872 research outputs found
Analysis of the vertices , and with light-cone QCD sum rules
In this article, we calculate the strong coupling constants of the ,
and in the framework of the light-cone QCD sum
rules approach. The strong coupling constants of the meson-baryon-baryon are
the fundamental parameters in the one-boson exchange model which describes the
baryon-baryon interactions successfully. The numerical values are in agreement
with the existing calculations in part. The electric and magnetic
ratios deviate from the prediction of the vector meson dominance theory, the
SU(3) symmetry breaking effects are very large.Comment: 19 pages, 6 figures, revised version, add more discussions(Correct
writing errors
Tumor necrosis factor–Α contributes to below-level neuropathic pain after spinal cord injury
Objective Our objective was to elucidate the mechanisms responsible for below-level pain after partial spinal cord injury (SCI). Methods We used lateral hemisection to model central neuropathic pain and herpes simplex viral (HSV) vector–mediated transfer of the cleaved soluble receptor for tumor necrosis factor–Α (TNF-Α) to evaluate the role of TNF-Α in the pathogenesis of below-level pain. Results We found activation of microglia and increased expression of TNF-Α below the level of the lesion in the lumbar spinal cord after T13 lateral hemisection that correlated with emergence of mechanical allodynia in the hind limbs of rats. Lumbar TNF-Α had an apparent molecular weight of 27kDa, consistent with the full-length transmembrane form of the protein (mTNF-Α). Expression of the p55 TNF soluble receptor (sTNFRs) by HSV-mediated gene transfer resulted in reduced pain behavior and a decreased number of ED1-positive cells, as well as decreased phosphorylation of the p38 MAP kinase (p-p38) and diminished expression of mTNF-Α in the dorsal horn. Interpretation These results suggest that expression of mTNF-Α after injury is related to development of pain, and that reverse signaling through mTNF-Α by sTNFR at that level reduces cellular markers of inflammatory response and pain-related behavior. Ann Neurol 2006;59:843–851Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50655/1/20855_ftp.pd
Analysis of the as a baryonium state with Bethe-Salpeter equation
In this article, we take the X(1835) as a pseudoscalar baryonium state, and
calculate the mass spectrum of the baryon-antibaryon bound states ,
, , and in the
framework of the Bethe-Salpeter equation with a phenomenological potential. The
numerical results indicate the , and
bound states maybe exist, and the can be tentatively
identified as the bound state.Comment: 7 pages, 1 figure, published versio
Radiative decays of the strange-bottom mesons
In this article, we assume that the strange-bottom mesons are the
conventional mesons, and calculate the electromagnetic coupling
constants , , and using the light-cone QCD sum rules. Then
we study the radiative decays , ,
and , and observe that the
widths are rather narrow. We can search for the strange-bottom
mesons in the invariant and mass distributions in the
strong decays or in the invariant and mass
distributions in the radiative decays.Comment: 16 pages, 4 figures, revised versio
Evolutionary prisoner's dilemma game with dynamic preferential selection
We study a modified prisoner's dilemma game taking place on two-dimensional
disordered square lattices. The players are pure strategists and can either
cooperate or defect with their immediate neighbors. In the generations each
player update its strategy by following one of the neighboring strategies with
a probability dependent on the payoff difference. The neighbor selection obeys
a dynamic preferential rule, i.e., the more frequently a neighbor's strategy
was adopted by the focal player in the previous rounds, the larger probability
it will be chosen to refer to in the subsequent rounds. It is found that
cooperation is substantially promoted due to this simple selection mechanism.
Corresponding analysis is provided by the investigations of the distribution of
players' impact weights, persistence, and as well as correlation function.Comment: 7 pages, 5 figure
Transitions To the Long-Resident State in coupled chaotic oscillators
The behaviors of coupled chaotic oscillators before complete synchronization
were investigated. We report three phenomena: (1) The emergence of long-time
residence of trajectories besides one of the saddle foci; (2) The tendency that
orbits of the two oscillators get close becomes faster with increasing the
coupling strength; (3) The diffusion of two oscillator's phase difference is
first enhanced and then suppressed. There are exact correspondences among these
phenomena. The mechanism of these correspondences is explored. These phenomena
uncover the route to synchronization of coupled chaotic oscillators.Comment: 3 pages, 5 figure
Developments of a 2D Position Sensitive Neutron Detector
Chinese Spallation Neutron Source (CSNS), one project of the 12th
five-year-plan scheme of China, is under construction in Guangdong province.
Three neutron spectrometers will be installed at the first phase of the
project, where two-dimensional position sensitive thermal neutron detectors are
required. Before the construction of the neutron detector, a prototype of
two-dimensional 200 mmx200 mm Multi-wire Proportional Chamber (MWPC) with the
flowing gas of Ar/CO2 (90/10) has been constructed and tested with the 55Fe
X-Ray using part of the electronics in 2009, which showed a good performance.
Following the test in 2009, the neutron detector has been constructed with the
complete electronics and filled with the 6atm.3He + 2.5atm.C3H8 gas mixture in
2010. The neutron detector has been primarily tested with an Am/Be source. In
this paper, some new developments of the neutron detector including the design
of the high pressure chamber, the optimization of the gas purifying system and
the gas filling process will be reported. The results and discussion are also
presented in this paper.Comment: 5 page
A study of the inclusion complex formed between cucurbit[8]uril and isonicotinic acid
The complexation between cucurbit[8]uril, Q[8], and isonicotinic acid has been studied using 1H NMR spectroscopy, UV–Vis absorption spectroscopy, Raman spectroscopy and single crystal X-ray diffraction. The results revealed that the 2:1 inclusion complex (4-PA)2@Q[8]·25H2O is formed, with two guests simultaneously encapsulated in the hydrophobic cavity; the mean planes of the guests are 3.535 Å apart. Graphical abstract: [Figure not available: see fulltext.
Reanalysis of the (0^+,1^+) states B_{s0} and B_{s1} with QCD sum rules
In this article, we calculate the masses and decay constants of the -wave
strange-bottomed mesons and with the QCD sum rules, and
observe that the central values of the masses of the and are
smaller than the corresponding and thresholds respectively, the
strong decays and are kinematically forbidden.
They can decay through the isospin violation precesses and . The bottomed mesons
and , just like their charmed cousins and
, maybe very narrow.Comment: 9 pages, 5 figures, 4-versio
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