全文获取类型
收费全文 | 307篇 |
免费 | 31篇 |
专业分类
林业 | 10篇 |
农学 | 4篇 |
基础科学 | 1篇 |
69篇 | |
综合类 | 16篇 |
农作物 | 11篇 |
水产渔业 | 26篇 |
畜牧兽医 | 134篇 |
园艺 | 10篇 |
植物保护 | 57篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 2篇 |
2021年 | 11篇 |
2020年 | 15篇 |
2019年 | 23篇 |
2018年 | 17篇 |
2017年 | 20篇 |
2016年 | 23篇 |
2015年 | 13篇 |
2014年 | 15篇 |
2013年 | 28篇 |
2012年 | 31篇 |
2011年 | 31篇 |
2010年 | 13篇 |
2009年 | 10篇 |
2008年 | 17篇 |
2007年 | 14篇 |
2006年 | 12篇 |
2005年 | 13篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
排序方式: 共有338条查询结果,搜索用时 46 毫秒
71.
Marie M Meyerholz Kirsten Mense Michael Lietzau Ana Kassens Matthias Linden Hendrike Knaack Elisa Wirthgen Andreas Hoeflich Mariam Raliou Christophe Richard Olivier Sandra Hans-Joachim Schuberth Martina Hoedemaker Marion Schmicke 《Journal of veterinary science (Suw?n-si, Korea)》2015,16(4):413-421
This study was conducted to determine if the main components of the somatotropic axis change during the early phase of pregnancy in the maternal blood system and whether differences exist on day 18 after pregnancy recognition by the maternal organism. Blood samples of pregnant heifers (Holstein Friesian; n = 10 after embryo transfer) were obtained on the day of ovulation (day 0), as well as on days 7, 14, 16 and 18 and during pregnant, non-pregnant and negative control cycles. The oncentrations of progesterone (P4), oestrogen, growth hormone (GH), insulin-like growth factor-1 and -2 (IGF1, -2) and IGF-binding protein-2, -3 and -4 (IGFBP2, -3, -4) were measured. The mRNA expressions of growth hormone receptor 1A, IGF1, IGF2, IGFBP2, IGFBP3 and IGFBP4 were detected using RT-qPCR in liver biopsy specimens (day 18). In all groups, total serum IGF1 decreased from day 0 to 16. Notably, IGFBP4 maternal blood concentrations were lower during pregnancy than during non-pregnant cycles and synchronized control cycles. It can be speculated that the lower IGFBP4 in maternal blood may result in an increase of free IGF1 for local action. Further studies regarding IGFBP4 concentration and healthy early pregnancy are warranted. 相似文献
72.
Elisa Boyd Eileen Carpenter Brian T. Ross Nina Zidack Michelle L. Flenniken 《American Journal of Potato Research》2018,95(2):183-190
Potato virus Y (PVY) infection is one of the greatest challenges to seed potato production in the United States. To determine how cultivar and seed type affect the development of systemic PVY infection, Russet Burbank and Russet Norkotah Colorado 3 cultivars were grown from two types of pre-nuclear seed (i.e., plantlets and minitubers) and Generation 3 (G3) tubers and challenged with PVY strain Wilga (PVYN-Wi). Systemic PVY infection was measured by assaying spread of virus from the inoculation site to upper non-inoculated leaves. The Burbank cultivar had a lower incidence of systemic PVY infection compared to the incidence of systemic PVY that developed in the Colorado 3 cultivar. Furthermore, Burbank plants grown from G3 tubers had a lower incidence of systemic PVY infection, as compared to Burbank plants grown from plantlets. Together our results indicate that both cultivar and seed type affect the development of systemic PVYN-Wi infections post-inoculation. 相似文献
73.
Andrea Mencarelli Claudio D’Amore Barbara Renga Sabrina Cipriani Adriana Carino Valentina Sepe Elisa Perissutti Maria Valeria D’Auria Angela Zampella Eleonora Distrutti Stefano Fiorucci 《Marine drugs》2014,12(1):36-53
In the present study we provide evidence that solomonsterol A, a selective pregnane X receptor (PXR) agonist isolated from the marine sponge Theonella swinhoei, exerts anti-inflammatory activity and attenuates systemic inflammation and immune dysfunction in a mouse model of rheumatoid arthritis. Solomonsterol A was effective in protecting against the development of arthritis induced by injecting transgenic mice harboring a humanized PXR, with anti-collagen antibodies (CAIA) with beneficial effects on joint histopathology and local inflammatory response reducing the expression of inflammatory markers (TNFα, IFNγ and IL-17 and chemokines MIP1α and RANTES) in draining lymph nodes. Solomonsterol A rescued mice from systemic inflammation were assessed by measuring arthritis score, CRP and cytokines in the blood. In summary, the present study provides a molecular basis for the regulation of systemic local and systemic immunity by PXR agonists. 相似文献
74.
Valentina Stefanetti Agnese Compagnone Chiara Sordini Fabrizio Passamonti Elisa Rampacci Livia Moscati Maria Luisa Marenzoni 《Topics in companion animal medicine》2018,33(4):122-125
Abortion and neonatal mortality are events that can occur in breeding bitches and queens. It has been reported that up to 55% and 33% of these cases remain without a known cause, respectively, in canine and feline pregnancies. Unusual abortigenic and potentially zoonotic agents, including Coxiella burnetii and Leptospira spp., may be involved in these cases. C. burnetii is able to cause reproductive disorders in cattle, sheep and goats, and cases of abortion have been observed in dogs and cats. Moreover, several outbreaks of C. burnetii infection in humans have been caused by delivering bitches and queens, and some of these animals experienced abortion. Leptospira interrogans sensu lato is able to cause abortion or stillbirth in several animal species and its abortigenic role has occasionally been described in bitches and queens. The aim of this study was to search for C. burnetii and Leptospira spp. DNA in a retrospective series of 103 cases of canine and feline abortion, stillbirth, and neonatal mortality submitted for the identification of possible infectious agents. One hundred and fifty-one specimens were tested using PCR assays and found negative for C. burnetii and Leptospira DNA. However, in 49 samples (47.6%) other infectious causes of abortion, stillbirth, and neonatal mortality were identified. These results showed that C. burnetii and Leptospira spp. are probably not common abortigenic agents or causes of neonatal deaths in dogs. However, given the potential abortigentic and zoonotic role of these agents, surveillance of canine and feline abortion, stillbirth, and neonatal mortality could be advisable for a systematic investigation of these events. 相似文献
75.
Cabrera-Guzmán Elisa Crossland Michael R. Pearson David Webb Jonathan K. Shine Richard 《Journal of pest science》2015,88(1):143-153
Journal of Pest Science - The success of an invasive species can be reduced by biotic resistance from the native fauna. For example, an invader that is eaten by native predators is less likely to... 相似文献
76.
das Araújo Francisca Chagas Bezerra Moura Elisa Ferreira de Rodrigues Simone Miranda de Carvalho Kenny Bonfim Arruda Tavares Eraldo José Madureira Moura Mônika Fecury da Silva Gilvan Ferreira 《Genetic Resources and Crop Evolution》2021,68(5):1809-1824
Genetic Resources and Crop Evolution - The biofortification of cassava (Manihot esculenta Crantz) roots is one of the actual goals of genetic breeding, with the development of roots richer in... 相似文献
77.
Isolation of single human hematopoietic stem cells capable of long-term multilineage engraftment 总被引:1,自引:0,他引:1
Notta F Doulatov S Laurenti E Poeppl A Jurisica I Dick JE 《Science (New York, N.Y.)》2011,333(6039):218-221
Lifelong blood cell production is dependent on rare hematopoietic stem cells (HSCs) to perpetually replenish mature cells via a series of lineage-restricted intermediates. Investigating the molecular state of HSCs is contingent on the ability to purify HSCs away from transiently engrafting cells. We demonstrated that human HSCs remain infrequent, using current purification strategies based on Thy1 (CD90) expression. By tracking the expression of several adhesion molecules in HSC-enriched subsets, we revealed CD49f as a specific HSC marker. Single CD49f(+) cells were highly efficient in generating long-term multilineage grafts, and the loss of CD49f expression identified transiently engrafting multipotent progenitors (MPPs). The demarcation of human HSCs and MPPs will enable the investigation of the molecular determinants of HSCs, with a goal of developing stem cell-based therapeutics. 相似文献
78.
79.
Op den Camp R Streng A De Mita S Cao Q Polone E Liu W Ammiraju JS Kudrna D Wing R Untergasser A Bisseling T Geurts R 《Science (New York, N.Y.)》2011,331(6019):909-912
Rhizobium-root nodule symbiosis is generally considered to be unique for legumes. However, there is one exception, and that is Parasponia. In this nonlegume, the rhizobial nodule symbiosis evolved independently and is, as in legumes, induced by rhizobium Nod factors. We used Parasponia andersonii to identify genetic constraints underlying evolution of Nod factor signaling. Part of the signaling cascade, downstream of Nod factor perception, has been recruited from the more-ancient arbuscular endomycorrhizal symbiosis. However, legume Nod factor receptors that activate this common signaling pathway are not essential for arbuscular endomycorrhizae. Here, we show that in Parasponia a single Nod factor-like receptor is indispensable for both symbiotic interactions. Therefore, we conclude that the Nod factor perception mechanism also is recruited from the widespread endomycorrhizal symbiosis. 相似文献
80.
Gelain ME Antoniazzi E Bertazzolo W Zaccolo M Comazzi S 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2006,35(4):454-459
A 3-year-old, male, domestic shorthaired cat was presented with a 3-day history of anorexia and depression. The cat was moderately dehydrated, had pale, slightly icteric, mucous membranes, oral ulcerations, and mild hepatosplenomegaly. A feline leukemia virus (FeLV) antigen test was positive. CBC results obtained at initial presentation included severe normocytic, normochromic, nonregenerative anemia, severe thrombocytopenia, and marked leukocytosis (>100,000/microL) with 77% eosinophils. After 15 days of treatment with prednisone and doxycycline, the cat had persistent severe nonregenerative anemia (HCT 3.4%), thrombocytopenia (28,000/microL), and extreme eosinophilia (total eosinophils, 123.1 x 10(3)/microL; segmented 103.0 x 10(3)/microL; immature 20.1 X 10(3)/microL). Cytologic examination of aspirates from bone marrow, liver, lymph nodes, and spleen revealed a predominance of mature and immature eosinophils, many with dysplastic changes. The M:E ratio was 96.4. On histopathologic examination, multiple organs were infiltrated by eosinophilic granulocytes. Neoplastic cells in blood and bone marrow stained positive for alkaline phosphatase and were negative for myeloperoxidase, chloroacetate esterase, and alpha-naphthyl acetate esterase. On flow cytometric analysis of peripheral blood, the neoplastic cells were positive for CD11b and CD14. These findings were consistent with chronic eosinophilic leukemia. To our knowledge, this is the first report of chronic eosinophilic leukemia in a cat associated with naturally acquired FeLV infection, in which flow cytometry was used to characterize the neoplastic cells. 相似文献