674 research outputs found
A systematic study on the binding energy of hypernuclei
In this paper, we calculated the binding energy per baryon of the
hypernuclei systemically, using the relativistic mean field theory (RMF) in a
statistic frame. Some resemble properties are found among most of the
hypernuclei found in experiments. The data show that a hypernucleus
will be more stable, if it is composed of a hyperon adding to a
stable normal nuclear core, or a hyperon replacing a neutron in a
stable normal nuclear core. According to our calculations, existences of some
new hypernuclei are predicted under the frame of RMF.Comment: 8 pages, 6 figures, 3 table
Observation of prolonged coherence time of the collective spin wave of atomic ensemble in a paraffin coated Rb vapor cell
We report a prolonged coherence time of the collective spin wave of a thermal
87Rb atomic ensemble in a paraffin coated cell. The spin wave is prepared
through a stimulated Raman Process. The long coherence time time is achieved by
prolonging the lifetime of the spins with paraffin coating and minimize
dephasing with optimal experimental configuration. The observation of the long
time delayed-stimulated Stokes signal in the writing process suggests the
prolonged lifetime of the prepared spins; a direct measurement of the decay of
anti-Stokes signal in the reading process shows the coherence time is up to 300
us after minimizing dephasing. This is one hundred times longer than the
reported coherence time in the similar experiments in thermal atomic ensembles
based on the Duan-Lukin-Cirac-Zoller (DLCZ) and its improved protocols. This
prolonged coherence time sets the upper limit of the memory time in quantum
repeaters based on such protocols, which is crucial for the realization of
long-distance quantum communication. The previous reported fluorescence
background in the writing process due to collision in a sample cell with buffer
gas is also reduced in a cell without buffer gas.Comment: 4 pages, 4 figure
Construction of Drug Screening Cell Model and Application to New Compounds Interfering Production and Accumulation of Beta-Amyloid by Inhibiting Gamma-Secretase
Radiative transitions in charmonium from twisted mass lattice QCD
We present a study for charmonium radiative transitions:
, and
using twisted mass lattice QCD gauge
configurations. The single-quark vector form factors for and
are also determined. The simulation is performed at a lattice
spacing of fm and the lattice size is . After
extrapolation of lattice data at nonzero to 0, we compare our results
with previous quenched lattice results and the available experimental values.Comment: typeset with revtex, 15 pages, 11 figures, 4 table
The effect of different baryons impurities
We demonstrate the different effect of different baryons impurities on the
static properties of nuclei within the framework of the relativistic mean-field
model. Systematic calculations show that and has the
same attracting role as hyperon does in lighter hypernuclei.
and hyperon has the attracting role only for the protons
distribution, and has a repulsive role for the neutrons distribution. On the
contrary, and hyperon attracts surrounding neutrons and
reveals a repulsive force to the protons. We find that the different effect of
different baryons impurities on the nuclear core is due to the different third
component of their isospin.Comment: 9 page
CD147 overexpression on synoviocytes in rheumatoid arthritis enhances matrix metalloproteinase production and invasiveness of synoviocytes
Macrophage-like synoviocytes and fibroblast-like synoviocytes (FLS) are known as the most active cells of rheumatoid arthritis (RA) and are close to the articular cartilage in a position enabling them to invade the cartilage. Macrophage-like synoviocytes and FLS expression of matrix metalloproteinases (MMPs) and their interaction has aroused great interest. The present article studied the expression of CD147, also called extracellular matrix metalloproteinase inducer, on monocytes/macrophages and FLS from RA patients and its potential role in enhancing MMPs and the invasiveness of synoviocytes. Expression of CD147 on FLS derived from RA patients and from osteoarthritis patients, and expression of CD147 on monocytes/macrophages from rheumatic synovial fluid and healthy peripheral blood were analyzed by flow cytometry. The levels of CD147, MMP-2 and MMP-9 mRNA in FLS were detected by RT-PCR. The role of CD147 in MMP production and the cells' invasiveness in vitro were studied by the co-culture of FLS with the human THP-1 cell line or monocytes/macrophages, by gel zymography and by invasion assay. The results showed that the expression of CD147 was higher on RA FLS than on osteoarthritis FLS and was higher on monocytes/macrophages from rheumatic synovial fluid than on monocytes/macrophages from healthy peripheral blood. RT-PCR showed that the expressions of CD147, MMP-2 and MMP-9 mRNA was higher in RA FLS than in osteoarthritis FLS. A significantly elevated secretion and activation of MMP-2 and MMP-9 were observed in RA FLS co-cultured with differentiated THP-1 cells or RA synovial monocytes/macrophages, compared with those co-cultured with undifferentiated THP-1 cells or healthy control peripheral blood monocytes. Invasion assays showed an increased number of invading cells in the co-cultured RA FLS with differentiated THP-1 cells or RA synovial monocytes/macrophages. CD147 antagonistic peptide inhibited the MMP production and the invasive potential. Our studies demonstrated that the CD147 overexpression on monocytes/macrophages and FLS in RA patients may be responsible for the enhanced MMP secretion and activation and for the invasiveness of synoviocytes. These findings suggest that CD147 may be one of the important factors in progressive joint destruction of RA and that CD147 may be a potential therapeutic target in RA treatment
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