14 research outputs found

    Characterization of a Li-6 loaded liquid organic scintillator for fast neutron spectrometry and thermal neutron detection

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    The characterization of a liquid scintillator incorporating an aqueous solution of enriched lithium chloride to produce a scintillator with 0.40% Li-6 is presented, including the performance of the scintillator in terms of its optical properties and neutron response. The scintillator was incorporated into a fast neutron spectrometer, and the light output spectra from 2.5 MeV, 14.1 MeV, and Cf-252 neutrons were measured using capture-gated coincidence techniques. The spectrometer was operated without coincidence to perform thermal neutron measurements. Possible improvements in spectrometer performance are discussed.Comment: Submitted to Applied Radiation and Isotopes. 11 pages, 7 figures, 3 tables. Revision addresses reviewers' comment

    Threshold Electrodisintegration of ^3He

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    Cross sections were measured for the near-threshold electrodisintegration of ^3He at momentum transfer values of q=2.4, 4.4, and 4.7 fm^{-1}. From these and prior measurements the transverse and longitudinal response functions R_T and R_L were deduced. Comparisons are made against previously published and new non-relativistic A=3 calculations using the best available NN potentials. In general, for q<2 fm^{-1} these calculations accurately predict the threshold electrodisintegration of ^3He. Agreement at increasing q demands consideration of two-body terms, but discrepancies still appear at the highest momentum transfers probed, perhaps due to the neglect of relativistic dynamics, or to the underestimation of high-momentum wave-function components.Comment: 9 pages, 7 figures, 1 table, REVTEX4, submitted to Physical Review

    A high precision n-p scattering measurement at 14.9 MeV

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    The n-p scattering angular distribution was measured with 14.9 MeV incident neutrons using the traditional time-of-flight technique with neutron-gamma discrimination. The scattering angle varied from 20o to 65o (laboratory system) in 5o incremental steps. The efficiency of the neutron detectors was measured in the energy range 2–9 MeV relative to the 252Cf-standard, and was calculated using Monte Carlo methods in the 2–14 MeV energy range. Two methods of analysis were applied for experimental and simulated data: a traditional approach with a fixed threshold, and a dynamic threshold approach. The present data agree with the ENDF/B-VII evaluation for the shape of n-p angular distribution within about 1.5%

    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

    A high precision n-p scattering measurement at 14.9 MeV

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    The n-p scattering angular distribution was measured with 14.9 MeV incident neutrons using the traditional time-of-flight technique with neutron-gamma discrimination. The scattering angle varied from 20o to 65o (laboratory system) in 5o incremental steps. The efficiency of the neutron detectors was measured in the energy range 2–9 MeV relative to the 252Cf-standard, and was calculated using Monte Carlo methods in the 2–14 MeV energy range. Two methods of analysis were applied for experimental and simulated data: a traditional approach with a fixed threshold, and a dynamic threshold approach. The present data agree with the ENDF/B-VII evaluation for the shape of n-p angular distribution within about 1.5%

    Linseed essential oil - source of lipids as active ingredients for pharmaceuticals and nutraceuticals

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    Linseed - also known as flaxseed - is known for its beneficial effects on animal health attributed to its composition. Linseed comprises linoleic and ?-linolenic fatty acids, various dietary fibers and lignans, which are beneficial to health because they reduce the risk of cardiovascular diseases, as well as cancer, decreasing the levels of cholesterol and relaxing the smooth muscle cells in arteries increasing the blood flow. Essential fatty acids from flax participate in several metabolic processes of the cell, not only as structuring components of the cell membrane but also as storage lipids. Flax, being considered a functional food, can be consumed in a variety of ways, including seeds, oil or flour, contributing to basic nutrition. Several formulations containing flax are available on the market in the form of e.g. capsules and microencapsulated powders having potential as nutraceuticals. This paper revises the different lipid classes found in flaxseeds and their genomics. It also discusses the beneficial effects of flax and flaxseed oil and their biological advantages as ingredients in pharmaceuticals and in nutraceuticals products.The authors wish to acknowledge the financial support from the Portuguese Science and Technology Foundation, Ministry of Science and Education (FCT/MEC) through national funds, and co-financed by FEDER, under the Partnership Agreement PT2020 for the project M-ERA-NET/0004/2015-PAIRED.info:eu-repo/semantics/publishedVersio
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