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排序方式： 共有624条查询结果，搜索用时 15 毫秒
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Zimmerman KL Bender HS Boon GD Prater MR Thorn CE Prater D Robertson JL Saunders GK Sponenberg DP Inzana KD Lanz OI Wright E 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2000,29(1):29-34
Abstract: The cytologic and histologic features of 2 intracranial and 2 spinal (extramedullary cervical) canine meningiomas were compared. Cerebrospinal fluid analysis in 2 cases revealed mild, mixed cell pleocytosis, primarily composed of small lymphocytes and monocytoid cells, with a moderate increase in total protein concentration. Cytologic features suggestive of meningioma included cells with both epithelial and mes-enchymal characteristics and a tendency towards cell clustering. Tumor location also was useful in making a diagnosis. The 4 meningiomas differed histologically from one another, and included angioblastic, psam-momatous, meningotheliomatous, and microcystic anaplastic types, which conformed to a classification scheme for human meningiomas. The classification scheme could not be applied to cytologic specimens. 相似文献
23.
Kurt A.Zuelke 《中国家禽》2007,29(20):30-31
美国农业部目前在依阿华州艾姆斯已完成了其动物卫生研究、诊断及动物产品检验设施的全面的、现代化的重建,共投入4.6亿美元,成为有史以来的美国农业部最大的建设项目.…… 相似文献
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25.
Kurt Mantel 《Forstwissenschaftliches Centralblatt》1937,59(16):513-525
Ohne Zusammenfassung 相似文献
26.
Kurt Mantel 《Forstwissenschaftliches Centralblatt》1937,59(15):488-497
Ohne Zusammenfassung 相似文献
27.
Kurt Mantel 《Forstwissenschaftliches Centralblatt》1937,59(2):33-50
Ohne Zusammenfassung 相似文献
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29.
Kurt Mantel 《Forstwissenschaftliches Centralblatt》1931,53(1):8-31
Ohne Zusammenfassung 相似文献
30.
Heike Kappes Kurt Jordaens Frederik Hendrickx Jean-Pierre Maelfait Luc Lens Thierry Backeljau 《Landscape Ecology》2009,24(5):685-697
Habitat fragmentation is a major cause for species loss, but its effect on invertebrates with low active dispersal power,
like terrestrial gastropods, has rarely been studied. Such species can not cross a hostile habitat matrix, for which the predictions
of island theory, such as positive relations between species richness and patch size, should apply. In order to test this
prediction, we studied gastropod species diversity by assessing gastropod assemblage characteristics from 35 sites in 19 fragments
of deciduous old-growth forests in the Lower Rhine Embayment, Germany. Assemblages differed between larger (≥700 ha) and smaller
forests (<400 ha), those of large forests held a higher percentage of forest species. Although α-diversity was similar between
the two forest size classes, small forests often comprised matrix species, resulting in a higher β-diversity. Edge effects
on the species richness of matrix species were noticeable up to 250 m into the forest. Hierarchical partitioning revealed
that distance to disturbances (external edge, internal edges like roads) explained most assemblage variables, whereas forest
size and woodland cover within a 1 km radius from the sites explained only a few assemblage variables. Densities of two forest-associated
species, Discus rotundatus and Arion fuscus, decreased with forest size. Yet, forest size was positively correlated with richness of typical forest species and densities
of Limax cinereoniger. The latter species seems to need forests of >1,000 ha, i.e., well above the size of most fragments. In conclusion, the prediction
is valid only for forest species. The response to fragmentation is species specific and seems to depend on habitat specialization
and macroclimatic conditions.
Jean-Pierre Maelfait: Deceased. 相似文献