate nitrogen limitation, conditions which led to an enrichment in saturated and monounsaturated fatty acids, a more suitable profile as raw material for biodiesel. The continuous culture methodology employed represents a sound procedure for screening microalgae for biofuel production, providing a reliable evaluation of their fatty acid production capacity, under conditions close to those of outdoor production systemsEspaña MCINN Project CTQ2008-06741-CO2-02/PP

African Swine Fever Virus Uses Macropinocytosis to Enter Host Cells

African swine fever (ASF) is caused by a large and highly pathogenic DNA virus, African swine fever virus (ASFV), which provokes severe economic losses and expansion threats. Presently, no specific protection or vaccine against ASF is available, despite the high hazard that the continued occurrence of the disease in sub-Saharan Africa, the recent outbreak in the Caucasus in 2007, and the potential dissemination to neighboring countries, represents. Although virus entry is a remarkable target for the development of protection tools, knowledge of the ASFV entry mechanism is still very limited. Whereas early studies have proposed that the virus enters cells through receptor-mediated endocytosis, the specific mechanism used by ASFV remains uncertain. Here we used the ASFV virulent isolate Ba71, adapted to grow in Vero cells (Ba71V), and the virulent strain E70 to demonstrate that entry and internalization of ASFV includes most of the features of macropinocytosis. By a combination of optical and electron microscopy, we show that the virus causes cytoplasm membrane perturbation, blebbing and ruffles. We have also found that internalization of the virions depends on actin reorganization, activity of Na+/H+ exchangers, and signaling events typical of the macropinocytic mechanism of endocytosis. The entry of virus into cells appears to directly stimulate dextran uptake, actin polarization and EGFR, PI3K-Akt, Pak1 and Rac1 activation. Inhibition of these key regulators of macropinocytosis, as well as treatment with the drug EIPA, results in a considerable decrease in ASFV entry and infection. In conclusion, this study identifies for the first time the whole pathway for ASFV entry, including the key cellular factors required for the uptake of the virus and the cell signaling involved

Characterization of the African swine fever virus decapping enzyme during infection

African swine fever virus (ASFV) infection is characterized by a progressive decrease in cellular protein synthesis with a concomitant increase in viral protein synthesis, though the mechanism by which the virus achieves this is still unknown. Decrease of cellular mRNA is observed during ASFV infection, suggesting that inhibition of cellular proteins is due to an active mRNA degradation process. ASFV carries a gene (Ba71V D250R/Malawi g5R) that encodes a decapping protein (ASFV-DP) that has a Nudix hydrolase motif and decapping activity in vitro. Here, we show that ASFV-DP was expressed from early times and accumulated throughout the infection with a subcellular localization typical of the endoplasmic reticulum, colocalizing with the cap structure and interacting with the ribosomal protein L23a. ASFV-DP was capable of interaction with poly(A) RNA in cultured cells, primarily mediated by the N-terminal region of the protein. ASFV-DP also interacted with viral and cellular RNAs in the context of infection, and its overexpression in infected cells resulted in decreased levels of both types of transcripts. This study points to ASFV-DP as a viral decapping enzyme involved in both the degradation of cellular mRNA and the regulation of viral transcripts

Detoxifying enzymes at the cross-roads of inflammation, oxidative stress, and drug hypersensitivity: role of glutathione transferase P1-1 and aldose reductase

9 p.-2 figPhase I and II enzymes are involved in the metabolism of endogenous reactive compounds as well as xenobiotics, including toxicants and drugs. Genotyping studies have established several drug metabolizing enzymes as markers for risk of drug hypersensitivity. However, other candidates are emerging that are involved in drug metabolism but also in the generation of danger or costimulatory signals. Enzymes such as aldo-keto reductases (AKR) and glutathione transferases (GST) metabolize prostaglandins and reactive aldehydes with proinflammatory activity, as well as drugs and/or their reactive metabolites. In addition, their metabolic activity can have important consequences for the cellular redox status, and impacts the inflammatory response as well as the balance of inflammatory mediators, which can modulate epigenetic factors and cooperate or interfere with drug-adduct formation. These enzymes are, in turn, targets for covalent modification and regulation by oxidative stress, inflammatory mediators, and drugs. Therefore, they constitute a platform for a complex set of interactions involving drug metabolism, protein haptenation, modulation of the inflammatory response, and/or generation of danger signals with implications in drug hypersensitivity reactions. Moreover, increasing evidence supports their involvement in allergic processes. Here, we will focus on GSTP1-1 and aldose reductase (AKR1B1) and provide a perspective for their involvement in drug hypersensitivityThis work has been supported by grants SAF2012-36519 from MINECO and SAF-2015-68590-R from MINECO/FEDER and ISCIII RETIC RIRAAF RD12/0013/0008 to DP,and RD12/0013/0002 to J A.Peer reviewe

Impact of the new handling recommendations for hazardous drugs in a hospital pharmacy service

Objective: To describe the actions taken by the Pharmacy Unit in a tertiary hospital in order to adapt to the recommendations established by NIOSH 2014 for handling Hazardous Drugs. Method: A retrospective observational study. A list was prepared including all hazardous drugs according to NIOSH 2014 that were available at the hospital as marketed or foreign drugs, or used in clinical trials, and there was a review of the processes of acquisition, repackaging, preparation, circuits, organizational, dispensing and identification. Results: After the analysis, a report including all needs was prepared and sent to the Hospital Management. Any relevant information about the handling and administration of hazardous drugs was included in the prescription computer program. There were changes in the acquisition process of two drugs, in order to avoid splitting and multi-dose formulations. An alternative or improvement was found for 35 253 of the 75 779 units of hazardous drugs repackaged in one year. The Pharmacy Unit took over the preparation of four non-sterile medications, as well as the preparation of all sterile parenteral medications included in Lists 1 and 2 that were not previously prepared there, as well as one from List 3. Information was also included about the preparation processes of Magistral Formulations that involved hazardous drugs from Lists 2 or 3