全文获取类型
收费全文 | 295篇 |
免费 | 11篇 |
国内免费 | 3篇 |
专业分类
林业 | 42篇 |
农学 | 5篇 |
基础科学 | 2篇 |
32篇 | |
综合类 | 9篇 |
农作物 | 10篇 |
水产渔业 | 52篇 |
畜牧兽医 | 136篇 |
园艺 | 6篇 |
植物保护 | 15篇 |
出版年
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 8篇 |
2014年 | 13篇 |
2013年 | 18篇 |
2012年 | 20篇 |
2011年 | 24篇 |
2010年 | 13篇 |
2009年 | 13篇 |
2008年 | 16篇 |
2007年 | 19篇 |
2006年 | 14篇 |
2005年 | 22篇 |
2004年 | 16篇 |
2003年 | 18篇 |
2002年 | 11篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1993年 | 1篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有309条查询结果,搜索用时 744 毫秒
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.
K Miyahara T Matsumoto S Tose H Sakurai I Igarashi A Saito T Hirose N Suzuki 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1992,54(1):87-93
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.
4.
Takabatake N Okamura M Yokoyama N Okubo K Ikehara Y Igarashi I 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(10):999-1004
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.
Tomioka I Mizutani E Yoshida T Sugawara A Inai K Sasada H Sato E 《The Journal of reproduction and development》2007,53(4):835-842
The present study was conducted to demonstrate the spindle formation and behavior of chromosomes and microtubules during first division in reconstructed rat embryos produced by somatic cell nuclear transfer (SCNT) with cumulus cell nuclei. To demonstrate the effect of oocyte aging after ovulation on the cleavage of SCNT embryos, micromanipulation was carried out 11, 15 and 18 h after injection of hCG. SCNT oocytes were activated by incubation in culture medium supplemented with 5 microM ionomycin for 5 min followed by treatment with 2 mM 6-dimethylaminopurine (6-DMAP) in mR1ECM for 2-3 h. For immunocytochemical observation, the SCNT embryos were incubated with monoclonal anti-alpha-tubulin antibody and then fluorescein isothiocyanate (FITC)-conjugated goat anti-mouse IgG. Cleavage rates were significantly higher for oocytes collected after 15 and 18 h rather than for those collected 11 h after injection of hCG (56 and 53%, respectively vs. 28%; P<0.05). Premature chromosome condensation occurred before activation of the SCNT oocytes, but adequate spindle formation was only rarely observed. The distribution of microtubules in SCNT embryos after activation was different from those of fertilized and parthenogenic oocytes, i.e., a dense microtubule organization shaped like a ring was observed. Eighteen to 20 h post-activation, most SCNT embryos were in the 2-cell stage, but no nucleoli were clearly visible, which was quite different from the fertilized oocytes. In addition, first division with and without small cellular bodies containing DNA was observed in the rat SCNT embryos in some cases. The present study suggests that reorganization of transferred nuclei in rat SCNT embryos may be inadequate in terms of formation of the mitotic assembly and nucleolar reorganization. 相似文献
6.
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
7.
Goto A Hayasaka D Yoshii K Mizutani T Kariwa H Takashima I 《The Japanese journal of veterinary research》2002,49(4):297-307
We compared the biological properties of Oshima 5-10 (tick-borne encephalitis [TBE] virus isolated in Hokkaido, Japan) and Sofjin-HO (Far-Eastern subtype TBE virus) including plaque formation, virus replication and virus protein synthesis in BHK-21 cell cultures to reveal strain differences. We also determined the complete nucleotide sequences of both strains and compared the deduced amino acid sequences. Plaques of Oshima 5-10 were smaller than those of Sofjin-HO. Virus titers in culture fluid of Oshima 5-10 were 1/100 of those of Sofjin-HO at 9 and 12 hr after infection. Less viral protein and RNA syntheses of strain Oshima 5-10 was observed than with Sofjin-HO. Genetic analysis revealed 1.4% of amino acids to differ with Sofjin-HO. No difference between the two strains was detected in the motif sequence of the viral enzyme, cleavage sites of viral protein or glycosylation sites of NS1. 相似文献
8.
Kabamoto S Bhagat NA Suzuki H You M Kamio T Tsuji N Claveria FG Nagasawa H Igarashi I Toyoda Y Fujisaki K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(4):355-359
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
9.
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
10.
Comparison of flower color with anthocyanin composition patterns in evergreen azalea 总被引:2,自引:0,他引:2
Daiki Mizuta Takuya Ban Ikuo Miyajima Akira Nakatsuka Nobuo Kobayashi 《Scientia Horticulturae》2009,122(4):594-602
In evergreen azaleas, major anthocyanins were detected from petals of wild species and cultivars by HPLC analysis. Depending on flower color, all samples were divided into three groups: red, purple or white, using the Japan color standard for horticultural plants. The chromatic components a* and b* values of red group samples showed a convergent distribution, whereas those of purple group samples showed a wider distribution. According to the HPLC analysis, red group samples had two to four major anthocyanins, and those of the purple group had two to six major ones. In contrast, no anthocyanins were detected in the white group petals, although anthocyanidins were detected. These results suggest that the anthocyanin constitution of the purple group flowers is more varied than that of the red group flowers, and this wider variety among purple flowers contributes to extending the diversity of flower color in evergreen azalea. 相似文献