全文获取类型
收费全文 | 631篇 |
免费 | 17篇 |
专业分类
林业 | 55篇 |
农学 | 23篇 |
96篇 | |
综合类 | 29篇 |
农作物 | 20篇 |
水产渔业 | 84篇 |
畜牧兽医 | 261篇 |
园艺 | 4篇 |
植物保护 | 76篇 |
出版年
2023年 | 2篇 |
2022年 | 6篇 |
2021年 | 15篇 |
2020年 | 7篇 |
2019年 | 12篇 |
2018年 | 11篇 |
2017年 | 17篇 |
2016年 | 23篇 |
2015年 | 21篇 |
2014年 | 27篇 |
2013年 | 68篇 |
2012年 | 42篇 |
2011年 | 37篇 |
2010年 | 18篇 |
2009年 | 20篇 |
2008年 | 44篇 |
2007年 | 27篇 |
2006年 | 29篇 |
2005年 | 35篇 |
2004年 | 31篇 |
2003年 | 31篇 |
2002年 | 17篇 |
2001年 | 24篇 |
2000年 | 14篇 |
1999年 | 12篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1992年 | 2篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 3篇 |
1970年 | 3篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有648条查询结果,搜索用时 31 毫秒
71.
Fipronil modulation of GABAA receptor single-channel currents 总被引:3,自引:0,他引:3
Fipronil is the first phenylpyrazole insecticide introduced for pest control. Although fipronil is known to inhibit GABA receptors, the detailed mechanism of action remains to be seen. In order to elucidate the mechanism of fipronil interaction with the mammalian GABAA system, single-channel patch clamp experiments were performed using rat dorsal root ganglion neurons. The amplitude of main conductance state (27pS) current was not significantly altered by co-application of 10 microM fipronil and 10 microM GABA. The histograms of open time distribution were fitted to a sum of three exponential functions. After application of 10 microM fipronil, the proportion of the fastest component increased slightly and that of the slowest component decreased slightly. Thus, the mean open time was decreased from 11.4 ms to 7.8 ms by fipronil. The histograms of closed time distribution were fitted to a sum of four exponential functions. Fipronil 10 microM prolonged the slowest time constant resulting in a prolongation of the mean closed time from 29.7 ms to 52.8 ms. Thus, the frequency of channel openings was reduced. Thus, the fipronil suppression of GABA-induced whole-cell currents is caused in part by decreases in the channel open time and the frequency of channel openings. 相似文献
72.
73.
Matsuura Y Suzuki M Hayakawa D Asano M Sasaki M Kitamura N Yamada J Tsubota T Ohtaishi N 《The Japanese journal of veterinary research》2004,51(3-4):167-172
We analyzed the localization of steroidogenic enzymes (P450 scc, 3 beta HSD, P450 arom and P450 c17) in the corpora lutea of two Hokkaido sika deer (Cervus nippon yesoensis) during the early mating season. Two corpora lutea were found in each female and the timing of formation of the corpora lutea seemed different. P450 scc, and 3 beta HSD, positive luteal cells were found in both corpora lutea. The existence of two functional corpora lutea from the early mating season through pregnancy suggests that progesterone secreted by two or more corpora lutea is necessary for maintenance of pregnancy in sika deer. 相似文献
74.
Yamaji D Kitamura H Kimura K Matsushita Y Okada H Shiina T Morimatsu M Saito M 《Veterinary immunology and immunopathology》2004,98(3-4):175-184
Molecule possessing ankyrin-repeats induced by lipopolysaccharide (MAIL) is known as an IkappaB protein induced after administration of bacterial lipopolysaccharide (LPS) to mice. In the present study, we cloned bovine MAIL cDNA and examined its mRNA expression in white blood cells isolated from Holstein cows. Bovine MAIL had more than 80% amino acid identities with murine and human MAILs, highly conserved ankyrin-repeat motifs and PEST-like sequences. Bovine MAIL mRNA was undetectable in isolated peripheral white blood cells, but rapidly induced (<1h) after stimulation by LPS and lipid A in vitro in a dose-dependent manner. The lipid A-induced MAIL mRNA expression was found in polymorphonuclear cells, monocytes/macrophages and total lymphocytes, but not in T-lymphocytes. MAIL mRNA was also induced in vivo in peripheral blood leukocytes of cows after intramammary injection of Escherichia coli derived from coliform mastitis. Thus, bovine MAIL, as rodent MAILs, is induced by inflammatory stimuli in specific immune cells in vitro and in vivo, suggesting a role in inflammatory responses to bacterial infection in cattle. 相似文献
75.
76.
Yasuda D Fujita M Yasuda S Taniguchi A Miura H Hasegawa D Orima H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(11):1447-1451
We evaluated the usefulness of MRI and compared it with CT for diagnosis of mesenteric lymphoma in a dog. The results in the plain CT, dynamic CT and plain MR (T1WI and T2WI) images suggested that the mass was a large single nodular lesion with abundant blood perfusion. On enhanced MRI(T1WI) , the mass was depicted as a tumor with adhesion to the gut wall. Exploratory laparotomy confirmed the mass was consistent with the findings on enhanced MRI. We think that MRI might be a useful imaging tool for diagnosis of canine mesenteric lymphoma. 相似文献
77.
Hayakawa D Sasaki M Akabane C Kitamura N Tsubota T Suzuki M Yamada J 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(11):1463-1466
The testes from 15 adult male Hokkaido Sika deer (Cervus nippon yesoensis) were collected during the rutting season (October and November). We investigated the localization of 4 kinds of steroidogenic enzymes (P450scc, 3betaHSD, P450c17 and P450arom) immunohistochemically in these testicular samples. The specific immunoreactivities to these enzymes were detected only in the cytoplasm of Leydig cells. This differs to the enzyme distributions reported previously in Japanese black bear, Japanese raccoon dog, Hokkaido brown bear and American black bear, in which the same immunoreactivities were detected in Leydig cells, Sertoli cells and/or spermatogenic cells. The current study suggests that in the testes of the Hokkaido Sika deer, testosterone and estradiol-17beta may be synthesized in the Leydig cells only. 相似文献
78.
Yamaji D Kimura K Watanabe A Kon Y Iwanaga T Soliman MM Ahmed MM Saito M 《Domestic animal endocrinology》2006,30(3):239-246
Hepatocyte growth factor/scatter factor (HGF/SF) is a pleiotropic cytokine that plays a crucial role in the embryonic and postnatal development of various organs including the mammary gland. We cloned bovine HGF and its c-Met receptor cDNAs, and examined their expression during mammary gland development in dairy cows. The 2.5-kbp HGF cDNA clone contained a 2190 bp open reading frame coding a 730 amino acid protein, while the 4.8-kbp c-Met cDNA clone contained a 4152 bp open reading frame coding a 1384 amino acid protein. The bovine HGF and c-Met sequences exhibited more than 87% identity with those of other mammals. RT-PCR analysis revealed ubiquitous expression of both HGF and c-Met mRNAs in various bovine tissues tested. HGF mRNA was detected only in the inactive stage of bovine mammary gland development and not in the developing, lactating, and involuting stages, while c-Met mRNA was detected in the inactive and involuting stages. Immunohistochemical analysis demonstrated that the c-Met protein was found on mammary epithelial cells in the inactive, developing, and involuting stages, and on myoepithelial cells in all stages. These results suggest pivotal roles of HGF and c-Met in the development of bovine mammary gland. 相似文献
79.
Takamatsu D Ide H Osaki M Sekizaki T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(11):1225-1227
A gram-positive, catalase-negative, facultatively anaerobic coccus was isolated from a lactating cow with hematuria and urodynia in Japan. The isolate was identified by 16S rRNA gene sequence analysis as Facklamia sourekii. The biochemical and culture characteristics of the isolate were well consistent with those of F. sourekii type strain. Since all F. sourekii strains reported so far were isolated from human clinical specimens, this is the first reported case of F. sourekii isolated from veterinary clinical specimen. 相似文献
80.
Yano S Umeda D Maeda N Fujimura Y Yamada K Tachibana H 《Journal of agricultural and food chemistry》2006,54(14):5203-5207
Flavonoids ubiquitously exist in plants, vegetables, fruits, and teas. We evaluated the effect of dietary apigenin, one of the well-known flavonoids, on the immune system in C57BL/6N mice. Mice were fed experimental diets containing apigenin for 2 weeks. After the experimental period, there was no significant difference in body and organ weights between the control and the apigenin group. The total immunoglobulin (Ig) E levels in mice fed apigenin were significantly suppressed, whereas levels of IgG, IgM, and IgA were not affected. We also examined the effect of the apigenin diet on cytokine expression in mice sera using a cytokine array. The production of regulated upon activation normal T cell expressed and secreted (RANTES) and soluble tumor necrosis factor receptor I (sTNFRI) in mice sera was down-regulated by the apigenin diet. These results suggest that a diet containing apigenin can reduce serum IgE and inflammatory cytokines such as RANTES and sTNFRI in mice. 相似文献