408 research outputs found
Global well-posedness for 2D inviscid and resistive MHD system near an equilibrium
We study the global existence of classical solutions for two-dimensional
incompressible MHD system with only magnetic diffusion. By using the
time-weighted lower-order energy and uniformly bounded higher-order energy
estimates, we prove the global existence result under the assumption that the
initial magnetic field is close enough to a constant magnetic vorticity
equilibrium.Comment: 20 pages. arXiv admin note: text overlap with arXiv:2310.1091
Global solutions of 2D non-resistive MHD system with constant background magnetic vorticity
This paper investigates the stabilization effect of a background magnetic
vorticity on electrically conducting fluids. By exploring the dissipation
nature of the linearized equations, we prove the global existence of smooth
solutions to the two-dimensional incompressible viscous and non-resistive MHD
system.Comment: 21 page
The Functional Investigation of Forkhead Factor FOXQ1 In Human Breast and Colon Cancers'
Ph.DDOCTOR OF PHILOSOPH
Biodegradation and Biotransformation of Indole: Advances and Perspectives
Indole is long regarded as a typical N-heterocyclic aromatic pollutant in industrial and agricultural wastewater, and recently it has been identified as a versatile signaling molecule with wide environmental distributions. An exponentially growing number of researches have been reported on indole due to its significant roles in bacterial physiology, pathogenesis, animal behavior and human diseases. From the viewpoint of both environmental bioremediation and biological studies, the researches on metabolism and fates of indole are important to realize environmental treatment and illuminate its biological function. Indole can be produced from tryptophan by tryptophanase in many bacterial species. Meanwhile, various bacterial strains have obtained the ability to transform and degrade indole. The characteristics and pathways for indole degradation have been investigated for a century, and the functional genes for indole aerobic degradation have also been uncovered recently. Interestingly, many oxygenases have proven to be able to oxidize indole to indigo, and this historic and motivating case for biological applications has attracted intensive attention for decades. Herein, the bacteria, enzymes and pathways for indole production, biodegradation and biotransformation are systematically summarized, and the future researches on indole-microbe interactions are also prospected
An Adaptive Spatial-Temporal Local Feature Difference Method for Infrared Small-moving Target Detection
Detecting small moving targets accurately in infrared (IR) image sequences is
a significant challenge. To address this problem, we propose a novel method
called spatial-temporal local feature difference (STLFD) with adaptive
background suppression (ABS). Our approach utilizes filters in the spatial and
temporal domains and performs pixel-level ABS on the output to enhance the
contrast between the target and the background. The proposed method comprises
three steps. First, we obtain three temporal frame images based on the current
frame image and extract two feature maps using the designed spatial domain and
temporal domain filters. Next, we fuse the information of the spatial domain
and temporal domain to produce the spatial-temporal feature maps and suppress
noise using our pixel-level ABS module. Finally, we obtain the segmented binary
map by applying a threshold. Our experimental results demonstrate that the
proposed method outperforms existing state-of-the-art methods for infrared
small-moving target detection
Corrosion Behavior of Alloy C-276 in Supercritical Water
The corrosion behavior of Alloy C-276 in high-temperature and high-pressure water at 500Ā°C and 25āMPa, respectively, was investigated by means of mass gain, scanning electron microscopic observation, and X-ray diffraction. The results indicated that the mass gain rate of Alloy C-276 in supercritical water obeys the parabolic law. The oxide scale was formed on Alloy C-276 with a dual-layer structure, mainly consisting of an outer Ni-rich layer and an inner Cr2O3/NiCr2O4 mixed layer. Tiny microcracks can also be found in the oxide scale if exposed for longer time. Meanwhile, higher temperature promotes oxide rate and results in thermal stress in the oxide film
GATA binding protein 2 mediates leptin inhibition of PPARĪ³1 expression in hepatic stellate cells and contributes to hepatic stellate cell activation
AbstractHepatic stellate cell (HSC) activation is a crucial step in the development of liver fibrosis. Peroxisome-proliferator activated receptor Ī³ (PPARĪ³) exerts a key role in the inhibition of HSC activation. Leptin reduces PPARĪ³ expression in HSCs and plays a unique role in promoting liver fibrosis. The present studies aimed to investigate the mechanisms underlying leptin regulation of PPARĪ³1 (a major subtype of PPARĪ³) in HSCs in vivo and in vitro. Results revealed a leptin response region in mouse PPARĪ³1 promoter and indicated that the region included a GATA binding protein binding site around position ā2323. GATA binding protein-2 (GATA-2) could bind to the site and inhibit PPARĪ³1 promoter activity in HSCs. Leptin induced GATA-2 expression in HSCs in vitro and in vivo. GATA-2 mediated leptin inhibition of PPARĪ³1 expression by its binding site in PPARĪ³1 promoter in HSCs and GATA-2 promoted HSC activation. Leptin upregulated GATA-2 expression through Ī²-catenin and sonic hedgehog pathways in HSCs. Leptin-induced increase in GATA-2 was accompanied by the decrease in PPARĪ³ expression in HSCs and by the increase in the activated HSC number and liver fibrosis in vivo. Our data might suggest a possible new explanation for the promotion effect of leptin on liver fibrogenesis
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