569 research outputs found

    Contrast Enhancement of Optical Coherence Tomography Images Using Branched Gold Nanoparticles

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    We propose the use of branched gold nanoparticles (B-GNPs) as a contrast agent for optical coherence tomography (OCT) imaging. Our results show that even when the central source of our OCT (1325 nm) is too far from the maximum peak of the plasmon resonance, branched nanoparticles scatter light very efficiently at this wavelength. B-GNPs were tested as a contrast agent in water and agarose-TiO2 tissue phantoms; the estimated increments in contrast were 9.19 dB and 15.07 dB for branched nanoparticles in water with concentrations of 2.2×109 NPs/mL and 6.6×109 NPs/mL, respectively, while for agarose-TiO2 tissue phantoms the estimated value was 3.17 dB. These results show the promising application of B-GNPs as a contrast agent for tissue imaging using OCT, not only for sources at 1325 nm but also at other central wavelengths located between 800 and 1000 nm

    Encofrado perdido constituido por paja cohesionada con micelio como sustituto del poliestireno expandido

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    This paper presents some of the physical and mechanical properties of a material made of mycelium within wheat straw. The aim of this study is to take advantage of the excellent properties of the cellular walls of fungi, made of chitin, an organic substance very abundant in the nature that presents notable mechanical properties both to compete with very contaminant plastics usually used in construction, like expanded polystyrene, and to substitute them, as this new material is biodegradable too. First simple compression essays carried out on the mentioned conglomerate made of mycelium within wheat straw provide promising mechanical strength results.En esta publicación se presentan algunas de las cualidades físicas y mecánicas de un material constituido por micelio sobre sustrato a base de paja de trigo. El objetivo es aprovechar las bondades de las paredes celulares del hongo, compuestas por quitina, una sustancia orgánica muy abundante en la naturaleza y que presenta unas excelentes propiedades mecánicas que convierten este material en idóneo, no sólo para competir con los contaminantes plásticos tan tradicionalmente empleados en construcción, tales como el poliestireno, sino para sustituirlos, puesto que el compuesto es totalmente biodegradable. Los primeros ensayos a compresión simple efectuados sobre este conglomerado formado por el sustrato y la quitina arrojan resultados de resistencia mecánica prometedores

    Towards a Greener and Scalable Synthesis of Na2_{2}Ti6_{6}O13_{13} Nanorods and Their Application as Anodes in Batteries for Grid-Level Energy Storage

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    Grid applications require high power density (for frequency regulation, load leveling, and renewable energy integration), achievable by combining multiple batteries in a system without strict high capacity requirements. For these applications however, safety, cost efficiency, and the lifespan of electrode materials are crucial. Titanates, safe and longevous anode materials providing much lower energy density than graphite, are excellent candidates for this application. The innovative molten salt synthesis approach proposed in this work provides exceptionally pure Na2_{2}Ti6_{6}O13_{13} nanorods generated at 900–1100 °C in a yield ≥80 wt%. It is fast, cost‐efficient, and suitable for industrial upscaling. Electrochemical tests reveal stable performance providing capacities of ≈100 mA h g1^{-1} (Li) and 40 mA h g1^{-1} (Na). Increasing the synthesis temperature to 1100 °C leads to a capacity decrease, most likely resulting from 1) the morphology/volume change with the synthesis temperature and 2) distortion of the Na2_{2}Ti6_{6}O13_{13} tunnel structure indicated by electron energy‐loss and Raman spectroscopy. The suitability of pristine Na2_{2}Ti6_{6}O13_{13} as the anode for grid‐level energy storage systems has been proven a priori, without any performance‐boosting treatment, indicating considerable application potential especially due to the high yield and low cost of the synthesis route

    Recomendaciones basadas en la evidencia del grupo andaluz para la reflexión e investigación en nutrición (Garin) para el manejo del paciente con síndrome de intestino corto

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    In order to develop evidence-based recommendations and expert consensus for the nutritional management of patients with short bowel syndrome (SBS), we conducted a systematic literature search using the PRISMA methodology plus a critical appraisal following the GRADE scale procedures. Pharmacological treatment with antisecretory drugs, antidiarrheal drugs, and somatostatin contributes to reducing intestinal losses. Nutritional support is based on parenteral nutrition; however, oral intake and/or enteral nutrition should be introduced as soon as possible. In the chronic phase, the diet should have as few restrictions as possible, and be adapted to the SBS type. Home parenteral nutrition (HPN) should be individualized. Single-lumen catheters are recommended and taurolidine should be used for locking the catheter. The HPN’s lipid content must be greater than 1 g/kg per week but not exceed 1 g/kg per day, and omega-6 fatty acids (ω6 FAs) should be reduced. Trace element vials with low doses of manganese should be used. Patients with chronic SBS who require long-term HPN/fluid therapy despite optimized treatment should be considered for teduglutide treatment. All patients require a multidisciplinary approach and specialized follow-up. These recommendations and suggestions regarding nutritional management in SBS patients have direct clinical applicability

    Towards engineering the perfect defect in high-performing permanent magnets

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    Permanent magnets draw their properties from a complex interplay, across multiple length scales, of the composition and distribution of their constituting phases, that act as building blocks, each with their associated intrinsic properties. Gaining a fundamental understanding of these interactions is hence key to decipher the origins of their magnetic performance and facilitate the engineering of better-performing magnets, through unlocking the design of the "perfect defects" for ultimate pinning of magnetic domains. Here, we deployed advanced multiscale microscopy and microanalysis on a bulk Sm2(CoFeCuZr)17 pinning-type high-performance magnet with outstanding thermal and chemical stability. Making use of regions with different chemical compositions, we showcase how both a change in the composition and distribution of copper, along with the atomic arrangements enforce the pinning of magnetic domains, as imaged by nanoscale magnetic induction mapping. Micromagnetic simulations bridge the scales to provide an understanding of how these peculiarities of micro- and nanostructure change the hard magnetic behaviour of Sm2(CoFeCuZr)17 magnets. Unveiling the origins of the reduced coercivity allows us to propose an atomic-scale defect and chemistry manipulation strategy to define ways toward future hard magnets

    Simultaneous measurement of the ratio B(t->Wb)/B(t->Wq) and the top quark pair production cross section with the D0 detector at sqrt(s)=1.96 TeV

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    We present the first simultaneous measurement of the ratio of branching fractions, R=B(t->Wb)/B(t->Wq), with q being a d, s, or b quark, and the top quark pair production cross section sigma_ttbar in the lepton plus jets channel using 0.9 fb-1 of ppbar collision data at sqrt(s)=1.96 TeV collected with the D0 detector. We extract R and sigma_ttbar by analyzing samples of events with 0, 1 and >= 2 identified b jets. We measure R = 0.97 +0.09-0.08 (stat+syst) and sigma_ttbar = 8.18 +0.90-0.84 (stat+syst)} +/-0.50 (lumi) pb, in agreement with the standard model prediction.Comment: submitted to Phys.Rev.Letter

    Measurement of the B0_s semileptonic branching ratio to an orbitally excited D_s** state, Br(B0_s -> Ds1(2536) mu nu)

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    In a data sample of approximately 1.3 fb-1 collected with the D0 detector between 2002 and 2006, the orbitally excited charm state D_s1(2536) has been observed with a measured mass of 2535.7 +/- 0.6 (stat) +/- 0.5 (syst) MeV via the decay mode B0_s -> D_s1(2536) mu nu X. A first measurement is made of the branching ratio product Br(b(bar) -> D_s1(2536) mu nu X).Br(D_s1(2536)->D* K0_S). Assuming that D_s1(2536) production in semileptonic decay is entirely from B0_s, an extraction of the semileptonic branching ratio Br(B0_s -> D_s1(2536) mu nu X) is made.Comment: 7 pages, 2 figures, LaTeX, version with minor changes as accepted by Phys. Rev. Let

    Recommendations of the GARIN group for dietary managing of patient with chronic kidney disease

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    [ES] Introducción y objetivos: en el tratamiento dietético de los pacientes con enfermedad renal crónica (ERC) existen muchas áreas de incertidumbre. El grupo de trabajo GARIN tiene como objetivo defi nir su posición en este campo. Material y métodos: revisión bibliográfi ca previa y reunión presencial en la que se discutieron y contestaron preguntas específi cas sobre el tema. Resultados: la actuación terapéutica debe ser individualizada y atendiendo al grado de enfermedad renal que presente el paciente y a sus comorbilidades. En cuanto a la terapia médica nutricional, nuestro grupo propone tres niveles diferentes de actuación, en los que las recomendaciones de ingesta proteica, fi bra, ácidos grasos o potasio son distintas. Además, sugerimos utilizar el concepto ratio fósforo/proteína en el ajuste de la dieta del paciente con ERC. Damos recomendaciones en cuanto al tratamiento en diabetes y en suplementación artifi cial. Conclusiones: estas recomendaciones aportan respuestas concretas sobre cuestiones comunes en la asistencia a pacientes con ERC.[EN] Background and objectives: by means of this update, the GARIN working group aims to defi ne its position regarding the dietary treatment of patients with chronic kidney disease (CKD). In this area there are many aspects of uncertainty. Material and methods: bibliographical review and specifi c questions in advance were discussed and answered at a meeting in the form of conclusions. Results: the therapeutic action must be individualized and taking into account the degree of renal failure that the patient presents and their comorbidities. Regarding nutritional medical therapy, our group proposes three different levels of action, in which the recommendations of protein intake, fi ber, fatty acids or potassium are different. In addition, we suggest using the phosphorus/protein ratio concept in adjusting the diet of the patient with CKD. We give recommendations regarding treatment in diabetes and artifi cial supplementation. Conclusions: these recommendations about dietary issues in patients with CKD can add value to clinical work.Nestlé Health Nutrition cubrió todos los gastos de transporte y de alquiler de salones para las sesiones físicas, pero no ha tomado parte en el desarrollo, diseño o manuscrito del artículo
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