21 research outputs found

    Cardioprotective Effect of Sodium Ferulate in Diabetic Rats

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    Reactive oxygen species (ROS) play important roles in the occurrence and development in diabetic cardiomyopathy (DC). Ferulic acid is one of the ubiquitous compounds in diet. Sodium ferulate (SF) is its sodium salt. SF has potent free radical scavenging activity and can effectively scavenge ROS. The study investigated the effect of SF on cardioprotection in diabetic rats. The diabetic rats induced by streptozotocin (STZ) were treated with SF (110mg/kg) by gavage per day for 12 weeks. Results showed that the levels of nitric oxide (NO) and superoxide dismutase (SOD) activity in plasma and myocardium in SF-treated group were significantly higher than those in diabetic control group. The levels of malondialdehyde (MDA) in plasma and myocardium in SF-treated group were significantly lower than those in diabetic control group. Expression of connective tissue growth factor (CTGF) in myocardium in SF-treated group was apparently lower than that in diabetic control group. Compared with normal control group, electron micrographs of myocardium in diabetic control group showed apparently abnormality, while that was significantly ameliorated in SF-treated group. The study demonstrated that SF has a cardioprotective effect via increasing SOD activity and NO levels in plasma and myocardium, inhibiting oxidative stress in plasma and myocardium, and inhibiting the expression of CTGF in myocardium in diabetes rats

    Research on a safety evaluation system for railway-tunnel structures by fuzzy comprehensive evaluation theory

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    Long-term health detection of railway-tunnel is the development direction and trend of future railway tunnel research. Based on the actual engineering of a railway tunnel, this study developed a safety evaluation model for railway tunnel structures using a fuzzy comprehensive evaluation method and examined a health state evaluation method suitable for most railway tunnel structures. The results showed that the evaluation method comprehensively reflected the impact of various factors, which had strong practicality. The evaluation results were clear, accurate, and consistent with engineering practice. When using the safety factor index to study the stress of a railway tunnel structure, Midas/civil analysis showed that different levels of the surrounding rock structural vault in railway tunnels were in a tensile, control-bearing capacity state. When calculating safety factors, the range of a 60° central angle of a railway tunnel vault was calculated according to the tensile control-bearing capacity. Theoretical formulas of the range of the center angle φ0 of the vault tension zone were derived and then verified by experiments and numerical analysis

    Bearing capacity and seismic performance of Y-shaped reinforced concrete bridge piers in a freeze-thaw environment

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    A quantitative study is performed to determine the performance degradation of Y-shaped reinforced concrete bridge piers owing to long-term freeze-thaw damage. The piers are discretized into spatial solid elements using the ANSYS Workbench finite element analysis software, and a spatial model is established. The analysis addresses the mechanical performance of the piers under monotonic loading, and their seismic performance under low-cycle repeated loading. The influence of the number of freeze-thaw cycles, axial compression ratio, and loading direction on the pier bearing capacity index and seismic performance index is investigated. The results show that freeze-thaw damage has an adverse effect on the ultimate bearing capacity and seismic performance of Y-shaped bridge piers in the transverse and longitudinal directions. The pier peak load and displacement ductility coefficient decrease with increasing number of freeze-thaw cycles. The axial compression ratio is an important factor that affects the pier ultimate bearing capacity and seismic performance. Upon increasing the axial compression ratio, the pier peak load increases and the displacement ductility coefficient decreases, the effects of which are more significant in the longitudinal direction

    Hypoxia-inducible factor-1α gene polymorphisms and cancer risk: a meta-analysis

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    <p>Abstract</p> <p>Background</p> <p>The results from the published studies on the association between <it>hypoxia-inducible factor -1α </it>(HIF-1α) polymorphisms and cancer risk are conflicting. In this meta-analysis, we aimed to investigate the association between <it>HIF-1α </it>1772 C/T and 1790 G/A polymorphisms and cancer.</p> <p>Methods</p> <p>The meta-analysis for 1772 C/T polymorphism included 4131 cancer cases and 5387 controls, and for 1790 G/A polymorphism included 2058 cancer cases and 3026 controls. Allelic and genotypic comparisons between cases and controls were evaluated. Subgroup analyses by cancer types, ethnicity, and gender were also performed. We included prostate cancer in male subgroup, and female specific cancers in female subgroup.</p> <p>Results</p> <p>For the 1772 C/T polymorphism, the analysis showed that the T allele and genotype TT were significantly associated with higher cancer risk: odds ratio (OR) = 1.29 [95% confidence interval (CI, 1.01, 1.65)], P = 0.04, P<sub>heterogeneity </sub>< 0.00001, and OR = 2.18 [95% CI (1.32, 3.62)], P = 0.003, P<sub>heterogeneity </sub>= 0.02, respectively. The effect of the genotype TT on cancer especially exists in Caucasians and female subjects: OR = 2.40 [95% CI (1.26, 4.59)], P = 0.008, P<sub>heterogeneity </sub>= 0.02, and OR = 3.60 [95% CI (1.17, 11.11)], P = 0.03, P<sub>heterogeneity </sub>= 0.02, respectively. For the 1790 G/A polymorphism, the pooled ORs for allelic frequency comparison and dominant model comparison suggested a significant association of 1790 G/A polymorphism with a decreased breast cancer risk: OR = 0.28 [95% CI (0.08, 0.90)], P = 0.03, P<sub>heterogeneity </sub>= 0.45, and OR = 0.29 [95% CI (0.09, 0.97)], P = 0.04, P<sub>heterogeneity </sub>= 0.41, respectively. The frequency of the <it>HIF-1α </it>1790 A allele was very low and only two studies were included in the breast cancer subgroup.</p> <p>Conclusions</p> <p>Our meta-analysis suggests that the <it>HIF-1α </it>1772 C/T polymorphism is significantly associated with higher cancer risk, and 1790 G/A polymorphism is significantly associated with decreased breast cancer risk. The effect of the 1772 C/T polymorphism on cancer especially exists in Caucasians and female subjects. Only female specific cancers were included in female subgroup, which indicates that the 1772 C/T polymorphism is significantly associated with an increased risk for female specific cancers. The association between the 1790 G/A polymorphism and lower breast cancer risk could be due to chance.</p
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