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排序方式: 共有311条查询结果,搜索用时 31 毫秒
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Ayano OMURA Hideki ENDO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):43-47
The digestive organs in decapodiform cephalopod species morphologically vary by
individual lifestyle. We examined the following six species of adult decapodiformes
cephalopods representing different habitats: Todarodes pacificus, Loligo
bleekeri, Loligo edulis, Watasenia
scintillans (pelagic), Sepia lycidas and Euprymna
morsei (benthic). L. bleekeri and L. edulis
possess a bursiform cecal sac connected to the cecum. Pelagic species have a single
digestive gland smaller than in benthic species. T. pacificus has an oval
digestive gland larger than that of L. bleekeri and L.
edulis, which possess withered-looking and smaller digestive glands. In
contrast, the digestive glands in benthic species are paired. S. lycidas
and E. morsei have well-developed and larger digestive glands than those
of the pelagic species. Well-developed digestive duct appendages are found in benthic
species. In qualification of the mass of digestive organs, pelagic species have smaller
stomachs, digestive glands and digestive ducts’ appendages than benthic species. Because
pelagic species need to swim, they may possess smaller stomachs and larger cecums for more
rapid digestion. A smaller digestive gland may have the advantage of reducing the body
weight in pelagic species for rapid swimming. In contrast, since benthic species require a
longer time for digestion than pelagic species, they compact more food in their stomachs
and absorb nutrients via more organs, such as the digestive grand and digestive duct
appendages, in addition to cecum. 相似文献
3.
Corrigan LJ, Winfield IJ, Hoelzel AR, Lucas MC. Dietary plasticity in Arctic charr (Salvelinus alpinus) in response to long‐term environmental change.Ecology of Freshwater Fish 2011: 20: 5–13. © 2010 John Wiley & Sons A/S Abstract – In the face of widespread environmental change impacts, there is a need to better understand mechanisms promoting flexibility and resilience of ecosystem components to such change to inform strategies for conservation. Glacial relict species are especially vulnerable to such changes. We investigated the behavioural responses of a native, glacial relict species, Arctic charr (Salvelinus alpinus) to long‐term environmental changes. It was hypothesised that changes in feeding behaviour would occur as a key intermediary to reduction in habitat availability (through climate change and eutrophication) or competitive interactions [with introduced roach (Rutilus rutilus)]. Stomach content analysis was used to assess the diet of 199 charr caught from Windermere, United Kingdom, in the months of March, June, September and November 2003–2007. The results were compared to data from 1940 to 1951 prior to the environmental changes and revealed a marked increase in the contribution of benthic invertebrates in the present diet. Stable isotope analysis confirms the results of the stomach analysis, suggesting that the charr have switched their diet from zooplanktivory towards benthivory. We discuss the possibility that habitat modification and roach population expansion in Windermere have contributed to changes in charr diet. Complementary studies suggest that this diet shift is more likely to be a response to the increasing roach population than to habitat modification; however, further study in Windermere would be required to elucidate the exact mechanism. Long‐term data sets such as these provide information that is useful for determining the directivity of ecological change and the capability of species to respond to change. 相似文献
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探讨不同年龄组家兔胃肠道各段CD8+T细胞的分布特征,为进一步研究CD8+T细胞的作用奠定形态学基础。采用免疫组织化学技术对不同年龄组(幼年组、青年组、老年组)家兔胃肠道内CD8+T细胞进行染色、观察及统计分析。结果显示,家兔的CD8+T细胞多呈圆形、椭圆形或呈不规则形。在不同年龄组家兔,胃肠不同部位的分布有如下特点:家兔的CD8+T细胞主要分布于胃肠道的固有层中;青年组CD8+T细胞的分布数量显著高于幼年组和老年组;各肠段之间CD8+T细胞分布的数量差异不显著,但其分布的总量按照小肠、大肠、胃的顺序依次降低。研究结果显示,CD8+T细胞在家兔小肠的分布最多,并且其数量随着年龄的增长呈现先上升后下降的趋势,青年家兔胃肠的分布最为丰富。 相似文献
5.
Mariarita Romanucci Paolo E. Crisi Maria Veronica Giordano Morena Di Tommaso Francesco Simeoni Leonardo Della Salda 《Journal of veterinary diagnostic investigation》2021,33(1):112
A 14-y-old spayed female Labrador Retriever was presented with an 8-mo history of chronic vomiting. Abdominal ultrasound and gastrointestinal endoscopy revealed a mass protruding into the gastric lumen, with cytologic features suggestive of sarcoma. A partial gastrectomy was performed; the gastric body and antrum were thickened, with a cerebriform appearance of the mucosal surface. Histologic examination revealed a submucosal neoplastic proliferation of fusiform cells variably arranged in irregular bundles and scattered whorls. Fusiform cells strongly reacted to antibodies against vimentin, S100, and neuron-specific enolase; glial fibrillary acidic protein was moderately and multifocally expressed. Pancytokeratin, KIT, α–smooth muscle actin, and desmin were nonreactive. Histologic and immunohistochemical findings suggested a diagnosis of gastric sarcoma with features referable to a non-GIST (gastrointestinal stromal tumor), non–smooth muscle NIMT (non-angiogenic, non-lymphogenic intestinal mesenchymal tumor). The overlying gastric mucosa was thickened by elongated and dilated gastric glands, predominantly lined by intensely periodic acid-Schiff–stained mucous cells. This altered mucosal architecture was suggestive of Ménétrier-like disease. Although this disease has been hypothesized to predispose to gastric adenocarcinoma in dogs, an association with gastric sarcoma has not been documented previously in the veterinary literature, to our knowledge. 相似文献
6.
Sabnis S 《Veterinary research communications》1999,23(7):425-447
The oral route is presently the preferred route of drug delivery. Poor oral bioavailability results in variable concentrations of drugs in the plasma and variable pharmacological responses, in addition to higher product costs. The unique canine physiology, anatomy and biochemistry makes designing canine dosage forms a challenging exercise. This article reviews the physicochemical, physiological, pharmacokinetic, pharmacological and formulation factors that can influence the drug availability of the oral formulations in dogs in an effort to provide a source of data to aid development of canine drug products with superior bioavailability. 相似文献
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Preliminary evidence for the presence of Helicobacter-like bacteria was sought in 395 porcine gastric samples by a urease test. Of the samples, 37% (146/395) were urease-positive and 82% (82/100) of the Gram-stained urease-positive samples showed large, tightly spiralled organisms. Several methods were applied to culture the organisms but isolation was unsuccessful, contaminant organisms being considered to be one of the major problems. PCR with Helicobacter genus-specific primers for 16S rRNA and ureB genes, and primers for H. pylori vacA and cagA genes were tested with 102 urease-positive biopsy samples. The PCR results showed some evidence for the presence of the urease and the vacA genes in porcine Helicobacter-like bacteria and raises the possibility of pathogenicity by these organisms. 相似文献
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