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排序方式: 共有178条查询结果,搜索用时 15 毫秒
11.
目的观察蛇伤凉血合剂对蝰蛇咬伤的临床疗效。方法将62例病人分为治疗组和对照组,两组均给予常规治疗,治疗组加服蛇伤凉血合剂。观察比较两组预后,局部组织坏死发生率,肢体功能受限发生率,肾损害发生率和血液透析率,住院时间等指标。结果两组病人的临床疗效、肿胀消退时间、疼痛缓解时间、局部坏死发生率、致残率、肾损害发生率和血液透析率、住院时间均有显著性差异(P〈0.05)。结论蛇伤凉血合剂对蝰蛇咬伤有显著疗效。 相似文献
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SE Santana IR Grosse ER Dumont 《Evolution; international journal of organic evolution》2012,66(8):2587-2598
The morphology and biomechanics of the vertebrate skull reflect the physical properties of diet and behaviors used in food acquisition and processing. We use phyllostomid bats, the most diverse mammalian dietary radiation, to investigate if and how changes in dietary hardness and loading behaviors during feeding shaped the evolution of skull morphology and biomechanics. When selective regimes of food hardness are modeled, we found that species consuming harder foods have evolved skull shapes that allow for more efficient bite force production. These species have shorter skulls and a greater reliance on the temporalis muscle, both of which contribute to a higher mechanical advantage at an intermediate gape angle. The evolution of cranial morphology and biomechanics also appears to be related to loading behaviors. Evolutionary changes in skull shape and the relative role of the temporalis and masseter in generating bite force are correlated with changes in the use of torsional and bending loading behaviors. Functional equivalence appears to have evolved independently among three lineages of species that feed on liquids and are not obviously morphologically similar. These trends in cranial morphology and biomechanics provide insights into behavioral and ecological factors shaping the skull of a trophically diverse clade of mammals. 相似文献
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Tooth root morphology as an indicator for dietary specialization in carnivores (Mammalia: Carnivora)
KORNELIUS KUPCZIK DEANO D. STYNDER 《Biological journal of the Linnean Society. Linnean Society of London》2012,105(2):456-471
The Carnivora occupy a wide range of feeding niches in concordance with the enormous diversity in their skull and dental form. It is well established that differences in crown morphology are linked to variations in the material properties of the foods ingested and masticated. However, how tooth root form is related to dietary specialization is less well known. In the present study, we investigate the relationship between tooth root morphology and dietary specialization in terrestrial carnivores (canids, felids, hyaenids, and ursids). We specifically address the question of how variation in tooth root surface area is related to bite force potentials as one of the crucial masticatory performance parameters in feeding ecology. We applied computed tomography imaging to reconstruct and quantify dental root surface area in 17 extant carnivore species. Moreover, we computed maximal bite force at several tooth positions based on a dry skull model and assessed the relationship of root surface area to skull size, maximal bite force, food properties, and prey size. We found that postcanine tooth root surface areas corrected for skull size serve as a proxy for bite force potentials and, by extension, dietary specialization in carnivores. Irrespective of taxonomic affinity, species that feed on hard food objects have larger tooth roots than those that eat soft or tough foods. Moreover, carnivores that prey on large animals have larger tooth root surface areas. Our results show that tooth root morphology is a useful indicator of bite force production and allows inferences to be made about dietary ecology in both extant and extinct mammals. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105, 456–471. 相似文献
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毒蛇咬伤致急性呼吸衰竭的机械通气救治6例 总被引:2,自引:2,他引:0
目的 探讨机械通气救治毒蛇咬伤致急性呼吸衰竭的治疗效果。方法 用机械通气救治6例毒蛇咬伤致急性呼吸衰竭患者。结果 气管内插管是最佳的气道开放方法;控制通气时,理想的参数为潮气量12ml/kg,通气频率20次/分,呼吸比1:2,吸氧浓度0. 4;辅助通气是,压力支持通气为0.3-1.5kPa,触发敏感度为-3mmH2D。气管插管者辅助通气4-6h后撤机及拔管可获得成功。结论 气管内插管及机械通气是救治毒蛇咬伤致急性呼吸衰竭的最有效的方法。 相似文献
17.
目的 为了经济快速分离眼镜王蛇(Ophiophagushannah,Oh)蛇毒中的毒素成分。 方法 用普通离子交换剂于高效液相色谱柱 (HPLC) TSKgel SP-Toyopearl 65 0 SF (4× 1 5 0 mm)层析法 ,实验取得最佳分离条件后 ,将蛇毒样品上柱后进行梯度洗脱 ,各洗脱峰收集后在 Cosmosil 5 C4-AR-3 0 0柱 (4 .6× 1 5 0 mm)上进行逆相 HPLC分析。非单峰组分再进行 HPLC凝胶过滤柱TSKgel Toyopearl HW-40 Fine(4× 2 5 0 mm)层析 ,层析峰组分再进行 HPLC逆相分析。 结果 眼镜王蛇毒经HPLC离子交换柱层析获得了 1 6个蛋白组分 ,其中有 5个组分经逆相 HPLC分析单一组分 ;另外的复合性组分再进行 HPLC凝胶过滤柱层析后又得到 5个单峰蛋白组分。 结论 HPLC离子交换柱层析对分离蛇毒蛋白很有实用价值 ,特别是蛇毒样品量少的情况下 (1 0 ug)也能较好分离。还具有分离时间短 (1 h左右 ) ,无须低温条件等优点。HPLC凝胶过滤柱层析可进一步使蛋白组分得到提纯 相似文献
18.
A. KRISTOPHER LAPPIN PAUL S. HAMILTON BRIAN K. SULLIVAN 《Biological journal of the Linnean Society. Linnean Society of London》2006,88(2):215-222
The Common Chuckwalla [ Sauromalus ater (= obesus )] is a large, sexually dimorphic lizard with a flattened head that takes refuge from predators in rock crevices. Males use their relatively large heads to bite competing males during territorial fights and to restrain females during copulation. Flattened heads with an antipredator function (i.e. seeking refuge in crevices) and enlarged heads with intrasexual competition and reproductive functions suggest possible antagonism between selective pressures on head morphology in males. To examine this hypothesis, we performed a morphometric analysis and measured the bite-force performance of 49 adult chuckwallas. Males had disproportionately wider heads than females, but did not have deeper heads. Males bit with nearly four times the force of females, consistent with the notion of sexual selection for high bite force in males. Although constrained by crevice-wedging behaviour, head depth was a good predictor of bite force in both sexes. In males, however, osteological head width also was a good predictor of bite force. These results are consistent with the hypothesis that head shape in males is under antagonistic selective pressures, which may partly explain the pattern of head shape dimorphism. The disproportionately wide head of males may reflect anatomical modifications to enhance bite force in response to sexual selection in spite of presumed constraints on head shape for crevice-wedging behaviour © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 215–222. 相似文献
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E. J. RAYFIELD 《Zoological Journal of the Linnean Society》2005,144(3):309-316
The engineering analysis technique finite element analysis (FEA) is used here to investigate cranial stress and strain during biting and feeding in three phylogenetically disparate theropod taxa: Coelophysis bauri , Allosaurus fragilis and Tyrannosaurus rex . Stress patterns are generally similar in all taxa with the ventral region of the skull tensed whilst the dorsal aspect is compressed, although the skull is not purely behaving as a cantilever beam as there is no discernible neutral region of bending. Despite similarities, stress patterns are not wholly comparable: there are key differences in how certain regions of the skull contain stress, and it is possible to link such differences to cranial morphology. In particular, nasal morphology can be explained by the stress patterns revealed here. Tyrannosaurus models shear and compress mainly in the nasal region, in keeping with the indistinguishably fused and expanded morphology of the nasal bones. Conversely Allosaurus and Coelophysis models experience peak shear and compression in the fronto-parietal region (which is tightly interdigitated and thickened in the case of Allosaurus ) yet in contrast the nasal region is lightly stressed, corresponding to relatively gracile nasals and a frequently patent internasal suture evident in Allosaurus . Such differences represent alternate mechanical specializations between taxa that may be controlled by functional, phylogenetic or mechanical constraints. Creation of finite element models placed in a phylogenetic context permits the investigation of the role of such mechanical character complexes in the cranium of nonavian theropods and the lineage leading towards modern birds. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 309–316. 相似文献
20.
眼镜王蛇泛素融合蛋白基因和核糖体蛋白L30基因的克隆及分析 总被引:2,自引:0,他引:2
从广西产眼镜王蛇(Ophiophagus hannah)毒腺中抽提总RNA,经mRNA纯化后构建眼镜王蛇毒腺cDNA文库。从所构建的cDNA文库中,随机筛选200个克隆测序,得到两个在进化上高度保守的基因:泛素融合蛋白基因(GenBank登录号为AF297036)和核糖体蛋白L30基因(GenBank登录号是AF297033)。前者cDNA的开放阅读框为387bp,后者为348bp。前者编码128个氨基酸残基组成的泛素融合蛋白前体;后者编码115个氨基酸残基组成的核糖体蛋白L30前体。由cDNA序列推导出的氨基酸序列分析表明,泛素融合蛋白前体包括N-末端的泛素结构域(76个氨基酸残基)和C-末端的核糖体蛋白L40结构域(52个氨基酸残基)。该蛋白为一高碱性蛋白,C末端含有一个“锌指”模式结构。与16个物种比较的结果表明,眼镜王蛇与脊椎动物的泛素融合蛋白氨基酸序列相似度较高,具有高度的保守性。 相似文献