1,688 research outputs found

    Tunable circular dichroism through absorption in coupled optical modes of twisted triskelia nanostructures

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    We present a system consisting of two stacked chiral plasmonic nanoelements, so-called triskelia, that exhibits a high degree of circular dichroism. The optical modes arising from the interactions between the two elements are the main responsible for the dichroic signal. Their excitation in the absorption cross section is favored when the circular polarization of the light is opposite to the helicity of the system, so that an intense near-feld distribution with 3D character is excited between the two triskelia, which in turn causes the dichroic response. Therefore, the stacking, in itself, provides a simple way to tune both the value of the circular dichroism, up to 60%, and its spectral distribution in the visible and near infrared range. We show how these interaction-driven modes can be controlled by fnely tuning the distance and the relative twist angle between the triskelia, yielding maximum values of the dichroism at 20° and 100° for left- and right-handed circularly polarized light, respectively. Despite the three-fold symmetry of the elements, these two situations are not completely equivalent since the interplay between the handedness of the stack and the chirality of each single element breaks the symmetry between clockwise and anticlockwise rotation angles around 0°. This reveals the occurrence of clear helicity-dependent resonances. The proposed structure can be thus fnely tuned to tailor the dichroic signal for applications at will, such as highly efcient helicity-sensitive surface spectroscopies or single-photon polarization detectors, among others

    Reformulation of Pastry Products to Improve Effects on Health

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    Obesity is increasing at an alarming rate and has been described as a global pandemic. This increase has several explanations, including an increase in caloric intake, low levels of physical activity and the nutritional composition of our diets. In addition to public health policies based on healthy dietary patterns and recommendations based on the Mediterranean and other healthy diets, food reformulation, especially of commonly consumed processed foods, such as bakery products and pastries, is needed in the fight against obesity. Among nutritional reformulation strategies, reductions in caloric density, salt, added sugar, saturated and trans-fats are important in order to reduce the associated risk of developing chronic diseases, including cardiovascular diseases, diabetes and cancer

    Partitioning of trace elements in a entrained flow IGCC plant: Influence of selected operational conditions

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    The partitioning of trace elements and the influence of the feed conditions (50:50 coal/pet-coke feed blend and limestone addition) was investigated in this study. To this end feed fuel, fly ash and slag samples were collected under different operational conditions at the 335 MW Puertollano IGCC power plant (Spain) and subsequently analysed. The partitioning of elements in this IGCC plant may be summarised as follows: (a) high volatile elements (70–>99% in gas phase): Hg, Br, I, Cl and S; (b) moderately volatile elements (up to 40% in gas phase and 60% in fly ash): As, Sb, Se, B, F, Cd, Tl, Zn and Sn; (c) elements with high condensation potential: (>90% in fly ash): Pb, Ge, Ga and Bi; (d) elements enriched similarly in fly ash and slag 30–60% in fly ash: Cu, W, (P), Mo, Ni and Na; and (e) low volatile elements (>70% in slag): Cs, Rb, Co, K, Cr, V, Nb, Be, Hf, Ta, Fe, U, Ti, Al, Si, Y, Sr, Th, Zr, Mg, Ba, Mn, REEs, Ca and Li. The volatility of As, Sb, and Tl and the slagging of S, B, Cl, Cd and low volatile elements are highly influenced by the fuel geochemistry and limestone dosages, respectively

    Driving Magnetic Domains at the Nanoscale by Interfacial Strain-induced Proximity

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    We investigate the local nanoscale changes of the magnetic anisotropy of a Ni film subject to an inverse magnetostrictive effect by proximity to a V2O3 layer. Using temperature-dependent photoemission electron microscopy (PEEM) combined with X-ray magnetic circular dichroism (XMCD), direct images of the Ni spin alignment across the first-order structural phase transition (SPT) of V2O3 were obtained. We find an abrupt temperature-driven reorientation of the Ni magnetic domains across the SPT, which is associated with a large increase of the coercive field. Moreover, angular dependent ferromagnetic resonance (FMR) shows a remarkable change in the magnetic anisotropy of the Ni film across the SPT of V2O3. Micromagnetic simulations based on these results are in quantitative agreement with the PEEM data. Direct measurements of the lateral correlation length of the Ni domains from XMCD images show an increase of almost one order of magnitude at the SPT compared to room temperature, as well as a broad spatial distribution of the local transition temperatures, thus corroborating the phase coexistence of Ni anisotropies caused by the V2O3 SPT. We show that the rearrangement of the Ni domains is due to strain induced by the oxide layers' structural domains across the SPT. Our results illustrate the use of alternative hybrid systems to manipulate magnetic domains at the nanoscale, which allows for engineering of coercive fields for novel data storage architectures

    Doing good to do well? Corporate social responsibility reasons, practices and impacts in small and medium accommodation enterprises

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    Corporate social responsibility practices have been mostly analyzed in the large manufacturing business context, with little attention paid to the service sector and even less to small and medium-sized accommodation enterprises. This study aims to fill this gap through analyzing how these enterprises take responsibility. A survey of nearly 400 enterprises showed that the main reason for acting responsibly is altruistic, although competitiveness reasons are also important. Aspects of the " resource-based view" of the firm are validated through the positive impact of environmental cost-savings in financial performance, but also because other practices (not always related with economic reasons) are influencing their competitiveness. The article concludes that further implementation of these practices is necessary to achieve the full potential of competitive advantages. © 2011 Elsevier Ltd

    Paciente Masculino de 4 Años con Desnutrición Aguda Diagnosticado de Leishmaniasis Cutánea Diseminada en la Región Amazónica Ecuatoriana. Reporte de Caso

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    Leishmaniasis is an infectious disease caused by parasitism of cells of the mononuclear phagocytic system by flagellated protozoa belonging to the genus Leishmania, transmitted by Diptera insects belonging to the genus Phlebotomus in the Old World and Lutzomyia in the New World. They evolve clinically in humans in three forms: visceral, cutaneous, and mucocutaneous. These conditions are globally distributed. Those of the Old World are pure skin in the vast majority of cases and remit spontaneously in a few weeks to a few months. Those from the New World, due to multiple Leishmania complexes, have presented the highest risk of developing a secondary mucosal form. A case of a 4-year-old male patient with no significant history is reported, presenting ulcerative wounds located in the left cervical region and forearm of the left upper limb characteristic of Leishmania.La leishmaniasis es una enfermedad infecciosa causada por parasitismo de células del sistema fagocitario mononuclear por protozoos flagelados pertenecientes al género Leishmania, transmitida por insectos Díptera pertenecientes al género Phlebotomus en el Viejo Mundo y Lutzomyia en el Nuevo Mundo. Evolucionan clínicamente en humanos en tres formas: visceral, cutánea y mucocutáneo. Estas condiciones están distribuidas globalmente. Los del Viejo Mundo son pura piel en la gran mayoría de los casos y remiten espontáneamente en unas pocas semanas a unos pocos meses. Los del Nuevo mundo, debido a múltiples complejos de Leishmania, han presentado el mayor riesgo de desarrollar una forma mucosa secundaria. Se Reporta un caso de un paciente masculino de 4 años de edad sin antecedentes de importancia, presenta heridas ulcerosas localizadas en región cervical izquierda y antebrazo de miembro superior izquierdo característico de Leishmania

    Jaciments, ritmes i dinàmiques d'implantació i explotació del territori al neolític antic (5.500-4.500 cal BC) : el Pirineu i les serralades prepirinenques

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    La recerca sobre el neolític ha considerat fins fa relativament poc els Pirineus com un actor secundari en el procés d'introducció de les formes de vida agrícoles i ramaderes en contraposició a les serralades pre i litorals i de la depressió central. Els treballs realitzats en els darrers anys en aquests territoris, amb revisió de col·leccions antigues, excavacions preventives i nous projectes de recerca condueixen a obtenir una imatge molt més detallada i complexa del procés de neolitització de la preconcebuda. En aquest sentit els treballs duts a terme a l'alt Pirineu aporten dades d'un neolític incipient des del segon terç del vi mil·lenni cal BC en alçades properes als 2.000 metres, fet que obre una perspectiva de gran interès inèdita fa pocs anys. D'altra banda, projectes consolidats com el desenvolupat al jaciment de la Draga permeten proposar seqüenciacions regionals pel Prepirineu oriental per la introducció del neolític.Research on the Neolithic has until recently considered the Pyrenees as a secondary player in the process of introducing agricultural and livestock life forms as opposed to the pre- and coastal mountain ranges and the central depression. The work carried out in recent years in these territories, with a review of old collections, preventive excavations and new research projects, leads to a much more detailed and complex picture of the neolithic process of preconceived. In this sense, the work carried out in the high Pyrenees provides data from an incipient Neolithic since the second third of the sixth millennium cal BC at altitudes close to 2,000 meters, which opens a perspective of great interest unheard of a few years ago. On the other hand, consolidated projects such as the one developed at the Draga site make it possible to propose regional sequences for the eastern Pre-Pyrenees due to the introduction of the Neolithic

    Accuracy of colon capsule endoscopy in detecting colorectal polyps in individuals with familial colorectal cancer: could we avoid colonoscopies?

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    Background. Individuals with a family history of colorectal cancer (CRC) have an increased risk of CRC. We evaluated the diagnostic yield of CCE in the detection of lesions and also two different colon preparations. Methods. A prospective multicenter study was designed to assess CCE diagnostic yield in a cohort of asymptomatic individuals with a family history of CRC. CCE and colonoscopy were performed on the same day by 2 endoscopists who were blinded to the results of the other procedure. Results. Fifty-three participants were enrolled. The sensitivity, specificity, PPV, and NPV of CCE for detecting advanced adenomas were 100%, 98%, 67%, and 100%. Sensitivity, specificity, PPV, and NPV of CCE for the diagnosis of individuals with polyps were 87%, 97%, 93%, and 88%, respectively. CCE identify 100% of individuals with significant or advanced lesions. Overall cleanliness was adequate by 60.7% of them. The PEG-ascorbic boost seems to improve colon cleanliness, with similar colonic transit time. Conclusion. CCE is a promising tool, but it has to be considered as an alternative technique in this population in order to reduce the number of colonoscopies performed. More studies are needed to understand appropriate screening follow-up intervals and optimize the bowel preparation regimen

    Role of B Cell Profile for Predicting Secondary Autoimmunity in Patients Treated With Alemtuzumab

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    UDHEBRONTo explore if baseline blood lymphocyte profile could identify relapsing remitting multiple sclerosis (RRMS) patients at higher risk of developing secondary autoimmune adverse events (AIAEs) after alemtuzumab treatment. Multicenter prospective study including 57 RRMS patients treated with alemtuzumab followed for 3.25 [3.5-4.21] years, (median [interquartile range]). Blood samples were collected at baseline, and leukocyte subsets determined by flow cytometry. We had additional samples one year after the first cycle of alemtuzumab treatment in 39 cases. Twenty-two patients (38.6%) developed AIAEs during follow-up. They had higher B-cell percentages at baseline (p=0.0014), being differences mainly due to plasmablasts/plasma cells (PB/PC, p=0.0011). Those with no AIAEs had higher percentages of CD4+ T cells (p=0.013), mainly due to terminally differentiated (TD) (p=0.034) and effector memory (EM) (p=0.031) phenotypes. AIAEs- patients also showed higher values of TNF-alpha-producing CD8+ T cells (p=0.029). The percentage of PB/PC was the best variable to differentiate both groups of patients. Baseline values >0.10% closely associated with higher AIAE risk (Odds ratio [OR]: 5.91, 95% CI: 1.83-19.10, p=0.004). When excluding the 12 patients with natalizumab, which decreases blood PB/PC percentages, being the last treatment before alemtuzumab, baseline PB/PC >0.1% even predicted more accurately the risk of AIAEs (OR: 11.67, 95% CI: 2.62-51.89, p=0.0007). The AIAEs+ group continued having high percentages of PB/PC after a year of alemtuzumab treatment (p=0.0058). A PB/PC percentage <0.1% at baseline identifies MS patients at low risk of secondary autoimmunity during alemtuzumab treatment.

    High-resolution hepatitis C virus subtyping using NS5B deep sequencing and phylogeny, an alternative to current methods

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    HepatitisCvirus(HCV)is classified into seven major genotypesand67 subtypes. Recent studies haveshownthat inHCVgenotype 1-infected patients, response rates to regimens containingdirect-acting antivirals(DAAs)are subtype dependent. Currently available genotypingmethods have limited subtyping accuracy.Wehave evaluated theperformanceof adeep-sequencing-basedHCVsubtyping assay, developed for the 454/GS-Junior platform, in comparisonwith thoseof two commercial assays (VersantHCVgenotype 2.0andAbbott Real-timeHCVGenotype II)andusingdirectNS5Bsequencing as a gold standard (direct sequencing), in 114 clinical specimenspreviously tested by first-generation hybridization assay (82 genotype 1and32 with uninterpretable results). Phylogenetic analysis of deep-sequencing reads matched subtype 1 callingbypopulation Sanger sequencing(69%1b,31%1a) in 81 specimensandidentified amixed-subtype infection (1b/3a/1a) in one sample. Similarly,amongthe 32previously indeterminate specimens, identical genotypeandsubtype results were obtained by directanddeep sequencing in all but four samples with dual infection. In contrast, both VersantHCVGenotype 2.0andAbbott Real-timeHCVGenotype II failed subtype 1 calling in 13 (16%) samples eachandwere unable to identify theHCVgenotype and/or subtype inmore than half of the nongenotype 1 samples.Weconcluded that deep sequencing ismore efficient forHCVsubtyping than currently available methodsandallows qualitative identificationofmixed infectionsandmay bemorehelpfulwith respect to informing treatment strategies withnewDAA-containing regimens across allHCVsubtypesThis study has been supported by CDTI (Centro para el Desarrollo Tecnológico Industrial), Spanish Ministry of Economics and Competitiveness (MINECO), IDI-20110115; MINECO projects SAF 2009-10403; and also by the Spanish Ministry of Health, Instituto de Salud Carlos III (FIS) projects PI10/01505, PI12/01893, and PI13/00456. CIBERehd is funded by the Instituto de Salud Carlos III, Madrid, Spain. Work at CBMSO was supported by grant MINECO-BFU2011-23604, FIPSE, and Fundación Ramón Areces. X. Forns received unrestricted grant support from Roche and has acted as advisor for MSD, Gilead, and Abbvie. M. Alvarez-Tejado, J. Gregori, and J. M. Muñoz work in Roche Diagnostic
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