Reconfigurable phase-change meta-absorbers with on-demand quality factor control

This is the final version. Available on open access from Optical Society of America via the DOI in this recordData accessibility: Supporting data for this manuscript is available from the corresponding author.Perfect absorber type devices are well-suited to many applications, such as solar cells, spatial light modulators, bio-sensors, and highly-sensitive photo-detectors. In such applications, a method for the design and fabrication of devices in a simple and efficient way, while at the same time maintaining design control over the key performance characteristics of resonant frequency, reflection coefficient at resonance and quality factor, would be particularly advantageous. In this work we develop such a method, based on eigenmode analysis and critical coupling theory, and apply it to the design of reconfigurable phase-change metasurface absorber devices. To validate the method, the design and fabrication of a family of absorbers was carried out with a range of ‘on-demand’ quality factors, all operating at the same resonant frequency and able to be fabricated simply and simultaneously on the same chip. Furthermore, by switching the phase-change layer between its amorphous and crystalline states, we show that our devices can provide an active or reconfigurable functionality.Office of Naval Research (ONR)Engineering and Physical Sciences Research Council (EPSRC)Office of Naval Research (ONR

Early embryogenesis and organogenesis in the annelid Owenia fusiformis

Annelids are a diverse group of segmented worms within Spiralia, whose embryos exhibit spiral cleavage and a variety of larval forms. While most modern embryological studies focus on species with unequal spiral cleavage nested in Pleistoannelida (Sedentaria + Errantia), a few recent studies looked into Owenia fusiformis, a member of the sister group to all remaining annelids and thus a key lineage to understand annelid and spiralian evolution and development. However, the timing of early cleavage and detailed morphogenetic events leading to the formation of the idiosyncratic mitraria larva of O. fusiformis remain largely unexplored

ERK1/2 is an ancestral organising signal in spiral cleavage

Animal development is classified as conditional or autonomous based on whether cell fates are specified through inductive signals or maternal determinants, respectively. Yet how these two major developmental modes evolved remains unclear. During spiral cleavage—a stereotypic embryogenesis ancestral to 15 invertebrate groups, including molluscs and annelids—most lineages specify cell fates conditionally, while some define the primary axial fates autonomously. To identify the mechanisms driving this change, we study Owenia fusiformis, an early-branching, conditional annelid. In Owenia, ERK1/2-mediated FGF receptor signalling specifies the endomesodermal progenitor. This cell likely acts as an organiser, inducing mesodermal and posterodorsal fates in neighbouring cells and repressing anteriorising signals. The organising role of ERK1/2 in Owenia is shared with molluscs, but not with autonomous annelids. Together, these findings suggest that conditional specification of an ERK1/2(+) embryonic organiser is ancestral in spiral cleavage and was repeatedly lost in annelid lineages with autonomous development

Implementation of "wiki" philosophy to the update of teaching material in the area of pharmacy and pharmaceutical technology

La Directiva 2005/36/CE del Parlamento Europeo y del Consejo, relativa al reconocimiento decualificaciones profesionales, en su artículo 44, referente a la formación del farmacéutico, y la OrdenCIN/2137/2008, por la que se establecen los requisitos para la verificación de los títulos universitariosoficiales que habiliten para el ejercicio de esta profesión, recogen conocimientos y competencias quedeben contemplarse en su formación académica. Muchos de ellos están directamente relacionadoscon los fármacos y con los medicamentos y, por tanto, estrechamente vinculados con el Área deConocimiento de “Farmacia y Tecnología Farmacéutica”.Como profesores de esta Área desde hace muchos años, hemos apreciado la dificultad existente en lapreparación del material docente. Este hecho es debido a diversas razones. Entre ellas destacan: a)limitación de las fuentes documentales existentes sobre las propiedades físico-químicas ybiofarmacéuticas de muchos principios activos; b) escasez de textos concernientes a la fabricaciónconcreta de medicamentos; c) irrupción continua en el mercado de nuevos medicamentos, que implicaque muchos textos se queden desfasados; d) dispersión de los contenidos.Para intentar soslayar esta problemática, se han venido realizando diversas actividades docentes. Unade ellas, objeto de la presente comunicación, fue implantada en el curso 2009-10, para los alumnos de5º curso y se seguirá incluyendo en la programación docente para el próximo 2010-11. Está basada enel concepto “wiki”. Consiste en la elaboración, por parte de alumnos y profesores, de un espaciocomún, convenientemente organizado, donde todos aportan información para elaborar una granenciclopedia virtual sobre el medicamento.Directive 2005/36/EC of the European Parliament and Council on the recognition of professionalqualifications, section 44, concerning the formation of pharmacists, and the Order CIN/2137/2008,laying down the requirements for verification of official university degrees that prepare students towork in this profession, gather knowledge and skills to be covered in their education. Many of themare directly related to drugs and medicines and, therefore, closely linked to the Knowledge Area"Pharmacy and Pharmaceutical Technology”.As teachers of this area for many years, we have appreciated the difficulty in preparing the teachingmaterial. This is due to various reasons. These include: a) limitation of existing documentary sourceson the physico-chemical and biopharmaceutical characteristics of many active ingredients. b) ashortage of texts concerning the specific manufacture of medicaments. c) continuous irruption in themarket for new drugs and dosage forms, which means that many texts become outdated. d)information dispersion.To circumvent this problem, various educational activities have being conducted. One of this, objectof the present communication, was introduced in 2009-10 for students in the 5th grade and still be included in the course program for the next 2010-11. It is based on the concept of "wiki". It consistsof establishing, by students and teachers, a common area, conveniently organized in which all provideinformation to develop a virtual encyclopedia of medicaments

Reconfigurable multilevel control of hybrid all-dielectric phase-change metasurfaces

This is the final version. Available from Optical Society of America via the DOI in this record. All-dielectric metasurfaces comprising arrays of nanostructured high-refractive-index materials are re-imagining what is achievable in terms of the manipulation of light. However, the functionality of conventional dielectric-based metasurfaces is fixed by design; thus, their optical response is locked in at the fabrication stage. A far wider range of applications could be addressed if dynamic and reconfigurable control were possible. We demonstrate this here via the novel concept of hybrid metasurfaces, in which reconfigurability is achieved by embedding sub-wavelength inclusions of chalcogenide phase-change materials within the body of silicon nanoresonators. By strategic placement of an ultra-thin Ge 2 Sb 2 Te 5 Ge2Sb2Te5 layer and reversible switching of its phase-state, we show individual, multilevel, and dynamic control of metasurface resonances. We showcase our concept via the design, fabrication, and characterization of metadevices capable of dynamically filtering and modulating light in the near infrared (O and C telecom bands), with modulation depths as high as 70% and multilevel tunability. Finally, we show numerically how the same approach can be re-scaled to shorter wavelengths via appropriate material selection, paving the way to additional applications, such as high-efficiency vivid structural color generators in the visible spectrum. We believe that the concept of hybrid all-dielectric/phase-change metasurfaces presented in this work could pave the way for a wide range of design possibilities in terms of multilevel, reconfigurable, and high-efficiency light manipulation.Engineering and Physical Sciences Research Council (EPSRC)Russian Science FoundationRussian Foundation for Basic Researc

Effect of salt substitution on community-wide blood pressure and hypertension incidence

Replacement of regular salt with potassium-enriched substitutes reduces blood pressure in controlled situations, mainly among people with hypertension. We report on a population-wide implementation of this strategy in a stepped-wedge cluster randomized trial (NCT01960972). The regular salt in enrolled households was retrieved and replaced, free of charge, with a combination of 75% NaCl and 25% KCl. A total of 2,376 participants were enrolled in 6 villages in Tumbes, Peru. The fully adjusted intention-to-treat analysis showed an average reduction of 1.29 mm Hg (95% confidence interval (95% CI) (−2.17, −0.41)) in systolic and 0.76 mm Hg (95% CI (−1.39, −0.13)) in diastolic blood pressure. Among participants without hypertension at baseline, in the time- and cluster-adjusted model, the use of the salt substitute was associated with a 51% (95% CI (29%, 66%)) reduced risk of developing hypertension compared with the control group. In 24-h urine samples, there was no evidence of differences in sodium levels (mean difference 0.01; 95% CI (0.25, −0.23)), but potassium levels were higher at the end of the study than at baseline (mean difference 0.63; 95% CI (0.78, 0.47)). Our results support a case for implementing a pragmatic, population-wide, salt-substitution strategy for reducing blood pressure and hypertension incidence

Phase-change metadevices for the dynamic and reconfigurable control of light

This is the author accepted manuscript. The final version is available from Optical Society of America via the DOI in this recordNovel Optical Materials and Applications 2018, 2–5 July 2018, Zurich, SwitzerlandThe combination of chalcogenide phase-change materials with optical metamaterial arrays is exploited to create new forms of dynamic, tuneable and reconfigurable photonic devices including perfect absorbers, modulators, beam steerers and filters.CDW and VKN acknowledge ONRG funding (#N62909-16-1-2174). CDW, AMA, Y-YA, VKN acknowledge EPSRC funding EP/M015130/1 & EP/M015173/1. CrdeG, SG-CC, EG and LT the EPSRC CDT in Metamaterials (EP/L015331/1). LT acknowledges support from QinetiQ. MLG acknowledges EPSRC funding EP/M009033/1

Annelid functional genomics reveal the origins of bilaterian life cycles.

Indirect development with an intermediate larva exists in all major animal lineages1, which makes larvae central to most scenarios of animal evolution2-11. Yet how larvae evolved remains disputed. Here we show that temporal shifts (that is, heterochronies) in trunk formation underpin the diversification of larvae and bilaterian life cycles. We performed chromosome-scale genome sequencing in the annelid Owenia fusiformis with transcriptomic and epigenomic profiling during the life cycles of this and two other annelids. We found that trunk development is deferred to pre-metamorphic stages in the feeding larva of O. fusiformis but starts after gastrulation in the non-feeding larva with gradual metamorphosis of Capitella teleta and the direct developing embryo of Dimorphilus gyrociliatus. Accordingly, the embryos of O. fusiformis develop first into an enlarged anterior domain that forms larval tissues and the adult head12. Notably, this also occurs in the so-called 'head larvae' of other bilaterians13-17, with which the O. fusiformis larva shows extensive transcriptomic similarities. Together, our findings suggest that the temporal decoupling of head and trunk formation, as maximally observed in head larvae, facilitated larval evolution in Bilateria. This diverges from prevailing scenarios that propose either co-option9,10 or innovation11 of gene regulatory programmes to explain larva and adult origins

Conservative route to genome compaction in a miniature annelid

The causes and consequences of genome reduction in animals are unclear because our understanding of this process mostly relies on lineages with often exceptionally high rates of evolution. Here, we decode the compact 73.8-megabase genome of Dimorphilus gyrociliatus, a meiobenthic segmented worm. The D. gyrociliatus genome retains traits classically associated with larger and slower-evolving genomes, such as an ordered, intact Hox cluster, a generally conserved developmental toolkit and traces of ancestral bilaterian linkage. Unlike some other animals with small genomes, the analysis of the D. gyrociliatus epigenome revealed canonical features of genome regulation, excluding the presence of operons and trans-splicing. Instead, the gene-dense D. gyrociliatus genome presents a divergent Myc pathway, a key physiological regulator of growth, proliferation and genome stability in animals. Altogether, our results uncover a conservative route to genome compaction in annelids, reminiscent of that observed in the vertebrate Takifugu rubripes

Isolation of a wide range of minerals from a thermally treated plant: Equisetum arvense, a Mare’s tale

Silica is the second most abundant biomineral being exceeded in nature only by biogenic CaCO3. Many land plants (such as rice, cereals, cucumber, etc.) deposit silica in significant amounts to reinforce their tissues and as a systematic response to pathogen attack. One of the most ancient species of living vascular plants, Equisetum arvense is also able to take up and accumulate silica in all parts of the plant. Numerous methods have been developed for elimination of the organic material and/or metal ions present in plant material to isolate biogenic silica. However, depending on the chemical and/or physical treatment applied to branch or stem from Equisetum arvense; other mineral forms such glass-type materials (i.e. CaSiO3), salts (i.e. KCl) or luminescent materials can also be isolated from the plant material. In the current contribution, we show the chemical and/or thermal routes that lead to the formation of a number of different mineral types in addition to biogenic silica