59 research outputs found
Experimental study on sinomenine derivative modulating chemokine receptor in multiple myeloma cells
Background and purpose: The interaction of CXC motif chemokine receptor (CXCR) on the cell surface of multiple myeloma (MM) with chemokines in the bone marrow microenvironment is involved in proliferation, survival and extramedullary invasion of MM cells. Sinomenine derivative YL064 exerts its biological effects by targeting intracellular signaling regulators in MM cells. This study aimed to explore possible modulating and biological effects of sinomenine derivative YL064 on CXCR3 in MM cells. Methods: The MM cell lines H929 and MM1.S were used as in vitro models. H929-OE and MM1.S-OE cells with stable overexpression of CXCR3 were constructed with lentivirus vector. The effects of CXCR3 on clonal formation and migration of MM cells were detected by clone spot formation and transwell migration assay. Meanwhile, flow cytometry was used to analyze apoptotic rates of H929, H929-OE, MM1.S and MM1.S-OE cells treated with different concentrations of YL064. Furthermore, real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR) and Western blot assay were applied to detect expression levels of CXCR3 and its downstream signal regulators extracellular regulated protein kinase (ERK) and p-protein kinase B (p-AKT) in H929 and MM1.S cells before and after the treatment with YL064. Results: The clonal formation rates of H929-OE and MM1.S-OE cells with CXCR3 overexpression reached to 81.33%±5.79% and 73.00%±4.90%, which were significantly higher compared with H929 (58.33%±3.30%) and MM1.S cells (41.00%±3.14%). The migration proportion of H929-OE and MM1.S-OE cells were 7.90%±0.81% and 23.00%±1.63%, which were significantly higher compared with H929 (4.63%±0.37%) and MM1.S cells (14.63%±1.04%). After treatment with YL064, the apoptotic rates of H929-OE and MM1.S-OE cells were 29.80%±0.30% and 14.20%±0.26%, which were lower than those of H929 (33.40%±0.25%) and MM1.S cells (21.60%±0.21%). It was also shown that YL064 could reduce clonal formation and migration, inhibit CXCR3 gene transcription and downregulate expressions of CXCR3, ERK and AKT in H929 and MM1.S cells. Conclusions: CXCR3 might promote proliferation and invasion of MM cells. Sinomenine derivative YL064 could downregulate expressions of CXCR3 and its downstream signal regulators in MM cells, reduce abilities of clonal formation and migration, and induce apoptosis
Measurements of the observed cross sections for exclusive light hadron production in e^+e^- annihilation at \sqrt{s}= 3.773 and 3.650 GeV
By analyzing the data sets of 17.3 pb taken at GeV
and 6.5 pb taken at GeV with the BESII detector at the
BEPC collider, we have measured the observed cross sections for 12 exclusive
light hadron final states produced in annihilation at the two energy
points. We have also set the upper limits on the observed cross sections and
the branching fractions for decay to these final states at 90%
C.L.Comment: 8 pages, 5 figur
Measurements of psi(2S) decays to octet baryon-antibaryon pairs
With a sample of 14 million psi(2S) events collected by the BESII detector at
the Beijing Electron Positron Collider (BEPC), the decay channels psi(2S)->p
p-bar, Lambda Lambda-bar, Sigma0 Sigma0-bar, Xi Xi-bar are measured, and their
branching ratios are determined to be (3.36+-0.09+-0.24)*10E-4,
(3.39+-0.20+-0.32)*10E-4, (2.35+-0.36+-0.32)*10E-4, (3.03+-0.40+-0.32)*10E-4,
respectively. In the decay psi(2S)->p p-bar, the angular distribution parameter
alpha is determined to be 0.82+-0.17+-0.04.Comment: 8 pages, 8 figure
Adsorption and activation of molecular oxygen over atomic copper(I/II) site on ceria
Supported atomic metal sites have discrete molecular orbitals. Precise control over the energies of these sites is key to achieving novel reaction pathways with superior selectivity. Here, we achieve selective oxygen (O2) activation by utilising a framework of cerium (Ce) cations to reduce the energy of 3d orbitals of isolated copper (Cu) sites. Operando X-ray absorption spectroscopy, electron paramagnetic resonance and density-functional theory simulations are used to demonstrate that a [Cu(I)O2]3− site selectively adsorbs molecular O2, forming a rarely reported electrophilic η2-O2 species at 298 K. Assisted by neighbouring Ce(III) cations, η2-O2 is finally reduced to two O2−, that create two Cu–O–Ce oxo-bridges at 453 K. The isolated Cu(I)/(II) sites are ten times more active in CO oxidation than CuO clusters, showing a turnover frequency of 0.028 ± 0.003 s−1 at 373 K and 0.01 bar PCO. The unique electronic structure of [Cu(I)O2]3− site suggests its potential in selective oxidation
Measurement of \chi_cJ--> K+K-K+K-
Using 14M psi(2S) events taken with the BES-II detector, chi_cJ-->K+K-K+K-
decays are studied. For the four-kaon final state, the branching fractions are
B(chi_c0,1,2 -->K+K-K+K-)=(3.48\pm 0.23\pm 0.47)\times 10^{-3}, (0.70\pm
0.13\pm 0.10)\times 10^{-3}, and (2.17\pm 0.20\pm 0.31)\times 10^{-3}. For the
\phi K+K- final state, the branching fractions, which are measured for the
first time, are B(chi_c0,1,2-->\phi K+K-)=(1.03\pm 0.22\pm 0.15)\times 10^{-3},
(0.46\pm 0.16\pm 0.06)\times 10^{-3}, and (1.67\pm 0.26\pm 0.24)\times 10^{-4}.
For the \phi\phi final state, B(chi_{c0,2}-->\phi\phi)=(0.94\pm 0.21\pm
0.13)\times 10^{-3} and (1.70\pm 0.30\pm 0.25)\times 10^{-3}.Comment: 7 pages, 7 figure
First observation of J/\psi and \psi(2S) decaying to n K^0_S\bar\Lambda +c.c
The decays of \jpsi and \psip to are
observed and measured for the first time, and the perturbative QCD ``12%'' rule
is tested, based on \jpsi and \psip
events collected with BESII detector at the Beijing Electron-Positron Collider.
No obvious enhancement near threshold in \jpsi \to
{n}{K^0_S}\bar{\Lambda}+c.c. is observed, and the upper limit on the branching
ratio of \jpsi \to {K^0_S} X, X \to n \bar \Lambda is determined.Comment: 10 pages, 10 figure
Precison Measurements of the Mass, the Widths of Resonance and the Cross Section at GeV
By analyzing the values measured at 68 energy points in the energy region
between 3.650 and 3.872 GeV reported in our previous paper, we have precisely
measured the mass, the total width, the leptonic width and the leptonic decay
branching fraction of the to be MeV, MeV,
eV and , respectively, which result in
the observed cross section nb at MeV. We have also measured for the continuum light hadron production in the
region from 3.650 to 3.872 GeV.Comment: 5 pages, 2 figure
Study of J\psi decaying into \omega p \bar p
The decay is studied using a
event sample accumulated with the BES II detector at the Beijing
electron-positron collider. The decay branching fraction is measured to be
. No
significant enhancement near the mass threshold is observed, and an
upper limit of is determined at the 95% confidence level, where X(1860)
designates the near-threshold enhancement seen in the mass spectrum
in decays.Comment: 5 pages, 4 figure
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