98 research outputs found
CFD Analysis and optimization of the DEMO WCLL central outboard segment bottom-Cap elementary cell
In the design of magnetic confinement nuclear fusion power plants, the Breeding Blanket (BB) plays a crucial
role, since it must fulfil key functions such as tritium breeding, radiation-shielding and removing of the heat
power generated by the plasma. The latter task is achieved by the First Wall (FW) and Breeding Zone (BZ)
cooling systems, that in the Water-Cooled Lithium-Lead (WCLL) BB employs pressurized water. Different
arrangements of BZ coolant conduits have been investigated in the recent past to identify an efficient layout,
which could meet the structural materials operational temperature constraint and that could provide the optimal
coolant outlet temperature. However, most of the Computational Fluid-Dynamic (CFD) analysis carried out
until now have been focused on the equatorial WCLL elementary cell of the Central Outboard Segment (COB).
The aim of this work is to broaden the analysis to other relevant locations in the blanket. An assessment of the
design of the cooling system of the COB bottom-cap elementary BZ cell has been identified as the top design
priority due to its different geometry and thermal loads. The cooling efficiency of the BZ and FW systems is
investigated to assess if the coolant appropriate design conditions are matched and the temperature distribution
in the cell is analyzed to identify the onset of hot spots. Different layouts of the FW systems are proposed and
compared in terms of thermal-hydraulics reliability
The prokineticin receptor agonist Bv8 decreases IL-10 and IL-4 production in mice splenocytes by activating prokineticin receptor-1
<p>Abstract</p> <p>Background</p> <p>Bv8, prokineticin-1, or endocrine gland-vascular endothelial growth factor, and prokineticin-2 are recently isolated peptide agonists of two G protein-coupled receptors, prokineticin receptor-1 (PROKR 1) and PROKR 2, and have been described as affecting a number of myeloid cell functions. We evaluated the impact of Bv8 on lymphoid cells by investigating its ability to modulate T cell cytokine balance in mouse.</p> <p>Results</p> <p>The production of T-helper1 cytokines (IL-2, IFN-γ and IL-1β), the T-helper 2 cytokine IL-4, and the anti-inflammatory cytokine IL-10 by mouse splenocytes was evaluated after polyclonal stimulation or immunisation with the keyhole limpet hemocyanin protein antigen by measuring cytokine levels. When added <it>in vitro </it>to Con-A-stimulated splenocytes, Bv8 significantly increased IL-1β and decreased IL-4 and IL-10; IL-2 and IFN-γ were not affected. Similar results were obtained when Bv8 was administered <it>in vivo</it>. In KLH-immunised mice, splenocytes restimulated <it>in vitro </it>with KLH and Bv8 produced significantly smaller amounts of IL-4 and IL-10. KLH-induced IL-10 and IL-4 production was also significantly blunted in animals administered Bv8 <it>in vivo </it>at the time of KLH immunisation or two weeks later. The Bv8-induced effects were lost in mice lacking the PROKR 1 gene, thus indicating that PROKR 1 is the receptor involved in the modulation of cytokines.</p> <p>Conclusion</p> <p>These findings indicate that Bv8/prokineticin-1 is a novel modulator of lymphoid functions, and may be a suitable target for new immunopharmacological strategies.</p
Computational modeling of immune system of the fish for a more effective vaccination in aquaculture
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Probing Dark Energy with Supernovae : Bias from the time evolution of the equation of state
Observation of thousands of type Ia supernovae should offer the most direct
approach to probe the dark energy content of the universe. This will be
undertaken by future large ground-based surveys followed by a space mission
(SNAP/JDEM). We address the problem of extracting the cosmological parameters
from the future data in a model independent approach, with minimal assumptions
on the prior knowledge of some parameters. We concentrate on the comparison
between a fiducial model and the fitting function and adress in particular the
effect of neglecting (or not) the time evolution of the equation of state. We
present a quantitative analysis of the bias which can be introduced by the
fitting procedure. Such bias cannot be ignored as soon as the statistical
errors from present data are drastically improved.Comment: 22 pages, 10 figures, submitted to Phys. Rev.
Unified Model for Dark Energy
A new model for the universe filled with a generalized Chaplygin fluid is
considered which unitarily describes as a single vacuum entity both a
quintessence scalar field and a cosmological constant, so unifying the notion
of dark energy. While the evolution of the universe filled with such a fluid
does not obviously contradict the present cosmic acceleration, the introduced
single dark-energy component, for equations of state with characteristic
parameter , behaves like an usual quintessence fluid with
constant equation of state at early high densities, and like a pure
cosmological constant at late cosmological times.Comment: 5 pages, some misprints corrected, a comment on the initial equation
of state inserted, one reference adde
The dermorphin peptide family
1. In 1980, the skin of certain frogs belonging to the genus Phyllomedusinae was found to contain two new peptides that proved to be selective mu-opioid agonists. Given the name dermorphins, these were the first members of a peptide family that in the past 15 years has grown to reach a total of seven naturally occurring peptides and nearly 30 synthetic analogs. 2. Dermorphin peptides are potent analgesics in rodents and primates, including man. Some dermorphins can enter the blood-brain barrier and produce central antinociception after peripheral administration. 3. The dermorphin family also includes mu(1)-opioid receptor selective agonists that produce intense opioid analgesia, but stimulate pulmonary ventilation. 4. Experiments in rats and mice chronically exposed to dermorphins have shown that not only do they have higher antinociceptive efficacy and potency than morphine, but they are also less likely than morphine to produce tolerance, dependence and opiate side effects. Copyright (C) 1996 Elsevier Science Inc
Nonmammalian tachykinins: their contribution to the discovery and biological characterization of the mammalian neurokinin system
Action of sauvagine on the mesenteric vascular bed of the dog.
Sauvagine, a linear peptide of 40 amino acids, produced hypotension when administered intravenously to anesthetized dogs. Diastolic pressure was always more affected than systolic pressure. Aortic blood flow and venous return both increased to the same extent. The mechanism of the hypotensive response was mainly, if not exclusively, due to dilatation of the superior and inferior mesenteric arteries. Intravenous infusion of sauvagine in doses ranging from 3 to 10 ng . kg-1 . min-1 produced a dose-related increase of mesenteric blood flow up to 400% control values. Mucosal-submucosal blood flow of ileum and colon was increased, while blood flow in muscle was unaffected or slight decreased. The mesenteric vasodilator response was not prevented by adrenergic or muscarinic receptor blockade. The hypotensive response was more marked and sustained in dibenamine-propranolol treated dogs
Interaction of deltorphin analogs with delta and mu-opioid activity on rat locomotor behavior
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