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MicroRNAs (miRs) are key posttranscriptional regulators of gene expression in all eukaryotic cells and have a vital role in the evolution of hypertension and cardiovascular remodelling and, therefore, have emerged as potential biomarkers for cardiovascular disease. We assessed 240 participants, including 60 healthy volunteers with normal carotid intima-media thickness (nCIMT), 60 healthy volunteers with increased CIMT (iCIMT), 60 hypertensive patients with nCIMT and 60 hypertensive patients with iCIMT. All patients underwent measurements of CIMT, carotid-femoral pulse wave velocity (cfPWV) and ambulatory blood pressure (BP) monitoring. Plasma miR-92a expression was quantified by real-time reverse transcription PCR. Correlations between miR-92a expression and BP parameters, CIMT and cfPWV were assessed using the Spearman correlation coefficient. We observed the lowest miR-92a expression (24.59±1.30 vs 27.76±2.13 vs 29.29±1.89 vs 33.76±2.08; P

It is shown that the alkylation of toluene with ethylene to give p-ethyltoluene can be conducted selectively on small crystals (⩽ 1μ) of unmodified H-ZSM-5 zeolites to a level higher than that corresponding to a thermodynamic equilibrium composition. A comparison of the ethyltoluene isomers formed with H-Y and H-ZSM-5 zeolites at various conversions and temperatures indicates that p -ethyltoluene is preferentially formed in the channel intersections of the H-ZSM-5 zeolite, even during the initial alkylation step. The final ethyltoluene isomer composition is a result of competition between the rates of alkylation and isomerization and subsequent diffusional transport of individual isomers through the zeolite channels. Zeolite coking causes an apparent increase in the p -ethyltoluene selectivity; however, a more dramatic decrease in toluene conversion results in the formation of a considerably lower amount of p -ethyltoluene. This is caused by a partial blocking of the zeolite channel system.

For the fatigue failure of 42CrMo, the tensile test was performed on the CT specimen at different load ratios using a fatigue tensile tester. Data on the fatigue crack growth rate of the material and the crack tip factor were obtained. Scanning electron microscopy (SEM) was used to observe the microstructure and crack initiation and propagation of fractures. The crack initiation and propagation path law during fatigue crack propagation were obtained. The fatigue crack life was calculated by Paris formula, and the fatigue crack growth test and microscopic observation were compared. The propagation law and fatigue crack life of different stages of crack propagation were analyzed. The results show that the stable propagation stage of fatigue crack propagation is the key stage to determine fatigue fracture, the rate of growth is related to the stress ratio.

Based on 28 year field data of Stipa bungeana community in arid, semi-arid, semi-humid areas of the Loess Plateau of Northwestern China, we studied species diversity and above ground biomass of S. bungeana community, analyzed the responses of above ground biomass to climate in different areas, and built a model of relationship between biomass and climatic factors. Results showed that there were significant differences for species diversity and above ground biomass among different sampling area. The species diversity range of S. bungeana was from 8.5 - 30.8 (ind/m2), and above ground biomass range was from 407.3 - 817.3 (g/m2) among studied area. The optimal distribution altitude range for S. bungeana is 1400 - 2000 m in arid area, 1200 - 1900 m in semi-arid area, and 600 - 1600 m in semi-humid area. Results also showed that the growth of S. bungeana was affected by different climatic factors, with rainfall as the major factor. Meanwhile, there was a close relationship between monthly biomass and rainfall during the growth stage. The models of monthly biomass and climate were built to compare the results and reveal the relationship between climatic factors and the growth of S. bungeana community.Key words: Stipa bungeana community, biomass model, species diversity, climatic factor, Loess Plateau.

The hot compression test was conducted in Gleeble-1 500D to study the hot flow stress behavior of AA6 111 aluminum alloy belonging to Al-Mg-Si series, at the deformation temperatures ranging from 350 to 500 °C and strain rates ranging from 0,01 s-1 to 1 s-1. And how the flow stress change with variation of strain, temperature and strain rate was investigated. The results show that flow stress increases with decreasing temperature and increasing strain rate; the AA6 111 is positive stain rate sensitive material; the main softening mechanism is dynamic recovery. Furthermore, constitutive equation considering the effect of strain was obtained based on Arrhenius equation. The predicted flow stress values well agree with the experimental results with some little aberration. The coefficient of association can be as high as 0,9 954, which shows high reference value for industry and simulation analysis.