4,036 research outputs found
Light-Cone Sum Rules Analysis of Weak Decays
In this work, we investigate the semi-leptonic weak decays of spin-1/2
doubly-heavy baryons into spin-3/2 singly-heavy baryons
within light-cone sum rules. Using the parallel
components of the light-cone distribution amplitudes of
, the transition form factors for these decays are
calculated both analytically and numerically. The numerical results for these
semi-leptonic weak decays widths and branching ratios are also predicted, which
are compared with the same predictions by other theoretical approaches in the
literatures. These phenomenology predictions can be tested by the experiments
in the future.Comment: 19 pages, 2 figures, 4 table
A new hybrid Dawson-type molybdenum arsenate derivative: (H2bpy)3[As2Mo18O62] (bpy = 4,4′-bipyridine)
The title compound, tris(4,4′-bipyridinium) diarsenooctadecamolybdate(VI), (C10H10N2)3[As2Mo18O62], featuring protonated bipyridine molecules and a classical Dawson-type polyoxo-anion, has been synthesized under hydrothermal conditions. The polyoxoanions are linked together via the bipyridyl cations, acting as hydrogen-bond donors, generating a two-dimensional supramolecular network. The asymmetric unit contains 1.5 4,4′-bipyridinium (H2bpy) units, with an inversion centre in the central bond of the second H2bpy unit. The site symmetry of the anion is
Effect of PPARγ agonist (rosiglitazone) on the secretion of Th2 cytokine in asthma mice
AbstractObjectiveTo explore the effect of PPARγ agonist (rosiglitazone) on the secretion of Th2 cytokines and the proportion of immune cell subsets in asthma mice.MethodsOvalbumin (OVA)-sensitized mice were used to build asthma models. Those mice were divided into the normal control group, model group and rosiglitazone group. Differences of the changes in lung histopathology of mice in the three groups were observed through hematoxylin and eosin (HE) strain, and the numbers of the total cells, eosinophils and neutrophils in BALF of mice in the three groups were compared. ELISA and real-time PCR were employed to detect the protein levels of interleukin (IL)-5, IL-13, IL-4 and IL-10 and mRNA level, respectively. Flow cytometry number was implied to analyze the proportion of immune cell subsets in peripheral blood of mice.ResultsCompared with the mice in the control group, and mice of the model group, the infiltration of inflammatory cells in BALF increased, bronchial smooth muscle became thickened, a large amount of collagen deposited, the secretion of Th2 cytokine increased significantly, the ratio of regulatory T cells (Treg) decreased, the ratio of T17 cells rose distinctly; while in mice of the rosiglitazone group, the changes of their lung histopathology were improved obviously, the number of infiltration of inflammatory cells declined, the thickened smooth muscle relieved, the deposition of collagen decreased, the secretion of Th2 cytokine was inhibited, the ratio of Treg went up, and the increased of the ratio of T17 cells was inhibited but still not return to normal level.ConclusionsRosiglitazone can regulate the proportion of Treg and Th17 cells and inhibit the secretion of Th2 cytokines, which inhibit the airway inflammatory response for asthma mice effectively
Poly[tetrakis(2,2′-bipyridine)undeca-μ-oxido-hexaoxidodicopper(II)hexavanadium(V)]
In the title organic–inorganic hybrid vanadate complex, [Cu2V6O17(C10H8N2)4]n, the CuII atom is six-coordinated by two chelating 2,2′-bipyridine (bipy) ligands and two vanadate O atoms in a distorted octahedral geometry. Two [Cu(bipy)2V3O8] units are linked by a bridging O atom, which lies on an inversion center, forming a dimeric unit. The dimeric units are further connected by bridging vanadate O atoms into a two-dimensional layer parallel to (100). The layers are connected by weak C—H⋯O hydrogen bonds
Tris(piperazinediium) phosphatododecamolybo(V,VI)phosphate
The title compound, (C4H12N2)3[PMo12O40] or (H2pip)3[PMo12O40] (pip is piperazine), was prepared under hydrothermal conditions. The asymmetric unit contains one-sixth of a mixed-valent Mo(V,VI) pseudo-Keggin-type [PMo12O40]6− anion and half a piperazinediium cation, (H2pip)2+. The discrete Keggin-type [PMo12O40]6- anion has site symmetry and the three (H2pip)2+ cations each have site symmetry at the centres of the molecules. The central P atom is on special position , which is a roto-inversion position and generates the disorder of the PO4 tetrahedron. Furthermore, six doubly bridging oxide groups are also disordered with an occupancy factor of 0.5 for each O atom. The anions and cations are linked by an extensive network of intermolecular N—H⋯O and C—H⋯O hydrogen bonds
Baryons in the light-front approach: the three-quark picture
In this work, a three-quark picture is constructed using a bottom-up approach
for baryons in light-front quark model. The shape parameters, which
characterize the momentum distribution inside a baryon, are determined with the
help of the pole residue of the baryon. The relation between the three-quark
picture and the diquark picture is clarified. In model construction, we find
that Lorentz boost effect plays an important role, and the bottom-up modeling
approach can be generalized to multiquark states. Based on this, a unified
theoretical framework for describing multiquark states may be established. As a
by-product of model construction, we can easily obtain a new and possibly
better definition of baryon interpolating current. The hadron interpolating
currents are the starting point of Lattice QCD and QCD sum rules, and therefore
have important significance.Comment: 17 page
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