107 research outputs found
Hom-Big Brackets: Theory and Applications
In this paper, we introduce the notion of hom-big brackets, which is a
generalization of Kosmann-Schwarzbach's big brackets. We show that it gives
rise to a graded hom-Lie algebra. Thus, it is a useful tool to study
hom-structures. In particular, we use it to describe hom-Lie bialgebras and
hom-Nijenhuis operators
Fluoxetine treatment for major depression decreases the plasma levels of cytokines
Elevated levels of pro-inflammatory biomarkers have been reported in major depressive disorder (MDD). The aim of this study is to investigate the plasma levels of interleukin-18 (IL-18), macrophageinflammatory protein-1α (MIP-1α), monocyte chemoattractant protein 1 (MCP-1), stromal cell derived factor-1 (SDF-1), and regulated upon activation, normal T cell expressed and secreted (RANTES) in patients with MDD before and after eight week treatment of fluoxetine hydrochloride in comparison with normal controls. All subjects were assessed before and after treatment with the Hamilton Depression Rating Scale (HDRS). Our results showed that the symptoms of forty healthy controls and thirty-four patients with MDD were correlated with their plasma levels of IL-18, MIP-1α, MCP-1, SDF-1α, and RANTES. The levels of all five cytokine of patients with MDD were significantly decreased after treatment. However, the levels remained significantly higher than those of the healthy controls (p<0.001). In the seven depressed subjects whose HDRS score fell to below seven after antidepressant therapy comparing with those subjects whose HDRS score larger than seven, the mean levels of IL-18 (p=0.01) and SDF-1α(p<0.05) were significantly lower. Conversely, higher levels of cytokines correlated with a persistently increased severity of symptoms, as measured by the HDRS scores. In conclusion, these findings suggest that MDD is associated with activation of the immune system, and the antidepressant effect of fluoxetine may be mediated in part through its anti-inflammatory effects.Key words: Fluoxetine hydrochloride, major depression, cytokine, chemokine, inflammation
Numerical simulation of mechanical compaction and pore evolution of sandstone considering particle breakage
Mechanical compaction is an important diagenetic process in sandstone reservoirs. Particle breakage, which commonly occurs during mechanical compaction, plays a significant role in controlling the physical properties of the reservoir. However, existing numerical simulation methods have limitations in simulating mechanical compaction when considering particle breakage. In this study, a discrete element simulation method of mechanical compaction was proposed based on particle cutting, and the experimental results reported in the literature were used to calibrate the simulation parameters. Finally, this method was applied to the simulation of the mechanical compaction of sandstone to analyze the pore evolution process. The results show that the new simulation method has high computational efficiency and can reflect the process of particle breakage. The simulation results coincide well with the experimental results. In the simulated mechanical compacted process of coarse sandstone, particle breakage is strong in the high-stress stage with a vertical stress of 30 MPa–50 MPa. The porosity and mean radii of pores and throats decreased rapidly, and the number of pores and throats increased rapidly in the high-stress stage. When the vertical stress reached 50 MPa, compared to the simulation results without considering particle breakage, the porosity difference rate caused by particle breakage was 4.63%; the radius difference rates of pores and throats were 2.78% and 6.8%, and the number difference rates of pores and throats were 4.95% and 8.74%, respectively. In the process of mechanical compaction, the pore evolution of the reservoir is controlled by the filling of the pre-existing pore space by the fragments generated through particle breakage and the generation of microfractures. Additionally, the simulation method presented in this study can be applied to complex geological conditions and can be combined with other reservoir simulation methods. The simulation results can provide rich training samples for artificial intelligence and other emerging technologies
Spin-glass ground state in a triangular-lattice compound YbZnGaO
We report on comprehensive results identifying the ground state of a
triangular-lattice structured YbZnGaO to be spin glass, including no
long-range magnetic order, prominent broad excitation continua, and absence of
magnetic thermal conductivity. More crucially, from the ultralow-temperature
a.c. susceptibility measurements, we unambiguously observe frequency-dependent
peaks around 0.1 K, indicating the spin-glass ground state. We suggest this
conclusion to hold also for its sister compound YbMgGaO, which is confirmed
by the observation of spin freezing at low temperatures. We consider disorder
and frustration to be the main driving force for the spin-glass phase.Comment: Version as accepted to PR
Multidimensional difference analysis in gastric cancer patients between high and low latitude
Genetic variation has been shown to affect tumor growth and progression, and the temperature at different latitudes may promote the evolution of genetic variation. Geographical data with latitudinal information is of importance to understand the interplay between genetic variants and environmental influence, such as the temperature, in gastric cancer (GC). In this study, we classified the GC samples from The Cancer Genome Atlas database into two groups based on the latitudinal information of patients and found that GC samples with low-latitude had better clinical outcomes. Further analyses revealed significant differences in other clinical factors such as disease stage and grade between high and low latitudes GC samples. Then, we analyzed the genomic and transcriptomic differences between the two groups. Furthermore, we evaluated the activity score of metabolic pathways and infiltrating immune cells in GC samples with different latitudes using the single-sample gene set enrichment analysis algorithm. These results showed that GC samples at low-latitude had lower tumor mutation burden and subclones as well as higher DNA repair activities. Meanwhile, we found that most immune cells were associated with the prognosis of low-latitude GC patients. At last, we constructed and validated an immune-related prognostic model to evaluate the prognosis of GC samples at different latitudes. This study has provided a further understanding of the geographical contribution to GC at the multiomic level and may benefit the individualized treatment of GC patients at different latitudes
Surface passivation for highly active, selective, stable, and scalable CO2 electroreduction
Electrochemical conversion of CO2 to formic acid using Bismuth catalysts is one the most promising pathways for industrialization. However, it is still difficult to achieve high formic acid production at wide voltage intervals and industrial current densities because the Bi catalysts are often poisoned by oxygenated species. Herein, we report a Bi3S2 nanowire-ascorbic acid hybrid catalyst that simultaneously improves formic acid selectivity, activity, and stability at high applied voltages. Specifically, a more than 95% faraday efficiency was achieved for the formate formation over a wide potential range above 1.0 V and at ampere-level current densities. The observed excellent catalytic performance was attributable to a unique reconstruction mechanism to form more defective sites while the ascorbic acid layer further stabilized the defective sites by trapping the poisoning hydroxyl groups. When used in an all-solid-state reactor system, the newly developed catalyst achieved efficient production of pure formic acid over 120 hours at 50 mA cm–2 (200 mA cell current)
- …