前交叉韧带重建后急停起跳过程中膝关节应力的有限元分析

背景：已有研究分析了前交叉韧带重建患者术后完成不同动作时健患侧运动学、动力学等运动特征,假设前交叉韧带重建术后患者在完成急停起跳动作时健侧前交叉韧带von Mises应力较患侧高,半月板和股骨软骨的von Mises应力较患侧低。目的：通过探究前交叉韧带重建患者健患侧膝关节软组织的应力响应特征,以期为降低该人群发生前交叉韧带二次损伤及慢性膝关节骨性关节炎等继发性损伤提供参考。方法：运用红外光点运动捕捉系统(Nokov)和测力台(Bertec)采集前交叉韧带重建患者急停起跳时膝关节运动学和动力学特征,通过欧拉角计算方法和逆动力获得膝关节三维角度和三维力矩参数,并将膝关节三维角度和力矩作为边界和加载条件分别载入健患侧膝关节有限元模型,进行数值仿真,比较健患侧膝关节内部结构在实际运动载荷下的应力分布情况。结果与结论：(1)在水平向后第一地面反作用力峰值时刻,患侧膝关节屈曲角、内收角明显大于健侧,且健侧垂直地面反作用力高于患侧。此外,健侧垂直地面反作用力峰值出现在急停起跳阶段的4%-6%,而患侧出现在急停起跳阶段的15%-17%,表现出健侧腿较患侧先着地的运动模式。(2)有限元分析显示健侧前交...     

直线前进变换为侧向跨步切入动作时的下肢生物力学变化

背景:侧向跨步切入动作是运动领域最常见的进攻技术,这显著增加了运动员膝关节受伤的风险,但目前相关侧向跨步动作的生物力学表现策略及下肢关节负荷特征并不十分清楚。目的:选择大学女子甲组篮球、足球运动员进行侧向跨步切入下肢动作策略,进行生物力学测试,并分析下肢关节的运动学及动力学参数,从而为运动员及教练员预防下肢伤害,尤其是膝关节十字韧带损伤提供重要参考。方法:选择某高校女子甲组足球及篮球各12名运动员作为研究对象,利用三维测力台及运动图像拍摄系统同步获取其侧向跨步切入动作的相关运动学及动力学参数,并运用SPSS 21.0分析软件对相关数据进行处理分析。该试验方案经天津体育学院伦理委员会批准。结果与结论:①足球运动员有较大的着地瞬间踝关节跖屈角度及髋关节外展角度、最大踝关节外翻角度、膝关节屈曲及内旋角度、膝关节屈曲及内旋角度变化量;②足球运动员有较大的踝关节外旋与髋关节内收力矩峰值,篮球运动员则有较大的踝关节跖屈力矩峰值;③篮球运动员有较小的前后分力制动第一及第二峰值、垂直分力第一峰值及较大的前后分力推蹬力峰值;④结果表明,跨步切入动作过程中,足球运动员习惯于前足着地方式进行急停,进而产生较高的地面反作用力,并增加膝关节屈曲角度进行缓冲,同时有较大的踝关节外翻角度及膝关节内旋角度,而篮球运动员在切入过程中膝关节屈曲角度较少,不利于下肢关节对地面反作用力的缓冲,并进而增加前十字韧带损伤风险。     

躯干运动控制对落地过程中膝关节生物力学指标的影响

目的 明确躯干运动控制对单腿落地过程中膝关节生物力学的影响。方法 招募20名健康男性篮球运动员，采用 Vicon 运动捕捉系统、Kistler 三维测力台、Noraxon表面肌电测试系统测量在躯干控制条件下单腿落地过程中膝关节运动学、动力学和表面肌电的参数。结果 深吸气落地和带杆落地与自然落地比较在触地时刻膝关节屈曲角、峰值屈曲角、峰值屈曲力矩有统计学差异,触地时刻膝关节屈曲角、峰值屈曲角显著增大，峰值屈曲力矩显著减小；深吸气落地和带杆落地膝关节峰值外翻角、峰值外翻力矩及膝关节腘绳肌、股四头肌肌肌电活动量差异无统计学意义。结论 深吸气或带杆落地降低了篮球运动员落地运动中前交叉韧带（anterior cruciate ligament，ACL）损伤的风险，研究结果 为篮球运动员落地运动中ACL损伤预防提供理论基础。     

排球运动起跳过程中踝关节的生物力学特性

文题释义： 急停起跳：在激烈的排球比赛中,急停起跳动作是运动员比赛过程中出色完成扣球、拦网、跳发球、跳传球等技术所必不可少的关键阶段,也是运动员获得较好起跳高度的关键实施环节。 踝关节的活动范围：研究发现长期从事举重项目的人比正常人的踝关节活动度要小,长期从事游泳项目的人比正常人的踝关节活动度要大。踝关节的活动范围往往还跟运动成绩相关联,如短跑、速滑等竞速性项目运动成绩好的运动员踝关节的活动度也相对较好。 背景：目前对踝关节的生物力学特性研究多集中于方法学的探讨,对复合动作模式下踝关节生物力学特征的研究较少。 目的：分析对排球运动员起跳落地时踝关节的运动学和动力学特性。 方法：研究选取天津体育学院排球专项运动的学生男女各20名。主要采用Vicon三维运动捕捉系统和Kistler三维测力台,同步采集受试者在起跳落地时踝关节运动学与动力学参数,总共获得3次有效数据,利用统计学方法对数据进行对比分析。研究方案的实施符合天津体育学院的相关伦理要求,所有受试者均为自愿参加,并对试验过程完全知情同意。 结果与结论：①发现在该动作模式中,踝关节跖屈角度男性明显小于女性,在起跳阶段踝关节处于内翻和内旋状态,在落地缓冲阶段踝关节处于内翻和外旋状态,且角度男性组略大于女性,此时极易造成踝关节损伤;②三维方向的峰力矩和力值男性组均大于女性;三维方向峰值力矩和力出现的时间男性组晚于女性,而且存在双腿力量不均衡以及双脚不同时着地情况。 ORCID: 0000-0003-4584-148X(鲍春雨) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

预期条件下不同侧切角度膝关节应力状态的有限元分析

目的 探讨预期条件下不同角度侧切触地过程中膝关节运动学、地面反作用力（ground reaction force, GRF）特征以及软骨、半月板的应力状态。方法 采集14名受试者在预期条件下分别进行45°、90°和135°侧切时的运动学和GRF数据，通过Visual 3D逆动力学计算获取膝关节反作用力，基于膝关节三维有限元模型分别对3种侧切角度下触地过程进行数值仿真。结果 预期条件下3种侧切角度在触地过程中的膝关节运动学特征存在显著性差异（P＜0.001），膝关节屈曲程度随侧切角增大而增加；垂直GRF随侧切角增加而显著减小（P＜0.001），水平GRF呈现出相反的趋势；3种侧切角度下，90°侧切时髌骨软骨以及股骨软骨接触应力峰值较大, 前交叉韧带（anterior cruciate ligament，ACL）接触点主应力峰值较大，其次为135°和45°侧切；3种侧切角度下，外侧股骨软骨接触应力峰值均大于内侧。结论 90°侧切运动时膝关节损伤风险更大，135°侧切时膝关节内部的应力状态与90°侧切相比较为良好。预期条件下膝关节损伤风险并不随侧切角增大而升高。     

非预期条件下前交叉韧带重建术后运动员侧切动作下肢运动生物力学特征

目的 量化非预期条件下前交叉韧带重建(anterior cruciate ligament reconstruction, ACLR)术后运动员侧切动作中膝关节生物力学特征,探讨运动员前交叉韧带(anterior cruciate ligament, ACL)损伤潜在风险。 方法 应用红外运动捕捉系统和三维测力台同步采集 30 名 ACLR 男性运动员在预期和非预期条件下侧切动作中健侧、患侧下肢运动学和动力学数据。 应用双因素方差分析对关节角度、关节力矩、地面反作用力( ground reaction force, GRF)等测试指标进行统计分析。 结果 患侧肢体的膝关节屈曲角度、外翻力矩和屈曲力矩显著低于健侧肢体,内旋力矩和胫骨前剪切力显著高于健侧肢体。 与预期条件相比,非预期条件下膝关节屈曲角度、内旋力矩、胫骨前剪切力显著增加。 患侧肢体膝关节外旋角度在预期和非预期条件下均显著高于健侧,非预期条件下健侧肢体侧向 GRF 和前后 GRF 显著小于预期条件,患侧肢体侧向 GRF 显著高于预期条件。 结论 ACLR 运动员进行侧切动作时,相比于健侧,患侧表现出较小的膝关节屈曲角度,较大的膝关节内旋力矩和胫骨前剪切力的生物力学特征,可能存在较大的 ACL 潜在损伤风险;在非预期条件下,ACLR 运动员双侧下肢均表现出膝关节内旋力矩增大,侧向 GRF 增大和胫骨前剪切力增大的生物力学特征,提示 ACL 潜在损伤风险不仅限于患侧,健侧下肢也应加强侧切动作中 ACL 损伤预防。     

两种疲劳方案对落地时下肢运动学和冲击力时频特征的影响

目的比较两种疲劳方案对人体落地动作下肢关节运动学及冲击力时/频域特征的影响。方法选取15名优秀跑、跳类专项男性运动员,利用Vicon运动捕捉系统和Kistler三维测力台比较两种疲劳方案(恒速跑、折返跑+垂直纵跳)前后落地时矢、额状面运动学和地面反作用力(ground reaction force,GRF)时/频域特征。结果(1)两种疲劳方案均会造成髋、膝关节在矢状面上的角度减小、屈曲活动度增加,且采用跑+跳方案时踝关节屈曲活动度、膝关节最大屈曲角速度增加(P0.05),髋关节外展活动度以及髋、膝关节最大外展角速度增加(P0.05);(2)两种疲劳方案前后,冲击力时域特征均无显著差异;采用跑和跑+跳方案,分别在3.51、8.20 Hz及1.17、3.51、7.03 Hz下表现出GRF频谱振幅减小(P0.05)。结论两种疲劳方案均会导致下肢在受到落地冲击时更多采用屈曲着地方式,但跑+跳方案表现更明显且干预时间更短,从实验方法学角度更具优势。研究结果可为研究疲劳后的力特征提供进一步参考。     

士兵负重单脚落地时膝关节生物力学特征以及与等速肌力的关系

目的 分析士兵负重单脚落地对膝关节产生的影响,并探讨与肌力的关系,为日常负重训练提供依据。方法 采用Vicon动作捕捉系统和AMTI测力台分别采集12名士兵学员不负重和负重15 kg从30 cm高度单脚落地时膝关节的运动学和动力学数据,同步采集大腿前后侧肌群表面肌电(surface electromyography, sEMG),并进行膝关节屈伸等速肌力测试。结果 与无负重相比,负重15 kg落地时膝关节屈曲角度和胫骨反作用力显著增加(P<0.05),股直肌、股内外侧肌和股二头肌sEMG最大值均显著增加(P<0.05),其余指标负重前后无显著差异(P>0.05)。伸膝峰值力矩与无负重单脚落地垂直地面反作用力呈显著负相关(P<0.05),其余指标无显著相关关系(P>0.05)。结论 负重15 kg单脚落地增加了膝关节屈曲角度和胫骨反作用力,大腿前后侧肌群的激活可缓解落地时的地面反作用力,肌力对于预防落地损伤具有一定作用。     

踝关节贴扎在优势侧落地动作中对膝关节生物力学特性的影响

目的 研究踝关节贴扎（限制踝关节内翻跖屈）在优势侧单腿落地动作中对膝关节生物力学特征的影响。方法 在踝关节未贴扎和贴扎两个条件下,18位业余运动员执行优势侧单腿落地动作,使用Vicon三维运动捕捉系统、Kistler测力台和Noraxon 表面肌电系统共同采集运动学、动力学、表面肌电数据,进行统计学分析。结果 与未贴扎相比,贴扎后触地时刻的膝关节屈曲角度和接触地面过程中膝关节最大屈曲角度显著性增加,而膝关节最大外翻角度显著性减小。结论 限制踝关节内翻跖屈贴扎可能会降低前交叉韧带损伤的风险。踝关节贴扎的干预方式能够改变在落地动作中膝关节生物力学指标。限制踝关节内翻跖屈贴扎可以作为预防大学生运动员前交叉韧带损伤的有效措施。     

关节镜下自体四股腘绳肌腱前交叉韧带重建术后疗效及影响因素

目的 通过关节镜下应用自体四股腘绳肌腱（semitendinosus/gracilis,ST/G）前交叉韧带(anterior cruciate ligament, ACL)重建术治疗ACL损伤,探讨采用不同手术方式和不同康复训练方式术后的疗效对比及其影响因素。 方法 回顾性分析自2017年1月至2018年3月期间本院收治的ACL损伤患者共80例（80膝）,按照手术方式及康复训练方式不同分为4组,每组20例（20膝）,包括保残专业康复组,保残常规康复组,非保残专业康复组,非保残常规康复组。比较末次随访时4组膝关节功能评分、稳定性试验和本体感觉测量结果。 结果 术后患者随访时间均为12个月。4组术后末次随访时Lysholm和IKDC评分均较术前明显增高（P<0.001）,且四组间有显著性差异（P<0.001）。术后四组患侧与健侧位置觉差异对比均有统计学意义（P<0.001）。基于Lysholm、IKDC评分中末次随访与术前的差值增量、患侧与健侧位置觉差异为因变量,以手术方式和康复训练方式为自变量行双因素方差分析,两自变量对膝关节功能评分和本体感觉恢复影响具有显著性（P<0.001）,并且保残组两评分增量显著高于非保残组（P<0.001）,专业康复组两评分增量显著高于常规康复组（P<0.001）,而保残组位置觉差异显著低于非保残组（P<0.001）,专业康复组位置觉差异显著低于常规康复组（P<0.001）。 结论 关节镜下自体四股ST/G保留下止点残端重建术是治疗ACL损伤的理想手术方案,术后实施分时段、个体化专业运动疗法康复,能够促进膝关节功能和本体感觉恢复,有助于患者尽早康复和重返运动。     

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.     

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.     

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.     

'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.     

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.     

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.     

Der Einfluß von Nahrungsmitteln und Rauchen auf die klinisch-chemische Diagnostik von Phäochromozytom,Neuroblastom und Karzinoid-Syndrom

Zusammenfassung Der Einfluß von verschiedenen Nahrungsmitteln auf Methoden zur Bestimmung von Adrenalin (AD), Noradrenalin (NA), Vanillinmandelsäure (VMS), Metanephrinen (MN), Homovanillinsäure (HVS) und 5-Hydroxyindolessigsäure (5-HIE) im 24 h-Harn zur Diagnose des Phäochromozytoms bzw. Karzinoid-Syndroms wurde untersucht. Die in die Untersuchung einbezogenen Nahrungsmittel waren: Tee, Kaffee, Mandeln, Ananas, Käse, Walnüsse, Vanillepudding, Bananen, Tomaten und Milchschokolade. Außerdem wurde der Einfluß des Zigarettenrauchens auf die Bestimmung von AD, NA, VMS und MN untersucht.Walnüsse führten zu einer starken Erhöhung der 5-HIE-Ausscheidung. Bananen erhöhten die Ausscheidung von AD, NA, VMS, MN und 5-HIE. Kaffee und Ananas bewirkten eine geringe Zunahme der MN-Werte. Rauchen von 20–30 Zigaretten/Tag beeinflußte keine der vier Variablen.Wenn die beschriebenen Methoden benutzt werden, sollte lediglich auf den Verzehr von Bananen und Walnüssen vor und während der Harnsammelperioden verzichtet werden, da die oberen Normgrenzen im Harn überschritten werden könnten. Ein Verzicht auf Kaffee und Ananas in normalen Mengen ist nicht erforderlich. Es besteht kein Anlaß, weiterhin die bisherigen umfangreichen Restriktionen der übrigen Nahrungsmittel beizubehalten.