Objective In response to the clinical needs for personalized wrist orthoses,a topological optimization design method was proposed to achieve an integrated macro-and micro-structural optimization of a personalized,lightweight,and comfortable wrist orthosis.Methods A composite biomechanical finite element model of the wrist orthosis and upper limb was established to quantify the effects of the orthosis geometry on its fixation performance and comfort.A multi-condition topological optimization and microstructure design approach was employed to optimize the non-load-bearing areas of the orthosis.The orthosis was manufactured using three-dimensional(3D)-printed polyether ether ketone(PEEK),and the feasibility of the design was validated.Results While maintaining mechanical strength,the weight of the 3D-printed PEEK orthosis was reduced by 28％compared to the traditional orthoses.Both the pressure at the skin contact interface and the results of a subjective questionnaire indicated that test subjects experienced a high level of comfort wearing the orthosis.Conclusions The orthosis design achieved personalization,lightweight structure,and high comfort while ensuring mechanical strength and fixation performance.

Objective In response to the clinical needs for personalized wrist orthoses,a topological optimization design method was proposed to achieve an integrated macro-and micro-structural optimization of a personalized,lightweight,and comfortable wrist orthosis.Methods A composite biomechanical finite element model of the wrist orthosis and upper limb was established to quantify the effects of the orthosis geometry on its fixation performance and comfort.A multi-condition topological optimization and microstructure design approach was employed to optimize the non-load-bearing areas of the orthosis.The orthosis was manufactured using three-dimensional(3D)-printed polyether ether ketone(PEEK),and the feasibility of the design was validated.Results While maintaining mechanical strength,the weight of the 3D-printed PEEK orthosis was reduced by 28％compared to the traditional orthoses.Both the pressure at the skin contact interface and the results of a subjective questionnaire indicated that test subjects experienced a high level of comfort wearing the orthosis.Conclusions The orthosis design achieved personalization,lightweight structure,and high comfort while ensuring mechanical strength and fixation performance.

Objective To evaluate the noise hazard level of a coal mining enterprise, and identify high-risk operation types and people, and to provide a basis for preventing and controlling the health damage caused by noise. Methods A large coal mining enterprise in Shaanxi Province was selected as the research object. The noise monitoring data of the coal mine over the years was used to calculate the noise exposure matrix of each post in the enterprise, and the classification of occupational hazards at workplaces (GBZ/T 229.4-2012) was used to assess the occupational health risk levels. Results Among the 22 noise-exposed positions in the enterprise, the 8-hour working day equivalent sound level in positions of shearer driver, horseshoe driver, crusher driver, shuttle driver, relaxation screen driver, and grading screen driver were all higher than the occupational exposure limit of noise. In 2021, the noise exposure levels of shearer drivers, crusher drivers, and coal-selecting workers were all higher than 90 dB (A), and the occupational hazard level was moderate hazard level. In addition, the noise exposure levels of most other jobs also exceeded the occupational exposure limit. Conclusion The noise hazards in the coal mine industry are mainly concentrated in the posts of the coal mining system, tunneling system, and screening workshop. Among them, the shearer driver, the crusher driver, and the coal preparation workers have higher noise exposure levels. It is recommended to take corresponding noise reduction measures and strengthen the protection level to reduce the noise exposure risk of workers.

Objective To study the influence of walking exercise training on heart function, left heart ventricle structure and plasma brain natriuretie peptide (BNP) concentration in patients with chronic heart failure ( CHF), to explore the sense of exercise training.Methods A total of 223 CHF patients were randomly assigned to a guided rehabilitation group, a non-guided rehabilitation group and a control group.All patients were given basic medicine treatment, and the guided rehabilitation group was administered guided walking exercise training program, while the non-guided rehabilitation group was encouraged to do exercise freely but with no guidance.Blood pressure, 6 min walking distance test, plasma concentration of BNP and echocardiography were measured in all patients before and after exercise training.Results At entry to the study, there was no significant difference among the 3 groups with regard to blood pressure, 6 rain walking distance and BNP level as well as echocardiographic parameters including left ventrieular ejection fraction (LVEF) and left ventricular end-diastolic diameter (LVEDd).A follow-up at the 6th month after intervention, the amount of readmission patients in guided rehabilitation group were significantly less than those in non-guided rehabilitation and control groups ( P < 0.05 ).It was also revealed that the plasma concentration of BNP decreased significantly ( P < 0.01 ) ; LVEF and 6 min walking distance improved significantly ( P < 0.01 ) in the guided rehabilitation group when compared with baseline and 6-month follow-up of the non-guided rehabilitation and control groups.However, there observed no significant change with regard to LVEDd.Conclusion Walking exercise training can improve exercise endurance in CHF patients and is safety; but has no influence on left heart ventricular structure in short time.

Brain atlas provides a spatial reference system on which other images can be interpreted in a consistent way, and it is essential for the brain imaging research. However, because of the differences in structure between occidental and oriental brains, the brain atlas based on Western populations, e. g., the International Consortium for Brain Mapping's 154 T1 Weighted Average Atlas, may not be appropriate for other ethnic groups. Therefore, in the present study, we produce an average brain atlas which is based on the data collected from 100 healthy Chinese volunteers. The differences in brains between the Chinese population and the Western population were also investigated. Comparatively,Chinese brains are wider and shorter in size, and smaller in volume.
Asian Continental Ancestry Group ; Brain ; anatomy & histology ; physiology ; Brain Mapping ; Female ; Humans ; Imaging, Three-Dimensional ; Magnetic Resonance Imaging ; Male ; Reference Values

This study sought to reveal the difference in resting-state brain functions between subjects with major depressive disorder and normal controls. Fifty-three depressed patients diagnosed with DSM-IV and 38 normal controls underwent resting-state functional magnetic resonance imaging (fMRI), and the data were analyzed using a new method called Regional Homogeneity (ReHo). Then voxel wised comparison was made to derive the resting-state brain function differences between groups. Compared with normal controls, depressed subjects showed decreased ReHo in bilateral anterior cingulate cortex (ACC), left medial frontal gyrus, and left middle temporal gyrus. Significant decreased ReHo in ACC might suggest less spontaneous neuronal activities or lower baseline brain activities of ACC in depressed subjects in comparison with normal controls.
Adult ; Brain ; physiopathology ; Case-Control Studies ; Depressive Disorder, Major ; physiopathology ; Female ; Gyrus Cinguli ; physiopathology ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Young Adult

Objective To investigate the brain perfusion changes in patients with refractory depressive disorder (RDD) and non-refractory depressive disorder (NDD) using arterial spin labeling (ASL).Methods Present study included 12 patients with RDD, 37 patients with NDD and 42 controls,and their age, sex and handedness were matched among the three groups.FAIR sequences were performed using a 3 T MR imaging system with an 8 channel phase array head coiL The labelled and controled images were subtracted and then averaged to obtain perfusion-weighted images.The first 2 images were excluded to avoid T, equilibrium effects and then voxel based analysis was performed using SPM2. One way ANOVA analysis using age as covariance ( thresholded at P ＜ 0.01 uncorrected) was performed.Results Patients with NDD showed regional alteration of the brain perfusion, mainly involved in two frontal subcortical circuits, i.e. significantly decreased perfusion in the left frontal and thalamus (the limbic thalamo-cortical circuit) whereas significantly increased perfusion in bilateral hippocampi, fight lentiform and left anterior cingulated gyros (the limbic-striatal-pallidal-thalamic circuit).In contrast, patients with RDD presented significantly decreased perfusion involving bilateral frontal areas (the limbic-thalamo-cortieal circuit) whereby no significantly increased perfusion areas were observed.Conclusion In addition to the reported experimental evidences, our results suggest that the RDD is associated with inactivity of bilateral frontal areas, while the NDD is associated with inactivity of left frontal areas and overactivity of bilateral limbic system.