3,200 research outputs found
Electromagnetic proton-neutron knockout off 16O: new achievements in theory
Results for the cross sections of the exclusive 16O(e,e'pn)14N and
16O(gamma,pn)14N knockout reactions are presented and discussed in different
kinematics. In comparison with earlier work, a complete treatment of the
center-of-mass (CM) effects in the nuclear one-body current is considered in
connection with the problem of the lack of orthogonality between initial bound
and final scattering states. The effects due to CM and orthogonalization are
investigated in combination with different treatments of correlations in the
two-nucleon overlap function and for different parametrizations of the two-body
currents. The CM effects lead in super-parallel kinematics to a dramatic
increase of the 16O(e,e'pn) cross section to the 1_2^+ excited state (3.95 MeV)
of 14N. In all the situations considered the results are very sensitive to the
treatment of correlations. A crucial role is played by tensor correlations, but
also the contribution of long-range correlations is important.Comment: 13 pages, 10 figure
On the NN-final-state-interaction in the reaction
The influence of the mutual interaction between the two outgoing nucleons
(NN-FSI) in the reaction has been investigated.
Results for various kinematics are discussed. In general, the effect of
NN-FSI depends on kinematics and the chosen final state in the excitation
spectrum of .Comment: 12 pages Revtex including 4 postscript figure
On the treatment of the -contribution in electromagnetic -knockout reactions
The treatment of the -current and its contribution in the exclusive
OC and OC knockout reactions are
investigated in combination with the effects of correlations.
Different parametrizations of the effective -current and different
treatments of correlations in the two-nucleon overlap function are considered.
The results are presented and discussed for a suitable choice of kinematics. It
is found that the investigation of different mutually supplementing kinematics
is necessary to resolve the uncertainties in the theoretical ingredients and
extract clear and unambiguous information on correlations.Comment: 15 pages, 9 figures, EPJA styl
The NN-final-state-interaction in two-nucleon-knockout reactions
The influence of the mutual interaction between the two outgoing nucleons
(NN-FSI) in electro- and photoinduced two-nucleon knockout from has
been investigated perturbatively. It turns out that the effect of NN-FSI
depends on the kinematics and on the type of reaction considered. In the
kinematics studied so far, the effect is larger in pp- than in pn-knockout and
in electron induced than in photoinduced reactions.Comment: 10 pages including 9 postscript figures, contribution to the 6th
workshop on "Electromagnetically Induced Two-Hadron Emission", Pavia,
September 24-27, 200
One- and Two-Nucleon Structure form Green's Function Theory
We review some applications of self-consistent Green's function theory to
studies of one- and two-nucleon structure in finite nuclei.
Large-scale microscopic calculations that employ realistic nuclear forces are
now possible. Effects of long-range correlations are seen to play a dominant
role in determining the quenching of absolute spectroscopic factors. They also
enhance considerably (e,e'pn) cross sections in superparallel kinematics, in
agreement with observations.Comment: Proceedings of the International Symposium on "Forefronts of
Researches in Exotic Nuclear Structures" (Niigata2010)
A co-ultramicronized palmitoylethanolamide/luteolin composite mitigates clinical score and disease-relevant molecular markers in a mouse model of experimental autoimmune encephalomyelitis
Background: Persistent and/or recurrent inflammatory processes are the main factor leading to multiple sclerosis (MS) lesions. The composite ultramicronized palmitoylethanolamide, an endogenous N-acylethanolamine, combined with the flavonoid luteolin, PEALut, have been found to exert neuroprotective activities in experimental models of spinal and brain injury and Alzheimer disease, as well as a clinical improvement in human stroke patients. Furthermore, PEALut enhances the expression of different myelin proteins in oligodendrocyte progenitor cells suggesting that this composite might have protective effects in MS experimental models. Methods: The mouse model of experimental autoimmune encephalomyelitis (EAE) based on active immunization with a fragment of myelin oligodendrocyte glycoprotein (MOG35-55) was used. The daily assessment of clinical score and the expression of serum amyloid A (SAA1), proinflammatory cytokines TNF-\u3b1, IL-1\u3b2, IFN-\u3b3, and NLRP3 inflammasome, as well as TLR2, Fpr2, CD137, CD3-\u3b3, and TCR-\u3b6 chain, heterodimers that form T cell surface glycoprotein (TCR), and cannabinoid receptors CB1, CB2, and MBP, were evaluated in the brainstem and cerebellum at different postimmunization days (PIDs). Results: Vehicle-MOG35-55-immunized (MOG35-55) mice developed ascending paralysis which peaked several days later and persisted until the end of the experiment. PEALut, given intraperitoneally daily starting on day 11 post-immunization, dose-dependently improved clinical score over the range 0.1-5 mg/kg. The mRNA expression of SAA1, TNF-\u3b1, IL-1\u3b2, IFN-\u3b3, and NLRP3 were significantly increased in MOG35-55 mice at 14 PID. In MOG35-55 mice treated with 5 mg /kg PEALut, the increase of SAA1, TNF- \u3b1, IL-1\u3b2, and IFN-\u3b3transcripts at 14 PID was statistically downregulated as compared to vehicle-MOG35-55 mice (p < 0.05). The expression of TLR2, Fpr2, CD137, CD3-\u3b3, TCR-\u3b6 chain, and CB2 receptors showed a significant upregulation in vehicle-MOG35-55 mice at 14 PID. Instead, CB1 and MBP transcripts have not changed in expression at any time. In MOG/PEALut-treated mice, TLR2, Fpr2, CD137, CD3-\u3b3, TCR-\u3b6 chain, and CB2 mRNAs were significantly downregulated as compared to vehicle MOG35-55 mice. Conclusions: The present results demonstrate that the intraperitoneal administration of the composite PEALut significantly reduces the development of clinical signs in the MOG35-55 model of EAE. The dose-dependent improvement of clinical score induced by PEALut was associated with a reduction in transcript expression of the acute-phase protein SAA1, TNF-\u3b1, IL-1\u3b2, IFN-\u3b3, and NLRP3 proinflammatory proteins and TLR2, Fpr2, CD137, CD3-\u3b3, TCR-\u3b6 chain, and CB2 receptors
Short-range and tensor correlations in the O(e,epn) reaction
The cross sections for electron induced two-nucleon knockout reactions are
evaluated for the example of the O(e,epn)N reaction leading to
discrete states in the residual nucleus N. These calculations account
for the effects of nucleon-nucleon correlations and include the contributions
of two-body meson exchange currents as the pion seagull, pion in flight and the
isobar current contribution. The effects of short-range as well as tensor
correlations are calculated within the framework of the coupled cluster method
employing the Argonne V14 potential as a model for a realistic nucleon-nucleon
interaction. The relative importance of correlation effects as compared to the
contribution of the meson exchange currents depends on the final state of the
residual nucleus. The cross section leading to specific states, like e.g. the
ground state of N, is rather sensitive to the details of the correlated
wave function.Comment: 16 pages, 9 figures include
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