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Abstract: Food quality and availability are important factors influencing the survival and reproduction of animals. The aim of the present study was to examine the effect of dietary fiber content [...]

OBJECTIVE: The aim of this study was to explore the influence of micro ribonucleic acid (miR)-29 on neuronal apoptosis in rats with cerebral infarction by regulating the protein kinase B (Akt) signaling pathway. MATERIALS AND METHODS: A total of 36 Sprague-Dawley rats were randomly divided into three groups, including: Sham group (n=12), Model group (n=12), and Inhibitor group (n=12). Common carotid artery, external carotid artery, and internal carotid artery were only exposed in the Sham group. However, the ischemia-reperfusion model was established by the suture method in the other two groups. After modeling, artificial cerebrospinal fluid was injected into the lateral ventricle in the rats of the Sham and Model groups. Similarly, miR-29 inhibitor was injected into the lateral ventricle in the rats of the Inhibitor group. At 24 h postoperatively, the sampling was performed. Zea-Longa score was used to evaluate the neurological deficit of rats. Meanwhile, the expressions of B-cell lymphoma 2 (Bcl-2) and Bcl-2 associated X protein (Bax) in cerebral tissues were detected via immunohistochemistry. The protein expression levels of Akt and phosphorylated Akt (p-Akt) were determined using Western blotting. Furthermore, the expression of miR-29 and cell apoptosis were detected via quantitative Polymerase Chain Reaction (qPCR) and terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) assay, respectively. RESULTS: Compared with Sham group, Model, and Inhibitor groups had substantially raised the Zea-Longa scores (p<0.05). The Zea-Longa score in the Model group was markedly lower than that of the Inhibitor group (p<0.05). The positive expression level of Bax was remarkably upregulated (p<0.05). However, the positive expression level of Bcl-2 declined dramatically in both Model group and Inhibitor group when compared with the Sham group (p<0.05). Besides, the Model group exhibited significantly lower positive expression level of Bax and higher positive expression level of Bcl-2 than the Inhibitor group (p<0.05). The relative protein expression level of p-Akt markedly increased in the Model and Inhibitor groups when compared with the Sham group (p<0.05). However, it was considerably higher in the Model group than that of the Inhibitor group (p<0.05). In comparison with the Sham group, both Model group and Inhibitor group exerted substantially elevated expression level of miR-29 (p<0.05). The relative expression level of miR-29 in the Model group was significantly upregulated when compared with the Inhibitor group (p<0.05). The apoptosis rate of cells in both Model group and Inhibitor group was markedly higher than that of the Sham group (p<0.05). Furthermore, the Model group showed remarkably lower apoptosis rate than the Inhibitor group (p<0.05). CONCLUSIONS: MiR-29 inhibits neuronal apoptosis in cerebral infarction rats by upregulating the Akt signaling pathway, thereby serving as a protector. [ABSTRACT FROM AUTHOR]

Brake disc with textured surface was introduced for fade resistance during braking process. The microdimple arrays of disc surface were fabricated by laser peening process, which can not only increase surface roughness but also accelerate heat dissipation, in turn, to raise friction coefficient of brake system and resist heat fade phenomenon through reducing the interface temperature of brake disc. Analysis of brake disc temperature distribution during single braking process under non-axisymmetric load was conducted by using finite element method (FEM) and the coupled heat conduction and elastic equations were solved with contact problems. The computational results showed that the value of temperature in radial direction of dimpled disc proved to be lower than smooth disc obviously. Heat fade and premature wear could be effectively relieved because the laser textured surfaces exerted an essential influence on the disc surface temperature distribution and the maximal contact temperature. [ABSTRACT FROM AUTHOR]

The effects of warm laser peening at different treating temperatures on damping capacity of Ti-6Al-4V titanium alloy were investigated based on the experimental study, the mechanism of damping capacity improvement on Ti-6Al-4V alloy treated by warm laser peening was discussed; moreover, the compressive residual stress (CRS) and its relaxation under vibration condition were simulated by finite element method (FEM), the stability of residual stress in Ti-6Al-4V titanium alloy subjected to warm laser peening processing was revealed based on the creep theory. It is shown that high dislocation density obtained by warm laser peening under the temperature of dynamic strain aging (DSA) is a critical factor for damping capacity improvement. Owing to higher damping capacity introduced by warm laser peening, the vibration stress is reduced and thus causes a lower creep rate and a slower residual stress relaxation speed than laser peening at room temperature. [ABSTRACT FROM AUTHOR]

To test the hypothesis that mammals that show decrease in body mass under short-day condition should be resistant to high-fat induced obesity, we traced the changes of energy balance in a wild rodent,Apodemus chevrieri, which were acclimated to either long day [16 light (L):8 dark (D), LD] or short day (8 L:16D, SD) and fed either a low-fat diet (LFD) or high-fat diet (HFD) in each photoperiodic manipulation. We found thatA. chevrieriwas not resistant to high-fat diet-induced obesity, and SD, not HFD, induced the elevation in basal metabolic rate (BMR), nonshivering thermogenesis (NST) and uncoupling protein-1 (UCP1) content in brown adipose tissue (BAT). HFD caused the increase in apparent digestibility and body fat mass, and the decrease in energy intake in both LD and SDA. chevrieri. The enhancement of energy absorption associated with small intestine tissue recruitment can compensate the lower energy intake, which may contribute to the high-fat diet-induced body fat deposition. Thus, a decrease in body-weight gain without resistance to high-fat induced obesity implies an evolutionary and adaptive mechanism, which is a benefit for their winter survival. [ABSTRACT FROM AUTHOR]