2,550 research outputs found
In-Beam Background Suppression Shield
The long (3ms) proton pulse of the European Spallation Source (ESS) gives
rise to unique and potentially high backgrounds for the instrument suite. In
such a source an instrument capabilities will be limited by it's Signal to
Noise (S/N) ratio. The instruments with a direct view of the moderator, which
do not use a bender to help mitigate the fast neutron background, are the most
challenging. For these beam lines we propose the innovative shielding of
placing blocks of material directly into the guide system, which allow a
minimum attenuation of the cold and thermal fluxes relative to the background
suppression. This shielding configuration has been worked into a beam line
model using Geant4. We study particularly the advantages of single crystal
sapphire and silicon blocks .Comment: 12 pages, 8 figures, proceeding of NDS 2015, 4th International
Workshop on Neutron Delivery Systems, 28 -30 September 2015, ILL Grenoble,
Franc
Facility for fast neutron irradiation tests of electronics at the ISIS spallation neutron source
The VESUVIO beam line at the ISIS spallation neutron source was set up for neutron irradiation tests in the neutron energy range above 10 MeV. The neutron flux and energy spectrum were shown, in benchmark activation measurements, to provide a neutron spectrum similar to the ambient one at sea level, but with an enhancement in intensity of a factor of 107. Such conditions are suitable for accelerated testing of electronic components, as was demonstrated here by measurements of soft error rates in recent technology field programable gate arrays
Liquid-liquid phase transition in Stillinger-Weber silicon
It was recently demonstrated that the Stillinger-Weber silicon undergoes a
liquid-liquid first-order phase transition deep into the supercooled region
(Sastry and Angell, Nature Materials 2, 739 (2003)). Here we study the effects
of perturbations on this phase transition. We show that the order of the
liquid-liquid transition changes with negative pressure. We also find that the
liquid-liquid transition disappears when the three-body term of the potential
is strengthened by as little as 5 %. This implies that the details of the
potential could affect strongly the nature and even the existence of the
liquid-liquid phase.Comment: 13 page
The B7 Homologues and their Receptors in Hematologic Malignancies
The B7 homologues and their receptors regulate both peripheral tolerance and adaptive immunity. This field is rapidly evolving as new ligands and receptors are being identified. Much of the work supporting their role in the regulation of host anti‐tumor immunity has been derived from experimental models and clinical trials in solid malignancies. However, a growing body of evidence demonstrates that the B7‐H family has important immunologic and non‐immunologic functions in a variety of hematologic malignancies. Herein, we will review recent evidence that supports the therapeutic targeting of the B7 homologues in hematologic malignancies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91338/1/ejh1766.pd
a telescope proton recoil spectrometer for fast neutron beam lines
A telescope proton recoil spectrometer for fast neutron beam-lines C. Cazzaniga1,3,∗, M. Rebai2,3, M. Tardocchi3, G. Croci2,3, M. Nocente2,3, S. Ansell1, C. D. Frost1, and G. Gorini2,3 1ISIS Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK 2Universita degli Studi di Milano-Bicocca, Dipartimento di Fisica, Piazza della Scienza 3, Milano, Italy 3Istituto di Fisica del Plasma "P. Caldirola", Associazione EURATOM-ENEA/CNR, Via Cozzi 53, Milano, Italy ∗E-mail: [email protected]
Challenges to wellbeing for General Practice trainee doctors: a qualitative study of their experiences and coping strategies.
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Spatial distribution of metabolites in the retina and its relevance to studies of metabolic retinal disorders
Introduction: The primate retina has evolved regional specialisations for specific visual functions. The macula is specialised towards high acuity vision and is an area that contains an increased density of cone photoreceptors and signal processing neurons. Different regions in the retina display unique susceptibility to pathology, with many retinal diseases primarily affecting the macula. Objectives: To better understand the properties of different retinal areas we studied the differential distribution of metabolites across the retina. Methods: We conducted an untargeted metabolomics analysis on full-thickness punches from three different regions (macula, temporal peri-macula and periphery) of healthy primate retina. Results: Nearly half of all metabolites identified showed differential abundance in at least one comparison between the three regions. Furthermore, mapping metabolomics results from macula-specific eye diseases onto our region-specific metabolite distributions revealed differential abundance defining systemic metabolic dysregulations that were region specific. Conclusions: The unique metabolic phenotype of different retinal regions is likely due to the differential distribution of different cell types in these regions reflecting the specific metabolic requirements of each cell type. Our results may help to better understand the pathobiology of retinal diseases with region specificity
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