The present study was aimed at the optimal solution of the main muscular force distribution in the lower extremity during standing balance of human. The movement musculoskeletal system of lower extremity was simplified to a physical model with 3 joints and 9 muscles. Then on the basis of this model, an optimum mathematical model was built up to solve the problem of redundant muscle forces. Particle swarm optimization (PSO) algorithm is used to calculate the single objective and multi-objective problem respectively. The numerical results indicated that the multi-objective optimization could be more reasonable to obtain the distribution and variation of the 9 muscular forces. Finally, the coordination of each muscle group during maintaining standing balance under the passive movement was qualitatively analyzed using the simulation results obtained.
Algorithms ; Gait ; Humans ; Joints ; Models, Biological ; Models, Theoretical ; Movement ; Muscles ; physiology ; Postural Balance

Objective To explore whether the glomerular podocytes can be damaged by aristolochic acid. Methods Thirty-two male SD rats were equally divided into the following 2 groups:model group in which the rats received the extract of Aristolochia manshuriensis Kom (AmK) by gavage; control group only received tap water by gavage.24 h urinary protein excretion was measured at the end of the 1st and 4th week,and SDS-PAGE gel electrophoresis was performed to detect the protein in urine.At the end of the 4th week,all the rats were sacrificed and the glomeruli were isolated by laser capture microdissection technique.The mRNA expression of nephrin,podocin,CDA2P,podocalyxin and podoplanin in isolated glomeruli was determined by RT-PCR,and the average width of glomerular foot process was measured by electron microscopy and image analysis. Results At the end of the 4th week,24 h urinary protein excretion in the model group was significantly higher than that in the control group (P＜0.01) and the urinary albumin content in model group was also obviously increased.The average width of glomerular foot process in the model group was significantly larger than that in control group (P＜0.01).The mRNA expressions of nephrin,podocin,CDA2P,podocalyxin and podoplanin in glomeruli were significantly down-regulated in the model group compared with the control group,which decreased by 34％,62％,56％,50％(P＜0.01) and 27％ (P＜0.05),respectively. Conclusions Aristolochic acid can damage the glomerular podocytes,resulting in the down-regulation of nephrin,podocin,CD2AP,podoplanin and podocalyxin mRNA expression, the segmental widening of foot process, and increased urinary protein excretion.

In order to evaluate the ability of human standing balance scientifically, we in this study proposed a new evaluation method based on the chaos nonlinear analysis theory. In this method, a sinusoidal acceleration stimulus in forward/backward direction was forced under the subjects' feet, which was supplied by a motion platform. In addition, three acceleration sensors, which were fixed to the shoulder, hip and knee of each subject, were applied to capture the balance adjustment dynamic data. Through reconstructing the system phase space, we calculated the largest Lyapunov exponent (LLE) of the dynamic data of subjects' different segments, then used the sum of the squares of the difference between each LLE (SSDLLE) as the balance capabilities evaluation index. Finally, 20 subjects' indexes were calculated, and compared with evaluation results of existing methods. The results showed that the SSDLLE were more in line with the subjects' performance during the experiment, and it could measure the body's balance ability to some extent. Moreover, the results also illustrated that balance level was determined by the coordinate ability of various joints, and there might be more balance control strategy in the process of maintaining balance.
Acceleration ; Biomechanical Phenomena ; Humans ; Models, Biological ; Motion ; Nonlinear Dynamics ; Postural Balance ; physiology

In order to develop safe training intensity and training methods for the passive balance rehabilitation train- ing system, we propose in this paper a mathematical model for human standing balance adjustment based on T-S fuzzy identification method. This model takes the acceleration of a multidimensional motion platform as its inputs, and human joint angles as its outputs. We used the artificial bee colony optimization algorithm to improve fuzzy C--means clustering algorithm, which enhanced the efficiency of the identification for antecedent parameters. Through some experiments, the data of 9 testees were collected, which were used for model training and model results validation. With the mean square error and cross-correlation between the simulation data and measured data, we concluded that the model was accurate and reasonable.
Algorithms ; Cluster Analysis ; Fuzzy Logic ; Humans ; Models, Theoretical ; Postural Balance

Due to the characteristics and environmental factors, electrocardiogram (ECG) signals are usually interfered by noises in the course of signal acquisition, so it is crucial for ECG intelligent analysis to eliminate noises in ECG signals. On the basis of wavelet transform, threshold parameters were improved and a more appropriate threshold expression was proposed. The discrete wavelet coefficients were processed using the improved threshold parameters, the accurate wavelet coefficients without noises were gained through inverse discrete wavelet transform, and then more original signal coefficients could be preserved. MIT-BIH arrythmia database was used to validate the method. Simulation results showed that the improved method could achieve better denoising effect than the traditional ones.
Algorithms ; Arrhythmias, Cardiac ; Databases, Factual ; Electrocardiography ; Humans ; Signal Processing, Computer-Assisted ; Wavelet Analysis

Aim The m_5AChR-G_ 11? fusion protein was expressed by baculovirus-Sf9 cells system, then using it to identify the specific agonists and antagonists for m_5AChR via detecting the affinity of GDP and m_5AChR-G_ 11?. Methods The m_5AChR-G_ 11? fused cDNAs were generated via a two-step PCR protocol and inserted into pBacPAK9 virus vector. We expressed m_5AChR-G_ 11? fusion protein and m_5AChR protein using baculovirus-Sf9 cell system. [ 3H]QNB and [ 35S]GTP?S binding tests were performed to detect the expressional level of receptor proteins and determine the affinity of GDP and m_5AChR-G_ 11? fusion protein. Results The expression level of m_5AChR-G_ 11? was (47.6?3.2) nmol?g -1 protein. The affinity of GDP to G_ 11? partner changed in the presence of different muscarinic ligands. IC_ 50 values of GDP in the presence of ACh, YM796, Oxotremorine, Methixene, Dextimide and atropine were 128.0, 72.1, 68.5, 16.2, 14.9 and 9.7 ?mol?L -1 respectively, and that in the absence of muscarinic ligand was 20.8 ?mol?L -1. Conclusion The m_5AChR-G_ 11? fusion protein has the pharmacological specificity of M_5 receptor and the efficient coupling interaction of the two partner. Affinity of GDP to ligand bound m_5AChR-G_ 11? fusion protein represents the species of muscarinic ligands. ACh is a full agonist for m_5AChR-G_ 11? fusion protein, YM796 and oxotremorine are partial agonists, while methixene, dextimide and atropine are antagonists.

Objective To study the reconstructive treatment of the different types of neurofibroma and neurofibromatosis in different locations. Methods 37 patients with neurobibroma or neurofibromatosis were reviewed, including 8 cases with simple suture after excision, 9 cases with skin grafting in situ, 12 cases with skin flap grafting. The main points of the treating methods for different types of neurofibroma and neurofibromatosis were discussed, and the chief clinical manifestations, therapeutic principle and notices of the operation were then summarized.Results These 37 patients, including 25 cases of neurofibroma, 11 cases of neurofibromatosis typeⅠ and 1 case of neurofibromatosis type Ⅱ, were satisfied with the results after reconstructive operation. Conclusion The methods of reconstructive operation of neurofibroma and neurofibromatosis, such as simple suture after excision, skin grafting in situ, skin flap grafting, the use of skin soft tissue expansion, microskin grafting and so on, must be selected according to the different type and location of the neurofibroma and neurofibromatosis. The reconstructive operation must guarantee the best recovery of the visage and the function on the basis of the most degree of tumor excision.

BACKGROUND:Studies have found that Wudi Dan can suppress local inflammatory response of the lesioned joints to protect the articular cartilage. OBJECTIVE:To verify the effect of Wudi Dan on chondrocyte viability and apoptosis as wel as the therapeutic effect on osteoarthritis. METHODS:Rat chondrocytes were cultured in serum medium containing Wudi Dan, and the effects of Wudi Dan on cel viability and apoptosis were observed by comparison with the control group. Rabbit model of knee osteoarthritis was constructed using modified Hulth method. Rabbit models were divided into two groups:Wudi Dan group treated with Wudi Dan and control group treated with normal saline, twice a day, consecutively for 4 weeks. Therapeutic effect of Wudi Dan on knee osteoarthritis was observed;cel viability and apoptosis were observed under microscope;the levels of interleukin-1 and matrix metal oproteinase-3 were determined using immunohistochemical method. RESULTS AND CONCLUSION:The apoptotic rate of chondrocytes was significantly lower in the Wudi Dan group than the control group. Pathological findings of the rabbit knee joints showed that the control group had more severe damage to the articular cartilage than the Wudi Dan group. Immunohistochemical staining revealed that in the Wudi Dan group, the cytoplasm and extracel ular matrix were colored light and there were a smal number of positive cel s as wel as low expression of interleukin-1 and matrix metal oproteinase-3. The results suggest that Wudi Dan can effectively protect against articular cartilage lesions, reduce inflammation, and have a good therapeutic effect on osteoarthritis. Its mechanism may be related to inhibition of chondrocyte apoptosis, reduction of cytokine production and inhibition of protein expression of matrix metal oproteinase.