4,772 research outputs found
Role of quark-interchange processes in evolution of mesonic matter
We divide the cross section for a meson-meson reaction into three parts. The
first part is for the quark-interchange process, the second for quark-antiquark
annihilation processes and the third for resonant processes. Master rate
equations are established to yield time dependence of fugacities of pions,
rhos, kaons and vetor kaons. The equations include cross sections for inelastic
scattering of pions, rhos, kaons and vector kaons. Cross sections for
quark-interchange-induced reactions, that were obtained in a potential model,
are parametrized for convenient use. The number densities of pion and rho (kaon
and vector kaon) are altered by quark-interchange processes in equal magnitudes
but opposite signs. The master rate equations combined with the hydrodynamic
equations for longitudinal and transverse expansion are solved with many sets
of initial meson fugacities. Quark-interchange processes are shown to be
important in the contribution of the inelastic meson-meson scattering to
evolution of mesonic matter.Comment: 28 pages, 1 figure, 8 table
Icariin induces autophagy and apoptosis of chondrocytes by inhibiting NF-κB signaling pathway
Purpose: To investigate the effect of icariin on autophagy and apoptosis of chondrocytes, and the associated mechanisms.Methods: The chondrocytes were randomly divided into control (PBS intervention), TNF-α intervention, icarin +TNF-α, and NF-κB inhibition +TNF-α, with 8 strains in each group. The levels of IL-1, IL-6 and IL-12 were assayed by ELISA. The mRNA and protein expressions of ATG5, ATG7, Bax and Bcl-2 cells were determined by polymerase chain reaction (PCR) and Western blotting, while protein expressions of p-p65 and IκBα were assayed using Western blotting.Results: In the cartilage tissue of rats in the icariin +TNF-α group and NF-κB inhibition +TNF-α group, IL-1, IL-6 and IL-12 levels were significantly lower than those in TNF-α treatment group (p < 0.05). The AATG5 mRNA and protein in cartilage tissues of rats in icariin +TNF-α and NF-κB inhibition +TNF-α groups were significantly higher than those in TNF-α group. Bax mRNA and protein in cartilage tissues of icariin +TNF-α and NF-κB inhibition +TNF-α groups were downregulated, relative to TNF-α group; on the other hand, Bcl-2 mRNA and protein were significantly higher than those of TNF-α group (p < 0.05). In the cartilage tissues of Icarin +TNF-α, NF-κB inhibition +TNF-α groups, P-p65 protein was significantly lower than that of TNF-α (p < 0.05).Conclusion: TNF-α enhances the production of a large number of inflammatory factors by cartilage cells, inhibits autophagy of cartilage cells, and promotes cell apoptosis through regulation of NF-κB signaling pathway.
Keywords: Icariin, NF-κB signaling pathway, TNF-α, Inflammatory response, Chondrocytes, Autophagy, Apoptosi
Calibration of a superconducting transformer by measuring critical current of a NbTi Rutherford cable
Large high field superconducting magnets often requires high current
superconducting cables. In order to develop these cables, a facility capable of
providing high magnetic field with large sampling area as well as electrical
current of tens of kA is essential. A superconducting transformer is an
energy-efficient and low-cost way to provide large current to superconducting
cables. Previously, we co-developed a superconducting transformer and
successfully tested it to a maximum output current of 45 kA in zero magnetic
field. In this work, this superconducting transformer is installed to the 12 T
split solenoid magnet at the National High Magnetic Field Laboratory (NHMFL).
We calibrated it by using this facility to measure critical current of a NbTi
Rutherford cable as a function of magnetic field up to 10 T, and compare the
results with those available in the literature. In addition, a strand extracted
from the NbTi cable is tested for critical current. The critical current of the
extracted strand is scaled and compared with critical current of the cable. The
accuracy of the critical current measurement using this superconducting
transformer is discussed in detail. This work concludes the commissioning of
this superconducting transformer which combined with the 12 T split magnet will
provide unique cable testing capability for future cable development for the
NHMFL and its users.Comment: 11 pages, 9 figure
On the structure of the -fold sumsets
Let~ be a set of nonnegative integers. Let~ be the set of all
integers in the sumset~ that have at least~ representations as a sum
of~ elements of~. In this paper, we prove that, if~,
and~ is a finite set of integers
such that~ and then there exist integers ~ and
sets~, such that for all~ This
improves a recent result of Nathanson with the bound .Comment: 8 page
Page Curve and Phase Transition in deformed Jackiw-Teitelboim Gravity
We consider the entanglement island in a deformed Jackiw-Teitelboim black
hole in the presence of the phase transition. This black hole has the van der
Waals-Maxwell-like phase structure as it is coupled with a Maxwell field. We
study the behavior of the Page curve of this black hole by using the island
paradigm. In the fixed charge ensemble, we discuss different situations with
different charges that influence the system's phase structure. There is only a
Hawking-Page phase transition in the absence of charges, which leads to an
unstable small black hole. Hence, the related Page curve does not exist.
However, a van der Waals-Maxwell-like phase transition occurs in the presence
of charges. This yields three black hole solutions. The Page curve of the
middle size black hole does not exist. For the extremal black hole, the Page
time approaches zero in the phase transition situation but becomes divergent
without the phase transition. In a word, we study the Page curve and the island
paradigm for different black hole phases and in different phase transition
situations.Comment: 28 pages, 13 figures, references added, published versio
Increased electrical conductivity in fine-grained (Zr,Hf)NiSn based thermoelectric materials with nanoscale precipitates
Grain refinement has been conducted to reduce the thermal conductivity and improve the thermoelectric performance of the (Zr,Hf)NiSn based half-Heusler alloys. Nanoscale in situ
precipitates were found embedded in the matrix with submicron grains. The lattice thermal conductivity was decreased due to the enhanced boundary scattering of phonons. The increased carrier concentration and electrical conductivity were observed compared to the coarse-grained
alloys, which is discussed in relation to the existence of nanoscale precipitates, the effect of antisite defects, and composition change. It is suggested that the nanoscale precipitates play a significant role in the observed electrical conductivity increase
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