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1.
膝关节矢状面机构模型   总被引:1,自引:0,他引:1  
建立矢状面上膝关节二维机构模型,求解矢状面髌股关节求解屈膝过程中髌骨与股骨的接触点移动,髌骨倾角、髌韧带倾角变化,髌股关节功能角变化以及髌股接触力和髌韧带作用力的变化等髌股关节运动及动力学参数.依据膝关节主要组成部分的功能及相互间连接关系,以股胫关节交叉四连杆模型为基础,通过对髌股关节的几何描述及力平衡限定,并运用ADAMS软件进行分析计算,计算结果与文献实验结果吻合良好。  相似文献   

2.
目的:报道以膝上内侧血管为蒂大收肌腱转位重建膝关节韧带断裂缺损的应用解剖及术式设计.方法:40侧经动脉灌注红色乳胶成人标本,解剖观测大收肌腱的形态及其血供,2侧新鲜下肢标本模拟手术设计.以膝上内侧血管为蒂大收肌腱转位修复膝关节韧带断裂缺损.结果:应用带血供大收肌腱转位修复胫侧副韧带30例,胫侧副韧带和前交叉韧带8例,胫侧副韧带和后交叉韧带4例,多韧带损伤1例,经随访疗效较为满意.结论:大收肌腱与膝关节毗邻,与膝关节韧带形态近似,以膝上内侧血管为蒂转位修复重建胫侧副韧带尤为理想.  相似文献   

3.
目的 针对单髁膝关节置换(unicompartmental knee arthroplasty, UKA)内侧假体松动和外侧关节软骨退化问题,通过骨肌多体动力学方法研究不同生理活动中UKA关节线安装误差对膝关节接触力学和运动学的影响。方法 以内侧自然关节线为0 mm误差,分别考虑±2 mm、±4 mm、±6 mm共6种关节线安装误差情况,建立7个内侧UKA置换的骨肌多体动力学模型,对比研究步行和下蹲运动中膝关节接触力学和运动学的变化。结果 在步行步态周期70%时,相比于0 mm误差UKA假体关节线升高2 mm时内侧假体接触力增大127.3%,外侧软骨接触力减少12.0%;在UKA假体关节线降低4 mm时内侧假体接触力接近0 N,外侧软骨接触力增大10.1%;胫股关节总接触力在关节线升高和降低2 mm时分别增大19.7%和减小14.2%。在下蹲屈膝100°时,相比于0 mm误差膝关节内侧假体接触力和胫股骨关节总接触力在UKA假体关节线升高2 mm时分别增大31.6%和11.1%,在UKA假体关节线降低2 mm时分别减小24.5%和8.5%,而膝关节外侧软骨接触力变化不大。同时,在步行步态...  相似文献   

4.
目的:报道以膝上内侧血管为蒂大收肌腱转位重建膝关节韧带断裂缺损的应用解剖及术式设计。方法:40侧经动脉灌注红色乳胶成人标本,解剖观测大收肌腱的形态及其血供,2侧新鲜下肢标本模拟手术设计。以膝上内侧血管为蒂大收肌腱转位修复膝关节韧带断裂缺损。结果:应用带血供大收肌腱转位修复胫侧副韧带30例,胫侧副韧带和前交叉韧带8例,胫侧副韧带和后交叉韧带4例,多韧带损伤1例,经随访疗效为满意。结论:大收肌腱与膝关  相似文献   

5.
关节镜下前交叉韧带重建移植物的研究进展   总被引:1,自引:0,他引:1  
膝关节前交叉韧带(Anterior Crueiate LigamentACL)是膝关节重要的静力与动力性稳定结构,与其他韧带一起共同保持胫股关节的正常运动。在解剖学上一般将其分为长而细小的前内侧束(AM束)和大而粗短的后外侧束(PL束),亦有作者将其分为三个束:即前内、中间和后外侧束(AM,IM及PL束)。  相似文献   

6.
目的研究不同前交叉韧带力学特性对膝关节有限元模拟结果产生的影响。方法基于医学图像数据重建包含主要解剖结构在内的膝关节三维有限元模型,并考虑韧带的横观各向同性特性;用同一种韧带本构方程对3种不同前交叉韧带应力应变力学实验曲线进行参数拟合,对比不同的前交叉韧带力学参数对膝关节运动学和生物力学性能的影响。结果不同的前交叉韧带力学特性会得到不同的膝关节位移结果,前交叉韧带内的应力及应变大小有很大变化,但分布的趋势基本相同。结论选取不同前交叉韧带力学特性曲线会影响膝关节有限元分析的仿真结果,今后在关节组织力学性能的设置、模型的构建及验证中要足够重视。  相似文献   

7.
韧带是稳定膝关节的主要组成部分。如何在生物力学模型中模拟韧带将会影响膝关节动力学特性以及韧带力.韧带应变和接触力分布的计算。本文就韧带在生物力学模型中的简化方法及其力学参数的选择以作一综述.并提出建模的具体方法。  相似文献   

8.
目的建立完整的人体膝关节三维有限元模型,并在此基础上建立了用于前交叉韧带重建模拟的胫股骨隧道和人工韧带模型,为进一步分析打下基础。方法以MRI图像作为数据源,运用逆向工程软件Geomagic及有限元分析软件ANSYS9.0,参考大量有关实验测试数据的文献报道,建立所需三维有限元模型。结果建立的膝关节三维有限元模型包括胫腓骨上段、股骨下段、胫股骨软骨层、胫股骨隧道、内外侧半月板、后交叉韧带、内外侧副韧带和髌韧带,几何形状良好。胫腓骨隧道和人工韧带的模拟巧妙简便,基本可以满足有限元分析的需要。结论采用MRI图像建立膝关节三维有限元模型切实可靠,能很好地模拟膝关节内部的真实解剖结构及前交叉韧带重建术中的胫股骨隧道。  相似文献   

9.
ACL和MCL拉伸力学性质实验研究   总被引:20,自引:1,他引:19  
目的 研究了10具新鲜成人尸体膝关节前交叉韧带和内侧副韧带的拉伸力学性质,为临床提供生物力学参数.方法 取正常国人新鲜尸体前交叉韧带和内侧副韧带各20个试样进行单向拉伸实验,得出了破坏载荷、强度极限、最大应变、弹性模量.对实验数据以多项式进行拟合,得出了应力-应变曲线和应力-应变关系表达式.结果 前交叉韧带的拉伸强度极限最大应变弹性模量大于内侧副韧带.  相似文献   

10.
膝关节前交叉韧带的损伤及修复   总被引:3,自引:0,他引:3  
本文就膝关节前交叉韧带附着部位、运动状态及其损伤后检查等作一综述。 L achmann试验对前交叉韧带损伤诊断有重要临床诊断价值。利用自身材料 (如髌腱、股薄肌腱、半腱肌肌腱 )转移重建前交叉韧带 ,手术时间应在伤后 4~ 8周内进行 ,并提出以这些组织结构修复前交叉韧带出现的弊端 ,以及以髂胫束作为替代物的可能性。  相似文献   

11.
Renal dysplasia and asplenia in two sibs   总被引:2,自引:0,他引:2  
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.  相似文献   

12.
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.  相似文献   

13.
About 1900, modern food selection and processing caused widespread 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 panhypovitaminosis B, i.e., a mixture of substrate beriberi and substrate pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse 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 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.  相似文献   

14.
15.
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.  相似文献   

16.
Newton H 《Medical history》2011,55(2):153-182
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable.  相似文献   

20.
Most bodily functions require the coordinated actions of complementary and supplementary paired muscle groups. Where this essential muscular cooperation is lacking, hollow organs may burst and others become literally screwed up, giving rise to many similar spastic diseases such as Torticollis, Twisted ovarian cyst, Torsion of the Testis, Volvulus of the intestines, Varicose Veins, Megacolon, Aortamegaly, Scoliosis, Erb's Palsy, Peyronie's Disease, Main-en-Griffe, Undescended Foot (Pes Cavus), Talipes, Strabismus. Spasm is “panenepidemic” and unclassified examples of Torsion Dystonia and Dyskinesia really are as common as debt and taxes.  相似文献   

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