Many people engagingin medical scienceasked me,"You’ve beenworking on the exploration of Holistic Integrated Medicine（HIM）for quite awhile.What is the progressyou have made in your research?Have you got your article published?May I beyour first reader?"
Objective To study the impact of simulated weightlessness on cognitive function and neuronal degeneration in rats’ hippocampus, and to explore the mechanism of cognitive impairment induced by weightlessness. Methods Forty SD rats were randomly divided into control group（CON）, 4-week tail-suspension group（SUS）. The Morris water maze test was performed to assess the cognitive function of rats. Hematoxylin-eosin（HE） staining, Nissl staining, Fluoro-Jade B（FJB） staining and TUNEL staining were applied to observe the neuron morphology, degeneration and apoptosis in hippocampus. Tau, m TOR, P53, P21 and Sirt-1 protein expression were analyzed by western blot. Results Com-pared with the control, the 4-week tail-suspended rats exhibited cognitive dysfunction, which was manifested by the increase in swimming distance,protein expression swimming time and escape latency（P<0.01）. According to the HE staining and Nissl staining, neurons were shrunk and loosely ar-ranged with deeply stained nucleus in rats’ hippocampus after 4-week tail-suspension. Moreover, sim-ulated weightlessness led to neuronal degeneration as manifested by the increased FJB positive neurons（P<0.01）. And results of western blot showed that the protein expression of p-TauS404, p-TauS396, p-TauT231, p-m TOR, P53 and P21 in the hippocampus of SUS rats were increased significantly（P<0.05）. Besides, the expression of Sirt-1 was decreased in the SUS rats compared with the control（P<0.01）. TUNEL staining showed an increase in apoptotic neurons in hippocampus in the SUS group. Conclusion Our findings demonstrated that cognitive impairment induced by 4-week simulated weight-lessness may be attributable to neuronal degeneration in hippocampus.
Objective To measure the area of optic nerve subarachnoid and evaluate its sensitivity and specificity to predicting elevated intracranial pressure, so as to explore the mechanism of visual im-pairment and intracranial pressure in astronauts with this noninvasive method. Methods Based on the results of intracranial pressure measured by lumbar puncture, 51 subjects were divided into the elevat-ed intracranial pressure group and the normal intracranial pressure group. The general data were col-lected, and optic nerve sheath diameter(ONSD) at 3 mm behind the ball and area of optic nerve sub-arachnoid space(ONSASA) between 3～7 mm behind the ball were measured by ultrasonic examina-tion and Image J 1.51 analysis software. The prediction ability of these two indexes for elevated in-tracranial pressure was compared by receiver operating characteristic curve and area under curve. Results The optic nerve sheath diameter and the area of optic nerve subarachnoid were larger in the ele-vated intracranial pressure group, and the difference between the two groups was statistically signifi-cant. The area under curve of the area of optic nerve subarachnoid(0.894) to predict elevated in-tracranial pressure was larger than the optic nerve sheath diameter(0.764). Conclusion The measure-ment of area of optic nerve subarachnoid by ultrasonography can predict elevated intracranial pressure, which provides a possible and effective method to study the mechanism of visual impairment and in-tracranial pressure in space environment.
Physical-chemical technology is used in the environmental control and life support systems(ECLSS) of the International Space Station(ISS) to realize the water recycling.During the process, part of the water will enter into the urine brine produced by urine distillation and thus cannot be recy-cled.Techniques that are capable of extracting water from urine brine would enhance the level of total water recovery, and therefore lower the frequency and cost of supply from the earth.The urine brine processing techniques focusing on water recovery was comprehensively reviewed in this paper.The characteristics of 8 technologies from 3 categories including the direct drying technology, the indirect drying technology and the separation drying technology were compared.Then the technology selection of water recovery from urine brine was proposed.In addition, the key points and difficulties in the re-search of water recovery technology was pointed out which may serve as a reference for future researches.
Redox signal is an important regulator of intracellular homeostasis and many biological processes are capable to response to it.Studies have demonstrated that redox oscillates in the body and its period is consistent with that of the clock genes.With the deepening of the researches,large amount of evidence indicates that the transcriptional/translational feedback loops mechanism of circadian rhythm and the non-transcriptional oscillatory mechanism of redox are mutually regulated.The two mechanisms therefore are coupled to produce a timing system with high flexibility.Long-term exposure to microgravity can cause circadian rhythm disorders and oxidative stress damages to the body,increase the health risks of astronauts,and lead to a decline in mission performance and alertness.At present,the effect of microgravity environment on oxidative stress has been studied in depth,but the effect of microgravity on the molecular mechanism of circadian rhythm is rarely studied,and the molecular mechanism of interaction between them has not been fully elucidated.In this paper,the transcriptional oscillation of clock genes and non-transcriptional oscillation of redox were reviewed,the regulation relationship between them and the influence of microgravity on them were summarized.It may serve as a good reference for further deepening the research of space biology and formulating the comprehensive countermeasures of space medicine.
Objective To investigate the effect of posture on the dynamic response of human body during spacecraft skip reentry from the lunar orbit, and to determine the displacement and deformation of hu-man internal organs, thus provide basis for the crew posture setting in the return capsule. Methods The human biomechanics model HUMOS was used to simulate the occupant, and the finite element models of the supine Shenzhou seat and the lying Apollo seat were established. The human body dy-namic response was simulated on the Hyperworks finite element analysis platform. After calibrating the model with centrifuge experimental data, the skip reentry overload curves of Chang’e-like and A-pollo-like were taken as the input of the above models respectively, and further simulation analysis of the human body’s dynamic response was conducted, including the displacement and deformation of important internal organs. Results The shape and peak value of the resultant acceleration response curves of the head, sternum and sacrum in the lying posture were consistent with the input, while in the supine posture, although the shapes of these curves were similar, the sacral vertebra had a rela-tively low peak. The stress state and deformation of internal organs in the lying posture were mainly chest-back compression, while the internal organs in the supine posture were shifted and squeezed un-der the action of +Gx and +Gz. The displacement and deformation of human internal organs in su-pine posture were greater than that of lying posture. Conclusion In view of the minimum displacement and deformation of human internal organs, it is suggested that the priority to should be given the lying posture for posture design of the crew during spacecraft skip reentry from lunar orbit.
Objective. Iron core coils offer a passive way to increase the induced electric field intensity during transcranial magnetic stimulation (TMS), but the influences of core position and dimensions on coil performance have not been elaborately discussed before.Approach.In this study, with the basic figure-of-eight (Fo8) and slinky coil structures, iron core coil optimization is performed with the finite element method considering core position and dimensions. A performance factor combining performance parameters, including the maximum induced electric field, stimulation depth, focus, and heat loss, is utilized to evaluate the comprehensive coil performance.Main results.According to the performance factor, both iron core coils obtain the best overall performance with a fill factor 0.4 and the two legs of the iron core close to the inner sides of the coil. Finally, three prototypes are constructed-the basic, optimized, and full-size slinky iron core coil-and magnetic field detection demonstrates a good agreement with the simulation results.Significance.The proposed systematic optimization approach for iron core coil based on Fo8 and slinky basic structure can be applied to improve TMS coil performance, reduce power requirements, and guide the design of other iron core TMS coils.
目的 研究抑制性和兴奋性自反馈对神经群模型(NMM)alpha振荡的产生和频率调控机制.方法 基于神经群模型,应用分岔分析确定抑制性和兴奋性自反馈产生alpha振荡的参数范围,通过仿真分析验证分岔分析的正确性,并应用频谱分析确定振荡频率.结果 余维一分岔和余维二分岔分析结果表明抑制性自反馈不利于alpha振荡的产生,兴奋性自反馈在一定范围内能够促进alpha振荡的产生.频谱分析结果显示随着抑制性自反馈强度的增加,alpha振荡频率升高;而兴奋性自反馈强度的增加导致al-pha 振荡频率降低.结论 制性或兴奋性自反馈能够抑制或促进神经群模型alpha振荡的产生,二者的协同调控可以对alpha振荡的产生及频率进行更加灵活的双向调节.
空间飞行期间,失重是威胁航天员健康的主要因素之一.肝脏是人体的重要器官,具有物质代谢、蛋白质合成、解毒等许多重要的生理功能.失重/模拟失重可造成人体肝脏血流动力学改变、鼠肝脏形态结构异常、鼠和金鱼氧化应激损伤,抑制鼠肝细胞增殖,鼠的糖、脂肪、酶等物质代谢紊乱.失重或模拟失重对动物肝脏组织形态、细胞增殖分化、氧化应激反应、物质代谢等造成的影响,可能进一步导致动物物质代谢功能、免疫功能、蛋白质合成功能出现障碍.通过综述失重/模拟失重对肝脏影响的研究进展,以期探讨失重对肝脏影响的机理,为制定航天员健康防护措施提供基础数据.
目的 建立贴近实战化训练模式的模拟复杂空战机动(ACM)离心机训练方法.方法 调研提炼飞行训练中典型的载荷参数,编制模拟复杂ACM离心机加速度曲线,7 G曲线为+4.5 Gz 10 s→+2 Gz 5 s→+7 Gz 10 s→+3 Gz 5 s→-1 Gz 5 s→+4 Gz 5 s→+3 Gz 10 s→-2 Gy/+5 Gz 5 s,8 G 曲线为+4.5 Gz 10 s→+2 Gz 5 s→+8 Gz 10 s→+3 Gz 5 s→-0.5 Gz 5 s→+4.5 Gz 5 s→+3 Gz 10 s→-2 Gy/+6 Gz 5 s,9 G 曲线为+4.5 Gz 10 s→+2 Gz 5 s→+9 Gz 10 s→+3 Gz 5 s→0 Gz 5 s→+5 Gz 5 s→+3 Gz 10 s→-2 Gy/+7 Gz 5 s.受试者为12名健康男性,结合HP动作呼吸方式进行了持续12周的针对腿部、腹部、腰部和颈部肌肉的力量训练.12名受试者采用7 G曲线,在力量训练前和力量训练后进行了离心机训练;力量训练后,10名受试者采用8 G曲线、9名受试者采用9 G曲线,进行了离心机训练,记录分析复杂加速度耐力、疲劳评分等指标的变化.结果 力量训练前10名受试者完成了7 G曲线,力量训练后12名均完成了7 G曲线,且疲劳评分显著低于体能训练前(P＜0.01);9名受试者完成了8 G曲线;7名受试者完成了9 G曲线;训练时的呼吸疲劳评分9 G与8 G曲线分别显著高于8 G与7 G曲线(P＜0.05),腿部疲劳评分没有显著差异.结论 建立了离心机模拟复杂ACM训练方法,ACM曲线包含有侧向加速度及推拉动作,兼顾最高载荷并高低搭配,有利于提高飞行员进行长时间复杂空战的能力,具有较高的实际应用价值.
目的 研究可同时用于健康人和脑卒中患者活动分类的传感模块最优位置和数量.方法 23名受试者(14名健康人,9名脑卒中患者)完成步行、刷牙、洗脸和喝水4个动作,每人身上佩戴12个传感模块,各个传感模块集成了加速度、陀螺仪和肌电传感器.采用最大相关-最小冗余算法(mRMR)进行特征选择,随后采用核函数为径向基函数的支持向量机,并利用留一交叉验证法进行活动分类评估.基于活动分类的结果,利用前向逐步选择算法得到每种数量的传感模块(共12种)放置的最佳位置,并得到12个活动识别准确率和其中的最高准确率.计算12个准确率的平均值,准确率超过平均准确率且与最高准确率无显著性差异的最少传感模块组合作为本研究的最优传感模块组合.结果 最优的传感模块组合是采用位于上肢尺侧腕伸肌和下肢股二头肌长头的两个传感模块,其活动分类准确率能达到97.9％±0.94％.结论 采用最优的传感模块组合达到了较高的准确率,其在活动识别方面具有很大的应用潜力.
目的 基于梯度设计的双人图形配对任务,探究其在友谊关系质量评估中的作用.方法 招募陌生组志愿者24对(48人),朋友组40对(80人),利用改编自以往研究的双人图形配对任务,记录其任务表现相关指标(任务完成时间、步数及错误率),并且在朋友组中测量个体水平的情绪表达特质和双人的友谊关系质量.结果 在组间对比中,两组受试者在任务操作的时间维度上存在显著差异(P＜0.05);在朋友组内,任务操作的次数与友谊关系的积极维度间存在显著的相关关系(P＜0.05);任务操作次数随任务难度的变化与友谊关系的冲突得分之间存在显著的相关关系(P＜0.05).结论 双人图形配对任务初始阶段的步数指标可以有效预测友谊关系质量的积极维度,而步数随任务难度增加的相对变化可以有效反映友谊质量的冲突维度.
为系统分析和探讨不同环境下空间定向能力的深层机制及应用进展,从空间维度的视角出发,系统介绍了目前在地面环境中对物理层面的二维和三维空间定向的测量研究和应用,以及在特因环境中对心理层面空间定向的研究范式以及空间定向障碍与训练的研究;在此基础上提出解释空间定向能力的参照原则假说、空间表征策略理论和空间相容性理论以及特因环境的感觉冲突理论,并尝试从工效学角度为空间定向能力的训练与提高从影响因素、任务范式及研究手段3方面提出展望.
目的 探究一种以过硫酸盐为氧化剂对空间站尿液进行预处理,以抑制尿酸固体沉淀、固氨、抑菌的方法.方法 以模拟尿液污水为对象,观察过硫酸盐的自氧化能力对尿酸的降解效果,并对过硫酸盐与酸稳定剂的投加方式、pH和酸的种类、氧化剂含量进行优化.在最优条件下以实际尿液进行小试实验,测试实际尿液经过预处理后的各项指标,包括氨氮值、悬浮物、浊度、细菌总数测试、氨气挥发情况.结果 对于空间站内含有200～300 mg/L尿酸的一般尿液,氧化剂过硫酸钠添加量不少于24 g/L,间隔5 min以内再投加酸稳定剂(硫酸、磷酸、柠檬酸)至尿液废水pH为3以下,可以在24 h内获得良好处理效果.结论 过硫酸盐可以作为空间站尿液预处理剂,实现抑制沉淀、固氨、抑菌的作用.
目的 研究注意力缺陷多动障碍(ADHD)儿童的格兰杰因果网络异常特征,分析二值化网络与权重网络拓扑属性差异.方法 采集22例ADHD儿童与14例健康儿童闭眼静息态脑电数据,使用定向传递函数构建因果连接矩阵,计算两组儿童二值化与权重网络的聚类系数与特征路径长度,并比较两组儿童优势导联对分布差异.结果 ADHD儿童聚类系数增加、特征路径长度降低,且权重网络差异更明显;两组儿童优势导联对都呈现自下而上的信息流模式,ADHD儿童优势导联对分布更加规则,优势导联对信息流主要流向F7、F8两个节点.结论 ADHD儿童脑网络存在异常密集连接和异常高速信息传递,脑网络模块化增强,集成能力减弱,脑网络趋向于规则网络.
目的 研究连续5天反复体位改变对人体超重耐力的影响.方法 6名健康男性作为受试者,进行连续5天的头低位/头高位(HDT/HUT)模式反复体位改变训练,训练中监测主观感觉与体征、心电图和血压等.在训练开始前7天和训练后1天分别进行1次超重耐力测试,监测受试者超重耐力测试过程中的主观感觉、眼水平脉搏波、心率变化情况.结果 与训练前超重耐力测试相比,受试者在训练后超重耐受情况有一定的提高.在"+3.0 Gz,30 s"测试时,眼水平脉搏波上升段显著升高(P = 0.03),平台初段显著降低(P = 0.015);心率在上升段未见显著变化(P = 0.292),平台初段显著 降低(P =0.019).在"+3.5 Gz,30 s"测试时,眼水平脉搏波上升段显著升高(P = 0.02),平台初段显著降低(P＜0.01);心率在上升段显著降低(P＜0.01),平台初段显著降低(P＜0.01).在"+3.8 Gz,30 s"测试时,眼水平脉搏波在上升段和平台初段均未见显著改变(P=0.52和P=0.80);心率在上升段显著降低(P＜0.01),平台初段显著降低(P＜0.01).结论 短期的HDT/HUT反复体位改变训练能够提高人体+Gz超重耐力水平.
目的 研究一种面向飞行员需求的电子飞行包(EFB)可用性评估模型.方法 首先对79名飞行员和11名专家开展可用性调查,通过德尔菲法、文献研究和现场调研结果,构建了由标准、一致性、工作负荷、可记忆性、效率和错误6项一级指标和22项二级指标的层次指标体系;其次提出一种基于AHP-CRITIC 法的模糊综合评价模型,既保留了专家的主观意见又利用了飞行员的客观原始数据;最后通过组合赋权法得到各指标的综合权重值,并解算现有EFB和新版本EFB的评价结果,探究EFB的使用情况.结果 通过对比不同群体以及不同EFB版本的评价结果,最终得出建议改进的优先级为:错误＞一致性＞工作负荷＞标准＞效率＞可记忆性.结论 基于AHP-CRITIC法的模糊综合评价模型具有可行性和有效性,可为后续的再设计和优化提供依据.
目的 研究某新型运输机(简称A)和已列装运输机(简称B)飞行人员本场及长航时飞行作业负荷特点规律,为制定相关的航卫保障措施提供参考依据.方法 采用自认劳累负荷量表(RPE)、斯坦福嗜睡感量表(SSS)、NASA任务负荷指数(NASA-TLX)结合心率监测及心率变异性分析的方法,以32名两型运输机飞行人员(A13人,B19人)为研究对象,于飞行前、中、后开展主观负荷程度、生理参数的变化情况分析比较,探讨两型运输机飞行人员的作业负荷变化特点.结果 飞行后,两型运输机飞行人员RPE、SSS评分增加非常显著(P<0.01),着陆阶段NASA-TLX评分非常显著高于其他飞行阶段(P＜0.01).飞行中,A型运输机飞行人员心率变异性指标RMSSD、VLF、HFnorm显著低于B型运输机飞行人员(P＜0.05),LFnorm、LF/HF非常显著高于B型运输机飞行人员(P＜0.01),A型运输机飞行人员各心率值显著高于B型运输机飞行人员(P＜0.05).不同飞行阶段中,着陆阶段飞行人员VLF、TP显著高于起飞阶段(P＜0.05),巡航阶段各心率值显著低于起飞、着陆阶段(P＜0.05).结论 两型运输机飞行人员的作业负荷具有共性,精神紧张度在巡航阶段均减轻,着陆阶段均增加;但A型运输机飞行人员心率、交感神经张力、精神紧张度均高于B型,提示现阶段A型运输机飞行人员的作业负荷强度高于B型运输机飞行人员.
目的 提出一种基于深度学习的端到端儿童手骨X光图像骨龄评估框架,以实现高精度全自动骨龄评估.方法 由手骨分割网络和骨龄回归网络组成模型,手骨分割网络采用Mask-RCNN分割出手骨区域,分割后的手骨区域直接输入回归网络进行骨龄评估.其中,回归网络以Xception为基础模型进行改进,在Xception输出后接入卷积块注意模块,以从通道和空间两个独立的维度细化特征映射,来获取更有效的特征;同时,将图像和性别信息作为网络的双输入,通过增加性别信息平衡不同性别的手骨发育差异.在RSNA儿童骨龄挑战数据集上评估模型.结果 预测骨龄的平均绝对误差为4.96个月,超过6个研究团队所用骨龄评估方法的精确度.结论 通过分割手骨区域、嵌入卷积块注意模块并关联性别信息,能提高骨龄评估的精确度,可应用于实际临床评估.
目的 设计并研制囊式充液抗荷服,解决现有航天员和飞行员抗荷装备——充气式抗荷服臃肿、热负荷大、反应滞后、梯度分布难以实现等问题.方法 通过力学仿真分析,进行充液抗荷管路设计,并进行充液抗荷服各部分材料的选取或研制,经过多轮设计、试穿、修改与改进,确认了充液抗荷服最终结构.结果 研制出国内首套充液抗荷服.采用囊式无袖分片式结构,裆部、臀部、膝盖部镂空;左右两侧分布充液管路与腹囊;充液为纯净水,设计充液量约为5 L.充液抗荷服外层选择伸缩率较小的面料,管路采用高强度、高伸长率、水密材料.结论 研制的囊式充液抗荷服结构合理,满足美观度、梯度加压、热负荷小等要求.
