708 research outputs found
Thermal Boundary Conductance Across Metal-Nonmetal Interfaces: Effects of Electron-Phonon Coupling both in Metal and at Interface
We theoretically investigate the thermal boundary conductance across
metal-nonmetal interfaces in the presence of the electron-phonon coupling not
only in metal but also at interface. The thermal energy can be transferred from
metal to nonmetal via three channels: (1) the phonon-phonon coupling at
interface; (2) the electron-phonon coupling at interface; and (3) the
electron-phonon coupling within metal and then subsequently the phonon-phonon
coupling at interface. We find that these three channels can be described by an
equivalent series-parallel thermal resistor network, based on which we derive
out the analytic expression of the thermal boundary conductance. We then
exemplify different contributions from each channel to the thermal boundary
conductance in three typical interfaces: Pb-diamond, Ti-diamond, and TiN-MgO.
Our results reveal that the competition among above channels determines the
thermal boundary conductance.Comment: 17 pages, 2 figure
Glycyrrhizin could reduce ocular hypertension induced by triamcinolone acetonide in rabbits
Purpose: To evaluate the hypotensive effects of glycyrrhizin (GL) on a rabbit model of ocular hypertension (OH) induced by triamcinolone acetonide (TA). Methods: Forty New Zealand White Rabbits were divided as follows: control (intravitreal injection of sterile saline solution); GL (intravitreal injection of sterile saline solution, then fed with 25mg GL/day); TA (intravitreal TA injection); TA+GL (intravitreal TA injection, then fed with GL) and GL+TA (pre-treated with GL for 3 days, then got TA injection and the following GL treatment). Intraocular pressure (IOP), flash electroretinogram (flash ERG) and flash visual evoked potential (flash VEP) were measured during the follow-up (28 days). The aqueous humor was analyzed, using (1)H-nuclear magnetic resonance spectroscopy and principal components analysis (PCA). Results: IOP elevation was observed in the TA group during the follow-up, compared to the controls (p<0.01). The IOP was decreased in the TA+GL group and the GL+TA group, compared to the TA group (p<0.05). Both in flash ERG and VEP, the amplitudes were decreased, and the implicit time was prolonged in the TA group, compared to the controls (p<0.05); and the parameters were improved after intervention of GL, compared to the TA group (p<0.05). PCA results indicated that TA could affect ocular metabolism (especially the sugar metabolism), and GL could inhibit it. Conclusions: The administration of GL could suppress OH induced by TA in rabbits, and improve their electrophysiological parameters. Metabolomics is a useful tool in ophthalmology research. Our results indicate that TA-induced ocular metabolism changes could be compensated by GL.Biochemistry & Molecular BiologyOphthalmologySCI(E)6ARTICLE2242056-20641
Theory and experiments on driving stability of tank trucks under dangerous working conditions
To study the factors affecting the driving stability of tank trucks under dangerous working conditions, a full vehicle dynamics model and an equivalent test bench for liquid sloshing were designed. On the test bench, two dangerous working conditions were simulated to study liquid sloshing, i.e. braking and turning. The results show that the liquid sloshing force have a major impact on driving stability and the forces depended on the tank geometry, the fill level and the natural sloshing frequency of the liquid. The results of this study still provide a theoretical and experimental basis for studying further the factors that affect the driving stability of tank trucks
Pan-genome analysis of Streptococcus suis serotype 2 highlights genes associated with virulence and antibiotic resistance
Streptococcus suis serotype 2 (SS2) is a Gram-positive bacterium. It is a common and significant pathogen in pigs and a common cause of zoonotic meningitis in humans. It can lead to sepsis, endocarditis, arthritis, and pneumonia. If not diagnosed and treated promptly, it has a high mortality rate. The pan-genome of SS2 is open, and with an increasing number of genes, the core genome and accessory genome may exhibit more pronounced differences. Due to the diversity of SS2, the genes related to its virulence and resistance are still unclear. In this study, a strain of SS2 was isolated from a pig farm in Sichuan Province, China, and subjected to whole-genome sequencing and characterization. Subsequently, we conducted a Pan-Genome-Wide Association Study (Pan-GWAS) on 230 strains of SS2. Our analysis indicates that the core genome is composed of 1,458 genes related to the basic life processes of the bacterium. The accessory genome, consisting of 4,337 genes, is highly variable and a major contributor to the genetic diversity of SS2. Furthermore, we identified important virulence and resistance genes in SS2 through pan-GWAS. The virulence genes of SS2 are mainly associated with bacterial adhesion. In addition, resistance genes in the core genome may confer natural resistance of SS2 to fluoroquinolone and glycopeptide antibiotics. This study lays the foundation for further research on the virulence and resistance of SS2, providing potential new drug and vaccine targets against SS2
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