1,443 research outputs found
Properties of the scalar mesons , and
In the three-state mixing framework, considering the possible glueball
components of and , we investigate the hadronic decays of
, and into two pseudoscalar mesons. The
quarkonia-glueball content of the three states is determined from the fit to
the new data presented by the WA102 Collaboration. We find that these data are
insensitive to the possible glueball components of and .
Furthermore, we discuss some properties of the mass matrix describing the
mixing of the isoscalar scalar mesons.Comment: Latex 14 pages including 1 eps figur
A proposal on the search for the hybrid with in the process at upgraded BEPC/BES
The moment expressions for the boson resonances X with spin-parity 0++, 1-+,
1++, and 2++ possibly produced in the process , , are given in terms of the generalized moment
analysis method. The 1-+ resonance can be distinguished from other resonances
by means of these moments except for some rather special cases. The suggestion
that the search for the 1-+ hybrid can be performed in the above decay channel
at upgraded BEPC/BES is presented.Comment: Latex 13 pages, no figur
Effects of Flavor-dependent Annihilation on the Mixing Angle of the Isoscalar Octet-Singlet and Schwinger's Nonet Mass Formula
By incorporating the flavor-dependent quark-antiquark annihilation amplitude
into the mass-squared matrix describing the mixing of the isoscalar states of a
meson nonet, the new version of Schwinger's nonet mass formula which holds with
a high accuracy for the , , , and
nonets is derived and the mixing angle of isoscalar octet-singlet for these
nonets is obtained. In particular, the mixing angle of isoscalar octet-singlet
for pseudoscalar nonet is determined to take the value of , which
is in agreement with the value of deduced from a
rather exhaustive and up-to-date analysis of data. It is also pointed out that
the omission of the flavor-dependent annihilation effect might be a
factor resulting in the invalidity of Schwinger's original nonet mass formula
for pseudoscalar nonet.Comment: Latex, 7 page
On the mass relation of a meson nonet
It is pointed out that the omission of the effects of the transition between
quarkonia or the assumption that the transition between quarkonia is
flavor-independent would result in the inconsistent results for the
pseudoscalar meson nonet. It is emphasized that the mass relation of the
non-ideal mixing meson nonets should incorporate the effects of the
flavor-dependent transition between quarkonia. The new mass relations of a
meson nonet are presented.Comment: Latex, 10 pages, to appear in Mod. Phys. Lett.
Proteomics study of changes in soybean lines resistant and sensitive to Phytophthora sojae
<p>Abstract</p> <p>Background</p> <p><it>Phytophthora sojae </it>causes soybean root and stem rot, resulting in an annual loss of 1-2 billion US dollars in soybean production worldwide. A proteomic technique was used to determine the effects on soybean hypocotyls of infection with <it>P. sojae</it>.</p> <p>Results</p> <p>In the present study, 46 differentially expressed proteins were identified in soybean hypocotyls infected with <it>P. sojae</it>, using two-dimensional electrophoresis and matrix-assisted laser desorption/ionization tandem time of flight (MALDI-TOF/TOF). The expression levels of 26 proteins were significantly affected at various time points in the tolerant soybean line, Yudou25, (12 up-regulated and 14 down-regulated). In contrast, in the sensitive soybean line, NG6255, only 20 proteins were significantly affected (11 up-regulated and 9 down-regulated). Among these proteins, 26% were related to energy regulation, 15% to protein destination and storage, 11% to defense against disease, 11% to metabolism, 9% to protein synthesis, 4% to secondary metabolism, and 24% were of unknown function.</p> <p>Conclusion</p> <p>Our study provides important information on the use of proteomic methods for studying protein regulation during plant-oomycete interactions.</p
Light absorption properties of brown carbon over the southeastern Tibetan Plateau
We present a study of the light-absorbing properties of water-soluble brown carbon (WS-BrC) and methanolsoluble brown carbon (MeS-BrC) at a remote site (Lulang, 3326 m above sea level) in the southeastern Tibetan Plateau during the period 2015-2016. The light absorption coefficients at 365 nm (b(abs365)) of WS-BrC and MeS-BrC were the highest during winter and the lowest during monsoon season. MeS-BrC absorbs about 1.5 times higher at 365 nm compared to WS-BrC. The absorption at 550 nm appears lower compared to that of 365 nm for WS-BrC and MeS-BrC, respectively. Higher average value of the absorption Angstrom exponent (AAE, 365-550 nm) was obtained for MeS-BrC (8.2) than that for WS-BrC (6.9). The values of the mass absorption cross section at 365 nm (MAC(365)) indicated that BrC in winter absorbs UV-visible light more efficiently than in monsoon. The results confirm the importance of BrC in contributing to light-absorbing aerosols in this region. The understanding of the light absorption properties of BrC is of great importance, especially in modeling studies for the climate effects and transport of BrC in the Tibetan Plateau. (c) 2017 Elsevier B.V. All rights reserved
miR-15a and miR-16-1 inhibit the proliferation of leukemic cells by down-regulating WT1 protein level
<p>Abstract</p> <p>Background</p> <p>miR-15a and miR-16-1(miR-15a/16-1) have been implicated as tumor suppressors in chronic lymphocytic leukemia, multiple myeloma, and acute myeloid leukemic cells. However the mechanism of inhibiting the proliferation of leukemic cells is poorly understood.</p> <p>Methods</p> <p>K562 and HL-60 cells were transfected with pRS-15/16 or pRS-E, cell growth were measured by CCK-8 assay and direct cell count. Meanwhile WT1 protein and mRNA level were measured by Western blotting and quantitative real-time PCR.</p> <p>Results</p> <p>In this study we found that over-expression of miR-15a/16-1 significantly inhibited K562 and HL-60 cells proliferation. Enforced expression of miR-15a/16-1 in K562 and HL-60 cells significantly reduced the protein level of WT1 but not affected the mRNA level. However enforced expression of miR-15a/16-1 can not reduce the activity of a luciferase reporter carrying the 3'-untranslated region(3'UTR) of WT1. Silencing of WT1 by specific siRNA suppressed leukemic cells proliferation resembling that of miR-15a/16-1 over-expression. Anti-miR-15a/16-1 oligonucleotides (AMO) reversed the expression of WT1 in K562 and HL-60 cells. Finally, we found a significant inverse correlation between miR-15a or miR-16-1 expression and WT1 protein levels in primary acute myeloid leukemia (AML) blasts and normal controls.</p> <p>Conclusions</p> <p>These data suggest that miR-15a/16-1 may function as a tumor suppressor to regulate leukemic cell proliferation potentially by down-regulating the WT1 oncogene. However WT1 is not directly targeted by miR-15a/16-1 through miRNA-mRNA base pairing, therefore more study are required to understand the mechanism by which miR-15a/16-1 downregulate WT1.</p
Modification of Kawai model about the mixing of the pseudoscalar mesons
The Kawai model describing the glueball-quarkonia mixing is modified. The
mixing of , and is re-investigated based on
the modified Kawai model. The glueball-quarkonia content of the three states is
determined from a fit to the data of the electromagnetic decays involving
, . Some predictions about the electromagnetic decays
involving are presented.Comment: revtex 8 page
cyclo-Tetrakis{μ-2,2′-dimethyl-1,1′-[2,2-bis(bromomethyl)propane-1,3-diyl]di(1H-benzimidazole)-κ2 N 3:N 3′}tetrakis[bromidocopper(I)]
The title compound, [Cu4Br4(C21H22Br2N4)4], features a macrocyclic Cu4
L
4 ring system in which each CuI atom is coordinated by one bromide ion and two N atoms from two 2,2′-dimethyl-1,1′-[2,2-bis(bromomethyl)propane-1,3-diyl]di(1H-benzimidazole) (L) ligands in a distorted trigonal–planar geometry. The L ligands adopt either a cis or trans configuration. The asymmetric unit contains one half-molecule with the center of the macrocycle located on a crystallographic center of inversion. Each bromide ion binds to a CuI atom in a terminal mode and is oriented outside the ring. The macrocycles are interconnected into a two-dimensional network by π–π interactions between benzimidazole groups from different rings [centroid–centroid distance = 3.803 (5) Å
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