Abstract: The anodic oxidation/TiO2 composite film was prepared on the surface of AZ31B Mg alloy by DC magnetron sputtering. The corrosion resistance and blood compatibility of the film were systematically studied by electrochemical, dynamic clotting time and platelet adhesion test. The results shows that the corrosion current of AZ31B Mg alloy was 6.409×10-8A/cm2 after anodic oxidation treatment, which has decreased 4 orders of magnitude compared to the untreated samples and the corrosion resistance is improved greatly. The clotting time of anodic oxidation/TiO2 film is about 53 min, which has increased 1.3 times compared to anodic oxidation film (40min). Platelets adhesion to anodic oxidation/TiO2 film are less than the one adhesion to anodic oxidation film, and there are no pseudopodia and aggregation, which indicate that the blood compatibility of anodic oxidation/TiO2 film is better than anodic oxidation film.
Abstract: Several problems in EEG-brain signal analysis are not solved, such as presence of an artifact during the recording process, particularly the eye artifact (ElectroOculoGram (EOG)) which makes the analysis of EEG-brain signals very difficult. Blind source separation technique is one of the important techniques used to clean the EEG signals from different types of artifacts. Independent component analysis (ICA) techniques are widely used for this purpose, but unfortunately the ICA techniques have inherent shortcoming such as source ambiguity and unordered components. Therefore, the researchers used ICA-Reference algorithm. The main problem in ICA-Reference algorithm is to find clean reference signal to extract the wanted signal. Recently, many algorithms proposed to generate the artifact reference, but unfortunately, clean artifact signal not satisfied. In this paper wavelet denoising technique is used to solve this problem by decompose the artifact reference signal into pure artifact signal and residual neural signal. The proposed algorithm used frontal channels instead of EOG channels to extract the EOG reference signal.
Abstract: The research of drag reduction technique have the advantages of saving energy and improving utilization rate, which behaves a tremendous value in economy and military, hence it is a hot issue for researchers all the time. Merging together with the method of bionic drag reduction, drag reduction mechanisms with flexible surface have realized its function by imitating the elastic characteristics of dolphin skin and using the interaction between flexible materials and boundary layer fluid. Development status of drag reduction technique with flexible surface was analysed, and its mechanisms were reviewed from two aspects of delayed transition and disturbance on boundary layer. In addition, drag reduction mechanisms with flexible surface were explored in terms of changing the structure in the boundary layer, moreover, its development tendency was prospected.
Abstract: Mobility is the urgent requisite of post spinal cord injury (SCI) patient. Since the alternative and compensatory approach is considered as the major function of mobility assistive device for post-SCI patients, the device should possess capability to acclimate to the ‘abnormal’ gait generate by the patients who usually undergo alternative and compensatory rehabilitation in their neural circuit. The functional ability of individual should be taking into account. Yet according to the requirement of neuro-protective treatment in post-SCI rehabilitation processing, locomotor-like activity is still an essential factor to patient. This study presents a novel concept and prototype of assistive technology base on foot control strategy to take an equilibrium between mobility and gait realization. To demonstrate that foot-induced over-ground locomotor assistive method is capable of achieving locomotor-like activity (dragging step), simulation analysis and prototype preliminary experiment have been conducted. Simulation analysis show that foot-induced assistance can allow more volitional activity compare to the hip-knee-induced assistive device. Yet the input and disturbance act on such kind of device may be increased. Surface electromyography (sEMG) from muscles of lower limb (right rectus femoris, right biceps femoris and right gluteus maximus) have been recorded during the preliminary experiment, and the mean of integrated EMG (iEMG) was used as evaluation of muscle activity. The result of the testing show that the mean of iEMG in the right gluteus maximus was reduced in the swing phase when the subject moving ahead with the prototype, but no significant change in the right rectus femoris. It may imply that foot-induced over-ground locomotor assistive device can reduce the muscle activity when patient complete locomotor-like movement and retain some amount of residual recruitment of lower limb, instead of substituting arbitrarily.
Abstract: Triptolide (TPL) is a traditional Chinese medicine and an active component of a Chinese herb Tripterygium wilfordii F. (Celastraceae). Triptolide has been used to treat a variety of ailments, including rheumatoid arthritis, nephritic syndrome and Lupus erythematosus. It is also a strong antitumor agent. Several angiogenesis assays in numerous research studies have shown that triptolide is an angiogenesis inhibitor. Numerous preclinical studies have shown that TPL inhibits cell proliferation, induces apoptosis and limits tumor metastasis. TPL also has a synergistic action with other treatment methods whereby, it enhances the effects of other antitumor treatments, as studied in various cancer cell lines. This review summarizes the recent developments and discussion of antiangiogenic mechanisms of TPL in cancer, brief outline of its clinical trials and its future in cancer therapeutics.
Abstract: Bio-inspiration focuses on translating the evolutionary successes of natural species into engineering systems that mimic the geometry, function, and performance of the natural system. In this paper we present a latest comprehensive review of ionic polymer metal composite (IPMC) biomedical and biomimetic applications. IPMC is becoming an increasingly popular material among scholars, engineers and scientists due to its inherent properties of low activation voltage, large bending strain, flexibility, softness, suitable response time which make them a strong candidate to be applied as artificial muscle in biomimetic land and underwater applications. Among the diversity of electro active polymers (EAPs), recently developed IPMCs are good candidates for use in bio-related application because of their biocompatibility. Several recently reported IPMC biomimetic applications have been reported in this paper. The applications of IPMC have been growing due to progression in its manufacturing techniques, development of more accurate response models and control techniques, and recently more sophisticated IPMC actuator applications have been performed. This indicates that the IPMC actuators hold potential for more sophisticated and controlled applications in fields of biomedical and biomimetic. Extensive references are provided for more indepth explanation.
Abstract: With the development of economy, the energy problem is becoming more and more seriously, which is closely related to resistance, and drag reduction means to save energy. Research on the technology of drag reduction plays an important role in the area of energy saving and its utilization rate enhancing. Using the method of bionic surface drag reduction to reduce the surface friction drag in a fluid medium has become a hot topic in the research area of drag reduction. Furthermore, through analyzing approaches of bionic surface drag reduction on the necessary of energy saving, energy utilization rate enhancing and drag reduction theory system improving, the research progress of the dynamic bionic non-smooth surfaces and bionic jet surface drag reduction technology are summarized in detail, the main trend of non-smooth drag reduction technology research and jet drag reduction technology is reviewed.
Abstract: IPMC is becoming an increasingly popular material among scholars, engineers and scientists due to its inherent properties of low activation voltage, large bending strain, flexibility, softness, suitable response time which make them a strong candidate to be applied as artificial muscle in biomimetic land and underwater applications. The applications of IPMC have been growing due to progression in its manufacturing techniques, development of more accurate response models and control techniques, and recently more sophisticated IPMC actuator applications have been performed. In this paper, a new application of IPMC is proposed to actuate aileron fins of a micro scanning device towed underwater by a surface vessel to control its depth and to stabilize it against roll motion that can mimic pectoral fins of fish that steer them up and down by changing their angle of rotation and their dorsal fins that keep them upright against roll. Same is applicable for autonomous underwater vehicles. Secondly, a three link mechanism is presented to actuate aileron fin through IPMC actuator. Three dimensional model of the mechanism is developed in Pro-Engineer CAD software tool and its kinematic analysis is performed. Thirdly, forward kinematic model of proposed mechanism, based on geometric coordinate, is presented. Lastly, results of kinematic analysis of proposed mechanism are compared to that of model to verify its design and kinematics. Encouraging results decoy the research team to manufacture the mechanism and to perform experiments for its practical application.
Abstract: The bone is a hierarchically structured material with mechanical properties depending on its architecture at all scales. Water plays an important role in the bio-mineralization process and serves as a plasticizer, enhancing the toughness of bone. In this paper, a trabecular bone multiscale model based on finite element analysis was developed to link scales from sub-nanoscopic scale (Microfibril) to sub-microscopic (Lamella) in order to predict the orthotropic properties of bone at different structural level. To identify the orthotropic properties, an inverse identification algorithm is used. Furthermore, the effect of water is incorporated. Good agreement is found between theoretical and experimental results.