Korea Lift College

Mori Ramulus, the dried twigs of Morus alba L., has been attracting attention for its potent antioxidant activity, but its role in muscle cells has not yet been elucidated. The purpose of this study was to evaluate the protective effect of aqueous extracts of Mori Ramulus (AEMR) against oxidative stress caused by hydrogen peroxide (H2O2) in C2C12 mouse myoblasts, and in dexamethasone (DEX)-induced muscle atrophied models. Our results showed that AEMR rescued H2O2-induced cell viability loss and the collapse of the mitochondria membrane potential. AEMR was also able to activate AMP-activated protein kinase (AMPK) in H2O2-treated C2C12 cells, whereas compound C, a pharmacological inhibitor of AMPK, blocked the protective effects of AEMR. In addition, H2O2-triggered DNA damage was markedly attenuated in the presence of AEMR, which was associated with the inhibition of reactive oxygen species (ROS) generation. Further studies showed that AEMR inhibited cytochrome c release from mitochondria into the cytoplasm, and Bcl-2 suppression and Bax activation induced by H2O2. Furthermore, AEMR diminished H2O2-induced activation of caspase-3, which was associated with the ability of AEMR to block the degradation of poly (ADP-ribose) polymerase, thereby attenuating H2O2-induced apoptosis. However, compound C greatly abolished the protective effect of AEMR against H2O2-induced C2C12 cell apoptosis, including the restoration of mitochondrial dysfunction. Taken together, these results demonstrate that AEMR could protect C2C12 myoblasts from oxidative damage by maintaining mitochondrial function while eliminating ROS, at least with activation of the AMPK signaling pathway. In addition, oral administration of AEMR alleviated gastrocnemius and soleus muscle loss in DEX-induced muscle atrophied rats. Our findings support that AEMR might be a promising therapeutic candidate for treating oxidative stress-mediated myoblast injury and muscle atrophy.

Isorhamnetin, which is a flavonoid predominantly found in fruits and leaves of various plants, including Hippophae rhamnoides L. and Oenanthe javanica (Blume) DC, is known to possess various pharmacological effects. However, the anti-inflammatory potential of isorhamnetin remains poorly studied. Therefore, the present study aimed to investigate the inhibitory potential of isorhamnetin against inflammatory responses in lipopolysaccharide (LPS)-stimulated BV2 microglia. To measure the effects of isorhamnetin on inflammatory mediators and cytokines, and reactive oxygen species (ROS) generation, the following methods were used: cell viability assay, griess assay, ELISA, reverse transcriptase-polymerase chain reaction, flow cytometry, western blotting and immunofluorescence staining. The results revealed that isorhamnetin significantly suppressed LPS-induced secretion of pro-inflammatory mediators, including nitric oxide (NO) and prostaglandin E2, without exhibiting significant cytotoxicity. Consistent with these results, isorhamnetin inhibited LPS-stimulated expression of regulatory enzymes, including inducible NO synthase and cyclooxygenase-2 in BV2 cells. Isorhamnetin also downregulated LPS-induced production and expression of pro-inflammatory cytokines, such as tumor necrosis factor-α and interleukin-1β. The mechanism underlying the anti-inflammatory effects of isorhamnetin was subsequently evaluated; this flavonoid inhibited the nuclear factor (NF)-κB signaling pathway by disrupting degradation and phosphorylation of inhibitor κB-α in the cytoplasm and blocking translocation of NF-κB p65 into the nucleus. In addition, isorhamnetin effectively suppressed LPS-induced expression of Toll-like receptor 4 (TLR4) and myeloid differentiation factor 88. It also suppressed the binding of LPS with TLR4 in BV2 cells. Furthermore, isorhamnetin markedly reduced LPS-induced generation of ROS in BV2 cells, thus indicating a strong antioxidative effect. Collectively, these results suggested that isorhamnetin may suppress LPS-mediated inflammatory action in BV2 microglia through inactivating the NF-κB signaling pathway, antagonizing TLR4 and eliminating ROS accumulation. Further studies are required to fully understand the anti-inflammatory effects associated with the antioxidant capacity of isorhamnetin; however, the findings of the present study suggested that isorhamnetin may have potential benefits in inhibiting the onset and treatment of neuroinflammatory diseases.

This paper analyzes the influence of lubricating oil film of the low-speed and heavy-load sliding bearing on a variety of factors. It introduces the operation of Bearing for lubricating oil film in monitoring method, common fault causes and treatment measures. Finally, the bearing cooling system structure is discussed, providing reference for practical engineering application. There are many reasons to cause the failure of the bearing lubrication such as bearing assembly defects, the error of size and cooling system problems. By detecting and contrast parameters, this study analyze the determine data and correct the fault. Through the use of reasonable structure of the oil tank and cooling water channel, we can improve the lubrication performance, and extend the bearing life. This paper analyzes the factors restricting the low speed and high load sliding bearing lubricant film, and solves the actual bearing lubrication problem.

For medium range temperature applications, focusing type collectors like Compound Parabolic Concentrator (CPC) are most commonly used. Considerable research work has been carried out to improve the performance of the two-dimensional compound parabolic concentrator (2D CPC). The three-dimensional compound parabolic concentrator (3D CPC) was found to be more efficient than 2D CPC because of the higher concentration ratio. In the present work a 3D CPC was fabricated with a half acceptance angle of 4° for a spherical absorber of radius 100 mm. UV stabilized aluminized polyester foil having high reflectivity (0·85) was pasted on the reflector for a total height of 441mm and an aperture width of 540 mm. The optical efficiency was estimated theoretically and compared with the experimental value. Experimentally determined values of optical and thermal efficiencies were in good agreement with theoretically predicted value. The experimental results shown that the optical efficiency obtained from the 3D CPC (0·626) was significantly higher than that of the 2D CPC (0·570) of similar dimensions. Since the optical efficiency of the 3D CPC was increased, the thermal efficiency of the collector was also increased. In addition to that, time constant of the concentrator was also calculated. The time constant of the 3D CPC (431 s) was fairly high when compared with the 2D CPC (110 s). An attempt was made to generate low pressure steam using 3D CPC in the in situ steam generation mode. The efficiency of the steam generation was about 38%, which was one of the possible applications of 3D CPC module.

In Teleoperation, it is important to let operator know the situation of remote place correctly. We improve operability of Teleoperation with Force Feedback using Haptic Interface in this research. If there are a lot of tasks in the remote place, it is necessary to change Force Feedback method according to each task. In this paper, we propose variable force display method based on tasks in Teleoperation.

Ti-Al intermetallic compounds are promising materials for structural application. Processing of Ti/Ti-Al layered materials by self-propagating high temperature synthesis was tried in order to enhance the crack propagation resistance of intermetallics. Tensile test, three-point fracture toughness test and in-situ observation of crack propagation were employed in these materials, and the effect of microstructure and volume fraction of intermetallic layer on the crack propagation behavior was investigated and this paper was aimed at understanding the fracture mechanism of these materials. Tensile strength was increased with the decrease of volume fraction of intermetallics layer, and the materials with many microcracks during tensile test demonstrated higher elongation regardless of the volume fraction of intermetallic layer. The crack propagation resistance curve was quantitatively predicted from the contribution of bridging mechanism in the materials where crack propagates forward during fracture toughness test. The proposed criterion for crack propagation orientation could also predict whether crack propagates forward or deflects in the intermetallic layer.