Interaction effect in two-dimensional Dirac fermions

Based on the Dirac equations in the two-dimensional $\pi-$ flux model, we study the interaction effects both in nontrivial gapped and gapless Dirac equations with numerical exact diagonalization method. In the presence of the nearest and next nearest neighbor interactions: for nontrivial gapped Dirac equation, the topological phase is robust and persists in a finite region of the phase diagram; while for gapless Dirac equation, charge-density-wave and stripe phases are identified and the phase diagram in $(V_1, V_2)$ plane is obtained. When the next-next-nearest neighbor interaction is further included to gapless Dirac equation, the topological phase expected in the mean-field theory is absent. Our results are related to the possibility of dynamically generating topological phase from the electronic correlations.Comment: 7 pages, 8 figures. More discussins are added; accepted for publication in Physical Review

Advanced Intelligent Control in Robots

[Abstract not available.

Research on mechanical design of a multi-function finger rehabilitation robot

Training with robots for injured fingers has achieved the efficacy of treatment. However, most of finger rehabilitation robots just have bending/extending movement. This paper presents a new multi-function finger rehabilitation robot with a simple mechanical structure, which could help fingers and thumb realize bending/extending movement and stretch/adduction movement. The paper firstly analyzes the hand physiological movement mechanism, confirming the motion range of each finger’s joint. Based on the fingers movement rules, the robot driving structure has been developed, which includes thumb training module and fingers training module and frame. In order to prove the rationality of mechanism design, an experiment was conducted. The experiment proved that the mechanism can run smoothly, and its rope wheels also drive well without skidding phenomenon as well as its tension is appropriate

Mechanical design and trajectory planning of a lower limb rehabilitation robot with a variable workspace

The early phase of extremity rehabilitation training has high potential impact for stroke patients. However, most of the lower limb rehabilitation robots in hospitals are proposed just suitable for patients at the middle or later recovery stage. This article investigates a new sitting/lying multi-joint lower limb rehabilitation robot. It can be used at all recovery stages, including the initial stage. Based on man–machine engineering and the innovative design for mechanism, the leg length of the lower limb rehabilitation robot is automatically adjusted to fit patients with different heights. The lower limb rehabilitation robot is a typical human–machine system, and the limb safety of the patient is the most important principle to be considered in its design. The hip joint rotation ranges are different in people’s sitting and lying postures. Different training postures cannot make the training workspace unique. Besides the leg lengths and joint rotation angles varied with different patients, the idea of variable workspace of the lower limb rehabilitation robot is first proposed. Based on the variable workspace, three trajectory planning methods are developed. In order to verify the trajectory planning methods, an experimental study has been conducted. Theoretical and actual curves of the hip rotation, knee rotation, and leg mechanism end point motion trajectories are obtained for three unimpaired subjects. Most importantly, a clinical trial demonstrated the safety and feasibility of the proposed lower limb rehabilitation robot

Active Triggering of Pneumatic Rehabilitation Gloves Based on Surface Electromyography Sensors

The portable and inexpensive hand rehabilitation robot has become a practical rehabilitation device for patients with hand dysfunction. A pneumatic rehabilitation glove with an active trigger control system is proposed, which is based on surface electromyography (sEMG) signals. It can trigger the hand movement based on the patient's hand movement trend, which may improve the enthusiasm and efficiency of patient training. Firstly, analysis of sEMG sensor installation position on human's arm and signal acquisition process was carried out. Then according to the statistical law, three optimal eigenvalues of sEMG signals were selected as the follow-up neural network classification input. Using the back propagation (BP) neural network, the classifier of hand movement is established. Moreover, the mapping relationship between hand sEMG signals and hand actions is built by training and testing. According to individual differences, the corresponding BP neural network model database of different people was established. Finally, based on sEMG signal trigger, the pneumatic glove training control algorithm was proposed. The combination of the trigger signal waveform and the motion signal waveform indicates that the pneumatic rehabilitation glove is triggered to drive the patient's hand movement. Preliminary tests have confirmed that the device has a high accuracy rate of trend recognition for hand movement. In the future, clinical trials of patients will be conducted to prove the effectiveness of this system

The Gut Microbiome Signatures Discriminate Healthy From Pulmonary Tuberculosis Patients

Cross talk occurs between the human gut and the lung through a gut-lung axis involving the gut microbiota. However, the signatures of the human gut microbiota after active Mycobacterium tuberculosis infection have not been fully understood. Here, we investigated changes in the gut microbiota in tuberculosis (TB) patients by shotgun sequencing the gut microbiomes of 31 healthy controls and 46 patients. We observed a dramatic changes in gut microbiota in tuberculosis patients as reflected by significant decreases in species number and microbial diversity. The gut microbiota of TB patients were mostly featured by the striking decrease of short-chain fatty acids (SCFAs)-producingbacteria as well as associated metabolic pathways. A classification model based on the abundance of three species, Haemophilus parainfluenzae, Roseburia inulinivorans, and Roseburia hominis, performed well for discriminating between healthy and diseased patients. Additionally, the healthy and diseased states can be distinguished by SNPs in the species of B. vulgatus. We present a comprehensive profile of changes in the microbiota in clinical TB patients. Our findings will shed light on the design of future diagnoses and treatments for M. tuberculosis infections

Improving anthropomorphic robot stability using advanced intelligent control interfaces

The article focused on the advanced intelligent control of the stability of anthropomorphic walking robots (AWRs), in order to validate a new and useful method of moving in the virtual environment, which determines a substantial increase in their stability. The obtained results lead to Versatile Intelligent Portable Robot Platform VIPRO, developed to improve the walking anthropomorphic robots’ performances, provide unlimited power for design, test, experiment the real time control methods by integrating the Intelligent Control Interfaces (ICIs) in robot modeling and simulation for all types of humanoid robots, rescue robots, firefighting robots

Structure of p300 bound to MEF2 on DNA reveals a mechanism of enhanceosome assembly

Transcription co-activators CBP and p300 are recruited by sequence-specific transcription factors to specific genomic loci to control gene expression. A highly conserved domain in CBP/p300, the TAZ2 domain, mediates direct interaction with a variety of transcription factors including the myocyte enhancer factor 2 (MEF2). Here we report the crystal structure of a ternary complex of the p300 TAZ2 domain bound to MEF2 on DNA at 2.2Å resolution. The structure reveals three MEF2:DNA complexes binding to different sites of the TAZ2 domain. Using structure-guided mutations and a mammalian two-hybrid assay, we show that all three interfaces contribute to the binding of MEF2 to p300, suggesting that p300 may use one of the three interfaces to interact with MEF2 in different cellular contexts and that one p300 can bind three MEF2:DNA complexes simultaneously. These studies, together with previously characterized TAZ2 complexes bound to different transcription factors, demonstrate the potency and versatility of TAZ2 in protein–protein interactions. Our results also support a model wherein p300 promotes the assembly of a higher-order enhanceosome by simultaneous interactions with multiple DNA-bound transcription factors