Application of Foot Hallux Contact Force Signal for Assistive Hand Fine Control.

Accurate recognition of disabled persons' behavioral intentions is the key to reconstructing hand function. Their intentions can be understood to some extent by electromyography (EMG), electroencephalogram (EEG), and arm movements, but they are not reliable enough to be generally accepted. In this paper, characteristics of foot contact force signals are investigated, and a method of expressing grasping intentions based on hallux (big toe) touch sense is proposed. First, force signals acquisition methods and devices are investigated and designed. By analyzing characteristics of signals in different areas of the foot, the hallux is selected. The peak number and other characteristic parameters are used to characterize signals, which can significantly express grasping intentions. Second, considering complex and fine tasks of the assistive hand, a posture control method is proposed. Based on this, many human-in-the-loop experiments are conducted using human-computer interaction methods. The results showed that people with hand disabilities could accurately express their grasping intentions through their toes, and could accurately grasp objects of different sizes, shapes, and hardness using their feet. The accuracy of the action completion for single-handed and double-handed disabled individuals was 99% and 98%, respectively. This proves that the method of using toe tactile sensation for assisting disabled individuals in hand control can help them complete daily fine motor activities. The method is easily acceptable in terms of reliability, unobtrusiveness, and aesthetics.

Research on Intelligent Wheelchair Attitude-Based Adjustment Method Based on Action Intention Recognition.

At present, research on intelligent wheelchairs mostly focuses on motion control, while research on attitude-based adjustment is relatively insufficient. The existing methods for adjusting wheelchair posture generally lack collaborative control and good human-machine collaboration. This article proposes an intelligent wheelchair posture-adjustment method based on action intention recognition by studying the relationship between the force changes on the contact surface between the human body and the wheelchair and the action intention. This method is applied to a multi-part adjustable electric wheelchair, which is equipped with multiple force sensors to collect pressure information from various parts of the passenger's body. The upper level of the system converts the pressure data into the form of a pressure distribution map, extracts the shape features using the VIT deep learning model, identifies and classifies them, and ultimately identifies the action intentions of the passengers. Based on different action intentions, the electric actuator is controlled to adjust the wheelchair posture. After testing, this method can effectively collect the body pressure data of passengers, with an accuracy of over 95% for the three common intentions of lying down, sitting up, and standing up. The wheelchair can adjust its posture based on the recognition results. By adjusting the wheelchair posture through this method, users do not need to wear additional equipment and are less affected by the external environment. The target function can be achieved with simple learning, which has good human-machine collaboration and can solve the problem of some people having difficulty adjusting the wheelchair posture independently during wheelchair use.

Activation of NADPH/ROS pathway contributes to angiogenesis through JNK signaling in brain endothelial cells.

Recent evidences have shown that reactive oxygen species (ROS) are involved in regulating angiogenesis and preventing tissue injury. However, the precise molecular mechanisms behind ROS-induced angiogenesis are still unknown. The aim of the present study was to investigate the effects of ROS-induced angiogenesis in rat brain microvessel endothelial cells (rBMECs) and identify involving the signal pathways. For initial experiments, the rBMECs were incubated with different concentrations of hydrogen peroxide (H2O2). For the second experiments, the rBMECs were respectively treated with ROS scavenger dimethylthiourea (DMTU), NADPH oxidase (Nox) inhibitor apocynin, small interfering RNAs-mediated knock down Nox2 or Nox4, or pretreated with c-Jun N-terminal kinase (JNK) inhibitor SP600125. The cell proliferation, migration, tube formation, and the expressions of several important neuroangiogenic factors including vascular endothelial growth factor (VEGF), brain derived neurotrophic factor (BDNF), matrix metalloproteinase (MMP) -9 and phos-JNK were measured. Low level of H2O2 significantly promoted endothelial cell (EC) proliferation, migration and tube formation and upregulated levels of VEGF, BDNF, MMP-9 and phos-JNK. DMTU and apocynin significantly inhibited endothelial angiogenesis and downregulated these protein levels. As expected, knockdown of Nox2 or Nox4 expression blocked endothelial angiogenesis and downregulated the expressions of pro-neuroangiogenic factors. Furthermore, H2O2-induced endothelial angiogenesis and high expressions of pro-neuroangiogenic factors were decreased by SP600125. In conclusion, Nox-derived ROS were required for endothelial angiogenesis. Low level of ROS may activate JNK signaling pathway and upregulate pro-neuroangiogenic factors, ultimately mediating endothelial angiogenesis.

[Virtual screening and antibacterial activity of lead compounds targeting to penicillin-binding protein 3 (PBP3) of Pseudomonas aeruginosa].

OBJECTIVE: This study was carried out to obtain lead compounds targeting penicillin-binding protein 3 (PBP3) of Pseudomonas aeruginosa by virtual screening. METHODS: UCSF dock 6.5 was used for the virtual screening from a database containing 1.04 million small molecules. Hit compounds with simple structures were synthesized and then evaluated for their antibacterial activities. RESULTS: Grid score was used for the first round of screening, and 60000 small molecules whose scores lower than -30 kcal/mol were screened out from the database. These molecules were subjected to the second round of screening using amber score. Approximately 200 hit compounds with scores lower than -20 kcal/mol were analyzed and 4 of them were selected as lead compounds and then synthesized. The minimal inhibition concentrations (MICs) of the lead compounds were between 175-275 µg/mL, which were lower than that of Sulfadiazine (500 µg/mL) significantly. Meanwhile, these compounds were effective for both Gram-negative and Gram-positive bacteria. CONCLUSION: The lead compounds had potential to become new antibacterial agents for conquering the drug resistance of P. aeruginosa.