首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   338篇
  免费   23篇
  国内免费   1篇
林业   20篇
农学   16篇
  34篇
综合类   5篇
农作物   13篇
水产渔业   53篇
畜牧兽医   202篇
园艺   5篇
植物保护   14篇
  2024年   1篇
  2023年   2篇
  2022年   11篇
  2021年   23篇
  2020年   8篇
  2019年   13篇
  2018年   15篇
  2017年   12篇
  2016年   22篇
  2015年   10篇
  2014年   24篇
  2013年   28篇
  2012年   29篇
  2011年   28篇
  2010年   8篇
  2009年   17篇
  2008年   21篇
  2007年   19篇
  2006年   17篇
  2005年   11篇
  2004年   8篇
  2003年   13篇
  2002年   7篇
  2001年   4篇
  2000年   4篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1985年   1篇
  1984年   1篇
  1980年   1篇
排序方式: 共有362条查询结果,搜索用时 62 毫秒
91.
92.
Japanese Black (JB) calves are more susceptible to infectious diseases compared to Holstein (Hol) calves. To clarify the immunological differences between JB and Hol calves, expression of cytokine messenger RNA (mRNA) was examined using peripheral CD4+, CD8+ and γδ T cells. Healthy calves, 24 from each species, were examined. Blood samples were obtained from calves at 1 week, 1 month and 3 months old, eight calves for each age of each species. Peripheral blood mononuclear cells were stimulated with phytohemagglutin (PHA), and T cell subsets were isolated by positive selection using magnetic cell sorting (MACS). Levels of interlekin (IL)‐2, IL‐4, IL‐10 and interferon (IFN)‐γ mRNA in three T cell subsets were analyzed. WC1‐N1+ γδ T cell percentages were significantly lower in JB calves at 1 week and 1 month of age compared to Hol calves. In addition JB calves had significantly lower IL‐2, IL‐10 and IFN‐γ mRNA in WC1‐N1+ γδ T cells at 1 and 3 months of age, whereas there were no significant differences in cytokine mRNA of CD4+ and CD8+ cells between the two groups. Decreased cytokine mRNA and cell number of peripheral γδ T cells may affect negatively on the immune system of JB calves.  相似文献   
93.
94.
95.
Urdangarin  MAITENA  Shigeru  KATAYAMA  Ryo  SATO  Hiroki  SAEKI 《Fisheries Science》2004,70(5):896-902
ABSTRACT:   Carp myosin was conjugated with alginate oligosaccharide (AO) through the Maillard reaction under low relative humidity, and the functional properties of the myosin-AO conjugate were investigated to clarify the role of myosin in the functional improvement of fish myofibrillar proteins (Mf) by the glycosylation. The findings were as follows. First, myosin became highly solubilized at lower NaCl concentrations by conjugation with AO and NaCl-dependence of the solubility was lost when > 12% of the available lysine residues were reacted with AO and 50 µg/mg of AO was attached to myosin. Second, the thermal stability of myosin was effectively improved by conjugation with AO. Heat-treatment at 50°C for 6 h has no effect on the solubility of the myosin-AO conjugate regardless of the NaCl concentration. Third, the improved functionalities of myosin conjugated with AO remained even at a nearly isoelectric point. The improving effect of AO-conjugation on the characteristics of myosin was almost the same as Mf reacted with AO. Therefore, it is apparent that that improved functionalities of the glycosylated Mf reflect the functional changes of myosin.  相似文献   
96.

Canine hemangiosarcoma (HSA) has an extremely poor prognosis, making it necessary to develop new systemic treatment methods. MicroRNA-214 (miR-214) is one of many microRNAs (miRNA) that can induce apoptosis in HSA cell lines. Synthetic miR-214 (miR-214/5AE), which showed higher cytotoxicity and greater nuclease resistance than mature miR-214, has been developed for clinical application. In this study, we evaluated the effects of miR-214/5AE on stage 2 HSA in a mouse model. Mice intraperitoneally administered with miR-214/5AE (5AE group) had significantly fewer intraperitoneal dissemination tumor foci (median number: 72.5 vs. 237.5; p?<?0.05) and a lower median foci weight (0.26 g vs. 0.61 g; p?<?0.05). Mice in the 5AE group had increased expression of p53 and cleaved caspase-3, and a significantly lower proportion of Ki-67-positive cells, than those in the non-specific miR group. Notably, no significant side effects were observed. These results indicate that intraperitoneal administration of miR-214/5AE exhibits antitumor effects in an intraperitoneal dissemination mouse model of HSA by inducing apoptosis and suppressing cell proliferation. These results provide a basis for future studies on the antitumor effect of miR-214/5AE for HSA.

  相似文献   
97.
The pituitary is an important endocrine tissue of the vertebrate that produces and secretes many hormones. Accumulating data suggest that several types of cells compose the pituitary, and there is growing interest in elucidating the origin of these cell types and their roles in pituitary organogenesis. Therein, the histogenous cell line is an extremely valuable experimental tool for investigating the function of derived tissue. In this study, we compared gene expression profiles by microarray analysis and real-time PCR for murine pituitary tumor-derived non-hormone-producing cell lines TtT/GF, Tpit/F1 and Tpit/E. Several genes are characteristically expressed in each cell line: Abcg2, Nestin, Prrx1, Prrx2, CD34, Eng, Cspg4 (Ng2), S100β and nNos in TtT/GF; Cxcl12, Raldh1, Msx1 and Twist1 in Tpit/F1; and Cxadr, Sox9, Cdh1, EpCAM and Krt8 in Tpit/E. Ultimately, we came to the following conclusions: TtT/GF cells show the most differentiated state, and may have some properties of the pituitary vascular endothelial cell and/or pericyte. Tpit/F1 cells show the epithelial and mesenchymal phenotypes with stemness still in a transiting state. Tpit/E cells have a phenotype of epithelial cells and are the most immature cells in the progression of differentiation or in the initial endothelial-mesenchymal transition (EMT). Thus, these three cell lines must be useful model cell lines for investigating pituitary stem/progenitor cells as well as organogenesis.  相似文献   
98.
A pad equivalent for a dog was prepared as a substitute for the loss of footpad. In addition to the time course of formation on epidermal morphogenesis, we investigated expressions of alpha(6) integrin subunit as adhesive molecule, and laminin and type IV and VII collagens as extracellular matrices of basement membrane components. Epithelium of the pad equivalent was thick enough to be easily confirmed at 5 days at the air-liquid interface, but many creases appeared on it at 7 days, and it shrank at 10 and 14 days. Keratinocytes were increased in 4 to 5 cell layers at 1 day at the air-liquid interface, differentiating into basal cell layer. Granular and corneal cell layers were confirmed until 5 days, and maintained their shape at least until 14 days. Alpha 6 integrin was expressed at almost the same fluorescent intensity as native pad tissue at 1 day at the dermal-epidermal junction. Laminin and type IV collagen were intermittently expressed at 5 and 10 days, respectively, at the dermal-epidermal junction, and at 14 days the fluorescence showed almost the same intensity as native pad tissue. The expression of type VII collagen was discontinuous at 2 days at the dermal-epidermal junction, but remained as it was at 14 days. The present findings suggested that although the formation of anchoring fibrils in basement membrane was incomplete, the pad equivalent in the dog was reconstructed similar to a native pad by epidermal morphogenesis.  相似文献   
99.
The association of the polymorphism of bovine leukocyte antigen ( BoLA-DRB3 ) genes, identified by the polymerase chain reaction sequence-based typing (PCR-SBT) method, with resistance and susceptibility to mastitis caused by Streptococci , coagulase-negative Staphylococci, Escherichia coli and Staphylococcus aureus was investigated. Blood samples for DNA extraction were collected from 170 Holstein cows (129 mastitis and 41 healthy cows) from 5 districts in Chiba prefecture, Japan. Susceptibility or resistance to the mastitis-causing pathogens was thought to vary by the presence of amino acid substitutions at the 9, 11, 13, and 30 positions. DRB3*0101 and DRB3*1501 had amino acid motifs of Glu9, Ser11, Ser13, and Tyr30, and they were considered to have susceptibility to all 4 mastitis pathogens. In contrast, DRB3*1101 and DRB3*1401 had amino acid motifs of Gln9, His11, Gly13, and His30 in these positions, and they also had Val86, so these alleles were considered to have resistance to Streptococcal and coagulase-negative Staphylococcal mastitis. However, in the case of Escherichia coli mastitis, amino acid substitutions at the 9, 11, 13, and 30 positions had little effect, but rather substitutions at the 47, 67 positions of pocket 7, and at the 71, 74 positions of pocket 4, Tyr47, Ile67, Ala71, and Ala74, were associated with resistance. This motif was present in DRB3*1201 .  相似文献   
100.
Tumour necrosis factor‐related apoptosis‐inducing ligand (TRAIL) is an apoptosis‐inducing cytokine that shows potential therapeutic value for human neoplasms, and is effective in some canine tumours; however, its potential for killing canine hemangiosarcoma (HSA) cells is unknown. Thus, we evaluated the proapoptotic effect of TRAIL in nine canine HSA cell lines. Cells (JuA1, JuB2, JuB2‐1, JuB4, Re11, Re12, Re21, Ud2 and Ud6) were cultured with three recombinant human TRAILs (rhTRAILs): TRAIL‐TEC derived from Escherichia coli, TRAIL‐TL derived from mammalian cells and isoleucine zipper recombinant human TRAIL (izTRAIL) containing an isoleucine‐zippered structure that facilitates trimerization. TRAIL‐TEC did not decrease the cell viability in any of the cell lines tested, whereas the other two rhTRAILs effectively decreased the viability of all cell lines as assessed by the WST‐1 assay. In canine HSA cells, izTRAIL induced apoptosis more effectively than TRAIL‐TL. In JuB4, Re12, and Ud6 cells, izTRAIL increased the activation of caspase‐3 and caspase‐8 and caused poly (ADP‐ribose) polymerase degradation. Moreover, izTRAIL treatment increased the proportion of Annexin V+/ Propidium iodide (PI)? apoptotic cells and nuclear fragmentation in izTRAIL‐sensitive cells. These results show that rhTRAIL can induce apoptosis in canine HSA cells, but the sensitivity of TRAIL was different depending on the cell lines. Therefore, TRAIL could be an effective therapeutic agent against canine HSA, but the specific mechanism of resistance should be determined to clarify under what conditions this treatment would be most effective.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号