Chirality-induced Spin Selectivity in Functionalized Carbon Nanotube Networks: The Role of Spin-orbit Coupling

Spin–orbit coupling in a chiral medium is generally assumed to be a necessary ingredient for the observation of the chirality-induced spin selectivity (CISS) effect. However, some recent studies have suggested that CISS may manifest even when the chiral medium has zero spin–orbit coupling. In such systems, CISS may arise due to an orbital polarization effect, which generates an electromagnetochiral anisotropy in two-terminal conductance. Here, we examine these concepts using a chirally functionalized carbon nanotube network as the chiral medium. A transverse measurement geometry is used, which nullifies any electromagnetochiral contribution but still exhibits the tell-tale signs of the CISS effect. This suggests that CISS may not be explained solely by electromagnetochiral effects. The role of nanotube spin–orbit coupling on the observed pure CISS signal is studied by systematically varying nanotube diameter. We find that the magnitude of the CISS signal scales proportionately with the spin–orbit coupling strength of the nanotubes. We also find that nanotube diameter dictates the supramolecular chirality of the medium, which in turn determines the sign of the CISS signal

Association between calcium intake, parathormone levels and blood pressure during pregnancy*

SUMMARY Purpose: To evaluate the association between calcium intake from diet, calciotropic hormones (PTH, PTH-rp), vasoactive regulators (endothelin, nitric oxide) and blood pressure levels during pregnancy, birth and puerperium. Method: In a prospective study 149 healthy normotensive primigravidas were followed-up from 15 weeks of gestation to puerperium. Daily calcium intake, calciuria, PTH, PTH-rp, endothelin, nitrite-nitrate, and Holter Test were assessed. Linear regression models were performed to evaluate the association between calcium intake, blood pressure levels and the laboratory tests. Multivariate regression models were performed to control potential confounders. Results: A significant increase of calcium intake during pregnancy was observed (931±301 mg/day to 1,195±467 mg/day, p<0.001). Plasma PTH-rp, endothelin, and nitrite-nitrate levels did not change during pregnancy. Among the women 38 (25.4%) had low calcium intake (<800 mg/day) with a larger increase of systolic and diastolic blood pressure during pregnancy (p=0.04) birth (p=0.006) and puerperium (p=0.01). After adjusting for other factors the multivariate analyses showed statistical association between low calcium intake, high parathormone levels and high systolic blood pressure levels during pregnancy (p=0.002). Conclusion: Low calcium intake during pregnancy is associated with a larger increase of systolic blood pressure and high parathormone levels. Keywords: Calcium intake; Endothelin; PTH: PTH-rp: Preeclampsia; Nitric oxide. Asociación entre consumo de calcio, niveles de parathormona y presión arterial en el embarazo RESUMEN Objetivo: Evaluar la asociación entre la ingesta de calcio en el embarazo, los niveles de presión arterial, las hormonas calciotrópicas (PTH, PTH-rp) y sustancias vasorreguladoras (endotelina, óxido nítrico). Métodos: Se realizó un estudio prospectivo con 149 primigrávidas normotensas que fueron incluidas en la semana 15 de gestación con seguimiento y evaluación hasta el puerperio. Se evaluó la ingesta diaria de calcio, la monitoría Holter de 24 horas, la calciuria, PTH, PTH-rp, la endotelina, nitritos y nitratos. Se siguieron modelos de regresión lineal para evaluar la asociación entre la ingesta de calcio, la presión arterial, las hormonas calciotrópicas y los vasorreguladores. Para controlar las variable

Oral Wine Texture Perception and Its Correlation with Instrumental Texture Features of Wine-Saliva Mixtures.

Unlike solid food, texture descriptors in liquid food are scarce, and they are frequently reduced to the term viscosity. However, in wines, apart from viscosity, terms, such as astringency, body, unctuosity and density, help describe their texture, relating the complexity and balance among their chemical components. Yet there is uncertainty about which wine components (and their combinations) cause each texture sensation and if their instrumental assessment is possible. Therefore, the aim of the present work was to study the effect of wine texture on its main components, when interacting with saliva. This was completed by using instrumental measurements of density and viscosity, and by using two types of panels (trained and expert). For that, six different model-wine formulations were prepared by adding one or multiple wine components: ethanol, mannoproteins, glycerol, and tannins to a de-alcoholised wine. All formulations were mixed with fresh human saliva (1:1), and their density and rheological properties were measured. Although there were no statistical differences, body perception was higher for samples with glycerol and/or mannoproteins, this was also correlated with density instrumental measurements (R = 0.971, p = 0.029). The viscosity of samples with tannins was the highest due to the formation of complexes between the model-wine and salivary proteins. This also provided astringency, therefore correlating viscosity and astringency feelings (R = 0.855, p = 0.030). No correlation was found between viscosity and body perception because of the overlapping of the phenolic components. Overall, the present results reveal saliva as a key factor when studying the wine texture through instrumental measurements (density and viscosity)

Interés terapéutico de las estatinas en el tratamiento de la aterosclerosis

Los inhibidores de la HMG-Co A reductasa o estatinas, son fármacos muy utilizados en el tratamiento de lahipercolesterolemia, ya que consiguen disminuir la concentración plamática de lipoproteína de baja densidad (LDL)regulando la síntesis endógena de colesterol y por tanto, de receptores para LDL.Recientemente se ha comprobado como el tratamiento prolongado con estos fármacos disminuyen la mortalidad ymorbilidad cardiovascular. Este fenómeno puede explicarse por los efectos beneficiosos directos de las estatinas enel desarrollo de la placa de ateroma. Las estatinas disminuyen la proliferación y migración de células de musculaturalisa vascular e inducen apoptosis de estas células. También previenen la oxidación de LDL y la formación de célulasespumosas, reducen la respuesta inflamatoria asociada a la aterosclerosis, normalizan los fenómenos de coagulacióny fibrinolisis y por último mejoran significativamente la función endotelial. Todas estas propiedades parecen estarmediadas compuestos isoprenoides intermediarios de la ruta metabólica de la HMG-Co A reductasa, y son independientesde la concentración de colesterol en el medio.Por tanto, las estatinas también podrían ser utilizadas en enfermedades asociadas a disfunción endotelial independientementede las cifras analíticas de LDL, tal y como sucede en la hipertensión

Cross-Modal Plasticity in Cuban Visually-Impaired Child Cochlear Implant Candidates: Topography of Somatosensory Evoked Potentials

ABSTRACT INTRODUCTION Studies of neuroplasticity have shown that the brain's neural networks change in the absence of sensory input such as hearing or vision. However, little is known about what happens when both sensory modalities are lost (deaf-blindness). Hence, this study of cortical reorganization in visually-impaired child cochlear implant (CI) candidates

New insights into the Manila clam – Perkinsus olseni interaction based on gene expression analysis of clam hemocytes and parasite trophozoites through in vitro challenges

The Manila clam (Ruditapes philippinarum) is the bivalve species with the highest global production from both fisheries and aquaculture, but its production is seriously threatened by perkinsosis, a disease caused by the protozoan parasite Perkinsus olseni. To understand the molecular mechanisms underlying R. philippinarum–P. olseni interactions, we analysed the gene expression profiles of in vitro challenged clam hemocytes and P. olseni trophozoites, using two oligo-microarray platforms, one previously validated for R. philippinarum hemocytes and a new one developed and validated in this study for P. olseni. Manila clam hemocytes were in vitro challenged with trophozoites, zoospores, and extracellular products from P. olseni in vitro cultures, while P. olseni trophozoites were in vitro challenged with Manila clam plasma along the same time-series (1 h, 8 h, and 24 h). The hemocytes showed a fast activation of the innate immune response, particularly associated with hemocyte recruitment, in the three types of challenges. Nevertheless, different immune-related pathways were activated in response to the different parasite stages, suggesting specific recognition mechanisms. Furthermore, the analyses provided useful complementary data to previous in vivo challenges, and confirmed the potential of some proposed biomarkers. The combined analysis of gene expression in host and parasite identified several processes in both the clam and P. olseni, such as redox and glucose metabolism, protease activity, apoptosis and iron metabolism, whose modulation suggests cross-talk between parasite and host. This information might be critical to determine the outcome of the infection, thus highlighting potential therapeutic targets. Altogether, the results of this study aid understanding the response and interaction between R. philippinarum and P. olseni, and will contribute to developing effective control strategies for this threatening parasitosisThis work was funded by the Ministerio de Economía y Competitividad of the Spanish Government, through the projects (AGL2011-30449-C02-01 and AGL2012-37981), the European Regional Development Funds (FEDER 2007–2013) and the Regional Government of Galicia, Xunta de Galicia, Spain, through the projects ED431C 2018/28 and ED431D 2017/21. The study was also supported by the Centro de Supercomputación de Galicia (CESGA). The first author would like to acknowledge the PhD scholarship awarded by the EXPERTS III Consortium of the European Community Mobility Programme “Erasmus Mundus Action 2, Strand 1” (EMA2). SFB was supported by a scholarship of the Consellería do Mar da Xunta de GaliciaS

Mitochondrial echoes of first settlement and genetic continuity in El Salvador

Background: From Paleo-Indian times to recent historical episodes, the Mesoamerican isthmus played an important role in the distribution and patterns of variability all around the double American continent. However, the amount of genetic information currently available on Central American continental populations is very scarce. In order to shed light on the role of Mesoamerica in the peopling of the New World, the present study focuses on the analysis of the mtDNA variation in a population sample from El Salvador. Methodology/Principal Findings: We have carried out DNA sequencing of the entire control region of the mitochondrial DNA (mtDNA) genome in 90 individuals from El Salvador. We have also compiled more than 3,985 control region profiles from the public domain and the literature in order to carry out inter-population comparisons. The results reveal a predominant Native American component in this region: by far, the most prevalent mtDNA haplogroup in this country (at ~90%) is A2, in contrast with other North, Meso- and South American populations. Haplogroup A2 shows a star-like phylogeny and is very diverse with a substantial proportion of mtDNAs (45%; sequence range 16090–16365) still unobserved in other American populations. Two different Bayesian approaches used to estimate admixture proportions in El Salvador shows that the majority of the mtDNAs observed come from North America. A preliminary founder analysis indicates that the settlement of El Salvador occurred about 13,400±5,200 Y.B.P.. The founder age of A2 in El Salvador is close to the overall age of A2 in America, which suggests that the colonization of this region occurred within a few thousand years of the initial expansion into the Americas. Conclusions/Significance: As a whole, the results are compatible with the hypothesis that today's A2 variability in El Salvador represents to a large extent the indigenous component of the region. Concordant with this hypothesis is also the observation of a very limited contribution from European and African women (~5%). This implies that the Atlantic slave trade had a very small demographic impact in El Salvador in contrast to its transformation of the gene pool in neighbouring populations from the Caribbean facade

Experimental assessment and validation of inertial behaviour of virtual synchronous machines

Increasing integration of converter-interfaced renewable generation has led to significant operational challenges for power systems. Such challenges are mainly caused by the different capabilities and dynamic responses of the converters compared with synchronous machines, for example, converters do not naturally provide inertia to the system. Virtual Synchronous Machine (VSM) is considered as a promising solution to address the challenges associated with reduced system inertia via the provision of emulated inertial response to support the operation of converter-dominated power systems. However, it has been observed that the dynamic behaviour of the VSM could differ significantly from that of a Synchronous Condenser (SC) and a Synchronous Generator (SG) in terms of inertial response provision, even when the VSM is configured with the same inertia constant. Furthermore, effective practical methods for evaluating the damping performance of VSMs are not presently available. To gain a better understanding and achieve a more accurate assessment of the dynamic inertial and damping performance of VSMs, this paper presents an experimental methodology for systematic evaluation of the dynamic response of the VSM in the frequency domain using the Network Frequency Perturbation (NFP) method. Experimental design and implementation of the NFP method are presented to assess VSM system's equivalent inertia and damping constants, where the VSM system under test can be treated as a black box without any knowledge of internal settings and control design. Case studies are conducted, where the proposed experimental design has been applied for testing and assessing the inertial and damping constants of a physical 246 kVA VSM prototype driven by a Battery Energy Storage System with comparison of the SC and SG with equivalent inertia constant. Power-Hardware-in-the-Loop (PHiL) testing is also conducted to demonstrate the VSM's inertia performance. The studies demonstrate that the developed experimental approach based on NFP method provides a valuable tool for network operators and manufacturers for evaluating the inertial and damping performance

Doubling up on supersymmetry in the Higgs sector

We explore the possibility that physics at the TeV scale possesses approximate N =2 supersymmetry, which is reduced to the N =1 minimal supersymmetric extension of the Standard Model (MSSM) at the electroweak scale. This doubling of supersymmetry modifies the Higgs sector of the theory, with consequences for the masses, mixings and couplings of the MSSM Higgs bosons, whose phenomenological consequences we explore in this paper. The mass of the lightest neutral Higgs boson h is independent of tan β at the tree level, and the decoupling limit is realized whatever the values of the heavy Higgs boson masses. Radiative corrections to the top quark and stop squarks dominate over those due to particles in N = 2 gauge multiplets. We assume that these radiative corrections fix mh ≃ 125 GeV, whatever the masses of the other neutral Higgs bosons H, A, a scenario that we term the h2MSSM. Since the H, A bosons decouple from the W and Z bosons in the h2MSSM at tree level, only the LHC constraints on H, A and H± couplings to fermions are applicable. These and the indirect constraints from LHC measurements of h couplings are consistent with mA ≳ 200 GeV for tan β ∈ (2, 8) in the h2MSSM

Minisequencing mitochondrial DNA pathogenic mutations

<p>Abstract</p> <p>Background</p> <p>There are a number of well-known mutations responsible of common mitochondrial DNA (mtDNA) diseases. In order to overcome technical problems related to the analysis of complete mtDNA genomes, a variety of different techniques have been proposed that allow the screening of coding region pathogenic mutations.</p> <p>Methods</p> <p>We here propose a minisequencing assay for the analysis of mtDNA mutations. In a single reaction, we interrogate a total of 25 pathogenic mutations distributed all around the whole mtDNA genome in a sample of patients suspected for mtDNA disease.</p> <p>Results</p> <p>We have detected 11 causal homoplasmic mutations in patients suspected for Leber disease, which were further confirmed by standard automatic sequencing. Mutations m.11778G>A and m.14484T>C occur at higher frequency than expected by change in the Galician (northwest Spain) patients carrying haplogroup J lineages (Fisher's Exact test, <it>P</it>-value < 0.01). The assay performs well in mixture experiments of wild:mutant DNAs that emulate heteroplasmic conditions in mtDNA diseases.</p> <p>Conclusion</p> <p>We here developed a minisequencing genotyping method for the screening of the most common pathogenic mtDNA mutations which is simple, fast, and low-cost. The technique is robust and reproducible and can easily be implemented in standard clinical laboratories. </p