脑卒中患者运动过程中动力学特征的智能预测

目的 使用主成分分析（principal component analysis,PCA）和反向传播(back propagation,BP)神经网络预测脑卒中患者行走时患侧髋、膝、踝的关节力矩。方法 30例脑卒中患者通过8镜头Qualisys红外光点高速运动捕捉系统和Kistler三维测力台同步采集运动学和动力学数据。通过OpenSim计算脑卒中患者髋、膝、踝患侧关节力矩,采用PCA来筛选累积贡献率达到99%的初始变量,采用标准均方根误差（normalized root mean squared error,NRMSE）、均方根误差（root mean squared error,RMSE）、平均绝对百分比误差（mean absolute percentage error,MAPE）和平均绝对误差（mean absolute error,MAE）、R2作为PCA-BP模型的评价指标。使用肯德尔W系数评价计算关节力矩与预测力矩之间的一致性。结果 PCA数据显示躯干、骨盆、患侧髋、膝和踝关节在x、y、z轴（矢状、冠状、垂直轴）对患侧髋、膝、踝关节力矩具有显著影响。预测值与测量值间NRMSE为5.14%~8.86%,RMSE为0.184~0.371,MAPE为3.5%~4.0%,MAE为0.143~0.248,R2为0.998~0.999。结论 建立的PCA-BP模型可准确预测脑卒中患者行走时的髋膝踝关节力矩,显著缩短测量时间。在脑卒中患者的步态分析中本模型可代替传统的关节力矩计算,为获得脑卒中患者生物力学数据提供新途径,以及为脑卒中患者临床治疗提供有效的方法。     

老年人下楼梯下肢关节做功模式分析

目的 探究下楼梯行走过程中老龄化对老年人下肢关节做功模式的影响,丰富楼梯行走的防跌倒理论。 方法 采用 Vicon 红外运动捕捉系统和 Kistler 三维测力台同步采集青年人和老年人下楼梯行走的运动学和动力学数据,利用下肢关节角度、力矩、功率、做功贡献度指标对下肢关节做功模式进行量化评定。 结果 下楼梯过程中,青 年组和老年组下肢三关节角度、力矩、功率的变化趋势一致。 在优势腿的 1 个支撑相内,老年人的屈髋力矩峰值、伸膝力矩第 1 峰值、第 2 峰值、跖屈力矩第 1 峰值、膝负功率第 1 峰值、第 2 峰值、踝负功率峰值以及髋、膝、踝关节净功均显著降低(P<0. 05);伸髋力矩峰值、髋负功率峰值、踝关节做功贡献度显著增加(P<0. 05),髋、膝关节做功贡献度并未出现显著性差异(P>0. 05)。 结论 在下楼梯过程中,老年人下肢关节力学特征显著降低。 老年人采取不同于青年人的下肢关节做功模式。 老年人通过较大的伸髋姿势抵制躯干的过度前倾,同时采取踝关节做功的代偿模式,提高下楼梯行走的身体稳定性。 建议老年人在锻炼时应以增加膝、踝关节肌肉力量的项目为主,以维持下楼梯的姿势控制能力。     

深蹲动作下三连杆模型的对比分析

目的 探讨三连杆模型用于深蹲动作互动动力学分析的合理性，明确三连杆模型与Visual 3D计算关节力矩的差异来源。方法 选取8名受试者，通过Vicon获取深蹲动作运动学数据，采用拉格朗日第二类方程建立三连杆动力学方程，基于Mathematica编程计算获取关节力矩，与Visual 3D下肢链节段模型计算结果进行对比分析，并采用复相关系数（coefficient of multiple correlation, CMC）评价两者的相似程度。结果 8名受试者髋、膝关节CMC均大于0.85，踝关节CMC在0.50～0.85之间，三连杆动力学方程和Visual 3D计算的关节力矩在髋、膝关节处高度相似，在踝关节处仅呈现中度相似性。结论 三连杆模型可用于深蹲动作的关节力矩分析以及进一步的环节互动动力学分析，但应当考虑由地面反作用力引起的互动力矩（外力矩）对踝关节力矩的影响。     

模拟低重力下步态行走的下肢生物力学分析

目的研究重力水平对步态行走时下肢关节运动的影响规律。方法设计一种可随动悬吊式低重力模拟装置用于不同重力水平的模拟,利用运动捕捉系统和三维测力台对12名受试者在正常重力(1 G)、火星重力(1/3 G)及月球重力(1/6 G)下步态行走时下肢关节运动参数进行测量。结果重力水平降低后,髋、膝关节矢状面的活动范围显著减小(P0. 01),踝关节矢状面的活动范围显著增加(P0. 05),1 G重力下髋、膝关节、踝关节矢状面的活动范围分别为45. 2°、67. 7°、32. 5°,1/6 G重力下髋、膝、踝关节矢状面的活动范围分别为25. 1°、50. 8°、42. 4°。低重力环境下,下肢关节在矢状面上的关节力和力矩明显减小(P0. 01)。结论本研究得到的低重力下步态行走规律与以往使用跑步机得到的研究结果大体相同。航天员在地面可以使用跑步机在低重模拟装置的帮助下开展针对性的月面行走训练。     

冲击载荷作用下运动员下肢动态响应的逆向动力学仿真

目的分析冲击载荷作用下羽毛球运动员下肢关节肌肉的动态响应变化。方法基于Any Body Modeling System软件建立人体肌骨模型,采用实测表面肌电信号进行验证,以运动捕捉系统和测力台测量数据进行模型驱动,对羽毛球右前场蹬跨步上网过程中下肢肌肉肌力、关节力和关节力矩进行逆向动力学仿真与分析。结果所建人体下肢肌骨模型经肌电信号验证有效。羽毛球蹬跨步上网过程中,髋、踝关节Z方向内力峰值显著高于X和Y方向内力峰值,而膝关节X方向内力峰值显著高于Y和Z方向内力峰值;缓冲期,髋关节X、Y、Z方向依次表现为内收力矩、伸髋力矩和内旋力矩,膝关节X、Y、Z方向依次表现为外展力矩、屈膝力矩、外旋力矩,踝关节X、Y方向依次表现为内翻力矩、跖屈力矩,且髋、膝、踝关节X方向力矩峰值显著高于Y和Z方向;股外侧肌、股二头肌、胫骨前肌、腓肠肌内侧在对抗地面冲击载荷时的肌力发挥较大,股直肌、半膜肌、比目鱼肌发挥的作用相对较小。结论建立的下肢肌骨模型可为冲击载荷作用下运动员下肢生物力学特性分析提供技术平台。为避免运动损伤,类似羽毛球前场蹬跨步上网冲击动作中尤其要重视触地瞬间地面反作用力载荷对髋、膝、踝关节前后及内外侧方向生物力学性质的影响,同时在对羽毛球运动员进行专项训练时切勿忽视对股外侧肌、股二头肌、胫骨前肌的专项力量发展。     

基于惯性传感网络的穿戴式步行膝关节力矩估计

目的 通过惯性传感网络(inertial sensor network, ISN)估计多种步态下膝关节内翻力矩(knee adduction moment, KAM)和膝关节屈曲力矩(knee flexion moment, KFM)。方法 12名健康成年男性穿戴8个惯性传感器(位于躯干、骨盆、左右大腿、左右小腿、左右脚)在不同步态下(改变足偏角、躯干摇晃角、步宽和步速)行走。使用ISN,并从中提取生物力学特征作为循环神经网络(recurrent neural network, RNN)模型的输入,用于估计KAM和KFM。结果 整体KAM估计精度：相对均方根误差(relative root mean square error, rRMSE)为8.54%,r=0.84;整体KFM估计精度：rRMSE=6.40%,r=0.94。结论 该RNN模型可作为实验室外膝关节载荷估计的基础,潜在应用领域包括步态训练以及膝关节术后康复效果评估。     

基于Hill肌肉模型的人体关节力矩智能预测

目的人体关节力矩是康复评估和人机交互中非常关键的因素之一。它可以通过人工神经网络(artificial neural network,ANN)模型以肌电等信号作为输入进行预测,但是由于人体结构的复杂性导致缺乏有效方法确定ANN模型的输入变量。为此本文提出了一种基于Hill肌肉模型获取关节力矩神经网络预测最优输入变量的方法。方法采用Hill肌肉模型结合人体几何学知识建立关节力矩,智能预测输入输出关系的数学模型,把Hill肌肉模型中肌肉纤维长度和收缩速度,以及以关节自由度为支点的肌肉力臂等不可活体测量的输入变量,转换成关节自由度所关联肌肉的肌电信号(electromyography,EMG)以及这些肌肉所驱动关节自由度角度和角速度等可在线测量的变量。实验中以本文获取的变量作为极限学习机(extreme learning machine,ELM)的输入,对由1位在跑步机上以0.4、0.5、0.6、0.7和0.8 m/s等5个不同速度行走的右下肢偏瘫患者所获的数据进行测试。为了评估本文所提方法智能预测的泛化能力,实验在两个不同的泛化水平下进行,它们分别是只把3个低速数据(0.4、0.5和0.6 m/s)和全部5个速度的数据用于神经网络的训练并预测所有速度下的关节力矩值。实验通过预测值与反向动力学计算值之间的归一化绝对误差和互相关系数评估。结果本文获取的输入变量与其他关节角和角速度作为输入的方法相比,预测关节力矩值更精准。除右踝关节内外翻外,其他关节力矩预测结果的最大归一化绝对误差为12.93%,最小平均互相关系数为0.89。结论该方法比目前通用多体反向动力学的输入变量少,且可实现关节力矩值的在线预测,为运动康复中实时步态分析和外骨骼机器人控制提供技术支持。     

测量并分析上楼梯过程中下肢关节角变化

目的获取上楼梯运动过程中国人下肢关节活动范围的统计学数据,从而为大屈曲度人工关节设计提供依据。方法设计常规楼梯实验装置,利用运动捕捉系统(Optotrak Certus,NDI)和三维测力台(AMTI,Bertec),建立系统地测量上楼梯过程中下肢运动的方法,并应用此方法对40例样本进行测量。结果计算获得了40例样本在上楼梯过程中,髋关节、膝关节及踝关节在1个运动周期内沿各方向上关节角的变化规律及活动范围,其中髋、膝、踝关节在矢状面上活动范围分别是-1.6°～66.7°,0°～91.4°,-20.8°～22.4°。结论上楼梯运动过程中,髋、膝、踝关节在矢状面上活动度最大,且髋关节和膝关节屈曲度最大。与水平路面上正常行走和慢跑运动中关节运动范围比较,上楼梯运动中,髋关节和膝关节在矢状面上运动范围均较大。     

男性青年踝关节外侧副韧带损伤后行走步态分析

目的 获取青年男性踝关节外侧韧带损伤者行走时踝关节的运动学和动力学参数,探讨损伤者行走步态的生物力学特性。方法 采用Qualisys MCU500三维运动影像捕捉系统与Kistler三维测力台,对踝关节外侧副韧带损伤者与健康者各15名的行走步态进行三维同步测试。结果 踝关节外侧副韧带损伤者竖直方向的地面反力变化平缓;在支撑时相中前期,损伤者前后方向的力要比健康者大;在步态周期的60%之前,损伤者左右方向的力明显大于健康者。损伤者关节跖屈力矩变化与健康者相似,患侧外翻力矩、外旋力矩最大,损伤者健侧输出功率最大。结论 损伤者踝关节的稳定性下降,行走时步态异常,为减少患侧负荷,健侧出现代偿效应,足着地瞬间加速过度到垂直支撑时相。本研究为预防踝关节以及损伤后的临床治疗以及康复训练等提供一定的理论参考。     

老年人搂膝拗步动作的下肢运动协调特征分析

目的 探讨65岁以上健康老年人进行太极拳搂膝拗步动作时下肢运动的协调性和稳定性。方法 30名太极拳练习者随机完成步行和搂膝拗步动作,采用Vicon三维动作捕捉系统收集下肢运动学数据。结果 搂膝拗步动作时,矢状面关节角度和髋-膝和膝-踝关节相位值变换频繁,髋-膝和膝-踝关节的平均相对相角绝对值以及髋、膝关节平均标准差显著小于步行。结论 与步行相比,太极拳搂膝拗步动作时髋-膝和膝-踝关节呈现出更协调稳定的关节间运动模式。太极拳锻炼可能会为老年人提供一种特定的协调训练方式,提高姿势稳定性,预防跌倒发生。     

Renal dysplasia and asplenia in two sibs

A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.     

Schizophrenia in a North Swedish geographical isolate, 1900–1977. Epidemiology, genetics and biochemistry

Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc² (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.     

The dominant diseases of modernized societies as omega-3 essential fatty acid deficiency syndrome: Substrate beriberi

About 1900, modern food selection and processing caused widespread $\text{epidemics}$ of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a $\text{panh}$ypovitaminosis B, i.e., a mixture of $\text{substrate}$ beriberi and $\text{substrate}$ pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse $\text{endemic}$ disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for $\text{primates}$. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.     

What will studies of Fulani individuals naturally exposed to malaria teach us about protective immunity to malaria?

There are an estimated over 200 million yearly cases of malaria worldwide. Despite concerted international effort to combat the disease, it still causes approximately half a million deaths every year, the majority of which are young children with Plasmodium falciparum infection in sub-Saharan Africa. Successes are largely attributed to malaria prevention strategies, such as insecticide-treated mosquito nets and indoor spraying, as well as improved access to existing treatments. One important hurdle to new approaches for the treatment and prevention of malaria is our limited understanding of the biology of Plasmodium infection and its complex interaction with the immune system of its human host. Therefore, the elimination of malaria in Africa not only relies on existing tools to reduce malaria burden, but also requires fundamental research to develop innovative approaches. Here, we summarize our discoveries from investigations of ethnic groups of West Africa who have different susceptibility to malaria.     

HLA in North Colombia Chimila Amerindians

HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.     

'Very sore nights and days': the child's experience of illness in early modern England, c.1580-1720

Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.     

Guidelines for the Validation and Use of Immunoassays for Determination of Introduced Proteins in Biotechnology Enhanced Crops and Derived Food Ingredients

Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.     

Ultracryotomy: development and application (with examples from the yeast cytology) (author's transl)

The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.     

The universal muscular chamber. A basic unit of the genitourinary, cardiovascular, gastro-intestinal, skeletal, cutaneous, respiratory and other systems, endocameral hypertension; and spasm, the key to their idiopathic diseases and arthropathies

Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.