Objective To use MRI susceptibility weighted imaging(MRI-SWI)to examine cerebral microbleeds(CMB)in elderly Parkinson's disease(PD)patients,and analyze the relationship be-tween CMB and cognitive impairment in them.Methods A prospective cohort study was conduc-ted on 80 elderly PD patients admitted to Huai'an No.3 People's Hospital from June 2020 to April 2024.All patients underwent MRI-SWI examination and PD-Cognitive Rating Scale(PD-CRS).According to the results of MRI-SWI examination,they were divided into a CMB positive group(17 cases)and a CMB negative group(63 cases),and based on the results of PD-CRS,they were also assigned into a cognitive impairment group(34 cases)and a normal cognitive group(46 ca-ses).General clinical data were compared between the CMB positive and negative groups,and be-tween the cognitive impairment group and normal cognitive group.CMB type and severity were compared between the cognitive impairment group and the normal cognitive group.Multivariate logistic regression analysis was applied to investigate the relationship between CMB and cognitive impairment in elderly PD patients.Results The CMB positive group had longer PD course,ad-vanced Hoehn Yahr(H-Y)late stage,higher unified Parkinson's disease rating scale(UPDRS)Ⅰscore,and larger ratio of cognitive impairment than the CMB negative group(P＜0.05,P＜0.01).The proportion of cognitive impairment in patients with lobular CMB was higher than that in deep-subtentorial CMB and mixed patients,and the proportion of cognitive impairment in patients with severe CMB was higher than that in patients with mild and moderate CMB(P＜0.05).Multivariate logistic regression analysis showed that the occurrence of cognitive impairment in elderly PD patients was related to the course of disease,H-Y mid stage,H-Y late stage,CMB,and UPDRS Ⅰ score,which may be risk factors for cognitive impairment(OR=1.356,95％CI:1.121-1.640;OR=16.585,95％CI:2.532-108.623;OR=5.786,95％CI:1.073-31.206;OR=6.553,95％CI:1.066-40.281;OR=2.102,95％CI:1.384-3.194).Conclusion The coexistence of CMB in elderly PD patients can increase the risk of cognitive impairment,with a higher risk of cognitive impairment in cerebral lobe CMB and severe CMB.Therefore,early detection is crucial.

Objective Based on construction and verification of the lumbar finite element model, the simulation calculation and injury prediction on dynamic response of normal lumbar model and L5 unilateral and bilateral spondylolysis models of the pilot were carried out, so as to explore the influence of persistent flight overload on normal and spondylolysis lumbar vertebrae of the pilot. Methods The precise finite element model of lumbavertebrae was established using reverse engineering software and computer-aided engineering (CAE) technology based on CT images. The validity of the lumbar vertebrae model was verified by static and dynamic in vitro experiments. The biomechanical simulation analysis on normal and spondylolysis lumbar vertebrae of the pilotunder persistent overload was carried out, and the spinal injury was predicted and analyzed by dynamic response index (DRI) injury evaluation and prediction method. Results The maximum isthmus stress of L5 vertebra in unilateral and bilateral spondylolysis models were 105. 29 MPa and 126. 32 MPa, respectively, which were significantly higher than those in normal model. The L4-5 and L5-S1 intervertebral discs of the spondylolysis model were more prone to premature degenerative changes than those of normal model. Combined with DRI spinal injury prediction method, the probability of spinal injury in normal lumbar vertebrae, lumbar vertebrae with L5 unilateral and bilateral spondylolysis were 0. 001 4% , 2. 26% and 3. 21% , respectively, and the probability of spinal injury was significantly increased after the occurrence of spondylolysis. Conclusions The spondylolysis increases the load of lumbar isthmus under flight overload. The results provide more accurate data support for the formulation of training programs and the development of protective devices to ensure flight safety

Objective To simulate dynamic response of cervical spine of the pilot during typical maneuver flight movements using finite element method, as well as make analysis and prediction on damage failure of the pilot neck during flight by impact injury and fatigue injury model of biological tissues.Methods A geometrically accurate finite element model of the neck was constructed, and validity of the model was verified by relevant examples. Then, the acceleration curves of centrifugal trainer under different modes were loaded for numerical simulation, and impact injury and fatigue injury of tissues were predicted by using the universal cervical injury criterion and the fatigue damage model of biological tissues.Results The maximum stress of the vertebrae and intervertebral disc caused by overload impact was 66.53 MPa and 58.63 MPa respectively during typical maneuver flight. According to the Nij injury criteria, the maximum Nij was 0.096, which was lower than the injury tolerance threshold of 1, and would not cause direct acute injury to cervical tissues. Based on fatigue damage model of biological tissues, it was found that cancellous bone suffered fatigue failure under the condition of uninterrupted repeated loading for more than 40 000 times. Considering the limited flight career of the pilot, the vertebral tissues would not be fractured due to the accumulation of fatigue damage.Conclusions To a certain extent, the results can contribute to formulating pilot training and flight plans, and also provide data support for the development of its protective equipment.

Objective: To explore the mediating effect of self-efficacy between mindfulness and self-esteem. Methods: In this study, 400 junior school students from a middle school in Jiangxi Province was recruited and complete mindful self scale, general self-efficacy scale and self-esteem scale. Results: The scores of mindfulness, self-efficacy, self-esteem were (63.89±9.12), (22.82±4.83) and (26.14±4.43), respectively. Mindfulness and its four dimensions (self-insight, self-acceptance, self-compassion and non-persistence) were significantly positively correlated with self-esteem (r=0.18-0.53, all P<0.01). Mindfulness and its three dimensions (self-insight, self-compassion and non-persistence) were significantly positively correlated with self-efficacy (r=0.22-0.39, all P<0.01). Self-efficacy and self-esteem were significantly positively correlated (r=0.82, P<0.01). Mindfulness positively predicted self-efficacy (β=0.38, P<0.01), self-efficacy positively predicted self-esteem (β=0.74, P<0.01), and mindfulness positively predicted self-esteem (β=0.25, P<0.01). That was, self-efficacy partially mediated the relationship between mindfulness and self-esteem. The mediating effect value was 0.28, accounting for 52.83% of the total effect. Conclusion Mindfulness not only directly affects adolescents' self-esteem, but also influences adolescents' self-esteem through self-efficacy.

Fitting formulas of typical parameters were obtained through analysis of anthropometric parameters of armored car driver and operators. These formulas could be a basis for design of product and equipment of cars, cumulating and updating of basic data of similar sample and edition of relative standards. 76 anthropometric static parameters and 11 functional parameters were chosen, and 1 243 soldiers with armored forces were chosen to be tested. The correlation and fitting formulas of body height, sitting height and other parameters were measured and obtained. We also contrasted measured data with data from GJB1835-1993. The present analysis showed that the correlation between sizes of body length and body height and sitting height was significant. Sizes of body length and enclose size and width direction were all increased compared to those in the 1980s. The present results were consistent with other researchers' current research results. The measured data could be an important basis for the data of young male anthropometric parameters and edition of relative standards and design of specific equipment.
Anthropology, Physical ; statistics & numerical data ; Anthropometry ; Automobile Driving ; Body Weights and Measures ; statistics & numerical data ; China ; Humans ; Male ; Reference Values ; Young Adult

Objective To study the performance evaluation of integration rendezvous and docking(RVD)control by man and machine in order to provide reference for function allocation between man and machine.Method By a rendezvous and docking experimental system,30 male volunteers aged 20～40 took part in the performance evaluation experiments.The RVD integration control success rates and total thruster ignition time were chosen as evaluation indices.Result The experiment showed that if less than three RVD parameters control tasks were completed by the subjects and the rest of parameters control task completed by automation,the RVD success rate would be larger than 80.47% and the fuel consumption would be optimized.In addition,there were ten subjects who finished the whole 6 RVD parameters control tasks by enough train.Conclusion If the astronauts role should be integrated into the RVD control,it is suitable for them to finish the heading,pitch and roll control in order to assure the man-machine system high performance.When astronauts were needed to finish all parameters control,two points should be taken into consideration,enough fuel and unconstraint operation time.

The human workload is of great importance to ergonomic evaluation of man-machine system.The local muscle fatigue is considered to be one of the main indexes.In this paper,the cause of local muscle fatigue,its assessment methods and development trends were described in detail.Some related technological problems about its mechanism,measurement and assessment methods were analyzed and induced.Finally,some views were put forward for discussion.