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排序方式: 共有17条查询结果,搜索用时 718 毫秒
1.
Renewed fieldwork at Hadar, Ethiopia, from 1990 to 2007, by a team based at the Institute of Human Origins, Arizona State University, resulted in the recovery of 49 new postcranial fossils attributed to Australopithecus afarensis. These fossils include elements from both the upper and lower limbs as well as the axial skeleton, and increase the sample size of previously known elements for A. afarensis. The expanded Hadar sample provides evidence of multiple new individuals that are intermediate in size between the smallest and largest individuals previously documented, and so support the hypothesis that a single dimorphic species is represented. Consideration of the functional anatomy of the new fossils supports the hypothesis that no functional or behavioral differences need to be invoked to explain the morphological variation between large and small A. afarensis individuals. Several specimens provide important new data about this species, including new vertebrae supporting the hypothesis that A. afarensis may have had a more human-like thoracic form than previously appreciated, with an invaginated thoracic vertebral column. A distal pollical phalanx confirms the presence of a human-like flexor pollicis longus muscle in A. afarensis. The new fossils include the first complete fourth metatarsal known for A. afarensis. This specimen exhibits the dorsoplantarly expanded base, axial torsion and domed head typical of humans, revealing the presence of human-like permanent longitudinal and transverse arches and extension of the metatarsophalangeal joints as in human-like heel-off during gait. The new Hadar postcranial fossils provide a more complete picture of postcranial functional anatomy, and individual and temporal variation within this sample. They provide the basis for further in-depth analyses of the behavioral and evolutionary significance of A. afarensis anatomy, and greater insight into the biology and evolution of these early hominins.  相似文献   
2.
目的:探讨他克莫司和卡泊三醇软膏治疗四肢斑块状银屑病的疗效和安全性。方法:选取2011年4月至2013年8月于我院诊治的84例四肢斑块状银屑病患者,将患者随机分为A组和B组,每组各42例,分别采用他克莫司和卡泊三醇软膏治疗。评定PASI以及疗效指数,并对用药过程中患者的不良事件进行观察记录。结果:A、B两组患者治疗后各时间点PASI评分与治疗前相比较均显著降低,差异有统计学意义(P0.05);但同一时间组间对比,差异并无统计学意义(P0.05)。A组银屑病患者的总有效率为64.29%,与B组的69.05%相比,差异无统计学意义(P0.05)。结论:他克莫司与卡泊三醇软膏治疗四肢斑块状银屑病均安全有效,且二药相比,疗效相当。  相似文献   
3.
目的:探讨MESS评分在治疗肢体严重软组织损伤中的应用价值。方法:回顾性分析我科2010年8月至2014年5月收治的50例肢体严重软组织损伤患者的临床资料,其中男34例,女16例,年龄23~53岁,平均38岁。所有患者入院时均采用MESS评分表进行评分,根据病情给予清创、保肢或截肢以及创面修复等系列治疗,并随访3个月~3年。按照治疗结果将患者分为保肢组、Ⅰ期截肢组和Ⅱ期截肢组,分析和比较三组的MESS分值、住院天数、手术次数、并发症的发生率及患者满意率。结果:保肢组32例,MESS评分6-11分,平均8.63±1.26分。截肢组18例,MESS评分11-14分,其中Ⅰ期截肢组10例,平均12.60±0.97分;Ⅱ期截肢组8例,平均12.88±0.83分。保肢组患者的MESS分值显著低于Ⅰ期截肢组(P0.05)和Ⅱ期截肢组(P0.05)。此外,保肢组患者满意率显著高于Ⅰ期截肢组(P0.05)和Ⅱ期截肢组(P0.05)。而Ⅰ期截肢组的住院时间、手术次数和并发症发生率均短于或少于Ⅱ期截肢组,患者满意率高于Ⅱ期截肢组(P0.05)。结论:对于MESS评分11分的患者行保肢治疗可收到满意的效果,而对MESS评分11分的患者,采取Ⅰ期截肢的治疗效果优于Ⅱ期截肢。  相似文献   
4.
Alignment of joints with respect to the leg axis reduces the moment arm of external forces and therefore joint torques. Moreover, it affects the gearing of muscle forces and displacements. Thus, it influences tissue stress, cost of support and locomotion, and stability. Assuming that alignment is of general advantage we propose a mathematical criterion quantifying the axial alignment using the static torque equilibrium of a three-segment leg. Using this criterion derived from joint torque minimisation we asked for optimal leg designs (segment lengths and joint angles) at varied leg lengths. The trivial straight is best solution is excluded and the configuration space is restricted by geometrical constraints such as the ground contact. For different total leg lengths we could identify different optimal segment length combinations and appropriately adjusted joint angles. The extended human leg configuration characterised by a short foot and a combination of unequal ankle and knee angles emerges as a global optimum from our analysis. For crouched configurations allowing for larger leg extensions an angle symmetrical 1:1:1 segment length combination is best. The plantigrade optimum is enforced by the requirement of the distal segment (foot) being shorter than the opposite outer segment (thigh), as well as by the ground contact constraint. Different (e.g. digitigrade) geometries might be of advantage in different biological contexts with different constraints. The fact that small mammals use a crouched equal segment design implies that other locomotor requirements such as stability, strain rates, and acceleration distance per step might dominate.Send offprint requests to: M. Günther (Tübingen)  相似文献   
5.
Drawing inferences about locomotor energetics from limb morphology, especially in regard to small differences between individuals, depends critically on valid estimates of lower-limb inertial properties. While there are numerous options for such estimations in the literature, geometric models that involve simple measures and straightforward mathematics combined with the ability to capture individual variation are rare. In this research, we apply a method, originally developed for quadrupeds, that models limb segments as elliptical columns. When the elliptical model is applied to bipeds, it provides a means of estimating limb-segment inertial properties accurately enough to test differences between individuals of similar stature and mass, but with variation in mass distribution and limb length. We test the method against commonly used equations and are able to show the validity of the method for thigh and shank segments.  相似文献   
6.
目的:探讨早期康复锻炼对重型脑外伤患者肢体功能障碍的影响。方法:将62例脑外伤肢体功能障碍患者,随机分为康复护理组(31例)和对照组(31例)。对照组给予神经外科常规治疗和护理;在此基础上,康复护理组采用早期肢体康复锻炼。分别于入选治疗前和治疗后4周、12周进行测评。采用Fugl-meyer评分(FMA)评定运动功能;采用Barthel指数评定日常生活自理能力(ADL)。对比两组FMA和ADL指数。结果:两组患者的Barthel指数和Fugl-meyer评分均有一定程度的改善,康复护理组的改善幅度明显优于对照组(P〈0.01orP〈0.001)。结论:重型脑外伤患者接受早期综合康复护理能明显改善肢体运动功能,提高日常生活活动能力,提高患者的生存质量。  相似文献   
7.
Examination of relative growth and allometry is important for our understanding of the African apes, as they represent a closely related group of species of increasing body size. This study presents a comparison of ontogenetic relative growth patterns of some postcranial dimensions in Pan paniscus, Pantroglodytes, and Gorilla gorilla. Interspecific proportion differences among the three species are also analyzed. It is stressed that reliable ontogenetic information can only be obtained if subadults are examined-growth data cannot be inferred from static adult scaling. Results indicate that some postcranial relative growth patterns are very similar in the three species, suggesting differential extrapolation of a common growth pattern, whereas for other proportion comparisons the growth trends differ markedly among the species, producing distinct shape differences in the adults Interspecific shape changes among the three species are characterized by positive allometry of chest girth and negative allometry of body height and leg length. It is suggested that relative decrease of leg length with increasing body size among the African pongids might be expected on biomechanical grounds, in order to maintain similar locomotor abilities of climbing arborealism and quadrupedal terrestrialism. Relative to body weight or trunk length, the limbs of the bonobo (Pan paniscus) are longer than in the common chimpanzee or the gorilla, with a lower intermembral index. This may most closely resemble the primitive condition for the African apes.  相似文献   
8.
Summary The effects of nitrogen mustard (methylbis-chlorethylamine) on limb organogenesis were studied inPleurodeles waltlii at different stages of fore and hind limb development.The effects of four different doses of nitrogen mustard (1.25; 2.5; 5 and 10 g/ml) on the limb bud mesoderm and epidermis were studied histologically. This analysis was carried out on cylindrical unchondrified hind limb buds treated at stage 45.The effects of these doses on all stages of fore and hind limb development were investigated. This included the effect on the establishment of the proximo-distal sequence (segment chondrification) and the antero-posterior sequence (pre-postaxial zeugopod, basipod chondrification and progressive pre-postaxial organization of fingers and toes.Correlations were established between the mesodermal necrosis observed in hind limb buds treated at stage 45 and the skeletal abnormalities occurring in fore and hind limbs after treatment at all stages of their development.Thus, it appears that the effects of nitrogen mustard on organogenesis demonstrates the existence of a state in the differentiation of the mesoderm that is not revealed by morphological studies.  相似文献   
9.
蒋笑怡  李清平  刘治昆 《蛇志》2012,24(1):15-17
目的研究五步蛇伤后局部组织病变性状,探索五步蛇伤后患肢肿胀的治疗方法。方法选择160例确诊为五步蛇伤患肢肿胀的住院患者随机分为两组,治疗组80例采用针刺拔罐后给予如意金黄散外敷,每天1次;对照组80例采用如意金黄散外敷,每天1次。两组均于治疗5天后观察疗效。结果治疗5天后,治疗组80例伤肢肿胀均消退,显效率为95%,有效率为5%,总有效率(显效+有效)100%;对照组80例,显效率为34%,有效率为39%,总有效率73%。经统计学分析,治疗组的疗效优于对照组,差异有统计学意义(P〈O.05)。结论针刺拔罐后如意金黄散外敷治疗五步蛇伤患肢肿胀疗效显著,且操作简便、无损伤、无毒副作用、无并发症,安全高效,避免了传统上对五步蛇伤后肿胀切开引流减压造成的组织创伤和病人精神负担,同时可大大缩短住院时间,减轻了病人的经济负担,为临床提供了一种治疗五步蛇伤患肢肿胀的新方法。  相似文献   
10.
As part of a larger project examining and comparing the ontogeny of all major taxa of the Branchiopoda in a phylogenetic context, the larval development of Caenestheriella gifuensis (Ishikawa, 1895), a Japanese spinicaudatan ‘conchostracan’, is described by scanning electron microscopy. Seven different larval stages are recognised, in most cases based on significant morphological differences. They range in length from about 200 to 850 μm. Nauplius 1 has a plumb and lecithotrophic appearance with a rounded hind body and a labrum with an incipient medial spine. Limb segmentation is mostly unclear but the second antennae have more putative segments delineated than are expressed in the later stages. Feeding structures such as the mandibular coxal process and antennal coxal spine are only weakly developed. Nauplius 2 is very different from nauplius 1 and has three large spines on the labral margin and two long caudal spines. Feeding structures such as the mandibular coxal process and various spines and setae are developed, but whether feeding begins at this stage was not determined. The mandible has developed an ‘extra’ seta on endopod segment 1, absent in Nauplius 1. The segmentation of the second antenna has changed significantly due to fusions of various early segments. Nauplius 3 is like nauplius 2 in morphological detail, but larger and more elongate. Nauplius 4 has developed a pair of small anlagen of the carapace and rudiments of the first five pairs of trunk limbs, and the coxal spine of the antenna has become distally bifid. Nauplius 5 has a larger carapace anlage, externally visible enditic portions of the elongate trunk limbs, and a pair of primordial dorsal telson setae. Nauplius 6 has a larger and partly free carapace and better-developed, partly free trunk limbs with incipient enditic, endopodal, and exopodal setation. A pair of caudal spines, dorsal to the large caudal spines, has appeared. Nauplius 7 is quite similar to nauplius 6 but is larger and has slightly longer caudal and labral spines; also, the setation of the most anterior trunks limbs is better developed. The larval development is largely similar to that of other spinicaudatans. The larval mandible, which is evolutionarily conservative within the Branchiopoda, reveals a setation pattern similar to that of the Anostraca and Notostraca (two setae on mandibular endopod segment 1). Most other spinicaudatans and all examined laevicaudatans share another setal pattern (one seta on mandibular endopod segment 1), which could indicate a close relationship among these taxa. The second antenna undergoes a special development, which provides an insight into the evolution of this limb within the Branchiopoda. In nauplius 1 the basipod, endopod, and exopod are all superficially divided into a relatively high number of segments. In later nauplii some of these have fused, forming fewer but larger segments. We suggest that this ontogeny reflects the evolution of antennae in the conchostracans. Various aspects of the morphology of the antennae are discussed as possible synapormorphies for either the Diplostraca or subgroups of the Conchostraca.  相似文献   
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