Polysaccharides are important pharmacologically active substances found in the perennial orchid Dendrobium huoshanense. In the present study, we sought to determine whether antioxidant and anti-inflammatory mechanisms were involved in Dendrobium huoshanense polysaccharides (DHPs)-mediated protection from D-galactose-induced intestine injury in an aging rat model. The effects of DHPs on ileal antioxidant capacity, mucosal barrier integrity and the inflammatory response were investigated in D-galactose-treated rats. The results showed that DHP administration largely attenuated the D-galactose-induced malondialdehyde (MDA), interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-4, IL-10, Toll-like receptor four and NF-κBp65 content increases and also markedly renewed the total antioxidant capacity and the claudin and occludin contents of ileal tissues from the D-galactose-treated rats. We also found that DHP more markedly affected the IL-6 and TNF-α levels than it did the IL-4 and IL-10 levels in the ileal tissues from the D-galactose-treated rats. These results suggest that DHPs can protect the rat ileum from D-galactose-induced injury by attenuating lipid peroxidation, improving antioxidant capacity and mucosal barrier integrity, correcting imbalanced inflammatory cytokine networks and suppressing the inflammatory response. The novel insights into the mechanism involved in DHPs protection of ileal health in our D-galactose-induced aging model rat advances current understanding of the aging process.
For effective energy regeneration and vibration dampening, energy regenerative suspension systems have received more studies recently. This paper presents the dynamic modeling and a test system of a regenerative shock absorber system which converts vibration motion into rotary motion through the adjustment of hydraulic flow. Hydraulic circuit configuration achieves the one way flow and energy regeneration during both compression and extension strokes. The dynamic modeling is performed for the evaluation of design concept and the feasibility studies of regenerative shock absorber system theoretically. Based on simulated results, the efficiency of hydraulic transmission is optimized and validated in test system. The results show that the performance of hydraulic fluid, the features of rotary motion and the capability of energy regeneration are verified and compared between dynamic modeling and experiments. Meanwhile, the average power of 118.2W and 201.7W with the total energy conversion of 26.86% and 18.49% can be obtained based on experiments under sinusoidal inputs with 0.07854m/s and 0.1256m/s respectively.
The extract of Dendrobium huoshanense, a traditional Chinese medicinal and food homologous plant belonging to the family Orchidaceae, was previously reported to have hypoglycemic and antioxidant effects. In this study, the direct effects of polysaccharide (DHP) and non-polysaccharide (NDHP) components of D. huoshanense, as well as its water extract (DHWE) were compared with that of metformin (an antidiabetic drug) on the gut microbiota (collected from fecal flora) of rats with streptozotocin-induced type 1 diabetes (T1D) using an in vitro fermentation method. The results showed that DHWE, DHP, and NDHP reduced pH and increased bacterial proliferation and short-chain fatty acid (SCFA) content in fermentation broth. DHWE, DHP, NDHP and metformin promoted the production of acetic and propionic acid, acetic acid, propionic acid and butyric acid, and propionic acid, respectively. DHWE, DHP, and NDHP reduced the abundance of Proteobacteria (subdominant pathogenic bacteria) and increased the abundance of Firmicutes (dominant beneficial gut bacteria). NDHP also reduced the abundance of Bacteroidetes (beneficial and conditional pathogenic). Metformin increased the abundance of Proteobacteria and reduced the abundance of Firmicutes and Bacteroidetes. At the genus level, NDHP promoted the proliferation of Megamonas and Megasphaera and decreased harmful bacteria (e.g., Klebsiella), and DHP increased the abundance of Prevotellaceae (opportunistic and usually harmless). By contrast, metformin increased the abundance of harmful bacteria (e.g., Citrobacter) and reduced the abundance of beneficial bacteria (e.g., Oscillospira). Our study indicates that DHWE, DHP, and NDHP are potentially more beneficial than metformin on the gut microbiota of T1D rats in vitro.
Search and rescue missions require robots possess high speed and efficiency on both even and rough terrains. Hybrid robots that combine the advantages of different locomotion mechanisms are developed to solve this problem. Yet the design of previous research is usually complicated because they have separate wheels, tracks and legs. In this paper, a novel wheel-track-leg hybrid robot that has simple morphology is presented. By utilizing a transformable rim, the robot wheels can switch to tracks or legs according to different grounds. We cut the wheel rim into several segments and joint the ends, which makes the rim foldable. Mode-switch is achieved by the folding or unfolding of the transformable rim, so that no separate wheel, track, or leg is needed. We conduct a geometry configuration analysis and propose two optional design of the transformable wheel. By comparison the supposed better one is chosen and an initial prototype is fabricated to verify the transformation of the rim and basic function of the robot.