386 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
Effects of Brain-Derived Neurotrophic Factor on Local Inflammation in Experimental Stroke of Rat
This study was aimed to investigate whether brain-derived neurotrophic factor (BDNF) can modulate local cerebral inflammation in ischemic stroke. Rats were subjected to ischemia by occluding the right middle cerebral artery (MCAO) for 2 hours. Rats were randomized as control, BDNF, and antibody groups. The local inflammation was evaluated on cellular, cytokine, and transcription factor levels with immunofluorescence, enzyme-linked immunosorbent assay, real-time qPCR, and electrophoretic mobility shift assay, respectively. Exogenous BDNF significantly improved motor-sensory, sensorimotor function, and vestibulomotor function, while BDNF did not decrease the infarct volume. Exogenous BDNF increased the number of both activated and phagocytotic microglia in brain. BDNF upregulated interleukin10 and its mRNA expression, while downregulated tumor necrosis factor α and its mRNA expression. BDNF also increased DNA-binding activity of nuclear factor-kappa B. BDNF antibody, which blocked the activity of endogenous BDNF, showed the opposite effect of exogenous BDNF. Our data indicated that BDNF may modulate local inflammation in ischemic brain tissues on the cellular, cytokine, and transcription factor levels
Treatment of Nutrient-rich Municipal Wastewater Using Mixotrophic Strain Chlorella kessleri GXLB-9
Growing algae on wastewaters offers a promising way for effective N and P recycling as well as low-cost algal biofuel feedstock accumulation. In this study, a locally isolated microalgae strain Chlorella kessleri GXLB-9 (C. kessleri GXLB-9), was evaluated for growth and nutrient removal efficiency grown in nutrient-rich wastewater centrifuged from activated sludge (NWCAS). And 3-(3, 4-dichlorophenyl)-1, 1-dimethyl urea (DCMU), one chemical that could block microalgae-based photosynthetic pathway, was used to evaluate the growth mode (autotrophy, heterotrophy or mixotrophy) of C. kessleri GXLB-9. The results showed that C. kessleri GXLB-9 was a facultative heterotrophic strain and 7-day batch cultivation idicated that the maximal removal efficiencies for total nitrogen, total phosphorus, and chemical oxygen demand (COD) were over 59%, 81%, and 88%, respectively, with high growth rate (0.490 d-1) and high biomass productivity (269 mg L-1 d-1). In addition, the impact of light-dark cycle on algae growth and nutrient removal was minimal while pH has significant impact on both algae growth and nutrient removal efficiency
Nuclear Respiratory Factor 1 Negatively Regulates the P1 Promoter of the Peroxisome Proliferator-Activated Receptor-γ Gene and Inhibits Chicken Adipogenesis
Peroxisome proliferator-activated receptor-γ (PPARγ) is a master regulator of adipogenesis, and alterations in its function are associated with various pathological processes related to metabolic syndrome. Recently, we found that the chicken PPARγ gene is regulated by three alternative promoters (P1, P2 and P3), producing five different transcript isoforms and two protein isoforms. In this study, the P1 promoter structure was characterized. Bioinformatics identified six putative nuclear respiratory factor 1 (NRF1) binding sites in the P1 promoter, and a reporter assay showed that NRF1 inhibited the activity of the P1 promoter. Of the six putative NRF1 binding sites, individual mutations of three of them abolished the inhibitory effect of NRF1 on P1 promoter activity. Furthermore, a ChIP assay indicated that NRF1 directly bound to the P1 promoter, and real-time quantitative RT-PCR analysis showed that NRF1 mRNA expression was negatively correlated with PPARγ1 expression (Pearson’s r = -0.148, p = 0.033). Further study showed that NRF1 overexpression inhibited the differentiation of the immortalized chicken preadipocyte cell line (ICP1), which was accompanied by reduced PPARγ1 mRNA expression. Taken together, our findings indicated that NRF1 directly negatively regulates the P1 promoter of the chicken PPARγ gene and inhibits adipogenesis
Quantitative Detection and Uncertainty Analysis of Low-level Presence of Genetically Modified Ingredient in Soybean
In this study, the low-level presence of genetically modified (GM) soybean event GTS-40-3-2 was quantitatively detected and the measurement uncertainty was estimated. Within 95% confidence interval, the quantitative method developed using real-time polymerase chain reaction (PCR) and digital PCR could stably detect 0.01% GTS-40-3-2 content with acceptable cost and uncomplicated operation, while the digital PCR method could quantify 0.1% GTS-40-3-2 content accurately, and the quantitative error did not exceed 50% even at GTS-40-3-2 content as low as 0.05%. The sources of uncertainty in quantitative digital PCR analysis were analyzed, and the calculation formula for uncertainty was derived from calculation models in analytical chemistry. Furthermore, GTS-40-3-2 was used for laboratory verification. The expanded uncertainty in quantitative analysis of 0.1% and 0.05% GTS-40-3-2 contents was calculated as 23.56% and 107.29% (k = 2), respectively
Cytosolic and Nucleosolic Calcium Signaling in Response to Osmotic and Salt Stresses Are Independent of Each Other in Roots of Arabidopsis Seedlings
Calcium acts as a universal second messenger in both developmental processes and responses to environmental stresses. Previous research has shown that a number of stimuli can induce [Ca2+] increases in both the cytoplasm and nucleus in plants. However, the relationship between cytosolic and nucleosolic calcium signaling remains obscure. Here, we generated transgenic plants containing a fusion protein, comprising rat parvalbumin (PV) with either a nuclear export sequence (PV-NES) or a nuclear localization sequence (NLS-PV), to selectively buffer the cytosolic or nucleosolic calcium. Firstly, we found that the osmotic stress-induced cytosolic [Ca2+] increase (OICIcyt) and the salt stress-induced cytosolic [Ca2+] increase (SICIcyt) were impaired in the PV-NES lines compared with the Arabidopsis wildtype (WT). Similarly, the osmotic stress-induced nucleosolic [Ca2+] increase (OICInuc) and salt stress-induced nucleosolic [Ca2+] increase (SICInuc) were also disrupted in the NLS-PV lines. These results indicate that PV can effectively buffer the increase of [Ca2+] in response to various stimuli in Arabidopsis. However, the OICIcyt and SICIcyt in the NLS-PV plants were similar to those in the WT, and the OICInuc and SICInuc in the PV-NES plants were also same as those in the WT, suggesting that the cytosolic and nucleosolic calcium dynamics are mutually independent. Furthermore, we found that osmotic stress- and salt stress-inhibited root growth was reduced dramatically in the PV-NES and NLS-PV lines, while the osmotic stress-induced increase of the lateral root primordia was higher in the PV-NES plants than either the WT or NLS-PV plants. In addition, several stress-responsive genes, namely CML37, DREB2A, MYB2, RD29A, and RD29B, displayed diverse expression patterns in response to osmotic and salt stress in the PV-NES and NLS-PV lines when compared with the WT. Together, these results imply that the cytosolic and nucleosolic calcium signaling coexist to play the pivotal roles in the growth and development of plants and their responses to environment stresses
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