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1.
牛卵形巴贝斯虫的体外培养   总被引:1,自引:0,他引:1  
本试验研究了长期在液氮或-80℃冷冻保存虫株-牛卵形巴贝斯虫(B.ovata)的体外培养方法,并探讨了培养条件,试验结果表明:液氮内保存2年之久的牛卵形巴贝斯虫809814号虫株,先经过BO-SCID小鼠体内大量增殖后,在完全埋头液和37℃,5%CO2,5%O2,90%N2培养箱内能够快速增殖,连续培养45天,继代9次,B.ovata在BO-RBC-SCID小鼠体内染虫率可达15%以上,体外培养最高染虫率为6.3%,染虫率5%以上红细胞可作诊断用抗原的制备材料或用液氮(或冷冻)继续保存。  相似文献   
2.
Spleen cells from Toxoplasma lysate antigen (TLA)-sensitized BALB/c mice showed the strong cytotoxic activity against both natural killer (NK)-sensitive cells (YAC-1 and RL male-1) and NK-insensitive cells (P-815), when incubated with TLA or recombinant human IL-2 (rhIL-2). The increment of TLA concentration in culture medium increased the cytotoxic activity. Treatment of effector cells; spleen cells from TLA-sensitized mice incubated with TLA, with anti-asialo GM1 or anti-Thy-1 plus complement inhibited the cytotoxic activity of effector cells, whereas treatment with anti-mouse Lyt-2.2 serum plus complement had no effect on the cytotoxic activity. Treatment of spleen cells from TLA-sensitized mice with anti-asialo GM1 and/or anti-Thy-1 plus complement inhibited cytotoxic activities of effector cells. These results suggested that spleen cells sensitized with TLA both in vivo and in vitro were asialo GM1 positive and Thy-1 positive, and the majority of cytotoxic cells induced by TLA were similar to lymphokine-activated killer (LAK) cells induced by IL-2.  相似文献   
3.
In the present study, laboratory techniques were used to diagnose canine GM2-gangliosidosis using blood and cerebrospinal fluid (CSF) that can be collected noninvasively from living individuals. Lysosomal acid beta-hexosaminidase (Hex) was measured spectrofluorometrically using 4-methylumbelliferyl N-acetyl-beta-D-glucosaminide and 4-methylumbelliferyl 7-(6-sulfo-2-acetamido-2-deoxy-beta-D-glucopyranoside) as substrates. Main isoenzymes A and B of Hex in leukocytes were also analyzed using cellulose acetate membrane electrophoresis. GM2-ganglioside in CSF was detected and determined quantitatively by using thin-layer chromatography/enzyme-immunostaining method with anti-GM2-ganglioside antibody. In normal dogs, Hex activities could be determined in leukocytes, serum, and CSF and the total activities were markedly reduced in all the enzyme sources in a dog with Sandhoff disease. Electrophoresis of a leukocyte lysate from a normal dog showed that the Hex A and Hex B were not separated distinctively with formation of a broad band, whereas there were no bands in electrophoresis of a lysate from a dog with Sandhoff disease, showing a deficiency in the total enzyme activity. GM2-ganglioside could be detected and determined quantitatively in as little as 100 microl of canine CSE GM2-ganglioside in CSF in a dog with Sandhoff disease increased to 46 times the normal level. In conclusion, the methods in the present study are useful for diagnosis of canine GM2-gangliosidosis. These techniques enable definitive and early diagnosis of canine GM2-gangliosidosis even if tissues and organs cannot be obtained.  相似文献   
4.
Host sialic acid (SA) has recently been suggested to play an important role in erythrocyte (RBC) infection by Babesia spp. The present study attempted to further determine the specific type of SAs important in the RBC invasion. Bovine RBC was found to bear abundant alpha2-3-linked SA residues but not alpha2-6-linked SA in nature, confirmed by flow cytometric analysis of the neuraminidase (Nm)-treated RBCs. Lectin-blot analyses revealed the removal of alpha2-3-linked SAs from the 97-, 33-, and 31-kDa bands by the Nm treatment. Addition of the Nm-treated RBCs into an in vitro culture of B. bovis resulted in a decreased population of the parasitized RBCs. The thin smear samples from the cultures were then observed under a confocal laser scanning microscope after staining with the alpha2-3-linked SA-specific lectin: a selective invasion of B. bovis was found only in the intact RBCs bearing the SAs, but not in the desialylated RBCs. Furthermore, a significant reduction of the parasitized RBCs was also observed in the culture supplemented with exogenous 3'-sialyllactose containing the alpha2-3-linked SAs. However, the complete inhibition of parasite proliferation was not achieved in the culture. These findings indicate that while the alpha2-3-linked SA-dependent pathway is needed for highly efficient invasion of host RBCs by B. bovis, there might also be other potential alternative pathways.  相似文献   
5.
A series of N-(arylalkyl)maleimides was prepared for the reaction of maleic anhydride and N-(arylalkyl) amines, and their antimicrobial activities were examined. All compounds exhibited antibacterial activity against gram-positive bacteria such as Bacillus subtilis and Staphylococcus aureus. Almost all compounds exhibited antibacterial activity against the gram-negative bacterium, Escherichia coli, but were inactive against Pseudomonas aeruginosa. Activities against gram-positive bacteria were independent of the nature of the substituent on the benzene ring or the length of alkyl group, but that against gram-negative bacteria was influenced by these parameters. All N-(arylalkyl)maleimides showed activity against yeasts and mycelial fungi.  相似文献   
6.
Using macrophage scavenger receptor-A knockout (SRKO) mice, we examined the role of macrophage class A scavenger receptors (MRS-A) on the immune response and acquisition of host resistance against repeated infestation with Haemaphysalis longicornis. Except for one batch of nymphs that infested one of the SRKO (SR-/-) mice and showed no appreciable reduction in body weight, all the other groups of nymphs manifested significant decrease in body weight. Both SR-/- and wild type (SR+/+) mice showed a sustained increase in anti-tick antibody titers, but SR+/+ mice showed significantly higher titers. The IFN-gamma assayed in SR-/- mouse immune sera was substantially less compared with that in SR+/+ mice. Immune sera from SR-/- and SR+/+ mice recognized the 51 and 44 kDa, and 44 kDa proteins, respectively, of the salivary gland antigen. The difference in the level of anti-tick resistance manifested by both groups of mice may be influenced by less efficient trapping and processing of tick antigens by macrophages in mice lacking for the macrophage scavenger receptors, and consequently affected the cascade of Th1 and Th2 responses. We have thus obtained valuable data that strongly infer the role of MSR-A in enhancing host defense against repeated infestation with H. longicornis.  相似文献   
7.
In this study, we investigated the morphological identification of Toxocara canis and T. cati eggs on the basis of light and scanning electron microscopic (SEM) observations. T. canis and T. cati eggs used in this study were recovered from the uteri of respective gravid female worms. Measurement of egg size was not helpful in the differentiation of these species, because approximately 90% of eggs measured were of similar size. Using SEM, we were able to differentiate T. canis eggs from T. cati eggs based on their respective characteristic surface structures. Both species have subspherical eggs with markedly pitted surfaces like those of a golf ball, but the surface pitting in T. canis is more coarse than that in T. cati. In this study, however, these differences were not absolute, as 16% of T. canis and 29% of T. cati eggs showed surface pitting that was uncharacteristic of their species. Of the 16% of T. canis eggs that could not be differentiated by surface structure, 3% had pitting resembling T. cati, and the remaining 13% showed intermediate type surface pitting. Similarly, 5% of T. cati eggs resembled T. canis, and 25% of these were of intermediate type. Light microscopic observation yielded results similar to those of SEM, indicating that light microscopy is also a useful tool for the identification of Toxocara eggs.  相似文献   
8.
Bovine babesiosis is a livestock disease known to cause economic losses in endemic areas. The apicomplexan parasite Babesia bovis is able to invade and destroy the host’s erythrocytes leading to the serious pathologies of the disease, such as anemia and hemoglobinuria. Understanding the egress mechanisms of this parasite is therefore a key step to develop new therapeutic strategies. In this study, the possible involvement of Ca2+ in the egress of B. bovis merozoites from infected erythrocytes was investigated. Egress was artificially induced in vitro using calcium ionophore A23187 and thapsigargin to increase Ca2+ concentration in the cytosol of the parasite cells. The increased intracellular Ca2+ concentration following these treatments was confirmed using live cell Ca2+ imaging with confocal laser scanning microscopy. Based on our findings, we suggest a Ca2+ signalling pathway in the egress of B. bovis merozoites.  相似文献   
9.
Idiopathic polyarthritis (IPA) is a very common inflammatory arthropathy in the dog. Canine IPA is diagnosed mainly by detecting increased number of leukocytes in the synovial fluid (SF), which is easily influenced by glucocorticoid therapy. We obtained 31 SF samples from 24 IPA dogs prior to (n=19) and/or after (n=12) 1 to 10 weeks of glucocorticoid therapy. The SF total protein concentrations of IPA dogs were significantly higher than those of dogs with non-arthritis diseases (n=34) and healthy controls (n=10). Our data revealed that the SF total protein concentrations are not influenced by several weeks of glucocorticoid therapy. Hence, the SF total protein concentration is applicable as a diagnostic marker of canine IPA even when the patients are receiving glucocorticoid therapy.  相似文献   
10.
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