20 research outputs found
The spectrum of low- in heavy ion collisions in a fractal description
Transverse momentum spectrum of particles in hadron gas are affected by flow,
quantum and strong interaction effects. Previously, most models focus on only
one of the three effects but ignore others. The unconsidered effects are taken
into the fitted parameters. In this paper, we study the three effects together
from a new fractal angle by physical calculation instead of data fitting. Near
the critical temperature, the three effects induce and neighboring
meson to form a two-meson structure. We set up a two-particle fractal (TPF)
model to describe this structure. We propose that under the three effects,
- two-meson state, and two-quark states form a
self-similarity structure. With evolution, the two-meson structure
disintegrate. We introduce an influencing factor to describe the
flow, quantum and strong interaction effects and an escort factor to
describe the binding force and the three effects. By solving the probability
and entropy equations, we obtain the values of and at different
collision energies and centrality classes. By substituting the value of
into distribution function, we obtain the transverse momentum
spectrum of low- and find it in good agreement with experimental
data. We also analyze the evolution of with the temperature. It is
found that is larger than 1. This is because the three effects
decrease the number of microstates. We also find decreases with
decreasing the temperature. This is consistent with the fact that with the
system expansion, the influence of the three effects decrease.Comment: 9 pages, 3 figure
Regulation of Autophagy of Prostate Cancer Cells by β-Catenin Signaling
Background/Aims: Autophagy is a cellular degradation process for the recycling of damaged or superfluous intracellular compartments to provide an alternative energy source during periods of metabolic stress for maintaining cell homeostasis and viability. Although autophagy in different contexts have been shown to use similar signaling pathways, the exact molecular regulation of autophagy has been found to be cell-type dependent. Methods: We used rapamycin to trigger autophagy and used nitric oxide (NO) to inhibit autophagy in prostate cancer cells. IWP-2 was used to inhibit β-catenin signaling. Autophagy-associated proteins were examined by Western blot. Results: We found that nitric oxide (NO), a potent cellular messenger, impaired rapamycin-induced autophagy in prostate cancer cells. Further analyses showed that NO induced nuclear accumulation of β-catenin, a key factor of Wnt signaling pathway, to inhibit autophagy in prostate cancer cells. Conclusions: We demonstrate involvement of β-catenin signaling in the regulation of autophagy of prostate cancer cells. Our results shed light on a previously unappreciated β-catenin signaling pathway for regulating autophagy in prostate cancer
Spatio-Temporal Error Sources Analysis and Accuracy Improvement in Landsat 8 Image Ground Displacement Measurements
Because of the advantages of low cost, large coverage and short revisit cycle, Landsat 8 images have been widely applied to monitor earth surface movements. However, there are few systematic studies considering the error source characteristics or the improvement of the deformation field accuracy obtained by Landsat 8 image. In this study, we utilize the 2013 Mw 7.7 Balochistan, Pakistan earthquake to analyze error spatio-temporal characteristics and elaborate how to mitigate error sources in the deformation field extracted from multi-temporal Landsat 8 images. We found that the stripe artifacts and the topographic shadowing artifacts are two major error components in the deformation field, which currently lack overall understanding and an effective mitigation strategy. For the stripe artifacts, we propose a small spatial baseline (<200 m) method to avoid the stripe artifacts effect on the deformation field. We also propose a small radiometric baseline method to reduce the topographic shadowing artifacts and radiometric decorrelation noises. Those performances and accuracy evaluation show that these two methods are effective in improving the precision of deformation field. This study provides the possibility to detect subtle ground movement with higher precision caused by earthquake, melting glaciers, landslides, etc., with Landsat 8 images. It is also a good reference for error source analysis and corrections in deformation field extracted from other optical satellite images
Protocatechuic acid inhibits proliferation, migration and inflammatory response in rheumatoid arthritis fibroblast-like synoviocytes
AbstractRheumatoid arthritis (RA) is a chronic joint inflammatory disease that is closely associated with dysregulation of fibroblast-like synoviocytes (FLSs). Protocatechuic acid (PCA), a phenolic compound of anthocyanins, has been proven to possess anti-inflammatory activity. However, the role of PCA in RA has not been investigated. In the present study, we aimed to explore the effects of PCA on the RA-FLSs. The results showed that PCA suppressed the proliferation, invasion, and migration of RA-FLSs in a dose-dependent manner. PCA treatment also inhibited the expressions of matrix metalloproteinase (MMP)-3 and MMP-13, as well as the secretion of inflammatory cytokines including TNF-α, IL-1β, IL-6 in RA-FLSs. Moreover, cell apoptosis of RA-FLSs was significantly induced by PCA treatment. PCA was found to repress the activation of NF-κB signalling, which was evidenced by the decreased expression of p-p65 and increased expression of IκBα. Furthermore, PCA significantly decreased the phosphorylation levels of Akt and mTOR in RA-FLSs. In conclusion, the results indicated that PCA exhibited an inhibitory effect on RA-FLSs via inhibiting the NF-κB and Akt/mTOR signalling pathways. These findings supported the concept that PCA might be a therapeutic agent for RA treatment
The in-situ synthesis of TiC in Cu melts based on Ti–C–Si system and its mechanism
International audienc
Management and control mode of underground coal mining based on medium and high-level intelligent technology
Coal is the guarantee energy in China, and its dominant position in energy will not change for a period of time in the future. Coal intelligent mining will show a rapid development trend and enter into a new stage of development. Through induction and analysis, the great significance, development law, contradiction, construction method and future development direction of intelligent construction of coal mine are summarized in this paper. This paper systematically expounds the reform process of coal mining technology and management mode in China, and summarizes the five stages of manual mining, ordinary mining, comprehensive mechanized mining, automatic mining, primary intelligent mining, as well as the corresponding technical modes. Breaking through the intelligent research ideas such as traditional coal roadheader mining, this paper puts forward 10 characteristics of medium and high-level intelligent mining technology of coal, namely, complete transparency of coal mine, comprehensive intelligence of perception, high-end intelligence of equipment, real-time reliability of network, integrated platform control, intelligent analysis of data, group collaboration intelligence, professional team employees, dynamic decision-making intelligence, disaster prevention and control matching, and gives the definition, characteristics, content and function of each characteristic. Based on the premise of medium and high-level intelligent technology, the corresponding ‘1+1’ management and control mode of coal mine mining is conceived, that is, one level is set in one coal mine, and a new flat platform management and control mode of ‘one command and control center+one professional team’ is constructed. Therefore, the mode can promote the reform of production mode, match the requirements of corresponding mining mode in the future intelligent rapid development and realize the real meaning of reducing personnel, increasing safety and improving efficiency. Finally, the further development of intelligent mining technology and mode in coal mine is prospected
Seasonal and Spatial Fluctuations of Reactive Oxygen Species in Riparian Soils and Their Contributions on Organic Carbon Mineralization
Reactive oxygen species (ROS) are ubiquitous in the natural
environment
and play a pivotal role in biogeochemical processes. However, the
spatiotemporal distribution and production mechanisms of ROS in riparian
soil remain unknown. Herein, we performed uninterrupted monitoring
to investigate the variation of ROS at different soil sites of the
Weihe River riparian zone throughout the year. Fluorescence imaging
and quantitative analysis clearly showed the production and spatiotemporal
variation of ROS in riparian soils. The concentration of superoxide
(O2•–) was 300% higher in summer
and autumn compared to that in other seasons, while the highest concentrations
of 539.7 and 20.12 μmol kg–1 were observed
in winter for hydrogen peroxide (H2O2) and hydroxyl
radicals (•OH), respectively. Spatially, ROS production
in riparian soils gradually decreased along with the stream. The results
of the structural equation and random forest model indicated that
meteorological conditions and soil physicochemical properties were
primary drivers mediating the seasonal and spatial variations in ROS
production, respectively. The generated •OH significantly
induced the abiotic mineralization of organic carbon, contributing
to 17.5–26.4% of CO2 efflux. The obtained information
highlighted riparian zones as pervasive yet previously underestimated
hotspots for ROS production, which may have non-negligible implications
for carbon turnover and other elemental cycles in riparian soils