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The accumulation and incineration of waste tires have caused great damage to the environment. Therefore, recycling waste tires efficiently and economically has become an important issue in protecting world resources and the environment. In this study, 5%, 10%, and 15% rubber particles were used to replace fine sand in concrete, and basalt fibers (0.1%, 0.2%, and 0.3%) and polypropylene fibers (0.1%, 0.15%, and 0.2%) were added to rubber concrete to prepare hybrid fiber rubber concrete (HFRC). The experiments investigated the changes of mechanical properties of basalt (BF), polypropylene (PPF) fibers, and rubber particles when they were blended into concrete respectively, and the degree of influence of each factor on the mechanical and carbonation resistance of HFRC was investigated based on the orthogonal test. The results show that the rubber concrete’s mechanical and carbonation properties are improved to varying degrees after adding hybrid fibers. When the basalt fiber content is 0.2% and the polypropylene fiber content is 0.15%, the overall mechanical properties of HFRC reach the best state. When the basalt fiber content is 0.2%, the polypropylene fiber content is 0.15%, and the rubber content is 5%, the carbonation resistance of HFRC is the most ideal. In addition, the microstructure of HFRC was observed by scanning electron microscope.

Objective To explore the effect of inhibiting miR-155 on cardiomyocyte apoptosis and inflammation in myocardial ischemia-reperfusion (MI/R) model. Methods Myocardial cells of H9c2 rats were divided into four groups: blank control group, myocardial ischemia-reperfusion group (MI/R group), negative control group and miR-155 inhibitor group. The expressions of miR-155, NF-κB signaling pathway related genes and Bax, Bcl-2 mRNA were detected by RT-qPCR. The contents of IL-8 and TNF-α were detected by ELISA. Western blot was used to detect the expression of NF-κB signaling pathway related genes and Bax, Bcl-2 protein. Results Compared with the control group, the expression of miR-155 in MI/R group was significantly increased (P＜0.05) while the expression of miR-155 in miR-155 inhibitor group was significantly decreased (P＜0.05). In MI/R group, the apoptosis rate, the content of IL-8 and TNF-α, the protein and mRNA expression of Bax and NF-κB signal pathway were significantly higher than those in the control group, while the protein and mRNA expression of Bcl-2 were lower (P＜0.05). After inhibition the expression of miR-155, the apoptosis rate, the content of IL-8 and TNF-α, the protein and mRNA expression level of Bax and NF-κB signal pathway related gene were significantly decreased, while the protein and mRNA expression by Bcl-2 were increased (P＜0.05). Conclusions Inhibition of miR-155 expression can protect MI/R injury through inhibition of apoptosis and inflammation. The potential mechanism is the inhibition of the activation of NF-κB signaling pathway.

Objective To analyze the relationship among electrical conductivity （EC）, total volatile basic nitrogen （TVB-N）, which is an index of decomposition rate for meat production, and postmortem interval （PMI）. To explore the feasibility of EC as an index of cadaveric skeletal muscle decomposition rate and lay the foundation for PMI estimation. Methods Healthy Sprague-Dawley rats were sacrificed by cervical vertebrae dislocation and kept at 28 ℃. Muscle of rear limbs was removed at different PMI, homogenized in deionized water and then skeletal extraction liquid of mass concentration 0.1 g/mL was prepared. EC and TVB-N of extraction liquid were separately determined. The correlation between EC （x1） and TVB-N （x2） was analyzed, and their regression function was established. The relationship between PMI （y） and these two parameters were studied, and their regression functions were separately established. Results The change trends of EC and TVB-N of skeletal extraction liquid at different PMI were almost the same, and there was a linear positive correlation between them. The regression equation was x2=0.14 x1-164.91 （R2=0.982）. EC and TVB-N of skeletal muscle changed significantly with PMI, and the regression functions were y=19.38 x13-370.68 x12+2 526.03 x1-717.06 （R2=0.994）, and y=2.56 x23-48.39 x22+ 330.60 x2-255.04（R2=0.997）, respectively. Conclusion EC and TVB-N of rat postmortem skeletal muscle show similar change trends, which can be used as an index for decomposition rate of cadaveric skeletal muscle and provide a method for further study of late PMI estimation.

To further study the distribution and concentration of Bi particles in various cooling zones in newly solidified Bi content 1215 MS steels and to explore the relationship between cooling rate (R) and dendrite arm spacing, the horizontal solidification experiments were carried out by altering the R. Thermodynamics show liquid Bi was immiscible in Fe, which precipitated in the grain boundary and tended to co-exist with sulfides. Under moving rate ν = 0.2 mm/s, the average sizes of Bi particles and Bi-MnS inclusions in the chilled boundary, columnar grain and quenching grain zones were 1.2 μm, 1.4 μm, and 1.5 μm, while under v = 0.4 mm/s, those were 1.3 μm, 1.6 μm, and 1.2 μm, respectively. The average dendrite arm spacing of the solidified steel decreased with increasing moving rate (v). At R = 0.367 and 0.690°C/s, the average equivalent diameter ( d ˉ e ) of the inclusions in the columnar grain zone was respectively 1.102 μm and 1.119 μm. Under v = 0.4 mm/s, the concentrations of Bi particles in 1200 ppm and 2800 ppm Bi solidified steels in the chilled boundary, solidification front and center of the quenching grain zone were 0.0267%, 0.0375%, 0.0443%, 0.0463%, 0.0659%, and 0.0832%, respectively. [ABSTRACT FROM AUTHOR]